Clinical evaluation of porcelain‐veneered zirconia crowns with 3D‐printed textured cores: A preliminary randomized clinical trial

Abstract

Abstract Purpose Porcelain‐veneered zirconia crowns (PVZCs) provide the opacity required to mask discolored substrates and translucency needed for a natural appearance. Although in vitro studies have demonstrated that three‑dimensionally (3D)‑printed textures on zirconia cores can strengthen the zirconia–porcelain bond and thereby may reduce chipping incidence of PVZCs, their clinical performance remains to be verified. The purpose of this randomized clinical trial was to preliminarily investigate the influence of 3D‐printed textures of zirconia cores on the clinical performance of PVZCs, particularly the influence on esthetic properties. Materials and Methods Sixteen participants requiring PVZCs for anterior tooth defects to mask severely discolored abutment teeth or metal post‐and‐core restorations were randomly allocated to two groups (eight participants per group). All zirconia cores were 3D‐printed using advanced customized jetting (ACJ) technology and veneered with feldspathic porcelain. Cores in the experimental group were fabricated with 200 µm high textures on the veneering surface, whereas cores in the control group were fabricated smooth; airborne‐particle abrasion (APA) was applied to both surfaces of the control cores and to the internal surface only of the textured cores. Color matching against target teeth was assessed using a spectrophotometer. Clinical evaluations were performed at baseline and at the 1‐, 3‐, and 6‐month follow‐ups and included assessment of color match, translucency, chipping/fracture, and participant satisfaction. Color differences (Δ E 00 ) were compared between groups by using independent‐samples t tests, and the repeatedly measured clinical ratings were analyzed by using linear mixed‐effects models ( α = 0.05). Results No statistically significant differences in Δ E 00 were found between the groups in any evaluated region, and no significant effects of group, time, or their interaction were found for color match, translucency, or participant satisfaction ( p > 0.05). No chipping or fracture occurred in either group, and participant satisfaction remained high in both groups. The mean Δ E 00 values ranged from 2.52 to 3.54 across regions and groups. Conclusions Over a 6‐month clinical evaluation, PVZCs with 3D‐printed textured cores showed esthetic and clinical performance comparable with that of air‐abraded nontextured cores. These findings are preliminary and require confirmation in studies with larger samples and longer follow‐up.