“…Nakagaki et al [1985] reported that the fluoride concen trations in human cementum were highest at or near the ce mentum surface and decreased towards the interior of the tissue, showing an occasional peak at the cementodentinal junction (CDJ). The distribution pattern o f the fluoride in human cementum, however, was determined by tooth type and the individual [Murakami et al, 1987], Nakagaki et al [1988] also demonstrated a relationship between fluoride distribution and histological structure. It was clear from these studies that the fluoride concentration in human ce mentum increases with age , In other reports it was suggested that the fluoride concentra tions in the cementum were also influenced by the fluoride concentrations in the drinking water [Yoon et al, 1960;Kato ct al., 1992], Human tooth samples, however, are frequently obtained from patients with periodontal disease.…”