Work

Long-Term Aesthetic Performance of Freehand Direct Anterior Composite Resin Restorations: A Systematic Review and Meta-Analysis of Colour Alteration, Marginal Discolouration, and Surface-Quality Deterioration

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: Background: Freehand direct composite resin veneers offer a minimally invasive approach for managing aesthetic alterations in anterior teeth; however, their long-term colour alteration and surface performance remain uncertain. This systematic review evaluated colour alteration, marginal discolouration, and surface-quality deterioration after at least 24 months of clinical service. Methods: MEDLINE/PubMed, Embase, Web of Science, Scopus, the Cochrane Library, and ClinicalTrials.gov were searched. Randomised and non-randomised trials and longitudinal clinical studies evaluating freehand direct anterior composite restorations were eligible. Risk of bias was assessed using RoB 2 and the JBI cohort checklist. Single-arm proportions were pooled separately using random-effects models with Freeman–Tukey transformation. Logit-REML models, binomial-normal generalised linear mixed models, Hartung–Knapp adjustments, leave-one-out analyses, and influence diagnostics were used as sensitivity analyses. Results: Eight studies were included. Colour alteration was evaluated in 893 restorations, with a pooled proportion of 14% (95% CI: 5–26%; I2 = 95.0%). Marginal discolouration involved 566 restorations and yielded a pooled proportion of 21% (95% CI: 10–34%; I2 = 91.8%). Surface-quality deterioration was assessed in 896 restorations, with a pooled proportion of 21% (95% CI: 9–35%; I2 = 95.6%). GLMM estimates were 11%, 19%, and 18%, respectively. Hartung–Knapp and leave-one-out analyses produced compatible results, although prediction intervals were wide. No study materially altered the overall interpretation. Conclusions: The pooled proportions of recorded aesthetic deterioration were 14% for colour alteration, 21% for marginal discolouration, and 21% for surface-quality deterioration. However, between-study heterogeneity was substantial, and prediction intervals were wide (0–63%, 0–68%, and 0–74%, respectively), indicating considerable variability in the outcomes expected across clinical settings. Absence of recorded deterioration should not be interpreted as equivalent to overall aesthetic success or clinical acceptability. Accordingly, the pooled estimates should be interpreted cautiously and primarily as average estimates across heterogeneous clinical settings.

Source: Dentistry Journal

DOI: 10.3390/dj14100633