Changes of the atrophic maxillary alveolar bone and treatment success 10 years after placement of implants simultaneously with transalveolar sinus floor elevation; A retrospective analysis

IKSSZ ePOSTER CLINICAL RESEARCH – PERI-IMPLANT BIOLOGY

Background: There are few data on the morphological changes of the atrophic maxillary alveolar bone following to placement of dental implants simultaneously with transalveolar sinus floor elevation. In addition, there is only few data (10 years plus) on the long-term outcome of implants after placement according to Summer's osteotome technique [OSFE]. Clinical and radiographical reports have shown that long-term survival of implants can be expected after OSFE.

Aim/Hypothesis: This practice-based retrospective report evaluates long-term survival and long-term success, respectively. The amount of peri-implant former atrophic bone is increasing over time, as healthy conditions (absence of peri-implantitis) can be obtained.

Materials and Methods: 38 patients, 32 of them with a history of treated periodontitis, received at least one screw-type implant, where OSFE (Summers, 1994) was performed. Recipient sites showed reduced bone height with less than 8 mm (average 6.60 mm) in radiographical height. Elevated sinus floor segments were grafted with DBBM. A total of 55 implants with cemented single crowns on customized abutments were followed over 10 years. All patients participated in a maintenance program. Clinical and radiographical data were collected at time of insertion (T0), loading (T1), one year after loading (T2) and at various times during the functional period, finally after at least ten years (T3). Implant success was determined according to the criteria by Misch et al. (2008). Changes in levels of alveolar bone height [AH] were measured by analysis of peri-apical x-rays produced from edentulous ridge at time of implant placement [AH-E] and at follow-up after at least 10 years of implant in place [AH-P].

Results: Overall implant survival rate was 98.2% (N = 54/55). The only lost implant was one of those with less than 3.5 mm of residual bone height at insertion. All other implants showed radiographic osseointegration around the implant apex at the time of T3 (10y+) data collection. Overall alveolar bone height increased, amounting to 0.78 ± SD 1.60 mm (min -3.8/max + 4.8 mm). Regarding implant success, 61.8% of implants (N = 34/55) were in ‘optimum success’, while 18.2% (N = 10/55) showed ‘satisfactory survival’. Due to radiographic bone loss, 10 implants (18.2%) were classified as ‘compromised survival’.

Peri-implant disease was observed in 30.2% of the implants (N = 17/55; mucositis (N = 6)/peri-implantitis (N = 11)) and was non-surgically treated.

Alveolar bone height gain over 10 years [Δ AH-E – AH-P] at implants showing optimum success / satisfactory survival (N = 44/55; 80%) was measured 0.96 ± SD: 1.27 mm (min -1.3/max. +3.7) on average.

Conclusions and Clinical Implications: The findings of this retrospective analysis reveal gain of peri-implant bone and excellent long-term implant survival and long-term outcome after transalveolar sinus floor elevation using DBBM in anatomic situations with limited residual alveolar bone height.

Acknowledgements: The authors like to thank Prof. Dr. Dr. S. Jepsen, Dr. C. Tietmann and Dr. S. Wenzel for their contribution

Keywords: Peri-implant bone, Transalveolar sinus floor elevation, Long-term implant function, Alveolar bone height, Peri-implant disease