A histological study of non-ceramic hydroxyapatite as a bone graft substitute material in the vertical bone augmentation of the posterior mandible using an interpositional inlay technique: A split mouth evaluation.

The aim of this study was to compare the influence of graft material (non-ceramic hydroxyapatite versus autologous bone) on bone behaviour and perform a resonance frequency analysis of implants placed in augmented sites to evaluate stability. For this study, 11 patients with bilateral edentulous areas in the mandibular posterior region were selected. Alveolar augmentation osteotomies were bilaterally (split mouth design) performed. In one hemiarch, the space generated by the osteotomy was grafted with an interpositional intra-oral autologous bone graft (control group). In the other hemiarch, the space generated by the osteotomy was grafted with an interpositional non-ceramic hydroxyapatite (ncHA) (test group). The groups were randomized. After 6 months of healing, a bone sample was retrieved from each side for histological evaluation using a trephine drill that was 2-mm in internal diameter. The implant stability quotient (ISQ) was measured by the resonance frequency immediately following implant placement at baseline and after 6 months of follow-up. Good incorporation of the graft was observed in both groups; however, in the test group, a residual-grafted material was observed. Bone density and marrow spaces were similar between groups. Correlations between the ISQ values and the histometric variables were not observed (p>0.05). The results of this trial suggest that both intra-oral autologous bone and ncHA may be elected as interpositional grafting materials to vertically augment posterior atrophic mandibles.

Stability of implants placed in augmented posterior mandible after alveolar osteotomy using resorbable nonceramic hydroxyapatite or intraoral autogenous bone: 12-month follow-up.

PURPOSE: This prospective, controlled split-mouth study evaluated the stability of dental implants placed in the augmented mandibular areas with alveolar segmental "sandwich" osteotomies using nonceramic hydroxyapatite (ncHA) or autogenous bone. MATERIAL AND METHODS: This study included 11 bilaterally partially edentulous mandibular patients in a split-mouth design. Alveolar augmentation osteotomies were performed bilaterally with interpositional ncHA graft (test group) or interpositional intraoral autogenous bone graft (control group). After 6 months of healing, four implants (two implants in each side) were placed in each patient. Forty-four implants were inserted and loaded after 6-month healing period. At 1-year follow-up, radiographic, prosthetic, and resonance frequency analysis parameters were assessed. Success criteria included absence of pain, sensitivity, suppuration, and implant mobility; absence of continuous peri-implant radiolucency; and distance between the implant shoulder and the first visible bone contact (DIB) < 2 mm. RESULTS: After a 1-year loading period, the overall implant survival rate was 95.45%, with two implant losses (one of each group). Among the surviving implants (42 out of 44), two did not fulfill the success criteria; therefore, the implant success was 90.90%. DIB was 0.71 ± 0.70 and 0.84 ± 0.72 mm for ncHA and autogenous bone grafts, respectively (p > .05). Implant stability measurements were similar between the groups during the 12-month follow-up (p > .05). CONCLUSION: Within the limits of this study, the implants placed either in sites augmented with ncHA or autogenous bone seem to represent a safe and successful procedure, at least, after 12-month follow-up.

Bone-to-implant contact around immediately loaded direct laser metal-forming transitional implants in human posterior maxilla.

OBJECTIVE: Direct laser metal forming (DLMF) is a procedure in which a high-power laser beam is directed onto a metal powder bed and programmed to fuse particles according to a computer-aided design file, generating a thin metal layer. This histologic study evaluated the bone-to-implant contact (BIC%) around immediately loaded DLMF transitional implants retrieved after 2 months from posterior human maxillae. METHODS: Twelve totally edentulous individuals (mean age, 66.14 ± 2.11 years) received DLMF transitional implants divided in twelve immediately loaded (IL) and twelve unloaded (UI) implants. These transitional implants were placed between conventional implants to support the interim complete maxillary denture during the healing period. After 8 weeks, the transitional implants and the surrounding tissue were removed and prepared for histomorphometric analysis. RESULTS: Mature woven preexisting bone lined by newly formed bone in early stages of maturation were found around all retrieved implants. Histometric evaluation indicated that the mean BIC% was 45.20 ± 7.68% and 34.10 ± 7.85% for IL and UI, respectively (P <0.05). CONCLUSION: The present data obtained in humans showed that, although both IL and UI presented good BIC%, IL DLMF implants had a higher BIC% in the posterior maxilla.

Alveolar osteotomy associated with resorbable non-ceramic hydroxylapatite or intra-oral autogenous bone for height augmentation in posterior mandibular sites: a split-mouth prospective study.

BACKGROUND: The presence of the inferior alveolar nerve within the body of the mandible could jeopardize the placement of dental implants. Previous studies have shown that the interpositional osteotomy for posterior mandible ridge augmentation could be a predictable procedure. Nevertheless, there are few prospective, controlled, and randomized studies that evaluated this technique using different bone graft materials. PURPOSE: This prospective, controlled split-mouth study evaluated, using tomographic and Resonance Frequency Analyses (RFA), implants placed in the augmented mandibular area. MATERIAL AND METHODS: Alveolar augmentation osteotomies were performed bilaterally in 12 partially edentulous mandibular patients in a split-mouth design. The alveolar segmental osteotomies were assigned in two groups: test group, interpositional non-ceramic hydroxylapatite bone graft, and control group, interpositional intra-oral autogenous bone graft. After 6 months healing, implants were placed. The tomographic measurements of bone gain were recorded at baseline and 6 months after surgery, when the implants were placed. At 12 months after osteotomy, RFA were performed for each implant. RESULTS: The mean of bone gain 6.5 ± 2.4 mm and 7.0 ± 1.76 mm to control and test group, respectively (P > 0.05). RFA values between groups were similar at baseline and 12 months follow-up (P > 0.05). CONCLUSION: Alveolar osteotomies associated with sandwich interpositional bone graft, independently of bone graft, resulted in bone formation over a period of 12 months.