Osteogenic capacity of collagen in repair of established periodontal defects.

Periodontal bone defects were established in four dogs, with one proximal lesion and one furcation lesion in each quadrant. These defects were treated with the implantation of collagen membranes, collagen sponge or a combination of membrane and sponge, inserted between the mucoperiosteal flaps and the bone defects. Control sites were treated in a similar surgical manner to the experimental sites, but no collagen was inserted. Substantial amounts of new bone formed in those cases treated with the collagen products, especially those treated with the membrane either with or without the sponge. The membranes limited the infiltration of small round cells, whereas in the control sites, inflammatory cells infiltrated to the bone surface. New connective tissue attachment was established in experimental situations, especially with the use of the membranes alone or in conjunction with sponge.

Refractory chronic periodontitis: effect of oral tetracycline hydrochloride and root planning.

Refractory chronic periodontitis of 16 patients was treated by root planing and adjunctive tetracycline hydrochloride therapy. The antibiotic was taken orally one hour before root planing and continued for six days at a dosage of 250 mg six hourly. The clinical data for each patient were recorded as the number of probing depths in each of the 1-3 mm, 4-6 mm and 7-10 mm ranges. The Multivariate Analysis of Variance (MANOVA) procedure for repeated measurements was used to analyse the data. The results demonstrated that the number of sites with probing depths of 4-6 mm and 7-10 mm associated with incisors, canines, premolars and molars decreased with a corresponding increase in the number of sites in the 1-3 mm range. Incisor and canine teeth showed a better response to treatment than premolars, which responded better than molars. The cases were followed for varying periods of time from six months to two years following antibiotic therapy. The probing depth reduction achieved following root planing and tetracycline hydrochloride therapy was maintained during this review period.