Microscopic analysis of the quality of obturation and physical properties of MTAFillapex

The use of sonic and ultrasonic activation of endodontic sealer to improve sealer filling quality in the root canal: a scoping review

This scoping review aimed to map whether the use of sonic and ultrasonic methods to activate the endodontic sealer improves the sealer filling quality in the root canal, considering the bond strength and intratubular penetration to the root dentin as evaluation criteria. The study protocol was prospectively registered and is available online ( https://osf.io/x5fma/ ). Reporting was based on PRISMA Extension for Scoping Reviews. The search was performed in Embase, PubMed, Scopus, and Web of Science. We selected studies without time and language restrictions that used sonic or ultrasonic methods to activate endodontic sealer, whose outcomes were bond strength and intratubular penetration. Three researchers independently selected the articles and collected data. Of 1422 articles, 19 were read in full and 13 studies were included. The vast majority of studies opted for direct activation of the endodontic sealer. The most investigated sealers were the epoxy resin-based sealers, and the ultrasonic activation method was the most explored. For the bond strength outcome, there was a trend toward higher values when the sealer was activated ultrasonically, but the findings seem to be divergent. The sonic activation was not effective for its intended purpose. For the outcome of intratubular penetration, the vast majority of studies indicate that the use of sonic and ultrasonic methods to activate the endodontic sealer is capable of increasing intratubular penetration. The use of sonic and ultrasonic methods to directly activate the endodontic sealer can increase the intratubular penetration of the sealer, but their benefits on the bond strength are uncertain.

Influence of bioceramic sealers on dentinal tubule penetration and antimicrobial effectiveness: a systematic review and meta-analysis of in vitro studies

The aim of this systematic review and meta-analysis (SRM) was to evaluate whether bioceramic sealers have better penetration capacity in dentinal tubules and antimicrobial activity when compared to AH Plus® sealer. This SRM was recorded in the Open Science Framework database and followed the guidelines of the PRISMA 2020. Five databases were searched by two independent reviewers. Only in vitro studies that evaluated the effects of bioceramic sealers on dentinal tubule penetration and antimicrobial activity outcomes compared to AH Plus® sealer were included. Meta-analysis was conducted using R software, using the effect measure of the standardized mean difference (SMD) and inverse variance method. A modified Joanna Briggs Institute's Checklist was used for the risk of bias assessment. A total of 1486 studies were identified, and only 54 studies that fulfilled our eligibility criteria were included in this review. There was no statistical difference between the sealers evaluated for dentinal tubule penetration, in the thirds evaluated: coronal SMD 0.58 [0.14; 1.31], p = 0.12; middle SMD 0.07 [0.54; 0.39], p = 0.75; and apical SMD 0.08 [0.73; 0.56], p = 0.80. Both sealers demonstrated similar antimicrobial action (SMD [3.42; 5.32], p = 0.67 and SMD 0.67 [1.89; 0.55], p = 0.28). The studies presented a low risk of bias. Based on the in vitro studies included and according to the limitations of the present review, the data suggest that bioceramic and AH Plus® sealers present similar penetration capacity in dentinal tubules and antimicrobial effect, making them suitable materials to be considered in clinical practice.

Comparison of the dentin tubule penetration of AH Plus, WellRoot ST, and MTA BioSeal after obturation, retreatment, and re-shaping of the root canals

It was aimed to compare the dentine tubule penetration of AH Plus, MTA Bioseal, and WellRoot ST after filling, retreating, and reshaping the root canals by using a novel microscopic method. Seventy-five mandibular incisors with single root canals were shaped with Protaper Next system (PTN; X2-25/0.06) The teeth were obturated with AH Plus labeled with Rhodamin B and MTA Bioseal or WellRoot ST sealer which were labeled with Fluo-3. Then the root canal fillings were removed with Protaper Universal Retreatment files. At the last stage, the teeth were reshaped with PTN (X3-30/0.07). The samples were transversally sectioned and examined using a Cytation 5 reader and Gen5 software regarding the mean and the maximum depth of sealer penetration. No significant difference was observed between the groups, except for the 6 mm level after reshaping the root canals (p < .05). It is not possible to completely remove the sealer remnants from the dentin walls even after reshaping the root canals. RESEARCH HIGHLIGHTS: Even after reshaping the root canals in the retreatment procedure, it is not possible to completely remove the filling residues of the epoxy-resin-based, calcium-silicate-based and MTA-based endodontic pastes from the dentin walls.

Efficacy of various activation techniques on tubule penetration of resin-based and bioceramic root canal sealers: An in vitro confocal microscopy study

To compare the penetration of Ah Plus and MTA Fillapex after irrigation activation with sonic, passive ultrasonic, SWEEPS and XP-Endo Finisher using confocal microscopy. Instrumented root canals of 160 mandibular premolar teeth were allocated randomly to four groups (n = 40/group) and eight subgroups according to the activation techniques and canal sealers (n = 20/subgroup). After the obturation, three sections at 1-2, 5-6 and 9-10 mm levels from the apex were examined. Penetration area and maximum penetration depth values were represented as mean and standard deviation, and results below 0.05 were considered statistically significant. For penetration area and maximum penetration depth, the statistical difference was found in terms of material, device and region (Maximum penetration depth: p = 0.006, p < 0.001, p < 0.001; Penetration area: p = 0.004, p < 0.001, p < 0.001). SWEEPS was found to be relatively higher than other groups. Sealers presented similar results when evaluated independently of the region. The use of SWEEPS for irrigation activation is promising in terms of tubule penetration.

Analysis of porosity, sealer dissolution and apical extrusion of endodontic sealers: A micro computed tomography study

Aim

The aim of the study was to determine the porosity, dissolution and apical extrusion of AH Plus, MTA Fillapex and EndoSequence BC sealer after immersion in phosphate buffered saline (PBS) using microcomputed tomography (micro-CT).

Methodology

Forty-eight single-rooted teeth were selected. Gutta percha and one of the aforementioned root canal sealers was used for obturation using continuous wave technique. The specimens were scanned after obturation and after seven days of immersion in PBS, by using micro-computed tomography. Porosity, sealer dissolution and apical extrusion were calculated. Statistical analysis was done by using paired t-test, post hoc tukey test and Fischer exact test.

Results

Significantly higher percentage of porosity and dissolution of sealer in the apical 4 mm was found for MTA Fillapex and EndoSequence BC sealer than for AH Plus. The incidence of apical extrusion was significantly more in MTA Fillapex (56.25%), followed by EndoSequence BC (31.25%) and AH Plus (0%).

Conclusions

None of the three root canal sealers exhibited perfect three-dimensional obturation. The sealers manifested porosity, dissolution and apical extrusion to varying degrees both after obturation and after storage in PBS for 7 days.

Evaluation of interfacial adaptation and penetration of bioceramic-based sealers in oval root canals: A confocal laser scanning microscope study

To assess the interfacial adaptation and penetration depth of three different bioceramic-based sealers (CeraSeal, EndoSeal MTA, Nishika Canal Sealer BG) compared to an epoxy resin-based sealer (AH Plus) in oval root canals. Fourty extracted single-rooted mandibular premolar with oval canal were prepared and randomly allocated according to the obturation into; CeraSeal, EndoSeal MTA, Nishika Canal Sealer BG and AH Plus. The roots were sectioned at 3, 6 and 9 mm from the apex. The sealer adaptation and the penetration depth were evaluated under confocal laser scanning microscope. One-way ANOVA and Repeated measure ANOVA were used to statistically analyze the data. Nishika Canal Sealer BG showed significantly higher sealer adaptation than EndoSeal MTA (P < .001) at apical and middle thirds. Meanwhile, AH Plus showed significantly higher sealer adaptation than EndoSeal MTA (P = 0.011) at middle third. For sealer penetration, Nishika Canal Sealer BG showed the longest sealer penetration that was significant compared to AH Plus (P < .001) and EndoSeal MTA (P < .001) whereas CeraSeal was significantly higher than EndoSeal MTA (P = 0.029) at coronal third. For AH Plus, there was a significant less sealer penetration at coronal third compared to apical and middle thirds (P < .05). Whereas for EndoSeal MTA, the coronal third has significant less penetration compared to the middle third (P = 0.032). Endoseal has the lowest adaptation and penetration depth. Nishika Canal Sealer BG has better adaptation and penetration depth using single cone obturation technique in oval canal. RESEARCH HIGHLIGHTS: All the tested root canal sealers have some percentage of gaps and vary in their penetration capability into dentinal tubules. Nishika Canal Sealer BG has significantly better sealer adaptation to root dentinal walls than that of EndoSeal MTA at the apical and middle third but not significantly different from other type of sealers used. Nishika Canal Sealer BG has significantly better penetration depth than AH Plus and EndoSeal MTA at the coronal third of radicular dentin.

Analysis of physicochemical properties of endodontic sealers containing rhodamine B

The use of fluorescent dyes in microscopy studies is frequent. Therefore, it is important to investigate whether these compounds may alter the physicochemical properties of materials in which they are incorporated to avoid methodological biases. This study evaluated the physicochemical properties of two endodontic sealers containing dry or diluted rhodamine B. Six groups were evaluated: AH Plus and MTA Fillapex in their original composition and mixed with 0.1% dry or diluted rhodamine. Push-out test was applied to assess the bond strength to root dentin. ANSI-ADA No. 57 and ISO No. 6876:2012 specifications were followed to evaluate flowability, setting time, and solubility of the sealers. pH changes were assessed after 24 h, 7, and 30 days. Intergroup comparisons were analyzed by ANOVA complemented by Tukey's post-hoc test; comparisons among periods were analyzed by Wilcoxon and Friedman tests. The incorporation of dry rhodamine decreased the bond strength and prolonged the setting time of AH Plus. The incorporation of diluted rhodamine decreased the setting time and increased the flowability of MTA Fillapex. Diluted rhodamine promoted pH reduction of AH Plus after 24 h and dry rhodamine after 7 days. Rhodamine incorporation promoted pH reduction after 30 days for MTA Fillapex. Solubility was not affected. In conclusion, the incorporation of diluted rhodamine changed the properties of MTA Fillapex, and the incorporation of dry rhodamine changed the properties of AH Plus. Previous dilution of rhodamine did not severely compromise the physicochemical properties of AH Plus and may be suggested to assess its penetrability.

Interfacial characteristics of BIOfactor MTA and Biodentine with dentin

The objective of this study was to characterize the interface between dentin and MTA-Angelus (Angelus, Londrina, Brasil), Biodentine (Septodont, France) and BIOfactor MTA (Imicryl, Konya, Turkey) using scanning electron microscopy (SEM), energy disperse X-ray spectroscopy (SEM-EDS) and confocal laser scanning microscopy (CLSM). Fifteen dentin segments were obtained from previously extracted single-rooted human teeth. Canal lumens were instrumented with diamond burs and then randomly filled with MTA-Angelus, Biodentine or BIOfactor MTA and placed in distilled water or Hanks' Balanced Salt Solution (HBSS) for 28-days. The samples were examined with SEM and the thickness of the interfacial layer measured. SEM-EDS analysis was performed to determine principal elemental composition of the material, dentin, and interfacial area. The marginal adaptation of cements to dentin was assessed by confocal microscopy and the percentage of material penetration was calculated. An interfacial layer was evident in approximately 70% of SEM images in both MTA-Angelus and BIOfactor samples. The thickness of interfacial layer was significantly higher in HBSS than in distilled water for all groups. MTA Angelus resulted in the thickest interfacial layer in distilled water while Biodentine had the thickest interfacial layer in HBSS. Calcium levels within the BIOfactor MTA-dentin interface were higher than both dentin and cement. Dentin penetration was higher in BIOfactor MTA and silicon was evident in all material-dentin interfaces. All calcium silicate-based materials promoted the formation of an interfacial layer. BIOfactor MTA exhibited promising characteristics with its good marginal adaptation even though it presented a moderately thick interfacial layer. RESEARCH HIGHLIGHTS: A distinguishable interfacial layer was observed in most of the samples within the BIOfactor MTA, MTA-Angelus and Biodentine groups. The elemental constitution of the interfacial layer was different from that of the calcium silicate based materials.

The effects of different root canal irrigation protocols and artificial aging procedures on the bond strength between dentin and hybrid ceramic posts

The purpose of this study is to investigate the effects of different root canal irrigation protocols applied to the dentin and artificial aging procedures on the micro pushout bond strength (mPBS) between dentin and hybrid ceramic posts. Seventy-five single-rooted mandibular premolar teeth were divided into 5 groups (Gr1-5). 50 of the teeth were used for the mPBS tests (n = 10), whereas 25 were used for the smear layer examinations (n = 5). Post space were prepared and irrigated with different irrigation-protocols in each group. (Gr1:[SS], Gr2:[NaOCl] + SS, Gr3:[EDTA] + NaOCl + SS, Gr4:[MA] + NaOCl + SS, Gr5:[Ch] + NaOCl + SS). Post and core pattern were fabricated with pattern resin and a fiber post, after scanning, the posts were milled with Vita Enamic resin ceramic block, and cemented. After 7 days the roots were sliced at thicknesses of 1 mm; half of them were subjected to mPBS test, while the other half were tested after undergoing mechanical cycling for artificial aging. For data analysis, the Shapiro-Wilk test was utilized to test normal distributions, 3-way analysis of variance was used to compare mPBS, and Tukey's HSD test was conducted for multiple comparisons. SEM analysis was performed for examination of failure modes and smear layer removal. Different root canal irrigation protocols affected mPBS significantly. While Gr4 had the highest mPBS, Gr1 had the lowest. Regarding to different zones, the highest mPBS was in coronal zone, and the lowest one was in the apical zone. The aging procedure also led to a statistically-significant decrease in mPBS. Most frequent failure modes were cohesive failure in dentin and mixed failure. Irrigation with 7%MA (Gr4) showed better performance than 17% EDTA (Gr3) in smear layer removal, especially at the apical zone of the tooth. This is critical for the success of root canal treatment and increased the mPBS to a higher extent in all zones of the tooth.

Laboratory study of tissue repair of resin-based endodontic sealers in critical surgical defects

Filling materials should be restricted to the root canal space. However, sometimes it is impossible to control the apical extrusion, in this case, the fate of the filling material and the result of the treatment will depend on its physicochemical properties and biocompatibility.

Hydration Characterization of Two Generations of MTA-Based Root Canal Sealers

Since the setting characterization of a root canal sealer has an impact on its biological behavior of final obturation, this study evaluated the setting characterization of mineral trioxide aggregate MTA-Fillapex versus MTA-Bioseal compared with epoxy resin (Adseal) root canal sealers. Freshly mixed sealer was inserted into the mold (n = 10). The initial and final setting times were evaluated using a Vicat needle and were then statistically analyzed by one-way ANOVA at p < 0.05. The raw pastes and the stages of the setting reaction were analyzed using Fourier Transform Infrared (FTIR) Spectroscopy. The phase compositions were evaluated using X-ray diffraction (XRD). A significant and fast setting time was recorded by Adseal (4.7 ± 0.46 h) followed by MTA-Bioseal (11.4 ± 1.34 h) at p < 0.001. The MTA-Fillapex did not set completely in three months. The FTIR and XRD of both MTA-Bioseal and Adseal detected bands of the polymerized phases, while those of MTA-Fillapex detected partial polymerization with a low percentage of polymerized silica. MTA-Bioseal and Adseal met the ISO standards for setting times. However, MTA-Fillapex did not fulfill the ideal requirement for the sealer. Although the raw pastes of both MTA-sealers had nearly similar compositions, they behaved differently during the hydration reaction. MTA-Bioseal set completely, while MTA-Fillapex was not completely set.

Comparison of Dentinal Tubule Penetration between a Calcium Silicate-Based Sealer with Ultrasonic Activation and an Epoxy Resin-Based Sealer: A Study Using Confocal Laser Scanning Microscopy

OBJECTIVE

 The aim of this study was to compare the degree of dentinal penetration between an epoxy resin-based sealer applied by using two different filling methods and an ultrasonically activated calcium silicate-based sealer via confocal laser scanning microscopy (CLSM).

MATERIALS AND METHODS

 Forty-five extracted permanent maxillary premolars with type II canals (Vertucci's classification) were subjected to the experiment. The root canals were instrumented and distributed randomly into the following three groups: AH Plus + continuous wave technique (AHC group); AH Plus + single cone technique (AHS group); and Endoseal MTA + single cone technique with ultrasonic activation (EMS) group. Each sealer was labeled with rhodamine B dye to allow visualization under CLSM. The sealer penetration depth in each sample was observed at 2 mm and 5 mm from the apex by using CLSM. The data were statistically analyzed by using analysis of variance or Kruskal-Wallis H test according to normality of variable (α = 0.05).

RESULTS

 In all groups, the maximum sealer penetration depth, mean fluorescence intensity, and sum fluorescence intensity values were higher at the 5-mm level than at the 2-mm level. At the 5-mm level, the EMS group showed the lowest value (p = 0.02). At the 2-mm level, there were no statistically significant differences among any of the groups. The AHC group showed higher values than the other groups, but there was no statistically significant difference in the apical area where access of instruments was difficult.

CONCLUSION

 The AHC group showed the highest dentinal tubule penetration, but had questionable filing efficacy in the apical area, which is of particular importance for the success of root canal treatment. Therefore, in areas such as the apical 2 mm of premolars with type II canals, which are difficult to access by using instruments such as heat carriers, other appropriate approaches may be required accordingly.

Physicochemical Properties of Two Generations of MTA-Based Root Canal Sealers

This study evaluated the physicochemical properties and the effect of solubility on the surface morphology and composition of the root canal sealers MTA-Bioseal, MTA-Fillapex, and Adseal. Discs (n = 10) of freshly mixed sealer were prepared and then analyzed by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX). The discs were immersed for 1, 7, 14, and 28 days in deionized water. The solubility %; pH change of the solution; and released calcium, phosphate, and silicon were measured for each period. The flowability and film thickness were also evaluated. Changes in the surface morphology and composition after 28 days of immersion were evaluated by SEM/EDX. The data were statistically analyzed by one-way ANOVA at p < 0.05. The FTIR and EDX results revealed similar compositions of MTA-Bioseal and MTA-Fillapex, but with different concentrations. The two MTA-based sealers had higher solution alkalinity (pH > 10) than Adseal (pH ≈ 8.5). MTA-Fillapex exhibited the highest solubility % and the largest calcium and silicon ion release. MTA-Bioseal had the highest phosphate ion release. After 28 days, the sealer surfaces showed large micropores, with larger pores in MTA-Fillapex. Adseal had an intermediate flowability but exhibited the greatest film thickness. Finally, the highest solubility and largest amount of silicon release was exhibited by MTA-Fillapex, which might predispose it to the development of large micropores, compromising the apical seal of obturation.

An ultrasonic-based experimental model to evaluate the setting time of endodontic sealers

AIM

To evaluate an ultrasonic-based experimental model (US), to assess the setting time of AH Plus^® , Bio-C Sealer^® and MTA Fillapex^® , and compare the results obtained with ANSI/ADA specifications (2012).

METHODS

To determine the setting time according to the ANSI/ADA specification, moulds measuring 10 mm (diameter) × 2 mm (thickness) were used, and for the US tests a transducer (1 MHz) and an oscilloscope were used. Fourier-transform infrared spectroscopy (FTIR) was used to evaluate the changes on chemical structure at the different setting times found by the US and ANSI/ADA methods. After checking the normal distribution, setting time data were analysed using unilateral analysis of variance with Tukey-HSD post-test to compare the methods.

RESULTS

AH Plus^® and Bio-C Sealer^® had longer mean setting time values for the US method than for the ANSI/ADA (p < .05), whilst for MTA Fillapex^® no significant difference was found between the methods (p < .05). FTIR spectra demonstrated that at the setting time determined by the US method, AH Plus^® and Bio-C Sealer^® were in a more advanced stage of polymerization than at the ANSI/ADA, whilst there was no significant difference for MTA Fillapex^® .

CONCLUSIONS

The use of US was effective for setting time determination and measured longer values than ANSI/ADA specification for AH Plus^® and Bio-C Sealer^® , identifying the entire (and not only superficial) setting of the endodontic sealers.

A matched irrigation and obturation strategy for root canal therapy

In root canal therapy, irrigating solutions are employed to eliminate the bacterial load and also prepare dentin for sealer interaction. The aim of this research was to assess how irrigating solutions employed on their own or in sequence affected the tooth structure. The best way to prepare the tooth for obturation using hydraulic calcium silicate cement (HCSC) sealers and gutta-percha, thus guiding clinicians on a matched irrigation-obturation strategy for optimized root canal treatment was investigated. The effect of irrigating solutions on dentine was investigated by assessing changes in dentin microhardness, ultrastructure and mineral content, organic/inorganic matter, surface roughness and Young’s modulus. The interaction of four root canal sealers with the dentin was analysed by assessing the changes in microhardness of the dentin after sealer placement and also the sealer to dentin interface by scanning electron and confocal laser microscopy. The irrigating solutions damaged the dentin irreversibly both when used on their own and in combination. The best sequence involved sodium hypochlorite followed by chelator and a final rinse with sodium hypochlorite and obturation using HCSC sealers that enabled the restoration of dentin properties. The HCSC sealers did not rely on chelator irrigating solutions for a good material adaptation to dentin.

Evaluation of the amount of remained sealer in the dentinal tubules following re-treatment with and without solvent

Background:

The effect of solvent and sealer type (BioRoot RCS [BRRCS], mineral trioxide aggregate [MTA] Fillapex, and AH26) on the root canal residues was evaluated by confocal laser scanning microscopy (CLSM).

Materials and Methods:

Distal root canals of 60 mandibular molars prepared up to ProTaper-F4 were filled using one of the sealers labeled with 0.1% rhodamine-B (n = 20 per sealer). Samples were divided into two according to reprocessing methods as follows: ProTaper Universal Reprocessing System (PTUR) or solvent plus PTUR. Samples were sectioned at 2–5 and 8 mm from the apex and the samples were observed under CLSM. Penetration depth, percent penetration depth, and percent penetration into canal walls were evaluated. Statistical analysis was performed using the repeated measures of the two-way ANOVA and Bonferroni post hoc test at P = 0.05.

Results:

The highest penetration depth was measured in BRRCS in all root canal thirds with or without chloroform addition. Percentage of penetration depth values of MTA Fillapex and BRRCS was statistically similar and higher than AH26 in all sections, except the apical section re-treated with the addition of chloroform.

Conclusion:

None of the sealers were completely removed. The type of sealant and the use of chloroform changed the amount of sealant remaining in the root canal system.

Solubility of bioceramic- and epoxy resin-based root canal sealers: A systematic review and meta-analysis

This systematic review and meta-analysis evaluated whether epoxy resin-based root canal sealers present an increased solubility than calcium silicate-based root canal sealers. A systematic search was performed in the following databases: PubMed, Science Direct, Scopus, Web of Science and Open Grey. The inclusion criteria consisted of in vitro studies that compared the solubility of epoxy resin-based and calcium silicate-based sealers. The quality assessment and data extraction of the selected articles were performed. The meta-analysis of the pooled data and the subgroups according to the root thirds were carried out using the RevMan software (P < 0.05). After the duplicate removal and eligibility criteria assessment, a total of 22 studies were included all of them were considered as having a low risk of bias. The meta-analysis demonstrated overall lower solubility of AH Plus. AH Plus presented lower solubility than Bio-C Sealer, BioRoot RCS, MTA Fillapex, Sealer Plus and Total Fill BC Sealer.

Effect of Ultrasonic Activation of Endodontic Sealers on Intratubular Penetration and Bond Strength to Root Dentin

INTRODUCTION

This study aimed to evaluate the effect of ultrasonic activation (UA) of endodontic sealers on dentin tubule penetration and the bond strength to root dentin.

METHOD

One hundred single-rooted teeth were prepared with 40.06 nickel-titanium instruments and divided into 2 groups: with or without UA. Three resin-based sealers (MTA Fillapex [Angelus Dental Solutions, Londrina, PR, Brazil], Sealer Plus [MK Life Medical and Dental Products, Porto Alegre, RS, Brazil], and AH Plus [Dentsply, DeTrey GmbH, Konstanz, Germany]; n = 20) and 2 calcium silicate-based sealers (Sealer Plus BC [MK Life Medical and Dental Products] and EndoSequence BC [Brasseler, Savannah, GA], n = 20) were used and subdivided (n = 10) according to the protocols. Fluo-3 (Thermo Fisher Scientific, Waltham, MA) and rhodamine B dyes were added to the calcium silicate- and resin-based sealers, respectively. In the UA groups, the activation was performed for 40 seconds followed by lateral compaction. Samples were transversely sectioned to evaluate the dentin tubule penetration and the bond strength to root dentin. The penetration data were analyzed with the Student t test, 1-factor analysis of variance, and Bonferroni tests. Bond strength was evaluated using the Student t test, Kruskal-Wallis, and Dunn post hoc test.

RESULTS

Resin-based sealers showed the highest tubule penetration without UA (P < .05). UA significantly enhanced MTA Fillapex and Endosequence BC dentin tubule penetration (P < .05). AH Plus and Sealer Plus BC improved their bond strength to root dentin after UA (P < .05). AH Plus/UA, Sealer Plus/UA, and Sealer Plus BC/UA presented the highest bond strength values (P < .05). Adhesive failures were predominant in all groups regardless of the use of ultrasound.

CONCLUSIONS

UA interferes with tubule penetration and the bond strength to root dentin of resin- and calcium silicate-based sealers.

Correlation between Bond Strength to Dentin and Sealers Penetration by Push-Out Test and CLSM Analysis

This study correlated the bond strength (BS) and dentin penetration of different sealers by push-out test and Confocal Laser Scanning Microscopy (CLSM) analysis. Forty-five root canals were prepared according to the crown-down technique and filled with gutta-percha associated to the following sealers (n=15): Endofill, AH Plus and MTA Fillapex. Five canals of each group were filled with the sealers added with 0.1% Rhodamine B dye. Next, the specimens were transversely sectioned and submitted to the push-out test (n=10) and CLSM analysis (n=5). The BS data showed the following means (MPa) and standard deviation: AH Plus (4.17±1.86); MTA Fillapex (3.13±1.96) and Endofill (2.10±1.03). Statistical analysis (two-way ANOVA, α=0.05) showed significant difference among sealers (p<0.001) and root canal thirds (p<0.001). The BS results of Endofill and MTA Fillapex were statistically similar (p>0.05), however, they were statistically different from AH Plus (p<0.001). The regional analysis of BS showed similarity between middle and apical thirds (p>0.05), and both were different from coronal portion (p<0.001). CLSM analysis verified tags formation in all groups and higher penetration of the specimens filled with AH Plus (p<0.05). The Kendall test (correlation between BS to dentin and sealer penetration into dentinal tubules) and the Pearson test (between failures pattern and sealer penetration into dentinal tubules) did not show correlation between the variables evaluated for all the tested sealers (p>0.05). AH Plus group had higher BS to dentin, and deeper tags formation than the other sealers. There was no significant correlation between BS and intratubular penetration of the tested sealers.

Comparative effects of final canal irrigation with chitosan and EDTA

Chitosan is a natural, biocompatible chelating substance with potential for dental use. This study compared the effects of final canal irrigation with chitosan and EDTA on dentin microhardness, sealer dentin tubules penetration capacity, and push-out strength.

Effect of peracetic acid used as single irrigant on the smear layer, adhesion, and penetrability of AH Plus

The aim of this study was to evaluate the effect of peracetic acid (PAA) as a single irrigant on the smear layer, on the intraradicular dentinal bond strength, and on the penetrability of an epoxy-based resin sealer into the dentinal tubules. A total of 120 roots were distributed into 4 groups according to the irrigant used in root canal preparation: 1% PAA (PAA); 2.5% NaOCl followed by final irrigation with 17% EDTA and 2.5% NaOCl (NaOCl-EDTA-NaOCl); 2.5% NaOCl (NaOCl); and saline solution (SS). The smear layer was evaluated using scanning electron microscopy. The bond strength of an epoxy-based resin sealer (AH Plus) to root dentin was evaluated by the push-out test and penetrability of the sealer into dentinal tubules was observed by confocal laser microscopy. The results were analyzed by the Kruskal-Wallis and the Dunn post-test (α = 0.05). The use of 1% PAA as single root canal irrigant provided smear layer removal and improved the penetrability and bond strength of AH Plus to root dentin in a manner similar to that of the NaOCl-EDTA-NaOCl group (p > 0.05). The NaOCl and SS groups had higher values of smear layer and lower values of sealer penetrability and dentin bond strength than the PAA and NaOCl-EDTA-NaOCl groups (p < 0.05). Thus, 1% PAA has the potential to be used as a single irrigant in root canals.

Solubility, Porosity, Dimensional and Volumetric Change of Endodontic Sealers

The aim of this study was to evaluate physical properties of endodontic sealers (AH Plus, MTA Fillapex and Endofill), by conventional and micro-CT tests. Dimensional stability was evaluated after immersion of materials in distilled water for 30 days. Solubility and volumetric change were evaluated after 7 and 30 days of immersion in distilled water. Solubility was evaluated by means of mass loss and volumetric change was assessed by micro-CT. Porosity was evaluated under a microscope after 7 days of immersion in distilled water, and by using micro-CT after setting and immersion in distilled water for 7 and 30 days. Statistical analysis was performed by ANOVA and Tukey's test with 5% significance level. MTA Fillapex presented the highest solubility (p<0.05), showing values above the ISO/ADA recommendations. MTA Fillapex presented higher volumetric and dimensional changes, followed by Endofill and AH Plus (p<0.05). Dimensional stability of the MTA Fillapex and AH Plus did not follow ISO/ADA standards. The highest total porosity was observed for MTA Fillapex (p<0.05). Endofill had higher total porosity than AH Plus according to microscope evaluation (p<0,05), and both sealers were similar in micro-CT assessment (p>0,05). In conclusion, MTA Fillapex presented higher solubility, dimensional and volumetric change besides porosity compared to the other evaluated sealers. The assessed physical properties of sealers are related, and the different tests provided complementary data. Micro-CT is a valuable method for assessment of physical properties of endodontic materials.

Do in vitro solubility studies on endodontic sealers demonstrate a high level of evidence? A systematic review

OBJECTIVE

To systematically review the quality of evidence of available in vitro solubility studies on endodontic sealers according to prespecified evidence criteria.

MATERIAL AND METHODS

This systematic review was based on the PRISMA guidelines and the AMSTAR measurement tool. A systematic duplicate search of the literature on endodontic sealer solubility studies was conducted in PubMed and Embase databases (until 18 October 2017). Mapping terms to subject headings and free text terms were used and combined with hand searching before exclusion of duplicates. Studies specifically dealing with endodontic sealer solubility were selected. The evidence level was graded (low, medium or high) independently by two investigators following systematic data extraction in pilot forms, which was based on prespecified evidence criteria and the modified CONSORT checklist for in vitro studies on dental materials.

RESULTS

The search retrieved 1053 articles, from which 88 were assessed in full. From the 63 articles retained in the final analysis, 11 were classified as having moderate and 52 as low quality of evidence (0 high). The studies graded as low had low sample size (n < 10) and/or insufficient details to allow replicability. Most of the studies did not conform to the modified CONSORT checklist and did not include parameters considered relevant in the prespecified criteria.

CONCLUSIONS

Existing in vitro studies on the solubility of endodontic sealers do not demonstrate a high quality of evidence. Most of these studies do not present systematic reporting nor employ relevant parameters prespecified in our evidence criteria.

Influence of the EndoActivator Irrigation System on Dentinal Tubule Penetration of a Novel Tricalcium Silicate-Based Sealer

This study compared the effects of a conventional endodontic needle with an agitation system on a novel tricalcium silicate-based sealer (NTS) in terms of dentinal tubule penetration and interfacial adaptation to a root canal. Fifty single-rooted, recently-extracted human maxillary central incisors were randomly distributed into two homogeneous groups characterized by two different final cleansing systems: Conventional endodontic needle, or EndoActivator^®. After instrumentation, all the teeth were filled with the gutta-percha single cone technique in conjunction with the novel tricalcium silicate-based sealer. Teeth were horizontally sectioned at 1 and 5 mm from the apex and were observed under a confocal laser scanning microscope (CLSM) at five magnifications. The maximum, mean, and the circumferential percentage of the sealer penetration inside the tubules were measured. Moreover, the gap width was evaluated using Image J software (National Institutes of Health, Bethesda, MD). EndoActivator^® did not result in a significantly higher circumferential percentage of sealer penetration than conventional irrigation (p > 0.05). However, the gap width was significantly lower with EndoActivator^®, compared to conventional needles at both 1 mm (p = 0.035) and 5 mm (p = 0.038). The EndoActivator^® irrigation system did not significantly improve the NTS penetration, as compared to the conventional endodontic needle irrigation. Activation of the irrigation reduced the gap width significantly.

Bond Strength of Experimental Root Canal Sealers Based on MTA and Butyl Ethylene Glycol Disalicylate

Abstract This study investigated the bond strength of two experimental root canal sealers based on MTA and butyl ethylene glycol disalicylate: MTAe and MTAe-HA. The reference materials used for comparison were AH Plus and MTA Fillapex. Twenty human upper incisors were selected and one 1 mm slice was obtained from the cervical third of each root. On the coronal surface of each slice, four 0.9 mm wide holes were drilled through the dentine. Standardized irrigation was performed and holes were filled with one of the four tested sealers: AH Plus, MTA Fillapex, MTAe, and MTAe-HA. The filled slices were stored in a PBS solution (pH 7.2) for 7 days at 37 °C. A push-out assessment was performed with a 0.7 mm plunger tip. Load was applied at a crosshead speed of 0.5 mm/min until sealer displacement. The results were expressed in MPa. The Kruskal-Wallis test was applied to assess the effect of each sealer on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. Significant differences among medians values obtained by materials were observed (p<0.001). AH Plus displayed the highest value of bond strength (p<0.001). In contrast, MTA Fillapex presented the lowest bond strength among all tested sealers (p<0.001). Experimental sealers showed intermediary bond strength values, with no statistical differences between them (p>0.05). In conclusion, experimental root canal sealers presented suitable bond strength outcomes when compared to MTA Fillapex.

In vitro study of dentinal tubule penetration and filling quality of bioceramic sealer

This study aimed to evaluate the dentinal tubule penetration and filling quality of a bioceramic sealer (iRoot SP). Forty-two roots of extracted adult lower incisors were selected. After instrumentation with Protaper Universal to F3, 40 roots were chosen and randomly divided into 4 groups, as follows: iRoot SP single cone group, iRoot SP warm vertical group, AH Plus single cone group, and AH Plus warm vertical group. Before root canal filling, sealers were mixed with Rhodamine B dye for visualization under confocal laser scanning microscope. All samples were sectioned at 2, 4, and 6 mm to apex. Then, the percentages of void areas, gap regions, and segments of sealer that penetrated into dentinal tubules in each section were calculated. Non-parametric test was used for statistical analysis (α = 0.05). We found that filling techniques and types of sealer had no statistically significant effects on the occurrence of voids and gaps. The segments of iRoot SP penetrated into dentinal tubules were statistically more than that of AH Plus in both single cone and warm vertical techniques at 2 mm to apex (P < 0.05). Regardless of the filling technique used, iRoot SP can achieve comparable filling quality and better dentinal tubules penetration than AH Plus. Considering the good bioactivity of iRoot SP, it may help improve the seal of root canal system.

Effect of photodynamic therapy and non-thermal plasma on root canal filling: analysis of adhesion and sealer penetration

Objective

The aim of this study was to evaluate the effect of photodynamic therapy (PDT) and non-thermal plasma (NTP) on adhesion and sealer penetration in root canals.

Material and Methods

Sixty single-rooted premolars were used. The teeth were prepared using a crown-down technique. NaOCl and EDTA were used for irrigation and smear layer removal, respectively. The root canals were divided into three groups: control, PDT, and NTP. After treatments, the roots were filled using gutta-percha and either AH Plus (AHP) or MTA Fillapex (MTAF) sealers. Samples were sectioned at 4, 8, and 12 mm from the apex (1-mm slices)and analyzed by the push-out bond strength test (adhesion) and confocal laser scanning microscopy (sealer penetration). Data were statistically evaluated using Kruskal-Wallis, Dunn’s, and Spearman’s tests.

Results

Regarding AHP, bond strength was similar in the NTP group and in the control group, but significantly lower in the PDT group. As to MTAF, both therapies showed lower values than the control group. In the confocal analysis of AHP, maximum and mean penetration, and penetrated area were statistically higher in the control group than in the PDT and NTP groups. Penetrated perimeter was similar among groups. Regarding MTAF, all parameters yielded better results in the NTP than in the control group. The PDT and control groups showed similar results except for penetrated area.

Conclusion

PDT and plasma therapy affected the adhesion and sealer penetration of root canals filled with AH Plus and MTA Fillapex and there is no positive correlation between adhesion and sealer penetration.

Composition and physicochemical properties of calcium silicate based sealers: A review article

Background

Recently a new generation of endodontic sealers has been developed based on calcium silicate as MTA Fillapex, Endoseal MTA, Total Fill BC Sealer, EndoSequence BC Sealer, iRoot SP, Endo CPM sealer, MTA-Angelus and ProRoot Endo Sealer. A review of literature was conducted to discuss the composition, physicochemical properties, and clinical perspectives of calcium silicate based sealers.

Material and Methods

A literature search was conducted in PubMed and web of knowledge databases with appropriate MeSh terms and keywords. A total of 71 studies were reviewed for data extraction.

Results and Conclusions

Calcium silicate based sealers showed suitable physical properties to be used as an endodontic sealer. However, its high solubility remains an important issue. They show good performance regarding calcium ion release, film thickness, and fowability. More researches are required about features of calcium silicate based sealers before recommending them for clinical applications.

Key words:Calcium silicate, root canal filling materials, composition, physical properties.

Capacidade de selamento e penetração intratubular do MTA Fillapex e do AH Plus em dentes humanos

Resumo Introdução O MTA é um importante material de uso na odontologia, com boas propriedades biológicas. As respostas experimentais aos cimentos endodônticos que utilizam este composto no selamento e preenchimento do sistema de canais radiculares, aliados a uma boa instrumentação e limpeza, podem ser importantes no processo de reparo periapical. Objetivo Avaliar in vitro a profundidade de penetração de dois diferentes cimentos endodônticos nos túbulos dentinários e a infiltração bacteriana em obturações com os cimentos AH Plus e MTA Fillapex. Material e método 34 pré-molares monorradiculados humanos foram selecionados, suas coroas removidas e suas raízes padronizadas em 16 mm, a seguir foram, então, divididos aleatoriamente em dois grupos de 15 espécimes e instrumentados com o sistema rotatório Pro Taper. Um grupo foi obturado com o cimento AH Plus (Grupo AH) e outro com MTA Fillapex (Grupo FI). Nestes grupos, avaliaram-se a infiltração coronária de bactérias para Enterococcus Faecalis e a profundidade de penetração nos túbulos dentinários. Para a aferição da infiltração bacteriana, usou-se o teste exato de Fisher; para a penetração intratubular, usou-se o teste-t. Resultado Para a infiltração bacteriana, considerando o número de amostras infiltradas para AH e MTA Fillapex, houve diferença estatística significativa (p=0,0341). Na avaliação da penetração intratubular, a diferença entre os dois grupos de cimentos foi considerada estatisticamente significativa (p=0,0006). Conclusão Ambos os cimentos apresentaram infiltração bacteriana, sendo que o MTA Fillapex teve pior desempenho. A capacidade de penetração nos túbulos dentinários do AH Plus foi significativamente maior que a do MTA Fillapex.

Cytocompatibility of calcium silicate-based sealers in a three-dimensional cell culture model

OBJECTIVES

The aim of the present study was to evaluate cytotoxic effects and cytokine production of calcium silicate-based sealers (EndoSeal, EndoSequence BC Sealer, and MTA Fillapex) using an in vitro root canal filling model and three-dimensional (3D) cell culture. AH Plus as a reference was compared to contemporary calcium silicate cements regarding cell viability and cytokine production.

MATERIAL AND METHODS

Root canals of 30 human maxillary incisors were prepared using a single-file reciprocating technique. The samples were randomly distributed and canals filled with either AH Plus, EndoSeal, EndoSequence BC Sealer, and MTA Fillapex (n = 6). In the negative control group, the root canal remained unfilled. Sealers were placed into the canals along with a gutta-percha cone placed to working length. Balb/c 3T3 fibroblasts, cultured in a type I collagen 3D scaffold, were exposed to filling material and the respective root apex for 24 h. Cytocompatibility of the materials was evaluated using the methyl-thiazoldiphenyl-tetrazolium (MTT) assay. The production of IL-1β, IL-6, and IL-8 was analyzed using enzyme-linked immunosorbent assay (ELISA). One-way analysis of variance was performed, and when the F-ratios were significant, data were compared by Duncan's multiple-range test. The alpha-type error was set at 0.05.

RESULTS

EndoSeal, Endosequence BC Sealer and AH Plus showed cell viability that was similar to the negative control group (P > 0.05), while MTA Fillapex sealer was cytotoxic (P < 0.05). Varying production of IL-1β, IL-6, and IL-8 was detected in all samples.

CONCLUSIONS

In an in vitro root canal filling model with 3D cell culture, AH Plus, EndoSeal, and EndoSequence BC Sealer were cytocompatible.

CLINICAL RELEVANCE

These results may suggest that AH Plus, EndoSeal and EndoSequence BC Sealer may achieve better biological response when compared to MTA Fillapex.

Dissolution, dislocation and dimensional changes of endodontic sealers after a solubility challenge: a micro-CT approach

AIM

To evaluate, using a novel micro-CT approach, the solubility and dimensional changes of an MTA-based sealer inside the root canal system after a solubility challenge. The MTA-based material (MTA Fillapex) was compared to a gold standard epoxy-based endodontic sealer (AH Plus).

METHODOLOGY

Ten human mandibular premolars with a single canal were divided randomly into two groups (n = 5) according to the sealer used. The canals were instrumented using the Reciproc System (VDW) with a R40 file and filled with R40 gutta-percha cones and one of the sealers. The filled canals were immediately scanned in a micro-CT, and after that, the teeth were immersed in 20 mL phosphate-buffered saline (PBS) at 37 °C for 7 days, when they were removed and rescanned. Final image stacks were registered against the initial stacks and the numerical difference between the initial and final volume of the filling material was obtained. Calculations were performed to identify dimensional changes of the filling material. All image stacks were 3D rendered to disclose areas of dislocation of the filling material inside or outside the root canal. The Shapiro-Wilk's test revealed that data were normally distributed; thus, the Student's t-test was used to detect statistically significant changes, assuming a 5% α-error.

RESULTS

No significant changes were seen for the percentage volume of material lost after the solubility challenge for both AH Plus and MTA Fillapex groups (1.44% and 1.16%, respectively). A significant difference was, however, found for the volume of filling material which revealed dimensional changes after the solubility test (6.68% for MTA Fillapex and 1.09% for AH Plus). In fact, observation of 3D models disclosed that MTA Fillapex was associated with material extrusion through the foramen in all but one sample. In AH Plus filled samples, no material extrusion was detected.

CONCLUSIONS

Although the solubility of both sealers was similar using this novel micro-CT approach, MTA Fillapex was associated with significant dimensional changes related to material extrusion through the apex after PBS storage compared to AH Plus.

Filling Effectiveness and Dentinal Penetration of Endodontic Sealers: A Stereo and Confocal Laser Scanning Microscopy Study

Abstract: The aim of this study was to evaluate the filling effectiveness and dentinal penetration of the sealers AH Plus, Pulp Canal Sealer EWT, Sealapex and MTA Fillapex applied according to the vertical condensation technique using thermoplastic gutta-percha. Forty single-rooted teeth were selected. After chemical-mechanical preparation and root-canal filling, sections of the root (2, 4 and 6 mm from the apex) were obtained and analyzed by stereo microscopy and confocal laser scanning microscopy. Data were tabulated and statistically analyzed. With regard to the assessment of void spaces in the filling material at 2 mm from the apex, the sealers showed similar results, but at 4 and 6 mm from the apex, MTA Fillapex had inferior performance compared to AH Plus (at 4 mm), Pulp Canal Sealer EWT (at 4 and 6 mm) and Sealapex (at 6 mm) (p<0.05). With regard to the penetration into dentinal tubules at 2 mm from the apex, the sealers also showed similar results, but at 4 and 6 mm Pulp Canal Sealer EWT had an inferior performance compared to MTA Fillapex and AH Plus, respectively (p<0.05). All four sealers were found to be similar regarding adaptation of the filling material to the root canal walls, except the MTA Fillapex, which showed failures at 4 and 6 mm from the root apex. With regard to the ability to penetrate into the dentinal tubules, the sealers were found to be equivalent, except for the Pulp Canal Sealer EWT as it had poorer results at 4 and 6 mm compared to MTA Fillapex and AH Plus, respectively.

Porosity and sealing ability of root fillings with gutta-percha and BioRoot RCS or AH Plus sealers. Evaluation by three ex vivo methods

AIM

To investigate the ability of BioRoot RCS, a tricalcium silicate-based root canal sealer and AH Plus to effectively fill the root canals of contralateral teeth using three evaluation methods, and to investigate also the correlation between the methods.

METHODOLOGY

The prepared root canals of ten pairs of contralateral mandibular premolar teeth were filled with gutta-percha and sealer using lateral compaction. The percentage of voids within the root canal was assessed by micro-computed tomography, whilst sealing ability was investigated by fluid transport and leakage of fluorescent microspheres. The interaction of sealer with dentine, and sealer penetration were assessed by confocal microscopy. The void volume, fluid flow, microsphere leakage and sealer interaction with dentine for both materials were compared. Nonparametric (Mann-Whitney) tests were used to compare the % void and fluid transport of the two sealers. Spearman correlation was used to assess the pairwise relationships between the techniques. The level of significance was set to 0.05.

RESULTS

BioRoot RCS exhibited significantly more percentage of voids than AH Plus. There was no difference in fluid flow and microsphere penetration. BioRoot RCS exhibited a different pattern of sealer penetration and interaction with the dentine walls compared to AH Plus. For both materials, the pairwise correlations between the three techniques were close to zero, indicating weak relationships.

CONCLUSIONS

MicroCT analysis revealed a higher void volume for BioRoot RCS. The other techniques did not show a difference between the sealing ability of the sealers. The correlation between the three ex vivo methods of assessment was weak demonstrating their complementarity rather than their concordance.