RESUMO
OBJECTIVES: To investigate the effect of defined versus undefined periodontal maintenance after implant therapy on the prevalence of peri-implant complications. MATERIAL AND METHODS: Two hundred patients who underwent dental implant therapy in the National Dental Centre Singapore (NDCS) from 2005 to 2012 were recruited. One hundred patients had regular periodontal maintenance (defined maintenance programme group, DMP), and the other 100 patients had no documentation of periodontal maintenance (undefined maintenance programme group, UMP). Full-mouth bleeding scores (FMBS), periodontal probing depths (PPD) and peri-implant probing depths (PiPD) were evaluated within 6 months of prostheses delivery (T0 ) and at re-examination (T1 ). Peri-implant bone level changes were analysed radiographically. RESULTS: The mean follow-up time was 6.8 years. Five out of 289 implants were lost (cumulative survival rate = 98.3%). 6.0% of DMP patients and 20.0% of UMP patients had peri-implantitis (p = .003). Peri-implantitis was defined as bleeding on probing, increase in PiPD and peri-implant bone loss ≥ 0.5 mm. At the implant level, 4.0% of the DMP group implants and 17.2% of the UMP group implants were diagnosed with peri-implantitis (p = .0003). One implant in the DMP group and 13 implants in the UMP group had bone loss ≥ 2 mm (p < .0001). Multivariate regression showed that absence of regular maintenance (OR = 0.24, p = .003) was significantly associated with peri-implantitis. CONCLUSIONS: Regular periodontal maintenance was associated with a lower prevalence of peri-implantitis and peri-implant bone loss. Patients with treated periodontitis without regular maintenance after implant placement were at higher risk for developing peri-implantitis.