and microhardness of Admira and Definite following acid conditioning. Half of the samples were either used as controls or brushed for 10 minutes using an electric teothbrush with srurry. The remaining specimens were st・ored in orthophosphorie acid with a pH of 1.9 for 24 hours and then half were brushed. The surface roughness of Admira and Definite was not significantly at'fected by storage und...

The purpose of this study was to evaluate mechanical properties of the orthodontic wires according to heat treatment environments and cooling methods. Four types of wires were heat-treated in air, argon and vacuum at 500◦C, for 6 min, and were then either cooled in the furnace or a water bath. Increases in microhardness, maximal strength, yield strength and Young’s modulus of the orthodontic wi...

Introduction: Many patients seeking orthodontic treatment already have incipient enamel lesions and should be placed under preventive treatments. The aim of this in vitro study was to evaluate the effect of CPP-ACP paste and CO2 laser irradiation on demineralized enamel microhardness and shear bond strength of orthodontic brackets. Methods: Eighty caries-free human premolars were subjected t...

BACKGROUND Different concentrations of carbamide peroxide (10 to 22 percent) have been used successfully as bleaching agents, but the adverse effects on enamel microhardness at different times are unknown. METHODS The authors analyzed seven bleaching agents and a placebo. The agents were applied on the surface of human dental fragments for eight hours per day for 42 days and stored in vials c...

Introduction: Bleaching treatments may negatively affect the surface quality of composite restorations existing in the mouth. This study sought to assess the effect of 16% and 35% carbamide peroxide on microhardness of silorane-based versus two methacrylate-based composite resins. Methods: A total of 54 discs were fabricated from FiltekP90 (P90), FiltekZ350XT(Z350) Enamel and Filtek Z250(Z25...

The purpose of this study was to evaluate the effect of toothbrushing on the surface roughness and microhardness of Admira and Definite following acid conditioning. Half of the samples were either used as controls or brushed for 10 minutes using an electric toothbrush with slurry. The remaining specimens were stored in orthophosphoric acid with a pH of 1.9 for 24 hours and then half were brushe...

Burnishing is cold working process where hard roller are being pressed against irregular surface, so that surface finish and the micro hardness increases. In this study internal roller burnishing tool is used to burnish the drilled hole. Speed, feed, and number of passes have been varied using taguchi method to examine the surface finish and microhardness. Anova analysis is carried out. Surface...

Mechanical and heat treatment affects microstructure, hardness, and residual stresses in the surface layer. Micromagnetic examination of the material can determine the correlation between the changes in microstructure or hardness and permeability and electrical conductivity of the material. With a defined analysis frequency fa and by monitoring the Barkhausen noise variations, the depth propert...