Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
  • Users Online: 545
  • Home
  • Print this page
  • Email this page


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2019  |  Volume : 16  |  Issue : 4  |  Page : 216-220

Evaluation of sealing abilitiy of mineral trioxide aggregate mixed with propylene glycol as a root canal sealer: A in vitro study


1 Dental and Periodontal Research Center, Faculty of Dentistry, Tabriz University of Medical Sciences, Urmia, Iran
2 Dentist, Private Practice, Tabriz, Iran
3 Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Urmia, Iran
4 Department of Endodontics, Dental and Periodontal Research Center, Tabriz University of Medical Sciences, Urmia, Iran
5 Department of Endodontics, Dental School, West Azarbaijan, Urmia University of Medical Sciences, Urmia, Iran

Date of Web Publication24-Jun-2019

Correspondence Address:
Dr. Amir Ardalan Abdollahi
Department of Endodontics, Dental School, West Azarbaijan, Urmia University of MedicalSciences, Urmia
Iran
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1735-3327.261124

Rights and Permissions
  Abstract 


Background: Sealing ability is one of the most important features of endodontic sealers. The main goal of the present study was to compare sealing ability of mineral trioxide aggregate (MTA)-propylene glycol (PG) with two commonly used resin-based and MTA-based sealers.
Materials and Methods: In This in vitro study Seventy extracted single-root teeth were used. Canal preparation was carried out using hand and RaCe rotary files. Ten teeth were used as control. The root canals in positive and negative control groups were left empty. Remaining 60 teeth were randomly divided into following four groups (n = 15): In Group 1, the canals were dried using paper cones and obturated using MTA-PG sealer. In Group 2, saline was removed from canal using a syring, but paper cones were not used. Obturation was done using MTA-PG sealer. In Groups 3 and 4, the canals were dried using paper cones and obturated with AH26 and MTA Fillapex, respectively. Two-chamber method was used to evaluate bacterial leakage using Enterococcus faecalis (ATCC 29212). Turbidity of the lower chambers was checked every day during 90 days. Chi-square, Kaplan–Meier analysis, and logrank tests were used to compare groups regarding leaked samples at the end of the study. The level of significance was set at 0.05.
Results: There was no significant difference among groups regarding rate of leakage throughout the study. However, at the end of the study, the groups were statistically different regarding leaked samples (P = 0.034). MTA Fillapex and MTA-PG in dry canal showed the most and least leaked samples at the end of the study, respectively (P < 0.05).
Conclusion: MTA mixed with PG has superior sealing ability than MTA Fillapex.

Keywords: Dental leakage, mineral trioxide aggregate, propylene glycol, sealing


How to cite this article:
Milani AS, Firuzi S, Barhaghi MH, Shahi S, Abdollahi AA. Evaluation of sealing abilitiy of mineral trioxide aggregate mixed with propylene glycol as a root canal sealer: A in vitro study. Dent Res J 2019;16:216-20

How to cite this URL:
Milani AS, Firuzi S, Barhaghi MH, Shahi S, Abdollahi AA. Evaluation of sealing abilitiy of mineral trioxide aggregate mixed with propylene glycol as a root canal sealer: A in vitro study. Dent Res J [serial online] 2019 [cited 2019 Aug 20];16:216-20. Available from: http://www.drjjournal.net/text.asp?2019/16/4/216/261124




  Introduction Top


Mineral trioxide aggregate (MTA) has several desirable properties such as high biocompatibility and low cytotoxicity,[1] release of calcium hydroxide (Ca(OH)2),[2] sealing ability against the bacteria and saliva,[3] antibacterial features,[4] ability of setting in the presence of bleeding or serum,[5] adequate compressive strength, and acceptable hardness.[4] Thus, it has been one of the commonly used biomaterials in endodontics.

Despite these advantages, long setting time[4] and difficult manipulation[2] are the drawbacks of MTA. To improve these properties, some changes have been made in its liquid or powder.[6],[7],[8] One of the materials that have been mixed with MTA to enhance its manipulation is propylene glycol.[7],[9]

Propylene glycol (1,2-propanediol) (PG) is a dihydric alcohol without toxicity, carcinogenicity, or genotoxicity.[10] One of the vital properties of PG is its suitable consistency which results in better handling of materials.[7] Furthermore, studies have shown that PG has antibacterial characteristics against the bacteria involved in endodontic infections.[11] In addition, the dentine penetration of PG is more than distilled water (DW).[10] Furthermore, mixing Ca(OH)2 with PG resulted in improved release of Ca2+ and OH and increased pH of dentin and cementum.[12] According to these desirable properties of PG, several studies have investigated the use of this material to improve handling of MTA.[6],[8]

Aforementioned favorable properties of MTA persuaded researchers to use it as a root canal sealer; however, sandy consistency of MTA mixed with water makes it unsuitable as a sealer. Mixing MTA with PG causes improved consistency with low film thickness and facilitates its insertion in the root canal. Hence, this mixture may potentially be used as a sealer. Studies evaluating MTA-based sealers such as MTA Fillapex have shown disadvantages like higher cytotoxicity and lower sealing in comparison to resin-based sealers,[13],[14] and furthermore, some studies reported lower biocompatibility of MTA Fillapex than MTA.[15] These drawbacks have been attributed to low percentage of MTA in the sealer composition and presence of resin and other additives.[13],[14]

The main goal of the present study was to compare sealing ability of MTA-PG with two commonly used resin- (AH26) and MTA-based (MTA Fillapex) sealers.

MTA and PG both have hydrophilic characteristics, and studies have suggested that moisture is needed for the setting of MTA-based sealers.[16] If MTA is used as a sealer (e.g., MTA-PG or MTA-based sealers), complete drying the canal before sealer placement may theoretically inhibit complete setting.[17] Nagas et al.[17] showed that the canal drying technique influenced the bond strength between MTA-based sealers and dentine. This was also confirmed by Tasdemir et al.[16] They proposed that it may be advantageous to leave canals slightly wet before obturating with MTA-based sealers. The question is whether canal drying technique influence sealing ability of MTA-based sealers. There is no study in literature to answer this question. Therefore, the second goal of the present study was to evaluate the effect of canal moisture on sealing ability of MTA-PG sealer.


  Materials and Methods Top


This in vitro study was approved by the Research and Ethics Committee of Tabriz University of Medical Sciences. Seventy extracted human single-rooted premolar teeth extracted for periodontal reasons were selected for this study. All the teeth had mature single straight roots, with no root caries, previous endodontic treatments or anomalies. Furthermore, the teeth with cracks or fractures and pulp chamber or canal calcifications were excluded. Following extraction, each tooth was stored in 3% chloramine-T solution at 4°C. The external root surface was cleaned with ultrasonic tips to remove the remnants of periodontal tissues. The coronal portions of the teeth were then dissected to achieve the root lengths of 15 mm. Teeth were selected with apical foramina approximately matching the size of #30 K-Flexofile (Dentsply, Maillefer, Ballaigues, Switzerland). The working length was determined with #15 K-Flexofile, 1 mm from the radiographic apex. All the root canals were prepared in a crown down manner using #4 and 3 Gates-Glidden drills (Dentsply, Maillefer, Ballaigues, Switzerland) for coronal two-thirds preparations, followed by the use of 40/0.10, 35/0.08, 25/0.04, 25/0.06, 30/0.06, and 35/0.06 RaCe rotary instruments (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The size of master apical file was ascertained at #35. Each canal was irrigated with 2.5% NaOCl (Taj Corp, Tehran, IRI) throughout the instrumentation sequence. The smear layer was removed using 1 mL of 17% ethylenediaminetetraacetic acid (Pulpdent Corp., Watertown, MA, USA) for 3 min, followed by a rinse with 1 mL of 5.25% NaOCl for 3 min. Finally, the canals were irrigated with 5 mL of normal saline (injection pharmaceutical products company, Tehran, Iran) solution.[12]

Experimental groups

The 70 samples were randomly divided into four experimental groups (n = 15) and one positive control and negative control groups (n = 5). The experimental groups were subjected to each of the following experimental treatment protocols: Group 1: after drying the canal with paper point (Meta Biomed, Korea, Iran) and MTA (Angelus, Londrina, Brazil) +50% PG (Merck, Germany) and 50% DW was placed in the root canals by a lentulo size #40. Then, the Gutta-percha cones were coated with sealer, and the canals were obturated with Gutta-percha (Gapadent, Korea) and MTA-PG sealer using a lateral condensation technique. Group 2: the normal saline existing in the canals was removed using a 2 mL syringe (Ava Luer lock, Tehran, Iran) and 27G needle (Ava pezeshk, Tehran, Iran). However, paper point was not used for drying the canals. Other procedures were performed same as Group 1. In Groups 3 and 4, the treatment protocols were carried out same as Group 1, but the sealers were AH26 (Dentsply, DeTrey, Konstanz, Germany) and MTA Fillapex (Angelus, Londrina, Brazil), respectively. The DW/PG ratios were determined by volume, and the powder/liquid ratio was the same for Groups 1 and 2 (1 g powder to 0.33 mL liquid). The root canals in positive and negative control groups were left empty. All the root surfaces of the teeth were covered with two layers of cyanoacrylate adhesive (Super Bonder, Loctite) except for 2 mm of apical portion. In the negative control, the specimens were completely sealed with two layers of cyanoacrylate adhesive. After that, the samples were stored at 37°C and 100% humidity for 48 h.

Bacterial leakage test

A double-chamber method was used for evaluating the sealing ability of the samples. Each tooth was inserted in a plastic microtube (0.5 mm × 1.5 mm) that worked as a bacterial reservoir. The tube end was pierced to make the root end come out of the tube. The interfaces between the teeth and the tube holes were sealed with cyanoacrylate adhesive (Super Bonder, Loctite). The system (tooth inserted in a plastic tube) was autoclaved at 15 psi and 121°C for 15 min and placed in a sterilized 50 ml glass flask containing 10 ml sterile brain–heart infusion broth (BHI-Oxid Ltd, Hanks, USA) in a way that the 2 mm root end was placed in the BHI broth. The interface between the tube and glass flask was also sealed with cyanoacrylate adhesive. Then, the samples were incubated in 37°C for 7 days. In this time period, any samples of BHI broth which had become turbid was excluded from the study.

A bacterial suspension of Enterococcus faecalis (ATCC 29212, Reference Laboratories of Iran Research Center, Tehran, Iran) at concentration of 0.5 × 108 CFU/mL was used. 0.1 mL of the bacterial suspension was injected in the pulp chamber of the teeth existing in the microtubes every other day. The whole system was incubated at 37°C for 90 days, and the BHI turbidity was evaluated every day. The turbid solutions were recorded as positive leakage and the date also recorded.[12]

Statistical analysis

Statistical analysis was performed using SPSS software (SPSS version 20.0, SPSS, Chicago, IL, USA). Kaplan–Meier analysis and logrank test were used to compare the rate of bacterial leakage between groups. Chi-square test was used to compare groups regarding leaked samples at the end of the study. The level of significance was set at 0.05.


  Results Top


The positive control group showed leakage in all specimens in the first 24 h while the negative control group showed no sample with leakage at the end of 90 days. At the end of the study, the groups were statistically different regarding the number of samples that showed leakage (P = 0.034) [Table 1]. According to [Table 1], MTA Fillapex (93.3%) and MTA-PG (46.7%) showed the most and the least number of samples with leakage in dry canals at the end of the study period (P < 0.05). However, there was not any significant difference among groups regarding rate of leakage during study (P = 0.519) [Figure 1].
Table 1: Number (percentage) of samples with leakage at the end of 90 days

Click here to view
Figure 1: The rate of bacterial leakage in study groups during 90 days of study. CUM: Cumulative.

Click here to view



  Discussion Top


Sealing properties of root canal sealers have vital role in success of endodontic treatment. Ideally, the root canal obturating materials should be biocompatible and seal the root canal system.[18] Several studies have evaluated the efficacy of mixture of MTA with different vehicles, to improve the characteristics of MTA-based sealers.[16],[18] According to the previous studies indicating desirable PG properties as a vehicle,[9],[10] this study compared sealing ability of MTA-PG with two commonly used resin- (AH26) and MTA-based (MTA Fillapex) sealers using bacterial leakage test.

Several methods such as electrochemical leakage,[19] dye leakage,[20] fluid infiltration,[21] protein leakage test,[3],[22] and bacterial leakage[12] have been used to evaluate leakage in various studies. The present study used bacterial leakage test since this model most closely simulates clinical situation.[22]

Various bacteria species have been used to assess the bacterial penetration in different studies.[23],[24] In this leakage study, E. faecalis was evaluated. This microorganism is commonly isolated pathogen in persistent endodontic infections.[25] Furthermore, E. faecalis is a highly resistant bacteria, and it grows without synergic supports. Furthermore, it has been widely used in previous bacterial leakage studies.[18],[26]

The results of the present study showed that although the leakage of MTA-PG in dry canals was lower than canals with moisture, the difference was not statistically significant. Ehsani et al.[27] reported contrasting results about MTA-based sealers (MTA Fillapex) and stated that moisture could negatively affect the sealing of all sealers except for MTA-based sealers. In contrast, Nagas et al.[17] and Tasdemir et al.[16] in two different studies concluded that the canal moisture significantly affects the bond strength of MTA-based sealers to root dentin, and canals with mild moisture had the highest bond strength.

According to the results of this study, although the leakage of MTA Fillapex was more than AH26 at the end of the study, the difference was not statistically significant. In concordance, Reyhani et al.[28] showed similar results. However, Sönmez et al.[29] in a study with dye penetration method reported that the leakage of MTA Fillapex was significantly more than MTA and AH26. Furthermore, Razavian et al.[14] and Oliveira et al.[18] in two different bacterial leakage studies demonstrated that the sealing ability of AH26 was significantly better than MTA Fillapex. This contrast may be attributed to the smaller sample size in the present study.

In this study, MTA-PG (46.7% leakage) showed significantly better sealing ability in dry canals in comparison to MTA Fillapex sealer (93.3%). This superiority of MTA-PG may be attributed to higher amount of MTA in the composition of MTA-PG. Furthermore, Brito-Júnior et al.[12] showed that adding PG to MTA increased its sealing ability in furcal perforations. These advantages of MTA-PG were attributed to the better homogeneity and decrease in cement porosity.[12] Furthermore, the other possible reason of improved sealing ability of PG-MTA is that this mixture may expand on setting.[30]

The present study showed promising results about the sealing ability of MTA-PG mixture as a root canal sealer. However, further studies including animal studies and also with other bacterial species of oral flora are necessary.


  Conclusion Top


Based on the results of this in vitro study, MTA mixed with PG has superior sealing ability than MTA Fillapex, and the root canal moisture has no significant effect on the bacterial leakage.

Acknowledgment

The authors wish to thank the Research Vice Chancellor and Dental and Periodontal Research Center of Tabriz University of Medical Sciences.



Financial support and sponsorship

The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or nonfinancial in this article.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Mozayeni MA, Milani AS, Marvasti LA, Asgary S. Cytotoxicity of calcium enriched mixture cement compared with mineral trioxide aggregate and intermediate restorative material. Aust Endod J 2012;38:70-5.  Back to cited text no. 1
    
2.
Camilleri J. Hydration mechanisms of mineral trioxide aggregate. Int Endod J 2007;40:462-70.  Back to cited text no. 2
    
3.
Vosoughhosseini S, Lotfi M, Shahmoradi K, Saghiri MA, Zand V, Mehdipour M, et al. Microleakage comparison of glass-ionomer and white mineral trioxide aggregate used as a coronal barrier in nonvital bleaching. Med Oral Patol Oral Cir Bucal 2011;16:e1017-21.  Back to cited text no. 3
    
4.
Parirokh M, Torabinejad M. Mineral trioxide aggregate: A comprehensive literature review-part I: Chemical, physical, and antibacterial properties. J Endod 2010;36:16-27.  Back to cited text no. 4
    
5.
Parirokh M, Torabinejad M. Mineral trioxide aggregate: A comprehensive literature review-part III: Clinical applications, drawbacks, and mechanism of action. J Endod 2010;36:400-13.  Back to cited text no. 5
    
6.
Ber BS, Hatton JF, Stewart GP. Chemical modification of proroot mta to improve handling characteristics and decrease setting time. J Endod 2007;33:1231-4.  Back to cited text no. 6
    
7.
Holland R, Mazuqueli L, de Souza V, Murata SS, Dezan Júnior E, Suzuki P, et al. Influence of the type of vehicle and limit of obturation on apical and periapical tissue response in dogs' teeth after root canal filling with mineral trioxide aggregate. J Endod 2007;33:693-7.  Back to cited text no. 7
    
8.
Hsieh SC, Teng NC, Lin YC, Lee PY, Ji DY, Chen CC, et al. Anovel accelerator for improving the handling properties of dental filling materials. J Endod 2009;35:1292-5.  Back to cited text no. 8
    
9.
Salem Milani A, Froughreyhani M, Charchi Aghdam S, Pournaghiazar F, Asghari Jafarabadi M. Mixing with propylene glycol enhances the bond strength of mineral trioxide aggregate to dentin. J Endod 2013;39:1452-5.  Back to cited text no. 9
    
10.
Duarte MA, Alves de Aguiar K, Zeferino MA, Vivan RR, Ordinola-Zapata R, Tanomaru-Filho M, et al. Evaluation of the propylene glycol association on some physical and chemical properties of mineral trioxide aggregate. Int Endod J 2012;45:565-70.  Back to cited text no. 10
    
11.
Ganesh MR, Chaurasia VR, Masamatti VK, Mujeeb A, Jhamb A, Agarwal JH, et al. In vitro evaluation of antibacterial efficacy of calcium hydroxide in different vehicles. J Int Soc Prev Community Dent 2014;4:56-60.  Back to cited text no. 11
    
12.
Brito-Júnior M, Viana FA, Pereira RD, Nobre SA, Soares JA, Camilo CC, et al. Sealing ability of MTA-angelus with propyleneglycol in furcal perforations. Acta Odontol Latinoam 2010;23:124-8.  Back to cited text no. 12
    
13.
Zhou HM, Du TF, Shen Y, Wang ZJ, Zheng YF, Haapasalo M, et al. In vitro cytotoxicity of calcium silicate-containing endodontic sealers. J Endod 2015;41:56-61.  Back to cited text no. 13
    
14.
Razavian H, Barekatain B, Shadmehr E, Khatami M, Bagheri F, Heidari F, et al. Bacterial leakage in root canals filled with resin-based and mineral trioxide aggregate-based sealers. Dent Res J (Isfahan) 2014;11:599-603.  Back to cited text no. 14
    
15.
Bósio CC, Felippe GS, Bortoluzzi EA, Felippe MC, Felippe WT, Rivero ER, et al. Subcutaneous connective tissue reactions to iRoot SP, mineral trioxide aggregate (MTA) fillapex, diaRoot bioAggregate and MTA. Int Endod J 2014;47:667-74.  Back to cited text no. 15
    
16.
Taşdemir T, Er K, Çelik D, Tahan E, Serper A, Ceyhanli KT, et al. Bond strength of calcium silicate-based sealers to dentine dried with different techniques. Med Princ Pract 2014;23:373-6.  Back to cited text no. 16
    
17.
Nagas E, Uyanik MO, Eymirli A, Cehreli ZC, Vallittu PK, Lassila LV, et al. Dentin moisture conditions affect the adhesion of root canal sealers. J Endod 2012;38:240-4.  Back to cited text no. 17
    
18.
Oliveira AC, Tanomaru JM, Faria-Junior N, Tanomaru-Filho M. Bacterial leakage in root canals filled with conventional and MTA-based sealers. Int Endod J 2011;44:370-5.  Back to cited text no. 18
    
19.
Amditis C, Bryant RW, Blackler SM. The assessment of apical leakage of root-filled teeth by the electrochemical technique. Aust Dent J 1993;38:22-7.  Back to cited text no. 19
    
20.
Zmener O, Pameijer CH, Serrano SA, Vidueira M, Macchi RL. Significance of moist root canal dentin with the use of methacrylate-based endodontic sealers: An in vitro coronal dye leakage study. J Endod 2008;34:76-9.  Back to cited text no. 20
    
21.
Yilmaz Z, Tuncel B, Ozdemir HO, Serper A. Microleakage evaluation of roots filled with different obturation techniques and sealers. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:124-8.  Back to cited text no. 21
    
22.
Lotfi M, Vosoughhosseini S, Saghiri M, Zand V, Yavari HR, Kimyai S, et al. Effect of alkaline ph on sealing ability of white mineral trioxide aggregate. Med Oral Patol Oral Cir Bucal 2011;16:e1014-6.  Back to cited text no. 22
    
23.
Williamson AE, Marker KL, Drake DR, Dawson DV, Walton RE. Resin-based versus gutta-percha-based root canal obturation: Influence on bacterial leakage in an in vitro model system. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:292-6.  Back to cited text no. 23
    
24.
Zand V, Salem-Milani A, Shahi S, Akhi MT, Vazifekhah S. Efficacy of different concentrations of sodium hypochlorite and chlorhexidine in disinfection of contaminated resilon cones. Med Oral Patol Oral Cir Bucal 2012;17:e352-5.  Back to cited text no. 24
    
25.
Gajan EB, Aghazadeh M, Abashov R, Salem Milani A, Moosavi Z. Microbial flora of root canals of pulpally-infected teeth: Enterococcus faecalis a prevalent species. J Dent Res Dent Clin Dent Prospects 2009;3:24-7.  Back to cited text no. 25
    
26.
Milani AS, Jafarabadi MA, Pakdel MV. Using mineral trioxide aggregate powder as an apical barrier: A bacterial leakage study. Gen Dent 2014;62:55-9.  Back to cited text no. 26
    
27.
Ehsani M, Dehghani A, Abesi F, Khafri S, Ghadiri Dehkordi S. Evaluation of apical micro-leakage of different endodontic sealers in the presence and absence of moisture. J Dent Res Dent Clin Dent Prospects 2014;8:125-9.  Back to cited text no. 27
    
28.
Reyhani MF, Ghasemi N, Rahimi S, Milani AS, Barhaghi MH, Azadi A, et al. Apical microleakage of AH plus and MTA fillapex® sealers in association with immediate and delayed post space preparation: A bacterial leakage study. Minerva Stomatol 2015;64:129-34.  Back to cited text no. 28
    
29.
Sönmez IS, Oba AA, Sönmez D, Almaz ME.In vitro evaluation of apical microleakage of a new MTA-based sealer. Eur Arch Paediatr Dent 2012;13:252-5.  Back to cited text no. 29
    
30.
Storm B, Eichmiller FC, Tordik PA, Goodell GG. Setting expansion of gray and white mineral trioxide aggregate and portland cement. J Endod 2008;34:80-2.  Back to cited text no. 30
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1]



 

Top
 
 
Search
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
Conclusion
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed465    
    Printed27    
    Emailed0    
    PDF Downloaded86    
    Comments [Add]    

Recommend this journal