CLINICAL EVALUATION OF TREE-UNIT FPD WITH ENDOCROWN PREPARATION OF THE DISTAL ABUTMENT TOOTH

Abstract

Introduction: The endocrown is a mean for restoring endodontically treated teeth. It has a circumferential preparation with a butt-joint border and accessory retention within the pulp chamber. It does not require root preparation for placement of posts or post and cores making it a more conservative restoration that evades the shortcomings of the above-mentioned. Aim: Evaluation of the clinical performance and longevity of three- unit FPD's with endocrown preparation for the distal abutment tooth and comparison with a conventional FPD'semploying the Split-mouth method. Methods and materials: Patients with identical defects on the maxillary or mandibular dental arches are examined. 22 patients are chosen amongst them with a minimal step of randomization (n=3). The design of the study is based on the method of auto-control and consistent with the CONSORT Statement. The type of the preparation design for the distal abutment tooth is randomly chosen for each side of the dentition. Both FPD's are fabricated from Laboratory resin composite (Vita LC/VM) with infrastructure made from glass fibres - Turka GS/CSB (Stick Tech). Silane agent is applied to the inner aspects of the bridges and a 3 Steps adhesive system is used (Optibond (Kerr / Hawe). Luting is carried out with Resin cement (RelyX Ultimate Adhesive Resin Cement (3M ESPE)). In order to assess the clinical performance of the FPD's a modified USPHS criteria was used. All patients were examined at predetermined time periods by one of the researchers. Analyses of the results are performed with descriptive statistics and Kaplan-Meier longevity test. Results: The evaluation period is 4 years for all FPD's. Regular control appointments were conducted at 6 months, 1, 2, 3 and 4 years post cementation. The modified USPHS criteria showed full Alfa scores on colour match and anatomic contour. Kaplan Meier survival analysis showed 93.22% survival rate for all FPD's - conventional and endocrown retained. No statistical difference was observed between the different types of distal abutment preparation designs as well as between genders with an exception for the variable ``Chipping{''} (p=0.018). The success rates were generally lower than the survival rates at 71.45%. Conclusion: Within the limitations of this study it is concluded that both classic and endocrown retained FPD's made from laboratory composite resin, reinforced with FRChave a satisfactory performance for the 4 year evaluation period.