Extraction and Socket Preservation before Implant Placement Using Freeze-Dried Allograft (FDBA) and Platelet-Rich Fibrin in Smokers: Radiographic and Histological Evaluation

Background: Dental extraction can initiate a sequence of biological events that may lead to an insufficient bone volume, which can compromise implant placement. To minimize bone loss, alveolar ridge preservation procedures were developed. However, smoking has been shown to adversely affect the outcomes of the procedures. Hence, this clinical study aimed to assess the ability of platelet-rich fibrin to maintain ridge volume and its ability to generate vital bone in smokers. Methods: Eighteen current heavy smokers with a total of forty upper molars indicated for extraction and implant placement were randomly allocated to four different groups: an advanced platelet-rich fibrin group (A-PRF) (n = 10), a factor-enriched bone graft matrix covered by A-PRF group (A/S-PRF) (n = 10); a freeze-dried bone allograft covered by a crosslinked collagen membrane group (FDBA/CM) (n = 10), which served as a positive control; and a negative-control resorbable collagen plug group (RCP) (n = 10). Two consecutive high-resolution CBCT images were taken for each augmented socket to evaluate the bone volume, one at baseline and the other after six months, and four different measurements (vertical height, horizontal 1 mm H1, horizontal 3 mm, and horizontal 5 mm) were taken for each image. To evaluate the bone vitality, three bone samples were harvested for each group and were analyzed histologically using H and E staining. The results were analyzed using SPSS version 26.0 through the Wilcoxon sign rank test and Kruskal-Wallis test. Results: In terms of preserving bone volume, A/S-PRF showed no significant reduction in bone after six months, while A-PRF showed a significant loss according to two measurements (vertical and horizontal 5 mm), and the last two groups showed a significant loss in all four measurements. For vital bone formation, three groups (A-PRF, A/S-PRF, and RCP) showed the generation of only vital bone, while the fourth group (FDBA/CM) showed the generation of a mixture of vital and non-vital bone. Conclusions: Based on the outcomes of this study, PRF was able to minimize bone loss following dental extraction and generate vital bone in smokers.