Location of proliferating gingival cells following toothbrushing stimulation.
OBJECTIVE
Mechanical stimulation by toothbrushing promotes healing of gingivitis through accelerating cell proliferation. Junctional epithelium proliferates at periodontal pocket formation. A question is arisen whether toothbrushing contributes to the repair of gingival inflammation or deterioration of pocket formation. The location of proliferating cells in gingiva stimulated mechanically by toothbrushing was investigated.


METHODS
A total of 24 teeth of dogs underwent daily plaque removal with a curette (plaque removal) or both plaque removal and toothbrushing (toothbrushing). Proliferative activity of gingival cells in six individual zones was evaluated by assaying expression of proliferating cell nuclear antigen (PCNA).


RESULTS
Toothbrushing increased densities of PCNA-positive basal cells in the junctional epithelium, connective tissues adjacent to the junctional epithelium, the alveolar bone of the oral epithelial side and the oral epithelium. However, the densities of PCNA-positive cells at the apical portion of the junctional epithelium, connective tissues adjacent to the cementum and the alveolar bone of the periodontal ligament side did not increase following toothbrushing.


CONCLUSIONS
Toothbrushing promotes proliferation of gingival cells other than fibroblasts in periodontium and basal cells in the apical portion of the junctional epithelium. The repair of periodontal tissues might be promoted by toothbrushing within the limit of the direct mechanical stimulation.
Tomofuji
T
T
Department of Oral Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Sakamoto
T
T
Ekuni
D
D
Yamamoto
T
T
Watanabe
T
T
D000539:Alveolar Process / Q000166:cytology; D000818:Animals; D002452:Cell Count; D049109:Cell Proliferation; D003239:Connective Tissue Cells / Q000502:physiology; D003475:Curettage / Q000295:instrumentation; D003739:Dental Cementum / Q000166:cytology; D003773:Dental Plaque / Q000628:therapy; D012534:Dental Scaling / Q000295:instrumentation; D004285:Dogs; D004846:Epithelial Attachment / Q000166:cytology; D004847:Epithelial Cells / Q000502:physiology; D005347:Fibroblasts / Q000166:cytology; D005881:Gingiva / Q000166:cytology*; D010812:Physical Stimulation; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D014099:Toothbrushing
D018809:Proliferating Cell Nuclear Antigen