Comparative Evaluation of Retreatability of Endodontically Treated Teeth using AH 26, Fluoride Varnish and Mineral Trioxide Aggregate-based Endodontic Sealers

Retreatability of calcium silicate-based sealers based on micro-computed tomographic evaluation - A systematic review

Introduction

Endodontic retreatment procedures with calcium silicate-based sealers (CSS) have been receiving greater credibility in clinically challenging situations. The objective of this systematic review was to analyze the published in vitro studies for the retrievability of CSS in comparison to resin-based sealers evaluated using micro-computed tomography (micro-CT) in terms of the volume of the residual root canal filling materials, time taken, efficacy of the solvent, and different systems used during the retreatment procedure.

Methods

The study protocol was registered in the International Prospective Register of Systematic Reviews and conducted in adherence to PRISMA 2020 checklist. Accordingly, an electronic literature search was done to identify studies published in English language, within the time frame from January 2004 to June 2024. The search was conducted through popular databases including PubMed (Medline - National Library of Medicine), Scopus (Science Direct), EMBASE and Google Scholar following the inclusion and exclusion criteria answering the research question in focus.

Results

After thorough scrutiny, 15 studies qualified for the systematic review. Following retreatment, in all of the studies pre-treatment working length was achieved, with both the types of endodontic sealers. However, none of the micro-CT studies reported complete removal of endodontic filling material from the root canals. Irrespective of the sealer type used, within each root canal, apical third had the greatest amount of remaining filling material, followed by the middle and coronal thirds.

Conclusions

Retreatment of canals obturated with bioceramic sealers is feasible in most cases using traditional instruments and techniques. Active irrigation and supplemental mechanical removal, which employs lasers, XP-Finisher, and ultrasonics, adds advantage to maximize material removal.

Effectiveness of Two Endodontic Instruments in Calcium Silicate-Based Sealer Retreatment

The objective of the present in vitro work was to investigate the effectiveness and time required for the removal of calcium silicate-based sealer using two rotary retreatment systems. Sixty extracted, single-canal, lower premolars were used. After obturation using the single-cone technique with calcium silicate-based sealer, samples were divided into four groups according to the technique of desobturation: Group 1 (G1): D-Race; Group 2 (G2): D-Race followed by the use of XP-Endo Finisher R; Group 3 (G3): Protaper Universal Retreatment; and Group 4 (G4): Protaper Universal Retreatment followed by the use of XP-Endo Finisher R. Cone beam computed tomography (CBCT) images were used to calculate the remaining filling materials at the middle and apical thirds. Times required to perform each method were recorded. Scanning electron microscopy (SEM) and digital microscopy were used to evaluate the remaining filling materials. Data were statistically analyzed using the t-test and one way ANOVA on ranks tests. No statistically significant difference was found between G1 and G3 after CBCT observations (p > 0.05). Xp-Endo Finisher R significantly increased the ability to remove materials regardless of the initially used retreatment system (p < 0.05). Statistically significant longer time was found in G3 and G4 compared to G1 and G2, respectively (p < 0.05), to reach the full working length. No retreatment system was able to totally remove the calcium silicate-based sealer from the root canal at the middle and apical thirds (p > 0.05). Digital microscopy demonstrated that the residual materials were the remaining sealers on the canal walls. SEM showed the mineral depositions of calcium silicate materials onto the canal walls and into the dentinal tubules. However, that calcium silicate materials provide mineral deposition into the dentinal tubules might indicate that the traditional irrigants could not be sufficient to remove calcium silicate-based materials from the root canal, and other agents should be used to make retreatment considerably easier.

Retrievability of bioceramic-based sealers in comparison with epoxy resin-based sealer assessed using microcomputed tomography: A systematic review of laboratory-based studies

Aim:

The objective was to evaluate the retrievability of bioceramic sealers in comparison with epoxy resin-based sealers assessed using microcomputed tomography.

Materials and Methods:

Four reviewers independently conducted a systematic literature search in four electronic databases. The risk of bias was assessed using modified Joanna Briggs Institute Critical Appraisal tools for Quasi-Experimental Studies.

Results:

Ten articles were included in this review and all had a moderate risk of bias. The results across the included articles were inconsistent with some indicating easier/difficult removal of bioceramic sealers, while others indicate no difference. The studies varied in terms of the type of bioceramic sealer used, root canal anatomy, and retreatment techniques followed. Due to heterogeneity, only a qualitative analysis was performed and no meta-analysis was conducted.

Conclusion:

The quality of evidence is low and no definitive conclusion could be derived regarding the retrievability of bioceramic sealer/AH plus sealer from the root canals during retreatment procedures.