Hipersensibilidade dentinária cervical: estudo de prevalência e avaliação in vitro de produtos experimentais

Abstract

The aim of this research was to study experimental substances for the treatment of cervical dentin hypersensitivity (CDH); and to study the prevalence of CDH in patients who received orthodontic treatment. Three studies were performed: studies 1 and 2 were in vitro; and study 3 was observational and cross-sectional. In studies 1 and 2, 186 bovine teeth were used. Dentine samples were cut out from the buccal cervical region of the teeth. The samples were 4x4x1 mm in size. The dentinal tubules were oppened with 24% EDTA. The samples received the treatments according to the groups: study 1 - I. Distilled Water (DW); II. Cavity Varnish (CV); III. Colgate® Sensitive Pro-ReliefTM (CS); IV. Bioglass 45S5 (45S5); V. Bioglass KSr (KSr); VI. Bioglass P (P); and VII. Bioglass PSi (PSi); study 2 - I. Distilled Water (DW); II. Cavity Varnish (CV); III. Colgate® Sensitive Pro-ReliefTM (CS); IV. Commercial NanoP® hydroxyapatite (NP); and V. Experimental hydroxyapatite obtained from eggshells (HA). After treatments, samples were submerged in saliva overnight; half of the samples received simulated brushing; and in all samples the following analyzes were performed: a) surface roughness (Ra and Rt); b) descriptive analysis of the dentin surface; c) total number vs. number of obliterated tubules; d) diameter of the tubules; and e) chemical composition of the surface. Two-way ANOVA test was used for statistical analysis of the roughness parameters (p ≤ 0.05). In study 3, 232 patients who underwent corrective orthodontic treatment were analyzed for CDH: a) self-reported; b) diagnosed with a tactile test; c) evaporative test with bellows; d) evaporative with triple syringe; and e) thermal testing. Dichotomous values (yes/no) and an 11-point NRS (Numeric Rating Scale) were used. The OHIP-14 and DHEQ-15 quality of life questionnaires were also applied. Chi-square, Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis (p≤0.05). The results of studies 1 and 2 showed that the experimental substances had higher roughness values than the controls, but had better performance in obliterating dentinal tubules, and the experimental hydroxyapatite showed formation of obliterating plugs even after the mechanical challenge of simulated brushing. Bioglasses KSr and PSi had concentrations of Ca and P on dentin surface higher than the other groups analyzed. The results of study 3 indicated that: CDH is higher in women and in individuals under 30 years of age, in individuals with gingival recession and in individuals who use conventional toothpaste, in the sample of patients after orthodontic treatment; the most affected teeth are the incisors and premolars; the different diagnostic tests indicated different prevalence values; and volunteers with CDH had worse results for quality of life. It was concluded that KSr and PSi bioglasses are promising for tubule obliteration and dentinal remineralization; the experimental hydroxyapatite obtained from eggshells is a promising material, mainly in terms of resistance to mechanical challenge; the prevalence of CDH is higher in women, in individuals under 30 years of age and with gingival recession.