Assessment of different irrigation techniques on the penetration depth of different sealers into dentinal tubules by confocal laser scanning microscope: An in vitro comparative study

Background

The effective disinfection of the entire root canal system aids in the penetration of irrigants into the dentinal tubules further improving sealer penetration and achieving a three-dimensional seal in endodontically treated teeth. Various final irrigation techniques can be employed to achieve this goal. Therefore, this study intended to assess and compare the efficacy of three final irrigation techniques on the depth of penetration of two root canal sealers into dentinal tubules using confocal laser scanning microscope (CLSM).

Methods

Forty-eight single-rooted mandibular premolars were selected and decoronated to a length of 12 mm. All the samples were prepared using ProTaper Gold rotary files and divided into three groups: Group 1 - Conventional syringe irrigation (CSI), Group 2 - passive ultrasonic irrigation (PUI), and Group 3 - Pro-agitator tip system (PATS). Each group was divided into two subgroups: Subgroup A - AH Plus and Subgroup B - GuttaFlow Bioseal (GFB). Then, sealers were mixed with 0.1% rhodamine B dye and the samples were obturated. All the samples were sectioned at 2 mm and 5 mm from the apex and visualized under confocal laser scanning microscope (CLSM) (10×) for maximum mean penetration depth and percentage of sealer penetration. Statistical analysis was done using the independent t-test and one-way analysis of variance test, followed by Tukey's Post hoc analysis.

Results

PUI performed better in the apical third, whereas PUI and PATS showed comparable results in the middle third for both depth and percentage of sealer penetration. Among the two sealers, GFB performed better than AH Plus in both the apical and middle third. These values were statistically significant. (P < 0.05).

Conclusion

Final irrigation activation with PUI or PATS can significantly improve sealer penetration. The average depth of penetration of GFB both at the middle and apical third of the root was significantly superior to AH Plus.

The Effect of Adding Various Antibiotics on the Push-out Bond Strength of a Resin-based Sealer: An In Vitro Study

AIM

This study aimed to compare the bond strength of AH Plus sealer to root canal dentin when used with or without various antibiotics including amoxicillin, clindamycin, and triple antibiotic mixture (TAM).

MATERIALS AND METHODS

A total of 80 single-rooted extracted human teeth were instrumented and obturated with gutta-percha and four different sealer-antibiotic combinations (n = 20). Group I: AH Plus without any antibiotics, Group II: AH Plus with amoxicillin, Group III: AH Plus with clindamycin, and Group IV: AH Plus with TAM. After seven days, the roots were sectioned perpendicular to their long axis and 1 mm thick slices were obtained from the midroots. The specimens were subjected to a push-out bond strength test and failure modes were also evaluated. Data was analyzed using Kruskal-Wallis and Dunn's post hoc tests.

RESULTS

Group IV had significantly higher bond strength compared to other groups (p ≤ 0.05). No significant differences were found between other groups. While the sealer-antibiotic groups predominantly showed cohesive failure modes, the control group displayed both cohesive and mixed failure modes.

CONCLUSION

Within the limitations of this study, the addition of TAM increased the push-out bond strength of AH Plus.

CLINICAL SIGNIFICANCE

Amoxicillin, clindamycin, or TAM can be added to AH Plus for increased antibacterial efficacy without concern about their effects on the bond strength of the sealer. How to cite this article: Adl A, Shojaei NS, Ranjbar N. The Effect of Adding Various Antibiotics on the Push-out Bond Strength of a Resin-based Sealer: An In Vitro Study. J Contemp Dent Pract 2024;25(3):231-235.

Epoxy resin-based root canal sealers: An integrative literature review

The correct obturation of the root canal system achieved by means of a core and a cement is essential for the success of endodontic treatment. There are several root canal cements (RCCs) on the market; however, because of their excellent characteristics, epoxy resin-based sealers (ERBSs) have been widely used. The main aim of this review was to analyze and integrate the available information on different ERBSs. An electronic search was performed in the PubMed and Scopus databases, using "epoxy resin" AND "root canal treatment", and "epoxy resin" AND "endodontics" as search terms. In general, ERBSs have good flow properties, film thickness, solubility, dimensional stability, sealing capacity, and radiopacity. They are also able to adhere to dentin while exhibiting low toxicity and some antibacterial effects. However, their main disadvantage is the lack of bioactivity and biomineralization capability. A large number of ERBSs are available on the market, and AH Plus keeps being the gold standard RCC. Yet, information on many of them is limited or non-existent, which could be due to the fact that some of them are relatively new. The latter emphasizes the need for relevant research on the physicochemical and biological properties of some ERBSs, with the aim of supporting their clinical use with sufficient evidence via prospective and long-term studies.

Evaluation of Sealer Remnants Using a Bioceramic Sealer Single-cone Technique after Post Space Preparation and its Influence on the Adhesion of Fibre Posts in vitro

OBJECTIVE

To compare calcium silicate-based endodontic sealer and epoxy resin-based sealer remnants on root canal walls after post space preparation and their influence on the bond strength of fibre posts fixed with a dual-cured resin cement.

METHODS

Thirty-six extracted single-root mandibular premolars were instrumented and divided randomly into two equal groups with different endodontic sealers. iRoot SP (Innovative BioCeramix, Vancouver, Canada) was employed in the experimental group and AH Plus (Dentsply Sirona, Charlotte, NC, USA) was used in the control group. Sealer remnants were observed under an endodontic microscope after root canal therapy and post space preparation. Fibre posts were fixed with dual-cured resin cement. Specimens were taken at each third of the post space. The push-out bond strength was measured using a universal testing machine and fracture modes were assessed. Statistical analysis was performed using an independent samples t test and one-way analysis of variance.

RESULTS

There was no statistically significant difference in bond strength of fibre posts between the control and experimental group (P > 0.05); however, sealer remnants were observed in 38.9% of the samples treated with iRoot SP and none of the samples treated with AH Plus. The major fracture mode in samples treated with iRoot SP was adhesive failure between the resin cement and the post, and no adhesive failure between the resin cement and dentine occurred at the site of the sealer remnant. The presence of iRoot SP remnants on the root canal walls after post space preparation did not interfere with bonding.

CONCLUSION

iRoot SP is a viable option for root canal obturation before fibre post cementation.

Comparative evaluation of the effect of calcium silicate and epoxy resinbased root canal sealers on postoperative pain in patients with primary endodontic lesion: A randomized clinical study

Introduction

This study's objective was to assess and compare postoperative pain response between bioceramic sealer (Nishika BG) and epoxy resin based (AH Plus) in patients with primary endodontic lesion at time interval of 24 h, 48 h, and 7 days using the Visual Analog Scale (VAS).

Materials and Methods

The study included 40 individuals with necrotic pulp and apical periodontitis. Calcium hydroxide was administered as the intracanal medication during the two-visit endodontic therapy. They were subsequently allocated randomly to either the AH Plus root canal sealer or the Nishika Canal Sealer BG, with a total of 20 participants in each group. Patients were told to use a VAS to rate their postoperative pain severity as none, minimal, moderate, or severe after 24 h, 48 h, and 7 days following obturation using the appropriate sealers.

Results

Nishika Canal Sealer BG (CS-BG) has a lower pain score as compared to the AH Plus group at 24-h time point. VAS ratings for both the groups decreased over time. According to the intergroup analysis, there was a significant difference in postoperative pain at the 24 h (P = 0.022), but not at the 48 h or 7 days (P > 0.05).

Conclusion

Although bioceramic sealer (Nishika Canal Sealer BG) resulted in significantly lower levels of pain as compared to epoxy resin-based sealer (AH Plus) at 24-h interval, there was no significant difference of postoperative pain at 48-h interval and 7-day period.

Biodentine Inhibits the Initial Microbial Adhesion of Oral Microbiota In Vivo

This study aimed to evaluate the in vivo initial microbial adhesion of oral microorganisms on the biomaterial Biodentine compared to MTA and AH Plus. Cylindrical samples of the materials were prepared, and dentin slabs served as a control. An individual intraoral lower jaw splint served as a carrier for the samples and was worn by six volunteers. The specimens were worn for 120 min. Adherent bacteria were quantified by determining the colony-forming units (CFUs), while the visualization and quantification of total adherent microorganisms were facilitated by using DAPI and live/dead staining combined with fluorescence microscopy. Bovine dentin had a significantly higher number of aerobic CFUs compared to Biodentine (p = 0.017) and MTA (p = 0.013). The lowest amounts of DAPI-stained adherent microorganisms were quantified for Biodentine (15% ± 9%) and the control (18% ± 9%), while MTA showed the highest counts of initially adherent microorganisms (38% ± 10%). Significant differences were found for MTA and Biodentine (p = 0.004) as well as for MTA and the control (p = 0.021) and for AH Plus and the control (p = 0.025). Biodentine inhibited microbial adherence, thereby yielding an antimicrobial effectivity similar to that of MTA.

Influence of 2% chlorhexidine on the dislodgement resistance of AH plus, bioroot RCS, and GuttaFlow 2 sealer to dentin and sealer-dentin interface

Aim

To find out the effects of 2% chlorhexidine (CHX) gel intracanal medicament on the dislodgement resistance of AH Plus, BioRoot RCS, and GuttaFlow 2 Sealer to dentin and on sealer-dentin interface.

Materials and Methods

Sixty single-rooted maxillary canine were taken and divided into two groups based on the treatment: Group 1 - control group (no medicament) (n = 30) and Group 2 - (GLUCO-CHeX 2% Gel) (n = 30). Further, the groups were divided according to the sealer used, namely (A) AH Plus sealer, (B) BioRoot RCS Sealer, and (c) Gutta Flow 2 sealer. Teeth were prepared using rotary instrumentation of file size 35 with a taper of 0.06 and obturation was done. 1 mm thick sections were obtained from the roots. All the sections were checked for push out bond strength using Universal testing machine and mode of failure using stereomicroscope. Some samples were evaluated for sealer-dentin interface using field emission scanning electron microscope.

Results

AH Plus showed higher bond strength compared to BioRoot RCS and GuttaFlow 2. There was no significant difference in the push out bond strength with or without the prior use of 2% CHX medicament (P > 0.05) and also CHX did not affect the mode of failure. However, sealer-dentin interface gap was increased with application of medicament.

Conclusion

Dislodgement resistance of AH Plus sealer is significantly higher than BioRoot RCS and GuttaFlow 2 sealer. The application of 2% CHX intracanal medicament before root canal obturation did not significantly affect the dislodgement resistance of the three tested sealers. 2% CHX medicament did not affect the failure mode of the sealers. Sealer-dentin interface is affected by the use of 2% CHX gel medicament.

The Effect of Primary Root Canal Treatment on Dentinal Tubule Penetration of Calcium Silicate-based Sealers during Endodontic Retreatment

INTRODUCTION

The aim of this study was to evaluate the effect of previous root canal treatment on dentinal tubule penetration of calcium silicate-based sealers during endodontic retreatment and to compare 2 different (commonly used and modified) tubule penetration depth measurement techniques.

METHODS

The crowns of mandibular premolar teeth were removed, and root canals were prepared (ProTaper Universal; Dentsply Sirona, York, PA) and obturated using AH Plus (AH; Dentsply DeTrey, Konstanz, Germany), MTA Fillapex (MTAF; Angelus, Londrina, Brazil), and WellRoot ST (WRST; Vericom, Gyeonggi-do, South Korea); 0.1% red Rhod-2 dye (Chemodex, St Gallen, Switzerland) was added to the sealers. After storage for 3 weeks (37°C, 100% humid), the following sealer combination subgroups were created (the sealer used during the primary root canal treatment/the sealer used during the retreatment, n = 8): AH/AH, AH/MTAF, and AH/WRST; MTAF/AH, MTAF/MTAF, and MTAF/WRST; and WRST/AH, WRST/MTAF, and WRST/WRST. Green Fluo-3 dye (0.1%) was added to the sealers during retreatment. Sealer penetration depths were measured at 8 points and averaged, and the ratio of the retreatment sealer to the initial sealer was recorded as the mean tubule penetration depth ratio in the first technique, whereas the percentage of the circumferential penetration area ratios of the retreatment and initial sealers was calculated in the second technique. Statistical analyses were performed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests.

RESULTS

The mean penetration depth of AH and MTFA was found to be higher at the coronal third region in the control groups (P < .05). Both methods showed a significant difference among the groups at the coronal and median regions (P < .05). The AH/WRST, MTAH/AH, MTAF/MTAF, MTAF/WRSTS, and WRST/WRST groups showed deeper tubule penetration (first technique, P = .01). Both techniques showed that the penetration depth of the sealers was the same at the apical region (P > .05), whereas a difference was found among the techniques at the coronal and median regions. The sealers used in the previous root canal treatment limited the penetration depth of the sealers used during the retreatment process (P < .05). When MTAF was used as the initial sealer, the penetration depth of the second sealer did not change, whereas if WRST was the initial sealer, the penetration depth of the sealers at the median and apical regions is negatively affected during the retreatment process (P < .05).

CONCLUSIONS

Previous root canal treatment affects the penetration depth of calcium silicate-based sealers. The use of AH Plus and MTA Fillapex during the retreatment process showed an advantage. Both measurement techniques showed similar performances at the apical region, whereas the results varied at the coronal and midcoronal regions; therefore, a more stable sealer penetration measurement technique is still necessary.

Assessment of Bioceramic Sealer Retreatability and Its Influence on Force and Torque Generation

This study assesses the retreatability of TotalFill bioceramic (TFBC) and AH Plus (AHP) sealers and their impact on retreatment force and torque. Twenty-six premolar teeth with single oval canals were instrumented, obturated using the matched gutta-percha cone technique with one of the tested sealers, and then temporized. After a 6-month incubation at 37 °C and 100% humidity, the canals were retreated with the XP Shaper system. During retreatment, the generated force and torque were measured. Micro-CT scanning was run before and after the retreatment procedure to analyze the remaining obturating materials in the canals. The apically directed maximum force in AHP was higher than that in TFBC. The coronally directed maximum force and the maximum torque were comparable between the groups. A higher amount of remaining obturating materials was found in the AHP compared to that in the TFBC. Based on these findings, endodontic sealer had an influence on retreatability, and the TFBC showed less remaining obturating materials and lower retreatment forces in the apical direction compared to the AHP in extracted teeth with oval canals.

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.

Bone repair in defects filled with AH Plus sealer and different concentrations of MTA: a study in rat tibiae

Objectives

This study aimed to evaluate the effects on bone repair of different concentrations of mineral trioxide aggregate (MTA) added to AH Plus.

Materials and Methods

Bone tissue reactions were evaluated in 30 rats (Rattus norvegicus) after 7 and 30 days. In the AH + MTA10, AH + MTA20, and AH + MTA30 groups, defects in the tibiae were filled with AH Plus with MTA in proportions of 10%, 20% and 30%, respectively; in the MTA-FILL group, MTA Fillapex was used; and in the control group, no sealer was used. The samples were histologically analyzed to assess bone union and maturation. The Kruskal-Wallis and Mann-Whitney tests were performed for multiple pairwise comparisons (p ≤ 0.05).

Results

At the 7-day time point, AH + MTA10 was superior to MTA-FILL with respect to bone union, and AH + MTA20 was superior to MTA-FILL with respect to bone maturity (p < 0.05). At the 30-day time point, both the AH + MTA10 and AH + MTA20 experimental sealers were superior not only to MTA-FILL, but also to AH + MTA30 with respect to both parameters (p < 0.05). The results of the AH + MTA10 and AH + MTA20 groups were superior to those of the control group for both parameters and experimental time points (p < 0.05).

Conclusions

The results suggest the potential benefit of using a combination of these materials in situations requiring bone repair.

Effect of calcium silicate-based endodontic sealer on the retention of fiber posts cemented at different time intervals

Objective

To evaluate the effect of BC HiFlow, a new calcium silicate-based endodontic sealer, compared with a resin epoxy-based sealer after 2 different times of cementation on the pull-out bond strength of glass-fiber–reinforced composite posts cemented with a self-adhesive resin cement (RelyX Unicem).

Methodology

Sixty human maxillary central incisors were decoronated, prepared and obturated with gutta-percha and sealer. Roots were distributed into 5 groups according to the sealer and time of post cementation: (1) AH Plus sealer with immediate post fixation, (2) BC HiFlow with immediate post fixation, (3) AH Plus and post fixation after 7 days, (4) BC HiFlow and post fixation after 7 days, and (5) fiber post fixation in canals obturated with gutta-percha only (no sealer). After 1 week of post cementation, the pull-out test was performed and the failure mode was examined under a digital microscope. Data were analyzed using ANOVA followed by Tukey's post hoc and t tests (p < .05).

Results

With immediate post cementation, AH Plus group showed significantly higher pull-out retentive strength than the BC HiFlow and control groups (p = .009 and p < .001, respectively). There was no significant difference between the groups when the posts were cemented 7 days after obturation (p = .726). The time of post cementation had a significant influence on the canals obturated with AH Plus (p = .003). The time did not significantly affect the canals obturated with BC HiFlow (p = .289). The prominent type of failure was mixed mode in all groups.

Conclusion

BC HiFlow sealer did not affect the pull-out bond strength of glass-fiber–reinforced composite posts cemented with a self-adhesive resin cement immediately after or 7 days after obturation. For immediate post cementation, AH Plus increased the pull-out bond in comparison to BC HiFlow.

Minimal Dentinal Tubule Penetration of Endodontic Sealers in Warm Vertical Compaction by Direct Detection via SEM Analysis

Sealer staining using rhodamine B dye to investigate the penetration depth of endodontic sealers was proven unsuitable for this purpose. This study aimed to investigate the sealer penetration depth into dentinal tubules by scanning electron microscopy (SEM). Root canals of 52 human upper central incisors were instrumented using the ProTaper Gold NiTi system (Dentsply Sirona, York, PA, USA) up to size F3. After irrigation with sodium hypochlorite and citric acid combined with ultrasonic activation, the root canals were either filled using the epoxy resin sealer AH Plus (Dentsply Sirona) or the calcium silicate-based sealer Total Fill BC Sealer HiFlow (TFHF, FKG Dentaire, La Chaux-de-Fonds, Switzerland) by warm vertical compaction. Root slices of 1 mm thickness were obtained at 2 to 3, 5 to 6 and 8 to 9 mm from the apex. The root slices were investigated for sealer penetration into the dentinal tubules using SEM according to four root quadrants (buccal, mesial, oral, distal). Statistical analysis was performed by the Kruskal-Wallis test (p = 0.05) as data were not normally distributed according to the Shapiro-Wilk test. AH Plus penetrated significantly deeper into the dentinal tubules compared to TFHF at each root level (p < 0.05). Dentinal sealer penetration was deeper in the bucco-oral direction compared to the mesio-distal direction. AH Plus penetrated deeper into dentinal tubules than TFHF. Warm vertical compaction exerting high pressure on the root canal filling material is not able to press sealers deep into dentinal tubules as penetration depth values did not exceed a mean of 110 µm in SEM.

A Confocal Microscopic Study on Percentage Penetration of Different Sealers into Dentin

Context:

Three-dimensional seal of the root canal space has always been challenging. The incorporation of gutta-percha and sealer prevents microleakage by bacteria, ensuring a shielded root canal space. However, the penetration of sealer to various depths within the root canal has always been looked with curiosity.

Aims:

Thus, the present in vitro study was undertaken to evaluate the percentage and average depth of penetration of Endoflas F. S., AH Plus, and Epiphany sealers into dentinal tubules among the coronal, middle, and apical thirds of the roots following obturation with a lateral compaction technique using Confocal Laser Scanning Microscopy.

Settings and Design:

The study is an in vitro randomized control trial.

Subjects and Methods:

Thirty sound central incisors were decoronated at the level of the cementoenamel junction. Working length determination was done followed by a meticulous cleaning, shaping, and under copious irrigation. The teeth were then randomly divided into three groups: Endoflas FS sealer, AH Plus sealer, and Epiphany sealer. On fluorescence treatment, the teeth were sectioned at the midpoint of coronal, middle, and apical third of each root and viewed under confocal laser scanning microscope.

Statistical Analysis Used:

The results were analyzed using one-way ANOVA, and the significant difference between groups was analyzed with post hoc Tukey test.

Results:

Epiphany sealer provided with better percentage and depth penetration in comparison to Endoflas FS and AH Plus sealers. Furthermore, the coronal third of the root had better percentage and sealer penetration than the middle and apical thirds.

Conclusions:

Sealers tend to provide a firm bond between the tooth and the gutta-percha. They bind, lubricate, and seal the gutta-percha cones to fill the accessory canals. Within the limitations of this study, the superior flow and enhanced setting time Epihany sealers provide better percentage and depth of penetration than AH Plus and Endoflas FS.

Comparison of Sealing Ability of Bioceramic Sealer, AH Plus, and GuttaFlow in Conservatively Prepared Curved Root Canals Obturated with Single-Cone Technique: An In vitro Study

Background:

Inadequate obturation techniques of the root canal system have been found to be the most frequent reason of failure post root canal treatment. An ideal endodontic sealer should fulfill all ideal requisites. The present study aimed to compare apical sealing ability between bioceramic (BC) sealer, GuttaFlow, and AH Plus.

Methodology:

One hundred and twenty-five curved roots of maxillary and mandibular third molar teeth with fully formed apex were collected for this study. The root canals were cleaned and shaped using a standard single-cone preparation to file at the established working length and divided into five groups of 25 each. Dye leakage was carried out. Group A: with GP, using EndoSequence BC sealer with conventional with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group B: with ceramic coated with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group C: with GP, using AH Plus sealer (Dentsply, De-Trey Konstanz, Germany) with 4% gutta-percha; Group D: with GuttaFlow bioseal (Roeko-Coltène/Whaledent, Langenau, Germany) with 4% Gutta-percha; and Group E is a negative control group. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.

Results:

The group AH Plus showed more leakage values than the GuttaFlow group and of two groups of BC sealer and negative control. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.

Conclusion:

None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal.

A micro-computed tomographic evaluation of retreatability of BioRoot RCS in comparison with AH Plus

This study compared the retreatability of filling material from canals filled with BioRoot RCS (Septodont, Saint-Maur-des-Fosses, France) and AH Plus (Dentsply DeTrey, Konstanz, Germany) combined with gutta-percha using micro-computed tomography for evaluation. Thirty-four mandibular premolars were divided into two groups according to the sealer used. Thirty days after obturation, canals were retreated with a ProTaper Universal retreatment system (Dentsply Maillefer, Ballaigues, Switzerland) followed by passive ultrasonic irrigation (PUI). The time taken for retreatment was recorded. The roots were scanned after obturation, after retreatment and after PUI. Data were analysed using the Mann-Whitney and Wilcoxon tests. Canals filled with BioRoot RCS exhibited significantly less remaining filling material than canals filled with AH Plus (P < 0.05). The addition of PUI resulted in a significant decrease in the residual material in both groups (P < 0.05). A significantly shorter retreatment time was reported for the AH Plus group than the BioRoot RCS group (P < 0.05).

Debunking the Concept of Dentinal Tubule Penetration of Endodontic Sealers: Sealer Staining with Rhodamine B Fluorescent Dye Is an Inadequate Method

The aim of this study was to investigate the suitability of rhodamine B dye staining of an epoxy resin sealer (AH Plus) and calcium-silicate-based sealers (Total Fill BC Sealer, BioRoot RCS) to represent the penetration depth of the sealers into dentinal tubules after root canal obturation. In a three-step process, (1) leaching of rhodamine B from sealers into a buffer solution, (2) passive penetration of leached rhodamine B into dentinal tubules, and (3) conformity of rhodamine B penetration assessed by confocal laser scanning microscopy (CLSM), and sealer penetration assessed by scanning electron microscopy (SEM), in root-canal-filled teeth, were evaluated. Rhodamine B dye massively leached out of Total Fill BC Sealer and BioRoot RCS into the phosphate-buffered saline (PBS). A pinkish coloration of AH Plus was found after contact with PBS. Leached rhodamine B dye passively penetrated dentinal tubules from all three sealers when placed on root dentin. No correlation was observed between sealer penetration in SEM and rhodamine B penetration in CLSM. Staining of sealers using rhodamine B is an inadequate method with which to evaluate sealer penetration depth into dentinal tubules, as it overestimates the penetration of sealers into root dentin tubules.

Management of apical periodontitis using WaveOne gold reciprocating files, single-cone endodontic approach: A case series author

Introduction

The endodontic treatment of apical periodontitis (AP) without surgical intervention presents a unique clinical challenge. This case series aimed to test the changes in size of periapical lesion scale and healing in post-treatment of AP by cone beam computed tomography (CBCT) using Waveobe Gold reciprocating file with single cone treatment approach.

Presentation of cases

A total of 20 patients with 20 teeth (9 M, six premolars, one canine, and four incisors) with AP underwent CBCT scanning before and after non-surgical root canal treatment (NSRCT) or non-surgical retreatment (NSReTx). Standardized root canal chemo-debridement and instrumentation with WaveOne Gold (WOG) reciprocating files was used. The canals were obturated using epoxy-based sealer (AH Plus) with a single WaveOne Gold conform fit gutta-percha cone technique. After one year, assessment with CBCT images showed that the success and healing rate using (AH Plus) with single cone technique was very high.

Discussion

Apical periodontitis is an inflammatory disease at the root end of teeth. Following NSRCT or NSReTx, evaluation of lesion size by radiograph has been essential to the evaluation of lesions post-operatively. In addition to the absence of symptoms, complete restitution of the lamina dura and periodontal ligament (PDL) space on post-operative radiograph has been considered the optimal outcome success.

Conclusions

Within the limitations of this study, NSRCT or NSReTx using reciprocating WaveOne Gold and single cone with AH plus sealer resulted in healing of AP as assessed by CBCT.

•

This case series report consider the first clinical trial assessing the outcome of Non-surgical root canal treatment on healing of apical periodontitis by CBCT in different tooth types with primary apical periodontitis without endodontic treatment and post apical periodontitis with inadequate apical filling.

•

Within the limitations of this study, NSRCT or NSReTx using reciprocating WaveOne Gold files and single cone with AH plus sealer resulted in healing of AP as assessed by CBCT.

The presence of smear layer affects the antimicrobial action of root canal sealers

AIM

To assess the chemical and microstructural characteristics of dentine after the use of two irrigation protocols and correlate this with the antimicrobial properties of hydraulic calcium silicate cement (HCSC) sealers and changes to the dentine structure/chemistry after sealer placement.

METHODOLOGY

Two irrigation protocols - Protocol A using 2% NaOCl used 5 mL/5 min and Protocol B with 2% NaOCl (5 mL/5 min) followed by 17% EDTA (5 mL/3 min) - were used to prepare dentine. The chemical and microstructural changes following irrigation were assessed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy (n = 5) on dentine obtained from the mid-root and coronal parts of extracted human teeth. Four sealers (AH Plus, BioRoot, MTA Fillapex, TotalFill) were characterized by SEM/EDS (n = 3). The ability of the sealers to eradicate intratubular Enterococcus faecalis biofilms was assessed by live/dead dye and confocal laser scanning microscopy to measure the percentage of living cells. The effect of combined irrigation and root filling on dentine was assessed by SEM and EDS analysis (n = 5). Statistical analysis was undertaken using one-way anova and a number of post hoc tests to detect intergroup differences. The F-test was used for comparison of variances in the microbiology testing.

RESULTS

The use of NaOCl alone left the smear layer intact, with traces of chlorine remaining on dentine. The use of BioRoot sealer restored the calcium levels of dentine which had been depleted by the irrigation with EDTA. BioRoot exhibited antimicrobial properties against intratubular bacteria even in the presence of smear layer (Protocol A). Smear layer removal improved the bactericidal effect of all sealers and Ca²⁺ leaching. The use of a chelating agent was important for the intratubular sealer penetration for AH Plus but not the other sealers.

CONCLUSION

The removal of smear layer was necessary for penetration of AH Plus into the dentinal tubules. BioRoot was a more effective sealer in reducing the bacterial load in the dentinal tubules than the other materials tested and the presence of smear layer did not affect its activity.

The effect of two endodontic sealers and interval before post-preparation and cementation on the bond strength of fiber posts

OBJECTIVES

To evaluate the effect of different endodontic sealers (epoxy resin-based and bioceramic-based) and the time of post-cementation on the bond strength of a fiber post cemented with resin cement.

METHODS

Forty human premolars were instrumented and divided into 4 groups. According to the type of sealer and the time of post-cementation: AH-IM (AH Plus, post-cemented immediately after root canal treatment), SP-IM (iRoot SP, post-cemented immediately after root canal treatment), AH-OW (AH Plus, post-cementation after one week), and SP-OW (iRoot SP, post-cementation after one week). In each group, the samples were submitted to push-out test, and failure mode was assessed. Levene's test, one-way ANOVA, and Kruskal-Wallis analysis were applied for statistical analysis (α = 5%).

RESULTS

The highest mean push-out bond strength was obtained from the SP-IM group in the apical part (10.45 ± 5.15MPa), while the lowest was observed in samples from the AH-OW group in the middle part (2.63 ± 1.54 MPa). One-way ANOVA showed that within the same root region, the time of post-cementation had a negative influence on the bonding strength in the SP groups in the middle and apical portion (P<0.05), however, when comparing the effect of type of sealers on bonding strength between the OW groups or IM groups within the same root region, no significant difference was observed regardless of the post cementation time (P>0.05).

CONCLUSIONS

The bond strength of the fiber post was higher when the post was cemented immediately after root canal treatment when the bioceramic sealer was applied.

CLINICAL RELEVANCE

The correct choice of an endodontic sealer and the proper time of post-cementation may help to obtain the best quality of post-and-core restoration.

Data on the push-out bond strength of three different root canal treatment sealers

It is of interest to document data on the push - out bond strength of three different root canal treatment sealers such as MTA Fillapex (MTA based), AH plus (Epoxy Resin based) and Apexit plus (Calcium hydroxide based). Forty-five freshly extracted human maxillary central incisors with closed apices were selected randomly. All the teeth were sectioned at cement-enamel junction using a diamond disc before starting the root canal preparation to obtain root length of 12 mm. All teeth were instrumented using ProTaper rotary instruments. 5.25% sodium hypochlorite was used for irrigation between instrumentation followed by 17% EDTA, and final rinse by saline. Obturation procedures were done using the gutta-percha single cone technique. 45 roots were randomly assigned to 3 groups of 15 for obturation with gutta-percha cones and 1 of the 3 sealers (n=15). Group 1 = MTA Fillapex sealer + gutta-percha: Group 2 = AH plus sealer + gutta-percha:Group 3 = Apexit plus sealer + gutta-percha. The roots were sectioned horizontally to its canal into 3 sections: Coronal, Mid-root and Apical-thirds using a precision cutting machine, with a thickness of 3 mm. The specimens were subjected to push-out test using a universal testing machine that carried a plunger. The loading speed was 1mm/min until the dislodgment of the material occurred. The independent t- test was used to compare the mean scores among the study groups. The level of significance was set at 5% for all tests. After the push-out bond strength test, each sample was evaluated under stereomicroscope (40x) to determine the mode of failure and recorded as one of the following categories: adhesive, cohesive or mixed. The observations thus obtained were subjected to statistical analysis using Student - t test. AH Plus showed significantly higher values than MTA Fillapex and Apexit plus (p < 0.05). Amongst the push-out bond strength AH Plus sealer showed significant difference from MTA Fillapex and Apexit plus groups. There was no significant difference between MTA Fillapex and Apexit plus however (p>0.05). Microscopic analysis displayed that the majority of the modes were cohesive failures for AH Plus, adhesive failures for MTA Fillapex and mixed failures for Apexit Plus. . Thus, AH Plus had the highest bond strength and MTA Fillapex had the lowest bond strength to root dentin. Mean push-out bond strength values were ranked as follows; AH Plus >Apexit Plus > MTA Fillapex. Microscopic analysis displayed that the majority of the modes were cohesive failures of AH Plus, adhesive failures for MTA Fillapex and mixed failures for Apexit Plus.

Evaluation of push-out bond strength of BioRoot RCS and AH Plus after using different irrigants: An in vitro study

Aim:

The aim of this study was to compare push-out bond strength of root canal spaces filled with AH-Plus and BioRoot RCS after using different irrigants.

Materials and Methods:

Eighty single-rooted teeth were decoronated and endodontically treated by crown-down technique using ProTaper Universal rotary files progressively till F4 (40/0.06). Samples were divided into two groups according to the sealer (n = 40): Group A = BioRoot RCS, Group B = AH Plus, further subdivided into four subgroups according to irrigation protocol (n = 10): Group 1A, 1B – 0.9% saline, Group 2A, 2B – 5.25% NaOCl + 17% EDTA, Group 3A, 3B– 17% EDTA +2% chlorhexidine, and Group 4A, 4B – 17% EDTA + 3% green tea extract. Samples were obturated with sealers and prepared for push-out test with root slices of 2 mm thickness using universal testing machine. Data were statistically analyzed using two-way ANOVA, Bonferroni's post hoc analysis, and independent Student's t-test.

Results:

BioRoot RCS exhibited significantly higher push-out bond strength (n < 0.001). The interaction between irrigants and sealer showed higher bond strength for BioRoot RCS when 17% EDTA+ green tea was used.

Conclusion:

Within the limitation of the study, it was concluded that bond strength of a sealer was influenced by the irrigants used.

Comparative evaluation of push-out bond strength of gutta-percha using different sealers with lateral condensation and thermoplasticized obturation technique: An in vitro study

Aim:

The study aimed to evaluate and compare the push-out bond strength of gutta-percha using AH plus, Endosequence BC, and Roeko seal sealer with lateral condensation and thermoplasticized obturation technique.

Materials and Methods:

Sixty single-rooted premolars were instrumented and samples were randomly assigned into three groups based on the sealer used (Group A-AH Plus, Group B-Endosequence BC, Group C-Roeko Seal) which were further divided into two subgroups-A1, B1, and C1 were obturated by the lateral condensation technique and A2, B2, and C2 using the thermoplasticized technique. Each sample was sectioned horizontally using a diamond disc, representing apical, middle, and coronal thirds, respectively. Root segments were then mounted on an acrylic block, and push-out bond strength of each sample was tested using the universal testing machine.

Statistical Analysis:

One-way ANOVA, Tukey's test, and unpaired t-test.

Results:

For mandibular premolar teeth with a single canal using lateral condensation technique, the highest push-out bond strength was found in the A1 group (7.30 ± 0.61 MPa) at the apical level. While using the thermoplasticized technique, the highest push-out bond strength was found in the B2 group (3.71 ± 0.81 MPa) at the apical level. Overall results showed that the lateral condensation technique showed significantly higher push-out bond strength than thermoplasticized technique (P < 0.028).

Conclusions:

The push-out bond strength of AH Plus sealer was higher than the Endosequence BC sealer and Roeko seal sealer. Lateral condensation technique has shown higher push-out bond strength than the thermoplasticized technique.

Effect of different obturating techniques and sealers on the removal of filling materials during endodontic retreatment

Background:

Adequate removal of previous root filling materials is an important objective during endodontic retreatment.

Aim:

This study was aimed to evaluate the influence of obturation quality and sealer type on the removal of root filling materials during endodontic retreatment using micro-computed tomography (μ-CT).

Materials and Methods:

Ninety extracted mandibular premolars were randomly assigned to two groups (n = 45) based on the type of sealer (AH Plus and BioRoot RCS) and three sub-groups based on the obturating technique used, i.e., cold lateral condensation, warm vertical compaction, and thermoplasticized injectable techniques. Specimens were scanned using μ-CT before and after retreatment to assess the amount of filling material, and time taken for removal was recorded.

Statistical Analysis:

Data were analyzed using two-way analysis of variance and Tukey's multiple post hoc test at 5% significance level.

Results:

Filling debris percentage and retreatment time were not significantly affected by the type of sealer (P ≥ 0.05). The percentage of remaining filling material was higher in teeth obturated with thermoplasticized technique (P < 0.05). Significantly more filling material debris was observed in apical third (P < 0.05).

Conclusions:

The type of obturating technique used for initial root canal treatment has influenced the amount of remaining filling material and retreatment time. Retreatability of the BioRoot RCS sealer was similar to the AH Plus sealer.

Fracture Resistance of Roots Filled With Bio-Ceramic and Epoxy Resin-Based Sealers: In Vitro Study

Objective

This study aimed to assess the resistance of roots to fracture after being root canal filled with two types of endodontic sealers; bio-ceramic based sealer (TotalFill) and epoxy-resin based sealer (AH Plus).

Methods

Fifty-nine single canal mandibular premolars were instrumented. Group I (n=14, negative control): root canals were left without instrumentation and unfilled, group II (n=15, positive control): root canals were instrumented only and left unfilled, group III and IV (n=15 each): root canals were instrumented and filled with either gutta-percha/TotalFill or gutta-percha/AH Plus, respectively. The resistance of the roots to fracture was measured with a universal testing machine "Instron Corp" through recording the maximum force in Newton (N) needed to fracture each root. To analyze the data Kruskal-Wallis test was utilized, followed by Dunn's Bonferroni post hoc test for multiple comparisons. The level of significance was set at 0.05 (P≤0.05).

Results

TotalFill group showed slightly better fracture resistance (734.62 N) than AH Plus group (728.29 N). However, no statistical significant difference was found between the two groups (P>0.05). The greatest mean fracture force was shown in the negative control group (913.915 N) with statistical significant difference between the other three groups (P<0.05).

Conclusion

Gutta-percha/TotalFill and gutta-percha/AH Plus did not reinforce the root canal treated teeth.

Fracture Resistance of Endodontically Treated Teeth Obturated with Different Root Canal Sealers (A Comparative Study)

AIM

The aim of this study is to compare the effect of different root canal sealers on the fracture resistance of endodontically treated teeth using AH Plus, GuttaFlow 2, MTA-Fillapex, and TotalFill® BC™ sealers.

MATERIALS AND METHODS

Sixty single-rooted mandibular premolar teeth were used in the study. After the decoronation of the crowns of the teeth, we got a 13 mm root length. All samples instrumented using ProTaper Next system reaching file size ×4 as the final master apical file. Gutta-percha (GP) with single cone as obturation technique was carried out to all experimental teeth. Then, the teeth were divided into five groups (n = 12) based on the type of sealer to be used. Group I: AH Plus sealer + GP, Group II: GuttaFlow 2 sealer + GP, Group III: MTA-Fillapex sealer + GP, Group IV: TotalFill BC sealer + GP, and Group V: control (instrumented but unobturated teeth). Embedding all teeth in acrylic resin blocks was carried out and fracture force was measured using a universal testing machine (Instron Corp., Canton, MA, USA) by using metal-like spreader tip on 0.5 mm/m speed. Then, the data were statistically evaluated using one-way analysis of variance (ANOVA) and post hoc test (Tukey's test).

RESULTS

Group IV showed higher resistance to fracture than other groups significantly. There was a nonsignificant difference in fracture force between Group I, Group II, and Group III. Group V showed the least fracture resistance than other groups.

CONCLUSION

Based on this in vitro study, TotalFill bioceramic-based sealer was more effective when compared with other sealers and the unobturated group showed the lowest mean fracture resistance.

CLINICAL SIGNIFICANCE

The use of bioceramic sealer with BC cones enhanced the fracture resistance of endodontically treated teeth.

Comparative Evaluation of Physicochemical Properties and Apical Sealing Ability of a Resin Sealer Modified with Pachymic Acid

Objective:

The addition of pachymic acid (PA) to AH Plus (an epoxy resin sealer) offsets the cytotoxicity of the latter. Prior to the clinical implementation of this formulation, a thorough knowledge of its physicochemical properties and sealing ability becomes mandatory. Hence, this in vitro study aimed to characterize and evaluate the physicochemical properties and apical sealing ability of AH Plus (AHP) with and without the addition of PA.

Methods:

Flow, setting time, film thickness, solubility and radiopacity of AHP (group 1) and AHP modified with PA (AHP/PA, group 2) were evaluated in accordance with the guidelines put forth by ISO 6876:2012. The percentage was determined under each parameter. Apical sealing ability was assessed using fluid filtration device. An independent samples t-test was used for inter- and intra-group comparisons of mean fluid flow (MFF).

Results:

Incorporating PA to AHP decreased its flow, setting time and film thickness by 24.34%, 2.14% and 31.71% respectively. The solubility of group 2 increased on day 1 by 85.71% and decreased on days 3, 7 and 14 by 46.67%, 34.79% and 13.8% respectively. The radiopacity of AHP was not altered by the addition of PA. MFF rates of group 2 was significantly higher than group 1 on day 1, but not significantly different on day 7.

Conclusion:

AHP/PA exhibited physicochemical properties that were within the requirements of ISO and with time, and showed fluid flow similar to AHP.

Evaluation of Dentin Adaptability of Fluoride Varnish as a Root Canal Sealer Using Scanning Electron Microscopy

Objectives:

This study aimed to assess the dentin adaptability of a certain type of fluoride varnish, as a novel root canal sealer, in comparison with AH-Plus sealer.

Materials and Methods:

Twenty-four extracted single-rooted, single-canal human permanent teeth with straight and fully formed roots and no internal calcification, resorption or cracks, were selected and decoronated such that the remaining root length was 14 mm in all teeth. Root canals were prepared using the Mtwo rotary file system according to the manufacturer’s instructions and filled with gutta-percha and either AH-Plus (n=12) or fluoride varnish (n=12) via the lateral compaction technique. Each root was then sectioned at 4 and 8 mm distances from the apex for evaluation under a scanning electron microscope (SEM). The gap size between the sealer and dentin was measured. Statistical analysis was performed using the Kolmogorov-Smirnov test and t-test with the significance level set at 0.05.

Results:

The mean gap size was 14.407±1.402 μm and 8.342±0.694 μm in the roots obturated with AH-Plus and fluoride varnish sealers, respectively. The t-test revealed a statistically significant difference (P<0.001) in this regard between the two groups.

Conclusion:

Fluoride varnish, as a root canal sealer, has a superior adaptation to dentinal canal walls compared to the AH-Plus sealer.

Evaluation of Sealing Ability of Three Root Canal Sealers: An In Vitro Study

AIM

To evaluate the sealing ability of three different types of sealers using confocal laser microscopy.

MATERIALS AND METHODS

Sixty extracted single-root premolars were selected and divided into three groups (20 teeth in each group) according to the type of sealer used, namely, mineral trioxide aggregate (MTA) Fillapex, AH Plus, and Bio C Sealer. Root canal preparation and obturation were done in all the samples. Roots was dissected transversely in apical plane. Percentage of gap from region to canal circumference was calculated using a confocal laser microscope. Samples were subjected to statistical analysis.

RESULTS

High dye penetration was seen with AH Plus compared to MTA Fillapex and least with Bio C Sealer. The AH Plus is the best sealer with respect to seal ability of all the three.

CONCLUSION

This study helps to appraise the sealing ability of the different types of sealers using confocal laser microscopy which is useful for the success of root canal treatment.

CLINICAL SIGNIFICANCE

As sealer has to seal voids, foramina, and canals, it should have good penetration for the success of root canal treatment.

Physico-chemical investigation of endodontic sealers exposed to simulated intracanal heat application: epoxy resins and zinc oxide-eugenols

AIM

To gain information in a laboratory setting about the effect of thermal treatment of epoxy resin-based and zinc oxide-eugenol-based sealers.

METHODOLOGY

AH Plus and Pulp Canal Sealer (PCS) were exposed to thermal treatment at 37, 47, 57, 67, 77, 87 and 97 °C for 30 s. According to clinically relevant considerations, intracanal sealer temperature is likely not to exceed 60 °C during warm vertical root canal filling. Heat application is recommended for less than 30 s during continuous wave technique, but might exceed this threshold in complex cases. Furthermore, heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate implementation of warm vertical filling techniques. Specimens were heated inside 2-mL plastic tubes in a thermo-controlled water bath until the temperatures were reached and kept at this temperature for the determined period of time. Afterwards, specimens were cooled to body temperature and physical properties (setting time, flow, film thickness according to ISO 6876) were assessed. Chemical properties (Fourier transformed infrared spectroscopy) were assessed after complete setting of the specimens in an incubator at 37 °C and 100% humidity. Statistical analysis of physical properties was performed using Kruskal-Wallis test (P = 0.05).

RESULTS

The setting time of AH Plus and PCS decreased when temperature and duration of heat application increased. Whilst the setting time of AH Plus decreased from 622 min at 20 °C (for 30 s) to 381 min at 97 °C (for 180 s; P < 0.05), heat treatment of PCS at 97 °C for 180 s led to an immediate setting of the material. From 20 °C (for 30 s) to 97 °C (for 30 s), the setting time of PCS decreased from 80.1 to 41.0 h (P < 0.05). Film thickness and flow were not relevantly influenced by thermal treatment except for PCS at 97 °C for 180 s. FT-IR spectroscopy did not reveal any chemical changes of either sealer after thermal treatment.

CONCLUSIONS

Thermal treatment simulating clinically relevant temperature levels and heating times did not lead to any substantial physical or chemical changes at all temperature levels when heating did not exceed 60 s. AH Plus and Pulp Canal Sealer can be considered suitable for warm root filling techniques.

Antibacterial and antibiofilm activity over time of GuttaFlow Bioseal and AH Plus

The sealers' antibacterial and antibiofilm activities against Enterococcus faecalis were evaluated by direct contact test (DCT) and confocal laser scanning microscopy (CLSM), respectively, after 1 day, and 1 and 4 weeks of aging. Cell viability was determined by adenosin triphosphate (ATP) assay after DCT. The parameters evaluated for the antibiofilm property were total biovolume and percentage of green cells in E.faecalis biofilms. The data from the bioluminescence ATP assay as well as the total biovolume and green percentage were analyzed by non-parametric tests, Kruskal-Wallis for global comparison and Kolmogorov-Smirnov for each two variables. Results of the DCT and CLSM for all parameters evaluated show that the antimicrobial activity of AH Plus decreased over time, whereas GuttaFlow Bioseal had an opposite property, increasing its antibacterial activity as the material aged.

Duration of Immersion and Type of Immersion Solution Distort the Outcome of Push-Out Bond Strength Testing Protocols

This study aimed to investigate the influence of immersion duration and the type of immersion solution on the outcome of push-out bond strength (POBS) tests. Root canals of 120 straight single-rooted teeth were instrumented to a diameter of 1.5 mm and irrigated with 5 mL of 3% NaOCl. Four horizontal slices with a thickness of 1 mm were cut, representing the mid-portion of the root. The specimens (n = 480) were irrigated with 17% ethylenediaminetetraacetic acid(EDTA) for 60 seconds, then twice with distilled water (DW) for 30 s each. The canals were filled with either AH Plus (Dentsply Sirona, Konstanz, Germany) or BioRoot RCS (Septodont, St. Maur-des-Fossés, France) (n = 240). Separated into four groups per type of sealer (n = 60), the specimens were incubated at 37 °C covered with gauze moistened in DW or phosphate-buffered saline (PBS) for either one or eight weeks. Dislodgement resistance was measured and POBS was calculated. Statistical analysis was performed using the analysis of variance (ANOVA) test and the Student–Newman–Keuls test (p = 0.05). AH Plus showed higher POBS when stored in PBS compared to DW, irrespective of the incubation period (p < 0.05). BioRoot RCS displayed higher POBS when stored in DW compared to PBS after eight weeks of incubation (p < 0.05). No difference was found after one week of incubation (p > 0.05). Irrespective of the sealer or the immersion solution, POBS decreased from one week to eight weeks (p < 0.05). Mixed failure modes were found in all groups irrespective of sealer, immersion medium, or immersion period. POBS decreased after a longer incubation time in both immersion solutions. Duration of immersion and the type of immersion solution had a significant impact on the outcome of the POBS testing protocol.

Effect of Different Irrigation Solutions on the Apical Sealing Ability of Different Single-cone Obturation Systems: An In Vitro Study

AIM

The aim of this study was to assess the effect of three root canal irrigants on the apical sealing ability of three single-cone obturation systems.

MATERIALS AND METHODS

One hundred maxillary central incisors were selected and their crowns were cut. The roots were divided into three experimental groups of 30 samples each, and one control group of 10 samples (5 positives and 5 negatives). Each experimental group was divided equally into three subgroups according to the obturation system. All root canals were instrumented using ProTaper Universal rotary system and irrigated with 3% sodium hypochlorite (Group 1), 2% chlorohexidine (Group 2), 3% hydrogen peroxide (Group 3). Finally, root canals were irrigated with 17% EDTA followed by distilled water, then obturated with a single-cone technique using gutta-percha/MTA Fillapex (Subgroup A), gutta-percha/ AH Plus (Subgroup B), and Resilon/Relseal SE (Subgroup C). The microleakage was assessed using linear dye penetration method and data were statistically analyzed.

RESULTS

Significant differences were found between all groups and subgroups (p < 0.005). When 3% of hydrogen peroxide was used, no leakage was observed with AH Plus sealer, and a high amount of leakage (5.82 ± 0.47 mm) was observed with Realseal SE. MTA Fillapex (0.49 ± 0.08 mm) and Realseal SE (1.11 ± 0.50 mm) showed the lowest amounts of leakage when 2% chlorohexidine and 3% sodium hypochlorite were used, respectively.

CONCLUSION

The type of irrigating solution and obturation system could affect the apical leakage value when single-cone obturation technique was used. AH Plus/gutta-percha obturation system showed no apical leakage when root canals were irrigated with 3% hydrogen peroxide. The using of 2% chlorohexidine improved sealing ability of MTA Fillapex/gutta-percha. The apical sealing ability of Realseal SE/Resilon decreased when 3% hydrogen peroxide or 2% chlorhexidine was used.

CLINICAL SIGNIFICANCE

Proper selection of irrigating solutions may positively influence the apical sealing ability of single-cone obturation systems.

An In Vitro Evaluation of Apical Leakage in Gutta-percha/ AH Plus and Resilon/Epiphany-filled Root Canals Using Two Dye Penetration Techniques

AIM

Aim of the present study was to evaluate the apical leakage in gutta-percha/AH plus and resilon/epiphany filled root canals using two dye penetration techniques.

MATERIALS AND METHODS

Sixty freshly extracted human single-rooted teeth were collected. The crown portion of each tooth was sectioned from the cementoenamel junction using a diamond disk. The canals were instrumented using Step back technique up to a caliber of 40. The roots were randomly divided into four experimental groups of 15 sample units each. All the groups are obturated using lateral compaction technique. Samples were placed in India ink and stored in an incubator for 7 days after which they were thoroughly washed under tap water and dried. The roots were divided into longitudinal splitting technique with diamond disks and using clearing technique was checked for linear dye penetration using stereomicroscope. The surfaces were scanned and surfaces with greatest dye penetration were measured by using De winter Biowizard software system.

RESULTS

The mean leakage for groups I, II, III, and IV are 2.31980, 2.68140, 4.11567, and 4.21047 respectively. One-way ANOVA was applied to the mean leakage scores of different groups, found a significant difference between mean leakage scores. F value of 3.266 and it was found to be significant with a p value of 0.028. Significant differences were obtained for mean comparisons of groups I and III, groups I and IV and groups III and IV. Further, between groups I and II, groups II and III, and groups III and IV no significant differences were observed.

CONCLUSION

In conclusion, gutta-percha/AH Plus sealed root canals showed lesser leakage than the Resilon Epiphany groups and there was no significant difference in the two different methodologies used for dye penetration.

CLINICAL SIGNIFICANCE

Tightly adapted endodontic filling material is one of the goals in successful clinical endodontics and Improvements in the adhesive technology have fostered attempts to reduce apical and coronal leakage by bonding to the root canal walls to obtain a solid monoblock.

In vitro Interrelationship between Apical Fill and Apical Leakage Using Three Different Obturation Techniques

AIM AND OBJECTIVES

To evaluate the apical fill in relation to apical leakage using three different obturating techniques - Single Cone, Ultrafil 3D, and lateral condensation.

MATERIALS AND METHODS

Sixty-six mandibular single-rooted premolar teeth were selected and were randomly assigned into three different groups of obturating techniques. The canals were prepared using 0.4/25 HyFlex CM (Coltene Endo) rotary system file and obturated with corresponding HyFlex CM Single Cone, Ultrafil 3D injectable technique, and lateral condensation. AH Plus (Dentsply, Detrey) has been used as the sealer. Twenty teeth each were assigned to the three experimental groups, and six teeth were used as positive and negative controls (3 in each group). Fluid filtration technique was used to determine the amount of apical leakage. The evaluation was done for 8 min at the interval of every 2 min. The same teeth were sectioned and a spectroscopic examination was done at 2 mm and 4 mm distance from the apices. The obtained data were statistically analyzed using analysis of variance test followed by post hoc turkeys test for multiple comparisons.

RESULTS

The mean apical leakage was maximum for lateral condensation when compared to the Single Cone and Ultrafil 3D. The amount of apical fill at 2 mm and at 4 mm was found to be more in the Single Cone than the other two techniques.

CONCLUSION

The present study concluded that Single Cone obturation technique exhibited more gutta-percha filled area in the canal which led to decreased apical leakage than Ultrafil 3D and lateral condensation techniques, proving to be more effective in achieving a complete three-dimensional apical seal.

Cytotoxicity of Different Concentrations of Three Root Canal Sealers on Human Mesenchymal Stem Cells

This study assessed the dose-dependent effect on the cytotoxicity of BioRoot RCS (BR) and Endosequence BC (BC) sealers in human bone marrow mesenchymal stem cells (hMSCs) compared to those of the AH Plus sealer. Cells were exposed to different dilutions of extracts from freshly prepared sealers (1:2, 1:8, 1:32). Unexposed cells acted as the negative control. Cytotoxicity was evaluated by an alamar blue assay. Cell morphology was analyzed by using scanning electron microscopy after exposure to the different sealers’ extracts. Statistical analysis was performed using a one-way analysis of variance and the Bonferroni post hoc test (p < 0.05). The cytotoxicities of BC and BR were less than that of AH Plus. In the presence of 1:2 BR, the cell proliferation was significantly lower than the control. At 1:8 and 1:32 concentrations, both the tricalcium silicate sealers led to similar cellular proliferation. Cells in BC and BR sealers’ extracts spread better than those in AH Plus extract.

Evaluation of Antimicrobial Efficacy of Root Canal Sealers against Enterococcus faecalis: A Comparative Study

AIM

The study aimed to evaluate the efficacy of root canal sealer's antimicrobial activity against Enterococcus faecalis.

MATERIALS AND METHODS

Root canal sealers with the brands Endoflas FS, AH Plus, and Tubli-Seal EWT were selected. Enterococcus faecalis organisms' zone of inhibition was measured. Tukey post hoc tests and one-way analysis of variance (ANOVA) were used to compare the data among study groups and within its group. The data were said to be statistically significant with an established p-value less than 0.05.

RESULTS

The maximum zone of inhibition (23.20 ± 1.202 mm) was shown by Endoflas FS sealer; AH Plus and Tubli-Seal showed the inhibition zone of (18.42 ± 1.023) and (16.88 ± 0.962) respectively, following Endoflas FS. The ANOVA test showed p < 0.0001, which is highly statistically significant. AH Plus and Endoflas FS showed a statistically significant difference of 0.04 and 0.001 in between groups, and there was no statistically significant difference in the Tubli-Seal group from Tukey post hoc test.

CONCLUSION

The study showed that Endoflas FS sealer has a significant antimicrobial effect against E. faecalis.

CLINICAL SIGNIFICANCE

In clinical situation, despite perfect che-momechanical root canal preparation, persistence of microorganisms may reinfect the root canal. Therefore, endodontic root canal sealers play a major role in the eradication of bacteria. The polymicrobial nature of endodontic infection plays a main role during the usage of endodontic sealer with antimicrobial agents, which in turn reduces the failure of endodontic treatment.

An In vitro Comparison of Pushout Bond Strength of Resilon with MetaSEAL and AH Plus Sealers

Aim

The aim of this study is to evaluate and compare the pushout bond strengths of Resilon with two different sealers: Resilon/MetaSEAL (methacrylate based) and Resilon/AH Plus (an epoxy resin-based sealer).

Materials and Methods

Forty single canal anterior teeth were decoronated at cementoenamel junction and standardized to 10 ± 1 mm length. Working length was determined followed by biomechanical preparation. Then, the specimens were randomly assigned into two groups of 20 teeth each based on the sealer used with Resilon. All canals were obturated using single-cone obturation technique. Root samples were prepared for pushout testing. The universal testing machine gave the debonding force for individual specimen. This was done for all the specimens.

Statistical Analysis

This was done by using unpaired Student's t-test.

Results

The roots filled with Resilon/MetaSEAL had higher bond strength (1.49 ± 0.09 MPa) compared to Resilon/AH Plus (0.90 ± 0.04 MPa) group. The difference in bond strength was statistically significant (P = 0.0000).

Conclusion

Through this pushout bond strength test, it could be noted that MetaSEAL did appear to bond to the dentin and could be used as a potential endodontic sealer.

Efficacy of different irrigation regimes on the push-out bond strength of various resin-based sealers at different root levels: An in vitro study

Aim:

This study aims to evaluate and compare the efficacy of various irrigation regimens on push-out bond strength of AH Plus/gutta-percha, Real Seal/Resilon, and MetaSeal/gutta-percha at three different root levels.

Materials and Methods:

Single-rooted mandibular premolars (n = 120) were prepared and divided into four groups (n = 30) based on irrigation regimen used: I: 5.25% sodium hypochlorite (NaOCl)-17% ethylenediaminetetraacetic acid (EDTA); II: 5.25% NaOCl-2.25% Peracetic acid (PAA); III: 5.25% NaOCl-18% 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) (Etidronic Acid); and IV: Distilled Water. Each group was further divided into three subgroups (n = 10); A: AH Plus/gutta-percha; B: MetaSEAL/gutta-percha; C: RealSeal/Resilon. After obturation, roots were sectioned at 3 levels and push-out tests were performed. One-way ANOVA with post hoc Tukey-honestly significant difference tests were applied to assess the significance among various groups.

Results:

Among irrigants, 2.25% PAA showed significantly lower values when compared with rest of the irrigants. There was no significant difference found among EDTA and HEBP. The push-out bond strength of AH Plus was significantly higher among all sealers. The bond strength values were significantly decreased in apico-coronal direction.

Conclusions:

There was superior efficacy of EDTA and HEBP on the bond strength of AH Plus at apical root level when compared with other irrigants and sealers at various root levels.

Assessment of Marginal Adaptation and Sealing Ability of Root Canal Sealers: An in vitro Study

AIM

This study aims to compare the marginal adaptation and sealing ability [mineral trioxide aggregate (MTA)-Fillapex, AH Plus, Endofill sealers] of root canal sealers.

MATERIALS AND METHODS

In the present study, the inclusion criteria include 45 single-rooted extracted mandibular premolar teeth, with single canal and complete root formation. The sectioning of the samples was done at the cementoenamel junction using a low-speed diamond disc. Step-back technique was used to prepare root canals manually. The MTA-Fillapex, AH Plus, and Endofill sealers were the three experimental sealer groups to which 45 teeth were distributed. Under scanning electron microscope (SEM), marginal gap at sealer and root dentin interface were examined at coronal and apical halves of root canal.

RESULTS

Among the three maximum marginal adaptations were seen with AH Plus sealer (4.10 ± 0.10) which is followed by Endofill sealer (1.44 ± 0.18) and MTA-Fillapex sealer (0.80 ± 0.22). Between the coronal and apical marginal adaptation, significant statistical difference (p = 0.001) was seen in AH Plus sealer. When a Mann-Whitney U-test was done on MTA-Fillapex sealer vs AH Plus sealer and AH Plus sealer vs Endofill sealer, there was a statistically significant difference (p < 0.05) found between the above two groups at coronal and apical third.

CONCLUSION

The present study proves that AH Plus sealer has a better marginal adaptation when compared with other sealers used.

CLINICAL SIGNIFICANCE

For sealing space of crown wall and main cone in root canal treatment, sealers play an important role. The other advantages of sealers are that they are used to fill voids and irregularities in root channel, secondary, lateral channels, and space between applied gutta-percha cones and also act as tripper during filling.

Stereomicroscopic Dye Leakage Measurement of Six Different Root Canal Sealers

INTRODUCTION

Hermetic sealing of the root canal is the most desirable outcome of any root canal treatment, but almost always the filling of the root canal is defective, which is a multifactorial outcome. One such factor majorly influencing the obturation is the root canal sealer used.

AIM

The present study was done for evaluating microleakage in different root canal sealers.

MATERIALS AND METHODS

Sixty extracted human single rooted teeeth were used in this in-vitro study. Sealers tested for microleakage in this study were zinc oxide eugenol based sealer, Sealapex, AH Plus, MTA Plus, EndoRez, Endosequence BC. All the specimens were examined under stereomicroscope for microleakage and the obtained data were statistically analysed using One-way ANOVA test and Tukey's multiple comparision tests using the software GraphPad Prism 7.02.

RESULTS

The Endosequence BC group showed the least dye leakage and the highest leakage was seen in Zinc oxide Eugenol based sealer.

CONCLUSION

Bio ceramic salers being hydrophilic show better sealing ability compared to resin based and eugenol based sealers.

Post space preparation timing of root canals sealed with AH Plus sealer

OBJECTIVES

To determine the optimal timing for post space preparation of root canals sealed with epoxy resin-based AH Plus sealer in terms of its polymerization and influence on apical leakage.

MATERIALS AND METHODS

The epoxy polymerization of AH Plus (Dentsply DeTrey) as a function of time after mixing (8, 24, and 72 hours, and 1 week) was evaluated using Fourier transform infrared (FTIR) spectroscopy and microhardness measurements. The change in the glass transition temperature (Tg ) of the material with time was also investigated using differential scanning calorimetry (DSC). Fifty extracted human single-rooted premolars were filled with gutta-percha and AH Plus, and randomly separated into five groups (n = 10) based on post space preparation timing (immediately after root canal obturation and 8, 24, and 72 hours, and 1 week after root canal obturation). The extent of apical leakage (mm) of the five groups was compared using a dye leakage test. Each dataset was statistically analyzed by one-way analysis of variance and Tukey's post hoc test (α = 0.05).

RESULTS

Continuous epoxy polymerization of the material with time was observed. Although the Tg values of the material gradually increased with time, the specimens presented no clear Tg value at 1 week after mixing. When the post space was prepared 1 week after root canal obturation, the leakage was significantly higher than in the other groups (p < 0.05), among which there was no significant difference in leakage.

CONCLUSIONS

Poor apical seal was detected when post space preparation was delayed until 1 week after root canal obturation.

Comparative evaluation of apical microleakage in immediate and delayed postspace preparation using four different root canal sealers: An in vitro study

BACKGROUND

Endodontically treated teeth often lack sufficient support for a permanent restoration. During post space preparation, it is important not to disturb the integrity of the apical seal.

AIM

This study compared the effect of immediate versus delayed post space preparation on the apical seal using four different sealers.

MATERIALS AND METHODS

One hundred and thirty single rooted teeth were biomechanically prepared and obturated with single cone gutta-percha and 4 sealers: Endoflas FS, AH Plus, Gutta flow and MTA. Teeth were divided randomly into eight groups, post spaces were prepared using Gates Glidden drills immediately for group I, III, IV and VII. For groups II, IV, VI and VIII prepared after storage of the specimens in 100% humidity for one week. The samples were kept in methylene blue dye, centrifuged at 3000 rpm for 3 min sectioned and then measured under stereomicroscope for apical leakage.

STATISTICAL ANALYSIS

The data was analysed using one way ANOVA and post hoc Tukey test.

RESULTS

All the specimens showed dye leakage, and a statistically significant difference was seen among all the groups (P > 0.05) except Gutta flow.

CONCLUSION

Less leakage is seen when post space is prepared immediately.

Effect of Calcium Hydroxide Based Intracanal Medicaments on the Apical Sealing Ability of Resin Based Sealer and Guttapercha Obturated Root Canals

INTRODUCTION

Calcium Hydroxide (CH) is one of the most commonly used intracanal medicaments which can be used with various vehicles.

AIM

The aim of this in vitro study was to evaluate the effect of three CH based intracanal medicaments on the apical sealing ability of AH Plus - guttapercha obturation.

MATERIALS AND METHODS

Crowns of 100 extracted single rooted human teeth were sectioned at the Cemento-Enamel Junction (CEJ) to a standardized length. The root canals were instrumented upto ISO size 40 using step back technique and the specimens were randomly divided into two control and four experimental groups. The control groups were not medicated. Specimens in positive control group (Group I) were obturated with guttapercha without placing sealer and in negative control group (Group II) were obturated with guttapercha and AH Plus sealer. Among the experimental groups, specimens of Group III were not medicated while groups IV, V and VI were medicated with CH-saline, CH-2% Chlorhexidine (CHX) and Vitapex respectively for a period of 14 days. The medicaments were removed from the specimens and the teeth were obturated with AH Plus sealer and guttapercha using lateral compaction technique. The specimens were immersed in India ink dye, demineralized and diphanized. The extent of dye penetration was assessed using a 10X stereomicroscope. Data obtained was statistically analyzed by one-way ANOVA (p<0.05) followed by Post-hoc Tukey test.

RESULTS

Amongst the three CH medicaments, CH-2% CHX when used as an intracanal medicament showed a significantly higher microleakage as compared to the other groups with p<0.001. The microleakage values between the remaining groups were not statistically significant.

CONCLUSION

Under the conditions of this study it was concluded that all groups with or without intracanal medicament showed apical leakage. The vehicle used to carry CH may significantly influence the apical sealing ability of guttapercha - AH Plus obturated canals.

Retreatability of two endodontic sealers, EndoSequence BC Sealer and AH Plus: a micro-computed tomographic comparison

OBJECTIVES

Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer) have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT) analysis.

MATERIALS AND METHODS

Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and a post-hoc Tukey test. Fisher exact tests were performed to analyze the ability to regain patency.

RESULTS

There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group.

CONCLUSION

The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform.

A comparison of apical sealing ability between GuttaFlow and AH plus: An in vitro study

Aims:

The present study aimed to compare apical sealing ability between GuttaFlow and AH Plus.

Materials and Method:

Eighty extracted human maxillary anterior teeth with fully formed apex and straight root were collected for this study. The root canals were cleaned and shaped using a standard step back preparation to size 60# master apical file at the established working length and divided into four groups: Group 1, GuttaFlow sealer with gutta-percha; Group 2, AH Plus sealer with gutta-percha; Group 3, positive control group (Teeth were instrumented and left without obturation); Group 4, negative control group (Teeth were totally coated with nail varnish) Dye leakage was carried out. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.

Results:

The GuttaFlow group had a mean leakage of 1.38 mm whereas AH Plus had a mean of 1.425 mm. The standard deviation of GuttaFlow and AH Plus were 0.3861 and 0.3226, respectively. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.

Conclusion:

None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal. GuttaFlow and AH Plus showed no statistically significant difference in microleakage; the better result was shown by GuttaFlow.

An in-vitro comparative study for assessment of apical sealing ability of Epiphany/AH Plus sealer with Resilon/gutta-percha root canal filling materials

AIMS AND OBJECTIVES

Endodontic treatment is directed to eliminate microbial challenges from the root canal system and to create a complete seal. The aim of this study was to assess the apical sealing ability of resin-based Epiphany-Resilon root canal filling system and to compare it with the sealing abilities of different combinations of AH Plus, gutta-percha, Epiphany, and Resilon.

MATERIALS AND METHODS

One hundred extracted human maxillary incisor roots were treated endodontically. The samples were divided into groups A, B, C, and D, with each group containing 25 samples. Group A: Canals obturated with gutta-percha and AH Plus sealer; Group B: Canals obturated with Resilon and Epiphany; Group C: Canals obturated with gutta-percha and Epiphany; Group D: Control group canals obturated with gutta-percha without a sealer. The sealing ability of each of the obturation techniques was tested using the dye penetration method followed by the clearing method using alcohol. Stereo microscope was used to measure the extent of dye penetration. Statistical data analysis was performed using analysis of variance and Tukey tests.

RESULTS

Microleakage was found in all the four groups. Apical extent of mean microleakage was maximum for gutta-percha, followed by Gutta-percha + AH-plus and Gutta-percha + Epiphany, and the least with Resilon + Epiphany. Statistically significant difference (P < 0.01) was seen in the apical leakage.

CONCLUSION

All the samples tested showed microleakage. The "Epiphany soft resin endodontic obturation system" showed a superior result compared to other obturation materials.

The comparison between two irrigation regimens on the dentine wettability for an epoxy resin based sealer by measuring its contact angle formed to the irrigated dentine

AIM

The aim was to assess the influence of two irrigation regimens having ethylenediaminetetraacetic acid (EDTA) and ethylenediaminetetraacetic acid with cetrimide (EDTAC) as final irrigants, respectively, on the dentine wettability for AH Plus sealer by comparing its contact angle formed to the irrigated dentine.

MATERIALS AND METHODS

Study samples were divided into two groups (n = 10). The groups were irrigated with 3% sodium hypochlorite (NaOCl) solution followed by either 17% EDTA or 17% EDTAC solution. AH Plus was mixed, and controlled volume droplet (0.1 mL) of the sealer was placed on the dried samples. The contact angle was measured using a Dynamic Contact Angle Analyzer and results were analyzed using SPSS 21.0 and 2 sample t-test.

RESULTS

There was a significant difference in the contact angle of AH Plus formed to the dentine irrigated with the above two regimens. AH Plus showed significantly lower contact angle with the regimen having EDTAC as a final irrigant than the one with EDTA (P < 0.05).

CONCLUSION

An irrigation regimen consisting of NaOCl with either EDTA or EDTAC solution as a final irrigant influences the dentine wettability and contact angle of a sealer. EDTAC as a final irrigant facilitates better dentin wettability than EDTA for AH Plus to promote its better flow and adhesion.

Effect of Peracetic Acid as A Final Rinse on Push Out Bond Strength of Root Canal Sealers to Root Dentin

BACKGROUND

Smear layer which was formed during the instrumentation of root canals hinders the penetration of root canal sealers to root dentin and affect the bond strength of root canal sealers to root dentin. Final irrigant such as demineralizing agents are used to remove the inorganic portion of the smear layer. In the present study, peracetic acid used as a final rinse, to effect the bond strength of root canal sealers to root dentin.

AIM

The purpose of the present study was to evaluate the efficacy of peracetic acid as a final irrigant on bond strength of root canal sealers to root dentin.

MATERIALS AND METHODS

Sixty six freshly extracted human single rooted mandibular premolars were used for this study. After decoronation the samples were instrumented with Protaper upto F3 and irrigated with 5.25% NaOcl. The teeth were then divided into three groups based on final irrigant used: Group-1(control group) Canals were irrigated with distilled water. Group-2: Canals were irrigated with peracetic acid. Group-3: Canals were irrigated with smear clear. Each group was further divided into three subgroups (n=30) based on the sealer used to obturate the canals. Subgroup-1: kerr, Subgroup-2: Apexit plus, Subgroup-3: AH PLUS. Each sealer was mixed and coated to master cone and placed in the canal. The bonding between sealer and dentin surface was evaluated using push out bond strength by universal testing machine. The mean bond strength values of each group were statistically evaluated using Two-way ANOVA followed by Tukey post-hoc test.

RESULTS

Significant difference was found among the bond strength of the sealers. But, there is no statistically significant difference between the groups irrigated with peracetic acid and smear clear compared to control group. AH Plus showed highest bond strength irrespective of the final irrigant used.

CONCLUSION

Peracetic acid when employed as final irrigant improved the bond strength of root canal sealers compared to control group but not statistically significant than smear clear.

Quantitative microleakage analysis of root canal filling materials in single-rooted canals

The purpose of this study was to analyze the sealing ability of different root canal filling materials over a 6-week period using a glucose penetration model. Forty-six recently extracted human premolars were used in this study. The root canals were enlarged to 40/0.06. Prepared canals were randomly assigned into four groups (n = 10) as follows: Group 1, Gutta-Percha (GP)/AH Plus with cold lateral compaction; Group 2, GP/AH Plus with continuous wave compaction; Group 3, RealSeal SE obturation system; and Group 4, OrthoMTA. The remaining specimens were used as positive and negative controls, and all specimens underwent thermocycling (10,000; 5-55 °C). The sealing ability of all samples was evaluated at 24 h, 1, 2, 4, and 6 weeks using a quantitative glucose leakage model, and scanning electron microscope (SEM) images were taken. A mixed effect analysis using R statistical language was performed. Groups 1, 2, and 4 showed low leakage levels during experimental periods. Group 3 showed low leakage levels for the first 2 weeks; however, the leakage level was significantly increased after 2 weeks compared to negative control group (p < 0.05). In the SEM results, Group 3 showed imperfect dentin bonding, whereas Group 4 showed calcium silicate hydrate short tags, which are formed at the access of the dentin tubules. GP/AH Plus and OrthoMTA showed less microleakage than RealSeal SE obturation system when used as root canal filling materials. Traditional GP/AH Plus sealer and the newly developed OrthoMTA are more appropriate for ideal sealing of the root canals.