Marginal bone height changes around maxillary and mandibular implants supportin g All on four fixed detachable prosthesis. One-year prospective study

Abstract

Purpose of the study: The aim of the present study was to investigate the marginal boneheight changes around maxillary and mandibular implants supporting all on four fixed detachableprosthesis after one year follow upMaterials and methods: six completely edentulous patients (4 males and 2 females) receivednew conventional maxillary and mandibular dentures and were asked to wear them for 3 monthsto enhance adaptation. Four implants were inserted in the maxillary (between the nasal sinuses)and mandibular (between the mental foramina) arch of each patient according to the All On fourprotocol. Implants were immediately loaded with provisional dentures after connection of multiunitabutments, and after 3 months of osseointegration temporary dentures were replaced by fixedceramo-metal prosthesis. Vertical marginal bone loss (VBL) was evaluated at the time of fixedhybrid prosthesis insertion, 6 and 12 months later using standardized peri-apical radiographs.Results: Maxillary anterior implants recorded significant higher VBL (P ≤ 0.005) thanmandibular implants after 6 months and 12 months of prosthesis insertion. Also, the maxillaryanterior implants showed significant VBL (P ≤ 0.005) than the posterior implants. For the posteriorimplants, no significant difference in VBL was observed between the maxillary and mandibularimplants. For the mandibular implants, no significant difference in VBL between the anterior andposterior implants was observed.Conclusion: Within the limitation of this short-term study, taking the small patient cohort intoaccount, it could be concluded that maxillary anterior implants supporting all on four fixed hybridprosthesis are at increased risk for marginal bone loss compared to maxillary posterior implants ormandibular implants.