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Objective: This study was aimed at comparing the bleaching efficacy and bleaching sensitivity (BS) of two higher‐concentration in‐office bleaching gels (37% carbamide peroxide [CP] and 38% hydrogen peroxide [HP]) applied under two conditions: alone or in association with sonic activation. Methods: Fifty‐six volunteers were randomly assigned in the split‐mouth design into the following groups: CP, CP with sonic activation (CPS), HP, and HP with sonic activation (HPS). Two in‐office bleaching sessions were performed. Color was evaluated using Vita Classical, Vita Bleachedguide, and digital spectrophotometer at baseline and at 30 days post‐bleaching. Absolute risk and intensity of BS were recorded using two pain scales. All data were evaluated statistically (color changes [t test], BS [Chi‐square and McNemar test], and BS intensity [VAS; t test; NRS; Wilcoxon; α = 0.05]). Results: Significant and higher whitening was observed for HP when compared with CP (p < 0.04). However, higher BS intensity was observed in the former (p < 0.001). No significant difference was observed in whitening effect or BS when the HP or CP bleaching gels were agitated (sonic application) compared with when they were not (p > 0.05). Conclusion: The 37% CP gel demonstrated lower bleaching efficacy and lower BS compared with the 38% HP bleaching gel. The whitening effect was not influenced by the use of sonic activation. Clinical significance: The use of 37% CP gel did not achieve the same whitening effect when compared to 38% HP gel used for in‐office bleaching. The use of sonic activation offers no benefit for in‐office bleaching. [ABSTRACT FROM AUTHOR]

Enamel white spot lesions in anterior teeth that compromise esthetics are common. Microabrasion is indicated, since it affects enamel superficially. An acid-abrasive slurry with 37% phosphoric acid with pumice was used on the enamel for a controlled time period. Home bleaching with hydrogen peroxide was then used, further improving the final result. The method is safe, easy, and conservative and provides good esthetic results. [ABSTRACT FROM AUTHOR]

Objective: This single-blind, parallel, randomized clinical trial evaluated the genotoxic potential and effectiveness of 10% hydrogen peroxide (HP) in patients submitted to at-home bleaching. Materials and methods: Sixty young volunteers with maxillary incisors equal to or darker than M1.5 were included in the study. Patients were submitted to bleaching for 14 days (30 min/day) with one of the three 10% HP treatments: the bleaching agent was delivered in a bleaching tray (White Class, FGM), whitening strips (White Strips, Oral-b), or in prefilled disposable trays (Opalescence Go, Ultradent). The color change was evaluated with the Vita Bleachedguide, and the micronucleus test of exfoliative oral mucosa was carried out, starting from a count of 1000 cells, at the baseline, immediately after and 30 days after the end of the treatment. The micronucleus data were evaluated with the Kruskal-Wallis and Wilcoxon tests and color change with the two-way ANOVA test and the Tukey test (α = 0.05). Results: Significant whitening was observed for all groups after 14 days (p = 0.001) and was maintained after 30 days, with no difference between groups (p = 0.42). The micronucleus count did not indicate genotoxic potential in any of the groups studied (p = 0.32), irrespective of the time intervals (p = 0.62). Conclusion: No genotoxic effects of 10% HP were observed in patients submitted to at-home bleaching systems (30 min/day for 14 days), even 30 days after the end of treatment. Clinical significance: It is safe to use different systems to deliver 10% HP during at-home bleaching according to the manufacturers' recommendations, with no risk of genotoxic effects applied. [ABSTRACT FROM AUTHOR]

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Posts are used to keep the definitive restoration in place and protect the remaining dental structure, increasing its longevity. The objective of this study was to compare the tensile strength between glass fiber reinforced-posts (Ângelus) and cast posts (Ni-Cr) cemented with resin cement. Thirty single rooted human teeth had their root canal prepared with a standadized diameter and depth. The teeth were divided into three groups with ten teeth each: G1 -- cast posts; G2 -- one glass fiber reinforced post; G3 -- one glass fiber reinforced posts and two accessory glass fiber posts. Dual cured resin cement Rely X ARC 3M/ESPE was used in all groups for cementation of posts. After storage in saline for one week at 37° C, the specimens were submitted to a tensile load test in a universal testing machine (EMIC) at a crosshead speed of 0.5mm/min. The results were analyzed by the ANOVA test. Results were: G1 -- 38.377 (± 9.75); G2 -- 34.52 (± 13.39); G3 -- 38.92 (± 13.03). There was no statistically significant difference among the study groups. The conclusion was that the cast post and the glass fiber-reinforced post associated or not to accessory posts presented similar tensile strength values when cemented with resin cement. [ABSTRACT FROM AUTHOR]

Purpose: To compare the mechanical behavior (stress load dissipation and/or concentration) of posterior crowns made from Lava Ultimate (LU; 3M ESPE) and IPS e.max CAD (LD; Ivoclar Vivadent) using finite element analysis (FEA)., Materials and Methods: A 3D model of a mandibular first molar was prepared by reducing the occlusal surface by 1 or 2 mm (according to group), the axial walls by 1.5 mm, and using a 0.8-mm-deep shoulder margin as a finish line. A convergence of 6 degrees between opposing walls was set. Subsequently, four 3D crown models were created according to two test groups with two different occlusal thicknesses: (1) LD with 1.0 mm (LD1); (2) LD with 2.0 mm (LD2); (3) LU with 1.0 mm (LU1); and (4) LU with 2.0 mm (LU2). FEA models were constructed using the software Femap (Siemens). A load of 200 N was applied in the axial and oblique (20 degrees) directions for each group, and stress dissipation was viewed using the NEi Nastran software., Results: FEA results demonstrated that the LU crowns dissipated the occlusal load to the tooth structure, whereas the LD material concentrated the load inside the crowns. For the LU material, the lower the occlusal thickness, the higher the stress concentration inside the crown became, and the 2.0-mm occlusal thickness transferred lower stress to the tooth structure. The oblique, rather than the vertical, load caused an increase in the maximum stress concentration at the shoulder margin and axial walls., Conclusion: The higher the Young's Modulus mismatch between the crown material and substrate, the higher the load stress concentration inside the material became. The 2-mm occlusal thickness acted by decreasing the load stress to the tooth substrate. Finally, the axial load delivered more favorable stress transmission to the tooth substrate. The crown material and the occlusal thickness appear to be two factors that affect the mechanical behavior of stress dissipation to the tooth structure.

This study evaluated the influence of different combinations of 3 final endodontic irrigation techniques (positive-pressure irrigation [PPI], passive ultrasonic irrigation [PUI], and continuous ultrasonic irrigation [CUI]) and 2 irrigants (5.25% sodium hypochlorite [NaOCl] and 2% chlorhexidine [CHX]) on the push-out resistance of glass fiber posts. Ninety bovine roots were prepared and divided into 6 groups (n = 15): PPIN, PPI with 5.25% NaOCl; PUIN, PUI with 5.25% NaOCl; CUIN, CUI with 5.25% NaOCl; PPIC, PPI with 2% CHX; PUIC, PUI with 2% CHX; and CUIC, CUI with 2% CHX. In the PPI groups, a 30-gauge needle was used to deliver the irrigating solution. In the PUI groups, a 30-gauge needle was used to deliver the irrigating solution, which was activated for 10 seconds by means of a stainless steel file mounted on an ultrasonic unit. In the CUI groups, delivery and continuous agitation of the irrigating solution for 10 seconds were performed using a stainless steel file mounted on the ultrasonic unit. After canal preparation was completed, glass fiber posts were cemented with a dual-cure resin cement. The roots were sectioned into 1-mm-thick slices (coronal, middle, and apical thirds). After 7 days' storage in distilled water, the slices were submitted to a push-out test. The mean bond strength values were compared using 2-way analysis of variance and Tukey post hoc test (P < 0.05). The mean (SD) overall bond strength values of the specimens were as follows: PPIN, 4.46 (1.43) MPa; PUIN, 6.13 (2.35) MPa; CUIN, 7.41 (1.83) MPa; PPIC, 3.59 (1.70) MPa; PUIC, 5.49 (1.41) MPa; and CUIC, 6.0 (1.63) MPa. Irrespective of the irrigating solution, continuous ultrasonic irrigation achieved significantly greater push-out bond strengths for glass fiber posts, mainly at the apical third of the root specimens (P < 0.05)., Competing Interests: The authors report no conflict of interest pertaining to any of the products or companies discussed in this article.

Enamel alterations, such as amelogenesis imperfecta, can compromise the harmony of the smile and the patient's self-esteem and may cause tooth sensitivity. A simple and effective treatment approach uses the natural stratification of composite resins to mask deficient enamel formation and mimic the natural appearance of the substrate. The operative steps and principles for restorative success are described in this case report with 36-month follow-up.

The dental morphology usually determines the shape and volume of the interdental space, which must be filled by a dense connective tissue covered by oral epithelium to achieve pleasant esthetics. When composite resin restorations are placed to solve esthetic problems, the restorative procedure must be designed to allow the formation of healthy interdental papilla. This case report discusses aspects that should be considered when composite resin restorations are proposed for diastema closure. A 23-year-old man sought treatment for variations of space in the anterior dentition after orthodontic treatment. Direct composite resin restorations were placed in a way that respected the emergence profile, even though "black triangles" were evident immediately after the procedure. At the 45-day follow-up, complete closure of the interdental spaces by healthy papillae was observed. The emergence profile should be identified and respected when restorations are placed to obtain diastema closure because healthy periodontal tissues and acceptable esthetics depend on it.

The aim of this case report is to report esthetic rehabilitation with combined tooth bleaching, enamel microabrasion, and anterior restoration replacement in a 26-year-old man. Clinical examination showed deficient restorations in the maxillary anterior teeth, significant discoloration of the maxillary left central incisor, and hypoplastic stains affecting the maxillary right lateral incisor. A radiograph of the left central incisor showed satisfactory endodontic treatment, allowing preparation for the walking bleach technique. For 3 weeks, 37% carbamide peroxide in the pulp chamber was renewed every week. In-office bleaching with 35% hydrogen peroxide was also performed on the maxillary teeth. After 21 days, all teeth had been bleached to shade A1. After bleaching was completed, enamel microabrasion of the maxillary right lateral incisor was conducted with 6% hydrochloric acid. In later sessions, microhybrid composite resin restorations were placed in all 4 maxillary incisors. A combination of dental bleaching techniques, enamel microabrasion, and resin restorations was a successful and conservative choice for reestablishing the natural appearance of discolored teeth, improving the self-esteem of the patient.

The available options for restoring multiple surface cavities are: amalgam, composite resin, or indirect restorations. Adhesive system and intradentinal pin-retained composite resin restorations should have a similar performance to pin-retained amalgam, regarding resistance to support occlusal forces. Polymerization shrinkage is a major concern when performing direct posterior composite resin restorations and the incremental insertion technique can provide less stress and outstanding margin behavior. Intradentinal pins can potentially enhance composite resin's retention, while reducing gaps caused by polymerization shrinkage. This article reports a clinical case involving an extensive restoration on a posterior tooth with cusp loss that was successfully treated using an intradentinal pin and direct nano-hybrid composite resin restoration.

This in vitro study evaluated the tensile bond strength of glass fiber posts (Reforpost - Angelus-Brazil) cemented to root dentin with a resin cement (RelyX ARC - 3M/ESPE) associated with two different adhesive systems (Adper Single Bond - 3M/ESPE and Adper Scotchbond Multi Purpose (MP) Plus - 3M/ESPE), using the pull-out test. Twenty single-rooted human teeth with standardized root canals were randomly assigned to 2 groups (n=10): G1- etching with 37% phosphoric acid gel (3M/ESPE) + Adper Single Bond + #1 post (Reforpost - Angelus) + four #1 accessory posts (Reforpin - Angelus) + resin cement; G2- etching with 37% phosphoric acid gel + Adper Scotchbond MP Plus + #1 post + four #1 accessory posts + resin cement. The specimens were stored in distilled water at 37 degrees C for 7 days and submitted to the pull-out test in a universal testing machine (EMIC) at a crosshead speed of 0.5 mm/min. The mean values of bond strength (kgf) and standard deviation were: G1- 29.163 +/- 7.123; G2- 37.752 +/-13.054. Statistical analysis (Student's t-test; a=0.05 showed no statistically significant difference (p<0.05) between the groups. Adhesive bonding failures between resin cement and root canal dentin surface were observed in both groups, with non-polymerized resin cement in the apical portion of the post space when Single Bond was used (G1). The type of adhesive system employed on the fiber post cementation did not influence the pull-out bond strength.