Three-year results of a randomized controlled clinical trial of the posterior composite QuiXfil in class I and II cavities.

This longitudinal randomized controlled clinical trial evaluated direct composite restorations for clinical acceptability as posterior restoratives in single- or multi-surface cavities and provides a survey of the 3-year results. Three dentists placed 46 QuiXfil (Xeno III) and 50 Tetric Ceram (Syntac Classic) composite restorations in stress-bearing class I and II cavities in first or second molars (43 adult patients). Clinical evaluation was performed at baseline and after 3 years by two other dentists using modified US Public Health Service criteria. At the last recall period, 40 QuiXfil and 46 Tetric Ceram restorations were assessed. A total of 92.5% of QuiXfil and 97.8% of Tetric Ceram posterior composites were assessed to be clinically excellent or acceptable with predominating alpha scores. Up to the 3-year recall, three QuiXfil restorations failed because of bulk fracture, partial tooth fracture, and postoperative symptoms. One Tetric Ceram restoration was lost due to problems with tooth integrity. No significant differences between both composites could be detected at 3 years for all evaluated clinical criteria (p > 0.05). The comparison of restoration performance with time within both groups yielded a significant increase in marginal discoloration (p = 0.007) and deterioration of marginal integrity (p = 0.029) for QuiXfil and significant increase in marginal discoloration (p = 0.009) for Tetric Ceram. However, both changes were mainly effects of scoring shifts from alpha to bravo. Clinical assessment of stress-bearing QuiXfil and Tetric Ceram posterior composite restorations exhibited for both materials good clinical results with predominating alpha scores.