RESUMO
OBJECTIVES: The objective of this study was to compare the incidence of gingival fissures (GF) associated with the use of soft and medium bristle toothbrushes over three months. MATERIAL AND METHODS: A blind randomized crossover clinical trial was conducted with 20 high school students (14 females, 14-24 years old) using both toothbrushes type (soft and medium bristle) during 3 months each. Periodontal examinations and photographs of premolars and molars were recorded on days 0, 30, 60, and 90 of 1st phase. Following a 10-day washout period, the 2nd phase was carried out with the participants changing the assigned brush type. Toothbrushing perception was evaluated at the end of study through a questionnaire. A calibrated and blind examiner analyzed the photographs for GF presence. Differences in the GF incidence between toothbrushes type were analyzed by McNemar test, while factors associated with GF incidence were investigated by Poisson regression. RESULTS: Sixty-five percent (n = 13) of participants had at least one GF throughout the study, with 40% (n = 8) of them while using medium brushes only (p = 0.039). GF occurrence was significantly associated with medium brushes (IRR, 3.582; 95% CI 1.459-8.795; p = 0.005). 58.8% of participants reported gingival soreness or bleeding with medium brushes. CONCLUSIONS: Both toothbrushes led to the GF occurrence. Nonetheless, medium bristles toothbrushes determined a 3.58 times greater risk of developing these lesions. Clinical relevance The use of medium bristle brush is associated with greater incidence of gingival fissures. The presence of gingival fissures should be considered by the clinician when evaluating the toothbrushing habits of patients.
