Background: Coronal restoration of endodontically treated teeth (ETT) with mesio-occluso-distal (MOD) cavities is of a great importance in long-term success of the treatment. This study evaluated the effect of fiber reinforcement on the fracture resistance (FR) of ETT restored with flowable or paste bulk (PB)-fill composite resin compared to conventional composite (CC) resin. Materials and Methods: In this in vitro experimental study, eighty maxillary premolars were divided into eight groups (n = 10). The first group was left intact (G₁) and the other groups received MOD cavities along with endodontic treatment. G₂: Remained unrestored while the other experimental groups were restored with three types of composite resin with or without fiber insertion. G₃: CC resin, G₄: PB fill, G₅: Flowable bulk fill (FB). G₆: Fiber + CC, G₇: Fiber + PB, and G₈: Fiber + FB. FR was tested at crosshead speed of 1 mm/min and recorded in Newton. Data were analyzed using one-way analysis of variance and Tukey's tests at significance level of P < 0.05. Results: G₁ and G2 revealed the highest and the lowest FR, respectively. The mean FR of the testing groups in Newton was as follows: G₁ = 1204.8 ^A, G₂ = 352.1 ^C, G₃ = 579.6 ^BD, G₄ = 596.7 ^BD, G₅ = 624.9 ^BDE, G₆ = 858.3 ^E, G₇ = 529.6 ^CB, and G₈ = 802.5^DE. Different uppercase letters indicate the significant difference between the groups. Conclusion: The effect of fiber insertion on FR depended on the type of composite resin; the highest reinforcing effect was obtained in the CC resin + fiber, followed by bulk-fill flowable + fiber, and flowable bulk (FB)-fill composite resin. The strength of the former was significantly higher than the conventional and PB fill with and without fiber.

Background: Mouthguard (MG) disinfectant sprays are available for maintaining MG hygiene. The effect of these sprays against Streptococcus sobrinus is still unknown. The purpose of this study was to evaluate the antibacterial effect of an MG disinfectant spray against S. sobrinus using the modified ISO 22196 standard. Materials and Methods: In this in vitro study, we used the following treatment groups for antibacterial testing: MG spray-1 (left in spray for 30 s), MG spray-2 (60 s), and control (n = 4). All analyses were performed at a statistically significant level (P = 0.05) using JMP^® 14. Results: The log colony-forming units of the MG spray-2 group were significantly lower than those of the other groups. The antibacterial activity of MG spray-2 against S. sobrinus was >2.1. Conclusion: We confirmed the antibacterial effect of the MG spray against S. sobrinus, and it was influenced by the treatment duration, with the optimum effect at a longer duration.

Background: The margin of crown is a significant area for plaque accumulations. Therefore, the ability of the cement to seal the margin is very important. The aim of the present study was to evaluate the bond (retentive) strength, microleakage, and failure mode of four different types of cements in stainless steel crown (SSC) of primary molar teeth. Materials and Methods: In this experimental study, eighty extracted primary molar teeth were divided into two groups of forty teeth to test the microleakage and bond strength. The crowns were cemented according to the manufacturer guidelines with four cement types including self-cure glass ionomer, resin-modified glass ionomer, polycarboxylate, and resin cements. Stereomicroscope and universal testing machine were used to measure the microleakage and bond strength, respectively. For calculating the surface area of crowns, three-dimensional scanning was used. Furthermore, the failure mode was examined after the bond strength test. The cements surfaces and the tooth–cement interfaces were evaluated using scanning electron microscopy (SEM). The obtained values were analyzed using SPSS-23 software through Shapiro–Wilk and one-way analysis of variance tests. Means, standard deviations, medians, and interquartile ranges were calculated. P < 0.05 was considered as statistically significant in all analyses. Results: Significant differences between microleakage (P = 0.001) and failure mode (P = 0.041) of the four types of cements were obtained. However, the mean bond strengths of the four groups did not differ significantly (P = 0.124). The obtained SEM images confirmed the results of bond strength and microleakage. Conclusion: Resin cement and resin-modified glass ionomer, respectively, showed superior properties and are recommended for use in SSCs of primary molar teeth.

Background: The progressive destruction of nerve cells in nervous system will induce neurodegenerative diseases. Recently, cell-based therapies have attracted the attention of researchers in the treatment of these abnormal conditions. Thus, the aim of this study was to provide a simple and efficient way to differentiate human dental pulp stem cells into neural cell-like to achieve a homogeneous population of these cells for transplantation in neurodegenerative diseases. Materials and Methods: In this basic research, human dental pulp stem cells were isolated and characterized by immunocytochemistry and flow cytometry techniques. In the following, the cells were cultured using hanging drop as three-dimensional (3D) and tissue culture plate as 2D techniques. Subsequently, cultured cells were differentiated into neuron cell-like in the presence of FGF and Sonic hedgehog (SHH) factors. Finally, the percentage of cells expressing Neu N and β tubulin III markers was determined using immunocytochemistry technique. Finally, all data were analyzed using the SPSS software. Results: Flow cytometry and immunocytochemistry results indicated that human dental pulp-derived stem cells were CD90, CD106-positive, but were negative for CD34, CD45 markers (P ≤ 0.001). In addition, the mean percentage of β tubulin positive cells in different groups did not differ significantly from each other (P ≥ 0.05). Nevertheless, the mean percentage of Neu N-positive cells was significantly higher in differentiated cells with embryoid bodies' source, especially in the presence of SHH than other groups (P ≤ 0.05). Conclusion: It is concluded that due to the wide range of SHH functions and the facilitation of intercellular connections in the hanging droop method, it is recommended that the use of hanging drop method and SHH factor can be effective in increasing the efficiency of cell differentiation.

Background: Several techniques such as sand blast, silicoating, and laser irradiation have been introduced for reliable bond between zirconia and resin cement. This study aimed to assess and compare the effect of three types of lasers on the shear bond strength (SBS) of zirconia to resin cement. Materials and Methods: In this in vitro study, 55 zirconia disks (6 mm diameter × 3 mm thickness) were randomly divided into five groups: control (1), sandblast (2), carbon dioxide (CO₂) (3), erbium-doped yttrium aluminum garnet (Er: YAG) (4), and neodymium-doped yttrium aluminum garnet (Nd: YAG) (5) laser irradiation. The surface morphology of one specimen from each group was evaluated by a scanning electron microscope. Zirconia disks were cemented to composite using Panavia F2. SBS test was performed at a crosshead speed of 1 mm/min after 24 h storage in distilled water and thermocycling. The data were analyzed by one-way analysis of variance and post hoc Tukey's HSD tests (α = 0.05). Results: The mean SBS values of the groups such as sandblast, Er: YAG, Nd: YAG, and CO₂ lasers and control were 6.64 MPa, 6.63 MPa, 4.98 MPa, 4.39 MPa, and 2.32 MPa, respectively. No significant difference was observed between sandblast and Er: YAG laser and between Nd: YAG and CO₂ lasers. Conclusion: All lasers increased SBS values of zirconia to resin cement in comparison to the untreated surface. Er: YAG laser was the most effective laser treatment on the bond strength equal to that of sandblast.

Background: The collagen membrane which obtained from bovine pericardium and human skin in Guided Bone Regeneration (GBR) is costly and may even cause transmission of diseases. Replacing conventional collagen membranes with a more easily accessible and cheaper ones will have economic benefits. The aim was to determine the osteogenic effect of collagen-membrane derived from Rutilus kutum swim bladder on rat calvaria. Materials and Methods: The study was experimental. Thirty-six male albino rats of the Wistar strain were included in the study. The 5 mm surgical defects were created on calvarias and filled with allograft bone material and covered by R. kutum swim bladder (Group I), bovine derived pericardial membrane (Group II) and without membrane cover (Group III).The specimen were euthanized after 3, 5 and 8 weeks. The surrounding connective tissue was evaluated in term of osseous formation. Kruskal–Wallis, Univariant analysis of variance, and post hoc tests were used for statistical analysis. The P < 0.05 was considered statistically significant. Results: A significant differences between groups in terms of osseous formation (P = 0.001) was noted. The difference of osseous formation was significantly higher in 5 and 8 weeks than 3 weeks after operation in all groups (P = 0.03 and P = 0.006, respectively). The osseous formation in Group I and II were significantly higher than Group III (P = 0.023 and P = 0.001). Conclusion: The R. kutum swim bladder had osteogenic effect on rat calvaria. R. kutum swim bladder can be a new source in natural derived collagen membrane in GBR.

Background: The aim of the study was to evaluate the effect of 10% alpha-tocopherol and 5% grape seed extract on the microhardness and shear bond strength (SBS) to bleached human dentin. Materials and Methods: This in vitro study was done on 200 extracted premolars which were decoronated and grinded to get flat dentin surface occlusaly. They were divided into four groups: (a) bleaching, (b) bleaching and application of alpha-tocopherol, (c) bleaching and application of grape seed extract, and (d) control. Groups were further subdivided into Subgroups I and II (n = 30) based on storage period before building with composite and were then tested for microhardness and SBS determination. The data thus obtained was subjected to statistical analysis which was performed using ANOVA test and post hoc Tukey's test. The significance for the entire statistical test was predetermined at P < 0.05. Results: The results showed that the microhardness values were minimum in Group A (immediately after bleaching) and maximum in control group. Comparison of data using one-way ANOVA showed that the P value was highly significant (P < 0.001) among the groups. The intergroup comparison of SBS using post hoc Tukey's tests revealed that the P value was significant (P < 0.05) when the comparison was done between the Group A and Group C and Group B with Group D immediately after bleaching. Conclusion: Adverse effects of bleaching can be reversed with the application of 10% alpha-tocopherol and 5% grape seed extract over the dentinal surface microhardness and SBS.

Background: Children undergoing dental rehabilitations by general anesthesia (GA) commonly experience postoperative symptoms such as pain, fever, sore throat, and sleepiness. The aim of the present study was to investigate the specific complications of pediatric dental GA procedure. Materials and Methods: In this observational study sample included 72 children attending GA for dental treatment at the School of Dentistry, Isfahan University of Medical Sciences. Children with American Society of Anesthesiologists physical status I and without any communication or mental health problems were included. GA protocol was standardized. A number of complications were recorded by parents via filling a questionnaire for 2 days postoperatively. Data were analyzed using SPSS statistical software by Wilcoxon and Chi-squared test. P < 0.05 considered as significant level. Results: The most postoperative nonpsychological complications were dental pain (59.7 and 47.2% on days 1 and 2, respectively), followed by inability to eat normal (55.6 and 41.7% on days 1 and 2, respectively). All the patients' nonpsychological complaints had significantly decreased from day one to day two (P < 0.05). The most postoperative psychological complications were Attachments to parents (70.8 and 65.2% on days 1 and 2, respectively) followed by excessive crying (56.9 and 45.8% on days 1 and 2, respectively). All psychological complaints reduced by day two nonsignificantly except excessive crying which decreased significantly after 48 h (P = 0.004). Conclusion: The most postoperative complications after dental rehabilitation under GA were attachments to parents, dental pain, and inability to eat normal and excessive crying, respectively.

Background: The aim of this study was to compare dentinal crack formation in root canal walls following 3 single file systems with continuous rotation under a scanning electron microscope (SEM). Materials and Methods: In this SEM study, seventy mandibular premolars were randomly divided into 5 groups. 3 experimental groups (n = 20) and 2 control groups (n = 5) as follows: Group I: Neolix NiTi file system, Group II: OneShape systems, Group III: OneCurve file system, positive control: conventional Hand File system, negative control: unprepared. After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The sections were inspected in all directions under SEM at × 100 magnification to determine the presence of cracks. The Chi-square test was used to analyze the data. There is a statistically significant difference in the crack formation between the apical third (P = 0.012) and coronal third (P = 0.002) when comparing all the 5 groups. No significant difference is found in the middle third (P = 0.46). P < 0.05 is considered statistically significant. Results: Maximum cracks in the apical third were seen with One Shape file 11 (55%) and in the coronal third with Neolix NiTi 14 (70%). There is a statistically significant difference in the crack formation only in OneCurve when comparing the apical, middle, and coronal third for the individual group (P = 0.042). Conclusion: There was a significant difference in crack formation in apical and coronal third. OneCurve caused the least incidence of cracks when compared to other file systems. OneCurve file system can be a choice for canal preparation over Neolix Niti and OneShape.

Background: Charcoal toothpastes can whiten teeth through abrasion. The purpose of this study was to determine the level of whitening and abrasiveness of charcoal toothpastes in permanent teeth. Materials and Methods: In this in vitro study, 30 premolars were polished, sectioned, mounted, and stored for 5 days in a coffee solution at 37°C. The color and surface profile of the teeth were measured by spectrophotometry and a profilometric device, respectively. The specimens were divided into 3 groups of 10 and were brushed 2000 times (equivalent to 3 times a day for 1.5 months) in a brushing machine using 20 g of each toothpaste (Bencer, Beverly, and Colgate) mixed with 40 ml of distilled water. The color and surface profile were remeasured. Bonferroni test and repeated measures analysis of variance (ANOVA) were used to examine the abrasion. One-way ANOVA was used to assess the whitening. Results: The three toothpastes caused changes in the surface profile (P = 0.0001). ΔE was equal to 3.3 (within the acceptable range) in all groups (95% confidence interval). There was no significant difference in abrasion (P > 0.05) and color change (P = 0.884) among toothpastes. Conclusion: The results of this study showed that all the three used toothpastes have the abrasive and whitening effect on the samples significantly. The differences between the toothpastes were not significant.

Background: Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal diseases which are diagnosed with recurrent and painful ulcers. The possible association between psychological factors and salivary stress related factors in patients with aphthous ulcers has been discussed in various studies. The aim of this study was to evaluate salivary cortisol level, anxiety, and depression in patients with RAS. Materials and Methods: In this case control study, 30 patients with RAS and 30 healthy individuals were enrolled by matching their age and sex. Anxiety and depression were assessed by beck anxiety inventory and beck depression inventory. Unstimulated saliva of both groups were collected and then tested by DiaMetra kit and the ELISA method. Data were analyzed by SPSS using an Independent t-test and Mann–Whitney test. A statistical significance level of <0.05 was considered. Results: The mean salivary cortisol in the case group was 5.35 ng/ml and in the control group was 4.73 ng/ml which was not statistically significant (P > 0.05). There was no significant difference in anxiety and depression level between the two groups (P > 0.05). According to Spearman correlation coefficient, there was an average, negative, and significant correlation between salivary cortisol and anxiety and depression scores in the case group (P < 0.05). Conclusion: This study shows that, although the mean salivary cortisol was slightly higher in patients with aphthous lesions, anxiety, and depression were not possible factors for RAS. There was a moderate, negative correlation between salivary cortisol level and stress and anxiety in patients with RAS.

Background: To evaluate the changes in the micro-hardness and surface roughness of enamel treated with three different concentrations of in-office bleaching agents. Materials and Methods: In this in vitro study, 60 human incisors were divided into two groups (Group A and Group B). To obtain the baseline values, a Vickers tester was used to determine the surface microhardness in Group A, and a Surtronic tester was used for evaluation of surface roughness in Group B. Each group was then further subdivided into three subgroups and subjected to bleaching with Dash (Groups A1 and B1), Pola Office (Groups A2 and B2), and Opalescence Boost (Groups A3 and B3) containing 30%, 35%, and 40% hydrogen peroxide (HP), respectively. Samples were again subjected to testing to obtain the postbleaching values. Pre- and postbleaching data were analyzed by paired t-test. Intergroup comparison was carried out using one-way ANOVA (P ≤ 0.05). Results: A significant decrease in microhardness values was observed following bleaching in all the three groups, with Group A1 showing maximum percentage decrease (2.58%), followed by Group A2 (1.23%) and Group A3 (0.73%). Furthermore, an increase in surface roughness was observed following bleaching, with Group B1 showing maximum percentage increase (14.80%), followed by Group B2 (8.25%) and Group B3 (5.79%). However, there was no significant difference in either microhardness or surface roughness when comparing the postbleaching values among the three bleaching agents. Conclusion: In-office bleaching agents may adversely affect the microhardness and roughness of enamel surface which are not related to the concentration of HP used.

Background: Nickel–titanium (NiTi) instruments have represented a great technological development that enabled endodontists conforming irregular-shaped root canals. Notwithstanding, the repeated use of these instruments may lead to the fracture without any prior visible warning signs. This study aimed to evaluate how multiple clinical instrumentation/sterilization cycles of two NiTi mechanized instruments can affect their microstructural, microchemical, and mechanical characteristics. Materials and Methods: In this observational descriptive study, a total of 140 NiTi instruments, 70 ProTaper Gold^® (PTG) and 70 WaveOne Gold^® (WOG) were analyzed. For each brand system, instruments were evaluated in the as-received condition (n = 10) and after one (n = 20), two (n = 20), and three (n = 20) instrumentation/sterilization cycles. Intraoperative instrumentation parameters were recorded for all used instruments. Afterward, the files were examined using scanning electron microscopy and energy-dispersive X-ray microanalysis. All of the instruments were tensile-fatigue tested until rupture in order to calculate the mechanical tensile strength and the maximum elongation percentage for the samples. Statistical analysis was completed using Chi-square, Kruskal–Wallis H-, or Mann–Whitney U-tests with a statistical significance set at P < 0.05. Results: Significant increasing changes in surface topography (P < 0.05, Chi-square test) and chemical composition (P < 0.05, Kruskal–Wallis H-test) in both brand systems through instrumentation/sterilization cycles were detected. In addition, values of mechanical tensile strength and maximum elongation percentage increased significantly through instrumentation/sterilization cycles in the PTG group, whereas only the median values of mechanical tensile strength increased significantly in the WOG group (all P < 0.01, Kruskal–Wallis H-test). Conclusion: Although multiple instrumentation/sterilization cycles may render NiTi instruments more flexible and fatigue resistant, the significant changes detected in their surface topography and chemical composition should preclude their repeated clinical use in the routine endodontic practice as prevention for breakage.

The most common orthognathic surgery approach consists of three steps: presurgical orthodontic treatment, surgery, and postsurgical orthodontic treatment. Despite its advantages, this technique has some disadvantages, too, including a long treatment period, problems in mastication and articulation, temporary worsening of the patient's appearance, and psychological problems for the patient. The introduction of the surgery-first orthognathic approach has been an attempt to overcome these problems. In this article, we wish to provide a comprehensive overview on this approach. In this approach, which consists of surgery without orthodontic preparation and a short period of orthodontic treatment after it, the overall duration of treatment decreases and the patient's appearance improves. The skeletal anchorage, placed at the time of surgery, can be used to facilitate tooth movements after surgery. Despite the advantages of this technique, it is associated with some limitations; in particular, occlusion cannot have a guiding role during surgery. Therefore, correct diagnosis, prediction of the outcomes, and simulating correction with the model setup are of crucial importance. The surgeon's knowledge and expertise have a significant role in this respect.

Background: Periostin is a protein, which is essential for periodontal tissue integrity, development and maturity. The aim of this study was to evaluate the role of gingival crevicular fluid (GCF) periostin levels in the association between coronary heart disease (CHD) and chronic periodontitis (CP). Materials and Methods: This matched case–control study was conducted on 116 participants. The participants were matched for age, gender, and body mass index and divided into four groups as follows: (1) 29 patients with CHD and sever CP (CHD-CP), (2) 29 patients with CHD and without CP (CHD-H), (3) 29 patients without CHD and with sever CP (H-CP), and (4) 29 healthy participants (H-H). The GCF periostin was collected and evaluated using the enzyme-linked immunosorbent assay (ELASA). Finally, the data were analyzed by analysis of variance using the stata software. Significance was assigned at P < 0.05. Results: The results showed that there was a significant difference in the GCF periostin levels in the four groups (P < 0.05). Moreover, according to the results of the Bonferroni's test, differences in the mean periostin levels were significant (P < 0.001) between CHD-CP and CHD-H, CHD-CP and H-CP, CHD-CP and H-H, CHD-H and H-H, and also between H-CP and H-H. Conclusion: The periostin levels reduced in the CHD patients, especially in the CHD-CP group. The findings reveal a probable role of periostin in the association between CHD and CP.

Background: To maintain the integrity of the interface between root canal filling and radicular dentin an ideal endodontic biomaterial should have good adhesion. This study was aimed to evaluate the bond strength and tubular penetration of modified bioceramic materials by indirect ultrasonic activation. Materials and Methods: In the present in vitro experimental study, 120 coronal root slices of 2 mm were prepared from mandibular premolars and randomly divided into six groups (n = 20) in accordance to placement techniques: Group I: Nano Biodentine-manual, Group II: CaCl₂ modified ProRootMTA-manual (MM), Group III: Biodentine-manual, Group IV: Nano Biodentine: Ultrasonic, Group V: CaCl₂ modified ProRootMTA-ultrasonic, and Group VI: Biodentine-ultrasonic (BDU). The samples were kept in humidifier for 4 days at 37°C and push out bond strength, sealer penetration were evaluated using an universal testing machine and confocal laser scanning microscope respectively. Data were subjected to statistical analysis using SPSS software by using One-way ANOVA for overall significance and Tukey's multiple post hoc test for intergroup comparison (P < 0.05). Results: Highest push out bond strength and greater tubular penetration were observed with Group VI (BDU), while the lowest bond strength and tubular penetration were associated with Group II (MM). Conclusion: Within the limitations of current study it was observed that Biodentine with indirect ultrasonic activation has resulted in highest pushout bond strength among all the study groups.

Background: It was documented that the clinical outcomes of mechanical periodontal treatment can fluctuate not merely concerning patients but equally among various tooth sites in the subject. This trial evaluates the clinical parameters related with the patient, tooth, and site that generate more changes in clinical attachment level (CAL) gain and probing depth (PD) reduction, using moxifloxacin (MOX) versus amoxicillin plus metronidazole (AMOX + ME) as adjuncts to scaling and root planing (SRP), in comparison to SRP only, post-therapy in generalized aggressive periodontitis (GAgP). Materials and Methods: The analysis of this clinical trial included 6012 tooth sites at 1002 teeth in 36 patients; they were randomly assigned to three protocols: Systemically intake of MOX or AMOX + ME plus SRP, or SRP + placebo for 7 days. The clinical effect of the patient, tooth, and site characteristics, in terms of CAL gain and PD reduction, was explored using a multilevel linear model. P < 0.05 was statistically significant. Results: Following 6 months of treatment, the differences between the groups were statistically significant, favoring the MOX and AMOX + ME protocols (P < 0.0001). Moreover, the multilevel model showed that adjunctive MOX, AMOX + ME, non-molar, and interproximal sites were the features that contribute significantly to CAL improvement, and PD decreases in GAgP (P ≤ 0.001 for all). Conclusion: The most relevant characteristics for the changes in CAL increase and PD diminution, after adjunctive antimicrobials, were ascribable to the features related to the tooth. MOX and AMOX + ME, non-multi-radicular-tooth, and interdental sites indicated superior clinical gains at the tooth and site levels in GAgP.

Background: Dental implants are widely accepted substitutes for replacing missing teeth. Many factors, including the use of specific drugs such as proton-pump inhibitors (PPIs) (omeprazole), can affect the success of dental implantations. The aim of this study was to investigate the relationship between the use of omeprazole and osseointegration of dental implants. Materials and Methods: This experimental animal study was performed on eight native male dogs weighted 11–13 kg and aged 16–20 months. The dogs were divided into two groups (receivers and nonreceivers of omeprazole). After extraction of mandibular teeth, treatment was started randomly with the administration of omeprazole and saline. After a 2-month recovery period, six titanium implants were placed in the jaws of all dogs and the administration of omeprazole was continued for 2 weeks. After 4 and 12 weeks, the dogs were anesthetized and dental implants with their bone marrow were removed. The samples were examined histomorphometrically to determine osseointegration. Data were analyzed with two-way ANOVA test for 95% confidence interval. The P value was set at 0.05. Results: In the microscopic examination of the samples in week 4, the levels of bone–implant contact (BIC) in the study group were significantly lower than the control group (46.37 vs. 64.37%). In 12 weeks, BIC was significantly lower than that of the control group (67.33 vs. 82.00%). The type of bone formed in week 4 in both the groups was more woven, and in the 12th week, it was mostly lamellar. Conclusion: Systemic administration of PPIs may interfere with osseointegration of dental implants.

Materials and Methods: In this descriptive study, a total of 768 radiographs of mandibular first molars, 384 for males and 384 for females, taken at a private radiology center in Isfahan, were assessed for the presence of middle mesial canal based on the gender of the patients. All samples had been prepared by one CBCT machine. The images were evaluated by endodontists and radiologists. Then, the morphology of first molar mesial root canals was assessed by Vertucci classification, and the obtained results were analyzed by SPSS software using a Chi-square test. The comparison was considered statistically significant at P < 0.05. Results: Twenty-four samples (3.13%) had a middle mesial canal. The prevalence rates of the middle mesial canal in the females and males were found to be 9 and 15 (2.35% vs. 3.92%), respectively, indicating no statistically significant difference (P = 0.21). Of 24 teeth with middle mesial canal, 17 samples (70.8%) were of Type XII and 7 samples (29.2%) were of Type VIII. There was no statistically significant difference between genders with regard to the prevalence of different types of middle mesial canals (P = 0.19). Conclusion: The prevalence of the middle mesial canal was rather low in this study, and it is necessary to detect additional canals in the patients under root canal treatment.

Background: Since the symptoms of child abuse and neglect often manifest in the orofacial region, the dental team has a key role in identifying children subjected to abuse. This study was aimed to explore the prevalence of failure to take history as a barrier to reporting child abuse by dentist around the world. Materials and Methods: In this systematic review and meta-analysis, PubMed, Embase, Scopus, Google Scholar, ProQuest, Cochrane, and ISI databases were searched for the cross-sectional articles in English languages on barriers to reporting child abuse and lack of knowledge about referral procedures by dentists since 1985 using Medical Subject Headings (MeSH). The full-texts of all included articles were obtained and assessed for quality according to Newcastle–Ottawa Scale adapted for cross-sectional studies. The qualified articles were then studied thoroughly and results were extracted. Data were analyzed by Comprehensive Meta-Analysis software using meta-analysis and random effects model. Heterogeneity was determined by Q-test and I-square index. Results: A total of 17 articles were included in the meta-analysis. The prevalence of lack of knowledge about referral procedures as a barrier was determined according to the meta-analysis of the number of relevant articles and was (55%, confidence interval: 0.48, 0.62). Conclusion: The analysis of various studies revealed lack of information about referral procedures as an important barrier to report child abuse by dentists.

Background: Appropriate cleaning and shaping and three-dimensional obturation of the root canal system lead to a successful endodontic treatment. To achieve this, complete knowledge of the internal anatomy of root canals is necessary. Therefore, this study evaluated the number and shape of mandibular premolar roots and canals and classified their Vertucci classification using cone-beam computed tomography (CBCT) images of an Iranian sample population. Materials and Methods: This in vivo study was performed on CBCT images of patients aged 20–70 years who had attended a dental radiology center in Isfahan. CBCT images were examined in coronal, sagittal, and especially axial dimensions. Descriptive statistics were calculated. Groups were compared using the Chi-square of the Statistical Package for the Social Sciences. The level of significance was predetermined as 0.05. Results: In both first and second premolars, the most common classes were Type I followed by Type V. The Chi-square did not show significant differences between males and females in terms of Vertucci classes in the first (P = 0.305) or second premolar (P = 0.315). Conclusion: Since a thorough knowledge of root canal anatomy is necessary for successful root canal treatment and almost one out of ten mandibular premolars has additional canal in their root canal system, accurate evaluating of preoperative radiographs, taking CBCT images if necessary, and probing the root canal system with fine and precurved files should be done to negotiate the entire canal system.

Background: Ferritin is an acute-phase protein that is increased in inflammatory diseases. Melatonin has been studied due to its antioxidant effects and the elimination of free radicals. The aim of this study was to evaluate the effect of melatonin supplement as an adjunct to routine periodontal treatment on serum ferritin levels in patients with periodontitis. Materials and Methods: Forty patients with chronic periodontitis were included in this randomized controlled clinical trial study. Twenty patients received nonsurgical periodontal treatment and twenty patients received nonsurgical periodontal treatment with adjunctive use of melatonin. Serum ferritin concentrations and periodontal parameters were recorded at baseline and 3 months after periodontal therapy. Serum ferritin level and periodontal parameters comparison at baseline and 3 months after periodontal treatment was done by Wilcoxon signed-rank test and paired sample t-test, respectively. Differences between test and control groups were evaluated by Mann–Whitney U-test for ferritin level and independent t-test for periodontal parameters, and a P ≤ 0.05 was considered statistically significant. Results: Serum ferritin level decreased in both the control and test group in 3 months follow-up compared to baseline (P < 0.001). The reduction in ferritin levels in the test group was more than the control group, but this difference was not statistically significant (P = 0.414). Improvement in periodontal parameters were not significant between two groups (P = 0.489), but improvement rates in the test group were more than control. Conclusion: Melatonin, as an adjunct to periodontal therapy, showed additional benefits in the reduction of serum ferritin levels and improvement of periodontal parameters.

Background: Since there is no comparison between the effects of Sabbagh Universal Spring 2 (SUS2) appliance on Class II division 1 (div 1) versus Class II division 2 (div 2) patients, this preliminary study was conducted to comparatively assess, for the first time, the effects of SUS2 on 34 cephalometric indices in Class II/1 versus Class II/2 patients. Materials and Methods: This before–after clinical trial was conducted on 75 observations of 25 patients with Class II malocclusion, of whom 12 (9 females and 3 males) had Class II div 1 and 13 (11 females and 2 males) had Class II div 2 malocclusion diagnosed by clinical examination and cephalometric assessment. The growth level of all patients had to be CS3 according to the cervical vertebral maturation index. Lateral cephalographs were obtained before treatment (T0) and the patients underwent fixed orthodontic treatment. Lateral cephalographs were taken again (T1) and the patients received SUS2 functional appliance for 6 months. A final lateral cephalograph (T2) was then obtained. Thirty-four dentoskeletal indices were measured on lateral cephalographs, and changes in indices over time were determined and compared using repeated-measures analysis of variance, post hoc test, and t-test (α =0.05). Results: Within-group comparisons showed significant changes over time in SNB, sella nasion (SN)/occlusal plane, ANB, articular (Ar)-pogonion (Pog), L1-NB, condylion (Co)-gnathion , S-Ar/Ar-G, B-RL1, L1/nasion-point B (NB), U6-RL2, incisor mandibular plane angle, overjet, overbite, U1-RL1, and L1-RL2 (P < 0.05). The two groups were significantly different in terms of changes occurred to overjet, interincisal angle, U1/RL1, L1-NB, U1-NA, U1/NA, the Jarabak ratio, A-RL1, U1/SN, Pog-NB, and Co-A (P < 0.05). Conclusion: The SUS2 showed therapeutic efficacy for both Class II div 1 and 2 patients although it more commonly caused dentoalveolar rather than skeletal changes. Our study showed no considerable difference between the two groups after using this appliance, and the difference in the Jarabak ratio indicated better long-term growth pattern of div 2 patients and its conformity with camouflage treatments (mild or moderate Class II).

Background: Conventional drug mixtures used in regenerative endodontic procedures have a toxic effect and no consensus has been reached about their best composition and concentration. Therefore, the aim of this study was to determine minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum biofilm inhibitory concentration (MBIC) of the antimicrobial preparations and to compare their antimicrobial efficacy on bovine dentin infected by Enterococcus faecalis. Materials and Methods: For this original ex vivo investigation, prepared concentrations (MIC, MBC, and MBIC) of triple antibiotic paste (TAP), double antibiotic paste (DAP), modified triple antibiotic paste (MTAP)-1, MTAP2, co-amoxiclav, and calcium hydroxide (CH) were added to the prepared bovine dentin blocks (which incubated in E. faecalis suspension previously) and incubated for 3 days. The samples were subsequently prepared for culture and CFU counts. Statistical analysis of data was carried out using one-way analysis of variance and post hoc tests. The statistical power was set at P < 0.05. Results: All medicament groups significantly showed an antimicrobial efficacy compared with negative control (without antibiotic) (P < 0.001). TAP, DAP, co-amoxiclav, and CH (at its MBC value) were significantly capable of eliminating E. faecalis biofilm and showed no significant difference in comparison with positive control (complete biofilm removal) (P < 0.05). Conclusion: TAP, DAP, co-amoxiclav, and CH (at its MBC value) could effectively eliminate biofilm bacteria on the dentin surface. Antimicrobial efficacy of other medicaments containing cefaclor or clindamycin was limited.

Background: Odontogenic cysts and tumors exhibit varying degrees of aggressiveness in their biological behavior. Odontogenic keratocyst (OKC), dentigerous cyst (DC), ameloblastoma are most common odontogenic cysts and tumors to occur in the oral cavity. Myofibroblasts (MFs) in the connective tissue stroma participate in the matrix degradation process by secreting matrix metalloproteinase 2, transforming growth factor beta1 and may contribute to variation in their biological behavior. Its activity is identified by alpha-smooth muscle actin (α-SMA) marker. With this background, the present study aims to evaluate the frequency of MFs using α-SMA to determine the biological behavior of OKC, DC, and different clinical variants of ameloblastoma. Materials and Methods: A retrospective study was carried out with total of 60 samples which include 10 cases each of OKC, DC, 30 cases of different clinical variants of ameloblastomas and 10 normal mucosa taken as controls. All are stained immunohistochemically using α-SMA and were analyzed for the same. Comparison between more than 2 groups done by one way analysis of variance test with the level of significance of P ≤ 0.0001, i.e., <0.05. Results: Statistically significant difference in the mean number of MFs observed between certain groups, with higher mean number in solid ameloblastoma (SA) (32.45) followed by OKC (28.79), unicystic ameloblastoma (24.53), desmoplastic ameloblastoma (7.44), and DC (1.72). Conclusion: Higher frequency of MFs noticed in SA, OKC which are key cells for connective tissue remodeling by interacting with epithelial cells and other connective tissue cells to facilitate progression of cysts and tumors thereby contributing to their biological behavior.

Background: Infraorbital nerve injury often occurs due to zygomatic complex fracture. There is no standard protocol to restore the sensory and motor function of the nerve after injury. Some medications are used to improve nerve function. This histopathological animal study aimed to assess the neurotrophic efficacy of exenatide, ozone, and methyl prednisolone for injured infraorbital nerve. Materials and Methods: In this animal study, 60 rats were randomly divided into five groups (n = 12) of control, saline, methyl prednisolone, exenatide, and ozone. Under general anesthesia, a unilateral infraorbital incision was made, and the nerve was compressed with a hemostat for 5 s. Depending on the study group, the rats received the designated medications. All rats were sacrificed after 14 days, and the nerve recovery was evaluated by observing the slides prepared from the area under a light microscope using histological and immunohistochemical parameters. Data were analyzed using Chi-square test and Tukey's least significant difference test (P < 0.05). Results: No inflammation in the peripheral tissue had a significantly higher frequency in the methyl prednisolone group (P < 0.05). Degeneration, intracellular inflammatory infiltrate, muscle injury, fibrosis around the nerve, granulation tissue, vascular proliferation, and infiltration of inflammatory cells around the nerve were more commonly absent in the exenatide group (P < 0.05). Conclusion: Exenatide showed superior efficacy for the recovery of infraorbital nerve function after injury. Thus, it may be beneficial for postoperative care following infraorbital nerve injury.

The aim of the present study was to describe two clinical cases showing postoperative pain associated with the use of plastic carrier obturation system and apical bone fenestration. The patients were treated by surgical access and apicoectomy through a modern technique (using magnification and microsurgical approach), thus removing the direct contact between obturation material and submucosal connective tissue. The surgical interventions were carried on without the occurrence of any complication. Postsurgical adverse sequelae were negligible. After few weeks from the surgery, all symptoms disappeared. Radiographic healing was observed after 48 months. The presence of apical bone fenestration could be the cause of persistent pain after root canal treatment. The contact between plastic carrier and submucosal connective tissue could be the direct cause of spontaneous pain even in absence of periapical infection. Since the clinical diagnosis could be difficult, the use of tridimensional radiology could be justified. Surgical approach, by the removal of the contact between the carrier and connective tissues, can be considered a viable option to treat these particular affections.

Background: There are many treatment protocols for relieving pain and accelerating oral ulcer healing. The purpose was to evaluate the anti-inflammatory and antimicrobial effect of silver nanoparticle (AgNP) gel on oral ulcers compared with the traditional treatment in animal model. Materials and Methods: In this experimental study, 72 adult male rats were randomly allocated into four groups, after ulcer induction: control (receive no treatment), placebo (placebo gel was applied on ulcers once daily), triamcinolone (ulcers were treated with triamcinolone paste once daily), and AgNPs (ulcers were treated with AgNP gel once daily). The animals were sacrificed at three successive periods of 3, 7, and 14 days after ulcer induction. Histopathological scores of re-epithelialization and degree of inflammation were assessed. The wound size was measured clinically. For parametric data, the analysis of variance, and for ordinal histopathological data, the Kruskal–Wallis test using SPSS was done. A P < 0.05 was considered statically significant. Results: Control and placebo groups had no case of complete healing. Improvement of wound size by triamcinolone paste was not significant in different days but showed significant differences in degree of inflammation (P < 0.001) and re-epithelialization (P = 0.012). Reduction of wound size by AgNPs gel had significant difference at 14^th day (P < 0.001); further, by this gel, significant differences in degree of inflammation and re-epithelialization were seen in long-term medication. Conclusion: AgNP gel could be effective in oral ulcer healing clinically and histopathologically. Although this gel showed delayed effect, it had better healing effect according to the cases with complete healing. Hence, the application of AgNP oral gel can be considered as an alternative approach for oral ulcers.

Background: The present study was performed to evaluate the effect of three types of mouthwash (orthokin, oral B and chlorhexidine [CHX]) on releasing of aluminum (Al), Titanium (Ti) and Vanadium (V) ions from titanium mini-implants (TMIs). Materials and Methods: In this in vitro, experimental study, a total of 40 TMIs were divided equally into four groups (10 TMI in each group) and then were immersed into Orthokin, Oral B, CHX, and artificial saliva, as a control. The experiments were performed for 21 days as following groups 1–7 days, 8–14 days, and 15–21 days. The inductively coupled plasma-optical emission spectrometry method was used to assess releasing metal ions after immersion in the storage media. In addition, before and after each experiment, the corrosion of TMIs was assessed using a scanning electron microscope (SEM). All results were analyzed using Kruskal–Wallis, followed by Bonferroni-adjusted Mann–Whitney U-test at 0.05 level of significance. Results: Our data showed that the maximum concentration of released Al was in the 1^st week of exposure to Orthokin and Oral B (202.3 ± 68.5 and 72.3 ± 15.2 μg/L, respectively). Oral B exposure of TMI also caused to releasing of Ti to 128.1 ± 42.5, 54 ± 19.4 and 22 ± 6 μg/L for 1–7 days and 8–14 days and 15–21 days, respectively. Orthokin and CHX also induced the release of Ti more than artificial saliva (P < 0.05). In addition, there was no significant statistical difference between any types of mouthwashes and artificial saliva in releasing V. The results of SEM images also confirmed the corrosion effects of mouthwashes. Conclusion: The factors of exposure time and mouthwash type influenced the pattern of releasing Al and Ti as well as corrosion level.

Background: This study aimed to assess the effect of citric acid, as a weak acid commonly used in food industry, on elastomeric chain force decay. Materials and Methods: In this in vitro, experimental study, sixty elastomeric chains from two commercial brands of American Orthodontics and Ortho Technology (n = 30) were cut into five-piece segments. Elastomeric chains of each brand were randomly divided into two groups of control (artificial saliva) and citric acid. All elastomeric chains were incubated in artificial saliva at 37°C. Experimental samples were immersed in 10 mL of citric acid for 90 s daily and were then transferred back to the artificial saliva. The elastomeric chain force was measured at baseline (before the experiment), 1 day, 1 week, 2 weeks, and 3 weeks using an electromechanical universal testing machine. Data were analyzed using t-test, Kruskal–Wallis test, and Mann–Whitney U-test at 0.05 level of significance. Results: The elastomeric chain force gradually degraded over time. The difference in this respect was not significant at 2 and 3 weeks in any group (P > 0.05). On initiation of the experiment, the force in the citric acid group experienced a greater decay than that in the control group; the difference between the citric acid and control groups in both the brands was significant at all time points until the end of the 3^rd week (P < 0.05). The difference between the American Orthodontics and Ortho Technology brands in the control and citric acid groups was significant at all time points (P < 0.001). Conclusion: Elastomeric chains in both the citric acid and artificial saliva groups experienced force decay over time. Force decay was greater in the citric acid group. Thus, citric acid can effectively decrease the elastomeric chain force. The Ortho Technology chain force was higher than that of American Orthodontics in both the groups at all time points.

Background: The flexural strength (FS) of a denture base material is of great concern, and many approaches have been used to strengthen the denture acrylic resins. The present study aimed to evaluate the effect of high-performance polymer (BioHPP) and metal mesh reinforcement on the FS of a heat-cured poly methyl methacrylate (PMMA) acrylic resin. Materials and Methods: This experimental study was done on 30 rectangular specimens (64 mm × 13 mm × 3 mm) of a heat-cured PMMA resin. The specimens were divided into three groups (n = 10) to be reinforced with either metal mesh or BioHPP mesh; one group was left nonreinforced, serving as the control group. The FS of specimens was assessed through a 3-point bending test by using a universal testing machine at a crosshead speed of 2 mm/min. Kruskal–Wallis H and Dunn's post hoc tests were used to compare the FS among the groups (alpha = 0.05). Results: The FS in the metal-reinforced group was statistically significantly higher than the two other groups (P < 0.001). However, the FS of the BioHPP-reinforced samples was not statistically significantly higher than the nonreinforced ones (P = 0.614). Conclusion: Reinforcing the PMMA with metal mesh significantly enhances its FS while BioHPP has no significant effect on the PMMA FS.

Based on our collective experiences with gap management around immediate dental implants, we have proposed a classification of gap type based on the location in relation to implant periphery. Seven types are proposed, and all but one type should heal without gap grafting provided that flap-less surgery and atraumatic extraction have been achieved. The exception is our Type II gap where the implant has been placed too far buccally leaving a gap only on the lingual/palatal. In this case, the lingual/palatal gap need not be grafted, but the buccal aspect of the implant should best to augmented to avoid the complications.

Tooth nonvitality is one of the frequently seen consequences of dental trauma that causes the arrest of root development. Amniotic membrane has received a lot of attention for its use in transplantation and regeneration procedures. This article reports a unique and novel case of successful regenerative endodontic procedure done using amniotic membrane in a traumatized immature right maxillary central incisor of an 8-year-old girl. The clinical and radiographic evaluation done during the recall visits at 1, 3, 6, 9 and 12 months showed a progressive root growth with apical closure.

Background: Association of cuspid impaction with adjacent lateral incisor anomalies is under controversy. The aim of this study was to investigate the correlation between maxillary cuspid impaction with dental anomalies. Material and Methods: In this in vitro experimental study, the material consisted of pretreatment dental records of 102 patients with at least one palatally or buccally displaced impacted permanent cuspid (palatal and buccal impaction groups). They were matched with a comparison control group of 102 patients having normally erupted maxillary cuspids. Available space, mesiodistal dimensions of teeth, and morphologic parameters of lateral incisors were measured using the digital caliper. Comparison of mean values of lateral incisors anomalies and severity of crowding between different groups were performed using the one-way ANOVA test, and the analysis of associations between position of the impaction and anomaly of the lateral incisors and severity of crowding was performed using the Chi-square test. P < 0.05 was considered statistically significant. Results: There was no statistically significant difference in the arch length–tooth size discrepancy between the cuspid impaction groups and control group. The impaction group (buccal or palatal) presented statistically significant differences in terms of anomalies of maxillary lateral incisor compared to the control group. Peg-shaped lateral incisor was related to buccal cuspid impaction and microdontia had relationship with palatal cuspid impaction. Conclusion: There is the relationship between cuspid impaction and adjacent lateral incisor abnormality, but no difference was observed between buccal and palatal cuspid impactions. Crowding revealed no relationship with cuspid impaction (buccal or palatal) in this study.

Background: Although dental care attendance during pregnancy has been recommended by guidelines and institutions, the demand for dental services is still low among pregnant women. The aim of this study was to examine the prevalence of not receipt dental care and also determinants of that during pregnancy. Materials and Methods: This population-based study was conducted on 4071 mothers in 10 provinces of Iran, during 2014–2015. We calculated the prevalence of not receipt of dental care, and reasons for nonreceipt of care. We used logistic regression to estimate odds of nonreceipt of care by demographics variables. In the analyses, the level of statistical significance was set at P < 0.05. Results: Overall, 54.70% of women had no dental visit during pregnancy. In mothers who had a history of stillbirth, neonatal death and live birth, the prevalence of not receipt dental care during pregnancy were 54.56%, 48.92%, and 58.76%, respectively. The logistic regression analyses showed that parity second-to-fourth birth than first birth (odds ratio [OR] 1.37 confidence interval [CI] 95% 1.17–1.59, residence in rural (OR 1.68 CI 95% 1.45–1.95), and not intended pregnancy (OR 1.32 CI 95% 1.03–1.68) associated with not received dental care during pregnancy. Conclusion: Most pregnant women in this study received insufficient dental care. The need for dental care during pregnancy must be promoted widely among women of reproductive age, and family barriers to dental care should be addressed.

Background: Despite the many advantages of simplified adhesive systems, there are concerns about the durability of the adhesive layer over time. The aim was to investigate the effects of various aging methods and double application of an adhesive layer on the bond strength of the universal adhesive system using etch-and-rinse (ER) and self-etch (SE) strategies. Materials and Methods: In this in vitro study, the occlusal enamel of 120 extracted, intact human third molars was removed to expose the dentin. Then, the samples were randomly divided into four groups of thirty according to All-Bond Universal (ABU) adhesive application strategy (ER and SE) and the number of adhesive layers (1 or 2). Then, each group was subdivided into three subgroups of ten according to aging method (control, thermal cycling, and 10% sodium hypochlorite [NaOCl]). The shear bond strength was measured at the strain rate of 0.5 mm/min. Data were analyzed using three-way ANOVA and Tukey's post hoc tests (P < 0.05). Results: The effect of adhesive application strategy (P < 0.001) and aging method (P < 0.001) on the bond strength was statistically significant, but the effect of the double application was not statistically significant (P > 0.05). In addition, the interactive effect of adhesive application strategy–aging method was significant (P = 0.005). Conclusion: Using ABU with ER strategy leads to higher dentin bond strength compared to the SE method in the control and thermal cycling groups. However, no significant differences were observed between ER and SE strategies after aging with the NaOCl. Furthermore, the double application might not have any effect on the bond strength and durability.

Background: Soft skills are the key indicators of success and quality of performance in various professions, including the dental profession. The skills are the main tools for enhancing the quality of technical work in Dentistry. Hence, the aim of this study was to identify and prioritize the soft skills in dental profession. Materials and Methods: The study employed a mixed methods research. In the qualitative phase, the dental skills were identified using a semi-structured interview with faculty members and dental students. In the quantitative phase, the soft skills were prioritized with Analytical Hierarchical Process (AHP). The data analysis was using Expert Choice software. Results: The results showed that the dental profession to improve the quality of performance needs to 29 soft skills in six categories. In professional ethics, work ethics (with weight of 0.212) and responsibility (0.188); in artistic skills, handicrafts (0.616); in cognitive skills, decision-making ability (0.290) and spatial thinking (0.249); in communication skills, verbal/nonverbal communication and listening (0.266), and patience (0.240); in individual characteristics, stress management (0.381) and self-esteem (0.260); and finally, in management skills, time management (0.481) are among the most important soft skills in dental profession. Conclusion: Identify and prioritize the soft skills can help to improve the quality of performance the dental profession. Therefore, it is recommended to integrate these skills into the dentistry curriculum. Moreover, by increasing the number of studies the essential backgrounds for developing soft skills in dentistry education will be provided.

The use of computer-aided design/computer-aided manufacturing technology simplifies the laboratory and clinical steps for the fabrication of implant prostheses. It also reduces additional costs for the prosthetic components and technical procedures. This article describes a modified impression technique using an impression metal jig to enhance the accuracy of final impression and also to eliminate the need for the try-in of resin pattern of the milled bar.

Background: This study aimed to compare the effect of four temporary luting agents on preventing the coronal microleakage of teeth restored with custom cast post and core. Materials and Methods: In this in vitro original study, after removing 9 mm of gutta percha from root canals of 32 single-canaled premolars, the acrylic resin patterns of the post and core were fabricated. Patterns were cast with Ni-Cr metal alloy and then cemented with glass ionomer. Using self-curing acrylic resin, provisional restorations were made. Then, teeth were randomly allocated to four groups for each temporary cement including zinc oxide eugenol (Temp Bond), zinc oxide noneugenol (Temp Bond NE), noneugenol resin-based temporary luting agent (Temp Bond Clear), and noneugenol urethane methacrylate polymer-based temporary luting agent (Dento temp). Teeth were subjected to thermocycling, immersed in silver nitrate for 6 h and then sectioned. The amount of dye penetration in the margin of provisional crown and into the coronal part of the root canals was measured using a stereomicroscope. Data were analyzed using the Kruskal–Wallis and Dunn tests with significance level of 0.05. Results: All the luting agents showed some degree of microleakage (Group 1 showed the most microleakage). According to the pair comparison between the groups, Group 1 revealed a significant difference with others (P < 0.05). Furthermore, Group 2 showed more microleakage as compared to Group 4 (P = 0.037). Conclusion: Temp Bond showed the highest microleakage as compared to other luting agents. Furthermore, Temp Bond NE revealed a weaker sealability as compared to Dento temp.

Background: The aim of this study was to compare the effect of chlorhexidine- and Persica-containing mouthrinses on the surface characterization of orthodontic appliance and friction between the orthodontic stainless steel wires and brackets. Materials and Methods: In this randomized controlled trial, 75 orthodontic patients (aged 13–30) were allocated (n = 25) into two experimental groups (prescribed by Persica- or chlorhexidine-containing mouthrinse) and one control group (no prescription). The ovoid stainless steel archwires were placed, and the maxillary first premolar stainless steel edgewise brackets were ligated to wires by elastomeric rings. The patients were recalled after 2 weeks, and then, the archwires were removed and replaced. The surface analysis of archwires and brackets was evaluated using scanning electron microscopy and atomic force microscopy. The frictional forces between the archwires and brackets were measured using a universal testing machine. The data for surface roughness were analyzed by the nonparametric Kruskal–Wallis and Mann–Whitney tests. The frictional forces data were analyzed using a two-way analysis of variance and Tukey's post hoc test using SPSS software. The level of significance was P < 0.05. Results: The retrieved brackets showed minor changes in their surface topography. The surface roughness of archwires after the intervention was significantly greater for the chlorhexidine than that of Persica (P < 0.05). The friction force between the archwires and brackets was also significantly higher for the chlorhexidine than that of Persica (P < 0.05). Conclusion: The Persica-containing mouthrinse from the biomechanical and biochemical standpoints may be a better option for oral hygiene in orthodontic patients compared with the chlorhexidine.

Background: Laser therapy, along with the use of fluoridated compounds is a novel technique suggested for caries prevention. Casein phosphopeptide amorphous calcium phosphate (CPP-ACP) is another product suggested for this purpose. This study compared the effect of CPP-ACP and fluoride with/without Erbium, chromium-doped yttrium, scandium, gallium, and garnet laser irradiation on enamel microhardness of permanent teeth. Materials and Methods: This in vitro experimental study evaluated 35 extracted third molars. The teeth were decoronated, and the crowns were split into buccal and lingual halves. The samples were randomly divided into seven groups (n = 10) of GC Tooth Mousse, MI Paste Plus, laser, fluoride varnish, laser + GC Tooth Mousse, laser + MI Paste Plus, and laser + fluoride varnish. The baseline microhardness was measured before the intervention. After the intervention, the samples were kept in artificial saliva for 1 h and were then immersed in the demineralizing solution for 3 h followed by 21 h of immersion in the remineralizing solution for a total period of 12 days. Finally, the teeth were kept in the remineralizing solution for 2 more days. The secondary microhardness of the teeth was then measured. Data were analyzed using the Shapiro–Wilk test, two-way ANOVA, and Tukey's Honestly Significant Difference test. Results: The fluoride varnish (14.31%) and laser + fluoride varnish (18.79%) groups experienced minimum reduction in microhardness, while the GC Tooth Mousse group experienced maximum reduction in microhardness (91.64%) (P < 0.001). Laser irradiation before the application of remineralizing agents increased the microhardness only in laser + GC Tooth Mousse group (P < 0.001). Conclusion: Fluoride varnish increased the enamel microhardness, while GC Tooth Mousse had no such effect. Laser therapy before the application of remineralizing agents did not significantly enhance enamel resistance to demineralization.

Background: This study aimed to evaluate the use of artificial teeth for endodontic training for dental students. Materials and Methods: The following aspects of the artificial teeth were approved by the endodontists in Isfahan University of Medical Science: internal and external anatomy; coronal pulp chambers regarding their size, shape, and canal path; the root canals regarding their size, shape, and position; filling the pulp chamber and root canals by considering the texture, quantity, color, and ease of handling; and resin hardness and visualization of the radiographic image. Results: The results showed favorable opinions regarding the internal and external anatomy, coronal pulp chamber, root canal (s), handling, and radiographic imaging. The contents of the pulp space and hardness of the teeth were satisfactory. Conclusion: The artificial teeth tested have the potential to replace the natural teeth in preclinical training.

Background: The aim of this study was to investigate whether boron nitride (BN) and BN–chromium (BN–Cr) coatings applied with the sputtering method would change the characteristics of hardness and discoloration of the ceramic veneer surface. Materials and Methods: In this experimental study, thirty disc-shaped cores (10 mm in diameter and 0.8 mm in thickness) were prepared. Three different ceramic systems, IPS Empress (E) (Ivoclar Vivadent, Schaan, Liechntenstein), IPS e.max Press (EP) (Ivoclar Vivadent, Schaan, Liechntenstein), and Turkom Cera (T) (Turcom-Ceramic SDN-BHD, Kuala Lumpur, Malaysia), were tested, each with n = 10. The specimens were divided into two subgroups (n = 5) according to the coating on the veneering ceramic: BN or BN–Cr. The Vickers hardness and color differences (ΔE) values were measured before and after coating. Surface analysis was performed with X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopic. The Wilcoxon signed-rank test was performed to compare hardness values. The Kruskal–Wallis test was performed to compare ΔE values among all groups. The post hoc tests was used after Kruskal–Wallis, with level of statistical significance set at P ≤ 0.05. Results: BN–Cr coating statistically significantly increased the hardness of all types of ceramics (P < 0.05). BN coating did not change the hardness statistically significantly (P > 0.05). The mean ΔE values indicated clinically noticeable (over the limit of 3.7) color change in all groups except for the EP-BN and T-BN groups. Conclusion: Although BN–Cr coating in this thickness had a negative effect on color, it increased the hardness of the ceramics and could be useful in the palatal region.

Background: This study investigated the influence of erbium-doped: yttrium aluminum garnet (Er:YAG) laser on the pull-out fracture load of fiber-reinforced composite (FRC) posts luted to dentin with different resin cements. Materials and Methods: In this in vitro experimental study, 90 premolars were endodontically treated. The post spaces were prepared, and the teeth were divided into three groups dependent on the cement applied for luting FRC posts: Group 1: An etch-and-rinse system, Group 2: A self-etch cement, and Group 3: A self-adhesive cement. After 6 months' storage and thermocycling, each group was divided into three subgroups (n = 10) according to the treatment applied for removing the posts; subgroup 1: Control, subgroup 2: Treatment with Er:YAG laser at 250 mJ, 20 Hz, and subgroup 3: Treatment by Er:YAG laser at 300 mJ, 10 Hz. The pull-out load was recorded in Newton. The data were analyzed by two-way ANOVA at P < 0.05. Results: The fracture load was significantly affected by the cementation group (P = 0.005) and treatment subgroup (P = 0.008). The pull-out load of self-etch cement was significantly greater than that of the self-adhesive and etch-and-rinse systems (P < 0.05). Treatment with Er:YAG laser caused a significant reduction in pull-out load of FRC posts (P < 0.05). Conclusion: The fracture load of fiber posts is influenced by the type of cement and treatment applied. Post removal would be less challenging when using a self-adhesive or conventional etch-and-rinse cement or using Er:YAG laser at the FRC-resin interface.

Background: Remineralization is currently considered a treatment option for many clinicians. The present study was conducted to compare the effect of three remineralizing agents on microhardness of initial caries lesions in primary teeth. Materials and Methods: In this in vitro study, 96 enamel samples were prepared. Microhardness was first measured for all the samples using the Vickers microhardness test. After developing the initial caries lesions, the microhardness of all the demineralized samples was measured, and the samples were then divided into four groups (n = 24). Casein phosphopeptide–amorphous calcium phosphate in Group 1, Remin Pro in Group 2, and acidulated phosphate fluoride gel in Group 3 were placed on the samples for 4 min. The control group received no treatments. The microhardness of the samples was measured again following a pH cycle of 5 days. The data were analyzed by ANOVA and the post hoc test at the significance level of P < 0.05. Results: The mean microhardness reduced significantly in all the groups following the development of initial caries lesions and after the pH cycle of 3 days (P < 0.001). After the remineralization and pH cycle of 5 days, the mean microhardness was significantly lower in the control group compared to the other three groups (P < 0.001) and had increased in the three treated groups. The microhardness recovery rate also increased in the treated groups compared to the control group, but no significant differences were observed between the three groups themselves (P > 0.05). Conclusion: Remin Pro can be used as an effective substance for preventing tooth caries in children.

Canalicular adenoma (CA) is a rare, benign salivary gland tumor that has special tendency to occur in the upper lip. Buccal mucosa is the second most common site. It occurs more often in older patients with peak prevalence in the seventh decade of life. A definitive female predominance has been reported. According to the latest English published literature, 531 cases of CA have been reported. We present a case of CA of the hard palate that presented in a 29-year-old female patient. The histopathological and immunohistochemical findings showed typical features of CA and intense expression of pan-cytokeratin and S-100 protein. We also review its differential diagnosis from other salivary gland tumors.

Background: The maximum conservation of tooth structure and the use of restorative materials with elastic modulus close to the dental structure may promote greater longevity of the tooth/restoration complex. This study was conducted to evaluate the effect of cavity design and material type on fracture resistance and failure pattern of molars restored by computer-aided design/computer-aided manufacturing (CAD/CAM) inlays/onlays. Materials and Methods: In this in vitro study, 55 human maxillary molars were embedded in resin blocks and divided into control group (CG) and five main groups: Group 1: Inlay, Group 2: Conventional onlay/mesiobuccal (MB), Group 3: Conservative onlay/MB, Group 4: Conventional onlay/MB and distobuccal (DB), and Group 5: Conservative onlay/MB and DB. Then, each group was divided into two subgroups: (A) CeraSmart (CS) and (B) Katana Zirconia (KZ). Restorations were cemented by RelyX Ultimate and then thermocycled. The universal testing machine was used to measure fracture loads. Failure was determined using a magnifying lens. Data were statistically analyzed using ANOVA followed by Tukey's post hoc test (P < 0.05). Results: Group 5 showed the highest significant fracture load, whereas the least significant value was recorded in Group 2. KZ recorded higher significant fracture loads than CS in all tested groups. Groups 1, 2, and 3 restored by CS showed lower fracture load than CG, but the difference was insignificant with Group 1. CS restorations showed restorable failure, while unrestorable pattern was predominant in KZ restorations (P < 0.05). Conclusion: KZ inlays and onlays can be used safely in terms of fracture resistance as both have values exceed the physiologic requirements. CS inlays and onlays/MB and DB are of fracture resistance comparable to intact teeth. The use of conservative onlay design with more cusp coverage guarantees better resistance of CS restorations. Being force absorbing material, the predominant failure of teeth restored by CS was restorable.

Background: The relative high caries risk of pits and fissures highlights the importance of protecting these areas. The aim is to determine the effect of sodium hypochlorite (NaOCl) on the shear bond strength (SBS) of resin-based pit and fissure sealant (RBPFS) material to enamel using resin-modified glass ionomer cement (RMGIC) and fluoride-releasing self-etch resin (FRSE) adhesives. Materials and Methods: In this in vitro study extracted third molar teeth without carious lesions or defects were divided into five experimental groups (n = 20). Group A: (Control group) etch (35% phosphoric acid) for 15 s and RBPFS applied. Group B: Etch for 15 s, FRSE and RBPFS applied. Group C: Pretreated with 5% NaOCl and similar steps to Group B. Group D: Etch for 15 s then RMGIC bonding agent and RBPFS applied. Group E: Pretreated with 5% NaOCl and then similar steps to Group D. SBS was determined using a universal testing machine. The tested specimens were examined under a field-emission scanning electron microscope. Data were analyzed using one-way ANOVA and post hoc Tukey's tests (P=0.05). Results: A statistically significant difference between the test groups was observed; Group C showed the highest SBS mean value (7.52 ± 2.74 MPa) and Group D showed the lowest (4.48 ± 1.81 MPa) (P < 0.001). Pretreatment with NaOCl increased the SBS of fissure sealant when Riva bond LC was used (P = 0.049). Conclusion: The use of NaOCl as pretreatment can increase the SBS of RBPFS to enamel using RMGIC adhesive. FRSE adhesive did not show improvement in SBS values using pretreatment.

Background: Various factors affect child behavior in different situations such as in a dental clinic. The purpose of this study was to investigate the relationship between temperament and child behavior during routine dental treatment. Materials and Methods: The present study is a descriptive-analytic study that included 199 children aged 3–7-years from patients referred to a dental clinic of Guilan University of Medical Sciences in 2017–2018. The Children's Behavior Questionnaire, which is specific to children aged 3–7 years, was used to assess children's dental temperament. Children's behaviors during dental treatment were recorded using Frankl scale. Finally, the data were analyzed by the SPSS-16 statistical software. Results: About 47.9% of the samples were female, with a mean temperament score of 4.79 which was significantly higher than males (P < 0.05). Almost 2.4% of children had completely negative behaviors and 2.8% had a completely positive behavior. The mean scores of fear (P = 0.008) and anger (P = 0.004) in children with completely negative behavior were higher than those with completely positive behavior. Moreover, the average scores of inhibitory control (P = 0.003) and perceptual sensitivity (P = 0.001) in completely positive children were higher than completely negative children. Conclusion: The results of the present study showed that girls had a better mean score of temperament than boys. The inhibitory control and perceptual sensitivity in completely positive children were significantly higher than negative children. In addition, a higher mean score of fear and anger was observed in completely negative children.

The current global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated coronavirus disease (COVID-19), has grasped the attention of entire international community and has caused widespread public health concerns. All the efforts taken globally to curtail the novel COVID-19; the outbreak is still on a rise owing to the community spread pattern of this infection. COVID-19 is a zoonotic infection that, like other coronavirus infections, is believed to have been originated in bats and pangolins, and later transmitted to humans. Once in the human body, this coronavirus (SARS-CoV-2) is abundantly present in nasopharyngeal and salivary secretions of affected patients and its spread is predominantly thought to be respiratory droplet in nature. Dental professionals may soon encounter patients with suspected or confirmed SARS-CoV-2 infection and will have to act carefully not only to provide care but at the same time prevent spread of infection. Thus, the aim of this article is to provide a brief overview of the epidemiology, symptoms and routes of spread of the novel COVID-19 infection. In addition to this, specific recommendations for dental practice are prescribed for patient screening, infection control strategies, and patient management protocol.

Background: Glass fiber posts, along with their esthetic properties, may have a better stress distribution than cast posts, Therefore, the aim of the present study was to investigate the effect of glass fiber, casting, titanium, and zirconia posts on stress distribution in maxillary central tooth treated with different amounts of ferrule using finite-element analysis. Materials and Methods: In this experimental study, three-dimensional models of maxillary central incisors that have undergone root canal treatment were designed. Then, the models were divided into four groups according to the type of post (Ni-Cr casting, glass fiber, titanium, and zirconia) used. Zirconia monolithic crowns were used in all the four groups. Ferrule heights were repeated at 0 and 2 mm in all models. Models were entered into COMSOL Metaphysics software. Then, the force of 100 N with the angle of 135° on the palatal surface was applied to the longitudinal axis of the tooth, and the stress distribution in the models was investigated. Results: Maximum stress was observed in the middle third of posts. Stress distribution in glass fiber post was better than zirconia and casting posts. Stress accumulation in models with zirconia, titanium, and casting posts was also found in the site between the middle third and coronal third, whereas in models with glass fiber post, stress accumulation was found between the crown and the cemento-enamel junction. In models without ferrule, stress accumulation was observed in one-third of the coronal, especially in glass fiber posts. Conclusion: The post material and ferrule height affected stress concentration. The stress in the cervical area of the dentin was more for glass fiber post when compared to other posts. The use of glass fiber post in teeth with no ferrule results in lower stress along the post, but greater stress in the simulated tooth region.

Background: This study was conducted to compare the shear bond strength (SBS) of orthodontic brackets to amalgam surfaces by two surface treatment methods, two different adhesives, and one intermediate resin and also to evaluate surface roughness after two preparation methods as well as bond failure mode. Materials and Methods: In this in-vitro study forty-eight amalgam samples were randomly allocated to four groups. In Groups 1–3, specimens were sandblasted with 50 μm aluminum oxide, followed by application of Alloy primer in Groups 1 and 2. In Group 3 Alloy primer had not used. In Group 4, samples were prepared by silica coating using a silane coupling agent. Surface roughness analysis was performed in 10 additional samples after two surface treatments. The brackets in Group 1 were bonded with Transbond XT and those in other groups were bonded with Panavia V5. All specimens were examined for SBS following 5000 times thermocycling at 5°C–50°C. Modified adhesive remnant index was utilized for the bond failure mode. Data analysis was done by one-way analysis of variance, post hoc Tukey, Kruskal–Walli and Mann–Whitney U tests. Statistical significance was set at P < 0.05. Results: The findings indicated the mean SBS were low (ranged from 0.19 to 4.66 MPa) and significantly lower in Group 3 than in Group 4 (P = 0.009). Bond failure occurred in adhesive/amalgam interface in nearly all samples. Silica coating produced significantly lower roughness than sandblast (P = 0.009). Conclusion: Silica coating had a significant higher bond strength than sandblast without application of Alloy primer. However compared to sandblast with Alloy primer, silica coating did not significantly improve the bond strength. Chemical bond between PanaviaV5 and sandblasted amalgam was not considerable.

Background: There is little information concerning the biocompatibility of mouthwashes containing metal nanoparticles. This study was conducted to assess the biocompatibility of colloidal solutions containing zinc oxide (ZnO), copper oxide (CuO), titanium dioxide (TiO2), and silver (Ag) nanoparticles compared with chlorhexidine (CHX) in a culture of human gingival fibroblasts (HGFs). Materials and Methods: This was an in vitro, experimental study. Nanoparticles, including ZnO, CuO, TiO2, and Ag, were purchased and added to a water-based solution to produce mouthwashes. The colloidal solutions and CHX were prepared at the minimum inhibitory concentration (MIC) against Streptococcus mutans and Streptococcus sanguis. Cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on HGFs at the concentrations of MIC, 0.1 MIC, and 0.01 MIC. To determine apoptosis, DNA fragmentation was assessed as “sub-G1” peak on DNA content histogram. The data were analyzed using repeated measures analysis at P < 0.05. Results: At all concentrations, the highest and lowest mean of cell viability was related to TiO2 and ZnO groups, respectively. At MIC, the mean cell viability was significantly greater in the TiO2 group than the other groups (except the Ag group) (P < 0.05). At the concentration of 0.01 MIC, the mean cell viability in the colloidal solution containing ZnO nanoparticles was significantly lower than the other solutions (P < 0.05). The CHX and CuO-containing solution displayed the highest rate of apoptosis among the groups. Conclusion: The TiO2-containing solution can be suggested as a suitable alternative to CHX to provide antiseptic effects with minimal toxicity.

Background: Various iron drops are prescribed to children to prevent iron-deficiency anemia. The current study aimed to evaluate and compare the physicochemical profile of iron drops and the effect of these medicines on the color of primary teeth. Materials and Methods: On the commencement of this experimental study, the pH and viscosity of five types of iron drops were measured. For the purpose of the current study, sixty healthy anterior deciduous teeth were provided; thereafter, they were assigned to five groups and then exposed to iron drops. The color and color difference of each specimen were measured by VİTA Easyshade Compact after 2 weeks. The amount of absorbed iron was determined by atomic absorption. The data were analyzed using two-way ANOVA and Tukey's test (P < 0.05). Results: As evidenced by the obtained results, all medications demonstrated acidic pH and discoloration. The viscosity values of iron drops were reported to be within the range of 2.07–33.58 cP. Based on the results of Pearson's correlation coefficient test, discoloration showed a correlation with pH and atomic absorption (P < 0.05). Conclusion: Analyzed iron drops displayed low pH and discoloration higher than 3.3 which can be easily distinguished with naked eyes. Medicine labels should include warning statements on the feasibility of dental discoloration and erosion.

Background: Most parents believe that teething is associated with some symptoms and commonly use Internet to gain more information about the health of their children. Pediatricians can also serve as a source of information for health-related requirements of parents. This study aimed to compare the information provided by pediatricians regarding tooth eruption and the information available in Persian-language websites. Materials and Methods: This descriptive, analytical, cross-sectional study was performed in two phases. In the first phase, the questionnaire was designed by 85 pediatric pediatricians in Isfahan about children's dental eruption and internet resources. The second phase was the study of 22 Persian websites about children's tooth eruption using Google search engine and the keywords “tooth eruption,” “tooth eruption symptoms.” Then a checklist was prepared to evaluate the quality and completeness of the content. Data were analyzed by the Chi-square test and Fisher's exact test using SPSS (P < 0.05). Results: None of the retrieved websites had the health on the net code of conduct. The most common symptoms of teething reported by both pediatricians and websites included irritability, drooling, gingival tenderness, chewing tendency, decreased appetite and sleep disturbances. In non-pharmacological methods to control the symptoms related to tooth eruption in both groups, embracing the baby (P < 0.001), using soft tooth ring (P = 0.049) and chewing hard foods (0.016 P = significant. Use of oral pain medication (P = 0.01) and sedatives and medications (P = 0.04) were significant in the medication method. Conclusion: None of the websites reviewed had a valid source code and author. Although websites cannot replace the instructions of pediatricians regarding growth and development of children and their teething, supplementary information can be acquired from high-quality websites because there seems to be no significant difference between these two information sources regarding tooth eruption symptoms and their management.

Background: Nickel-titanium (NiTi) open coils are common tools in fixed orthodontic treatments to apply light and continuous forces. Their favorable mechanical properties and their relatively high cost have prompted many clinicians to decide to reuse them. Aim: The present study aimed to evaluate the effect of 10% hydrochloric acid (HCl) and 5.25% sodium hypochlorite (NaClO) solution and sterilization, on the unloading force of NiTi open-coils. Materials and Methods: This experimental in vitro study consisted of 160 NiTi open coils from two brands of Highland Metals and Masel were provided. Each group was randomly divided into four subgroups: control, three rounds of immersion, three rounds of autoclave sterilization, and three rounds of immersion and autoclaving. Each round of immersion process included 1 min in 10% HCl, followed by 5 min in 5.25% NaClO. Spring was compressed for 4 mm. Then, the unloading forces of each spring were recorded at 4, 3, 2, and 1 mm of compression, respectively. The data were analyzed with SPSS (P < 0.05), using one-way ANOVA and independent t-test. Results: One-way ANOVA showed a significant difference in the 2-mm compression of Group 1 and 3-mm compressions of Groups 1 and 2 compared to the control group in the Highland metals brand (P < 0.04, P < 0.014, and P < 0.007, respectively). There was no significant difference between the different compressed lengths and groups in the Masel brand. Conclusion: One-minute immersion in 10% HCL and 5-min immersion in 5.25% NaOCl, followed by autoclave sterilization, even after repeating the process three times, did not significantly change the force properties of NiTi open springs. Therefore, the re-use of these springs with the above-mentioned method as preparation can be recommended.

Background: Various systemic diseases can cause oral manifestations, such as inflammatory bowel disease (IBD). This study is designed to investigate the frequency of oral manifestations in patients with IBD referred to health centers and offices in Isfahan in 2018. Materials and Methods: This cross-sectional study was done among 161 patients suffering from IBD in Isfahan, Iran. They were chosen by the systematic randomized sampling. Finally, the data were analyzed using the logistic regression test in the SPSS software. Significance was assigned at P < 0.05. Results: The number of patients with ulcerative colitis and Crohn's syndrome was, respectively, 119 persons (73.9%) and 42 persons (26.1%). Oral manifestations were seen among 52 (32.3%) of the samples. The frequency of oral manifestations was 35.6% (31 cases) in males and 28.4% (21 cases) in females. Oral manifestations were seen in 29.4% of patients with ulcerative colitis and 40.5% of patients with Crohn's disease. Based on the logistic regression, there was a statistically significant relationship between the use of azathioprine and mesalazine with oral manifestations (P < 0.05), whereas the severity of disease and smoking were not statistically significantly related to oral manifestations (P > 0.05). Conclusion: The severity of the disease was not significantly correlated with oral manifestations, which are in agreement with the results of previous studies. It was also found that among patients with IBD, the oral aphthous ulcers can appear 1–3 years before the diagnosis of the disease. Besides that, some of the drugs used to treat the disease have a significant relationship with oral manifestations.

Background: This study assessed the antimicrobial activity of Biodentine, mineral trioxide aggregate (MTA), and calcium-enriched mixture (CEM) cement against Enterococcus faecalis, Streptococcus mutans , and Candida albicans. Materials and Methods: In this in vitro study, microbial suspensions were inoculated onto agar plates. The antimicrobial effects of MTA, Biodentine and CEM cement were assessed against E. faecalis, S. mutans, and C. albicans by the agar diffusion test. In each experimental group, 7 plates containing 3 wells were prepared and immediately filled with freshly mixed cements. Positive and negative control plates were prepared with/without the bacterial suspension, respectively. After 2 h of preincubation at room temperature, the plates were incubated at 37°C for 24 h. The diameter of growth inhibition zones was measured after 24 h. Data were analyzed using ANOVA and Tukey's test (α = 0.05). Results: Biodentine showed strong antimicrobial activity against all three microorganisms with an average inhibition zone of 9.10 mm. The inhibitory effect of Biodentine on E. faecalis and C. albicans was significantly superior to that of the other two cements (P < 0.05). MTA and CEM cement showed significantly higher antimicrobial activity against S. mutans (P < 0.05). The antimicrobial effects of Biodentine on S. mutans and E. faecalis were significantly greater than on C. albicans (P < 0.05). Conclusion: All cements revealed antimicrobial properties against the tested microbial strains. Biodentine had stronger antimicrobial effects against E. faecalis and C. albicans compared with MTA and CEM cement. Furthermore, the largest inhibition zones around all three cements belonged to S. mutans.

Background: The purpose of this study was to compare the microhardness values of ProRoot mineral trioxide aggregate (MTA), Biodentine, and total fill root repair material (TF-RRM) Putty at varying pH and times. Materials and Methods: In this laboratory experiment, materials were mixed and placed in cylinder blocks with internal dimensions of 6 mm × 4 mm. Ten samples of each material were soaked in buffered solutions of butyric acid with 4.4, 5.4, 6.4, and 7.4 pH values and stored at 37°C in 100% humidity. The samples were submitted to the microhardness test at the end of 1 week and then 1 month. Multivariate analysis of variance and Tukey honestly significant difference tests were carried out to compare the mean values at a significance level of P < 0.05. Results: Low pH caused a significant decrease in the microhardness values of all samples. Surface microhardness increased with time (P < 0.0001). The microhardness values of Biodentine were significantly greater than those of ProRoot MTA and TF-RRM putty (P < 0.0001). The lowest microhardness values were recorded for TF-RRM putty groups regardless of the pH of the environment and the evaluation time. Conclusion: An acidic environment impaired the surface microhardness of all root repair materials tested. Overall, the mean surface microhardness of TF-RRM Putty was lower than those of ProRoot MTA and Biodentine. Biodentine showed the greatest microhardness values at all pH values, regardless of the evaluation time.

Background: The “All-on-four” concept for treatment of edentulous arches incorporates four implants that are placed in between mental foramina in the mandible. The prosthetic framework is an important parameter in stress/strain concentration at the implants, prosthesis, and the underlying bone. Materials such as titanium, zirconia, and carbon fibers have been used for fabrication of framework in the past. The aim of this study was to analyze the effect of framework materials in the “All-on-four” implant system. Materials and Methods: Finite element three-dimensional (3D) model of edentulous mandible was simulated using a computerized tomographic scan data of an edentulous patient. Threaded implants were replicated along with the abutments using 3D modeling software and the framework was designed and simulated using material properties of titanium, zirconia, and polyetheretherketone (PEEK). Axial and nonaxial load of 200 N was applied at the abutment region of right distal implants. The computer-generated numerical values were tabulated and analysed by ANSYS software. Results: Principal strain, von Mises stress and micromotion were assessed in the peri-implant bone region to evaluate its stress condition. Zirconia framework showed the least stress/strain values at axial and oblique loading. Maximum strain values were seen at the PEEK framework material. Zirconia framework in all models showed the least micromotion/displacement. Conclusion: The stress distribution pattern at implant–bone interface was influenced by the framework material used. The framework material, loading site, and direction of forces influenced the stresses and displacement at the bone–implant interface.