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The evolution of biomaterials engineering allowed for the development of products that improve outcomes in the medical-dental field. Bioglasses have demonstrated the ability to either compose or replace different materials in dentistry. This study evaluated the cytotoxicity, biocompatibility, calcium deposition, and collagen maturation of 45S5 bioglass experimental paste and Bio-C Temp, compared to calcium hydroxide (Ca(OH)2) paste. The 45S5 bioglass and Ca(OH)2 powder were mixed with distilled water (ratio 2:1); Bio-C Temp is ready-for-use. Dental pulp cells were exposed to the materials' extracts (1:2 and 1:4 dilutions; 24, 48, and 72 h) for MTT and live/dead analyses. Polyethylene tubes filled with the pastes, or left empty (control), were implanted on the dorsum of 16 rats. After 7 and 30 days (n = 8/period), the rats were euthanized and the specimens were processed for hematoxylin-eosin (H&E), von Kossa (vK), and picrosirius red (PSR) staining, or without staining for polarized light (PL) birefringence analysis. A statistical analysis was applied (p < 0.05). There was no difference in cell viability among Ca(OH)2, 45S5 bioglass, and the control, across all periods and dilutions (p > 0.05), while Bio-C Temp was cytotoxic in all periods and dilutions compared to the control (p < 0.05). Regarding biocompatibility, there was a reduction in inflammation from 7 to 30 days for all groups, without significant differences among the groups for any period (p > 0.05). The fibrous capsules were thick for all groups at 7 days and thin at 30 days. All materials showed positive structures for vK and PL analysis. At 7 days, the control and 45S5 bioglass showed more immature collagen than the other groups (p < 0.05); at 30 days, 45S5 bioglass had more immature than mature collagen, different from the other groups (p < 0.05). In conclusion, Bio-C Temp presented cytotoxicity compared to the other materials, but the three pastes showed biocompatibility and induced calcium deposition. Additionally, the bioglass paste allowed for marked and continuous collagen proliferation. This study contributed to the development of new biomaterials and highlighted different methodologies for understanding the characteristics of medical-dental materials.

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OBJECTIVES: This systematic review and meta-analysis (SRM) aimed to evaluate the efficacy of laser phototherapy (LPT) on the reduction in postoperative pain (PP) of endodontic origin after conventional/non-surgical reintervention of root canals. METHODS: This SRM was registered with PROSPERO (CRD42021243500) and followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Meta-analysis was conducted using R software with the "META" package, the mean difference (MD) measure of effect was calculated, and the fixed effect model was applied with a 95% confidence interval (CI). The Cochrane collaboration scale was used to assess the risk of bias and the GRADE tool to assess the quality of evidence. RESULTS: Initially, 1028 articles were found, and five articles were included. Most studies were classified as "low" risk of bias. Of the five clinical studies, four showed a significant decrease in PP after endodontic reintervention in the LPT groups compared to the control group, especially in the first four days after the intervention. In symptomatic teeth with multiple roots, LPT led to less PP at 24 h (MD -0.52 [-1.03; -0.02] p = .04). However, no significant difference between the groups was found at 48 and 72 h (p > .05). The certainty of the evidence was classified as low. CONCLUSION: Despite the limitations of this SRM, LPT was shown to be a promising alternative for reducing and controlling PP in conventional endodontic reintervention. CLINICAL SIGNIFICANCE: The use of LPT in endodontic reintervention may be a safe and promising alternative to clinically efficacious agent for use in the management of PP in this procedure.

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INTRODUCTION: This study evaluated the effects of cigarette smoke inhalation (CSI) on apical periodontitis (AP) induced in rats by histometric, immunohistochemical, and microtomographic analysis. METHODS: A total of 32 male Wistar rats were divided into 4 experimental groups (n = 8): control, CSI, AP, and CSI + AP. Rats in the CSI and CSI + AP groups inhaled cigarette smoke by remaining inside a smoking chamber for 8 minutes 3 times a day for 50 days. After 20 days of smoke inhalation, rats in the AP and CSI + AP groups had the pulp of their first right lower molar exposed to induce AP. Blood was collected on day 50 to evaluate nicotine and serum cotinine levels. The animals' mandibles were removed for histologic processing to evaluate bone resorption by histometric, immunohistochemical (receptor activator of nuclear factor kappa B ligand/osteoprotegerin), and microtomographic analysis. The Student t test was applied. RESULTS: Histometric analysis showed a larger area of bone resorption (P < .05) and microtomographic analysis found greater resorption volume (P < .001) for the CSI + AP group compared with the AP group. The CSI + AP group presented a high RANKL immunostaining pattern compared with the AP group (P < .001). CONCLUSIONS: CSI increased bone resorption caused by AP.

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OBJECTIVE: To evaluate the effects of cigarette smoke inhalation on the immune-inflammatory profile of experimental apical periodontitis in rats. METHODOLOGY: In total, 32 male Wistar rats were divided into four groups (n = 8): AP-induced apical periodontitis; S-cigarette smoke inhalation; APS-induced AP and cigarette smoke inhalation; and C (control)-neither AP nor cigarette smoke inhalation. To induce cigarette smoke inhalation, the animals were kept in a chamber filled with tobacco smoke for 8 min thrice a day for 50 days. AP was induced 20 days after inhalation initiation by exposing their coronary pulp to their oral environment for 30 days. After animals were euthanized, their right hemimaxillae were removed for histopathological, semi-quantitative and immunohistochemical (F4/80, CD206 and iNOS) analyses. RESULTS: Quantitative data showed a moderate number of inflammatory infiltrates in AP and an intense number in APS (p < .05). Comparing F4/80+ cells showed no statistically significant differences among groups, but we found more CD206+ cells in AP than in C and S (p > .05). INOS+ immunostaining showed a significant increase in AP and APS, when compared with C and S (p < .05). APS had more iNOS+ cells than AP (p < .05). CONCLUSION: Cigarette smoke inhalation worsened AP, leading to a predominantly pro- inflammatory profile in our experimental model.

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Biocompatibility and biomineralization of root canal dressings are important requirements for periapical healing. This study evaluated the inflammatory response, biomineralization and tissue repair by collagen fiber maturation in the subcutaneous tissue of rats. Eighteen Wistar rats (n = 6) received subcutaneous implants: calcium hydroxide + propylene glycol [CH+P], calcium hydroxide + propylene glycol + iodoform [CH+P+I], iodoform + carbowax [I+Cwax] and carbowax [Cwax]. Extra empty tubes were used as a control [C]. After 7, 15 and 30 days, the implants were removed with surrounding tissue for staining of hematoxylin-eosin, Von Kossa, picrosirius red and without staining for analysis under polarized light. Results were analyzed via Kruskal-Wallis followed by Dunn testing for nonparametric data and ANOVA followed by a Tukey post hoc test for parametric data (p < 5%). At 7 days, all groups showed a moderate inflammatory reaction and thick fibrous capsule, except the [Cwax] group, with a severe inflammatory infiltrate (p < 0.05). After 15 days, all groups but control had a decrease in inflammatory response. At 30 days, all groups presented a mild reaction and thin fibrous capsule (p > 0.05). Only groups containing calcium hydroxide were found to be positive using Von Kossa staining and polarized light in all periods. At 7 days, all groups showed a higher proportion of immature fibers. At 15 days, the [CH+P] and [Cwax] groups increased their proportion of mature/immature fibers. At 30 days, only the [CH+P] group presented a significant prevalence of mature collagen fibers (p < 0.05). All groups showed biocompatibility, but only groups containing calcium hydroxide induced biomineralization. The addition of iodoform delayed tissue healing.

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The purpose of this study was to evaluate, in vivo, the biocompatibility, biomineralization, collagen maturation and the in vitro antibacterial and cytotoxicity of resinous endodontic sealers containing calcium hydroxide. Forty rats were implanted with polyethylene tubes containing Sealer 26, Sealer Plus, Dia-ProSeal and an empty tube, examined after 7, 15, 30 and 60 days. Antimicrobial activity was evaluated against Enterococcus faecalis by Agar Diffusion Test (ADT) through inhibition zones. For cytotoxicity, undifferentiated pulp cells (OD-21) were cultured and assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, exposed to dilution of serial extracts at 6, 24, 48h. Cytotoxicity was analyzed by two-way ANOVA and Bonferroni correction. Kruskal-Wallis test followed by Dunn test was performed for nonparametric data (p<0.05). MTT assay revealed cell proliferation affected by sealers extract in all periods (p<0.0001), except for Dia-Proseal and Sealer Plus ⅛ dilution. Subcutaneous analysis showed at day 7th moderate inflammatory infiltration. After 30 days, Sealer 26 still showed moderate inflammatory infiltrate compared to mild inflammation from control and Dia-ProSeal (p = 0.006). At day 60th, all groups showed similar mild inflammatory infiltrate (p>0.05). Sealer 26 induced more biomineralization than other sealers in all periods. At 7 and 15 days, all sealers had significant percentage of immature collagen fibers. After 60 days Sealer 26 showed more mature fibers compared to other sealers (p<0.001). All sealers had a smaller zone of inhibition than chlorhexidine, but with no significant difference among any group (p>0.05). All sealers showed satisfactory biological responses with in vitro/in vivo biocompatibility and antimicrobial activity against planktonic bacteria. Sealer 26 induced more biomineralization than Sealer Plus and Dia-ProSeal.

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AIM: The aim of this study was to evaluate the effects of cigarette smoke inhalation (CSI) on inflammation, pro-inflammatory mediators and haematological parameters in rats with induced apical periodontitis (AP). METHODOLOGY: Thirty-two 3-month-old male Wistar rats were divided into four experimental groups (n = 8): C-Control; S-rats with CSI; AP-rats with AP; and SAP-rats with CSI + AP. Animals in groups S and SAP inhaled cigarette smoke by remaining inside a smoking chamber for 8 min, three times daily, for 50 days. After 20 days of smoke inhalation, animals in AP and SAP groups had the pulps of the lower right first molar exposed to oral environment for 30 days to induce AP. In these subsequent 30 days, animals in group S and SAP continued with CSI. On Day 50, animals were euthanized and mandibles were histologically processed to assess inflammatory infiltrate, immunohistochemical interleukins (IL-1ß, IL-6 and TNF-α), and blood samples collected for laboratory analysis. The Mann-Whitney test was performed for non-parametric data and the pairwise analyses of Student's t-test for parametric data, with a significance level of p < .050. RESULTS: Inflammatory infiltrate was moderate in AP group and more severe in the SAP (p = .010). The interleukins IL-6, IL-1ß and TNF-α were higher in SAP group (p < .001) when compared to the AP group. A greater number of red blood cells (p = .010), haemoglobin (p = .007) and neutrophils (p = .014) were observed in the SAP group in comparison with the AP group. CONCLUSION: Cigarette smoke inhalation induced a more severe inflammatory infiltrate, with increased levels of pro-inflammatory cytokines and changes in haematological parameters in rats with induced AP. Thus, CSI aggravated AP, exacerbating the inflammatory response.

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This research evaluated, in vivo, the accuracy of three electronic apex locators - EALs (Root ZXII, E-PEX and FIND) in teeth with vital pulp submitted to biopulpectomy, preserving the periodontal stump. For this study, 90 single-rooted teeth with extraction indication were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed. The cervical and middle thirds of root canals were instrumented with Reciproc R25, and the K#15 file was used as a standard instrument to determine working length, forming 2 groups: Constriction (insertion of the instrument until the apical constriction limit) and Foramen (insertion of the instrument until the foramen and then repositioning at constriction, without removing the file from the canal). The hand file was stabilized with a light-cured flow resin. After extraction, the samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis using Kruskal-Wallis and Dunn tests (p<0.05). There was a statistically significant difference in the abilities of the EALs to detect the apical constriction after reaching the foramen with Root ZX II showing higher accuracy (89%). However, there was no difference in the accuracy of the three EALs in detecting the apical constriction without reaching the foramen. Based on the present results, we conclude that EALs may show accurate measures in detecting apical constriction and foramen, even without damaging the periodontal stump in biopulpectomy.

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OBJECTIVES: This study compared the cytotoxicity, biocompatibility, and tenascin immunolabeling of a new ready-to-use hydraulic sealer (Bio-C Sealer) with MTA-Fillapex and white MTA-Angelus. MATERIALS AND METHODS: L929 fibroblasts were cultivated and exposed to undiluted and diluted material extracts. Polyethylene tubes with or without (the control) the materials were implanted into the dorsa of rats. At 7 days and 30 days, the rats were euthanized, and the specimens were prepared for analysis; inflammation and immunolabeling were measured, and statistical analysis was performed (p < 0.05). RESULTS: MTA-Fillapex exhibited greater cytotoxicity than the other materials at all time points (p < 0.05). The undiluted Bio-C Sealer exhibited greater cytocompatibility at 6 and 48 hours than white MTA-Angelus, with higher cell viability than in the control (p < 0.05). White MTA-Angelus displayed higher cell viability than the control at 24 hours, and the one-half dilution displayed similar results at both 6 and 48 hours (p < 0.05). At 7 days and 30 days, the groups exhibited moderate inflammation with thick fibrous capsules and mild inflammation with thin fibrous capsules, respectively (p > 0.05). At 7 days, moderate to strong immunolabeling was observed (p > 0.05). After 30 days, the control and MTA-Fillapex groups exhibited strong immunolabeling, the white MTA-Angelus group exhibited moderate immunolabeling (p > 0.05), and the Bio-C Sealer group exhibited low-to-moderate immunolabeling, differing significantly from the control (p < 0.05). CONCLUSIONS: Bio-C Sealer and white MTA-Angelus exhibited greater cytocompatibility than MTA-Fillapex; all materials displayed adequate biocompatibility and induced tenascin immunolabeling.

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Aims: The aim of this study was to evaluate the biocompatibility of resinous root canal sealers: Sealer 26, AH plus, and SK Seal Root Canal Sealer in the subcutaneous tissue of rats. Subjects and Methods: Twenty-four Wistar rats received polyethylene tubes containing the sealers and empty tubes as control (n = 6). After 7, 15, 30, and 60 days, animals were killed and polyethylene tubes were removed with the surrounding tissues. The specimens were embedded in paraffin, processed for hematoxylin-eosin and immunohistochemistry assessed for fibronectin (FN) and tenascin (TN). Statistical Analysis Used: Data were tabulated and analyzed via Kruskal-Wallis and Dunn's test (P < 0.05). Results: All groups induced a moderate inflammatory reaction after 7 and 15 days (P > 0.05); after 30 days, a mild inflammatory infiltrate was observed in control groups, and moderate in sealers groups (P > 0.05); all groups showed mild inflammatory infiltrate at 60 days (P > 0.05). Overall, the fibrous capsule was considered thick only on the 7th day and became thin over time. All groups had expression for FN and TN in all analyzed periods, with high immunolabeling in sealers groups when comparing with the control group (P < 0.05). Conclusion: All sealers demonstrated biocompatibility and induced FN and TN expression.