Polylactide and polyglycolide sponge used in human extraction sockets: bone formation following 3 months after its application

Objectives: The aim of this study was to evaluate (i) the degree of bone mineralization in the alveolar sockets 3 months following the use of a bio-absorbable graft material and (ii) the degree of resorption of the grafted material. Materials: Twenty patients, undergoing periodontal therapy, participated in this study. All patients were scheduled for extraction of one or more compromised monoradicular teeth and scheduled for replacement of the extracted teeth with dental implants. Methods: Following elevation of full-thickness flaps and extraction of teeth, the alveolar sockets were filled with a bioabsorbable polylactide-polyglycolide acid sponge (Fisiograft(R)) (Test group - T) or natural healing by clot formation was allowed (Control group - C). The flaps were sutured with no attempt to achieve primary closure of the surgical wound. Re-entry for implant surgery was performed 3 months following the extractions. Results: Fifteen biopsies (seven T and nine C) were harvested from the sites where the implants were placed. The biopsies harvested from the T sites revealed that the alveolar sockets healed with newly trabecular bone, highly mineralized and well structured. Particles of the grafted material could not be identified in any of the T biopsies. The bone formed in the C sites was also well structured, with a slightly minor percentage of mineralized bone. In both T and C biopsies, the apical portion presented a higher degree of mineralization compared with the coronal portion. Conclusions: The results of this study indicated that the use of a bio-absorbable synthetic sponge of polylactide-polyglycolide acid did not interfere with the formation of new bone in the alveolar sockets and that the characteristics of the 3-month newly formed bone seemed to be optimal for dental implants' insertion. The biocompatibility, safety and characteristics of Fisiograft(R) suggest that the material is suitable for filling alveolar sockets following extractions, to prevent volume reduction and collapse of the overlying soft tissue flaps.