Effect of surface treatment and cement type on dentin bonding of processed resin composite.

PURPOSE: To examine the effect of surface treatment and cement type on dentin bonding of processed resin composite restorations. METHODS: Bovine incisors were sectioned to expose mid-dentin, and randomly assigned to four different groups: Group ULT, Lava Ultimate composite blocks were bonded to dentin with RelyX Ultimate; Group ULT-CJ was treated as in Group ULT but CoJet was used to treat the intaglio surface prior to bonding; Group UNC was bonded with RelyX Unicem 2; and Group UNC-CJ was treated as in Group UNC but CoJet was used to treat the intaglio surface. RelyX Unicem 2 was used as a self-adhesive resin cement, while RelyX Ultimate was used as an adhesive resin cement with Scotchbond Universal. All adhesives and resin composites were polymerized with a high-irradiance LED polymerizing light (Elipar DeepCure-S). After bonding, all specimens were kept in 100% humidity and 37°C for 7 days and then processed for microtensile bond strength (µTBS) testing (n=15). The failure mode was analyzed under SEM as cohesive, adhesive, or mixed. Data were analyzed for statistical significance using two-way ANOVA and Tukey's HSD post-hoc test (α=0.05). RESULTS: Mean µTBS values ranged from 8.83 MPa (±3.13 MPa) for UNC to 25.63 MPa (±5.94 MPa) for ULT-CJ. Means were statistically significantly higher for the adhesive cement when compared with the self-adhesive cement (P< 0.05), and, for the adhesive cement, CoJet resulted in statistically significantly higher means (P< 0.05). The number of pre-test failures was uniform across groups (n=2-4). Failures were predominantly adhesive and mixed. The adhesive resin cement RelyX Ultimate performed significantly better than the self-adhesive resin cement RelyX Unicem 2, and surface treatment with CoJet improved bond strengths of Lava Ultimate to dentin. CLINICAL SIGNIFICANCE: CoJet treatment and adhesive resin cements should be used when bonding laboratory/CAD-CAM processed resin composite restorations to dentin.

Esthetic and functional management of an ankylosed central incisor with a conservative restorative approach.

In this case report, we share a conservative and simple restorative management approach for a relatively complex esthetic situation on an adult patient with an ankylosed maxillary central incisor in infra-occlusion. A 37-year-old healthy female patient presented for a consultation with a chief complaint of an unappealing smile. The intraoral exam revealed tooth #8 (FDI 11) was in obvious and significant infra-occlusion due to altered eruption. Periapical radiographs of this area were non-contributory and all teeth responded within normal limits to pulp vitality tests. After review of several treatment options, the patient opted for a conservative restorative approach in which a partial ceramic veneer was planned for the ankylosed tooth, while composite resin was used on the contralateral central incisor to achieve a symmetric and pleasant result. CLINICAL SIGNIFICANCE: A relatively complex clinical problem was satisfactorily resolved with a very conservative option in which composite resin and a ceramic veneer were used to restore an asymmetric smile.

Dentoalveolar Evaluation of Lower Incisors by CBCT after Treatment with Herbst Appliance.

This study aimed to evaluate the effects of the Herbst appliance on the proclination and protrusion of the lower incisors, and to verify if the device causes alveolar bone loss in the anterior region of the mandible. This is a retrospective study. The sample consisted of 35 individuals. The treatment group consisted of 22 individuals (8 girls and 14 boys; initial mean age of 8.2 years) who used the Cantilever Herbst appliance for a period of 12 months. The control group consisted of 13 individuals (3 girls and 10 boys; initial mean age of 8.9 years) who received no treatment and were followed up for a period of approximately 18 months. Cone-beam computed tomography scans were performed at the beginning and at the end of the observational period. The medullary bone thickness (MT), buccal cortical bone thickness (BCT), lingual cortical bone thickness (LCT), and lower incisors proclination and protrusion were evaluated. Data were submitted to statistical analysis (ANCOVA and Student's t-test) with a significance level of 5%. There was no significant difference in MT, BCT, LCT and incisor proclination between groups. Incisor proclination increased in the treated group with no statistical significance. The treatment group showed a significant increase in the protrusion of the incisors (p = 0.02). The Herbst appliance promoted a small proclination and protrusion of the lower incisors, without relevant clinical implications. The Herbst appliance did not cause bone loss in the anterior region of the mandible during Class II treatment.

Modulated photoactivation methods--effect on marginal and internal gap formation of restorations using different restorative composites.

UNLABELLED: This study evaluated the effect of modulated photoactivation methods on gap formation of restorations using different composites. METHODS: Sixty human third molars were selected, sectioned (two fragments), and ground to expose a flat enamel area. A cavity (5 mm long x 2 mm wide x 2 mm deep--outer margins in enamel and inner margins in dentin) was prepared on the central area of flattened surface. Single bond adhesive system was applied according to manufacturer's instructions. The specimens were assigned into 12 groups (n = 10), according to the restorative composite (Filtek Z250, Herculite XRV, and Heliomolar) and the photoactivation method [continuous light (CL); soft-start (SS); pulse delay (PD); and intermittent light (IL)]. Outer margins were stained using Caries Detector, observed under stereomicroscope, and images were transferred to a computer measurement program. Then, the specimens were sectioned in slices and the internal gaps were assigned using the same method. The length of gaps was expressed as a percentage of total length of the margins. Data (internal adaptation) were submitted to ANOVA and Tukey's test. RESULTS: All restorations showed perfect seal of the enamel outer margins. Modulated photoactivation methods (SS, PD, and IL) showed a significant reduction on internal gap formation when compared with CL, regardless of the composite. Filtek Z250 showed the best internal adaptation, regardless of the photoactivation method. CONCLUSION: Modulated photoactivation methods decrease the internal gap formation of composite restorations, and should be encouraged on clinical practice.

Minimally invasive dentistry: bond strength of different sealant and filling materials to enamel.

PURPOSE: The purpose of this study was to evaluate the shear bond strength of different sealant and filling materials, used in minimally invasive dentistry, to human enamel. MATERIALS AND METHODS: Thirty-five sound extracted third molars were selected. The crowns were longitudinally sectioned, embedded in polystyrene resin, and grounded until a flat enamel surface was reached. The samples were assigned into seven groups (n = 10), according to the materials: G1-Fluoroshield; G2-Clinpro; G3-Dyract AP; G4-F2000; G5-Vitremer; G6-Fuji IX; G7-Vidrion F. All materials were applied according to the manufacturer's instructions. The samples were stored in distilled water at 37 degrees C for 24 h and submitted to a shear bonding strength test in a universal testing machine with a crosshead speed of 0.5 mm/min. The failure sites were observed in Scanning Electron Microscopy (SEM). The data were submitted to ANOVA and Tukey's tests (p < 0.05). RESULTS: The mean values (MPa) of shear bond strength were for Fluroshield (25.92 +/- 8.83), Vitremer (20.41 +/- 13.34), Dyract AP (17.08 +/- 6.38), Clinpro (12.82 +/- 8.38), F2000 (8.71 +/- 3.74), Fuji IX (7.64 +/- 2.57), and Vidrion F (4.54 +/- 2.11). Fluroshield resin sealant and Vitremer resin modified glass-ionomer showed statistically higher shear bond strength values than the conventional glass ionomer (GIC) cements. Clinpro and F2000 showed bond strength values with statistical difference only from Fluroshield. The failure mode varied among the groups. The majority of samples presented mixed failure. CONCLUSION: FluroShield and Vitremer showed better performance of shear bond strength to enamel than conventional GIC.

Dentoalveolar evaluation of lower incisors by cbct after treatment with herbst appliance

Abstract This study aimed to evaluate the effects of the Herbst appliance on the proclination and protrusion of the lower incisors, and to verify if the device causes alveolar bone loss in the anterior region of the mandible. This is a retrospective study. The sample consisted of 35 individuals. The treatment group consisted of 22 individuals (8 girls and 14 boys; initial mean age of 8.2 years) who used the Cantilever Herbst appliance for a period of 12 months. The control group consisted of 13 individuals (3 girls and 10 boys; initial mean age of 8.9 years) who received no treatment and were followed up for a period of approximately 18 months. Cone-beam computed tomography scans were performed at the beginning and at the end of the observational period. The medullary bone thickness (MT), buccal cortical bone thickness (BCT), lingual cortical bone thickness (LCT), and lower incisors proclination and protrusion were evaluated. Data were submitted to statistical analysis (ANCOVA and Student's t-test) with a significance level of 5%. There was no significant difference in MT, BCT, LCT and incisor proclination between groups. Incisor proclination increased in the treated group with no statistical significance. The treatment group showed a significant increase in the protrusion of the incisors (p = 0.02). The Herbst appliance promoted a small proclination and protrusion of the lower incisors, without relevant clinical implications. The Herbst appliance did not cause bone loss in the anterior region of the mandible during Class II treatment.

Resumo O objetivo deste estudo foi avaliar os efeitos do aparelho de Herbst na proclinação e protrusão dos incisivos inferiores, bem como verificar se o aparelho causa perda óssea alveolar na região anterior da mandíbula. Trata-se de um estudo retrospectivo. Foi utilizada uma amostra de 35 indivíduos. O grupo tratado foi formado por 22 indivíduos (8 meninas e 14 meninos; idade média inicial de 8,2 anos) que utilizaram o aparelho de Herbst com Cantilever por um período de 12 meses. O grupo controle foi composto por 13 indivíduos (3 meninas e 10 meninos; idade média inicial de 8,9 anos) que não receberam tratamento e foram acompanhados por um período de aproximadamente 18 meses. Exames de tomografia computadorizada de feixe cônico foram realizados no início e no final do período observacional. Foram avaliadas a espessura óssea medular (EM), espessura óssea cortical vestibular (ECV), espessura óssea cortical lingual (ECL), proclinação e protrusão dos incisivos inferiores. Os dados foram submetidos a análise estatística (ANCOVA e teste t de Student) com nível de significância de 5%. Não houve alteração estatisticamente significativa na EM, ECV, ECL e proclinação dos incisivos entre os grupos. Houve um aumento na proclinação dos incisivos no grupo tratado, sem significância estatística. O grupo tratado apresentou aumento significativo na protrusão dos incisivos (p=0,02). O aparelho de Herbst promoveu uma pequena proclinação e protrusão dos incisivos inferiores, sem implicações clínicas relevantes. O aparelho de Herbst não causou perda óssea na região anterior da mandíbula durante o tratamento da Classe II.