Objectives:The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35% hydrogen peroxide using different sources of activation.Material and Methods:Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12): (G1) Control - Bleaching gel without light activation, (G2) Bleaching gel + halogen light, (G3) Bleaching gel + LED, (G4) Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel. Data were analyzed statistically by the Dunnet's test, ANOVA and Tukey's test (α=0.05).Results:The mean intrapulpal temperature values (°C) in the groups were: G1: 0.617 ± 0.41; G2: 1.800 ± 0.68; G3: 0.975 ± 0.51; and G4: 4.325 ± 1.09. The mean maximum temperature variation (MTV) values were: 1.5°C (G1), 2.9°C (G2), 1.7°C (G3) and 6.9°C (G4). When comparing the experimental groups to the control group, G3 was not statistically different from G1 (p>0.05), but G2 and G4 presented significantly higher (p<0.05) intrapulpal temperatures and MTV. The three experimental groups differed significantly (p<0.05) from each other.Conclusions:The Nd:YAG laser was the activation method that presented the highest values of intrapulpal temperature variation when compared with LED and halogen light. The group activated by LED light presented the lowest values of temperature variation, which were similar to that of the control group.

<p><strong>Objective</strong>: To evaluate the effect of different irrigation solutions prior to post cementation on the resin bonding to bovine root dentine. <strong>Material</strong> <strong>and</strong> <strong>Methods</strong>: 60 bovine roots (16 mm) were prepared to 12 mm with specific drill of a double-tapered fiber post system, included in PMMA, and divided into 6 groups, considering the irrigation solutions (IS) prior to cementation: Gr1- saline solution (control), Gr2- NaOCl 0.5 %, Gr3- NaOCl 1 %, Gr4- NaOCl 2.5 %, Gr5- NaOCl 5 %, Gr6- Chlorexidine 2 % (solution). The root canals were irrigated with IS 20 ml during 10 min. Then they were rinsed with 20 ml of distilled water and dried with paper points. One fiber post was molded with polyvinylsiloxane and 60 posts made of resin cement (PRC) were obtained moments before the cementation. The root canal dentin was etched with H₂PO₃ 37 %/15 s + washing/drying, a multi-bottle etch&amp;rinse adhesive system was applied and the PRC were resin luted with dual resin cement (DuolinkTM, Bisco). Each specimen was cut into 4 slices of ±1.8mm in thickness and submitted to push-out test (1 mm/min). <strong>Results</strong>: ANOVA showed that bond strength was significantly affected by IS (P&lt;0.0001). The highest bond strengths (MPa) were those for the groups 4 (3.51 ± 1.52) and 5 (3.0 ± 1.16). The groups 1 (0.70 ± 0.30), 2 (0.80 ± 0.24), 3 (1.26 ± 0.57) and 6 (0.90 ± 0.41) were statistically similar to each other. <strong>Conclusion</strong>: The resin bonding to the root dentine was higher when higher concentrations of hypochlorite solutions were used.</p><p><strong>Keywords</strong></p><p>Bond strength; Irrigation solutions; Push-out test; Resin cement; Root canal dentin.</p>

PURPOSE This study evaluated the effect of air abrasion and polishing regimens on the flexural strength of yttrium stabilized polycrystalline tetragonal zirconia (Y-TZP). METHODS From Y-TZP blocks (InCeram 2000 YZ Cubes; Vita Zahnfabrik, Bad Säckingen, Germany) 120 bars (25 mm × 4 mm × 1.2 mm) were obtained according to ISO 6872:2008 and randomly divided into 4 groups: Group C: (control) without surface treatment (n = 30); Group APA: Air abrasion with aluminum oxide (44 µm) (n = 30); Group SC: Silica-coating (CoJet, 30 µm) (n = 30); Group FD: Fine diamond bur (n = 30). Subsequently, all specimens were subjected to 4-point bending test (in distilled water at 37°C) in a universal testing machine (EMIC DL 1000; São José dos Pinhais, Paraná, Brazil); cross-head speed: 0.5 mm/min). The characteristic strength (0) of each specimen was obtained from the flexural strength test and evaluated using Weibull analysis. X-ray diffraction analysis was utilized to quantity the monoclinic phase. The surface topography of specimens was analyzed using 3D optical profilometer and scanning electron microscopy (SEM) after surface conditioning methods. The flexural strength data (4p) were statistically analyzed by 1-way ANOVA, Tukey test ( = 0.05) and Weibull (m = modulus, 0 = characteristic strength) were calculated. RESULTS The mean ± standard deviations (MPa) of the groups were as follows: C: 1196.2 ± 284.2a; APA: 1369.7 ± 272.3a; SC: 1207.1 ± 229.7a and FD: 874.4 ± 365.4b. The values (m) and (0) were as follows: C: 4.5 and 1308.12; APA: 5.9 and 1477.88; SC: 6.0 and 1300.28; and FD: 2.6 and 985.901, respectively. CONCLUSIONS Air particle abrasion with neither silica nor alumina showed significant difference compared to the control group but grinding with fine diamond bur impaired the flexural strength of the zirconia tested. The characteristic strength (σ 0 ) of each specimen was obtained from the flexural strength test and evaluated using Weibull analysis. X-ray diffraction analysis was utilized to quantity the monoclinic phase.The surface topography of specimens was analyzed using 3D optical profilometer and scanning electron microscopy after surface conditioning methods. were as follows: C: 4.5 and 1308.12; APA: 5.9 and 1477.88; SC: 6.0 and 1300.28; and FD: 2.6 and 985.901, respectively. Conclusions: Air particle abrasion with neither silica nor alumina showed significant difference compared to the control group but grinding with fine diamond bur impaired the flexural strength of the zirconia tested.

Objetivo: Este estudo propôs avaliar a microdureza de diferentes resinas compostas de uso direto (rcd) e indireto (rci).Materiais e Métodos: Com o auxílio de uma matriz metálica (diâmetro: 5,0mm; espessura: 2,0mm) foram confeccionadas 70 amostras, sendo (n=10) três resinas de uso direto: Gr1- Z250(3M ESPE/EUA), Gr2- W3D(Wilcos/Brasil) e Gr3- Esthetic X(Dentisply/EUA); e quatro de uso indireto: Gr4- Resilab Master (Wilcos/Brasil), Gr5- Vita VM LC (Vita Zahnfabrik/Alemanha), Gr6- Vita Zeta (Vita Zahnfabrik/Alemanha) e Gr7- Sinfony (3M ESPE/EUA). As amostras das rcd foram confeccionadas utilizando a técnica incremental, onde cada incremento de resina foi fotopolimerizado durante 40 segundos. Já as amostras da rci foram polimerizadas segundo recomendações dos fabricantes. Todos os espécimes foram armazenados em água destilada a 37ºC durante 24 horas. O teste de microdureza foi realizado em microdurômetro digital (Future-Tech, Modelo FM 700), com carga de 50 kgf por 15 segundos. Os dados obtidos (Kgf/mm2) foram analisados utilizando o teste não paramétrico de Kruskal-Wallis e o de comparação múltipla de Dunn (p<0.05). Resultados: As medidas resumo-numéricas de microdureza obtidas foram (mediana; média ± desvio padrão): Gr1 (100,12; 101,07± 5,99 Kgf/mm2), Gr2 (83,55; 84,20±5,07 Kgf/mm2), Gr3 (73,98; 73,95± 6,55 Kgf/mm2), Gr4 (52,50; 52,54± 5,9 Kgf/mm2), Gr5 (33,25; 34,36± 2,29 Kgf/mm2), Gr6 (29,60; 29.68± 1.52 Kgf/mm2), Gr7 (25,39; 25.13± 2.08 Kgf/mm2). Verificou-se que os valores de microdureza das rcd analisadas não diferiram estatisticamente entre si (p<0,05). O mesmo não se pode estabelecer para as resinas indiretas, pois a Sinfony diferiu da Resilab (p<0,05). Conclusão: Baseado nos resultados pôde-se concluir que apenas a resina composta direta Z250 apresentou valores de microdureza Vickers superior às demais resinas indiretas