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.

Influence of melatonin supplementation on tissue response of endodontic sealers in Wistar rats.

OBJECTIVE: This study evaluated the influence of melatonin supplementation on tissue's response of endodontic sealers in Wistar rats. METHODOLOGY: Forty-eight rats received subcutaneous implants of four polyethylene tubes: one empty (control) and three filled with endodontic sealers (AH Plus, Endofill and Sealapex). Half of the animals were supplemented with melatonin (ME) and the remaining treated with water (WA) for 15 days before the implantation until euthanasia, forming the groups: control-WA, AH Plus-WA, Endofill-WA, Sealapex-WA, Control-ME, AH Plus-ME, Endofill-ME and Sealapex-ME. After 5, 15 and 30 days, (n = 8) tubes were removed and evaluated in H&E., immunohistochemistry, PSR, VK and POL. The results were statistically analyzed (p < 0.05). RESULTS: In animals treated with water, Endofill-WA evoked more intense inflammatory infiltrate compared to AH Plus-WA and Control-WA in a 30-day period (p < 0.05). In animals supplemented with melatonin, there was any difference among endodontic sealers' response in any period of analysis (p > 0.05). Comparing the individual response of each sealer, over a 30-day period, Endofill-ME and Sealapex-ME showed less inflammatory infiltrate compared to Endofill-WA and Sealapex-WA, respectively (p < 0.05). Immunostaining for IL-6 and TNF-α was less intense for all groups in animals supplemented with melatonin, in most periods, except for the Endofill sealer (p < 0.05). Furthermore, Endofill-ME at 5 days and AH-Plus-ME at 30 days showed a higher percentage of mature collagen fibers compared to the Endofill-WA and AH Plus-WA, respectively (p < 0.05). Positive structures for von Kossa staining and birefringent to polarized light were observed only for Sealapex-WA and Sealapex-ME in all periods. CONCLUSIONS: It can be concluded that melatonin influences the tissue response to endodontic sealers, modulating the inflammatory and reparative process.

Antimicrobial effectiveness of ultrasonic irrigation in root canal treatment: a systematic review of randomized clinical trials and meta-analysis.

OBJECTIVE: The objective of this systematic review and meta-analysis (SRM) was to answer the question as to whether the use of ultrasonic irrigation (UI) results in better antimicrobial activity in root canal disinfection compared to conventional irrigation (CI). METHODS: A literature search was performed in the main scientific databases, carried out until October 2021. The eligibility criteria were randomized clinical trials (RCTs). Two meta-analyses were conducted using R software with the "META" package. The mean difference (MD) and odds ratio (OR) measure of effect were calculated. The fixed effect model was applied with a 95% confidence interval. The Cochrane collaboration scale was used to assess risk of bias and the GRADE tool to assess the quality of evidence. RESULTS: A total of 1782 records were screened, and 12 studies meeting the criteria were included in this review. A low risk of bias was observed for most domains, except allocation concealment that was considered unclear. The certainty of evidence was classified as moderate in the OR meta-analyses and low in the MD meta-analyses. Ultrasonic irrigation resulted in a better antimicrobial effect in both meta-analyses, MD 1.42 [1.60; 1.23] p < 0.0001, I2 = 80%; and OR 3.86 [1.98; 7.53] p< 0.0001, I2 = 28.7%. CONCLUSION: Within the limitations of this SRM, UI presented better antimicrobial efficacy than CI. CLINICAL RELEVANCE: UI should be used by clinicians as it promotes better antimicrobial efficacy in patients undergoing endodontic treatment.

Interleukin-6, tumor necrosis factor-α, and CD5 immunolabeling of new experimental endodontic sealer and repair material.

The aim of this study was to evaluate the biocompatibility and immunoinflammatory response of the Sealepox and Sealepox-RP, based on interleukin (IL)-6, tumor necrosis factor (TNF)-α, and CD5 immunolabelling. The ProRoot MTA (PRMTA) was used for comparison. Polyethylene tubes (1.0-mm internal, 1.6-mm external diameter, and 10.0-mm length; ISO 10993) with or without (control) materials were randomly implanted in the dorsum of 35 rats (4 per rat). After 7, 15, 30, 60, and 90 days (n = 7), the tubes were removed for histological and immunohistochemical analysis. The Kruskal-Wallis and Dunn's test for non-parametric data and, ANOVA and Tukey test for parametric data were used (P < 0.05). Hematoxylin and eosin staining revealed that the concentration of inflammatory cells decreased over time with no differences between groups in all periods (P > 0.05). Regarding IL-6 immunostaining, there was no difference at 7 days (P > 0.05); all groups decreased over time, being faster for the PRMTA group and also, with no differences between groups in the last period (P > 0.05). For TNF-α, at 7 days there was no difference between groups (P > 0.05); there was an increase at 15 days for PRMTA and, at 30 and 60 days, for PRMTA and Sealepox compared to the control (P < 0.05). At 90 days, Sealepox RP showed the lowest immunostaining being similar to the control (P > 0.05). Regarding CD5 cells, at 7 days, there was high immunostaining for PRMTA compared to the control (P < 0.05); and significant reduction over time with difference for all groups at 30 and 60 days. (P < 0.05); Sealepox was similar to the control in all periods (P > 0.05). Sealepox RP showed the highest immunostaining at 15 days, being different from the control and PRMTA (P < 0.05); in the other periods it was similar to the control (P > 0.05). It can be concluded that Sealepox and Sealepox-RP were biocompatible and demonstrated similar immunoinflammatory response regarding IL-6, TNF-α, and CD5 compared to PRMTA.

Postoperative pain after root canal filling with bioceramic sealers: a systematic review and meta-analysis of randomized clinical trials.

The aim of this systematic review and meta-analysis (SRM) was to assess postoperative pain (PP) after endodontic treatment with bioceramic root canal sealer compared to AH Plus® sealer. This SRM was carried out in accordance with the items on the PRISMA 2020 checklist and Cochrane guidelines and registered in PROSPERO (CRD42021259283). Only randomized clinical trials (RCTs) were included. Meta-analysis was conducted using R software, the standardized means difference (SMD) measure of effect was calculated for quantitative variables, and the odds ratio (OR) for binary variables. The Cochrane tool (RoB 2.0) was used to assess the risk of bias, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of evidence. Qualitative and quantitative analysis included 18 and 17 studies, respectively. For quantitative variables, the bioceramic root canal sealer presented less occurrence of postoperative pain than the AH Plus® sealer in 24 h (SMD - 0.17 [- 0.34; - 0.01], p = 0.0340). For binary variables, there was no difference observed between the sealers evaluated, except for sealer extrusion where the bioceramic group had lower post-filling material extrusion (OR 0.52 [0.32; 0.84], p = 0.007). Regarding the risk of bias analysis, low risk was observed for most domains, except allocation that was considered unclear, while the certainty of evidence ranged from moderate to low. The results showed that bioceramics sealers reduced postoperative endodontic pain only after 24 h and showed less sealer extrusion compared to the AH Plus® sealer. However, more robust and standardized clinical trials are needed to confirm the results with less heterogeneity and higher quality of evidence.

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.

Postoperative pain in root canal treatment with ultrasonic versus conventional irrigation: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The objective of this systematic review and meta-analysis (SRM) was to answer the question whether the use of ultrasonic irrigation (UI) results in less postoperative pain (PP) compared to conventional irrigation (CI). METHODS: A literature search was performed within the main scientific databases carried out until May 2021. The eligibility criteria were randomized clinical trials (RCTs). 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 risk of bias and the GRADE tool to assess the quality of evidence. RESULTS: Six RCTs were included for systematic review and four for meta-analysis. UI resulted in less PP in 3 of 5 periods, at 6 h (MD - 1.40 [CI - 2.38 to - 0.42] p = 0.0052), 24 h (MD - 0.73 [CI - 1.07 to - 0.39] p = 0.0001), and 48 h (MD - 0.36 [CI - 0.59 to - 0.13] p = 0.022). However, PP showed no significant differences between the groups at 72 h and 7 days (p > 0.05). A low risk of bias was observed for most domains, except allocation that was considered unclear. The certainty of evidence was classified as moderate (24 h, 48 h, and 7 days) and low (6 and 72 h). CONCLUSION: Within the limitations of this SRM, UI presented less occurrence of PP than CI. Further randomized clinical trials are needed to corroborate these findings. CLINICAL RELEVANCE: UI should be used by clinicians as it reduces postoperative pain in patients undergoing endodontic treatment.

Biological and antimicrobial properties of the association Ambroxol and a water-soluble viscous liquid as a vehicle for a tricalcium silicate-based sealer.

This study aimed to investigate the antimicrobial and biological properties of Ambroxol associated with glycerin (GLI), propylene glycol (PG), and polyethylene glycol (PEG) as a possible vehicle for an experimental tricalcium silicate sealer, with the intention of developing a new biomaterial. Mouse undifferentiated dental pulp cells (OD-21) were cultured, and the effects of different association on cell proliferation and inflammatory cytokine production were investigated. Antimicrobial adhesion of Enterococcus faecalis to setting sealers at 2 h was evaluated. Polyethylene tubes containing experimental sealers and empty tubes were implanted into dorsal connective tissues of 12 male 3- to 4-months-old Wistar rats (250-280 g). After 7 and 30 days, the tubes were removed and processed for histological and immunohistochemical analyses. ANOVA followed by Bonferroni correction and ANOVA followed by Tukey test was used for parametric data and Kruskal-Wallis followed by Dunn for nonparametric (p < 0.05). Cell proliferation was dose-dependent, since all association were cytotoxic at higher concentrations; however, Ambroxol-PEG showed significantly higher cytotoxicity than other association (p < 0.05). In addition, irrespective of the association, no cytokine production was observed in vitro. Ambroxol-GLI reduced bacterial viability, whereas Ambroxol-PEG increased (p < 0.05). Histological examination showed no significant difference in the inflammatory response (p > 0.05) and mineralization ability in all association. Additionally, IL-1ß and TNF-α were upregulated on Ambroxol-PEG in relation to Control at 07 days (p < 0.05). Ambroxol-GLI was the best vehicle for experimental tricalcium silicate sealer, as it promoted an increase in antimicrobial activity without altering the inflammatory response or mineralization ability.

Excessive caffeine intake increases bone resorption associated with periapical periodontitis in rats.

AIM: To evaluate the effect of excessive caffeine intake on the inflammation/resorption processes associated with periapical periodontitis (PP) in rats. METHODOLOGY: Sixteen Wistar rats were used. Periapical periodontitis was induced in the four first molars in each animal. The animals were arranged into two groups: control (C)-rats with periapical periodontitis; and caffeine (CAF)-rats with periapical periodontitis under caffeine administration protocol. The CAF animals received 10 mg/100 g of body weight/day of caffeine via gavage starting fifteen days before PP induction and continuing for thirty more days until euthanasia. On the 30th day, the animals were euthanized and the jaws removed for microcomputed tomography, histological and immunohistochemical analysis for RANKL, OPG, TRAP, IL-10, TNF-⍺ and IL-1ß. The Mann-Whitney test was performed for nonparametric data, and Student's t test was performed for parametric data, using p < .05. RESULTS: There was no significant difference in the weight change between the groups. The median score of the inflammatory process was significantly greater in the CAF group (3) compared with the C group (2), p = .0256. Bone resorption was greater in the group consuming caffeine (1.08 ± 0.15 mm3 ) compared with the C group (0.88 ± 0.10 mm3 ), p = .0346. The immunolabelling for RANKL, TRAP and IL-1ß was significantly higher in the CAF group when compared to the control, p < .05. No differences were found for the OPG, IL-10 and TNF-⍺ immunolabelling. CONCLUSION: Excessive caffeine exposure via gavage in rats was able to exacerbate the volume of periapical bone destruction, and the inflammatory pattern deriving from periapical periodontitis altering the expression of RANKL, IL-1ß and TRAP.

Effect of red wine or its polyphenols on induced apical periodontitis in rats.

AIM: To evaluate the effect of red wine consumption or its polyphenols on the inflammation/resorption processes associated with apical periodontitis in rats. METHODOLOGY: Thirty-two three-month-old Wistar rats had apical periodontitis induced in four first molars and were then arranged into four groups: control (C)-rats with apical periodontitis; wine (W)-rats with apical periodontitis receiving 4.28 ml/kg of red wine; resveratrol+quercetin (R+Q)-rats with apical periodontitis receiving 4.28 ml/kg of a solution containing 1.00 mg/L of quercetin and 0.86 mg/L of resveratrol and alcohol (ALC)-rats with apical periodontitis receiving the alcoholic dose contained in the wine. The oral gavage treatments were administered daily, from day 0 to day 45. On the 15th day, apical periodontitis was induced, and on the 45th day, the animals were euthanized. Histological, immunohistochemical (RANKL, OPG, TRAP, IL-10, TNF-⍺ and IL-1ß) and micro-computed tomography for bone resorption analysis were performed in the jaws. The Kruskal-Wallis with Dunn's test was performed for nonparametric data, and the anova with Tukey's test for parametric data, p < .05. RESULTS: The median score of the inflammatory process was significantly lower in the R+Q group (1) compared to the C (2) (p = .0305) and ALC (3) (p = .0003) groups, and not different from the W (1.5) group. The immunolabeling for OPG was significantly higher in the R+Q group (p = .0054) compared to all groups; the same was observed for IL-10 (p = .0185), different from groups C and ALC. The R+Q group had the lowest TRAP cell count (p < .0001), followed by the W group, both inferior to C and ALC groups. The lowest bone resorption value was in the R+Q group (0.50mm3  ± 0.21mm3 ), significantly lower (p = .0292) than the C group (0.88mm3  ± 0.10mm3 ). The W group (0.60 mm3  ± 0.25 mm3 ) and R+Q group had less bone resorption compared to the ALC group (0.97 mm3  ± 0.22 mm3 ), p = .0297 and p = .0042, respectively. CONCLUSION: Red wine administration to rats for 15 days before induction of apical periodontitis decreased inflammation, TRAP marking and periapical bone resorption compared to alcohol. Resveratrol-quercetin administration reduced the inflammatory process in apical periodontitis, periapical bone resorption, and altered the OPG, IL-10 and TRAP expression compared to C and ALC groups.

Biocompatibility and biomineralization assessment of mineral trioxide aggregate flow.

OBJECTIVE: Evaluate, in vivo, the biocompatibility via subcutaneous inflammatory tissue response and mineralization ability of the new MTA Flow compared to MTA Angelus and ProRoot MTA. MATERIALS AND METHODS: Forty male Wistar rats were assigned and received subcutaneous polyethylene tube implants containing the test materials and a control group with empty tube (n = 10 animals/group). After days 7, 15, 30, and 60, the animals were euthanized and the polyethylene tubes were removed with the surrounding tissues. Inflammatory infiltrate and thickness of the fibrous capsule were histologically evaluated. Mineralization was analyzed by Von Kossa staining and under polarized light. Data were analyzed via Kruskal-Wallis and Dunn's test with a significance level of 5%. RESULTS: MTA Angelus induced the mildest reaction after 7 (P > .05) and 15 days (P < .05) followed by MTA Flow, both cements achieving mild inflammatory reaction after 15 days. ProRoot MTA induced a severe inflammation on day 7 and was reducing after day 15 (P > .05). No difference was observed after days 30 or 60 (P > .05). Von Kossa staining and birefringent structures were positive to all materials. CONCLUSIONS: At the end of the experiment, the novel MTA Flow showed biocompatibility and induced biomineralization in all time periods. CLINICAL RELEVANCE: The final consistence obtained in MTA Flow may facilitate several procedures, indicating that the MTA Flow has a promising application in endodontics.

Biocompatibility and biomineralization ability of Bio-C Pulpecto. A histological and immunohistochemical study.

AIM: To evaluate the inflammatory response, biomineralization and production of osteocalcin (OCN), osteopontin (OPN), and bone sialoprotein (BSP) of a new root filling material for primary teeth (Bio-C Pulpecto) compared to MTA. DESIGN: Polyethylene tubes containing Bio-C Pulpecto, MTA, and empty tubes were implanted into the dorsal connective tissue. After 7, 15, 30, 60, and 90 days, the tubes with surrounding tissue were removed and histologically processed to be analysed using haematoxylin and eosin, von Kossa staining, or no staining for observation under polarized light and immunohistochemistry for the detection of OCN, OPN, and BSP. The Kruskal-Wallis test was used followed by Dunn's test. The significance level was set at 5%. RESULTS: The inflammatory response observed with MTA and Bio-C Pulpecto was more exacerbated until the 15th day and decreased from 30 days on. No significant difference was found between control, MTA, and Bio-C Pulpecto (P > 0.05). Bio-C Pulpecto and MTA showed positivity for von Kossa and birefringent to polarized light. The immunolabelling for OCN, OPN, and BSP was more intense for MTA and Bio-C Pulpecto on days 60 and 90 (P > 0.05). CONCLUSION: Bio-C Pulpecto was biocompatible, induced biomineralization and was immunopositive for osteogenic markers such as OCN, OPN, and BSP, similarly to MTA.

Endodontic infections increase leukocyte and lymphocyte levels in the blood.

OBJECTIVES: The aim of this study was to determine whether the presence of single or multiple apical periodontitis (AP) alters blood cell counts and cytokine production. MATERIAL AND METHODS: Thirty rats were divided into three groups: a control group comprising rats without AP, a group called 1AP comprising rats with AP in one tooth, and a group called 4AP comprising rats with AP in four teeth. Endodontic infection was induced by pulp exposure of the first right maxillary molar in the 1AP group or by exposing the first and second right maxillary and mandibular molars in the 4AP group. A blood count and cytokine levels were obtained 30 days after infection by collecting blood by cardiac puncture. The maxillae were dissected and stained with hematoxylin and eosin to evaluate the inflammatory infiltrate. The data were tabulated and subjected to statistical analysis (P < 0.05). RESULTS: Histological analysis showed a predominance of mononuclear inflammatory cells. In blood, significant increase of leukocytes, lymphocytes, and tumor necrosis factor alpha (TNF-α) in 4AP compared with the control and 1AP groups (P < 0.05) was observed. In addition, significant decrease of interleukin-4 (IL-4) in 1AP and 4AP groups compared with the control was observed (P < 0.05). CONCLUSIONS: In the rat model, the presence of multiple AP can affect health by increasing lymphocyte and TNF-α levels in the blood. CLINICAL RELEVANCE: The presence of endodontic infections can interfere with the blood profile, altering systemic health.

Effect of photodynamic therapy on the mechanical properties and bond strength of glass-fiber posts to endodontically treated intraradicular dentin.

STATEMENT OF PROBLEM: The use of photosensitizers in photodynamic therapy promotes intraradicular microbial reduction during nonsurgical endodontic therapy. However, studies are lacking on the consequences of the application of these agents on the mechanical properties of intraradicular dentin and on the bond strength of glass-fiber posts. PURPOSE: The purpose of this in vitro study was to evaluate the influence of photodynamic therapy on the bond strength of glass-fiber posts using a push-out test and, additionally, to measure the Martens hardness (MH) and elastic indentation modulus (Eit) of intraradicular dentin when different photosensitizers are used. MATERIAL AND METHODS: Eighty bovine teeth were used to simulate experimental endodontic treatments. Biomechanical instrumentation was performed for all root canals, and the teeth were distributed into 5 groups: control-deionized water; methylene blue 50 mg/L + red laser; methylene blue 100 mg/L + red laser; curcumin 500 mg/L + blue LED; and curcumin 1000 mg/L + blue LED. The MH and Eit of intraradicular dentin were measured using an ultramicrohardness tester under a load of 3 mN (n=8). The push-out bond strength of glass-fiber posts to dentin was measured using a universal testing machine (n=8). Mechanical properties and bond strength data were subjected to the Kruskal-Wallis test, ANOVA, and Fisher least significant difference test (α=.05). Images of representative specimens were obtained using a scanning electron microscope. RESULTS: The MH, Eit, and bond strength of intraradicular dentin were influenced by the photosensitizer used. In general, curcumin promoted lower mechanical properties values but higher bond strength values. CONCLUSIONS: Photosensitizers influenced the mechanical properties of intraradicular dentin and the bond strength of glass-fiber posts, and methylene blue at 50 mg/L had no marked effect on the mechanical properties of the dentin or the bond strength values.

Traumatic periapical lesion only identified through cone beam computed tomography: a case report.

This case report describes the diagnosis of a traumatic periapical lesion, caused by parafunctional habits (bruxism) and associated with bone rarefaction, that had not been identified by periapical radiography. Slight edema was observed clinically at the apical region of the maxillary left canine; however, the tooth demonstrated only physiologic mobility, and the results of a pulpal sensitivity test were inconclusive. A cone beam computed tomogram (CBCT) showed the presence of a periapical lesion. After preparation of the root canal, intracanal medication (calcium hydroxide and paramonochlorophenol) was placed and changed once a month for 2 months. After 60 days (at the time of the second medication change), the edema at the apical region was no longer visible. The root canal was filled, and CBCTs obtained 30 days and 24 months after completion of treatment showed that the lesion had regressed with bone repair. Although it is an expensive procedure, CBCT is important in the examination and diagnosis of periapical lesions that may not be seen in periapical radiographs.

Mechanical properties of components of the bonding interface in different regions of radicular dentin surfaces.

STATEMENT OF PROBLEM: The mechanical properties of the adhesive materials used in intraradicular treatments could vary according to the interaction between the restorative material and dentin substrate. An evaluation of these properties is essential to determine the success of the luting procedures performed on glass-fiber posts. PURPOSE: The purpose of this study was to evaluate the mechanical properties of dentin adhesives, resin cements, and the dentin that underlies the bonding interface in different thirds of intraradicular dentin. MATERIAL AND METHODS: Forty extracted, single-rooted human teeth were used in this study. After the endodontic treatment of the post spaces, the teeth were divided into 5 groups (n=8): Adper Single Bond 2 + RelyX ARC, Excite DSC + RelyX ARC, Adper SE Plus + RelyX ARC, RelyX Unicem, and Set. The hardness and elastic modulus values were measured at the adhesive interface in different thirds of the radicular dentin by using an ultramicrohardness tester. The data were subjected to 2-way ANOVA and the Fisher protected least significant difference test (α=.05). RESULTS: In the underlying dentin, the highest Martens hardness values were found in the apical region for all groups; the exceptions were the groups with the self-etching adhesive. In the adhesive layer, the highest Martens hardness values were obtained for the Adper SE Plus + RelyX ARC group; further, no statistical differences were found among the different regions for this group. RelyX ARC had the lowest Martens hardness and elastic modulus values in the apical regions when used with Adper Single Bond 2 and Adper SE Plus. No differences were found in the Martens hardness and elastic modulus values for the self-adhesive resin cement in the regions investigated. CONCLUSION: The mechanical properties of adhesive materials and the underlying dentin are influenced by the interaction between the two as well as by the depth of the analyzed intraradicular area.

Influence of diabetes mellitus on tissue response to MTA and its ability to stimulate mineralization.

AIM: To evaluate the influence of diabetes mellitus on the tissue response to mineral trioxide aggregate (MTA) and its ability to stimulate mineralization. METHODS: Twenty-four male Wistar rats were divided into a non-diabetic control group and another with Alloxan-induced diabetes. Two polyethylene tubes, one kept empty as a control and the other containing Angelus MTA(®) , were implanted into the dorsal connective tissue of all rats for 30 days. Animals in each group received injections of calcein, alizarin, and oxytetracycline on day 7, 14, and 21, respectively. Animals were killed after 30 days; specimens were prepared by staining with hematoxylin and eosin (HE) and von Kossa technique as well as for examination of unstained sections with polarized light and fluorescence microscopy. RESULTS: The inflammatory reaction to the implanted tubes was equally mild in both groups. Structures staining with von Kossa were seen in response to Angelus MTA(®) , as were birefringent structures visualized on polarized light analysis; these had no relation to diabetic condition (P < 0.05). Fluorescence intensity was not changed in diabetic rats either (P < 0.05). CONCLUSION: Diabetes mellitus did not influence the tissue response to Angelus MTA(®) or the mineralization stimulated by it.

The use of NaOCl in combination with CHX produces cytotoxic product.

OBJECTIVES: The combination of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) yields a "precipitate potentially toxic" (PPT). The aim of this study was to evaluate the tissue response to implanted polyethylene tubes filled with PPT-soaked fibrin sponge. METHODS: Forty rats received four polyethylene tubes each; each tube was filled with fibrin sponge soaked by 2.5 % NaOCl, 2.0 % CHX, PPT (2.5 % NaOCl plus 2.0 % CHX), or not soaked (control). The observation time points were 7, 15, 30, 60, and 90 days. At each time point, eight animals were killed, and the tubes and surrounding tissues were removed, fixed, and prepared for light microscopic analysis by performing glycol methacrylate embedding, serial cutting into 3-µm sections, and hematoxylin-eosin staining. Qualitative and quantitative evaluations of the reactions were performed. Results were statistically analyzed by Kruskal-Wallis test (p < 0.05). RESULTS: All chemical solutions caused moderate reactions at 7 days. On day 30, PPT group was more cytotoxic than the control group and the CHX group (p < 0.05). On days 15 and 60, PPT group was more cytotoxic than the control group (p < 0.05). On day 90, there was no statistically significant difference between the different groups. CONCLUSION: PPT is more cytotoxic than NaOCl and CHX alone, particularly in the short term. CLINICAL SIGNIFICANCE: Protocols which suggest the use of CHX and NaOCl must be revised because this mixture produces cytotoxic product.

Apical periodontitis and periodontal disease increase serum IL-17 levels in normoglycemic and diabetic rats.

OBJECTIVES: This study aimed to evaluate the influence of apical periodontitis (AP) and/or periodontal disease (PD) on serum interleukin-17 (IL-17) levels in a rat model of diabetes mellitus (DM). METHODS: Eighty male Wistar rats were divided into eight groups of ten animals each: normoglycemic, AP, PD, AP+PD, DM, DM+AP, DM+PD, and DM+AP+PD. DM was induced using streptozotocin, AP by dental pulp exposure to the oral environment, and PD by periodontal ligature. The animals were sacrificed after 30 days, and venous blood samples were collected via cardiac puncture to determine the serum IL-17 and neutrophil levels. The maxillae were dissected and processed for radiographic analysis. The periapical lesion areas were quantified in pixels. The total assessed values were tabulated according to each experimental group and were statistically analyzed using Spearman's correlation and Kruskal-Wallis test (p < 0.05). RESULTS: A significant difference in the serum IL-17 levels was observed between the groups without oral infections and the groups with AP+PD-associated lesions, regardless of the presence of DM (p < 0.05). Diabetes increased the neutrophil levels, regardless of the presence of oral infection. However, a combination of two oral infections increased the neutrophil levels in DM rats (p < 0.05). The level of bone resorption lesions was greater in DM rats than in normoglycemic rats (p < 0.05). CONCLUSION: The combination of AP and PD increased the serum IL-17 levels in DM and normoglycemic rats and increased the neutrophil levels in DM rats. Diabetes increased the neutrophil levels and bone resorption in rats. CLINICAL SIGNIFICANCE: AP is capable of potentiating systemic inflammatory changes when associated with PD, and increases in blood glucose can accelerate the pathogenesis of oral infections.

Cytotoxicity, Biocompatibility, and Calcium Deposition Capacity of 45S5 Bioglass Experimental Paste and Bio-C Temp: In Vitro and In Vivo Study Using Wistar Rats.

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.