Influência de materiais obliteradores nas propriedades ópticas, mecânicas e superficiais da dentina

Abstract

Dentin hypersensitivity is a highly prevalent clinical condition characterized by short, sharp, and transient pain resulting from dentin exposure to thermal, tactile, evaporative, osmotic, or chemical stimuli. Despite the availability of different desensitizing agents, there is still no fully established protocol regarding the longevity and stability of these treatments. The objective of this study was to evaluate the influence of different obliterating materials on the topography and physicomechanical properties of dentin. For this purpose, 50 dentin slices obtained from the buccal surface of sound human molars were initially treated with 3% potassium nitrate associated with 5% glutaraldehyde and subsequently randomly allocated into five experimental groups (n=10): Group A: 3% potassium nitrate + 5% glutaraldehyde; Group B: 3% potassium nitrate + 5% glutaraldehyde + one layer of Universal Adhesive; Group C: 3% potassium nitrate + 5% glutaraldehyde + two layers of Universal Adhesive; Group D: 3% potassium nitrate + 5% glutaraldehyde + fluoride varnish; and Group E: 3% potassium nitrate + 5% glutaraldehyde + one layer of Universal Adhesive + Bulk Fill Flow resin. The specimens were evaluated immediately after material application, after coffee aging, and after simulated toothbrushing corresponding to 7, 30, 90, 180, and 360 days of clinical use. Color change, microhardness, and surface roughness analyses were performed, using appropriate statistical tests with a significance level of 5%. The results showed that Groups C and E presented greater color stability over time, whereas Groups C, D, and E maintained greater microhardness stability after the simulated erosive and abrasive challenges. Group E showed the highest surface roughness values, regardless of the evaluation period. It was concluded that the evaluated obliterating materials influenced the optical, mechanical, and surface properties of dentin, and that protocols involving multiple adhesive layers, fluoride varnish, and the association between universal adhesive and bulk fill flow resin demonstrated promising performance regarding the protection and longevity of dentin hypersensitivity treatment.