Clinical performance of a hybrid resin composite with and without an intermediate layer of flowable resin composite: a 7-year evaluation.
OBJECTIVE
The objective of this prospective clinical follow up was to evaluate the long term clinical performance of a hybrid resin composite in Class II restorations with and without intermediate layer of flowable resin composite.


METHODS
Each participant received at least two, as similar as possible, Class II restorations of the hybrid resin composite. One resin composite restoration of each pair (59) was chosen at random to be restored with an intermediary layer with flowable resin composite. The other was restored without. The 118 restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 7 years.


RESULTS
Four drop outs were registered during the 7-year follow up (2 with and 2 without flowable) restorations. A prediction of the caries risk showed that 18 of the evaluated 46 patients were considered as high risk patients. Seventeen failures were observed, 8 in restorations with and 9 in restorations without an intermediate layer of flowable resin composite, resulting in a 14.9% failure rate after 7 years. The main reasons for failure were: fracture of resin composite (8), secondary caries (4) and cusp fracture (3). No statistical difference was seen between restorations restored with and without flowable layer.


CONCLUSIONS
The hybrid resin composite showed a good clinical performance during the 7-year evaluation. The use of flowable resin composite as an intermediate layer did not result in improved effectiveness of the Class II restorations.
van Dijken
Jan W V
JW
Department of Odontology, Dental Hygienist Education, Dental School Umeå, Faculty of Medicine, Umeå University, 901 87 Umeå, Sweden. jan.van.dijken@odont.umu.se
Pallesen
Ulla
U
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003731:Dental Caries / Q000150:complications; D003733:Dental Caries Susceptibility; D003743:Dental Enamel / Q000293:injuries; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D014082:Tooth Fractures / Q000150:complications; D055815:Young Adult
D003188:Composite Resins; D003764:Dental Materials; C420130:Excite cement; D008689:Methacrylates; C121818:Tetric ceram; C111840:flowable hybrid composite; C452226:tetric flow composite resin