Volumetric changes in root canal sealers in ex vivo and a novel animal model approach.

AIM: This study aimed to evaluate the volumetric change of root canal sealers through micro-computed tomographic analysis using a novel in vivo model and to compare the results with those obtained using an ex vivo test. METHODOLOGY: Eighteen single-rooted teeth were cut to 5 mm length from the root apex. The root canals were uniformly enlarged and filled with EndoSequence BC Sealer or AH Plus Jet root canal sealers. Samples were stored at 37°C and 95% relative humidity for 24 h and then scanned with a micro-CT device. Twelve samples (n = 6 for each sealer) were implanted in the subcutaneous tissue of Wistar rats, while six samples (n = 3 for each sealer) were immersed in 20 mL of phosphate-buffered saline (PBS) at 37°C at neutral pH. After 7 and 30 days, teeth were removed from subcutaneous tissue or PBS and rescanned. Statistical analysis of volume changes was performed using Shapiro-Wilk's test and independent t-test (p < .05). RESULTS: AH Plus Jet had smaller volume changes (-2.2 to +0.77%) than EndoSequence BC Sealer (-2.0 to +4.0%) (p < .05), in the two tested models. The volume of the root canal sealers decreased over time (p < .05), in vivo. AH Plus Jet results varied between the in vivo and ex vivo results (p < .05), while EndoSequence BC Sealer presented similar volume losses for both experimental models (p > .05). CONCLUSION: EndoSequence BC Sealer lost more volume than AH Plus Jet. The experimental conditions influenced the volumetric change of AH Plus Jet but not the EndoSequence BC Sealer. The ex vivo model should be further explored as a methodological alternative to assess the volumetric changes of root canal sealers without causing harm to animals.

Effect of cleaning materials on microtensile bond strength of resin composite to primary dentin contaminated with root canal sealers.

BACKGROUND: There have been no studies on the bond strength of adhesives with dentin surfaces contaminated with root canal sealers in primary teeth without underlying permanent teeth germs. This study investigated the cleaning materials used for primary tooth dentin contaminated with root canal sealers. The aim was to increase the success rate of root canal treatment in pedodontics clinics and retain the teeth for longer. METHODS: The occlusal enamel layer was removed, followed by the application of root canal sealers (AH Plus or MTA Fillapex) to the dentin and cleaning using different irrigation solutions (saline, NaOCl, and ethanol). The specimens were restored using a self-etch adhesive and composite. Sticks with a thickness of approximately 1 mm were obtained from each sample, and the bond strengths were measured using a microtensile testing device. The interfacial morphology of the bonded space was evaluated using scanning electron microscopy. RESULTS: The control and AH Plus saline groups had the highest bond strengths. The groups cleaned using ethanol had the lowest bond strengths (p < 0.01). CONCLUSION: Cleaning the dentin with saline-soaked cotton pellets provided the best bond strengths. Therefore, saline is the most effective material for removing both epoxy resin- and calcium silicate-based root canal sealers from the access cavity.

Influence of supplement administration of omega-3 on the subcutaneous tissue response of endodontic sealers in Wistar rats.

AIM: Natural substances such as omega-3 have been used in the medical field due to their numerous properties and, in particular, modulating effect on the systemic and local inflammatory processes. Thus, this study evaluated the influence of omega-3 supplementation on the subcutaneous tissue response of endodontic sealers in Wistar Rats. METHODOLOGY: Polyethylene tubes were implanted in the subcutaneous tissue of 48 animals (one empty for control and three filled with Sealapex, AH Plus or Endofill). The animals were treated with omega-3 (TO) or water (TW). Treatments started 15 days before implantation until euthanasia. After 5, 15 and 30 days (n = 8), animals were euthanized and polyethylene tubes and surrounding tissue were removed and processed for histological analysis. The inflammatory reaction was analysed by Haematoxylin and Eosin stain and immunolabelling for IL-6 and TNF-α. The collagen maturity was analysed by picrosirius red stain and calcium deposition by von Kossa stain and polarized light. Results were statistically analysed (p < .05). RESULTS: Amongst TW sealer groups, Endofill evoked a more intense inflammatory infiltrate compared with AH Plus and control in the 30-day period (p = .009). However, in TO sealer groups, there was no difference amongst the sealers and control in all periods (p > .05). Comparing each sealer as a function of the supplementation with water or omega-3, there are differences for Endofill (p = .001) and Sealapex (p = .005) in the 30-day period, presenting lower inflammatory infiltrate in the animals treated with omega-3. A higher percentage of immature fibres was observed at 15 and 30 days in the TO group, compared with the TW group (p < .05). The deposition of calcium particles was observed only by Sealapex in all periods, despite the supplementation procedure. CONCLUSIONS: Omega-3 supplementation influence the tissue reactions of endodontic sealers, modulating inflammation, the immunolabelling of IL-6 and TNF-α, the repair process and it does not interfere with calcium deposition.

Influence of variations in the environmental pH on the solubility and water sorption of a calcium silicate-based root canal sealer.

AIM: To evaluate the influence of pH variation on the solubility and water sorption of a premixed calcium silicate-based root canal sealer (EndoSequence BC Sealer) compared to the gold standard based on epoxy resin (AH Plus Jet) after immersion in distilled water and phosphate-buffered saline (PBS). METHODOLOGY: Solubility and water sorption were evaluated after immersion in distilled water or PBS at several pHs (5, 7 and 12) and the values were calculated as percentages of the original mass after 24 h, 7 and 30 days of immersion. The crystalline structures present in the sealers and surface precipitates were assessed by X-ray diffraction. The Shapiro-Wilk's test revealed that data were normally distributed; thus, statistical analysis was performed using one-way anova and Tukey's tests or independent t-test, assuming a 5% α-error. RESULTS: EndoSequence BC Sealer was associated with significantly greater water sorption and solubility compared to AH Plus Jet in all tested conditions (P < 0.05). The acid environment increased the 24 h solubility of EndoSequence BC Sealer immersed in PBS (P < 0.05) and did not induce significative changes in the water sorption (P > 0.05). Alkaline pH reduced the solubility of EndoSequence BC Sealer and increased that of AH Plus Jet at all experimental times and soaking media (P < 0.05). Alkaline environment also significantly increased the water sorption of AH Plus Jet immersed in PBS (P < 0.05). Immersion in PBS significantly reduced the solubility of EndoSequence BC Sealer and significantly increased that of AH Plus Jet (P < 0.05). Precipitates on the surface of EndoSequence BC Sealer corresponding to hydroxyapatite and calcium carbonate were detected after immersion in PBS at pH 5 and 7 for 30 days. CONCLUSIONS: EndoSequence BC Sealer had significantly greater solubility and water sorption than AH Plus Jet. Although the alkaline pH and soaking media directly influenced the solubility and water sorption of the sealers, the solubility of AH Plus Jet remained within the limits recommended by ISO 6876, whilst the solubility of the EndoSequence BC Sealer did not comply with ISO recommendations in all the conditions tested.

Evaluation of the biological properties of two experimental calcium silicate sealers: an in vivo study in rats.

AIM: To evaluate the biological properties of experimental sealers based on tricalcium silicate and dicalcium silicate, manipulated with polyethylene glycol (CE-1) and with the addition of calcium hypochlorite (CE-2) compared to AH Plus (AHP) and TotalFill BC Sealer (TBC). METHODOLOGY: The tissue reaction caused by the materials in the subcutaneous tissue of rats was evaluated after implantation of polyethylene tubes filled with the materials at 7, 15, 30 and 60 days. Sections were stained with haematoxylin and eosin (HE) for morphological analysis and to evaluated number of inflammatory cells/mm2 (ICs). Sections were used for immunohistochemical detection of interleukin-6 (IL-6) and osteocalcin (OC). The von Kossa method was used to identify calcium precipitation in the capsules. The data were submitted to anova and Tukey's tests, with 5% significance level. RESULTS: At 7 days, CE-1, CE-2 and AHP had higher numbers of ICs. AHP presented higher immunolabelling for IL-6. After 15 days, regarding IL-6, there was no difference between CE-2 and the control group. At 30 days, AHP exhibited the highest number of IC (P < 0.05) and CE-2 and the control group presented the lowest ICs and IL-6-positive cells. After 60 days, all materials exhibited decreases in ICs. CE-2, TBC and the control had the lowest values (P < 0.05). No significant difference was detected between CE-1 and TBC, and between CE-2 and control considering the immunoexpression of IL-6. In this period, AHP had the greatest number of IC and IL-6 (P < 0.05). In all periods, CE-1, CE-2 and TBC sealers had von Kossa-positive structures and OC-immunolabelled cells. CE-2 had higher number of OC-positive cells than the CE-1 and TBC sealers (P < 0.05), in all periods. OC immunolabelling was not observed in the capsules of AH Plus and the control groups. CONCLUSIONS: The experimental sealer and its association with calcium hypochlorite, in addition to TotalFill BC Sealer, were biocompatible and had bioactive potential.

Effect of immersion in distilled water or phosphate-buffered saline on the solubility, volumetric change and presence of voids within new calcium silicate-based root canal sealers.

AIM: To assess the effect of immersion in distilled water or phosphate-buffered saline (PBS) on the solubility, volumetric change and presence of voids of calcium silicate-based root canal sealers (TotalFill BC, Sealer Plus BC and Bio-C), in comparison with the gold standard epoxy resin-based sealer (AH Plus). METHODOLOGY: All properties were evaluated after immersion in distilled water or PBS. Solubility was determined by the percentage of mass loss, whereas volumetric change and presence of voids were evaluated by micro-computed tomography, after 7 days of immersion. The volumetric change and percentage of voids between the baseline (after setting) and the experimental period were calculated. Statistical analysis was performed using one-way anova and Tukey's or Student's t-tests (α = 0.05). RESULTS: The calcium silicate-based sealers had significantly greater solubility and volumetric loss than AH Plus, after immersion in distilled water or PBS (P < 0.05). Bio-C had the greatest solubility (P < 0.05), followed by TotalFill BC and Sealer Plus BC, which were similar (P > 0.05). Regarding the volumetric change, AH Plus had a volume increase, with similar values in distilled water and PBS (P > 0.05). TotalFill BC, Sealer Plus BC and Bio-C had a similar volumetric change (P > 0.05). The calcium silicate-based materials had the greatest solubility and volume loss after immersion in distilled water (P < 0.05). There was no difference in the percentage of voids amongst the sealers, before and after immersion in distilled water or PBS (P > 0.05). CONCLUSIONS: TotalFill BC, Sealer Plus BC and Bio-C had significantly greater solubility and volumetric loss than AH Plus. Although storage in PBS significantly reduced the solubility and volumetric change of calcium silicate-based sealers, their solubility remained above that recommend by ISO 6876. All the sealers evaluated had low and similar voids, even after immersion in distilled water or PBS.

Cytocompatibility, bioactive potential and antimicrobial activity of an experimental calcium silicate-based endodontic sealer.

AIM: To evaluate the cytocompatibility, bioactive potential, antimicrobial and antibiofilm activities of an experimental calcium silicate-based endodontic sealer, in comparison with TotalFill BC Sealer and AH Plus. METHODOLOGY: Cytocompatibility was assessed by methyltetrazolium (MTT) and neutral red (NR) assays, after exposure of the Saos-2 cells to the sealer extracts (1 : 2, 1 : 4, 1 : 8, 1 : 16 and 1 : 32 dilutions) for 24 h. The sealers were manipulated and placed in 12-well culture plates and exposed to ultraviolet light; then, 5 mL of DMEM without serum was added. Cell bioactivity was evaluated by alkaline phosphatase activity (ALP) and Alizarin red staining (ARS). Antimicrobial and antibiofilm activities were evaluated by direct contact test (DCT) on planktonic cells (DCTPC) and modified DCT on biofilm formed in bovine dentine blocks (MDCT). MTT, NR and ALP data were analysed by two-way anova and Bonferroni tests; ARS data by anova and Tukey's tests; and the microbiological data by Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: The experimental sealer, TotalFill BC and AH Plus were not cytotoxic to Saos-2, in comparison with the negative control (P > 0.05). Greater ALP was observed after 7 days of exposure of Saos-2 to AH Plus and the experimental sealer (P < 0.05) when compared to the control. Significantly greater mineralized nodule production was observed for TotalFill BC and the experimental sealer (P < 0.05). In DCTPC, the experimental sealer and TotalFill BC were associated with a significantly greater reduction of E. faecalis (P < 0.05) and eliminated C. albicans. In MDCT, the experimental sealer and TotalFill BC had significantly greater antibiofilm efficacy (P < 0.05). CONCLUSIONS: The experimental calcium silicate-based sealer was cytocompatible, bioactive, antimicrobial against E. faecalis and C. albicans and effective against E. faecalis biofilms, with potential for use in root canal treatment.

Bone tissue response to an MTA-based endodontic sealer, and the effect of the addition of calcium aluminate and silver particles.

AIM: To evaluate bone tissue reactions in rats to an MTA-based endodontic sealer with and without the addition of various concentrations of C3A or C3A + Ag. METHODOLOGY: Bone tissue reactions were evaluated in 45 Wistar rats after 7, 30 and 90 days (n = 5 per period). Three surgical cavities were prepared on the right femur and filled with 0.2 mL MTA Fillapex, MTA Fillapex + C3A and C3A + Ag at various concentrations: AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), EndoSequence BC (Brasseler USA, Savannah, GA, USA) or no sealer (negative control). By the end of each experimental period, animals were randomly euthanized. The samples were histologically processed and analysed using a light microscope. The presence of inflammatory cells, fibres and hard tissue barrier formation was evaluated. Data were analysed statistically using nonparametric tests to compare the differences between groups. Multiple groups were compared using the Kruskal-Wallis and Mann-Whitney U-tests with a Bonferroni correction at P = 0.05. RESULTS: The inflammatory response significantly decreased from 30 to 90 days (P < 0.05). Fibre condensation was similar amongst the groups at 07 and 30 days after intervention (P > 0.05). At 90 days, however, fibres were absent in most specimens of EndoSequence BC Sealer, AH Plus, MTA Fillapex and the control group, whilst they were still observed in samples of the modified sealers (P < 0.05). At 90 days, all specimens of AH Plus, EndoSequence BC Sealer and control group had complete formation of hard tissue barrier. In the MTA Fillapex group, as well as in the modified sealers groups, partial deposition of mineralized tissue was noticed. CONCLUSION: The hypothesis tested that the incorporation of C3A and C3A + Ag particles to MTA Fillapex would improve bone tissue repair was partially accepted, since modified MTA Fillapex did not have the same repair potential as the commercial bioceramic material.

CBCT Performance and Endodontic Sealer Influence in the Diagnosis of Vertical Root Fractures.

AIM: To evaluate the performance of three cone beam computed tomography (CBCT) machines in detecting vertical root fractures (VRFs) in teeth filled with different sealers. MATERIALS AND METHODS: A total of 80 single-rooted premolars were subjected to instrumentation and restoration with gutta-percha + AH Plus sealer, gutta-percha + sealer 26, gutta-percha + fill canal, and gutta-percha without sealer as the control. Half of the samples were randomly subjected to root fracture and all the teeth were scanned by i-CAT (Imaging Sciences International, Hatfield, USA), PreXion (PreXion Inc., San Mateo, USA), and OrthoPhos XG (Sirona Dental System, Bensheim, Germany). Three examiners analyzed the images for the presence of fractures. RESULTS: The highest accuracy was obtained with the PreXion device, with Az = 0.85, while the i-CAT device provided higher sensitivity (0.93). The specificity values observed ranged between 0.75 and 0.70. Chi-squared tests (p > 0.05) demonstrated that the sealers did not exert a significant influence on the diagnosis of VRF. CONCLUSION: It may be concluded that endodontic sealers do not influence the detection of VRF. The PreXion device was the most accurate, having the highest specificity value. CLINICAL SIGNIFICANCE: Radiopaque materials might affect the diagnosis of VRFs because they can simulate fracture lines, leading to false-positive results. Moreover, CBCT machines present different specificities that could exert some influence on that.

Fabrication and characterization of polymer composites for endodontic use.

AIM: To develop a low-density polyethylene-hydroxyapatite (HA-PE) composite with properties tailored to function as a potential root canal filling material. METHODOLOGY: Hydroxyapatite and polyethylene mixed with strontium oxide as a radiopacifier were extruded from a single screw extruder fitted with an appropriate die to form fibres. The composition of the composite was optimized with clinical handling and placement in the canal being the prime consideration. The fibres were characterized using infrared spectroscopy (FTIR), and their thermal properties determined using differential scanning calorimetry (DSC). The tensile strength and elastic modulus of the composite fibres and gutta-percha were compared, dry and after 1 month storage in simulated body fluid (SBF), using a universal testing machine. The radiopacity of the fibres was determined using digital radiography. The interaction of the composites with eugenol was evaluated and compared with gutta-percha. Data of the tensile test were submitted to two-way anova and Bonferroni tests (P < 0.05). RESULTS: The endothermic peaks obtained from the DSC studies showed that the melting point of the HA/PE composites ranged between 110.5 and 111.2 °C, whereas gutta-percha exhibited a melting point at 52 °C. The tensile strength and elastic modulus of the silanated HA/PE composites were significantly higher than those of gutta-percha (P < 0.0001) under dry conditions and 1 month storage in SBF. The gutta-percha in eugenol showed a significant increase in the polymer molar mass, whereas the silanated HA/PE composites were unchanged. Radiological evaluations demonstrated that silanated HA/PE fibres were sufficiently radiopaque. CONCLUSION: Promising materials for endodontic applications have been developed, offering relevant benefits over the traditional materials in terms of mechanical and chemical properties.

Influence of bioceramic sealer residues on the adhesion interface with a universal adhesive in the etch-and-rinse strategy, based on the application protocol and evaluation time.

The aim of this study was to evaluate the effects of the application of universal adhesive in the etch-and-rinse (ER) strategy with a manual brush (MB) or rotary brush (RB) in adhesion to dentin impregnated (WB) or not (NB) with bioceramic sealer, at 24 h and 1 year. Eighty-eight crowns of bovine incisors were divided into four groups (n=22): WB-MB, WB-RB, NB-MB, NB-RB. After the restorative protocol, dentin penetrability was evaluated by confocal microscopy. Bond strength was evaluated by microtensile test. Data were analyzed using one-way ANOVA/Tukey tests (α=0.05). NB-RB and WB-RB exhibited greater extensions of resin tags in dentin. At 24 h, WB-RB and NB-MB showed the highest and lowest values of bond strength, respectively. At 1 year, WB-MB and WB-RB demonstrated the highest bond strength values. The RB increases the formation of resin tags and residues of bioceramic sealer provides higher bond strength in the ER strategy.

Effect of the timing of primary endodontic treatment and dosage of radiation therapy on the filling material removal.

This study investigated the effect of the timing of primary endodontic treatment and dosage of radiotherapy on the remaining filling material (RFM) during endodontic reintervention. 60 single-rooted human mandibular premolars were distributed into five groups (n = 12), according to the timing and dosage of radiation (55Gy or 70Gy): NegativeCG-non-irradiated teeth; Endo-pre-RT55/70-obturation before irradiation (55Gy or 70Gy); Endo-post-RT55/70-obturation and reintervention after irradiation (55Gy or 70Gy). Roots were cleaved and analysed under stereomicroscope and Scanning Electron Microscope to quantify (%) the RFM. Experimental groups had a significantly greater amount (p < 0.05) of RFM in the middle and apical thirds than the control group, except for Endo-pre-RT55 in the middle third (p < 0.0001). The apical third had greater amount of RFM (p < 0.05). Radiation therapy, before and after primary endodontic treatment, increased the amount of RFM, regardless of the dose delivered. When necessary, reintervention preferably must be performed before radiation therapy.

Root canal filling materials for endodontic treatment of necrotic primary teeth: a network meta-analysis.

PURPOSE: To investigate the effect of different root canal filling materials on the change of failure of the endodontic treatment of necrotic primary teeth. METHODS: A literature search was carried out in PubMed/MEDLINE, CENTRAL, Scopus databases, and grey literature up to July 2022 selecting randomised clinical trials related to research question. Two reviewers independently selected the studies, extracted the data, and assessed the bias risk. Root canal filling materials were grouped according to the main component [iodoform (IOD), calcium hydroxide (CAOH), zinc oxide (ZO) or mix (IOD plus CAOH plus ZO) pastes]. Pairwise and network meta-analyses using the mixed treatment comparisons method were performed to compare the number of events (failure) among treatments. Odds ratio and 95% confidence intervals (CI) for calculated. Post-probabilities among treatments were also calculated and interpreted. RESULTS: From 1186 potentially relevant studies, 17 were selected for full-text analysis, and 7 were included in the meta-analysis, totalizing 263 teeth. In the direct evidence, ZO pastes resulted in a higher chance of failure than IOD pastes (OR 7.07 95% CI 1.02, 62.59). In the indirect evidence, there was no difference between the materials. The IOD pastes presented a high probability (81%) of being the treatment associated to lowest number of failures among all treatments. The CAOH pastes presented the highest probability of being the worst option. Studies showed high bias risk. CONCLUSION: There is currently no scientific evidence of the superiority of any one root canal filling material for endodontic treatment of necrotic primary teeth.

Treatment of strip perforation using cold ceramic.

Root perforation may occur at any stage of endodontic treatment and is mostly due to iatrogenic injury and may compromise the outcome of endodontic treatment. Repairing a perforation is difficult and the prognosis depends on various factors such as time, site and size of perforation, and the patient's overall health status. Hence, choosing the most appropriate material can be critical for the dentist. In this case report of a strip-perforation repair, an mineral trioxide aggregate-like material (cold ceramic) that has been shown in previous studies to have favorable properties, was successfully used.

Comparison of the Physical Properties of Three Resin-Based Root Canal Sealers: An In-Vitro Study.

Objectives: This in-vitro study aimed to evaluate the physical properties of three resin-based root canal sealers, including BETA-RCS, AH26, and Adseal. Materials and Methods: Flowability, film-thickness, solubility, and radiopacity of BETA-RCS, AH26, and Adseal sealers were evaluated according to ISO 6876/2012 specifications. Three samples of each sealer were used to test each of the properties. Results: The results revealed that the flow rate (mm) of BETA-RCS, Adseal, and AH26 were 23.06±1.58, 22.5±4.23, and 21.85±1.71, respectively. Film-thickness values (µm) for BETA-RCS, Adseal, and AH26 sealers were 52.33±2.51, 18.66±0.57, and 52±2, respectively. No significant difference was observed regarding film-thickness between AH26 and BETA-RCS (P>0.05), while Adseal showed significantly lower film-thickness (P˂0.05). The highest and lowest solubility were related to BETA-RCS and Adseal, respectively. However, all sealers had acceptable solubility and radiopacity. Conclusion: The findings of the current study suggested that all three root canal sealers including BETA-RCS, AH26, and Adseal had similar properties based on ISO 6876 standard criteria. As such, they could be viable choices for facilitating effective root canal procedures. Further long-term clinical studies are warranted to assess their performance and success rates in actual endodontic cases.

Effect evaluation of different methods for removal of root canal filling materials.

OBJECTIVES: This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals. METHODS: Ninety tooth roots filled by gutta percha or plasticized material (n=45, each) were randomly divided into three groups (n=15). WaveOne (WaveOne group), 1#P drill+WaveOne (1#P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal. The operating time of each canal was recorded and the percentage of residual filling material area was measured on the root canal wall of the mesial and distal dissected root section. The degree of deviation of the root canal after operation was measured for the root samples filled by gutta percha. RESULTS: The type of root filling material and the method of root canal retreatment had no significant effect on the percentage of residual area of the filling material (P>0.05). However, the remaining filling material area of apical 1/3 of the root canal was significantly higher than that of cervical 1/3 of the root canal (P<0.05). The average operating times for removing gutta-percha or plasticized material in the W and 1#P+WaveOne groups were significantly less than that in the P5+ProTaper Universal group (P=0.000). The root canal retreatment methods had no significant effect on the curvature of the root canal (P=0.650). CONCLUSIONS: WaveOne single file's cleaning ability and center positioning ability were similar to those of ProTaper Universal. Moreover, WaveOne can be independently used for most root canals without a pathway when removing the root canal fillings, thereby simplifying the process of root canal retreatment.

Efficacy of Removing Thermafil and GuttaCore from Straight Root Canal Systems Using a Novel Non-Surgical Root Canal Re-Treatment System: A Micro-Computed Tomography Analysis.

The present study aims to evaluate the effectiveness of an XP-endo non-surgical root canal re-treatment system in removing both GuttaCore and Thermafil gutta-percha carrier-based root canal filling materials from straight root canal systems using micro-computed tomography (micro-CT) analysis. The study was performed on 20 single-rooted upper teeth, which were randomly allocated into the following study groups: Group A, Thermafil and AH Plus sealer (n = 10); Group B, GuttaCore and AH Plus sealer (n = 10). Before and after the non-surgical root canal re-treatment procedure, the samples were submitted for a micro-CT analysis. The volume of the root canal filling material (mm3), the volume of the remaining root canal filling material (mm3) and the time (minutes) needed to remove the root canal filling material were also recorded. Student's t-test was used to analyze the results. No statistically significant differences were found between the volume of the remaining root canal filling material in the GuttaCore and Thermafil root canal filling systems at the coronal third (p = 0.782), middle third (p = 0.838) or apical third (p = 0.882) of the straight root canal systems; however, the GuttaCore required a statistically significant (p = 0.037) shorter amount of time (4.72 ± 0.76 min) to be removed than the Thermafil carrier-based root canal filling material (5.92 ± 1.42 min). The XP-endo Finisher non-surgical endodontic re-treatment system removes both GuttaCore and Thermafil gutta-percha carrier-based root canal filling materials from straight root canal systems, although removal of the GuttaCore gutta-percha carrier-based root canal filling material required less time.

Biocompatibility and Bioactive Potential of New Calcium Silicate-based Endodontic Sealers: Bio-C Sealer and Sealer Plus BC.

INTRODUCTION: Bio-C Sealer (BC; Angelus, Londrina, PR, Brazil) and Sealer Plus BC (SPBC; MK Life, Porto Alegre, Brazil) are new ready-to-use bioceramic endodontic sealers. The aim of this study was to evaluate the biocompatibility and bioactive potential of BC and SPBC sealers in comparison with AH Plus (AHP; Dentsply DeTrey Gmbh, Konstanz, Germany) in subcutaneous tissue of rats. METHODS: Polyethylene tubes filled with materials and empty tubes, serving as the control group, were implanted in the subcutaneous tissues of rats. After 7, 15, 30, and 60 days, the tubes with connective tissue were removed, and inflammatory cells (ICs)/mm2 and immunolabeled cells for interleukin (IL)-6 were evaluated. Osteocalcin and von Kossa analysis were also performed. Data were submitted to analysis of variance and Tukey tests, with a significance level of 5%. RESULTS: At 7 days, SPBC showed lower ICs than BC (P < .05). AHP exhibited greater immunolabeled cells for IL-6 (P < .05). After 15 days, BC showed lower ICs and IL-6 compared with other materials. At 30 days, SPBC and AHP showed higher values for ICs (P < .05). After 60 days, calcium silicate sealers did not show statistical difference (P > .05) for ICs and IL-6, with values lower than AHP (P < .05). The materials showed positive structures to von Kossa staining. BC exhibited osteocalcin labeling in all periods. SPBC showed osteocalcin labeling from 15-60 days. AHP and the control group did not exhibit osteocalcin labeling. CONCLUSIONS: BC and SPBC sealers are biocompatible and present bioactive potential.

In vivo evaluation of zinc oxide-propolis mixture as root canal filling material in the primary molars: A 24-month follow-up randomized controlled trial.

BACKGROUND: Pulpectomy is a routine practice in children with pulpal and periapical infections, the success of which depends on the elimination of bacteria from the root canals. Propolis, a natural product with proven antibacterial and anti-inflammatory properties when mixed with zinc oxide powder as root canal filling material, it could provide good success in endodontic therapy of primary teeth. AIM: The aim was to evaluate and compare the clinical effectiveness of zinc oxide-propolis mixture with zinc oxide eugenol (ZOE) as root canal filling material in nonvital primary molars. SETTINGS AND DESIGN: This was a 2-arm, parallel group randomized controlled trial with blinded outcome assessment. MATERIALS AND METHODS: Forty primary molars from children aged 4-8 years requiring pulpectomy treatment were randomly allocated into two groups according to the obturating material used: zinc oxide-propolis mixture (test group) and ZOE (control group). All the pulpectomy treated teeth were finally restored with stainless steel crowns, and the children were recalled at 6, 12, and 24 months for postoperative clinical and radiographic evaluation. STATISTICAL ANALYSIS: Chi-square test was used to analyze the data. RESULTS: The overall success rate of pulpectomy with zinc oxide-propolis mixture and ZOE was found to be 95% and 70%, respectively, and the difference was statistically significant (P = 0.037). Zinc oxide-propolis mixture has shown a success rate of 100% at 6 months and 95% at 12 and 24 months follow-up, whereas ZOE has shown 80% success rate at 6 and 12 months, and it declined to 70% at 24-month follow-up. CONCLUSION: Zinc oxide-propolis mixture demonstrated good clinical and radiographic success at the end of 24 months, and hence, it can be considered as an alternate root canal filling material in the primary teeth.

The Efficacy of Rotary, Reciprocating, and Combined Non-Surgical Endodontic Retreatment Techniques in Removing a Carrier-Based Root Canal Filling Material from Straight Root Canal Systems: A Micro-Computed Tomography Analysis.

The aim of this study is to analyze and compare the efficacy of three non-surgical endodontic retreatment techniques in removing a carrier-based root canal filling material from straight root canal systems. The study was performed on 99 single-rooted extracted teeth using the ProTaper Gold endodontic rotary system up to the F2 file (Dentsply Maillefer, Baillagues, Switzerland), which were sealed with GuttaCore (Dentsply Maillefer, Ballaigues, Switzerland) and AH plus epoxy resin sealer (Dentsply DeTrey, Konstanz, Germany) and randomly assigned to the following non-surgical retreatment techniques: ProTaper Retreatment endodontic rotary instruments (D1-D3 files, Dentsply Maillefer, Ballaigues, Switzerland; n = 33, PTR), Reciproc Blue endodontic reciprocating instrument (R50, VDW, Munich, Germany; n = 33, RCB50), and a combined root canal retreatment technique between Gates-Glidden drills (sizes #3 and #2, Dentsply Maillefer, Ballaigues, Switzerland) and Hedstrom files (file size 35, 30, and 25, Dentsply Maillefer, Ballaigues, Switzerland; n = 33; H-GG). All of the teeth were submitted twice to a micro-computed tomography (micro-CT) scan, before and after non-surgical endodontic retreatment procedures. The volume of root canal filling material (mm3), volume of remaining root canal filling material (mm3), non-surgical endodontic retreatment working time (min), proportion of remaining root canal filling material (%), and efficacy of root canal filling material removal between the non-surgical endodontic retreatment techniques were analyzed using ANOVA one-way statistical analysis. Statistically significant differences were observed between the proportions of remaining root canal filling material of PTR and H-GG (p = 0.018), between the non-surgical endodontic retreatment working times (min; p < 0.001), and between the efficacies of root canal filling material removal by the non-surgical endodontic retreatment techniques (p = 0.009). However, the non-surgical endodontic retreatment systems allow for similar carrier-based root canal filling material removal.