Effects of topical application of chlorhexidine on plaque and gingivitis in monkeys

All teeth except the lower right canine, premolars and molars, in each of 4 adult male macaque monkeys with heavy plaque deposits and severe gingivitis, were scaled and polished daily for 5 days, followed by daily topical applications of 2% aqueous chlorhexidine gluconate. Minimal amounts of simple plaque containing epithelial cells and Gram positive cocci formed on the treated teeth whereas the untreated teeth retained heavy deposits of complex plaque. In chlorhexidine treated areras the clinical level of gingivitis appeared to subside to a minimum after 15-20 days. Histomorphometric assessments of gingivitis after 42 or 52 days treatment were made on decalcified paraffin sections, by measuring the total area of gingival connective tissue and the area containing inflammatory cells and calculating the proportion of gingival tissue affected. A total of 21 teeth were assessed. Untreated teeth had from 16-40% of the gingivba inflamed, treated teeth only 0-6%. Thus daily topical application of chlorhexidine significantly inhibits plaque accumulation and maintains a significant reduction in gingivitis in these animals. No differences in the nature or degree of keratinization could be detected between treated and untreated areas, nor were there any visible side effects of the use of chlorhexidine for this period.