Minimal Invasive Rehabilitation of Tooth Loss in the Posterior Segment (MIZE-S)

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.

Inclusion Criteria:

• missing second premolar, or first molar, or second molar
• regular patient of the department of prosthodontics of the university hospital of heidelberg
• willingness to return for recall examinations on a regular basis
• written informed consent
• abutment teeth are vital or sufficiently endodontically treated
• abutment teeth are periodontally stable
• abutment teeth have only little or no defects of the hardsubstances

Exclusion Criteria:

• Pregnancy or breastfeeding
• medically compromised condition not allowing for standard dental treatment
• Patient is not able to give written informed consent
• alcohol or drug abuse
• positive bruxism and parafunctions questionaire
• Bite-Strip > 2
• Attrition Score > 3
• deep bite (Angle class II/2)
• abutment tooth height < 4mm
• missing canine or first premolar
• gap size > 18 mm
• untreated symptomatic periodontal or endodontic lesions
• abutment tooth mobility > grade I
• known allergies to materials used in this study
• poor dental hygiene
• planned change of residency