Eight-year randomized clinical evaluation of Class II nanohybrid resin composite restorations bonded with a one-step...

The aim of this study is to observe the durability of Class II nanohybrid resin composite restorations, placed with two different adhesive systems, in an 8-year follow-up.

Seventy-eight participants received at random at least two Class II restorations of the ormocer-based nanohybrid resin composite (Ceram X) bonded with either a one-step self-etch adhesive (Xeno III) or a control two-step etch-and-rinse adhesive (Excite). The 165 restorations were evaluated using slightly modified United States Public Health Services (USPHS) criteria at baseline and then yearly during 8 years.

One hundred and fifty-eight restorations were evaluated after 8 years. Three participants with five restorations (three Xeno III, two Excite) were registered as dropouts. Twenty-one failed restorations (13.3%) were observed during the follow-up. Twelve in the one-step self-etch adhesive group (13.5%) and nine in the two-step etch-and-rinse group (13.0%). This resulted in nonsignificant different annual failure rates of 1.69 and 1.63%, respectively. Fracture of restoration was the main reason for failure.

Good clinical performance was shown during the 8-year evaluation and no significant difference in overall clinical performance between the two adhesives. Fracture was the main reason for failure.

The one-step self-etch adhesive showed a good long-term clinical effectiveness in combination with the nanohybrid resin composite in Class II restorations.