In the present study, the proportion of mononuclear cells and percentages of CD4+ (OKT4+) and CD8+ (OKT8+) were determined in clinically healthy buccal mucosa in patients with recurrent minor aphthous ulceration (RAU) (n = 43) during active and inactive disease as compared with RAU-free controls (n = 15). In lamina propria, the total number of mononuclear cells and subset percentages were determined histologically and immunohistochemically. Mononuclear cell counts in patient specimens were significantly lower than in the control group. CD4+ percentages were not significantly different between controls and patients. CD8+ percentages of the patients were significantly increased during active RAU, but not during inactive RAU as compared with controls. In proportion to the total number of mononuclear cells, CD4+ and CD8+ cell counts per 0.25 mm2 were significantly lower in the patients during both active and inactive disease as compared with controls. Thus, RAU seems characterized by reduced numbers of mononuclear cells, including T-lymphocytopenia in the oral mucosa as such, features that appear more pronounced during active disease than during quiescence.

Fourty-three patients with oral mucosal lesions were divided into 3 groups based on the relationship between lesions and amalgam restorations. Group I consisted of patients with contact lesions confined to mucosal areas in contact with amalgam fillings. Group II patients had lichen planus lesions exceeding the area of contact with an amalgam filling and Group III comprised patients with lichen planus lesions without relation to amalgam fillings. Biopsies were embedded in epon and subjected to autometallography in order to demonstrate a possible accumulation of mercury in the affected mucosa. In 20 our of 21 patients in Group I, 4 of 11 patients in Group II and 4 of 11 patients in Group III, mercury was found in the lysosomes of macrophages and fibroblasts. In Group I the number of cells loaded with mercury was much higher than in Group II and in particular Group III. In the latter groups autometallographically demonstrated mercury was found almost exclusively in macrophages. Nineteen biopsies taken from patients with normal mucosa served as controls. Ten had occlusal (Group IV) and seven buccal fillings (Group V). The biopsies from the latter group were taken from areas opposing amalgam restorations. Two patients had no amalgam fillings (Group VI). The histochemical technique showed that three biopsies in Group IV (occlusal fillings only) and two in Group V (opposing buccal fillings) contained traces of mercury in the juxtaepithelial connective tissue. The silver enhanced mercury was found in macrophages. The two controls (Group VI) without amalgam fillings were devoid of precipitates.(ABSTRACT TRUNCATED AT 250 WORDS)

– The tissue distribution of helper/inducer and suppressor/cytotoxic T cells, Langerhans cells (LC) and HLA‐DR bearing cells was determined in normal oral mucosa by use of monoclonal antibodies OKT4, OKT8, OK.T6 and OKIal, respectively. OKT4+ and OKT8+ cells were invariably present in normal oral epithelium and in the lamina propria. OKT8+ cells were consistently seen inside the basal cell layer of the epithelium. The distribution of LC in oral epithelium showed regional variation. In palatal epithelium LC were evenly distributed in the basal half of the epithelium, whereas in buccal mucosa the highest concentration of LC was seen in the epithelium overlying the tips of connective tissue papillae. OKIal stained dendritic cells in the epithelium and plump cells with small dendritic processes in the connective tissue. Some of the latter were located close to the basal cells of the epithelium. The consistent relationship between immunocompetent cells and the epithelium of the oral mucosa suggests the presence of a local immunologic defence barrier in the oral mucosa.

The present long-term study indicates that RP can be used for root-end filling with a successful treatment outcome.