LED photobiomodulation effect on the bleaching-induced sensitivity with hydrogen peroxide 35%-a controlled randomized clinical trial.

OBJECTIVES: The aim of this study was to evaluate the effect of a protocol of photobiomodulation (PBM) with light-emitting diodes (LED) on the clinical risk of bleaching-induced sensitivity. MATERIALS AND METHODS: Sixty-four volunteers were selected and randomly divided in two groups, placebo (PG) and LED (LG). The LG received PBM irradiation and tooth bleaching, while the PG received tooth bleaching and simulation of the irradiation. The occurrence of painful sensitivity was recorded during the dental bleaching; immediately after bleaching; and 24, 48, and 72 h after tooth bleaching. At the same measurement times, data were collected on the intensity of sensitivity (VAS and NRS scale) and teeth affected by bleaching-induced sensitivity. A questionnaire sought to measure how the painful sensitivity influenced basic daily activities. Tooth color measures were performed using subjective and objective methods. RESULTS: LED irradiation decreased the occurrence of sensitivity at all studied evaluation times as well as its intensity, with the exception of the 72-h data when both groups presented no difference. Teeth affected by bleaching-induced sensitivity were significantly greater in the PG. Color measurements presented no differences between the groups in the recently after and later measures. CONCLUSIONS: PBM with LED decreases sensitivity risk and sensibility intensity during and after office bleaching and causes no influence on the shade degree of whitening achieved. The decrease in tooth sensitivity provided more comfort and less suffering while drinking. CLINICAL RELEVANCE: LED irradiation is a promising intervention in the control of bleaching-induced sensitivity. TRIAL REGISTRATION: RBR-7hpfwj. Sensitivity intensity measured by the VAS scale (0-10) in the first whitening session (Graphic A) and second whitening session (Graphic B). Significance level set at ≤ 5%. *Mann-Whiteney U test. Columns followed by the same letter are significant different (ap < 0.001; bp < 0.001; cp < 0.001; dp =0.013; ep < 0.001; fp < 0.001; gp < 0.001; hp = 0.002).

Use of sonic waves in bubble formation, microhardness and fluoride release of a high-viscosity glass-ionomer cement.

AIM: High-viscosity glass-ionomer cements (HV-GIC) are indicated for restorations but their viscosity favors the inclusion of bubbles within it. This study aimed to evaluate the use of ultrasonic and sonic waves in bubble formation, microhardness and fluoride release in a HV-GIC, also considering a different powder:liquid ratio (P/L). METHODS: Twenty-four molars with occlusal cavities were divided into four groups (N = 6): CG, HV-GIC with manual insertion; UG, application of ultrasonic waves; SG, application of sonic waves; and FG, HV-GIC fluid (1:2 P/L) with manual insertion. After 24 hours, bubbles and microhardness (50 g/5 s) were measured. Fluoride release (N = 10) was evaluated in CG, SG and UG after cariogenic challenge for 11 days. Microhardness, total area and number of bubbles, and fluoride release were submitted to ANOVA and Tukey's test. The average size of bubbles was analyzed by Kruskal-Wallis test (α = 5%). RESULTS: FG presented the lowest value of microhardness and higher average size for bubbles (P < .05). Differences concerning total number, total area occupied by bubbles and fluoride release were not found (P > .05). CONCLUSION: The use of sonic and ultrasonic waves had no influence on bubble formation, microhardness and fluoride release of a HV-GIC. Changing the P/L is not recommended.

Avaliação de técnicas de inserção do cimento Portland na confecção do plug apical em dentes com ápice aberto / Evaluation of Portland cement insertion techniques for apical plug confection in teeth with open apex

Introdução: dentes com ápices abertos dificultam o preparo biomecânico e a formação de um batente apical adequado. Uma das alternativas para induzir a a pacificação e selar o forame apical aberto com um plug apical. Diferentes técnicas podem ser adotadas para a inserção e condensação desse material. Objetivo: avaliar radiograficamente a confecção do plug apical por meio de diferentes técnicas de inserção do cimento Portland (CP). Métodos: foram utilizados 40 pre-molares unirradiculares extraídos, instrumentados e ampliados via coronária e apical, ate a lima K #140. Os dentes foram divididos em quatro grupos, de 10 espécimes cada, de acordo com a técnica de inserção do cimento para confeccao do plug apical: Grupo I, cone de guta-percha; Grupo II, aplicador de MTA; Grupo III, broca lêntulo; Grupo IV, sistema de agulha de maior calibre. Foi analisada a qualidade de preenchimento radiográfico do plug apical confeccionado com CP e inserido por meio de diferentes técnicas. Os dados foram tabulados e submetidos ao teste estatístico não-paramétrico de Kruskal-Wallis, com comparações individuais entre os grupos (Student-Newman-Keuls) (p < 0,05). Resultados: o Grupo I obteve o maior índice de sucesso (80%), em relação aos demais grupos; porem, apresentou diferença estatisticamente significativa apenas quando comparado ao Grupo IV. Não houve diferença estatística significativa entre os demais grupos. Conclusão: a técnica de inserção do cimento com o cone de guta-percha mostrou-se superiora técnica com o sistema de agulha, tendo uma tendencia a ser melhor do que as demais técnicas.