Abstract Automotive windshield represents a large volume of solid waste due to limited recycling. Glass-ceramics were produced from discarded windshields with Nb2O5 as a nucleating agent at concentrations of 0, 5, 10, and 15 wt% at 700 and 800 °C sintering temperatures. Mechanical and electrical characterizations of glass-ceramics were performed. Equibiaxial flexural strength was performed and related to porosity. At 700 °C, Nb2O5 favors the monoclinic NaNbO3 phase with perovskite structure. At 800 °C, high Nb2O5 content formed crystalline phases of perovskite and quartz. Dielectric constant and electrical conductivity increased with the addition of Nb2O5, reaching 64 and 4.3 μS/m for 15 wt% Nb2O5 at 700oC. At 800oC, niobium pentoxide reduces the biaxial flexural strength from 28.7 to 14.4 MPa; while increasing the electrical conductivity from 0.10 to 0.33 µS/m for samples with 0 and 15 wt%.

Resumo Introdução A gengivite é uma inflamação gengival que geralmente pode ser tratada com higiene oral, como escovação, uso do fio dental e um anti-séptico bucal. Objetivo O objetivo deste ensaio clínico randomizado foi avaliar clinicamente a eficácia da solução de clorexidina 0,12% (CHX) como um agente antiinflamatório e na redução da presença de placa e inflamação em adultos jovens. Material e método Trinta pacientes com gengivite com idade entre 18 e 30 anos com profundidade de sondagem ≤ 3 mm com mínimo de 20 dentes em toda a boca foram selecionados e avaliados no início do estudo e 30 dias após o tratamento. Foram verificados os parâmetros clínicos periodontais: índice de placa (IP), índice gengival (GI), Índice de Higiene Oral Simplificado (IHO-S), Índice de Debris Simplificado (DI-S) e Índice de Cálculo Simplificado (IC-S). A seguir, os pacientes foram alocados aleatoriamente em dois grupos: Grupo CHX, recebeu clorexidina 0,12% previamente identificada como solução 1 e grupo placebo, recebeu solução salina identificada como solução 2. Ambos os grupos foram incluídos em programa de higiene e receberam enxaguatório bucal. Resultado Diferença estatisticamente significante entre os grupos CHX e Placebo foi observada para as variáveis PI, GI, DI-S, CI-S e OHI-S (p <0,05 - Teste T Pareado) após 30 dias. O grupo CHX melhorou a resposta ao GI em comparação ao placebo em 30 dias. Clorexidina 0,12% foi eficiente no controle da inflamação do periodonto. Conclusão Pode-se concluir que a eficácia da clorexidina como enxaguatório bucal na melhora dos índices periodontais foi confirmada em adultos jovens, mas ainda é controverso que a idade pode influenciar o IG e IHO-S.

Abstract Introduction Gingivitis is a gingival inflammation which can often be treated with oral hygiene such as brushing, flossing, and an antiseptic mouthwash. Objective The aim of this randomized clinical trial was to clinically evaluate the effectiveness of 0.12% chlorhexidine (CHX) solution as an anti-inflammatory agent and for reducing the presence of plaque and inflammation in young adults. Material and method Thirty patients with gingivitis aged 18 to 30 years with a probing depth ≤ 3 mm and a minimum of 20 teeth in the whole mouth were selected and evaluated at baseline and 30 days after treatment. Periodontal clinical parameters were verified: plaque index (PI), gingival index (GI), Simplified Oral Hygiene Index (OHI-S), Simplified Debris Index (DI-S), and Simplified Calculus Index (CI-S) Patients were then randomly allocated into two groups: CHX Group, received chlorhexidine 0.12% labeled as solution 1, and Placebo Group, received saline solution labeled as solution 2. Both groups were included in a hygiene program and received mouthwash. Result Statistically significant differences between CHX and Placebo groups were observed for the variables PI, GI, DI-S, CI-S, and OHI-S (p<0.05 - Paired T Test) after 30 days. The CHX group presented improved GI compared to Placebo at 30 days. Chlorhexidine 0.12% was efficient in the control of periodontium inflammation. Conclusion It can be concluded that chlorhexidine as a mouthwash is efficient in improving periodontal indices in young adults, but it is still controversial whether age can influence GI and OHI-S.

This study evaluated the effect of specimens' design and manufacturing process on microtensile bond strength, internal stress distributions (Finite Element Analysis - FEA) and specimens' integrity by means of Scanning Electron Microscopy (SEM) and Laser Scanning Confocal Microscopy (LCM). Excite was applied to flat enamel surface and a resin composite build-ups were made incrementally with 1-mm increments of Tetric Ceram. Teeth were cut using a diamond disc or a diamond wire, obtaining 0.8 mm² stick-shaped specimens, or were shaped with a Micro Specimen Former, obtaining dumbbell-shaped specimens (n = 10). Samples were randomly selected for SEM and LCM analysis. Remaining samples underwent microtensile test, and results were analyzed with ANOVA and Tukey test. FEA dumbbell-shaped model resulted in a more homogeneous stress distribution. Nonetheless, they failed under lower bond strengths (21.83 ± 5.44 MPa)c than stick-shaped specimens (sectioned with wire: 42.93 ± 4.77 MPaª; sectioned with disc: 36.62 ± 3.63 MPa b), due to geometric irregularities related to manufacturing process, as noted in microscopic analyzes. It could be concluded that stick-shaped, nontrimmed specimens, sectioned with diamond wire, are preferred for enamel specimens as they can be prepared in a less destructive, easier, and more precise way.

The aim of this study was to evaluate the stress distribution in the cervical region of a sound upper central incisor in two clinical situations, standard and maximum masticatory forces, by means of a 3D model with the highest possible level of fidelity to the anatomic dimensions. Two models with 331,887 linear tetrahedral elements that represent a sound upper central incisor with periodontal ligament, cortical and trabecular bones were loaded at 45º in relation to the tooth's long axis. All structures were considered to be homogeneous and isotropic, with the exception of the enamel (anisotropic). A standard masticatory force (100 N) was simulated on one of the models, while on the other one a maximum masticatory force was simulated (235.9 N). The software used were: PATRAN for pre- and post-processing and Nastran for processing. In the cementoenamel junction area, tensile forces reached 14.7 MPa in the 100 N model, and 40.2 MPa in the 235.9 N model, exceeding the enamel's tensile strength (16.7 MPa). The fact that the stress concentration in the amelodentinal junction exceeded the enamel's tensile strength under simulated conditions of maximum masticatory force suggests the possibility of the occurrence of non-carious cervical lesions such as abfractions.