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4-year clinical performance and survival analysis of Class I and II compomer restorations in permanent teeth.

PURPOSE
To evaluate the 4-year clinical performance of the compomer Hytac in Class I and II cavities of permanent posterior teeth.


METHODS
53 compomer restorations were placed using the self-conditioning adhesive Hytac OSB (total bonding) without additional phosphoric acid-etching according to manufacturer's instructions. Restorations were rated (modified USPHS criteria) at baseline, after 6, 12, 18, 36 and 48 months in relation to tooth type (molar, premolar), size and class of cavities, isolation type (rubber dam, cotton rolls) and use of a calcium hydroxide liner. After 4 years, 39 restorations (73.6%) were available for examination. Statistical analysis was performed using Kaplan-Meier survival analysis with the logrank test and Fisher's exact test for the failure analysis.


RESULTS
After 4 years, the success rate was 84.6%, six restorations failed (15.4%). The average annual failure rate was therefore 3.85%. Loss of marginal integrity was the main cause of restoration failure. The probability that a restoration would remain clinically acceptable after 4 years was calculated to be 89% (Kaplan-Meier). No significant performance differences could be found between any of the restoration groups.