In-Office Tooth Bleaching for Adolescents Using Hydrogen Peroxide-Based Gels: Clinical Trial

Abstract The aim of the present study was to evaluate colorimetric changes and tooth sensitivity in adolescents and young patients submitted to tooth bleaching with 20% and 35% hydrogen peroxide. A randomized, controlled, clinical trial was conducted with 53 patients aged 11 to 24 years who were allocated to groups based on the use of the following commercial products: Whiteness HP - FGM® (35% hydrogen peroxide); Whiteness HP Blue Calcium - FGM® (35% hydrogen peroxide); and Whiteness HP Blue Calcium - FGM® (20% hydrogen peroxide). After the bleaching procedure, the visual analog scale was used to measure tooth sensitivity and the Vita Classical Shade guide was used to determine changes in tooth color. Statistical analysis involved the Friedman, Kruskal-Wallis and Student-Newman-Keuls tests, with p≤0.05 considered indicative of statistical significance. The addition of calcium contributed to a reduction in tooth sensitivity, especially when the lower concentration of hydrogen peroxide (20%) was used. Tooth sensitivity occurred in a transitory way and did not influence the tooth bleaching process. Significant differences in color were found after each of the two bleaching sessions. In-office tooth bleaching was considered an effective method for adolescents and young adults. Further studies in this population are necessary in order to fully evaluate the effects of bleaching in young teeth.

Resumo O objetivo do presente estudo foi avaliar alterações colorimétricas e sensibilidade dentária em adolescentes e jovens submetidos ao clareamento dental com peróxido de hidrogênio a 20% e 35%. Foi realizado um ensaio clínico controlado e randomizado com 53 pacientes, com idade entre 11 e 24 anos, que foram alocados em grupos com base nos seguintes produtos comerciais: Whiteness HP - FGM® (35% peróxido de hidrogênio); Whiteness HP Blue Calcium - FGM® (peróxido de hidrogénio a 35%); e Whiteness HP Blue Calcium - FGM® (20% de peróxido de hidrogênio). Após o procedimento de clareamento, a escala analógica visual foi utilizada para medir a sensibilidade dentária e a escala clássica Vita® foi utilizada para determinar as alterações de coloração. A análise estatística envolveu os testes de Friedman, Kruskal-Wallis e Student-Newman-Keuls, com valor de p≤0,05 considerado indicativo de significância estatística. A adição de cálcio contribuiu para uma redução da sensibilidade dentária, especialmente quando se utilizou a menor concentração de peróxido de hidrogénio (20%). A sensibilidade dentária ocorreu de forma transitória e não influenciou o processo de clareamento dos dentes. Foram encontradas diferenças significativas na cor após cada uma das duas sessões de clareamento. O clareamento dental de consultório foi considerado um método eficaz para adolescentes e adultos jovens. Estudos adicionais nesta população são necessários para avaliar completamente os efeitos do clareamento em dentes jovens.

Controlled clinical trial addressing teeth whitening with hydrogen peroxide in adolescents: a 12-month follow-up

OBJECTIVES: To evaluate the colorimetric change in incisors and canines of adolescents aged 12 to 20 years submitted to at-home whitening and to evaluate satisfaction, sensitivity and discomfort during the procedures through a questionnaire. METHOD: Thirty adolescents were randomly assigned to the following groups: 1) 6.0% hydrogen peroxide (White Class with calcium - FGM); 2) 7.5% hydrogen peroxide (White Class with calcium - FGM); 3) 10% hydrogen peroxide (Oral B 3D White - Oral-B); 4) Control group - placebo. Assessments were performed prior to treatment as well as at 7, 30, 180 and 360 days after treatment. Friedman’s ANOVA was used to analyze color. The Kruskal-Wallis test followed by Dunn’s post hoc test was used to compare the groups at the different evaluation times. Answers on the questionnaires were ranked, and non-parametrical tests were employed. The groups were compared in each period using the Kruskal-Wallis test followed by the Student-Newman-Keuls test. Categorical data were analyzed using Fisher's exact test, and the Wilcoxon test was used for the analysis of different periods. P-values were corrected using the Hyan-Holm step-down Bonferroni procedure. Clinicaltrials.gov: NCT01998386. RESULTS: Similar results were obtained one month after treatment with both tooth whitening gels and whitening strips. Patients were partially satisfied with the treatment after the first and second weeks and would recommend it. All products demonstrated color stability after 12 months of follow-up. CONCLUSIONS: The bleaching procedure was efficient, and the patients could perceive its result. Further investigations are needed to determine the effects of bleaching on young teeth.

Efeito citotóxico dos cimentos de ionômero de vidro em cultura celular / Cytotoxic effect of glass ionomer cements in cell culture

Objetivo: Avaliar a toxicidade de cimentos de ionômero de vidro (CIV) quimicamente ativados em culturas de células, após aglutinação do material e reação de presa. Materiais e Métodos: Dividiu-se os materiais em 9 grupos experimentais: I: controle, li (AP) Riva Self Cure (SOl), 111 (PP) Riva Self Cure (SOl), IV (AP) Maxxion R (FGM), V (PP) Maxxion (FGM), VI (AP) Vitro Molar (DFL), VII (PP) Vitro Molar (OFL), VIII (AP) KetacMolar Easymix, IX (PP) Ketac Molar Easymix (3M!ESPE). Manipularam-se os CIV conforme instruções do fabricante sendo depositados em laminulas em contato com a cultura de células logo após a aglutinação do material e após a reação de presa. A ação dos materiais sobre os fibroblastos cultivados foi analisada sobre o crescimento celular no curto, longo prazo e no ensaio de viabilidade e proliferação celular. Resultados: Grupos que receberam materiais após a presa apresentaram número de células viáveis e porcentagens menores que o grupo controle, porém permitiram crescimento celular durante todo experimento. Quando colocados em contato com as células logo após a aglutinação, induziram morte celular imediata. O material que demonstrou menor atividade citotóxica em fibroblastos foi o Ketac- Molar Easymix (3M!ESPE). Conclusão: Todos os CIV testados apresentaram-se tóxicos antes da reação de presa, entretanto após a reação de presa, permitiram crescimento celular

Aim: The aim of the present study was to assess the toxicity of different chemically activated GICs in fibroblast cell cultures post-agglutination (PA) and post-setting reaction (PS). Material and Methods: The materiais were divided into nine experimental groups: Group I - control; Group li (PA) - Riva Self Cure (SOl); Group 111 (PS) - Riva Self Cure (SOl); Group IV (PA) - Maxxion R (FGM); Group V (PS) - Maxxion (FGM); Group VI (PA) - Vitro Molar (OFL); Group VII (PS) - Vitro Molar (OFL); VIII (PA) - Ketac Molar Easymix; and Group IX (PS) - Ketac Molar Easymix (3M! ESPE). The cements were mixed following the manufacturers' instructions, deposited on glass slip covers and placed into contact with the cell cultures immediately following the agglutination of the material or after the setting reaction. The effect of the materiais on the cultivated fibroblasts was analyzed in terms of short-term and long-term cell growth as well as in viability and cell proliferation assays. Results: When placed in contact with the cells immediately follo- wing agglutination, the materiais caused immediate cell death. The groups having received the materiais following the setting reaction had a lower number and percentage of viable cells in comparison to the control, but the materiais allowed cell growth throughout the experiment. KetacMolar Easymix (3M!ESPE) was the glass ionomer cement with the least amount of cytoto- xic activity on fibroblasts. Conclusion: Ali glass ionomer cements tested were toxic prior to the setting reaction.However after setting reaction, allowed cell growth