Comparing the histological assessment following ridge preservation using a composite bovine-derived xenograft versus an alloplast hydroxyapatite-sugar cross-linked collagen matrix.

BACKGROUND: This randomized controlled trial was designed to evaluate the histological wound healing and alveolar ridge dimensional changes following ridge preservation using two different xenograft/collagen matrices. METHODS: Fifty-four patients each with non-molar teeth that required extraction and replacement with dental implants were enrolled. Teeth extractions were completed with minimal flap reflection and were randomized to receive ridge preservation with either 90% bovine-derived xenograft granules in a 10% porcine collagen matrix (Group A) or a sponge-like matrix of 80% microparticulate hydroxyapatite alloplast graft with 20% sugar cross-linked porcine type 1 collagen (Group B). After 16 weeks of healing and at the time of implant placement, a bone core biopsy was harvested followed by dental implant placement. The primary histological outcome evaluated were percentage of vital bone formation and connective tissue/other (fibrous tissue and marrow space). Secondary outcomes included the change in alveolar ridge width and the buccal and lingual ridge height. Statistical analysis was completed with two-sample t-test and Fisher exact test. RESULTS: Forty-four patients completed the study, 23 in group A and 21 in group B. Group B presented with statistically significantly (p = 0.02) more percentage of vital bone (39.3 ± 17.8) than group A (26.8 ± 15.8). No statistically significant difference was observed for changes in alveolar ridge dimensions. CONCLUSIONS: Group B, when used for ridge preservation, yields statistically significantly more vital bone over a 4-month healing period. Ridge dimension changes were similar between the two groups and were adequate for implant placement.

The application of leukocyte- and platelet-rich fibrin (L-PRF) in maxillary sinus augmentation.

BACKGROUND: Since the introduction of sinus augmentation in the 1970s the procedure has been performed with or without biomaterials. Autologous blood products (ABPs) for use in sinus augmentation was first introduced in the 2000s, to aid potentially in bone and soft tissue healing. METHODS: Three different applications of leukocyte- and platelet-rich fibrin (L-PRF) in maxillary sinus augmentation are presented in this case series. In case 1, L-PRF is used in bilateral sinus augmentation to support placement of implants to support a maxillary hybrid denture. Case 2 highlights the use of L-PRF in a complication associate with Schneiderian membrane elevation. Case 3 provides histology taken at the time of implant placement 6 months following L-PRF/xenograft sinus augmentation. RESULTS: All cases resulted in the successful placement of dental implants. In case 2, an osseodensification procedure was performed with freeze-dried bone allograft, which provided an approximate 4 mm of additional vertical height for implant placement. Histology from case 3 at 6 months post sinus augmentation demonstrated the presence of new vital bone in contact with the xenograft. CONCLUSION: To date, there is only a limited amount of evidence reporting on platelet-rich fibrin (PRF) or L-PRF use in maxillary sinus augmentation. Bone gain from either product has ranged from 3.2 to 11.8 mm, with the percentage of newly formed bone reported in case series as 33% ± 5%. Despite the lack of strong evidence, L-PRF appears to have beneficial effects on bone regeneration when used in sinus augmentation.