The influence of self-inflating soft tissue expander on the outcomes of horizontal alveolar ridge augmentation: A randomized controlled clinical and histological study.

OBJECTIVE: The present study was conducted to evaluate the effect of soft tissue augmentation using a self-inflating soft tissue expander when performed before horizontal alveolar ridge augmentation on the outcomes of the bone augmentation procedure. The primary outcome is the bucco-palatal radiographical changes in alveolar ridge width, while the secondary outcome is the quality of the augmented bone assessed histomorphometrically. MATERIALS AND METHODS: Sixteen patients underwent horizontal alveolar ridge augmentation using autogenous bone. For the test group, soft tissue expanders were used in a separate surgery before bone grafting surgery. For the control group, patients received treatment including single surgery of bone grafting associated with periosteal releasing incision. Implants were placed in both groups 6 months after bone augmentation. Bucco-palatal changes in alveolar ridge width were evaluated via cone-beam computed tomography. Augmented bone quality was assessed histomorphometrically. RESULTS: After 6 months, regarding radiographic bone width, there was no statistically significant difference between the two groups, as mean bone width in group I and group II were 8.57 mm and 8.75 mm, respectively. Regarding histomorphometric analysis, Group I showed significantly higher mean bone surface area fraction, higher median mature collagen area fraction, and higher median blood vessel count than Group II (p-value = .012), (p-value = .004), and (p-value = .014), respectively. CONCLUSION: Within the limitations of the present study, soft tissue expander has no influence on bone width gain after horizontal alveolar ridge augmentation with an autogenous bone block but may have a positive effect on the quality of augmented bone.

The impact of membrane perforation and L-PRF for vertical ridge augmentation with a xenogeneic block graft: an experimental study in a canine model.

OBJECTIVES: This study evaluated clinically and histologically the efficacy of modified perforated collagen membrane (PCM) and/or leukocyte- and platelet-rich fibrin (L-PRF) in combination with xenogeneic block bone graft in the vertical alveolar ridge augmentation. MATERIALS AND METHODS: Six adult mongrel dogs were enrolled in this randomized blinded study. After defect preparation, xenogeneic screw-fixed block graft was covered by an occlusive collagen membrane in group 1 that represented the control group (Block + CM). In group 2, L-PRF membrane was added first before top coverage by occlusive collagen membrane (Block + L-PRF + CM). Groups 3 (Block + PCM) and 4 (Block + L-PRF + PCM) were identical to the first two groups except that the occlusive collagen membrane was replaced by a perforated one. Following a healing period of 2 months, the dogs were submitted to the surgical reentry phase for clinical and histological evaluation. RESULTS: Clinically, no significant differences were found among all groups regarding vertical and horizontal ridge dimensions (p = 0.155, 0.492, respectively). Histomorphometric analysis revealed that the percentage of the total bone area and mature bone was significantly higher in group 4 (69.36 ± 2.72, 33.11 ± 5.18) compared to the control group (59.17 ± 4.27, 21.94 ± 2.86) (p = 0. 027, p = 0.029). CONCLUSION: The use of xenogenic block grafts in combination with a double-layered perforated collagen L-PRF membrane in vertical ridge augmentation appeared to improve the inductive power of this challenging defect type. CLINICAL RELEVANCE: Size and number of perforations may affect the mechanical and handling properties of the membrane.