An Evaluation of Wetting and Adhesion of Three Bioceramic Root Canal Sealers to Intraradicular Human Dentin

A Literature Review of the Effect of Heat on the Physical-Chemical Properties of Calcium Silicate-Based Sealers

INTRODUCTION

Recently, calcium silicate-based sealers (CSSs) have gained popularity in endodontic practice due to their biocompatibility and antimicrobial properties. They are considered viable alternatives to epoxy resin-based sealers. With the increased use of CSSs and warm vertical compaction techniques in root canal treatment, evaluating the impact of heat on CSSs properties is essential, therefore this review aimed to present a qualitative synthesis of available in vitro studies assessing the impact of heat on the physical-chemical properties of CSSs.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 guidelines, a systematic advanced electronic search was performed in Scopus, Embase, Medline (via PubMed), Web of Science, and Cochrane databases in November 2023 and updated in April 2024. In vitro studies that evaluated the physical-chemical properties of CSSs were eligible. PRILE 2021 guidelines were used for the assessment of the risk of bias-included studies.

RESULTS

The search identified a total of 6421 preliminary results and 10 studies were included for qualitative assessment. Eleven different physiochemical properties were assessed by the included studies. Setting time and flow were the most evaluated property among the studies. A qualitative synthesis of the evidence on each property is presented.

CONCLUSIONS

Based on the in vitro studies assessed in the present systematic review, results reveal that exposing CSSs to heat can accelerate their setting time, reduce their flow, and increase their film thickness. Concerns persist regarding solubility, viscosity, radiopacity, dimensional change, microhardness, porosity, and compressive strength, requiring further research. Certain CSSs, such as MTA Fillapex and Endosequence BC sealer HiFlow, show minimal changes under heat, making them potential candidates for warm filling techniques.

Calcium Silicate-Based Sealer Dentinal Tubule Penetration-A Systematic Review of In Vitro Studies

The aim of this systematic review was to perform a qualitative synthesis of in vitro studies which evaluate and compare the penetration of calcium silicate-based sealers into dentinal tubules. A systematic advanced search was performed in Scopus, Embase, Medline (via PubMed), Web of Science, and Cochrane databases on the 1 December 2022. In vitro studies that compared the tubular penetration of at least two calcium silicate-based sealers in extracted human teeth were eligible. PRILE 2021 guidelines were used for the assessment of the risk of bias included studies. The search identified a total of 680 preliminary records, among which 12 studies were eligible for review. The most used methodology to evaluate sealer penetration was the use of a fluorochrome together with the tested sealers and the analysis of their penetration under confocal laser microscopy. Regarding the results of the included studies, calcium silicate-based sealers exhibit a favorable dentinal tubule penetration. Tubular penetration, however, can be affected by factors such as the irrigation protocol, sealer activation, the filling method used, and root canal morphology. EndoSequence BC Sealer showed the highest sealer penetration among the tested sealers. The influence of different fluorochromes on the results of dentinal tubule penetration studies should also be further explored. The in vitro nature of the included studies limits the applicability of the results into the clinical setting. Prospero registration: CRD42022383896.

A Micro-CT Analysis of Initial and Long-Term Pores Volume and Porosity of Bioactive Endodontic Sealers

The evaluation of the porosities within the interface of root canals obturated with endodontics materials is extremely important for the long-term success of endodontic treatments. The aim of this study was to compare initial and long-term volume of pores (total, open, closed) and porosity (total, regional) of three bioactive endodontic sealers: GuttaFlow Bioseal, Total Fill BC Sealer, and BioRoot RCS. Root canals were obturated with three “bioactive” sealers using the single-cone technique. The volume of open and closed pores and porosity were calculated using a micro-computed tomography (MCT) method. The measurements were performed after 7 days (initial) and after 6 months (long-term) of incubation. Statistical significance was considered at p < 0.05. The total volume of pores remained unchanged after the 6-month storage. GuttaFlow Bioseal exhibited significantly higher long-term volume in open pores than Total Fill BC Sealer. The total porosity in all the tested sealers presented no statistically significant change after the 6-month storage, except for BioRoot RCS. The total porosity values of this latter material significantly increased after long-term incubation, especially in the apical region. In conclusion, the use of bioactive sealers with excessive tendency to create porosities both in shorth- and long-term periods of storage may compromise the long-term success of endodontic treatments.

Effect of Chloroform Application on Roughness and Wettability of the Root Canal Walls in Endodontic Retreatment

Statement of the Problem

The success of root canal therapy depends on root canal irrigation, disinfection, and sealing of root canal. Wettability and roughness of root dentine surface are important factors in root canal disinfection and sealing.

Purpose

This study aimed to assess the effect of chloroform application on roughness and wettability of the root canal walls in endodontic retreatment.

Materials and Method

This in vitro experimental study evaluated 70 sound extracted human anterior teeth. The specimens were then randomly assigned to 7 groups as follows: Chloroform (group 1), 1g gutta percha+chloroform (group 2), 2g gutta percha+ chloroform (group 3), 1g gutta percha+ 1g sealer+ chloroform (group 4), 2g gutta perch+ 2g sealer+chloroform (group 5), 1g sealer + chloroform (group 6) and 2g sealer + chloroform (group 7). One drop of distilled water was placed on each tooth to measure the contact angle and wettability. Photographs were obtained of an area measuring 50×50 µm² in three directions under an atomic force microscope to measure the roughness. The tooth blocks were exposed to the abovementioned mixtures for 10 min, and then rinsed with saline. The roughness and wettability of each sample were measured before and after treatment. Data was analyzed using one-way ANOVA and Tukey's test.

Results

The roughness of all groups significantly decreased following treatment, except for groups 1 and 4. The contact angle increased in all groups after treatment (except for the chloroform group), which indicated decreased wettability. The roughness and the contact angle have shown no correlation.

Conclusion

Application of chloroform for removal of gutta-percha and sealer in endodontic retreatment decreases the roughness and wettability of dentine.

The Effect of Sealer Application Methods on Voids Volume after Aging of Three Calcium Silicate-Based Sealers: A Micro-Computed Tomography Study

During obturation, air voids are undesirable as they may provide shelter for microorganisms or passage for fluids. This study aimed to compare the occurrence of voids between three calcium silicate-based sealers (CSBSs) (MTA-Fillapex, BioRoot-RCS, Bio-C) and the change in their volume after aging. In addition, we aimed to compare voids when using two sealer application methods: lentulo-spiral (LS) and gutta-percha (GP) cone. Thirty extracted mandibular premolars (n = 30) were endodontically prepared and obturated using single GP cone (SGPC) technique. Each sealer was applied to 10 teeth (n = 10) using LS or GP. Micro-computed tomography (micro-CT) was used to quantify the volume of root filling and voids before and after 8-week storage in a phosphate-rich medium. The percentage of root filling and voids were compared between the groups using a Mann–Whitney U test and Kruskal–Wallis test with a Bonferroni correction. Before aging, the percentages of root filling volume after obturation were comparable with no significant differences between sealers (p = 0.325) or application methods (p = 0.950). After aging, the voids’ volume increased significantly in all sealers (p ≤ 0.05). However, no significant differences were found between sealers (p = 0.302). In conclusion, voids in CSBSs may not reduce in size with aging; hence, SGPC should be carefully selected for suitable cases.

Comparison of calcium and hydroxyl ion release ability and in vivo apatite-forming ability of three bioceramic-containing root canal sealers

OBJECTIVE

Bioceramic-containing root canal sealers promote periapical healing via Ca²⁺ and OH^- release and apatite formation on the surface. This study aimed to compare Ca²⁺ and OH^- release and in vivo apatite formation of three bioceramic-containing root canal sealers: EndoSequence BC sealer (Endo-BC), MTA Fillapex (MTA-F), and Nishika Canal Sealer BG (N-BG).

MATERIALS AND METHODS

Polytetrafluoroethylene tubes filled with sealers were immersed in distilled water for 6 and 12 h and for 1, 7, 14, and 28 days to measure Ca²⁺ and OH^- release. Additionally, tubes filled with sealers were implanted in the backs of rats for 28 days, and in vivo apatite formation was analyzed using an electron probe microanalyzer.

RESULTS

Endo-BC released significantly more Ca²⁺ than the other sealers at 6 and 12 h and 1 day. Ca²⁺ release was significantly lower from N-BG than from Endo-BC and MTA-F at 14 and 28 days. OH^- release was significantly higher from Endo-BC than from the other sealers throughout the experiment, except at 1 day. OH^- release was lower from N-BG than from MTA-F at 6 h and 7 days. Only Endo-BC implants exhibited apatite-like calcium-, phosphorus-, oxygen-, and carbon-rich spherulites and apatite layer-like calcium- and phosphorus-rich, but radiopaque element-free, surface regions.

CONCLUSIONS

Ca²⁺ and OH^- release is ranked as follows: Endo-BC > MTA-F > N-BG. Only Endo-BC demonstrated in vivo apatite formation.

CLINICAL RELEVANCE

Endo-BC could promote faster periapical healing than MTA-F and N-BG.

Calcium Silicate-Based Root Canal Sealers: A Narrative Review and Clinical Perspectives

Over the last two decades, calcium silicate-based materials have grown in popularity. As root canal sealers, these formulations have been extensively investigated and compared with conventional sealers, such as zinc oxide-eugenol and epoxy resin-based sealers, in in vitro studies that showed their promising properties, especially their biocompatibility, antimicrobial properties, and certain bioactivity. However, the consequence of their higher solubility is a matter of debate and still needs to be clarified, because it may affect their long-term sealing ability. Unlike conventional sealers, those sealers are hydraulic, and their setting is conditioned by the presence of humidity. Current evidence reveals that the properties of calcium silicate-based sealers vary depending on their formulation. To date, only a few short-term investigations addressed the clinical outcome of calcium silicate-based root canal sealers. Their use has been showed to be mainly based on practitioners' clinical habits rather than manufacturers' recommendations or available evidence. However, their particular behavior implies modifications of the clinical protocol used for conventional sealers. This narrative review aimed to discuss the properties of calcium silicate-based sealers and their clinical implications, and to propose rational indications for these sealers based on the current knowledge.

Comparison of bacterial microleakage of three bioactive endodontic sealers in simulated underwater diving and aviation conditions

BACKGROUND

Bacterial microleakage is an important cause of apical periodontitis and endodontic treatment failure. This study aimed to assess the bacterial microleakage of nano-mineral trioxide aggregate (nano-MTA) as a sealer, Endoseal MTA, and GuttaFlow Bioseal sealers in atmospheric pressure, and simulated underwater diving and aviation conditions.

METHODS

In this in vitro, experimental study, 180 extracted single-rooted teeth were cleaned and shaped, and were then randomly divided into three groups for single-cone obturation using Endoseal MTA, GuttaFlow Bioseal, or nano-MTA as a sealer. Each group was then randomly divided into three subgroups, and subjected to ambient atmospheric pressure, 2 atm pressure (to simulate underwater diving), and 0.5 atm pressure (to simulate aviation) using a custom-made pressure chamber. The teeth then underwent microbial leakage test using Streptococcus mutans (S. mutans), and the percentage of samples showing microleakage was recorded for up to 1 month, and analyzed using the Chi-square test.

RESULTS

The three sealer groups were significantly different regarding bacterial microleakage (P < 0.05). The nano-MTA group showed significantly higher microleakage after 15 days than the other two groups (P = 0.006). The effect of pressure on bacterial microleakage was not significant in any sealer group (P > 0.05).

CONCLUSION

Within the limitations of this in vitro study, it may be concluded that single-cone obturation technique using nano-MTA as a sealer results in lower resistance to bacterial microleakage compared with the use of GuttaFlow Bioseal, and Endoseal MTA. Pressure changes in simulated underwater diving and aviation conditions had no significant effect on bacterial microleakage. Trial Registration Number This is not a human subject research.

Evaluation and comparison on the wettability of three root canal sealers after three different irrigant activation techniques: An in vitro study

Background

Wettability of root canal sealers to the root canal wall plays a significant role in the attainment of a fluid-tight seal.

Aims

This study aimed to evaluate and compare the wettability of three different root canal sealers on the root canal walls after three different irrigant activation techniques using the contact angle meter.

Subjects and Methods

Thirty-six single-rooted mandibular premolars after decoronation and cleaning and shaping up to size #35 were randomly divided into three groups with 12 samples in each group (n = 12) based on the different activation techniques: Group I (passive irrigation with side-vented needle), Group II (manual dynamic agitation), and Group III (passive ultrasonic irrigation). Root segments were split longitudinally and were subdivided into three subgroups based on the root canal sealers tested with four samples in each subgroup (n = 4): Subgroup A (Tubliseal EWT), Subgroup B (AH Plus), and Subgroup C (Endosequence BC sealer). A controlled volume droplet of sealer was placed on each specimen and was subjected to the contact angle meter.

Statistical Analysis

Data were statistically analyzed using the one-way ANOVA and Tukey's post hoc test at a significance level of 0.05 (P < 0.05).

Results

A statistically significant difference was seen among all the groups and subgroups with the highest contact angle value for Group III and Subgroup C and the least value for Group I and Subgroup A.

Conclusions

Passive irrigation with side-vented needle and Tubli-Seal EWT showed better wettability on dentin.