Clinical assessment of direct composite veneer and indirect veneers using a minimally invasive preparation technique

The aim of this study was to compare and evaluate the clinical performance of direct composite veneers (DCVs), indirect composite veneers (ICVs), and ceramic veneers using a minimally invasive tooth preparation technique.

A total of 90 veneers were placed on the anterior teeth: DCVs (n = 30), ICVs (n = 30), and ceramic laminate veneers (n = 30). Tooth preparations were standardized using magnification (×3 loupes) and depth-marking burs. DCVs were applied using a multilayered stratification technique and finished with a composite polishing kit. ICVs were CAD-CAM fabricated using Gradia HIPS, while ceramic veneers were milled from IPS e.max CAD HT blocks and layered with nanofluorapatite ceramic. All restorations were cemented using adhesive protocols tailored to each material. The restorations were assessed at baseline, 3 months, 6 months, and 1 year using the modified United States Public Health Service criteria.

Data were analyzed using SPSS 23.0 with a significance level of P < 0.05. Fisher's exact test was used for comparing proportions, and Kaplan-Meier analysis assessed overall survival relative to observation time.

At 3, 6, and 12 months, marginal discoloration showed a statistically significant increase (total events: 8, 14, and 28; P < 0.001). No events were observed for caries or tooth fracture. Postoperative sensitivity occurred in three cases but was not statistically significant (P > 0.05). While fractured restorations showed no significant difference at 3 and 6 months, a significant increase was noted at 12 months (11 events; P = 0.02).

Indirect composite and ceramic veneers showed superior performance over DCVs in minimizing marginal discoloration, postoperative sensitivity, and restoration fractures.