The aim of this controlled, clinical study was to evaluate guided tissue regeneration using a bioabsorbable membrane in periodontal intraosseous defects. Forty patients, each contributing one defect > or =4 mm in depth participated. The control group (18 individuals) received conventional flap therapy, while the test group (22 individuals) was treated using the bioabsorbable membrane, Guidor. Clinical assessments were made by one examiner, blinded with respect to treatment group, at baseline, 6 and 12 months following surgery. Baseline probing pocket depths of 7.7+/-1.4 mm in the membrane group and 7.6+/-1.9 mm in the control group were measured. Twelve month results showed a significant clinical attachment level gain in both control (1.1+/-1.8 mm), and membrane group (1.3+/-2.1 mm). Probing pocket depth reduction of 2.6+/-1.9 mm and 2.7+/-1.9 mm was observed in the respective groups. Bone sounding showed a non-significant gain of 0.4+/-1.8 mm and 0.6+/-1.4 mm at membrane and control sites, respectively. Radiographic evaluation confirmed these results. There were no significant differences found between treatment groups for any of the tested variables. Smoking had a negative effect on healing in both groups. In conclusion, clinical and radiographic results indicate that guided tissue regeneration using a bioabsorbable membrane at intraosseous defects did not predictably achieve greater clinical attachment level gain nor bone gain when compared to conventional flap therapy.

This study evaluated the influence of image processing of digital subtraction images on inter- and intra-examiner agreement relative to the detection of alveolar bone change on radiographs. 62 sites on digital subtraction images from standardized radiographs from patients requiring periodontal surgery were included in this study. The images were displayed as digital subtraction images, contrast enhanced subtraction images and as color-converted digital subtraction images. The images were projected in random order, analyzed by 4 interpreters and 1 of 8 possible diagnostic decisions was noted for each one of 62 sites. 2 months after the first evaluation, the slides were re-analyzed. 3 different computations (overall agreement, specific agreement and kappa-value) were calculated. The results indicated that image processing of subtraction images using pseudocolor display of the density changes might improve the intra- and inter-examiner agreement.