Histologic changes in the maxillary sinus membrane after sinus membrane elevation and the simultaneous insertion of dental implants without the use of grafting materials.

OBJECTIVE: The aim of this study was to evaluate the histologic changes in the maxillary sinus membrane after sinus membrane elevation and the simultaneous insertion of dental implants without additional grafting material. STUDY DESIGN: In 6 mongrel dogs, bilateral edentulated flat alveolar ridges were created in the maxilla. After 3 months of healing, an implant was unilaterally placed in the maxillary sinus in such a way that it protruded 5 mm into the maxillary sinus after sinus membrane elevation. On the opposite side, the maxillary sinus was left untreated as a control site. The animals were killed 6 months after surgery. The maxillary sinus mucosa was examined using light microscopy and scanning and transmission electronic microscopy. RESULTS: There were no morphologic or ultrastructural differences in the sinus membrane between groups. CONCLUSION: The results indicate that the surgical procedure by which implants are inserted into the sinus cavity by elevating the sinus membrane without adding any graft material appears to have little influence on the histologic characteristics of the sinus membrane.

Effects of sinus membrane elevation on bone formation around implants placed in the maxillary sinus cavity: an experimental study.

OBJECTIVE: The aim of this study was to investigate the amount of augmented bone tissue formed in the maxillary sinus after sinus membrane elevation and the simultaneous insertion of titanium implants without additional grafting material. STUDY DESIGN: An implant was placed bilaterally in the maxillary sinus of 6 adult female mongrel dogs in such a way that it protruded 4 mm or 8 mm into the maxillary sinus after sinus membrane elevation. The implants were left in place for 6 months. RESULTS: The mean height of newly formed bone in the sinus was 3.3 mm on the side with the 4 mm protruding implant and 3.2 mm on the side with the 8 mm protruding implant. There was no difference between the 2 sides regarding new bone height in the sinus (P > .05). CONCLUSIONS: The results indicate that the length of implant protrusion into the sinus cavity after sinus membrane elevation is not related to the height of new bone in the sinus.