Clinical esthetic comparison between monolithic high-translucency multilayer zirconia and traditional veneered zirconia for single implant restoration in maxillary esthetic areas: Prosthetic and patient-centered outcomes

BACKGROUND/PURPOSE: Clinical esthetic evidence for the performance of monolithic high-translucency multilayer zirconia is lacking. The aim of this study was to compare monolithic high-translucency multilayer zirconia with traditional veneered zirconia in clinical situation. MATERIAL AND METHODS: A total of 30 participants who were provided with both monolithic zirconia crowns (Group 1) and traditional veneered crowns (Group 2) for single implant restoration in maxillary esthetic areas were enrolled. Patients' subjective outcome (Visual Analog Scale, VAS) were recorded. Photos were taken and then evaluated by 9 evaluators with Pink and White Esthetic Score (WES). Wilcoxon signed rank test was used for comparison between Group 1 and Group 2 in VAS, WES and five variables in WES. Kendall's coefficient of concordance test was used to calculate inter-rater reliability of WES variables. Spearman correlation was used to analyze association between patients' outcome and evaluators' scores. RESULTS: There was no significant difference in patients' subjective outcome between monolithic zirconia and traditional veneered crowns: overall VAS were 9.0 (8.0–9.0) and 9.0 (8.5–9.5), respectively (P > 0.05). However, in professional view, significant difference between Group 1 and Group 2 in WES was observed: 7.5 (6.0–8.0) and 8.0 (6.5–8.5), respectively (P < 0.05). Kendall's test showed, among WES variables, translucency demonstrated the highest agreement. Professionally reported evaluations did not correlate with patient-reported outcomes (Spearman correlation were 0.246 and 0.224 for Group 1 and Group 2, respectively). CONCLUSION: Within the limitation of this study, it can be concluded that monolithic high-translucency multilayer zirconia restoration might be a treatment modality.