Short and ultra-short (<6-mm) locking-taper implants supporting single crowns in posterior areas (part II): A 5-year retrospective study on periodontally healthy patients and patients with a history of periodontitis

Background: Short and ultra-short implants implants supporting single crowns seem to demonstrate high percentages of survival and stable marginal bone levels at a mid-term follow-up. Nevertheless, insurgence of peri-implant complications still represents a critical issue, especially for patients with history of periodontitis.

Purpose: The aim of this retrospective study was to evaluate implant survival, marginal bone loss and peri-implant complications in 333 short and ultra-short implants, placed in periodontally healthy patients and patients with a history of periodontitis.

Materials and methods: Implants were placed in the maxillary and mandibular posterior regions of 142 patients with (PP) and without (NPP) a history of periodontitis. Clinical and radiographic examinations were performed at 5-year recall appointments.

Results: Implants respectively placed in PP and NPP were: 35.68% and 42.50% in 8.0 mm-length group, 33.33% and 36.67% in 6.0 mm-length group, and 30.99% and 20.83% in 5.0 mm-length group. Implant-based survival after 5 years of follow-up was 95.77% for PP and 96.67% for NPP (p = 0.77). Regarding crestal bone level variations, average crestal bone loss was statistically different (p = 0.04) among PP (0.74 mm) and NPP (0.61 mm). Implants presenting signs of mucositis were 6.86% in PP and 7.76% in NPP (p = 0.76). Setting the threshold for excessive bone loss at 1 mm after 60 months, peri-implantitis prevalence was 7.84% in PP and 2.59% in NPP (p = 0.08). Overall implant success was 92.16% and 97.41%, respectively, for PP and NPP.

Conclusions: Under strict maintenance program, five-year outcomes suggest that short and ultra-short locking-taper implants can be successfully restored with single crowns in the posterior jaws both in PP and NPP.