Clinical long-term survival of two-retainer and single-retainer all-ceramic resin-bonded fixed partial dentures

All-ceramic resin-bonded fixed partial dentures (RBFPDs) were introduced as a conservative treatment approach 15 years ago. The purpose of this prospective study was to evaluate the long-term clinical survival of RBFPDs made with a conventional two-retainer design or a cantilever single-retainer design.

A total of 37 anterior RBFPDs were made from the glass-infiltrated alumina ceramic In-Ceram. Sixteen RBFPDs with a conventional two-retainer design were inserted in 14 patients, and 21 RBFPDs with a cantilever single-retainer design were inserted in 16 patients. Panavia or Panavia 21 were used as luting agents either after silica-coating and silanation or after air-abrasion only. Patients were recalled every year for a clinical examination to evaluate the restorations with regard to function and possible failures. The mean observation time in the two-retainer group was 75.8 months, and in the single-retainer group it was 51.7 months.

No restoration debonded. In the two-retainer group, one restoration was lost because it fractured after 3 months at both connectors and one restoration was removed alio loco accidentally. Also in this group, four RBFPDs fractured within 15 months after insertion at one connector, but the pontic remained in situ as a cantilever RBFPD for several years. In the single-retainer group, only one FPD fractured and was lost 48 months after insertion. The 5-year survival rate was 73.9% in the two-retainer group and 92.3% in the single-retainer group. When unilateral fracture of a FPD was taken as criterion for failure, the five-year survival rate decreased to 67.3% in the two-retainer group.

Cantilever all-ceramic resin-bonded fixed partial dentures made from high-strength oxide ceramics present a promising treatment alternative to two-retainer RBFPDs in the anterior region.