Calcium Hydroxide-based Sealer Research Articles

Outcomes of root canal treatments with three different sealers for 120 fractured maxillary fourth premolar teeth in small-to medium-sized dogs.

Tooth fracture is one of the most common traumatic maxillofacial injuries in dogs and cats. For fractures with pulp exposure occurring in functionally important teeth, the literature indicates that root canal treatment (RCT) is an effective therapy option that may be the remedy of choice before extraction. The most commonly reported fractures in the United States involve canine teeth; however, fractures of the maxillary fourth premolars are more common in Korea, where there are many small-and medium-sized dogs. RCT mechanically and chemically removes pulp tissue and bacteria (cleaning and shaping) from the infected root canal, and obturates the root canal with filling material to restore tooth functionality without inflammation. Various techniques, instruments, and materials used in humans have been modified for application in veterinary dentistry. This study analyzed the results of RCT of the maxillary fourth premolar in 120 small-and medium-sized dogs (weighing less than 25 kg) using three different sealers (silicone-based sealer, bioceramic sealer, and calcium hydroxide-based sealer) through a simple application of the single-cone technique. The overall success rate of RCT in maxillary fourth premolars was 90.83%, with 8.33% no evidence of failure (NEF) and 0.83% failure. There were no significant differences between the three different sealers. Furthermore, preexisting periapical lesion (PAL) was reconfirmed as a factor in reducing the success rate of RCT. In addition, the working length and master apical file of each root were analyzed in our study as a novel reference for endodontic veterinarians.

Assessment of the impact of XP-Endo Finisher file on push-out bond strength of various endodontic sealers.

An endodontic treatment is considered a success after thorough chemomechanical debridement coupled with obturating root canals in a concrete way thereby providing hermetic seal. Gutta-percha being nonadherent necessitates use of a sealer to achieve hermetic seal. Adequate adhesion of root canal sealer with gutta-percha core and radicular dentin ensures lack of apical leakage. Sixty extracted mandibular premolars with single root canal decoronated at cementoenamel junction were selected and randomly allocated to two groups (n = 30). Samples in Group 1 were prepared with BT Race file, while Group 2 samples were prepared with BT Race alongwith XP Endo file. Absorbent paper points were used for canal drying and samples were randomly divided into six subgroups. In Subgroup I, obturation was done with bio-ceramic (BC) sealer (Endosequence BC) and BC gutta-percha. In Subgroup II, resin-based (AH plus) sealer and gutta-percha were used. In Subgroup III, calcium hydroxide-based (Sealapex) sealer and gutta-percha were used. Sectioning of root samples was done perpendicularly into coronal, middle, and apical segments of 3 mm each. A universal testing machine was used for sample testing, in which push-out bond strength corresponded to the highest value obtained. Stereomicroscopic (×20) study of the samples determined the failure mode at dentin/sealer/main cone interface. Analysis of variance and post hoc Tukey's tests were used for data analysis. Endosequence BC with XP-Endo files showed the highest mean push-out bond strength (16.31 MPa), whereas Sealapex without XP-Endo file had the lowest values (12.76 MPa). Mixed failure of adhesive and cohesive mode was observed for most samples. Adjunctive irrigation agitation technique utilizing XP-Endo Finisher facilitates biofilm eradication from difficult niches in root canals, thereby improving adhesion of sealer and subsequently the sealer bond strength.

The Short-Term Antibacterial Activity of Three Selected Endodontic Sealers against Enterococcus faecalis Bacterial Culture.

(1) Background: Microorganisms originating from the microflora of the oral cavity are the main cause of the inflammatory diseases of the dental pulp and periapical periodontium, as well as the failure of endodontic treatment. The subsequent root canal treatment is not able to remove all the pathogens, and a small number of viable bacteria remain in the dentine tubules, which must be sealed by endodontic sealers. These sealers should have at least a bacteriostatic effect to prevent the remaining bacteria from reproducing. The aim of this study is to compare the short-term antibacterial activity of three endodontic sealers based on poly-epoxy resin, zinc oxide-eugenol and calcium silicate with a calcium hydroxide-based sealer. Calcium hydroxide is used as temporary intracanal medicament and, thus, should show significant antibacterial activity. (2) Methods: A total of 25 bovine dentine samples infected with Enterococcus faecalis were used in this study. After the sealer placement and a 24 h incubation period, the root canal walls were scraped, and the suspension of dentine fillings was used for a semi-quantitative evaluation of microbial growth. (3) Results: The poly-epoxide resin-based sealer ADSeal™ showed significant antibacterial properties. (4) Conclusions: The highest antibacterial activity was shown in poly-epoxide resin-based sealer group, followed by the zinc oxide-eugenol-based sealer and calcium silicate-based sealer.

Efficacy of Bioceramic and Calcium Hydroxide-Based Root Canal Sealers against Pathogenic Endodontic Biofilms: An In vitro Study.

Complete eradication of root canal pathogens cannot be predictably achieved by chemomechanical preparation and root canal disinfection. Therefore, an obturation material that has superior antimicrobial activity and sealing ability is required to inactivate residual microbes and prevent them from reentering the root canal system. Recently developed bioceramic root canal sealers are hydraulic cement which form calcium hydroxide during the hydration process. Like calcium hydroxide sealers, they exert an antimicrobial effect by releasing hydroxyl ions and increasing the pH. The objective of this study was to evaluate and compare the antimicrobial activity of a calcium hydroxide-based sealer and two bioceramic sealers against Porphyromonas gingivalis, Enterococcus faecalis, and Candida albicans biofilms. The sealers were dissolved in sterile saline to obtain supernatants. Biofilm formation assays, colony counting, and real-time polymerase chain reaction (PCR) were performed to evaluate the antimicrobial activity of each supernatant. The data were analyzed using one-way analysis of variance. All sealers exerted effects against all three microbial biofilms. The biofilm formation assays showed that the bioceramic sealers were more effective against P. gingivalis and E. faecalis biofilms. In contrast, colony counting and real-time PCR showed that the calcium hydroxide sealer was significantly more effective than the bioceramic sealers. All tests showed that the calcium hydroxide sealer was more effective against C. albicans, with the colony count and real-time PCR results showing statistically significant differences. The calcium hydroxide-based sealer was more effective than the bioceramic sealers in eradicating pathogenic root canal biofilms.

Evaluation of The Sealing Ability of Gutta Percha with Bioroot RCS, MTA Fillapex and Sealapex - An SEM Study.

Aim of the Study:The objective of this in-vitro study was to assess the screening capabilities of three endodontic sealers, namely the BioRoot RCS, the MTA Fillapex, and Sealapex (a calcium hydroxide-based sealer), and the gutta-percha cone by using a scanning electron microscopy to the dentine walls. The results from the research are presented here.Results:ZOE exhibited more gaps in the sealing materials evaluated with the least dental sealing performance, followed by the cervical third by the MTA Fillapex, the Sealapex, and the BioRoot RCS. The ZOE, followed by Sealapex, MTA Fillapex, and BioRoot RCS, exhibited inadequate dental wall sealing capacity in the middle of the third. The third apical ZOE exhibited more deficiencies in the formation of dental walls, followed by Sealapex, MTA Fillapex, and BioRoot RCS.Conclusion:Under the constraints of the investigation, it can be stated that for the bioceramic sealer, a minimal gap was seen, with RCS of BioRoot superior to Fillapex of MTA. In the middle third, Sealapex was better adapted to the calcium hydroxide-based sealant than the MTA Fillapex sealer. MTA Filllapex had lower gap development than Sealapex in cervical or apical thirds.

An in vitro study on the effects of serum proteins on Enterococcus faecalis adhesion to three types of root sealers and gutta-percha

BackgroundThe extrusion of overfilled materials that extend beyond the apical foramina into the periradicular tissue may serve as a reservoir for bacterial adhesion and further affect recovery from periapical diseases. The aim of this study was to evaluate the effects of serum proteins on Enterococcus faecalis adhesion and survival on the surface of a calcium hydroxide-based root canal sealer (Apexit Plus), an epoxy resin sealer (AH-Plus) and a bioceramic sealer (iRoot SP).MethodsApexit Plus, AH-Plus and iRoot SP were evenly coated on gutta-percha, using gutta-percha alone as the control. After root canal sealer setting, the number of E. faecalis adhering to the root canal sealers and gutta-percha was counted in fetal bovine serum (FBS) or tryptic soy broth supplemented with 1% glucose (TSBG) by viable cell plate counts. The morphology of 7-day-old E. faecalis biofilms in FSB and TSBG was observed by scanning electron microscopy (SEM). Furthermore, E. faecalis biofilms on the three root canal sealers were labeled with a LIVE/DEAD BacLight™ Bacterial Viability Kit, and the ratios of viable to dead cells were analyzed using laser scanning microscopy operative software (Zen software).ResultsIn the assays, after 1 and 7 days, the number of E. faecalis adhering to the root canal sealers or gutta-percha in FBS were significantly lower than those in TSBG (P < 0.05). In FBS, E. faecalis adhesion to iRoot SP and gutta-percha was reduced to a greater extent than that adhered to Apexit Plus and AH-Plus. Few E. faecalis accumulated on iRoot SP in FBS, whereas many bacteria assembled on iRoot SP and formed biofilms in TSBG. The ratio of viable cells in the E. faecalis biofilm on iRoot SP was the lowest.ConclusionsCalcium hydroxide-based root canal sealers, epoxy resin sealers and bioceramic sealers may provide a substrate for E. faecalis adhesion, and the bioceramic sealer in this study showed the least E. faecalis adhesion in the presence of serum proteins compared to the other two sealers.

Microscopic evaluation of sealer penetration and interfacial adaptation of three different endodontic sealers: An in vitro study.

Background:The dentinal tubular penetration depth and interfacial adaptation of sealer are important factors for successful root canal treatment.Aims:This study aims to assess and evaluate the sealer penetration depth and interfacial adaptation of AH Plus, Apexit Plus, and GuttaFlow Bioseal sealer to root dentin.Materials and Methods:After decoronating sixty extracted single-rooted premolar teeth, preparation was done using ProTaper Gold rotary files until F3. The samples were randomly divided into three groups (n = 20 each) consistent with the sort of sealer used for obturation. After obturation with lateral compaction technique, half of the samples (n = 10 each) were sectioned transversely for measuring tubular depth penetration under a confocal laser scanning microscope. Longitudinal sections were obtained for the rest half the samples to gauge the difference of sealer using the scanning electron microscope.Statistical Analysis Used:Data were analyzed using one-way analysis of variance and Tukey's post hoc tests.Results:GuttaFlow Bioseal has shown a significantly higher depth of sealer penetration and minimum interfacial adaptation than resin-based sealer and calcium hydroxide-based sealer (P < 0.05).Conclusion:At all root regions, the GuttaFlow Bioseal sealer exhibited more sealer penetration and minimum interfacial adaptation whereas the Apexit Plus sealer exhibited less sealer penetration and maximum interfacial adaptation.

A Cross-Sectional Study on the Preference of Root Canal Sealers Among Pediatric Dentists For Obturating Permanent Teeth

Utilisation of root canal sealers to perform obturation procedures is an endorsed method in endodontics and has an indispensable role in the success of treatment. The objective of this study was to explore the pediatric dentists’ preference for root canal sealers for obturating permanent teeth. 360 permanent teeth with gutta-percha obturation done by pediatric dentists were analyzed for the study. The variety of root canal sealers that are utilised for obturating the permanent teeth by pediatric dentists were assessed. The data were obtained from a patient management software. Chi-square test was performed. Out of the 360 permanent teeth, 186 teeth were obturated using resin-based sealers, 101 teeth using zinc oxide eugenol-based sealers and 73 teeth were obturated using calcium hydroxide-based sealers, with statistically significant difference between the three materials (P&lt;0.05). Based on the findings of the present study, resin sealers followed by zinc oxide eugenol sealers and calcium hydroxide sealers were more preferred by pediatric dentists for root canal therapy in permanent teeth.

Long-Term Impact of New Calcium-Silicate-Based Sealer on Mineral Contents and Crystallinity of Radicular Dentin: An Ex Vivo Study

Introduction. This study aimed to evaluate the long-term impact of new calcium silicate-based sealer (HiFlow Bioceramic) compared to calcium hydroxide-based sealer (Sealapex) on mineral constituents and crystallinity of radicular dentin. Methods. Roots of multirooted maxillary molars were denuded their dentin from all covered cementum then longitudinally split. The dentin segments were divided into three groups covered with either HiFlow root canal sealer or Sealapex root canal sealer or kept untreated (control group). After complete setting of sealers, the radicular dentin of each group was stored in phosphate buffer solution or deionized water for 60 days and then examined with Fourier Infrared Spectroscopy, scanning electron microscope/energy dispersed X-ray and X-ray diffraction (XRD). Results. When the dentin was stored in phosphate buffer solution, compared with untreated dentin, Fourier transform infrared spectra showed insignificant increase in the amide I and phosphate, significant increase in carbonate area, and carbonate/phosphate ratio, while there was insignificant change in phosphate/amide I ratio of HiFlow-treated dentin, whereas Sealapex induced significant decrease in amide I area, phosphate area, and phosphate/amide ratio. Both sealers induced significant increase in crystallinity index and significant decrease in crystallinity percent. Energy dispersed X-ray showed decrease in calcium content by both sealers. The phosphate content was increased by HiFlow and decreased by Sealapex. Conclusions. The mineral composition and crystallinity of dentin were insignificantly changed by the long-term HiFlow treatment, whereas, markedly changes by Sealapex.

Perbedaan Daya Antibakteri Antara Kombinasi Calcium Hydroxide-Based Sealer-Amoxicillin Dan Resin-Based Sealer-Amoxicillin Terhadap Bakteri Enterococcus Faecalis

Background. About 24-77% of root canal treatment failure cases are caused by infection of Enterococcus faecalis due to the resistance factor and virulence of these bacteria. Calcium hydroxide-based sealer and resin-based sealer are two types of sealer often used for root canal obturation due to their antibacterial properties. But the antibacterial properties owned by calcium hydroxide-based sealer has no effect on Enterococcus faecalis. Therefore, the adjunct of local antimicrobial such as amoxicillin is needed to increase antibacterial activities of root canal obturation materials (sealers) especially for calcium hydroxide-based sealer. Purpose. The aim of this study was to compare the effectiveness of antibacterial activity of calcium hydroxide-based sealer-amoxicillin and resin-based sealer-amoxicillin against Enterococcus faecalis. Methods. This study is an experimental laboratory with post test only control group design using Enterococcus faecalis ATCC 29212. Agar diffusion test was used to check the antimicrobial activity of calcium hydroxide-based sealer-amoxicillin and resin-based sealer-amoxicillin. by measuring the inhibition zone diameter of each treatment. Results. Resin-based sealer-amoxicillin’s diameter of zone inhibition is 37,3 mm and calcium hydroxide-based sealer-amoxicillin’s diameter is 18,7 mm. Conclusion. Antibacterial activity of resin-based sealer-amoxicillin is significantly greater than calcium hydroxide-based sealer-amoxicillin.

Evaluation of Selective Physicochemical and Biological Properties of Different Root Canal Sealers.

This in vitro study aimed to evaluate the chemical composition, water solubility, radiopacity, pH, electrical conductivity and cytotoxicity of four different root canal sealers. Four materials were tested including an epoxy resin-based sealer (AH-Plus), a calcium silicate-based sealer (MTA Fillapex), a calcium hydroxide-based sealer (Sealapex) and a zinc-oxide-eugenol-based sealer (Endofill). The materials were submitted to energy-dispersive x-ray microanalysis for elemental chemical composition. Solubility and radiopacity were evaluated according to ANSI/ADA. The pH and electrical conductivity were measured at different periods of time. L929 immortalized mouse fibroblast line were used for cytotoxicity evaluation. Statistical analyses were carried out using the ANOVA and Tukey's test. The main elements were found to be silicon and calcium in MTA Fillapex, calcium and bismuth in Sealapex, zirconium and tungsten in AH-Plus and zinc and bismuth in Endofill. Sealapex had the highest value for solubility (P<0.05), AH-Plus showed the highest radiopacity value (P<0.05) while MTA Fillapex had the highest pH and electrical conductivity values (P<0.05). AH-Plus showed the highest rate of cell viability (P<0.05). Based on the results of this in vitro study, it was possible to conclude that Endofill and Sealpex did not meet the requirements for water solubility. The tested sealers were alkaline and showed radiopacity in accordance with ANSI/ADA standards. AH-Plus showed to be less cytotoxic than other tested root canal sealers.

Effect of Time of Interradilarcular Preparation on Apical Microleakage of Endodontically Treated Teeth

Purpose: This study was conducted to evaluate apical leakage of post space preparation when performed at different time intervals immediately after root canal obturation (after setting of the sealer used) or delayed after two weeks. Materials and methods: Forty-five extracted human anterior single rooted teeth were selected and placed in sterile physiologic saline solutions. Teeth were decoronated perpendicular to their long axis and 2mm above the cemento-enamel junction (CEJ). The canals were filed to mater apical file size #40 using step-back tech. The root canals were enlarged and flared to size #55. The specimens were divided randomly into 3 equal groups(15 samples each) , according to type of sealer that used during root canal treatment group (1) Eugenol-based sealer, group(2) Calcium hydroxide-based sealer and group (3) Resin –based sealer, After root canal obturation, the specimens were further subdivided into three subgroups (5 samples each): subgroup (A) without post space preparation as control, Subgroup (B) with immediate post space preparation and Subgroup (C) with delayed post space preparation. Results: Calcium hydroxide based sealer group recorded the highest mean value of apical leakage followed by Zinc oxide eugenol-based sealer and AD SEAL resin based sealer which recorded the lowest mean value with no statistical significant difference (P˃0.05). Regarding the effect of time interval control sub group recorded the statistically significant lowest mean value followed by immediate subgroup, while delayed subgroup recorded the statistically significant highest mean value (P ˂0.05). Conclusions: The type of sealer had major effect on the apical seal of endodontically treated teeth. Post-space preparation affects the apical seal of endodontically treated teeth. The effect of immediate preparation on apical seal was significantly lesser than delayed post space preparation.

Comparative Evaluation of Antibiofilm Efficacy of Chitosan Nanoparticle- and Zinc Oxide Nanoparticle-Incorporated Calcium Hydroxide-Based Sealer: An In vitro Study.

Aim:This study evaluated the antibiofilm efficacy of calcium hydroxide-based sealer incorporated with chitosan nanoparticles (CS-NPs) and zinc oxide nanoparticles (ZnO-NPs) against two strains of Enterococcus faecalis (ATCC 29212, OG1RF).Materials and Methods:The materials tested were Apexit Plus sealer in the commercial unmodified form and two modified forms with CS-NP and ZNO-NP, respectively. Crystal violet assay and confocal laser scanning microscopy (CLSM) study were used to assess the bacterial viability of biofilms grown in wells of microtiter plate and glass slides, respectively. Two E. faecalis strains (ATCC 29212, OG1RF) were used for the study.Results:The crystal violet assay done on E. faecalis strain ATCC 29212 showed a significant decrease in the optical density (OD) value with ZNO-NP-incorporated calcium hydroxide sealer when compared with CS-NP. In the case of E. faecalis strain OG1RF, only ZNO-NP-incorporated calcium hydroxide-based sealer showed reduction in the OD value. In CLSM study done on E. faecalis strain ATCC 29212, only ZNO-NP-incorporated calcium hydroxide-based sealer showed reduction in the thickness of biofilm. No groups of OG1RF strain showed reduction in the thickness of biofilm.Conclusion:The incorporation of nanoparticles (ZnO and CS) into calcium hydroxide-based sealers significantly enhances the antibiofilm efficiency against E. faecalis strain ATCC 29212 but has questionable effectiveness against E. faecalis strain OG1RF. The present study demonstrates that ZNO-NP shows better antibiofilm efficacy than CS-NP against both strains of E. faecalis.

Biological and physico-chemical properties of new root canal sealers.

BackgroundThe purpose of the present study was to compare the biological and the physico-chemical properties of bioceramic-based root canal sealers, calcium hydroxide-based, MTA-based and epoxy resin-based root canal sealers.Material and MethodsTwo bioceramic-based sealers, one calcium hydroxide-based sealer, one MTA-based sealer and two epoxy resin-based sealers were tested.ResultsEasySeal and MTA Fillapex showed severe citotoxic activity, AH Plus and SealapexTM moderate cytotoxicity, BioRoot™ RCS and TotalFill BC Sealer were both cytocompatible. Except for TotalFill BC Sealer, all root canal sealers caused inhibition zones when tested with E. faecalis. The highest inhibition zone was observed for EasySeal, followed by AH Plus. BioRoot™ RCS, SealapexTM and MTA Fillapex showed the lowest inhibition zone. All the tested materials showed different degree of antibacterial activity by using direct contact test (DCT). The highest values were observed for BioRoot™ RCS, TotalFill BC Sealer and EasySeal, followed by MTA Fillapex and SealapexTM. Except for BioRoot RCS and TotalFill BC Sealer, all the root canal sealers fulfilled the requirements of the ISO 6876 standard, demonstrating a weight loss less than 3%. Bioroot RCS, TotalFill BC Sealer and SealapexTM exhibited high alkaline pH with an increase both for BioRoot™ RCS and TotalFill BC Sealer after 24 hours.ConclusionsThe new bioceramic-based sealers showed acceptable physico-chemical properties, but BioRoot™ RCS and TotalFill BC Sealer seems to be too soluble, not respecting ISO 6876 requirements. Key words:Antibacterial activity, cytoxicity, pH, root canal sealers, solubility.

Comparative Evaluation of Cytotoxicity of Root Canal Sealers on Cultured Human Periodontal Fibroblasts:In vitroStudy

To evaluate and compare the cytotoxic effects of different types of root canal. The sealers were eluted with culture medium for 1 hour, 7 days, and 14 days. Cell viability was estimated by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and trypan blue exclusion method on human periodontal ligament (PDL) fibroblast cells. Sealers used are mineral trioxide aggregate (MTA)-based sealer (MTA Fillapex, Angelus), calcium hydroxide-based sealer (Apexit Plus, Ivoclar Vivadent), resin-based sealer (AH Plus, Dentsply), and zinc oxide eugenol-based sealer (Tubli Seal, SybronEndo). The order of cytotoxicity through MTT assay, at the end of the second week, was observed as MTA Fillapex> Tubli Seal> Apexit Plus > AH Plus. The percentage cell viability obtained after trypan blue exclusion method decreased in the order of Apexit Plus> Tubli Seal> AH Plus> MTA Fillapex, which was similar to the reported cytotoxicity from the MTT assay after 1 hour. Each type of sealer showed moderate-to-severe cytotoxic response when compared with the control. The MTA Fillapex was found to be the most cytotoxic sealer. Use of resin-based material as a root canal sealer may result in a more favorable response to PDL fibroblasts. Having knowledge of the cytotoxicity of various sealers will help in increasing patient's comfort.

Antimicrobial Efficacy of Different Endodontic Sealers against Enterococcus faecalis: An In vitro Study.

ObjectiveThe aim of this in vitro study is to compare the antimicrobial efficacy of four different endodontic sealers against Enterococcus faecalis.Material and Method:Four different endodontic sealers, namely, resin based (AH Plus), zinc oxide-eugenol based (Tubliseal), calcium hydroxide based (Sealapex), and mineral trioxide aggregate (MTA Fillapex) based were tested for their antimicrobial efficacy against E. faecalis using agar diffusion method. Four wells were made by the removal of agar at equidistant points and filled with freshly mixed respective root canal sealers and were inoculated with E. faecalis. All the three plates were incubated for a period of 72 h at 37°C under aerobic conditions. The diameter of inhibition zones was measured at 24, 48, and 72 h time intervals. Data obtained were statistically analyzed using one-way analysis of variance and unpaired t-test.Results:All the tested sealers showed some bacterial growth inhibition of E. faecalis. Their efficacy in descending order of antibacterial activity was as follows: Sealapex > AH Plus > Tubliseal > MTA Fillapex. The efficacy of the root canal sealers decreased marginally with increase in their duration of action.Conclusion:Antimicrobial efficacy of calcium hydroxide-based sealer was highest followed by resin-based sealer and was the least with MTA based sealer.

Biocompatibility of Calcium Hydroxide - Based Root Canal Sealers: A Histological Study

Biocompatibility has been defined as the ability of a material to function in a specific site, in contact with host tissues but without inducing any undesirable local or systemic reaction.The aim of this study is to evaluate the biocompatibility of calcium hydroxide-based endodontic sealers and to compare it with a resin-based material, by measuring the degree of inflammation induced by these products after subcutaneous implantation in rats. We used 12 animals divided in 3 study groups and 1 control group; implants with Mineral Trioxide Aggregate (MTA), AH26 and Sealapex were placed in subcutaneous tissue and histological evaluation was carried out after 7, 14 and 21 days. We obtained comparable results between MTA and Sealapex, which demonstrates that these materials have similar degrees of biocompatibility. Based on this experimental study, calcium hydroxide containing cements express similar biocompatibilities. Further clinical studies are necessary in order to evaluate the healing properties and apical seal of these materials.

혼합 직후 또는 경화된 근관용 실러의 한천중층시험

This study was performed to evaluate the cytotoxicity of root canal sealers before and after setting procedures by an agar overlay test. Six kinds of root canal sealers were used in this experiment: AH Plus, AH 26, ADSEAL, DIA-PROSEAL, Tubli-Seal, and Sealapex. Test materials were prepared as either freshly mixed type of provided components or hardened specimens after setting procedures in each Teflon ring-shaped holder. Agar overlay test was done with L929 mouse fibroblast cells and positive, negative and test materials were set on the solidified agar medium. After 24 hrs, decolorization index and lysis index were evaluated and its cell response was interpretated. Decolorization zones and lysis values by all root canal sealers used in this study showed index 5 when freshly mixed root canal sealers were placed. Decolorization zones by AH Plus and AH 26 were larger than those by other two kinds of resin sealers after setting procedures. Zinc oxide eugenol-based sealer, Tubli-Seal, showed decolorization index 3 and lysis index 5, otherwise, calcium hydroxide based-sealer, Sealapex, did decolorization index 2 and lysis index 4 after hardening procedures. Among test materials, DIA-PROSEAL had the least cytotoxicity after hardening, followed by ADSEAL and Tubli-Seal. In conclusion, all root canal sealers had the severe cytotoxic effects when freshly mixed materials were tested. However, cytotoxicity was reduced after sealer hardening, especially in case of DIA-PROSEAL.

Antibacterial efficacy of three root canal sealers against Enterococcus faecalis and Candida albicans: An in vitro study

Aim: The aim of this in vitro study was to compare the antimicrobial efficacy of calcium hydroxide-based sealer (Apexit Plus), zinc oxide eugenol-based sealer (Endoflas FS) and resin-based sealer (EndoRez) root canal sealers against Enterococcus faecalis microbial type culture collection (MTCC) 439 and Candida albicans MTCC 239 using agar diffusion test. Materials and Methods: In the present study, 20 Mueller Hinton agar (MH agar) plates were employed. Three wells were made by removal of agar at equidistant points and filled with root canal sealers according to manufacturer's instructions. The strains of the bacteria and fungi used in this study were E. faecalis MTCC 439 and C. albicans MTCC 227. Both micro organisms were grown at 37°C for 24 h in MH Broth and seeded into MH agar to produce a turbidity of 0.5 on the McFarland scale, which corresponds to a concentration of 10 8 CFU/mL. This MH broth was used as a second layer. The seeded agar was then added over the plates immediately after the insertion of sealer cements. After incubation, the diameters of zones of inhibition around the plates were measured. Results: The results were statistically analyzed using two way ANOVA test. Against both the micro organisms used in this study, Endoflas FS showed the largest zones of inhibition followed by Apexit Plus and EndoRez. Conclusion: Within the limitations of this study, it can be concluded that: Root canal sealers showed different inhibitory effects depending on their types and microbial strains tested. Against Enterococcus faecalis and Candida albicans, zinc oxide based sealers showed the highest microbial zones of inhibition followed by the calcium hydroxide based sealer and resin based sealer respectively

Retention of fiber posts to the optimally and over-prepared dowel spaces

PURPOSETo assess the retention of glass fiber post cemented with self-adhesive resin cement into optimum and over-prepared root canals following obturation in the presence of either eugenol (EB) or calcium hydroxide (CB)-based sealers.MATERIALS AND METHODSRoots of extracted premolars were endodontically-treated in 5 groups (n = 10). Roots of Group 1 (control) were left with no obturation and then optimally prepared to receive endodontic dowels. Other root canals were obturated with gutta-percha in the presence of either eugenol-based (Groups 2 and 4) or calcium hydroxide-based (Groups 3 and 5) sealer. Dowel spaces were prepared with optimal diameter in Groups 2 and 3, one size larger in Groups 4 and 5. Standardized fiber posts were luted to the prepared spaces using self-adhesive resin cement and itsretention was then tested on an universal testing machine. Both one-way ANOVA and Tukey's HSD comparisons (α=0.05) were used to identifythe significance of inter-group retention differences. Scanning electron microscopy (SEM) of both optimally and over-prepared dowel spaces was also considered to figure the nature of their interior out.RESULTSThe post retention was significantly higher to the non-obturated, optimally-prepared dowel spaces of Group 1 compared to the obturated, optimally-prepared ones of Groups 2 and 3. For each dowel space diameter, root canals obturated using CB of Groups 3 and 5 showed significantly higher dowel retention compared to those obturated using EB of Groups 2 and 4. Post retention to the over-prepared dowel spaces of Groups 4 and 5 was significantly higher than that recorded for the optimally-prepared ones of Groups 1-3. SEM images revealed traces of endodontic sealer and gutta-percha on the walls of the optimally-prepared dowel spaces.CONCLUSIONDespite the adverse effect of endodontic sealers on the retention of fiber posts, the over-preparation of dowel spaces helps to improve the retention.