Success Rate of Dental Implants Placed in the Atrophic Posterior Maxilla with Intentional Sinus Floor Perforation in Lieu of Indirect Sinus Augmentation: A Retrospective Report of 26 Consecutive Patients and Literature Review

Abstract

Purpose: To assess surgical success rate of placing dental implants in the atrophic posterior maxilla engaging the maxillary sinus floor in patients with inadequate posterior maxillary alveolar bone height (PMABH). Methods: 26 patients with PMABH of 7 -10 mm had 39 implants placed between July 2012 and June 2014. These implants were placed protruding apically 1 -3 mm into the maxillary sinus engaging the sinus floor. At stage one, implants and cover screws were placed, followed by stage two, 5 -6 months later. The implants were considered osseo-integrated in the absence of symptoms, mobility and inflammation. Periapical radiographs were taken to rule out peri-implant radiolucency. Restorative treatment was completed 2 months thereafter. Patients were scheduled to have a dental exam (6 -12 months after delivery of prosthesis) and the implants were evaluated clinically and radiographically. A retrospective review was conducted to assess the surgical success rate of this treatment modality. Clinic charts, radiographs and digital implant log were reviewed for all patients with PMABH of 7 -10 mm who received dental implants in the posterior maxilla to determine the success rate of this treatment modality. Results: 26 patients who had 39 implants placed were included in the study. All implants (100%) were osseo-integrated at the time of uncovering (stage 2). None of the implants (0%) had mobility or inflammation around them. Stage 2 was successfully performed on all 39 implants (100%). All implants (100%) in these patients had been restored, and were in good condition 114without mobility or inflammation, and had been functioning well 6 -12 months after restoration. Conclusion: This study suggests that a high success rate can be attained placing dental implants in the posterior maxilla while perforating and engaging the cortical maxillary sinus floor. A future prospective study that compares this technique with the internal sinus lift would likely help elucidate this suggestion.