Randomized 3-Year Follow-up of Posterior Bulk-Filled Resin Composite Restorations

Method: Each of 82 participants received 2 or 4, as similar as possible, Class II (104) or I (76) restorations, placed by 2 operators The cavities in the pairs were chosen at random to be restored with a nanohybrid RC (CeramX+)(CX) only or with a flowable bulk filling RC (SDR) covered with CX. The adhesive used in both groups was a 1-step SEA (Xeno V+). SDR was placed in 4mm layers and CX in 2 mm layers. Each layer was cured for 20s. The restorations were evaluated with slightly modified USPHS criteria at baseline, 1, 2 and 3 years.

Result: Two patient drop outs with 4 restorations (2SDR/CX, 2CX) were registered. Seven restorations failed (3.6%) during the 3 years, all Class II (4SDR/CX, 3 CX).  The reasons for failure was tooth fracture (2P, including 1 combined with secondary caries and 3M including 1 combined with RC fracture), caries (1M), composite fracture (1M). AFR for SDR/CX and CX was 1.2% and 1.0%, respectively (n.s. Friedman´s two way analysis of variance test).

Conclusion: The bulk filling technique showed good clinical performance during the 3 year evaluation, comparable to the nanohybrid-only restorations.
The study was supported by the county of Västerbotten and DeTrey/Dentsply.