Clinical Performance of Two Different Designs of All-ceramic Resin-bonded Fixed Dental Prostheses in the Posterior Segment - a Randomized Controlled Pilot Study.

Tooth loss can be addressed by different rehabilitative strategies. Implant-supported crowns and conventional bridges (fixed dental prostheses [FDPs]) are well established treatment alternatives. Implant therapy is sometimes impossible, however, because of patient-related risk factors or economic issues. In such cases therapy with an FDP requires extensive removal of tooth structure to provide enough space for the restoration and to ensure mechanical retention if the abutment teeth are sound. Alternatives for rehabilitation requiring minor or no preparation of the anchoring teeth are desirable. Resin-bonded bridges meet this demand for minimal invasiveness and have been used clinically successfully. Sometimes, however, patients choose a conventional FDP over a resin-bonded one (RBFDP) for esthetic reasons since the adhesive wings, which are traditionally made of a cobalt-chromium alloy, might be exposed while speaking or smiling or account for a colour change of the abutment teeth. Such patients profit from an all-ceramic RBFDP. Today, the clinical performance of different all-ceramic RBFDP designs has not yet been evaluated under randomized controlled conditions. The aim of this pilot study is to calculate the sample size that allows us to accept the hypothesis that the two designs tested are similar regarding their clinical performance with adequate statistical power.