SIGNIFICANCE This study did not identify clear advantages of using the first generation of ormocer-based fillings rather than conventional composites .
OBJECTIVES In-vitro experiments on  ormocers ( ORganically MOdified CERamics )  have provided controversial results .
Consequently , the objectives of this meta- analysis were to ( 1 ) compare clinical performances of first generation ormocers versus conventional composite restorations  , ( 2 ) explore the influence of various clinical factors and the impact of the quality of studies on published results .
Clinical performance of ormocer, nanofilled, and nanoceramic resin composites in Class I and Class II restorations: a three-year evaluation.
PURPOSE This prospect i ve long-term clinical trial evaluated and compared the three-year clinical performance of an ormocer , a nanofilled , and a nanoceramic resin composite with that of a microhybrid composite placed in Class I and Class II cavities . METHODS Forty patients , each with four Class I and II restorations under occlusion , were enrolled in this study . A total of 160 restorations were placed , 25 % for each material , as follows : an ormocer-based composite , Admira ; a nanofilled resin composite , Filtek Supreme XT ; a nanoceramic resin composite , Ceram X ; and a microhybrid resin composite , Tetric Ceram . A single operator placed all restorations according to the manufacturers ' instructions . Immediately after placement the restorations were finished/polished . Clinical evaluation was performed at baseline and at yearly intervals after placement by two other independent examiners using modified US Public Health Service ( USPHS ) criteria . The changes in the USPHS parameters during the three-year period were analyzed with the Friedman test . Comparison of the baseline scores with those at the recall visits was made using the Wilcoxon signed rank test . The level of significance was set at p < 0.05 . RESULTS All material s showed only minor changes , and no differences were detected between their performance at baseline and after three years . Only two ormocer , one nanofilled , and one microhybrid restorations in molars failed because of loss of retention . Regarding the clinical performance , there were no statistically significant differences among the material s used ( p>0.05 ) . CONCLUSIONS The ormocer , nanofilled , and nanoceramic composites provided acceptable clinical performance over a three-year period
SIGNIFICANCE This study did not identify clear advantages of using the first generation of ormocer-based fillings rather than conventional composites .
OBJECTIVES In-vitro experiments on  ormocers ( ORganically MOdified CERamics )  have provided controversial results .
Consequently , the objectives of this meta- analysis were to ( 1 ) compare clinical performances of first generation ormocers versus conventional composite restorations  , ( 2 ) explore the influence of various clinical factors and the impact of the quality of studies on published results .