Does the application of dimethyl sulfoxide improve resin bonding to eroded dentine? Four-year in vitro evaluation.

OBJECTIVE: To evaluate the effect of dimethyl sulfoxide (DMSO) on the microtensile bond strength (µTBS) and nanoleakage (NL) of universal adhesives on eroded dentine, immediately and after four years of water storage. METHODS: Sixty-four sound human molars were distributed into 16 groups according to (1) Dentine surface (sound and eroded dentine); (2) dimethyl sulfoxide application (with or without); (3) Application mode (etch-and-rinse or self-etch) and (4) Storage time (immediate and four years). One mild universal adhesive was used (Scotchbond Universal). The restoration was then performed with a composite resin and the specimens were sectioned into resin-dentine bonded sticks. Resin-dentine bonded sticks were tested (immediately and after four years of water storage) for µTBS (0.5 mm/min) or used to assess NL. Data on µTBS and NL were analyzed using four-way ANOVA and Tukey's test (α = 0.05). RESULTS: Only the 3-way cross-product interaction 'substrate vs DMSO vs time' was statistically significant (p = 0.007). Eroded dentine showed a lower mean of µTBS and a higher mean of NL values than sound dentine. However, when DMSO was applied, no significant decrease of µTBS or NL values was observed after four years of water storage, regardless of adhesive strategies, or dentine evaluated, when compared to immediate results. SIGNIFICANCE: Water-based DMSO pre-treatments not only prevent degradation of MDP-containing simplified adhesives but also serve as a potential alternative to improve long-term bonding properties to eroded dentine. The versatility of using a single pre-treatment for both self-etch or etch-and-rinse bonding to eroded dentin may facilitate future clinical applications.

Avaliação dos índices de placa e gengival de crianças portadoras de neoplasias submetidas a tratamento antineoplásico / Assessment of the plaque and gingival indices of children with neoplasy submitted to antineoplastic treatment

A terapia antineoplásica pode levar a inúmeras manifestações bucais, incluindo manifestações no periodonto. O objetivo deste trabalho foi avaliar o grau de comprometimento periodontal de crianças submetidas a tratamento antineoplásico. Foram examinadas 32 crianças, entre 3 a 15 anos, de ambos os sexos, que estavam sendo submetidas a tratamento no Hospital Aldenora Belo, principal centro de referência para terapia oncológica no Maranhão. Avaliou-se clinicamente a presença de lesões orais e os índices de placa bacteriana e gengival. A gengivite foi a manifestação oral mais incidente. O índice de placa predominante foi o escore 1 (placa não visível) e o índice gengival predominante foi o escore 2, caracterizando uma inflamação gengival moderada. Sendo assim, conclui-se que as condições clínicas do periodonto de crianças em tratamento antineoplásico evoluíram desfavoravelmente.