A Multicenter Retrospective Study Comparing Survival Rates of Short Dental Implants (<10 mm) with Ungrafted Transcrestal Sinus Floor Elevation Procedures and Longer Implants (≥10 mm)

Objectives: Investigating whether or not the use of short dental implants (<10 mm) results in similar survival rates to longer implants (≥10 mm) in combination with transcrestal sinus lifting procedures without grafting.Materials and methods: Twenty partially edentulous patients with one or both maxillary posterior segments, treated in the time period between March 2014 and December 2016 with either short dental implants (group I) or had a preoperative transcrestal sinus floor elevation (TSFE) procedure without bone graft (group II), were retrospectively enrolled in this study.Patients were 15 females and 5 males; the mean age, at the time of implant placement, was 42.09 ± 6.96 years for group I and 39.22 ± 6.9 for group II, ranging between 30 years and 54 years.Based on preoperative periapical radiographs, the residual alveolar heights were judged to be less than 10 mm until 7 mm.Postoperatively, the amount of new radiopacity between the sinus floor and the alveolar crest of group II cases was then measured using a digital ruler from the mesial and distal surfaces of each implant.In total, 11 implants were placed in group I and 9 implants were placed in group II.Results: After a mean follow-up period of 31.9 ± 9.4 months for group I and 30.5 ± 6.13 for group II, with some implants up to 4 years in duty, a survival rate of 100% was reported for both groups.The mean bone level, for group II, at the implant placement was 8.58 ± 0.81 mm and, after 2.5 years, it was 10.8 ± 0.85 mm.Conclusion: Within the limitations of this retrospective clinical study, the results confirmed the reliability of both, the TSFE without grafting procedure and the use of short dental implants in posterior maxillary edentulous spaces of reduced heights.