A cohort study on short mini‐implants for mandibular overdentures compared to those of standard length

Abstract Objectives To assess peri‐implant bone level, survival and success rates of short (6 or 8 mm long) one‐piece mini‐implants (MDIs) in edentulous patients with extremely resorbed alveolar ridge (interforaminal height <10 mm) rehabilitated with mandibular implant overdentures and to compare them with patients having standard length MDIs in 1‐year prospective clinical study. Material and methods The Short MDI group consisted of 28 participants with interforaminal height ≤10 mm. Implants being, both, short and slim (short MDIs: 6 or 8 mm long, 2 or 2.5 mm wide) were inserted. The Standard‐MDI group included 35 participants (interforaminal height >13 mm) who received standard length MDIs (10–14 mm long, 2 or 2.5 mm wide). Primary outcomes were assessments of MDI peri‐implant bone level, survival and success rates; secondary outcomes were assessments of peri‐implant tissue, oral hygiene, and prosthodontic maintenance. Results The Short MDI group had mean marginal bone loss (MBL) of 0.26 ± 0.35 mm, 6.4% of failure, and 92.6% of, both, success and survival rates. The Standard‐MDI group had mean MBL of 0.34 ± 0.40 mm, 5% of failure, 95% of survival, and 94.3% success. There were no significant differences in MBL ( p = .420), survival ( p = .414), and success ( p = .571) between the groups. The Short MDI group had significantly less plaque ( p = .001) and bleeding on probing ( p < .001). Conclusion Within the limitations of this study, short MDIs (6 or 8 mm long) in extremely atrophied mandibles (interforaminal height <10 mm) showed good clinical results in the first year of function.