Late implant loss and complications of one-step implant therapy in severely atrophic posterior maxilla.

BACKGROUND/PURPOSE: Successful long-term outcomes of one-step implant placement in the atrophic maxilla have rarely been reported. This retrospective study aimed to evaluate the long-term efficacy of the one-step lateral sinus floor elevation and simultaneous implant placement (LSFESI) in severely atrophic posterior maxilla, and to identify the risk factors for marginal bone loss (MBL) and late implant failure (LIF). MATERIALS AND METHODS: Clinical data were obtained from Taipei Tzu Chi Hospital. One-step, non-submerged LSFESI was performed at sites with a remaining bone height (RBH) < 5 mm and an insertion torque > 15 N. The clinical and radiographic outcomes, including MBL and LIF, were assessed. The effects of patient- and implant-related factors on MBL were assessed using Generalized Estimating Equation to account for the clustering of multiple implants within the same patient. Chi-square or Fisher's exact tests were used to determine significant differences in the distribution of variables between patients with and without LIF. RESULTS: A total of 122 implants were placed in 60 patients across 73 sinuses to support fixed prosthetic reconstructions. The mean duration was 10 years. Implant survival rates were significant associated with several factors, including keratinized tissue (KT) < 2 mm, poor oral hygiene (OH), the presence of complications, and RBH. The overall LIF rate was 12.3 %. Female, poor OH, KT < 2 mm, and sinus perforation in combination with either sinus infection or infection of adjacent teeth had greater incidence of LIF. CONCLUSION: This study demonstrated that one-step LSFESI can be a predictable approach with favorable long-term outcomes.