Five-year outcome of a retrospective cohort study comparing smokers vs. Nonsmokers with full-arch mandibular implant-supported rehabilitation using the All-on-4 concept

Abstract

The aim of this study was to compare the 5-year outcome of full-arch mandibular fixed prosthetic rehabilitation using the All-on-4 concept in smoking and nonsmoking patients. This retrospective cohort study included 200 patients (n = 100 smokers, n = 100 nonsmokers), 119 women and 81 men, with an average age of 53.7 years, rehabilitated in immediate function with 800 implants. Implant cumulative survival rate estimation (Kaplan-Meier with log-rank test) and marginal bone resorption (MBR) at 5 years (Mann-Whitney test) were compared between both groups. Multivariable analysis was used to investigate potential risk indicators for MBR ≥ 2.8 mm at 5 years. Nine patients (4.5%) were lost to follow-up. Four patients lost eight implants, specifically one nonsmoking patient (n = 1 implant) and three smoking patients (n = 7 implants), resulting in a cumulative survival rate estimation of 99.0% and 96.9% for nonsmokers and smokers, respectively (P = 0.296). The average (standard deviation) MBR at 5 years was 1.68 mm (0.76 mm) and 1.98 mm (1.02 mm) for nonsmokers and smokers, respectively (P =0.045). Smoking (odds ratio = 2.92) was the only risk indicator significantly associated with MBR ≥ 2.8 mm in multivariable analysis. Smoking should not be an absolute contraindication for rehabilitation of the edentulous mandible through the All-on-4 concept; however, smoking habits were significantly associated with MBR ≥ 2.8 mm.