COMPARISON OF PERI-IMPLANT CLINICAL INFLAMMATORY PARAMETERS AMONG SCREW RETAINED CAD/CAM METAL BAR AND ZIRCONIA BAR FOR PATIENTS WITH RECONSTRUCTED MANDIBLES

Background: Segmental resection of the mandible results in severe disturbance of chewing function. Advances in microvascular surgeries and CAD/CAM technology helped with the prosthetic rehabilitation of reconstructed mandibles.
Purpose: The aim of this study was to assess metal bar versus zirconia bar in patients with reconstructed mandibles that were rehabilitated with implant retained mandibular removable partial overdenture concerning the peri implant gingival index and probing depth.
Materials and methods: fourteen patients were selected according to the inclusion criteria, the participants were stratified equally into two groups, patients were assigned to receive either metal bar or zirconium bar. Preparation of implant sites started with pilot drill followed by sequential drilling under copious refrigerated irrigation. Monthly follow up appointments were scheduled for each patient. After second stage surgery, abutments were secured to implant fixtures. Open top impression technique was used for bar fabrication using CAD/CAM technology. The bar was screwed in the patient’s mouth and checked for passive fit. Construction of the implant assisted removable partial overdenture took place in the conventional way. Female part were picked up directly in the patient’s mouth. Patients were recalled one week, 3,9 and 12 months after delivery for assessment of gingival index and probing depth.
Results: Mann-Whitney U test was used to analyze the gingival index score between the two groups metal bar and zirconium bar. The metal bar group mean and standard deviation was 0.40±0.48 after 1 week and 0.36±0.32 after 3 months, 0.30±0.42 after 9 months, 0.20±0.42 after 12 months. While for zirconium group 0.30 ± 0.70, 0.28± 0.42 ,0.25±0.32, 0.10±0.32 respectively after 1 week,3 months ,9 months and 12 months. There was a statistical significance between the groups in 9 and 12 months, where P value was Conclusion: Within the limitation of this study, zirconia metal bar is considered more biocompatible than the metal bar.