RESUMO
Eight subjects used a 10 per cent carbamide peroxide (Opalesence) home bleaching system in a mouthguard for 14 nights. Their periodontal health was assessed by measuring gingival crevicular fluid flow with a Periotron 6000, and subjects were given a questionnaire to assess the effects of the bleaching system. There was no significant change in the gingival crevicular fluid flow, recession, bleeding index or plaque index of any patient during the treatment phase. All treated teeth were lightened, and mild transient tooth sensitivity was common to all participants. One subject experienced internal tooth discoloration, possibly due to marginal leakage around an amalgam restoration.
Assuntos
Periodonto/efeitos dos fármacos , Peróxidos/farmacologia , Clareamento Dental , Ureia/análogos & derivados , Adulto , Análise de Variância , Peróxido de Carbamida , Esmalte Dentário/efeitos dos fármacos , Índice de Placa Dentária , Sensibilidade da Dentina/induzido quimicamente , Combinação de Medicamentos , Feminino , Líquido do Sulco Gengival , Humanos , Satisfação do Paciente , Índice Periodontal , Pulpite/induzido quimicamente , Inquéritos e Questionários , Clareamento Dental/efeitos adversos , Resultado do Tratamento , Ureia/farmacologiaRESUMO
Preliminary work has shown that the rate of dentin demineralization increases with increasing concentrations of citric acid. This rate subsequently diminishes at much higher concentrations. The purpose of this study was to more precisely identify the citric acid concentration which produces peak dentin demineralization and to determine if this demineralization process is time dependent. Flat dentin surfaces were prepared on the buccal and lingual sides of 15 bovine molars. 8 depressions were made in each dentin surface using a #8 round bur in a high-speed handpiece with air-water coolant. Various concentrations of citric acid solutions (weight per cent) were prepared, e.g., 0%, 10%, 20%, 25%, 30%, 35%, 40%, 65% and their respective pH's recorded. 3 microliters of each citric acid solution were placed in individual depressions on the dentin surfaces and left undisturbed for 1, 2 or 3 min. Cotton pellets were used to soak up the citric acid solution, along with any dissolved calcium, and were subsequently placed in 10 ml of 18 Me omega water. The parts per million calcium found in each water sample were determined using atomic absorption spectrophotometry. Peak dentin demineralization for 1-, 2- and 3-min application times occurred at 30% (pH = 1.55), 25% (pH = 1.62) and 25% (pH = 1.62) citric acid concentrations/(pH), respectively. Dentin demineralization was found to be time-dependent for all citric acid solution concentrations. The clinical significance of these findings is discussed.
