OBJECTIVE: The aim of this study was to examine the relationship between bracket design and ratio of five proinflammatory cytokine, in gingival crevicular fluid (GCF), and bacterial adhesion without tooth movement influence. DESIGN: The sample was comprised of 20 participants, aged 11 to 15 years old (mean age: 13.3 years±1.03). A conventional Gemini™ metallic bracket and two self-ligating brackets, In-Ovation®R and SmartClip™, were bonded to the maxillary incisors and canines. GCF was collected using a standard filter paper strip before and 60days after bonding. The cytokine levels (IL-12, IL-1α, IL-1β, IL-6 and TNF-α) were performed by the LUMINEX assay. The levels of the red and orange bacterial complexes were analyzed by the Checkerboard DNA-DNA hybridization. The data of cytokine and bacterial complexes were carried out using the non-parametric tests at 5% of significance level. RESULTS: Increased cytokine levels were observed. However, only the SmartClip™ group showed a significantly increased level of TNF-α (p=0.046). The SmartClip™ brackets group presented higher levels of red complex bacteria. CONCLUSIONS: The bracket design affected cytokine levels and bacterial adhesion since it was observed that the proinflammatory cytokines released in GCF to the SmartClip™ group showed an increase in the TNF-α levels associated with higher bacterial levels, which possibly represents greater inflammatory potential. Thereby, the bracket design should be considered in patients with risk of periodontal disease and root resorption.
OBJECTIVE: The aim of this study was to examine the relationship between bracket design and ratio of five proinflammatory cytokine, in gingival crevicular fluid (GCF), and bacterial adhesion without tooth movement influence. DESIGN: The sample was comprised of 20 participants, aged 11 to 15 years old (mean age: 13.3 years±1.03). A conventional Gemini™ metallic bracket and two self-ligating brackets, In-Ovation®R and SmartClip™, were bonded to the maxillary incisors and canines. GCF was collected using a standard filter paper strip before and 60days after bonding. The cytokine levels (IL-12, IL-1α, IL-1β, IL-6 and TNF-α) were performed by the LUMINEX assay. The levels of the red and orange bacterial complexes were analyzed by the Checkerboard DNA-DNA hybridization. The data of cytokine and bacterial complexes were carried out using the non-parametric tests at 5% of significance level. RESULTS: Increased cytokine levels were observed. However, only the SmartClip™ group showed a significantly increased level of TNF-α (p=0.046). The SmartClip™ brackets group presented higher levels of red complex bacteria. CONCLUSIONS: The bracket design affected cytokine levels and bacterial adhesion since it was observed that the proinflammatory cytokines released in GCF to the SmartClip™ group showed an increase in the TNF-α levels associated with higher bacterial levels, which possibly represents greater inflammatory potential. Thereby, the bracket design should be considered in patients with risk of periodontal disease and root resorption.