Evaluation of Marginal Bone Height Changes in implant-supported mandibular overdenture retained with Two Different Materials of Bar Attachments.

Abstract

Objective: To estimate crestal bone height changes and biting forces in three implant supported mandibular overdenture retained by Poly ether ketone (PEEK) bar and chromium cobalt (Co-Cr) bar attachment. Materials and Methods :Twenty completely edentulous patients with age range above 60 years were participated in this study. Three implants were placed in the inter foraminal area; two implants were placed bilaterally in the right and left canine areas and one near the midline. In all patients, conventional maxillary full dentures were constructed against implant-supported mandibular overdentures.A random dividing was made for all patients to be two equal groups according to the bar attachments material. Polyether ether ketone (PEEK) bar attachments were fabricated to hold the overdenture for patients in group A, while custom-designed chromium cobalt (Co-Cr) bar attachments were constructed for patients in group B. Crestal bone loss around implants was assessed by CBCT after denture pick up (T0) base line ,after 3 months(T3), 6 months(T6) and after 12 months (T12) from the pickup of the overdentures. Bite force was evaluated using a load star sensor device at base line,1 month and 3 months from overdenture pick up. Results:The obtained data revealed that bone loss in mesial, distal and average bone loss of PEEK group show higher significant value than the chrome cobalt bar group. For the buccal and lingual aspects, the difference was not statistically significant. Results of intergroup comparisons for biting force values presented that for peak and total biting force, PEEK group had significantly higher values. However, for low biting force there was no statistical significant difference between the two groups.