Conclusions The present systematic review and meta- analysis indicate similar clinical performances of bulk-fill and conventional resin composites over a follow-up period of 12 to 72 months .
Clinical significance Based on the results of this study , the bulk-fill resin composites could be an alternative for direct restorations in posterior teeth .
Objectives The purpose of this systematic review was to compare the clinical performance of bulk-fill resin composites with conventional resin composites used for direct restorations of posterior teeth .
The research question was “ Do bulk-fill resin composites have a clinical performance comparable to conventional resin composites in posterior restorations ? ”
A six-year prospective randomized study of a nano-hybrid and a conventional hybrid resin composite in Class II restorations.
OBJECTIVE The objective of this 6 year prospect i ve r and omized equivalence trial was to evaluate the long-term clinical performance of a new nano-hybrid resin composite ( RC ) in Class II restorations in an intraindividual comparison with its well-established conventional hybrid RC predecessor . METHODS Each of 52 participants received at least two , as similar as possible , Class II restorations .  The cavities were chosen at r and om to be restored with an experimental nano-hybrid RC ( Exite/Tetric EvoCeram ( TEC ) ; n=61 ) and a conventional hybrid RC ( Exite/Tetric Ceram ( TC ) ; n=61 ) . The restorations were evaluated with slightly modified USPHS criteria at baseline and then annually during 6 years . RESULTS Two patient drop outs with 4 restorations ( 2TEC , 2TC ) were registered during the follow-up . A prediction of the caries risk showed that 16 of the evaluated 52 patients were considered as high risk patients . Eight TEC ( 2 P , 6 M ) and 6 TC ( 2P , 4 M ) restorations failed during the 6 years . The main reason of failure was secondary caries ( 43 % ; including the failure fracture+ secondary caries it increases to 57.1 % ) . 63 % of the recurrent caries lesions were found in high caries risk participants . The overall success rate at six years was 88.1 % . No statistical significant difference was found in the overall survival rate between the two investigated RC . SIGNIFICANCE The nano-hybrid RC showed good clinical performance during the 6 year evaluation , comparable to the well-established conventional hybrid RC
Conclusions The present systematic review and meta- analysis indicate similar clinical performances of bulk-fill and conventional resin composites over a follow-up period of 12 to 72 months .
Clinical significance Based on the results of this study , the bulk-fill resin composites could be an alternative for direct restorations in posterior teeth .
Objectives The purpose of this systematic review was to compare the clinical performance of bulk-fill resin composites with conventional resin composites used for direct restorations of posterior teeth .
The research question was “ Do bulk-fill resin composites have a clinical performance comparable to conventional resin composites in posterior restorations ? ”