Bond Strength and Surface Roughness of Two Ceramics After Metal Bracket Debonding.

Objective: The aims of this study were to compare the bond strength between metallic brackets and two different glass ceramics and to evaluate the ceramic surface roughness after different finishing protocols.

Methods: The surface roughness of lithium disilicate and resin matrix ceramic samples was measured (initial). All samples were treated with hydrofluoric acid and silane and bonded to metallic brackets with orthodontic cement adhesive.

Effect of different fabrication methods of occlusal devices on periradicular stress distribution: A photoelastic analysis.

Statement Of Problem: Investigations on the effectiveness of new methods for optimizing the fabrication of oral devices are lacking.

Purpose: The purpose of this in vitro study was to evaluate stress distribution with photoelastic analysis in the periradicular area of teeth supporting occlusal devices fabricated by 5 different processes.

Material And Methods: The occlusal devices were fabricated by vacuum thermoforming, heat-polymerized acrylic resin, chemical polymerized acrylic resin, 3-dimensional printing, and milling (computer-aided manufacturing).