Effects of anti-inflammatory agents, vitamins and bactericidal agents in liquid dentifrices on periodontitis in the rat

The purpose of this study was to investigate the effects of anti-inflammatory agents, vitamins and bactericidal agents in liquid dentifrices on experimentally induced periodontitis in the rat. Three liquid dentifrices -1) liquid dentifrices containing anti-inflammatory agents ("ε-amino capronic acid and dipotassium glycyrrhizinate), vitamins (tocopheryl acetate) and bactericidal agents (3-methyl-4-isopropylphenol and cetylpyridinium chloride), 2) liquid dentifrices containing only bactericidal agents, and 3) liquid dentifrices without any anti-inflammatory agents, vitamins or bactericidal agents (control) were compared. Periodontitis was induced by a ligature on the mandibular first molars of both sides in 26 male Wistar rats (8-week-old) for 4 weeks. After removal of the ligature, 20 rats were divided into 3 experimental groups and each liquid dentifrice was topically applied to the gingival sulcus of the mandibular first molars of both sides once a day for 2 weeks. The remaining 6 rats served as the baseline. The mandible was resected, fixed, decalcified and then paraffin-embedded to obtain bucco-lingual sections. The sections were stained with hematoxylin and eosin, Mallory staining and immunohistochemical staining for tumor necrosis factor (TNF)-alpha or 8-hydroxy-2`-deoxyguanosine (8-OHdG), and then analyzed histometrically. The liquid dentifrices containing anti-inflammatory agents, vitamins and bactericidal agents and those containing bactericidal agents alone significantly decreased the numbers of polymorphonuclear leukocytes and blood vessels in the subepithelial connective tissue of the junctional epithelium, and the number of TNF-alpha-positive cells in the periodontal ligament compared to the control dentifrice. Rats receiving topical application of liquid dentifrices containing anti-inflammatory agents, vitamins and bactericidal agents showed a higher density of collagen and lower number of 8-OHdG cells as compared to those receiving topical application of the liquid dentifrices containing bactericidal agents and the control dentifrice. In addition, there were no significant differences in the numbers of polymorphonuclear leukocytes or blood vessels between the baseline and the control dentifrice group. These results showed that anti-inflammatory agents, vitamins and bactericidal agents in liquid dentifrices have additional effects of improving inflammation in periodontal tissues. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 51(3) : 2