Bond Strength Of Endodontic Sealers Research Articles

Root canal filling quality and bond strength of endodontic sealers to human and bovine dentin

Objective: This study aimed to compare the filling quality and bond strength of two endodontic sealers, AH Plus and Bio-C Sealer, in human and bovine teeth. Methods: The root canals of 60 [30 human (H) and 30 bovine (B)] single-rooted teeth were prepared and filled by lateral condensation of gutta-percha and AH Plus (groups AP-H and AP-B) or Bio-C Sealer (groups BC-H and BC-B). Six 1.5-mm-thick slices were obtained from each root. The specimens were observed under a stereomicroscope to assess filling quality, considering possible voids within the filling material. Subsequently, root slices were evaluated in terms of push-out bond strength and failure mode. Data were analyzed by Mann-Whitney tests and Spearman correlation coefficients (α=5%). Results: The filling quality provided by AP and BC was similar in both dentin substrates. However, when comparing human and bovine teeth, void scores were greater in the bovine samples, for both sealers. AP had higher bond strength to human and bovine dentin than BC. However, there was no significant difference in bond strength between dentin substrates, for both sealers tested. Also, there was a positive and moderate correlation between the bond strength values of human and bovine teeth. The mixed failure mode was the most prevalent. Conclusion: AP and BC provide similar filling quality, but the first presents higher bond strength values to human and bovine dentin. The use of bovine teeth as substitutes for human samples seems adequate in studies related to bond strength, but not in those testing root canal filling quality.
 Keywords: Dentin, Endodontics, Root canal filling materials.

Influence of antimicrobial photodynamic therapy on the bond strength of endodontic sealers to intraradicular dentin: A systematic review and meta-analysis.

The objective of this systematic review and meta-analysis (SRMA) was to investigate the influence of antimicrobial photodynamic therapy (aPDT) on the bond strength of endodontic sealers to intraradicular dentin. This SRMA followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the International Prospective Registry of Systematic Reviews (PROSPERO) (CRD42022319856). A population, intervention, control, and outcome (PICO) question was formulated: "Does antimicrobial photodynamic therapy decrease the bond strength of root canal sealers?". A literature search was performed in PubMed/MEDLINE, Embase, Web of Science, Scopus, Cochrane Library, and ProQuest databases until July 2022. Joanna Briggs Institute Critical Assessment Guidelines for Quasi-Experimental Studies were used for quality assessment. The meta-analysis was based on the inverse variance (IV) method (p<0.05). Out of an initial 345 articles, 8 in vitro studies were included, published between 2013 and 2022. The studies were qualitatively analyzed; two studies showed a positive effect, two studies a negative effect, and the other studies showed no effect on bond strength of endodontic sealers to intraradicular dentin. Seven of the studies were included in the SRMA, which indicated that there was no significant difference in bond strength when using aPDT (P=0.90; MD: -0.03; 95% CI: -0.46 to -0.41). There was a high level of evidence for each meta-analysis outcome. It can be concluded that the use of aPDT as a method of root canal disinfection does not negatively influence the bond strength of endodontic sealers in the root canal.

Comparison of push-out bond strength of endodontic sealers after root canal drying with different techniques.

An ideal endodontic sealer should bond to both dentin and root-filling material. This study aimed to assess the push-out bond strength (PBS) of mineral trioxide aggregate(MTA)-Fillapex, Endoseal MTA, AH26, and Sure-Seal Root to root dentin after root canal drying with different techniques. This in vitro study was conducted on 160 extracted mandibular premolars. After root canal preparation, the teeth were randomly divided into four groups (n = 40) of drying with ethanol, paper point, air vacuum, and control (wet canal). Each group was divided into four subgroups (n = 10) for use of AH26, Sure-Seal Root, MTA-Fillapex, and Endoseal MTA sealers. The mean PBS was measured by a universal testing machine. The mode of failure was determined under a stereomicroscope. Data were analyzed by the Kruskal-Wallis and Games-Howell tests. The maximum mean PBS was equally recorded in ethanol and paper point groups, and was significantly higher than that of control and air vacuum groups (p < .001). In the use of AH26 sealer, the mean PBS in drying with ethanol was significantly higher than all other methods (p < .05). The mean PBS in drying with a paper point was also significantly higher compared with control and air vacuum methods (p < .05). In the use of Sure-Seal, the mean PBS in drying with a paper point was significantly higher than other methods (p < .05). The mean PBS in drying with ethanol was significantly higher than that in control and air vacuum methods (p < .001). In the use of MTA-Fillapex and Endoseal-MTA,the technique of drying had no significant effect on PBS. Adhesive and mixed failures were the most common in all drying groups. Drying with ethanol and paper point enhanced the PBS of sealers to root dentin.

Effects of calcium hydroxide intracanal medicament on push-out bond strength of endodontic sealers: A systematic review and meta-analysis.

To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers. A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value <0.05. A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD=0.03; 95% CI=-0.55, 0.60; p=0.93), and calcium silicate-based group (SMD=0.02; 95% CI=-0.31, 0.35; p=0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias. The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers. The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

Influence of root canal moisture conditions on the bond strength of endodontic sealers to dentin

Objective: To investigate the influence of intraradicular moisture conditions on the bond strength of 3 different endodontic cements in the coronal, middle, and apical thirds of the root canal. Materials and Methods: 90 single-rooted teeth were instrumented with a reciprocal R#50 file and randomly divided into 3 experimental groups: Dry group: dry canals with absorbent paper tips; Moist group: suction syringe and capillary tip coupled to a vacuum pump; Wet group: aspiration with endodontic suction. The groups were divided according to the endodontic sealer used: AH plus (Denstply), Hiflow (Brasseler) and Bio-c Sealer (Angelus). Obturation was performed using Tagger's hybrid technique with a single cone. The teeth were subjected to the "push-out" test to evaluate the bond strength of the cements. Results: Data were analyzed using the Kolgomorov-Smirnoff normal distribution test and the Mann Whitney U test to compare means within and between groups. The standard error established was 5% at a significance level of 95%. AH plus showed better results regardless of canal moisture conditions. Hiflow showed better bond strength in the dry group compared to the moist group (p=0.023) in the cervical area. Bio-C Sealer showed no statistically significant differences (p &gt; 0.05). Conclusion: Moisture conditions affected the bond strength values of endodontic cements. The prevalence of failure moduli was mixed in all root thirds, regardless of the cement used.

The effect of four different intracanal medicaments on the push-out bond strength of root canal sealers.

This study aimed to compare the effect of 4 different intracanal medicaments on the push-out bond strength of two sealers (AH Plus and MTA Fillapex). 100 single-rooted extracted premolar teeth were divided into 5 groups, with 20 samples in each group, one group being the control group. After cleaning and shaping procedures, the canals were filled with 4 different medicaments: calcium hydroxide, tri-antibiotic paste (TAP), Metapex, or Chlorhexidine (2%) gel for 2 weeks. Following this, the medicaments were rinsed away, and the samples in those sub-groups were obturated with gutta-percha/AH Plus or MTA Fillapex sealers. After 2 weeks of incubation, a 2-mm-thick middle section from each root was evaluated to test push-out strength. The obtained data were tabulated, and appropriate statistical analysis was performed (two-way ANOVA and LSD test). When comparing the average values, the bond strength values of AH Plus were significantly higher than those of MTA Fillapex (p<0.05) in all medicament groups. Based on the findings, we concluded that AH Plus had comparatively higher bond strength than MTA Fillapex. We also observed that AH Plus had higher bond strength in the presence of calcium hydroxide, whereas MTA Fillapex in the presence of Chlorhexidine. A comparison of the push-out bond strength shows that irrespective of the root canal segment or the final irrigant used, AH Plus showed higher values among all groups. The limitation of the current study was that the effect of TAP on the bond strength of endodontic sealers was not negative.

The influence of different root canal irrigants on the push-out bond strength of AH plus and Bioceramic sealers

Background: The bond strength of endodontic sealers with dentin is a very important property for maintaining the integrity and seal of the root canal filling. The aim of this study was to evaluate and compare the effect of various irrigants (QMix, 17% EDTA and 2.5% NaOCl) on the push-out bond strength of AH plus and Bioceramic sealers. Materials and methods: Forty eight freshly extracted maxillary first molars human teeth with striaght palatal root were used in the study. The collected samples were randomly divided into three groups of equal sample size (n=16), according to the final irrigation regimen as follows: Group (1): QMix 2 in 1, Group (2): 17% ethylenediaminetetraacetic acid, Group (3): 2.5% sodium hypochloride. All samples were instrumented using Edge file X7 rotary instrument reaching file size 40/.04 as the final master apical file. After that each group was randomly divided into two subgroups (n=8) according to the type of sealer used: AH Plus and Total Fill BC Sealer. Obturation was conducted using single cone technique with gutta percha (GP) to all experimental roots. Two-millimeter thick slices were obtained from the middle section of the root. Bond strength of sealers was measured via a universal testing machine by using stainless steel plunger. Then, the data were statistically evaluated using two-way analysis of variance (ANOVA) and post hoc test (Bonferroni’s test). Results: The push-out bond strength was significantly increased by the “irrigant” factor (P≤0.05) and by “sealer/irrigation solution” interaction (P≤0.05). Final rinse with QMix solution with BC sealer showed the highest mean value of bond strength (5.976 MPa), with a significant difference with other groups (P≤0.05), while NaOCl with AH Plus sealer showed the lowest mean value of bond strength (3.811 MPa). Conclusion: Final irrigation of the root canals with different irrigants improved the endodontic sealer's bond strength, and QMix had a positive influence on the adhesion of BC sealer.

The effect of Erbium-doped Yttrium Aluminum Garnet laser irradiation on push-out bond strength of endodontic sealers with root canal dentin: An in vitro evaluation of push-out bond strength and failure modes

Objectives: The aim of this study was to evaluate and compare the push-out bond strength of bioceramic sealer and resin-based sealer on Erbium-doped Yttrium Aluminum Garnet (Er:YAG) treated root canals. Material and Methods: Sixty single-rooted teeth were collected, decoronated apical to the cementoenamel junction, maintaining the minimum root length of 14 mm. Samples were instrumented with WaveOne Gold primary file and divided into two experimental groups (n = 30), based on laser irradiation: Group I: No laser and Group II: Er:YAG laser irradiated. Groups I and II were again divided into two subgroups “a” (AH Plus) and “b” (mineral trioxide aggregate [MTA] Fillapex) with 15 samples in each group. As per the grouping, sealers were coated onto the canal walls and obturated. After 24 h of storage in 100% humidity at 37°C, all the samples were sectioned transversely and push-out test was performed using universal testing machine. Stereomicroscope was used to determine the mode of failure. A one-way analysis of variance was employed to compare the mean POBS. Kolmogorov–Smirnov and Shapiro–Wilk parametric tests were done to check the normality. The Games-Howell multiple post hoc test was used for pairwise comparison of the groups at a 95% confidence level. Results: Both AH Plus and MTA Fillapex exhibited higher bond strength in the laser-treated canals. AH plus exhibited superior bond strength compared to MTA Fillapex in both laser and non-laser-treated groups (P &lt; 0.05). AH Plus groups have predominantly presented cohesive failure whereas MTA Fillapex presented mixed failures. Conclusion: Irradiation with Er:YAG laser in the root canal before obturation improves the bond strength significantly. The adhesive properties of MTA Fillapex are comparable to that of AH Plus.

Effect of Gutta-percha Solvents on the Bond Strength of Sealers to Intraradicular Dentin: A Systematic Review.

The aim of our systematic review was to assess the impact of gutta-percha solvents on the bond strength of endodontic sealers to intraradicular dentin using the push-out bond test. The literature was searched in databases (PubMed, Web of Science and Scopus) up to September 2020, using the following search terms: (bond strength AND solvent* AND sealer* AND (tooth root OR dentin OR retreatment OR root canal). No date limits were implemented, and English languages were included. The question research was constructed based on the PICO (Population, Intervention, Comparison, and Outcome) strategy: "Does gutta-percha solvents effect the bond strength of sealers to intraradicular dentin?". The studies were analyzed by two reviewers and were included if they utilized extracted permanent human teeth with completely formed apices, as well as assessed the influence of gutta-percha solvents on the bond strength of sealers to intraradicular dentin using push-out bond test. Review articles, case reports and studies that included immature, bovine or artificial teeth were excluded. The risk of bias was evaluated based on the Cochrane criteria adopted to in vitro studies. Thirty-two papers were analyzed, seven accomplished the eligibility criteria and were selected for our systematic review. The global risk of bias was high. Due to variations in the methodological variables, a meta-analysis could not be performed. Our systematic review highlighted the adverse effect of chloroform, which decreased the bond strength of different sealers, and the generally higher bond strength of epoxy resin-based sealers, detected with the push-out bond test. We recommend the standardization of methods in future studies to obtain a more definitive conclusion about the influence of solvents on the bond strength of sealers to intraradicular dentin.

Bond Strength of Endodontic Sealers to Gutta Percha and Dentin

Aims: The aims of present study were to compare shear bond strength (SBS) and push-out bond strength (PBS) of three types of sealers to gutta percha (G) and dentin (D) and to assess failure modes at debonded interfaces. Materials and Methods: Sealers tested were AH Plus, Sealer 26, and Endofill. In PBS, 30 mandibular premolar decoronated and instrumented with rotary ProTaper to F3 then teeth were divided into 3 groups (10 teeth in each) and obturated with F3 proTaper G and one of tested sealer, 1mm mid root slices were prepared for PBS test. In SBS/D, 30 root cylinders 7 mm length were embedded horizontally in resin then root surfaces were flattened and smooth. In SBS/G, 30 G cylinders were embedded in a resin. In both SBS tests, specimens were divided into three groups, 10 samples each then polyethylene tubes positioned on polished specimens (prepared for SBS/D and SBS/G) filled with one of the tested sealer. All BS tests were performed on digital universal testing machine. Collected data analyzed statistically using one way ANOVA and Tukey test. Results: PBS, SBS/D, and SBS/G for AH Plus significantly higher than Sealer 26 and Endofill. Also Sealer 26 exhibited significantly higher bond strength than Endofill. Predominance mode of failures were adhesive and mixed. Conclusions: According to the finding of present study, it can be concluded that the AH Plus for root canal therapy produce better results in endodontic. PBS and SBS were sufficient tests to measure bond strength of root canal sealers to G and D.

Evaluation of the effect of endodontic chelating solutions on push out bond strength of endodontic sealers (An in-vitro study)

Aim: This study was carried out to evaluate the effect of various chelating solutions (EDTA-Apple Vinegar-Sodium Hypochlorite)on the radicular push-out bond strength of zinc oxide nanosealer and AH Plus resin based rootcanal sealer. Materials and Methods: 180 extracted single-rooted human teeth with complete roots, fully formed apices were used in this study,on completion of instrumentation, the specimens will be randomly divided into three groups (n=60) according to chelating solution applied: Group ( I ) 1.5 mL of 17% EDTA (pH = 7), Group ( II ) 2.5 mL of vinegar apple and Group ( III ) 2 mL of 5.25% sodium hypochlorite (NaOCl). These groups are subdivided into two subgroups (n=30) each according to root canal sealer used: Subgroup A: AH Plus and Subgroup B: Zinc oxide nanosealer. Then the specimens in the subgroups will be further randomly divided into two groups (n=15) according to storage time: Subgroup 1:one week storage time and Subgroup 2: one month storage time The root canals were prepared using ProTaper rotary instruments up to master apical rotary size F3 (#30), in conjunction with 2 mL of Normal saline solution (Sodium Chloride 0.9%) irrigation between each file and the chelating solution was applied for 1 minute then final rinse with distilled water. The sealers were loaded and introduced to the canal using K file size40.Testing push-out bond strength was done for all samples using the Intrson universal testing machine. Results: It was found that the highest push-out bond strength mean value recorded for (EDTA+ AH Plus) (1 week) group (IA1) (3.424 MPa) followed by (Apple Vinegar+ AH Plus) (1 week) group (IIA1) (1.263 MPa) while the lowest mean value recorded for (NaOCl+ZnO nanosealer) (1 month) group (IIIb2) (0.575 MPa). The difference between different groups was statistically significant as revealed with one way ANOVA test (p 0.05) differences between {(Apple Vinegar+AH Plus) and (NaOCl +AH Plus) (1 week)}, {( EDTA+ AH Plus), (Apple Vinegar+ AH Plus) and(NaOCl+ AH Plus) (1 month)}, {(EDTA+ ZnO nanosealer) and (NaOCl+ ZnO nanosealer) (1 month)}. Conclusions: AH Plus sealer had the highest push-out bond strength when used with EDTA, ZnO nanosealer had the highest push –out when used with apple vinegar and all AH Plus subgroups had higher push-out bond strength than ZnO nanosealers subgroups

Effects of different intra canal medicaments on the push out bond strength of endodontic sealers.

BackgroundOne of the essential properties of the root canal sealers is the adhesion to root canal dentin and their higher bond strength decreases the microleakage. The aim of the present study was to compare the effect of Different Intracanal medicaments on the push out bond strength of AH26 and MTA Fillapex sealers.Material and MethodsA total of 104 one-rooted extracted human teeth were divided into 4 (n=26) experimental groups. After the cleaning and shaping, the root canals were filled with Ca(OH)2, triantibiotic paste (TAP), Metapex or 2% chlorhexidine gel for two weeks. Then, intracanal medicaments were rinsed away and the samples in the sub-groups were obturated with gutta-percha and AH26 or MTA Fillapex sealers. After two weeks incubation, 2-mm-thick middle section of each root was then subjected to push-out testing. Data were analyzed with two-way ANOVA and LSD test.ResultsWith all the intracanal medicaments, the overall mean of bond strength values were significantly higher with AH26 compared to MTA Fillapex (p<0.05). With the use of MTA Fillapex the maximum and minimum means of bond strength values were recorded with CHX and Metapex and for AH26 were recorded with Ca(OH)2 and chlorhexidine, respectively.ConclusionsThe bond strengths of sealers to dentin are under the influence of pre-treatment with intracanal medicaments. Under the limitations of the present study, the effect of TAP on the bond strength of endodontic sealers was not negative. Key words:AH26, medicament, MTA Fillapex, push-out bond.

Do smear-layer removal agents affect the push-out bond strength of calcium silicate-based endodontic sealers?

To evaluate the effect of 17% ethylenediaminetetraacetic acid (EDTA), 2.25% peracetic acid (PA) or 10% citric acid (CA) on the push-out bond strength of calcium silicate-based endodontic sealers [MTA Fillapex (Angelus, Londrina, Brazil) and Total Fill BC Sealer (FKG, La Chaux-de-Fonds, Switzerland)] to root dentine after different periods of immersion in phosphate-buffered saline (PBS). AH Plus (Dentsply DeTrey, Konstaz, Germany) was used as a reference material for comparison. Thirty human maxillary incisors were selected and three 1-mm discs were obtained from the middle third of each root. On the axial surface of each disc, three 0.8-mm-diameter holes were drilled through the dentine. After standardized irrigation, each dentine disc from the same root was treated for smear-layer removal with one of the three tested chelating solutions: EDTA, PA or CA. After that, the holes were dried with paper points and filled with one of the three test root canal sealers. The filled dental slices were further immersed in PBS solution (pH 7.2) for 7days (T1) or 30days (T2) at 37°C, before the push-out assay. Friedman, Kruskal-Wallis and Mann-Whitney tests were used respectively to estimate the impact of the independent variables (solutions, sealers and period of PBS immersion) on the push-out bond strength. The level for significance was set at α=5% and data were further subjected to a Bonferroni correction. Solutions and periods of immersion did not significantly influence the displacement resistance (P=0.285, and P=0.104, respectively) of sealers to root dentine. On the other hand, the type of sealer significantly affected the push-out bond strength (P=0.000). AH Plus was associated with greater resistance to dislodgment compared with Total Fill BC Sealer and MTA Fillapex (P=0.000). MTA Fillapex resulted in the lowest push-out bond strength (P=0.000). The use of different chelating agents did not influence the push-out bond strength of endodontic sealers. Calcium silicate-based sealers had lower push-out bond strength values compared with a conventional epoxy resin-based sealer (AH Plus).

Effect of endodontic chelating solutions on the bond strength of endodontic sealers

The purpose of this in vitro study was to evaluate the effect of various chelating solutions on the radicular push-out bond strength of calcium silicate-based and resin-based root canal sealers. Root canals of freshly-extracted single-rooted teeth (n = 80) were instrumented by using rotary instruments. The specimens were randomly divided into 4 groups according to the chelating solutions being tested: (1) 17% ethylenediaminetetraacetic acid (EDTA); (2) 9% etidronic acid; (3) 1% peracetic acid (PAA); and (4) distilled water (control). In each group, the roots were further assigned into 2 subgroups according to the sealer used: (1) an epoxy resin-based sealer (AH Plus) and (2) a calcium silicate-based sealer (iRoot SP). Four 1 mm-thick sections were obtained from the coronal aspect of each root (n = 40 slices/group). Push-out bond strength test was performed at a crosshead speed of 1 mm/min., and the bond strength data were analyzed statistically with two-way analysis of variance (ANOVA) with Bonferroni's post hoc test (p < 0.05). Failure modes were assessed quantitatively under a stereomicroscope. Irrespective of the irrigation regimens, iRoot SP exhibited significantly higher push-out bond strength values than AH Plus (p < 0.05). For both the sealers, the use of chelating solutions increased the bond strength, but to levels that were not significantly greater than their respective controls (p > 0.05). iRoot SP showed higher resistance to dislocation than AH Plus. Final irrigation with 17% EDTA, 9% Etidronic acid, and 1% PAA did not improve the bond strength of AH Plus and iRoot SP to radicular dentin.

Adhesive interface and bond strength of endodontic sealers to root canal dentine after immersion in phosphate‐buffered saline

This study evaluated the bond strength (BS) and the adhesive interface of four endodontic sealers to root canal dentine, before, and after immersion in phosphate buffered saline (PBS) to simulate an in vivo environment. Eighty roots were instrumented using ProTaper rotatory files, under irrigation with 17% EDTA and 1% NaOCl. Posteriorly were divided into four groups (n = 20) according to the sealer used: Endofill, AH Plus, Sealapex, and MTA Fillapex. Each group was divided into two subgroups (n = 10) and stored at 37°C immersed in water for 7 days and in PBS for 60 days. From each subgroup, 1 mm thick sections were obtained. One section of each region (coronal, middle, and apical) was submitted to the push-out test and failures were observed. Twelve sections of each subgroup (four from each region) were evaluated under SEM. Three-way ANOVA evaluation for BS showed significant differences between groups and regions (P < 0.0001), but not between subgroups (P > 0.05). AH Plus had significantly higher BS than the others sealers, regardless of the analyzed subgroup (Tukey's test, P < 0.5). The most common failures were adhesive to dentine and cohesive of the sealer. The SEM evaluation (Kruskal-Wallis, Mann-Whitney) showed homogeneous adhesive interface formed and sealer tags in all groups with significant statistical differences with AH Plus, regardless of PBS immersion. AH Plus was superior to the other sealers for both BS and quality of interface formation. Immersion in PBS did not interfere on BS or adhesive interface of the sealers tested.

The bond strength of endodontic sealers to root dentine exposed to different gutta‐percha solvents

To evaluate the effects of various gutta-percha solvents on the push-out bond strength of several root canal sealers on root dentine. The root canals of 210 single-rooted human teeth were prepared with the ProTaper System (Dentsply Maillefer, Ballaigues, Switzerland) up to a master apical file size of F4, and the following variables evaluated for bond strength: solvent type (chloroform, eucalyptol and orange oil), time (2 and 5min), sealer type (AH Plus, MTA Fillapex and Sealapex) and root thirds (coronal, middle and apical). After canal filling, three 1-mm-thick slices were obtained from each root sample, and the bond strength of the test materials was measured using a push-out test set-up at a cross-head speed of 1mmmin(-1) . The data were analysed using four-way factorial anova (P=0.05). Bond strength was significantly affected by solvent type and time (P<0.001). The use of chloroform for 5min in the root canal decreased bond strength of all sealers (P<0.001). Eucalyptol and orange oil did not affect the bond strength of the sealers (P>0.05). In all conditions, the push-out bond strength was highest for AH Plus and lowest for MTA Fillapex (P<0.001). Bond strength values decreased in a corono-apical direction in all groups (P<0.001). Chloroform used for 5min during retreatment decreased the bond strength of AH Plus, Sealapex and MTA Fillapex to root dentine.

The effect of different irrigating solutions on the push out bond strength of endodontic sealer to dentin and assessing the fracture modes: An In-vitro study

Aim: To evaluate the effect of smear clear, 7% maleic acid, 10% citric acid, and 17% EDTA on the push-out bond strength of epoxy resin-based endodontic sealer to dentin. Materials and Methodos: Fifty extracted mandibular premolars were collected. After decoronation using a diamond disc and water spray to obtain approximately 14 mm long root segments, canal patency and working length were established by inserting K file #15 (Mani). The root canals were enlarged using Protaper nickel-titanium rotary instruments to size #F3 at the working length irrigating with 3 mL of 2.6% sodium hypochlorite between each file size. The roots were then randomly divided into four groups (n = 10) according to the final irrigation regimen Group1: Saline (control). Group 2: 17% EDTA, Group 3: 7% maleic acid, Group 4: 10% citric acid, Group 5: Smear clear. Obturation was done using gutta-percha with AH Plus sealer. Each root section was then subjected to a compressive load via a universal testing machine, to measure the push out bond strength followed by assessment of fracture pattern under stereomicroscope. Results: The data was collected and submitted to statistical analysis by one-way analysis of variance (ANOVA) test. Group 3: NaOCl/maleic acid/distilled water showed greater bond strength (2.2+/-0.278 MPa) as compared to other groups. Mixed type of bond failure was predominant. Conclusion: Removal of smear layer with maleic acid as a final rinse enhanced the adhesive ability of AH plus sealer, followed by EDTA and smear clear.

Bond strength of endodontic sealers after intracanal surface pretreatment with CO2 laser

The aim of this study was to evaluate in vitro the bonding of AH Plus and Endofill sealers to intraradicular canal walls after different dentin surface treatments. Material and methods: Sixty canines were sectioned obtaining dentin discs with 4-mm thickness and were embedded in acrylic resin. The canals were prepared with diamond burs. The specimens were divided into two groups(n = 30): GI – AH Plus and GII – Endofill and were subdivided into three groups based on the dentin surface treatment (n = 10): A – distilled and deionized water (control), B – 17% EDTA, C – CO2 laser with 3W in continuous mode for 10s. The specimens were submitted to push out test in a universal testing machine. Results: Tukey test revealed that the IB (AH Plus/17% EDTA) (17.59 ± 6.04) and IC (AH Plus/CO2laser) (21.69 ± 4.93) subgroups had the highest values, which were statistically similar between each other (p &gt; 0.05) and different from the other subgroups (p &lt; 0.05). IIC subgroup (Endofill/CO2 laser)(7.25 ± 1.59) had intermediate values, which were statistically similar to (p &gt; 0.05) IA subgroup (AH Plus/water) (10.99 ± 2.63), IIA subgroup (Endofill/water) (3.16 ± 0.83) and IIB subgroup (Endofill/ 17% EDTA) (5.31 ± 3.61), which had the smallest values (p &lt; 0.05). Conclusion:The treatment of superficial intracanal dentin with CO2 laser and EDTA favored the adhesion of AH Plus and Endofill sealers.

Shearing Bond Strength of Endodontic Sealers to Gutta-percha

Strength of the bond of root canal sealers to gutta-percha seems to be an important property for maintaining the integrity of the apical seal. In the few studies published, different models and assessment methods were used. The purpose of our study was to adapt an effective and easily reproducible model and to test it on nine contemporary commercially available endodontic sealers. Gutta-percha disks with a diameter of 10 mm and thickness of 2 mm were prepared by warming gutta-percha cones and then fixed with plaster in 1-inch phenolic rings. Five-millimeter long sections of polyethylene tubing, filled with freshly mixed sealer, were placed on the gutta-percha and tested for shearing bond strength after setting. A custom-made holder was attached to the rings and placed in an Instron machine, which was activated at a cross-arm speed of 0.5 mm per minute. The bond strength ranged from 0 MPa to 6.4 MPa. The sealers were ranked, and those that did not differ statistically in their bond strength were grouped together. This model provides a simple and reproducible means for measuring the in vitro bond strength of endodontic sealers.

Measurement of Adhesion of Endodontic Sealers to Dentin

The bond strength of root canal sealers to dentin seems to be an important property for maintaining the integrity of the seal of root-canal fillings. In the few studies published, various assessment methods were used so quantitative comparison is not possible. The purpose of this study was to develop an effective and easily reproducible model and to test it with nine contemporary, commercially available endodontic sealers. After slicing off the coronal 2 mm of extracted third molars, the exposed dentin served as test surfaces. The teeth were fixed with plaster in 1-inch phenolic rings. Five-mm long sections of polyethylene tubing, filled with freshly mixed sealer, were placed on the dentin and tested for shearing bond strength after setting. A custom-made holder allowed the rings to be attached to an Instron machine, activated at a cross-arm speed of 0.5 mm/min. The mean bond strength, ranged from 0 to 4.9 MPa. The sealers were ranked and those that did not differ statistically in their bond strength were grouped together. This model provides a simple and reproducible means for measuring the in vitro bond strength of endodontic sealers.