The Effect of Core and Veneering Design on the Optical Properties of Polyether Ether Ketone

This study evaluated the clinical performance of direct restorations made of nanofilled and microhybrid resin composites in endodontically treated teeth. Twenty patients (11 males, 9 females; mean age: 34.2±10) that met the inclusion criteria received a total of 48 restorations. After employing etch-and-rinse adhesive system, one dentist placed all restorations using either a nanofilled (Filtek Ultimate) or microhybrid (Filtek Z250) resin composite. The restorations were clinically reviewed at baseline, 6 months, and up to 2 years using the modified United States Public Health Service (USPHS) criteria. The changes were analyzed using the McNemar test and marginal homogeneity tests (p<0.05). The mean observation period was 17.4 months. With respect to color match, marginal adaptation, secondary caries, and surface texture, no significant differences were found between the two restorative materials (p>0.05). Most restorations yielded alpha or bravo scores with respect to the evaluation criteria. Five restorations failed due to chipping up to 2 years (1 microhybrid at 6 m, and 3 at 2 years; 1 nanofilled at 2 y) and were repaired. One complete replacement and one extraction due to endodontic complications were needed for 2 microhybrid resin group at 2 years.