Direct, Inlay-retained, Fiber-reinforced-composite Restorations with Two Pontics: 5-year Clinical Follow-up

Objectives: This study evaluated the clinical performance of direct, inlay-retained, fiber-reinforced-composite restorations (DIFRCR) with two pontics up to 5.5 years. Methods: Between June-2002 and December-2007, 20 patients (15 females, 5 males, 23-82 years old) received a total number of 25 posterior DIFRCRs (n=20 mandible, n=5 maxilla) at the Dental School, Groningen, The Netherlands. When one molar was missing, two premolars were built-up in order to minimize the occlusal table. All restorations were made under rubber-dam, directly, using a three-step adhesive system (Quadrant Unibond Primer and Sealer, Cavex), with unidirectional, preimpregnated E-glass fibers (everStick C&B, StickTech) in combination with mainly one resin composite (Clearfil Photo Posterior, Kuraray). In 12 cases, colour was improved using a flowable composite (Sinfony, 3M ESPE) during build-up. After baseline recordings, patients were followed at 6 months and annual recalls. Patients were instructed to call upon experience of a failure. The evaluation protocol involved technical failures such as chipping or fracture (tooth/restoration). Also information related to the reason for this therapy option was obtained through a questionnaire. Results: This restoration type was chosen primarily due to financial reasons (50%), fear from implant operations (30%) and not wanting preparations on the abutment teeth through extensive drilling (20%). One chipping was observed on the occlusal surface in one restoration at 1-year recall. After rubber-dam removal, during occlusal adjustment, in 6 cases, fiber was exposed at small spots on the occlusal and buccal surfaces. They were all repaired using CoJet system (3M ESPE) in the same session and remained functional. Life-tables calculated from the data and estimated survival rate after 5 years was 97.6% (Kaplan-Meier, 95% CI). Conclusions: Direct, inlay-retained, fiber-reinforced-composite restorations offer acceptable clinical survival rate with the adhesive system and the veneering composite used.