Factors affecting peri‐implant bone resorption in four Implant supported mandibular full‐arch restorations: a 3‐year prospective study

Abstract Background Peri‐implant marginal bone‐level ( MBL ) alteration represents one of the parameters included in the criteria for determining implant health. Objective Factors affecting peri‐implant MBL alteration for 4‐implant‐supported fixed mandibular prostheses (4‐ ISFMP ) were assessed. Material & Methods A 3‐year prospective, cohort study was conducted on 44 mandibularly edentulous patients treated with 4‐ ISFMP . Peri‐implant MBL alteration was evaluated radiographically at the 12‐, 24‐ and 36‐month follow‐ups considering to patient‐related risk factors [age, gender, diabetes mellitus, smoking, cardiovascular disease ( CVD ), rheumatic disorders ( RD )] and implant/prosthesis‐related features (implant location, keratinized gingiva, denture cantilever length, prosthesis supporting zone, opposing dentition) as well as to peri‐implant biological parameters (plaque‐, bleeding‐, calculus index). Results 148/176 implants (37 patients, drop‐out: 15%) were followed for 3 years showing significant ( p < 0.001) annual differences of MBL alterations over time. The univariate analysis demonstrated differences of MBL alterations for smokers ( p = 0.014), for patients with CVD ( p = 0.001) and RD ( p = 0.011). In the 3‐year multivariate analysis, MBL alteration was influenced by time ( p < 0.001) and showed relationship with risk factors as smoking ( p < 0.002; OR = 18.965), CVD ( p < 0.021; OR = 5.172), RD ( p < 0.006; OR = 50.171) and plaque‐index ( p = 0.034; OR = 3.252). Conclusions Although peri‐implant MBL alteration increased annually, significant odds ratios, were found for patients‐related risk factors identifying them potentiating the alterations.