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Survival of porcelain laminate veneers with different degrees of dentin exposure: 2-year clinical results.

PURPOSE
To evaluate the clinical performance of porcelain laminate veneers (PLVs) after 2 years.


MATERIALS AND METHODS
Twenty-eight patients were treated with 125 PLVs. The experimental variables were preparation design (incisal overlap [IO] and incisal bevel [IB]) and adhesion surface (enamel [E], enamel with minimal dentin exposure [MDE], and enamel with severe dentin exposure (SDE)]. Marginal adaptation, marginal discoloration, secondary caries, postoperative sensitivity, and patient satisfaction were assessed according to the modified United States Public Health Service criteria. Each restoration was examined for fractures and debonding. In addition, gingival tissue health by gingival plaque, bleeding, and recession was recorded. An experienced clinician evaluated the restorations at baseline and after 6, 12, and 24 months, and survival rates evaluating relative and absolute failures were calculated (p = 0.05).


RESULTS
Eleven (8.8%) veneers failed, and the overall cumulative survival rate was 91.2% after 2 years of followup. IB and IO preparation designs exhibited survival rates of 94% and 85.7%, respectively, but this difference was not statistically significant (p > 0.05). PLVs bonded to SDE were more likely to fail than those bonded to E and MDE (p < 0.05). There was no significant difference between the failure rate of PLVs bonded to E and those bonded to MDE (p > 0.05).


CONCLUSIONS
PLVs have high survival rates when bonded to enamel only, as well as to enamel with minimal dentin exposure. However, extensive dentin exposure should be avoided during the preparation.