5- to 15-Year Survival of Immediately Loaded Implants in Fully Edentulous Maxillae: A Multilevel Analysis in a Retrospective Cohort Study.

PURPOSE: Although immediate-loading implant (ILI) treatment is a general treatment strategy for fully edentulous maxillae, long-term evidence is required. The purpose of this study was to evaluate the long-term clinical results of, and risk factors for, ILI treatment in fully edentulous maxillae. MATERIALS AND METHODS: ILI treatments of maxillae using 526 implants in 117 patients were reviewed retrospectively. The longest and mean observation periods were 15 years and 9.2 years, respectively. Kaplan-Meier survival curve analysis, log-rank tests, and multilevel mixed-effects parametric survival analysis were used for statistical analyses. RESULTS: Overall, 38 of 526 implants failed in 23 patients, and the estimated 15-year cumulative implant-level and patient-level survival rates were 90.7% and 73.7%, respectively. The cumulative implant survival rate was significantly higher in female patients than in male patients. Sex, implant length, and implant diameter were significantly associated with implant survival. CONCLUSION: ILI treatment of completely edentulous maxillae demonstrated viable long-term clinical outcomes. Male sex, shorter implant length, and narrow implant diameter negatively affected implant survival. Int J Oral Maxillofac Implants 2023;38:516-522. doi: 10.11607/jomi.10310.

Effects of alumina airborne-particle abrasion on the surface properties of CAD/CAM composites and bond strength to resin cement.

The purpose of this study is to clarify physical and chemical changes in surfaces of CAD/CAM composites caused by alumina airborne-particle abrasion and its effect on adhesive bonding. Our study involved three dispersed filler (DF)-based and a polymer-infiltrated ceramic network (PICN)-based CAD/CAM composites. Changes in the surface morphologies of the composites were examined, and surface free energy (SFE) analysis was performed based on Owens-Wendt theory. The influence of the abrasion on the bond strengths of CAD/CAM composites to the resin cement was characterized by shear bond strength (SBS) test. The abrasion increased the roughness of the composites. The SFE analysis showed that the abrasion significantly increased the dispersive component but decreased the polar component of the SFE associated with the DF-based composites, while no change occurred for those of the PICN-based composite. The abrasion slightly improved the SBSs for the DF-based composites but not that of the PICN-based composite.

Correlation between microstructure of CAD/CAM composites and the silanization effect on adhesive bonding.

The aim of this study was to investigate the relationship between the microstructure of a CAD/CAM composite and the silanization effect on adhesive bonding, using surface free energy (SFE) analysis. Six commercial CAD/CAM composites, as well as control samples of two glass-ceramics and a resin, were investigated. The samples were characterized by morphological observations and SFE analysis. The bonding characteristics of the samples with the resin-cement were evaluated according to the silanization effect, which was determined from the ratio between the shear-bond strengths for the sample groups, with and without a silane-primer application. The composites were classified into two groups in terms of their microstructure; ENAMIC exhibits a polymer-infiltrated-ceramic-network (PICN) structure, while the other composites have a dispersed-filler (DF) structure. The dispersive component of the SFE was significantly lower in the PICN composite than in the DF composites. On the other hand, the polar component of the SFE was significantly higher in the PICN composite than in the DF composites. These SFE components were similar to those of glass-ceramics for the PICN composite and to those of the resin for the DF composites. The silanization effect increased linearly with the polar component or with a decrease in the dispersive component. Additionally, the silanization effect increased with the inorganic content. As a result, the silanization effect was found to be the highest for the PICN structure of ENAMIC. The results revealed that the silanization effect on the adhesive bonding is more effective for a PICN composite than for a DF composite.