although esthetic is a relative issue, depending upon the country and culture, almost all around the world, there is a consensus that a beautiful set of teeth is the one which is white and bright and is aligned regularly. in iran also the main feature of a beautiful tooth is its whiteness. during the past decades and centuries, tooth discoloration was considered as an esthetic issue and differe...

OBJECTIVES The aim of this study was to evaluate the effects of chemical activation of hydrogen peroxide (HP) gel on colour changes and penetration through the tooth structure. METHODS One hundred and four bovine incisors were used. One dentine (CD) disc and one enamel-dentine (ED) disc were prepared from each tooth. They were positioned over artificial pulpal chambers and the bleaching was p...

A number of "high power" in-office bleaching products have recently been re-introduced into the market. The use of such strong oxidizing agents has raised questions as to possible adverse effects on tooth structure and restorative materials. This study evaluated the effects of 35% carbamide peroxide (Opalescence Quick) and 35% hydrogen peroxide (Opalescence Xtra) on the surface finish of four t...

OBJECTIVES There is still some controversy in the dental literature whether carbamide peroxide bleaching causes demineralization of teeth. One of the reasons for this controversy is that there is as yet no reliable, non-destructive in vitro method for assessing mineral loss in bleached teeth. The objective of this study was to investigate the possible demineralization effect of 10% carbamide pe...

This study evaluated the effects of 10% alphatocopherol on the fracture resistance of endodontically treated teeth subjected to tooth bleaching with hydrogen peroxide and immediately restored with composite resin. Fifty bovine incisors were selected, including 10 sound teeth that constituted the control group (G1 (C)). The remaining 40 teeth, which were endodontically treated, were divided into...

OBJECTIVES Bleaching of vital teeth performed at home by the patient under the dentist's supervision, using low-concentration peroxides and custom-fitted trays specifically designed for this purpose, is one of several options for this type of dental treatment, whether alone or in combination with another in-office bleaching technique. The objective of this study is to analyse the effect on the ...

INTRODUCTION Common clinical experience suggests that tooth whitening agents are 100% effective. This study uses meta-analysis of data from published randomized controlled clinical trials to determine the efficacy of tooth whitening agents. METHODS A MEDLINE search strategy was developed and implemented to systematically identify clinical trials on dentist-prescribed, home-applied tooth white...

There are concerns that tooth bleaching agents may adversely affect dental materials. The aim of this study was to test the hypothesis that increasing concentrations of hydrogen peroxide (HP) are more effective than water at increasing metal ion release from two typical dental casting alloys during bleaching. Discs (n = 28 for each alloy) were prepared by casting and heat treated to simulate a ...

This clinical trial compared the effects of hydrogen peroxide concentration and toothbrushing on clinical response to vital bleaching. Tooth bleaching was accomplished with a flexible, polyethylene strip coated with a hydrogen peroxide bleaching gel worn for 30 minutes twice daily over a 14-day period. A total of 36 subjects were randomized to 1 of 3 treatment groups: 5.3% hydrogen peroxide str...

INTRODUCTION The aim of this study was to evaluate the effects of bleaching gel using 35% hydrogen peroxide (HP), associated with red carmine pigment (RC), in the 3:1 or 1:1 ratio, on fracture resistance and dentin microhardness of endodontically treated teeth. MATERIALS AND METHODS A total of 40 lower incisors were endodontically treated and divided into four groups (n = 10), according to th...