INFLUENCE OF THE TYPE OF BRACKET ON MICROBIAL COLONIZATION AND GENGIVAL CLINICAL CONDITION

It was hypothesized that patients using conventional brackets have greater bacterial colonization and worse gingival clinical condition compared to those using self-ligating brackets. Therefore, the objective of the study was to compare the influence of the type of bracket bonded on bacterial levels and gingival clinical condition. Twenty-one university students participated in the study. Each upper anterior tooth received an orthodontic bracket, one of the types conventional with elastic ligature (CL), conventional without elastic ligature (C) or self-ligating bracket (AL). After evaluation of the clinical parameters NCI (clinical attachment level), IG (gingival index), PS (pocket depth) and IP (plaque index) and professional dental prophylaxis, the brackets were bonded and the participants received oral hygiene instructions. The indices were measured again 7 and 21 days after bonding. The total bacterial load and the levels of Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Tannerella forsythia (T.f), and Treponema denticola (T.d) were quantified by qPCR. At 21 days, the sulcular levels of P.g and T.d were higher in the CL group. Except for P.g, the accumulation of bacteria on the brackets - total load, A.a, T.f, and T.d - increased over time for all bracket types. Although conventional brackets may have presented worse results for some microbiological parameters in relation to the clinical condition, the influence of conventional brackets with ligature was as negative as that of self-ligating brackets.