Duration of tooth color change after bleaching

Article Abstract:

Teeth can be bleached or whitened by several procedures, but few studies have objectively measured the extent of whitening so produced. To learn more about this issue, the effectiveness of a single in-office bleaching treatment was evaluated in a randomized, controlled study. Ten subjects without histories of bleaching were randomly assigned to an active bleaching group and 10 more, to a mock bleaching (control) group. Prior to treatment, each of the six front teeth was evaluated for its color by a colorimeter (device that measures color intensity). The teeth were bleached with phosphoric acid, hydrogen peroxide, and exposure to light. Neither the experimenters nor the subjects knew whether the bleaching solutions were active or mock. Colorimetric readings were obtained again 15 minutes after tooth polishing. Three months later, patients compared the procedure with other dental procedures they had undergone and estimated the length of time bleaching had lasted. After the nine-month follow-up appointment, patients' teeth were again evaluated and the color compared with the initial values. Results showed that 70 percent of the active-bleaching group patients noticed a marked whitening after treatment, 20 percent noticed a slight whitening, and 10 percent noted no whitening. Conversely, 80 percent of the control group noticed no whitening, 20 percent noticed a slight effect, and none saw a marked change. Bleaching increased tooth lightness, reduced yellowishness, and did not affect blue/green or red/purple tones immediately afterwards, but much of the effect had vanished one week later. By six to nine months, lightness was increased by only 14 percent and yellowishness was improved by 28 percent. A slight effect was found for the control group, which disappeared after one week. The procedure was generally well tolerated and required about one hour to complete. The single in-office procedure led to a color change that could still be detected six to nine months later; whether the magnitude of the change is acceptable to patients, however, has not been determined. Nine of the 10 active-bleaching group subjects could no longer detect the effects of bleaching at that time. (Consumer Summary produced by Reliance Medical Information, Inc.)

Care and treatment, Methods, Oral hygiene products, Dentifrices, Color in dentistry, Mottled enamel

---

Evaluating tooth color change from carbamide peroxide gel

Article Abstract:

Carbamide peroxide gel is effective in temporarily whitening teeth. A 10% carbamide peroxide solution is commonly used as a treatment for oral infections. This treatment lasts only for minutes. When used as a whitening agent however, manufacturers recommend that carbamide peroxide gel be applied for eight hours. The safety and efficacy of this treatment was evaluated by treating 20 dental students with either a placebo or carbamide peroxide gel for five nights. The gel was held in place overnight by a fitted carrier. End-of-treatment comparisons with initial color measurements indicated that tooth lightening did occur, though some teeth responded more than others. One week after treatment, some reversal of lightening occurred though this lower level of whitening continued throughout the three month study period. The only adverse side effects were some instances of increased tooth sensitivity which resolved after completion of treatment.

Dentistry

---

The effects of seven carbamide peroxide bleaching agents on enamel microhardness over time

Article Abstract:

The research reveals that different concentrations of carbamide peroxide used as bleaching agents, which were applied on the surface of the human dental fragments led to the decrease in enamel microhardness, is discussed. The characteristics of bleaching agents are presented. The graphical representation of estimated Knoop microhardness differences from baseline values at each measurement time is also presented.

United States, Science & research, Nitrogenous Fertilizer Manufacturing, Nitrogenous fertilizers, Urea, Research, Chemical properties

Similar abstracts:

• Abstracts: Calcium intake and peak bone mass. The effect of calcium supplementation on bone density during lactation and after weaning
• Abstracts: Doctoring! A reporter goes behind the scenes to see what practicing medicine really feels like. What you need to know
• Abstracts: Medical interviewing and interpersonal skills teaching in US medical schools: progress, problems, and promise
• Abstracts: Dietary fibre analysis - an overview. Effects of processing on dietary fibre in vegetables. Effects of different vegetables in mixed meals on glucose homeostasis and satiety
• Abstracts: A controlled trial of bismuth subsalicylate in infants with acute watery diarrheal disease. Racecadotril in the treatment of acute watery diarrhea in children

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.