Optimum force and duration of toothbrushing to enhance gingival fibroblast proliferation and procollagen type I synthesis in dogs.

Abstract

Toothbrushing enhances gingival fibroblast proliferation, which promotes wound healing. Optimum force and duration of toothbrushing for stimulation of fibroblast proliferation are key factors in maximizing effects of toothbrushing on periodontal wound healing. We therefore evaluated the effects of different durations and forces of toothbrushing on proliferative activity and procollagen synthesis of gingival fibroblasts. Twelve dogs were used. In each dog, buccal gingivae of 12 teeth were examined for 3 weeks. Nine of these 12 teeth were each assigned to 1 of 9 different combinations of brushing force (0.98, 1.96, or 2.45 N) and duration (10, 20, or 40 seconds). The remaining 3 teeth received plaque removal without brushing, via a scaler. Force and duration of toothbrushing affected both proliferating cell nuclear antigen (PCNA)-positive and procollagen Type I C-peptide (PIP)-positive fibroblast ratios (P < 0.05). The highest ratio of PCNA-positive fibroblasts was produced by brushing at 1.96 N for 20 seconds. The highest ratio of PIP-positive fibroblasts was produced by brushing at 1.96 N for 10 seconds. Toothbrushing at certain forces and durations enhanced the proliferative activity and procollagen synthesis of gingival fibroblasts. The toothbrushing duration that increased procollagen synthesis (10 seconds) was shorter than that which increased fibroblast proliferative activity (20 seconds).