Cirurgia de elevação do assoalho do seio maxilar com enxerto autógeno intraoral: análise clínica e histopatológica no final dos períodos de incorporação e maturação óssea para instalação de implantes

Abstract

This experimental study, in vivo, examined clinically and histopathologically the possibility of reducing the waiting time for implants installation in regions submit to elevation of maxillary sinus floor with autogenous intraoral bone graft. We selected ten patients seeking medical care in FO/UFJF clinics, which showed a bilateral dental absence and subsequent vertical alveolar bone atrophy posterior maxilla with remaining ridge < 4 mm. The same patient was part of two groups because the procedure was bilateral, being considered the right or left side (GI = test, two months, incorporation) (n = 10), left or right (GII = control, 6 months, maturation) (n = 10) for placing the graft and subsequent installation of the implants. The donor area for collecting autogenous bone is the mandibular branch. The selected technique for filling the receiving area was access through the side wall of the maxillary sinus and placement of bone graft in the space created after raising the Schneiderian membrane. At the time of implant placement, samples were obtained from the bone repair for histopathology. After six months of each group the reopening of procedures for placement of healing abutments and finalization of using prosthesis over implants were performed. Samples were processed and the sections stained with hematoxylin and eosin and submitted to descriptive and automatic analysis. Histopalógicos results in significant differences were identified between the areas of hard tissue in the GI group (mean = 38.12 ± 6.64%) and GII (mean = 38.45 ± 9.27%), with a strong correlation between two groups (r = 0.93). Clinically, patients were observed during post-operative periods of all the surgical steps with respect to incorporation of the graft and the primary stability. Microscopic characteristics of both groups showed the presence of new bone formation. Among the patients who participated in the study, five (50%) have received the final prosthesis. Two are awaiting the period required for the installation of permanent prostheses procedure, while the remaining three are in osseointegration phase. In conclusion, the fact that the samples of test and control groups show statistically biocompatible, suggests that the period of two months may be enough for the implants insertion after maxillary sinus floor augumentation with autogenous bone graft collected from the mandibular branch region, making this predictable procedure in the rehabilitation of the atrophic posterior maxilla with remaining ridge < 4 mm.