Incidence of peri-implant disease in patients with maxillary overdentures during a 10-year follow-up

BWC3Q ePOSTER CLINICAL RESEARCH – PERI-IMPLANT BIOLOGY

Background: Recent research on maxillary overdenture therapy shows satisfying long-term results, but studies fail to report on peri-implant disease. Prevalence of peri-implant mucositis and peri-implantitis on a patient level has been estimated to range from 43-47% and 20-22% respectively, but the incidence, defined as the number of new cases per population at risk, is less clear. There is a need for prospective longitudinal data to clarify the incidence of peri-implant disease.

Aim/Hypothesis: To assess the incidence of peri-implant mucositis and peri-implantitis in fully edentulous patients rehabilitated with a maxillary implant overdenture during a 10-year follow up period.

Materials and Methods: 116 edentulous patients (580 implants) with maxillary implant overdentures participating in two randomised controlled clinical trials were included. At baseline, patients were at least 18 years old, fully edentulous for at least one year, had not received previous implant treatment in the maxilla, were NO-smoking and had no medical impediments for surgical treatment. Peri-implant mucositis was defined as bleeding on probing and/or suppuration with radiographic bone loss < 2 mm. Peri-implantitis was defined as bleeding on probing and/or suppuration with radiographic bone loss ≥ 2 mm. Data on plaque, calculus, gingival inflammation, bleeding on probing and pocket probing depth were assessed at 5 (T5) and 10 (T10) years of functional loading. Radiographic bone loss was assessed at baseline, T5 and T10 and was reported in frequency distributions. Peri-implant mucositis and peri-implantitis were calculated at patient and at implant level.

Results: After 5 years, 10 patients (50 implants) were lost to follow-up and one implant had been lost in the first year after implant placement. After 10 years, an additional 26 patient (134 implants) were lost to follow-up and five additional implants in two patients had been lost due to severe peri-implantitis. 5- and 10 years implant survival were 99.7% and 98.8%, respectively. Median scores for plaque, calculus, gingiva, bleeding were low throughout the study period. Mean probing depth was 4.0 ± 1.1 mm at T5 and 4.3 ± 1.2 mm at T10. Mean peri-implant bone loss was 0.42 ± 0.61 mm at T5 and 0.44 ± 0.78 mm at T10. The incidence of peri-implant mucositis at patient level was 52.8% at T5 and 58.2% at T10. Incidence of peri-implantitis at patient level was 6.6% at T5 and 8.8% at T10.

Conclusions and Clinical Implications: The incidence of peri-implant mucositis in fully edentulous patients treated with implant retained maxillary overdentures is comparable to estimated mean prevalence in other studies. The incidence of peri-implantitis and implant loss due to peri-implant infections in these patients is lower than other studies. Maintenance following a standardised protocol may have contributed to the low incidence.

Keywords: Dental implants, Edentulous, Maxilla, Overdenture, Peri-implant Disease