Efficacy of fluoride varnishes with different compositions on white spot lesions remineralization / Eficácia de vernizes fluoretados com diferentes composições na remineralização de manchas brancas

Objective: To evaluate the efficacy of different fluoride varnishes on white spot lesions (WSL) remineralization. Material and Methods: Polished bovine enamel specimens were obtained (n = 60) and had their initial surface Knoop microhardness (SMH) determined. WSL were created and the SMH was measured again. Then, specimens were allocated into six groups: C ­ Control (without varnish); BF ­ Bifluorid 12 (6% NaF + 6% CaF2); DP ­ Duraphat (5% NaF); PF ­ Profluorid (5% NaF); FP - Fluor Protector (0.2% NaF + 0.9% difluorsilane); CW - Clinpro White Varnish (5% NaF + 5% TCP). After varnishes application, specimens were immersed in artificial saliva for 24 h. Then, pH-cycling was performed for 8 days and SMH was measured. Data were analyzed by one-way ANOVA and Tukey's test. Results: Non-significant differences were observed among the groups at baseline (p = 0.187) and after WSL formation (p = 0.999). After treatments, significant differences were observed among the groups (p = 0.001). Mean % of alteration (SD) and results of Tukey test were: C- 92.40 (12.10)a; PF- 88.66 (10.66)a; FP- 85.90 (14.49)ab; BF- 67.85 (17.86)bc; CW- 66.60 (18.48)c; DP- 58.62 (8.69)c. Conclusion: Bifluorid 12, Clinpro White Varnish, and Duraphat showed higher efficacy than artificial saliva in promoting the remineralization of WSL, nevertheless, none of the treatments were able to recover sound enamel baseline microhardness (AU)

Objetivo: Avaliar a eficácia de diferentes vernizes fluoretados na remineralização de lesões de mancha branca (LMB). Material e métodos: Espécimes de esmalte bovino polido (n = 60) foram submetidos à análise de microdureza superficial Knoop (KMH) inicial. Foram então criadas LMB artificialmente e os espécimes foram alocados em seis grupos: C ­ Controle (sem aplicação de verniz); BF ­ Bifluorid 12 (6% NaF + 6% CaF2); DP ­ Duraphat (5% NaF); PF ­ Profluorid (5% NaF); FP - Fluor Protector (0.2% NaF + 0.9% difluorsilano); CW - Clinpro White Varnish (5% NaF + 5% TCP). Após a aplicação dos vernizes, os espécimes ficaram imersos em saliva artificial por 24h e uma ciclagem de pH foi realizada por 8 dias. Após a ciclagem, KMH final foi realizada. Os dados foram analisados por ANOVA e teste de Tukey (5%). Resultados: Não foi observada diferença significante para os grupos após a KHM inicial (p = 0.187) e após a formação de LMB (p = 0.999). Após os tratamentos, diferenças significativas foram observadas entre os grupos (p = 0.001). Valores de média de % de alteração superficial (desvio-padrão) e resultados do teste de Tukey foram: C- 92.40 (12.10)a; PF- 88.66 (10.66)a; FP- 85.90 (14.49)ab; BF- 67.85 (17.86)bc; CW- 66.60 (18.48)c; DP- 58.62 (8.69)c. Conclusão: Os vernizes Bifluorid 12, Clinpro White Varnish e Duraphat apresentaram maior eficácia na remineralização das LMB quando comparados à saliva artificial, entretanto, nenhum dos produtos testados foi capaz de recuperar os valores iniciais de microdureza. (AU)

Análise da efetividade de polimerização, adaptação marginal e interna de restaurações Classe II de resinas compostas de inserção em bloco utilizando diferentes matrizes / Effectiveness of cure, marginal and internal adaptation of Class II bulkfill composites restorations made with different matrices bands

O objetivo deste estudo foi analisar a efetividade de polimerização, a adaptação marginal e interna de resinas compostas para dentes posteriores, empregando diferentes matrizes associadas ao envelhecimento artificial. Cento e vinte incisivos bovinos foram cortados e desgastados para simular dentes posteriores, nos quais foram realizados preparados de Classe II, com o ângulo cavo superficial gengival em dentina. As cavidades tinham 6 mm de altura (ocluso-cervical), 3 de largura(vestibulo-lingual) e 1,5 de profundidade (mesio-distal). Os espécimes foram divididos em seis grupos de acordo com o material restaurador utilizado: GrandioSO (Voco)– convencional incremental, G-aenial universal flo (GC)– fluída incremental, Xtrafil (Voco)– convencional com inserção em bloco, X-tra base (Voco)– fluída com inserção em bloco, Venus Bulk Fill (Kulzer)– fluída com inserção em bloco e SureFil SDR (Dentsply)– fluída com inserção em bloco. As resinas fluídas com inserção em bloco foram inseridas em incremento de 4 mm e receberam uma cobertura oclusal de 2 mm utilizando a resina GrandioSO, com exceção da X-tra fil que foi coberta com uma camada adicional do mesmo material. Nos demais grupos foi utilizada uma técnica incremental de 2 mm. Metade dos espécimes foi restaurada com matriz metálica e a outra metade com matriz de poliéster. O percentual de polimerização foi mensurado através da dureza Knoop e da relação dureza base/topo. A média da largura das fendas marginais presentes nas margens de cada restauração foi calculada após medição, em micrometros, no microscópio óptico (100x). Os espécimes foram submetidos à ciclagem mecânica (500,000 ciclos) e térmica (1,000 ciclos) e a fenda marginal foi avaliada novamente. Para fenda interna, os espécimes foram seccionados em uma cortadeira de precisão e o comprimento, em milímetros, da parede gengival que apresentava fenda foi mensurado no microscópio óptico. Foi calculada então a porcentagem de fenda em relação ao comprimento total...

The aim of this study was to analyze the effectiveness of cure, marginal and internal adaptation of composite resins for posterior teeth using different matrices bands associated with artificial aging. One hundred and twenty bovine incisors were cut and flattened in order to simulate posterior teeth, and then were prepared for class II cavities with gingival cavosurface margin in dentin. Cavities had 6 mm height(occluso-cervical), 3 mm width (bucco-lingual) and 1.5 mm deep (mesio-distal).Specimens were divided into six groups according to the restorative material:GrandioSO (Voco)- conventional, G-aenial universal flo (GC)- flowable, X-tra fil (Voco)- conventional bulk, X-tra base (Voco)- flowable bulk, Venus Bulk Fill (Kulzer)- flowable bulk, and SureFil SDR (Dentsply)- flowable bulk. Bulk-fill composites were placed in single increment of 4mm and received a 2mm occlusal coverage of GrandioSO, with the exception of X-tra fil which was covered with a layer of the same material. The remmaing groups were restored in 2 mm incremental technique. Half ofthe specimens were restored with metallic and the other half with polyester matrix. of cure was measured by Knoop hardness and the bottom/tophardness ratio was evaluated. The average width of marginal gaps present in the restoration was calculated after optical microscope measuring (100x), in microns. The specimens were subjected to mechanical (500.000 cycles) and thermal cycling (1.000 cycles) and marginal gap was evaluated again. For internal adaptation, the specimens were sectioned and the gap length, in millimeters, present on the gingivalwall was measured in an optical microscope. The percentage of gap length in relation to the total length of the wall was also calculated. Data were analyzed with three andtwo-way ANOVA and Tukey´s test. Regarding effectiveness of cure, significant differences were observed for resin factor. Composites G-aenial universal flo (82.08%) and GrandioSO(84.62%) had the highest cure...

Análise da efetividade de polimerização, adaptação marginal e interna de restaurações Classe II de resinas compostas de inserção em bloco utilizando diferentes matrizes / Effectiveness of cure, marginal and internal adaptation of Class II bulkfill composites restorations made with different matrices bands

O objetivo deste estudo foi analisar a efetividade de polimerização, a adaptação marginal e interna de resinas compostas para dentes posteriores, empregando diferentes matrizes associadas ao envelhecimento artificial. Cento e vinte incisivos bovinos foram cortados e desgastados para simular dentes posteriores, nos quais foram realizados preparados de Classe II, com o ângulo cavo superficial gengival em dentina. As cavidades tinham 6 mm de altura (ocluso-cervical), 3 de largura(vestibulo-lingual) e 1,5 de profundidade (mesio-distal). Os espécimes foram divididos em seis grupos de acordo com o material restaurador utilizado: GrandioSO (Voco)– convencional incremental, G-aenial universal flo (GC)– fluída incremental, Xtrafil (Voco)– convencional com inserção em bloco, X-tra base (Voco)– fluída com inserção em bloco, Venus Bulk Fill (Kulzer)– fluída com inserção em bloco e SureFil SDR (Dentsply)– fluída com inserção em bloco. As resinas fluídas com inserção em bloco foram inseridas em incremento de 4 mm e receberam uma cobertura oclusal de 2 mm utilizando a resina GrandioSO, com exceção da X-tra fil que foi coberta com uma camada adicional do mesmo material. Nos demais grupos foi utilizada uma técnica incremental de 2 mm. Metade dos espécimes foi restaurada com matriz metálica e a outra metade com matriz de poliéster. O percentual de polimerização foi mensurado através da dureza Knoop e da relação dureza base/topo. A média da largura das fendas marginais presentes nas margens de cada restauração foi calculada após medição, em micrometros, no microscópio óptico (100x). Os espécimes foram submetidos à ciclagem mecânica (500,000 ciclos) e térmica (1,000 ciclos) e a fenda marginal foi avaliada novamente. Para fenda interna, os espécimes foram seccionados em uma cortadeira de precisão e o comprimento, em milímetros, da parede gengival que apresentava fenda foi mensurado no microscópio óptico. Foi calculada então a porcentagem de fenda em relação ao comprimento total ...

The aim of this study was to analyze the effectiveness of cure, marginal and internal adaptation of composite resins for posterior teeth using different matrices bands associated with artificial aging. One hundred and twenty bovine incisors were cut and flattened in order to simulate posterior teeth, and then were prepared for class II cavities with gingival cavosurface margin in dentin. Cavities had 6 mm height(occluso-cervical), 3 mm width (bucco-lingual) and 1.5 mm deep (mesio-distal).Specimens were divided into six groups according to the restorative material:GrandioSO (Voco)- conventional, G-aenial universal flo (GC)- flowable, X-tra fil (Voco)- conventional bulk, X-tra base (Voco)- flowable bulk, Venus Bulk Fill (Kulzer)- flowable bulk, and SureFil SDR (Dentsply)- flowable bulk. Bulk-fill composites were placed in single increment of 4mm and received a 2mm occlusal coverage of GrandioSO, with the exception of X-tra fil which was covered with a layer of the same material. The remmaing groups were restored in 2 mm incremental technique. Half ofthe specimens were restored with metallic and the other half with polyester matrix. of cure was measured by Knoop hardness and the bottom/tophardness ratio was evaluated. The average width of marginal gaps present in the restoration was calculated after optical microscope measuring (100x), in microns. The specimens were subjected to mechanical (500.000 cycles) and thermal cycling (1.000 cycles) and marginal gap was evaluated again. For internal adaptation, the specimens were sectioned and the gap length, in millimeters, present on the gingivalwall was measured in an optical microscope. The percentage of gap length in relation to the total length of the wall was also calculated. Data were analyzed with three andtwo-way ANOVA and Tukey´s test. Regarding effectiveness of cure, significant differences were observed for resin factor. Composites G-aenial universal flo (82.08%) and GrandioSO(84.62%) had the highest cure ...

Effects of Different Surface Treatments on Composite Repairs.

PURPOSE: To evaluate the influence of different surface treatments on roughness and bond strength of composite repairs. MATERIALS AND METHODS: 120 truncated conical specimens were prepared with composite Grandio SO (VOCO) and submitted to 5000 thermal cycles. Specimens were divided into 12 groups (n = 10) regarding the surface treatments: negative control (NC), without treatment; medium-grit diamond bur (MGD); coarse-grit diamond bur (CGD); conventional carbide bur (ConC); crosscut carbide bur (CutC); chemical vapor deposition diamond bur (CVD); sandblasting with aluminum oxide (AlO); Er:YAG laser 200 mJ/10 Hz (Er200); Er:YAG laser 60 mJ/10 Hz (Er50); Nd:YAG laser 120 mJ/15 Hz (Nd120); Nd:YAG laser 60 mJ/ 15Hz (Nd60); air abrasion with 110-µm silica modified aluminum oxide (Rocatec Plus-3M) (SIL). After the surface treatments, the surface roughness (Ra) was measured using a profilometer, and then the adhesive system Admira Bond (VOCO) was applied. Another truncated conical restoration was built up with the same composite over the bonded area of each specimen. In order to evaluate the cohesive strength, double-cone specimens were made and considered as a control group (CoheC). The specimens were submitted to tensile bond strength testing and the obtained data (MPa) were evaluated by one-way ANOVA, Tukey's and correlation tests. RESULTS: ANOVA showed significant differences among experimental groups for roughness and adhesive strength (p < 0.00). The roughness values (Ra) were: NC (0.21 ± 0.19)(c); ConC (0.30 ± 0.08)(c); CutC (0.50 ± 0.22)(cd); CVD (0.74 ± 0.14)(bd); MGD (0.89 ± 0.39)(ab); Er50 (0.89 ± 0.14)(ab); AlO (0.90 ± 0.07)(ab); Nd60 (0.94 ± 0.33ab; SIL (0.98 ± 0.07)(ab); Nd120 (1.10 ± 0.19)(a); CGD (1.10 ± 0.32)(a); Er200 (1.12 ± 0.21)(a). The results of the tensile bond strength test in MPa were: CGD (11.58 ± 3.03)(a); MGD (12.66 ± 3.82)(ab); NC (13.51 ± 3.95(ab); Nd120 (14.11 ± 5.95)(ab); ConC (14.73 ± 6.12)(ab); Er200 (15.51 ± 1.45)(abc); CVD (15.61 ± 5.00(abc); Er50 (16.44 ± 2.75) (abc); CutC (16.79 ± 2.98)(abc); Nd60 (17.72 ± 2.45)(abcd); AlO (18.33 ± 3.19)(bcd); SIL (21.13 ± 4.48(cd); CoheC (23.50 ± 5.81)(d). The groups followed by the same letters were not statistically significantly different (Tukey's test). No correlation was found between bond strength and roughness (r = 0.007). CONCLUSION: Air abrasion with silica coating (Rocatec) was the only method which resulted in significantly higher bond strength in relation to the negative control group. The increase in laser energy produced a rougher surface, but reduced the bond strength.

The effect of CPP-ACP and Nd:YAG laser on the bond strength of softened dentin.

The purpose of this study was to investigate the effect of CPP-ACP treatment and Nd:YAG laser on microtensile bond strength (µTBS) of softened dentin. Sixty samples were obtained from thirty sound third molars. All samples were submitted to dentin softening procedure, by the immersion of the specimens in 30 mL of Sprite Zero for 30 min. Afterwards, the samples were randomly divided according to the CPP-ACP treatment: CG-Control group; MP-treated with CPP-ACP paste (MI Paste); MPP-treated with CPP-ACP+900 ppm NaF paste (MI Paste Plus). Each group was further divided according to bonding procedure: NL-No laser; L-Laser irradiation after adhesive application and before polymerization. The laser parameters used were 1.4 W, 10 Hz, 140 mJ/pulse, with an optic fiber of 320 µm, generating energy of 174 J/cm(2) per pulse. All samples were restored with Clearfil SE Bond/Filtek Z350 XT. After 24 h, the restored samples were cut into beams (± 1 mm(2) adhesive interface area) and subjected to a µTBS test. Data were analyzed by two-way ANOVA test and Holm-Sidak post-hoc method (α = 0.05). The treatment with CPP-ACP pastes did not significantly affect softened dentin µTBS (p = 0.070). Statistic revealed significant reduction on µTBS values for CG/L, leading to the rejection of the second null hypothesis (p < 0.001). Both CPP-ACP based pastes did not affect µTBS of softened dentin for the adhesive system utilized. The Nd:YAG laser irradiation after application of adhesive system did affect µTBS values of softened dentin samples untreated with CPP-ACP based pastes.

The effect of CPP-ACP and Nd:YAG laser on the bond strength of softened dentin

The purpose of this study was to investigate the effect of CPP-ACP treatment and Nd:YAG laser on microtensile bond strength (µTBS) of softened dentin. Sixty samples were obtained from thirty sound third molars. All samples were submitted to dentin softening procedure, by the immersion of the specimens in 30 mL of Sprite Zero for 30min. Afterwards, the samples were randomly divided according to the CPP-ACP treatment: CG-Control group; MP-treated with CPP-ACP paste (MI Paste); MPP-treated with CPP-ACP+900 ppm NaF paste (MI Paste Plus). Each group was further divided according to bonding procedure: NL-No laser; L–Laser irradiation after adhesive application and before polymerization. The laser parameters used were 1.4 W, 10 Hz, 140 mJ/pulse, with an optic fiber of 320 µm, generating energy of 174 J/cm2 per pulse. All samples were restored with Clearfil SE Bond/Filtek Z350 XT. After 24 h, the restored samples were cut into beams (± 1 mm2adhesive interface area) and subjected to a µTBS test. Data were analyzed by two-way ANOVA test and Holm-Sidak post-hoc method (α = 0.05). The treatment with CPP-ACP pastes did not significantly affect softened dentin µTBS (p = 0.070). Statistic revealed significant reduction on µTBS values for CG/L, leading to the rejection of the second null hypothesis (p < 0.001). Both CPP-ACP based pastes did not affect µTBS of softened dentin for the adhesive system utilized. The Nd:YAG laser irradiation after application of adhesive system did affect µTBS values of softened dentin samples untreated with CPP-ACP based pastes.

A split-mouth randomized clinical trial of conventional and heavy flowable composites in class II restorations.

OBJECTIVE: The aim of this study was to evaluate the 2-year clinical performance of class II restorations made with a composite resin with two different viscosities. METHODS: 47 patients received two class II restorations (n=94), one made with GrandioSO (conventional viscosity - CV), and the other with GrandioSO Heavy Flow (flowable viscosity - FV), subjecting both materials to the same clinical conditions. The self-etching adhesive Futurabond M was used for all restorations. The composites were inserted using the incremental technique. The restorations were evaluated using the modified USPHS criteria according to the periods: baseline, 6 months, 1 year and 2 years after restorative procedures. RESULTS: After 24 months, 40 patients attended the recall and 78 restorations were evaluated. In all periods, no secondary caries was observed. After 6 months, there were slightly overall changes of scores for most parameters. After 24 months, the higher number of changes from score Alfa to Bravo was observed for marginal discolouration (32.5% - CV and 39.5% - FV) and colour match (15% - CV and 31.6% - FV), followed by proximal contact (25% - CV and 23.7% - FV) and marginal adaptation (20% - CV and 21.1% - FV). For wear, surface texture and postoperative sensitivity the changes were very small. Just two restorations were lost during the 24-month follow up. Less than 5% of all restorations showed postoperative sensitivity. Chi-square test showed no significant differences between the two materials for all parameters analysed. CONCLUSION: After 2 years of clinical service, no significant differences were observed between GrandioSO conventional and GrandioSO Heavy Flow for the parameters analysed. Both materials provided acceptable clinical behaviour in class II restorations. CLINICAL SIGNIFICANCE: This study presents the possibility of using a flowable composite with high filler content, for performing class II restorations.

Effectiveness of low level laser therapy in the treatment of TMD myalgia: two case reports / Eficácia do laser de baixa potência no tratamento da DTM: dois relatos de casos

Objective: To report two cases of low level laser therapy used in the treatment of muscle pain caused by temporomandibular disorders (TMDs). Methods: Two patients were selected and subjected to eight applications of low level laser therapy (diode - wavelength of 795 nm, energy density of 8 J/cm2, power of 120 mW, 66 se per point). Laser was punctually applie on masseter and temporalis muscles bilaterally. Three methods were used to evaluate the effectiveness of treatment: pressure algometer, visual analog scale (VAS) and maximal mouth opening. Each measurement was performed before and after the laser therapy session. The results were subjected to statistical analysis (ANOVA two factors and Tukey’s test, α = 0.05). Results: For both patients, no significant difference was found between the results obtained with the algometer, before and after laser application, within each session. VAS results showed a tendency to lower values after laser application. In both cases, the highest values obtained by the pressure algometer were found between the days 9 (fourth application) and 16 (sixth application). Both patients had an improvement on mouth opening. Conclusions: The assessment methods used were quite practical to register the pain before and after treatment. Therapy with low level laser seems to have a beneficial effect for the masticatory muscles pain.

Objetivo: relatar dois casos do uso do laser de baixo potência no tratamento da dor muscular causada pela disfunção temporomandibular (DTM). Métodos: Dois pacientes foram selecionados e submetidos a oito aplicações de laser de baixa potência (diodo - comprimento de onda de 795 nm, densidade de energia de 8 J/cm2, potência de 120 mW, 66 segundos por ponto). O laser foi aplicado pontualmente nos músculos masseter e temporal bilateralmente. Três métodos foram utilizados para avaliar a eficácia do tratamento: algômetro de pressão, escala visual analógica (VAS) e abertura máxima da boca. Cada medição foi realizada antes e após a sessão de terapia com laser. Os resultados foram submetidos à análise estatística (ANOVA dois fatores e teste de Tukey, α= 0,05). Resultados: Em ambos os casos, não foi encontrada diferença significativa entre os resultados obtidos com o algômetro antes e depois da aplicação do laser dentro de cada sessão. Os resultados com o VAS mostraram uma tendência a reduzir os valores após a aplicação do laser. Foram encontrados os maiores valores obtidos pelo algômetro de pressão entre os dias 9 (quarta aplicação) e 16 (sexta aplicativo), em ambos os casos. Ambos os pacientes tiveram uma melhora na abertura da boca. Conclusões: Os métodos de avaliação utilizados foram bastante prático para registrar a dor antes e após o tratamento. A terapia com laser de baixa potência parece ter um efeito benéfico para a dor músculos mastigatórios

Bond Strength of composite repairs using flowable, conventional resins or the association of both / Resistência de união de reparos de resinas compostas usando resinas convencionais, fluidas, ou a associação de ambas

Objectives: The aim of this in vitro study was to evaluate the effect on bond strength of composite repairs using flowable resin as an intermediate agent . Methods: Thirty truncated cones were fabricated with Grandio SO (VOCO) and were thermo-cycled for 5000 cycles for artificial aging. Specimen’s surface was sandblasted with aluminum oxide, cleaned with air/water spray and conditioned with phosphoric acid for 15 s. One coat of Admira Bond Adhesive (VOCO) was applied and light cured for 20 s. Specimens were divided into 3 groups according to the repairing material used (n = 10): Conventional Resin – Grandio SO (R), A thin layer of Flowable resin – Grandio SO Heavy Flow + conventional Resin (FR), and Flowable resin (F). Over the original specimens, a sectional cone-shaped teflon matrix was hold in position and the cones were built according the groups described above. Other thirty specimens were built, 10 of each group, simulating a restoration without repair. Specimens were submitted to tensile stress in a universal testing machine. Data were recorded in MPa and evaluated with ANOVA, Tukey´ s and non-paired “t’’ tests. Results: ANOVA showed significant differences among groups in which repair was performed (p < 0.00). The results of Tukey´ s test for those groups were: R (19.89 + 5.31)ab; F+R (14.49 + 5.59)a; F (20.91 + 3.99)b. The groups followed by the same letter did not show statistical differences. Non-paired “t” test showed that groups R and F repairs were similar to the correspondent groups simulating restoration without repair. Conclusions: The repair with conventional or flowable composite produced bond strength values similar to cohesive strength of the same materials. The use of a thin layer of flowable resin as an intermediate agent in composite repair decreased the bond strength when compared the same method for restoration.

Objetivos: O objetivo deste estudo in vitro foi avaliar o efeito sobre a resistência de união de reparos de compósitos com resina fluida como um agente intermediário. Métodos: Trinta cones truncados foram fabricados com Grandio SO (VOCO) e foram termociclados por 5.000 ciclos de envelhecimento artificial. A superfície da amostra foi jateada com óxido de alumínio, limpa com spray ar / água e condicionada com ácido fosfórico por 15 s. Uma camada de adesivo (Admira - VOCO) foi aplicada e fotopolimerizada por 20 s. As amostras foram divididas em três grupos de acordo com o material de reparo utilizado (n=10): resina convencional - Grandio SO (R), uma fina camada de resina flowable - Grandio SO Heavy Flow + Resina convencional (FR), e resina flowable (F). Sobre espécimes originais, foi adaptada uma matriz, e os cones foram construídos de acordo com os grupos descritos acima. Trinta amostras foram construídos, 10 de cada grupo, simulando uma restauração sem reparos. As amostras foram submetidas ao Teste de tração em uma máquina universal de ensaios. Os dados foram registrados em MPa e avaliados com ANOVA, Tukey e teste “t’’ não pareado. Resultados: ANOVA mostrou diferenças significativas entre os grupos em que o reparo foi realizado (p < 0,00). Os resultados do teste de Tukey para os grupos foram: R (19,89 + 5,31) ab; F + R (14,49 + 5,59) a; F (20,91 + 3,99) b. Os grupos seguidos pela mesma letra não apresentaram diferenças estatísticas. O Teste “t” não pareado de Student mostrou que as reparações dos grupos R e F foram semelhantes aos dos grupos correspondentes que simulam restauração sem reparos. Conclusões: O reparo com resina flowable ou convencional produziu níveis de resistência próximos a força coesiva dos mesmos materiais. A utilização de uma camada fina de resina fluida como um agente intermediário no reparo dos compósitos diminuiu a resistência de união, quando comparado o mesmo método para a restauração.

Avaliação da formação de fendas marginais e da microinfiltração após envelhecimento artificial, empregando adesivos auto condicionantes fotopolimerizáveis ou duais associados à resinas compostas de diferentes viscosidades / Marginal gap and microleakage evaluation after artificial aging, using light-cured or dual self-etch adhesives associated with different viscosities composite resins

O objetivo deste estudo foi avaliar a influência do tipo de resina composta com relação à viscosidade, do tipo de adesivo autocondicionante e seu modo de presa e do envelhecimento artificial, na formação de fendas marginais e microinfiltração de restaurações de resina composta. Cavidades padronizadas com 4 mm de diâmetro e 2,5 mm de profundidade foram preparadas em 240 incisivos bovinos. Eles foram divididos em 2 grupos de acordo com a viscosidade da resina composta: GC - Grandio SO (Voco - viscosidade convencional) e GF - Grandio SO Heavy Flow (Voco - baixa viscosidade), ambas com alto conteúdo de carga. Cada grupo foi dividido em seis subgrupos, de acordo com os sistemas adesivos utilizados: FM - Futura Bond M (Voco), FDCF - Futura Bond DC (Voco) - fotopolimerizado, FDCQ - Futura Bond DC (Voco) – apenas polimerização química, CS – Clearfil S3 Bond (Kuraray), CDCF – Cleafil DC (Kuraray) – fotopolimerizado e CDCQ – Clearfil DC (Kuraray) – apenas polimerização química. Metade dos espécimes foi submetida à ciclagem mecânica (300.000 ciclos) e térmica (1.000 ciclos), sendo divididos então em C – ciclados e NC – não ciclados. A maior fenda marginal presente nas margens de cada restauração foi medida em microscópio óptico, em micrometros. Para a avaliação da microinfiltração, os espécimes foram submersos em solução de nitrato de prata amoniacal 50% por 24h, lavados, colocados em revelador radiográfico por 8h sob luz fluorescente e seccionados. As interfaces foram fotografadas e a microinfiltração mensurada em milímetros. Os dados foram submetidos à ANOVA três fatores. Para fenda marginal foi encontrada diferença significativa para todos os fatores (p=0,00). Os resultados de Tukey para resina foram GC: 28,10a e GF: 40,60b; para o adesivo CDCQ: 28,67a, CDCF: 32,25b, CS: 34,12bc, FDCF: 36,10cd, FM: 36,50cd e FDCQ: 38,46d; para a ciclagem SEM: 29,05a e COM: 39,65b. Com relação à microinfiltração, também houve diferença para todos os fatores (p=0,00)...

The aim of this study was to evaluate the influence of composite viscosity, adhesive systems type of cure and artificial aging on marginal gap formation and microleakage of composite resin restorations. Cavities with 4mm in diameter and 2,5mm deep were prepared in 240 bovine incisors. Teeth were divided in two groups according to the viscosity of composite resin: GC - Grandio SO (Voco - conventional viscosity), GF - Grandio SO Heavy Flow (Voco - low viscosity), both with higher filler content. Each group was divided into 6 subgroups, according to the bonding systems: FM - Futura Bond M (Voco), FDCF - Futura Bond DC (Voco) – light cured, FDCQ - Futura Bond DC (Voco) – chemical cured only, CS – Clearfil S3 Bond (Kuraray), CDCF – Cleafil DC (Kuraray) – light cured and CDCQ – Clearfil DC (Kuraray) – chemical cured only. Half of the specimens were subjected to mechanical (300.000) and thermal cycling (1.000). So specimens were then divided into WITH and WITHOUT thermo-mechanical cycling. The biggest marginal gap for each restoration was measured in an optical microscope in microns. For microleakage evaluation, specimens were submersed in 50% ammoniacal silver nitrate for 24h, washed for 20min and placed in radiographic developer for 8h under fluorescent light. Teeth were sectioned and the interface with the deepest microleakage in millimeters was measured. Data were analyzed with three-way ANOVA and Tukey´s test. For marginal gaps significant differences were shown for all factors (p=0.000). Tukey´s test results for resin were GC: 28.10a e GF: 40.60b; for adhesive CDCQ: 28.67a, CDCF: 32.25b, CS: 34.12bc, FDCF: 36.10cd, FM: 36.50cd e FDCQ: 38.46d; and for artificial aging WITHOUT: 29.05a and WITH: 39.65b. For microleakage, there were also differences for all factors (p=0.000). The results of Tukey´s test for resin were GC: 2.68a e GF: 3.46b; for adhesive FM: 2.85a, CDCQ: 3.00ab, FDCF: 3.08ab, CDCF: 3.15b, CS: 3.16b e FDCQ: 3.19b; and for artificial aging...(AU)