Background: Long‐term data (>10 years) concerning the survival and success rates of implants and implant‐supported prostheses are scarce.Purpose: The present investigation represents one of the first studies on dental implants covering an observational period of 25 years.Materials and methods: This study presents the results obtained in 26 patients with 75 implants who participated over a 23‐ to 28‐year period in a supportive implant therapy (SIT) program at a private dental practice. We extracted existing data from the patients' files (pocket depths [PDs], bleeding on probing [BoP], radiographic peri‐implant bone loss, and survival rates of the implant‐supported prostheses).Results: After 25 years, the SIT‐compliant patients' implants had a survival rate of 95% (prostheses: 88%). The mean peri‐implant probing depth was 3.69 mm (median: 3.33; SD: 1.06; range: 2‐8.33). The mean peri‐implant bone level was 1.84 mm (median: 1.82; SD: 1.20; range: −0.97‐5.2). Finally, the prevalence (moment of last consultation) and incidence (during the entire observational period) of peri‐implantitis were 7% and 30%, respectively.Conclusions: Under SIT conditions, clinicians may expect survival rates for implant‐supported prostheses of >80%. Most implants (60%) did not develop signs of peri‐implantitis over a 25‐year period.

Aim: Few data are available regarding the long‐term impact of supportive implant therapy (SIT) on peri‐implant diseases. We present long‐term results on the possible effects of SIT on the peri‐implant tissues.Material and methods: In a private practice, 50 consecutive patients with 101 implants had attended an SIT programme for >6 years (SIT group). A second consecutive group comprised patients without SIT compliance (C group). We assessed pocket probing depth (PPD), bleeding on probing (BOP), bone loss (BL) and implant hygiene (QHI). Correlations between SIT compliance and the prevalence of peri‐implant diseases were evaluated statistically.Results: The inclusion criteria were met by 48 patients with 98 implants (SIT group) and 43 patients with 121 implants (C group). SIT group: Mucositis rate 30%; mean PPD 3.76 ± 0.86 mm; bone loss 1.02 ± 0.85 mm, peri‐implantitis rate 4%. C group: Mucositis rate 68%; mean PPD 4.07 ± 1.18 mm; bone loss 1.53 ± 1.46 mm; and peri‐implantitis rate 17%. Significant associations were found between SIT compliance and reduced peri‐implant mucositis (p = .019), reduced highest PPD (p = .038) and peri‐implantitis rates (p = .027).Conclusions: Patients under SIT were associated with lower incidence of peri‐implant diseases. Patients without regular maintenance might exhibit a 4.25‐fold increased risk for peri‐implantitis. Therefore, SIT programmes should be considered essential.