Effect of fluoride or chitosan toothpaste and at-home bleaching in enamel roughness, tooth color, and staining susceptibility.

Purpose: To evaluate how fluoride- or chitosan-based toothpaste used during at-home bleaching affects enamel roughness, tooth color, and staining susceptibility.

Methods: Bovine enamel blocks were submitted to a 14-day cycling regime considering a factorial design (bleaching agent x toothpaste, 2 x 3), with n=10: (1) bleaching with 16% carbamide peroxide (CP) or 6% hydrogen peroxide (HP), and (2) daily exposure of a fluoride (1,450 ppm F-NaF) toothpaste (FT), chitosan-based toothpaste (CBT), or distilled water (control). Then, 24 hours after the last day of bleaching procedure the samples were exposed to a coffee solution.

Comparison of conventional ceramic laminate veneers, partial laminate veneers and direct composite resin restorations in fracture strength after aging.

Objectives: The objectives of this study were to test the fracture strength in vitro of laminate veneers, partial laminate veneers and composite restorations after aging and analyze the failure mode.

Methods: Forty extracted, sound human teeth were selected and divided into four groups: 1) Control group (CG); 2) Conventional Laminate Veneer (CLV); 3) Partial Laminate Veneer (PLV); 4) Direct Composite Resin (DCR). Laminate veneer preparations with incisal overlap were made in group CLV whereas only incisal preparations were made with a 1 mm bevel in group PLV and DCR.

Antibacterial resin-based composite containing chlorhexidine for dental applications.

Objeticve: The aim of this study was to develop a composite material with antibacterial activity using MMT loaded with clorhexidine (CHX). For that it was used a BisGMA/TEGDMA matrix and added low concentration of MMT/CHX. The aim was to evaluate the drug release capacity of MMT, and not to provide reinforcement.

Utilizing the optical properties of composite resins to improve esthetics: a layering technique for anterior restorations.

A comprehensive knowledge of the optical properties of composite resins is essential to achieving optimal results in direct anterior restorations. This case report describes an anterior composite resin restoration fabricated with a layering technique and explains how to use a simple photographic method to verify that the desired optical effects are reproduced. A Class IV restoration was completed on a maxillary central incisor with the help of a silicone guide.

Extruded upper first molar intrusion: Comparison between unilateral and bilateral miniscrew anchorage.

Objective: The aim of his study was to evaluate the stress on tooth and alveolar bone caused by orthodontic intrusion forces in a supraerupted upper molar, by using a three-dimensional Finite Element Method (FEM).

Methods: A superior maxillary segment was modeled in the software SolidWorks 2010 (SolidWorks Corporation, Waltham, MA, USA) containing: cortical and cancellous bone, supraerupted first molar, periodontal tissue and orthodontic components. A finite element model has simulated intrusion forces of 4N onto a tooth, directed to different mini-screw locations.

Physical, chemical and antimicrobial evaluation of a composite material containing quaternary ammonium salt for braces cementation.

The antibiofilm effect of iodide quaternary ammonium methacryloxy silicate (IQAMS) in Transbond XT Light Cure Adhesive resin used for braces cementation was evaluated. Fourier Transform Infrared (FTIR) spectroscopy confirmed IQAMS formation and Scanning Electron Microscopy coupled to Energy-Dispersive X-ray Spectroscopy (SEM-EDS) revealed that as coating, the quaternary ammonium groups from IQAMS were homogeneously dispersed throughout the surface. When incorporated, the composite material presented homogeneous dispersion throughout the resin.