Photobiomodulation Reduces Pain-Related Symptoms Without Interfering in the Efficacy of In-Office Tooth Bleaching: A Systematic Review and Meta-Analysis of Placebo-Controlled Clinical Trials.

Objective: This systematic review aimed to determine whether the use of photobiomodulation (PBM) with low-level laser therapy prevents tooth sensitivity induced by in-office tooth bleaching with hydrogen. Methods: Placebo-controlled clinical trials were included to evaluate the efficacy of PBM with low-level laser therapy in the prevention of tooth sensitivity after in-office tooth bleaching. Searches were conducted on the Medline database via PubMed, Scopus, Web of Science, EBSCO, SciELO, LILACS, Cochrane, DOSS, and Google Scholar until July 2020, and fixed-effects meta-analysis was performed for tooth sensitivity [standardized mean differences (MDs)] and color changes (MDs). Results: Five studies were included in this systematic review and meta-analysis, with a total of 288 patients, 123 patients in the PBM group and 165 patients in the placebo group. In the meta-analysis, despite high heterogeneity, PBM significantly reduced the tooth sensitivity after the first [p < 0.001; Cohen's d = -0.32, 95% confidence interval (CI) = -0.46 to -0.18], second (p < 0.001; Cohen's d = -0.30, 95% CI = -0.46 to -0.15), and third (p < 0.001; Cohen's d = -0.82, 95% CI = -1.06 to -0.58) sessions of in-office tooth bleaching, without impairing the ΔE (p = 0.300). Conclusions: The results of this systematic review and meta-analysis suggest that PBM significantly prevents pain-related symptoms after the first three weekly sessions of in-office tooth bleaching with hydrogen.

Intense orthodontic force induces the three dental pulp nitric oxide synthase isoforms and leads to orofacial discomfort in rats.

OBJECTIVE: The objective of this study was to evaluate the role of nitric oxide synthase (NOS) isoforms influence during tooth movement with different forces. SETTINGS AND SAMPLE POPULATION: 100 male Wistar rats (n = 10/group) were divided into a Sham group (animals not submitted to device installation nor Induced Toot Movement [ITM]), Negative Control Group (NCG) (animals submitted to device installation but not to ITM) and three experimental groups (F1, F2 and F3) (submitted to ITM with forces of 25, 50 and 100 gF respectively). MATERIALS AND METHODS: A daily count of biting and scratching on the vibrissae and the Grimace scale were applied. After 4 (D4) and 11 (D11) days, the molar diastema was measured, and the animals were euthanized for histological (vascular parameters) and immunohistochemistry (iNOS, eNOS and nNOS) in the dental pulp. RESULTS: On D4, there was significant movement in the F3 group (P = .001) and on D11 in F1, F2 and F3 (P < .001). The number of bites (P < .001) and scratching (P = .006) was higher in F2-F3, and F3 had higher Grimace scores (P < .001) and weight loss (P < .001). At D4, there was an increase in pulp ectasia in F2-F3 (P = .021) and a reduction in the number of vessels in F3 (P = .005). In D4 and D11, there was a significant increase in immunostaining for iNOS and eNOS in F1 (P = .025 and P < .001 respectively) and F2 (P = .007 and P < .001 respectively). At D4, F2 and F3 showed higher immunostaining for nNOS (P = .027). CONCLUSION: Thus, IDM induced inflammatory changes in the dental pulp reflecting in force-dependent pain/suffering signs.

Spontaneous Bisphosphonate-related Osteonecrosis Associated with a Tooth that Had a Necrotic Pulp: A Case Report.

This study reports the endodontic treatment performed in a patient who presented with spontaneous bone exposure in the mandible while using intravenous bisphosphonate medication (Zometa , Novartis Pharmaceuticals Co., Basel, Switzerland). A 63-year-old female patient was referred to a private dental clinic at Fortaleza, Brazil. The patient reported that one year before, she had undergone chemotherapy for the treatment of lung cancer and associated bone metastasis. Among the medications administered was the zolendronic acid, with dosage of 4 mg every 21 days. In the oral exam, the presence of extensive bone exposure was observed in the lingual region near tooth 37. The patient reported severe pain on palpation in the region; in the pulpal sensitivity test with cold stimulus, there was an absence of pain, characteristic of pulp necrosis. Radiographically, no periapical lesion was observed. Thus, endodontic treatment was performed, and instrumentation with Reciproc R25 files in the mesial root canals and R40 in the distal canal was done, alongside with abundant 2.5% sodium hypochlorite irrigation. Interappointment medication with calcium hydroxide was maintained for 15 days. In the second session, there was the spontaneous detachment of the exposed cortical bone fragment. The root canals were filled with gutta-percha and Endosequence BC Sealer cement. After two years, complete tissue repair was observed, and the patient presented with normal periapical tissues and the tooth in masticatory function. It may be concluded that a possible relationship between pulp and periapical infections and osteonecrosis exists in patients who use bisphosphonates.

Analysis of Demineralized Chemical Substances for Disinfecting Gutta-percha Cones.

INTRODUCTION: The aim of the present research was to evaluate the effectiveness of 5% malic acid, 17% EDTA and 10% citric acid solutions used to disinfect gutta-percha cones contaminated by Enterococcusfaecalis (ATCC 29212). METHODS AND MATERIALS: Two hundred and ten previously sterilized gutta-percha cones were contaminated with E. faecalis at concentration of 1.5×108 CFU/mL. The cones were immersed in 5% malic acid, 17% EDTA, 10% citric acid, 1% NaOCl and 2.5% NaOCl for 1, 5 and 10 min. Then each cone was kept in Eppendorf tubes containing BHI sterile solution at 37°C for 48 h. The presence of turbidity in BHI solution was analyzed. The results were statistically analyzed by Kruskal-Wallis test and 5% Dunn comparisons. P-value was considered statistically significant when P<0.05. RESULTS: Regardless of exposure time, 1% NaOCl and 2.5% NaOCl were the most effective agents for rapid disinfection of gutta-percha cones (P<0.001). All specimens immersed in experimental demineralized solutions presented bacterial growth (P>0.05). CONCLUSION: Demineralized solutions tested were not effective for elimination of Enterococcus faecalis on the surface of gutta-percha cones.

Micro-CT Evaluation of Gutta-Percha Removal by Two Retreatment Systems.

INTRODUCTION: The aim of the present ex vivo research was to compare the remaining filling material and the volumes of dentine removed after retreatment of curved canals with two rotary systems naming ProTaper Universal Retreatment and Mani NRT-GPR using micro-computed tomography (micro-CT). METHODS AND MATERIAL: Forty mandibular molars containing two completely separated canals, with curvature angle of 25-35° and a curvature radius <10 mm were prepared to the Mtwo instrument 35/0.04 and filled with warm gutta-percha and AH-Plus sealer. The teeth were randomly divided into 2 groups (n=20), according to the retreatment system evaluated: ProTaper Universal Retreatment (PR group) or Mani NRT-GPR (MR group). Retreatment was considered complete when the working length was reached and when smooth dentinal walls were observed, with no evidence of filling material adhered to instruments or in the irrigating solution. Preoperative and postoperative micro-CT images were obtained with an isotropic voxel size of 11.88 µm to observe the volume of residual filling material in the canals and dentine removed after retreatment. Statistical analysis was performed by Student's t-test (P<0.05). RESULTS: The mean percentage of remaining filling material was 12.96% for PR group and 24.26% for MR group (P=0.0056). The percentage of dentin removal was greater in the PR group (5.02%) than MR group (1.36%) (P=0.0028). Both systems failed to completely remove the filling material from the canals. CONCLUSION: ProTaper Universal Retreatment system was more effective than Mani NRT-GPR system regarding removal of root filling material and also removed significantly more dentine after retreatment of curved mesial root canals of mandibular molars.

Effect of different endodontic sealers and time of cementation on push-out bond strength of fiber posts.

OBJECTIVES: This study aims to evaluate the effect of different endodontic sealers (epoxy resin, eugenol, and bioceramic/calcium silicate-based) and the time of cementation (immediately or 7 days after canal obturation) on the bond strength of a fiberglass post cemented with RelyX™ ARC. MATERIAL AND METHODS: Eighty-four premolars were instrumented and divided into groups (n = 12) according to the sealer and the time of post cementation: Endofill (EN), Endosequence BC Sealer (BC), and AH Plus (AH) had immediately fiber post cementation; EN7, BC7, and AH7 had post cementation after 7 days; and control group (C) had fiber post cementation without endodontic sealer. Each post space of the root was cut into slices and submitted to push-out test. Failure mode was assessed. Two-way ANOVA, Tukey's, and Dunnett's tests were used for statistical analysis (α = 5%). RESULTS: The type of endodontic sealer (p < 0.001), the time of post cementation (p = 0.038), and the interaction sealer time (p = 0.002) had negative influence on bond strength of fiberglass posts cemented with RelyX™ ARC. AH promoted the highest bond strength mean values (21.20 MPa immediately and 15.54 MPa at 7 days). EN (9.75 MPa immediately and 13.15 MPa at 7 days) and BC (10.43 MPa immediately and 5.73 MPa at 7 days) had lower bond strength than AH, regardless the time of cementation. CONCLUSIONS: AH was the best sealer to obturate the root canal when fiberglass cementation with resin-based cement is planned. CLINICAL RELEVANCE: The correct choice of an endodontic sealer and the adequate time of post cementation may avoid post dislocation caused by low bond strength to dentin.

Micro Push-out Bond Strength and Bioactivity Analysis of a Bioceramic Root Canal Sealer.

INTRODUCTION: Bioactive endodontic sealers have been developed to improve the quality of root canal obturation. EndoSequence Bioceramic (BC) Sealer is amongst calcium silicate-based materials recently developed for permanent root canal filling. The objective of this study was to evaluate the bioactivity of BC Sealer and its micro push-out bond strength to dentin compared to AH-Plus (AH) sealer. METHODS AND MATERIALS: To perform the micro push-out test, 24 root canals of mandibular premolars were instrumented and divided into two groups (n=12). Each root was cut into 4 slices and lumens of the canals were filled with the sealers and submitted to micro push-out test. Failure mode was assessed using scanning electron microscopy (SEM). Bioactivity of BC sealer was investigated with scanning electron microscopy/energy-dispersive X-ray (SEM/EDS) and X-ray diffraction (XRD). Bioactivity assessments were reported descriptively. Bond strength data were analyzed by parametric t-test (α=5%). RESULTS: In micro push-out test AH had higher bond strength mean values (16.29 MPa) than BC sealer (9.48 MPa) (P<0.05). Both groups had low amount of adhesive failure. SEM showed the presence of a mineral precipitate after 30 days and EDS analysis showed that those precipitates have high proportion of Ca. XRD showed peaks of crystalline phases of calcium carbonate compatible with the bioactivity. CONCLUSION: BC sealer showed indications of bioactivity and lower bond strength to dentine compared to AH.

Presence of Voids after Continuous Wave of Condensation and Single-cone Obturation in Mandibular Molars: A Micro-computed Tomography Analysis.

INTRODUCTION: The objective of this study was to assess the presence of voids in mesial root canals of mandibular molar teeth obturated by using the single-cone (SC) and continuous wave of condensation (CWC) obturation techniques, and results were analyzed by using micro-computed tomography. METHODS: Twenty-four mandibular molars with fully developed roots and mesial root curvature ranging from 25° to 35° were instrumented by using Reciproc R25 files, and then they were obturated by using the SC and CWC techniques. Specimens were scanned before and after obturation for micro-computed tomography analysis (voxel size, 17.42 µm). After volumetric analysis and tridimensional reconstruction of the root canals, data were analyzed by using analysis of variance and the Tukey test. RESULTS: No significant differences were observed between the 2 techniques in terms of total percentage volume of voids: CWC = 3.91% ± 0.72%; SC = 6.52% ± 1.16% (P > .05). Only in the cervical third, CWC showed a significantly lower percentage of voids when compared with SC, namely 2.86% ± 0.94% vs 8.00% ± 1.86%, respectively (P < .05). CONCLUSIONS: The percentage volume of voids was similar in the 2 groups and was influenced by the obturation technique only in the cervical third.

La hiperdontia en región de molares / Hyperdontia in molar region

La hiperdontia constituye una de las anomalías más estudiadas de la dentición humana. Esa alteración representa la aparición de uno o más dientes en cantidades mayores de lo normal, que puede ocurrir en la mandíbula o maxila y de manera unilateral o bilateral. La etiología de los dientes supernumerarios puede ser explicada principalmente por hiperactividad de la lámina dentaria en la fase inicial. Es importante la detección precoz de dientes supernumerarios porque se ha visto una serie de complicaciones como los diastemas, que pueden causar en la cavidad bucal: retardo de la erupción o dientes impactados, posicionamiento inadecuado de dientes permanentes, desajuste oclusal y el desarrollo de quistes y tumores odontógenos. Así el diagnóstico es normalmente realizado a partir de un examen radiográfico convencional, principalmente la radiografía panorámica. Este trabajo tuvo como objetivo relatar 4 casos clínicos de pacientes con presencia de molares supernumerarios, que fueron atendidos en el Servicio de Radiología de la Escuela de Odontología de la Universidad Federal de Ceará(AU)

Hyperdontia is one of the more studied anomalies of human dentition. This alteration represents the appearance of one or more teeth in a number greater of normal, occurring in mandible or in maxilla and could be unilateral or bilateral. The etiology of supernumerary teeth may be explained mainly due to the hyperactivity of dental plate in its initial phase; its early detection is important because of there have been a series of complications that may to cause diastemata, eruption retard or impacted teeth, inappropriate positioning of permanent teeth, occlusal misalignment and the development of odontogenic cysts or tumors. Thus, the diagnosis is normally made from a conventional radiographic examination, mainly the panoramic X-ray. The objective of present paper is the present four clinical cases of patients presenting with supernumerary molars, seen in the Radiology Service during the course of stomatology of the Federal University of Ceará(AU)