Tomographic Assessment of reinforcement of acrylic resin denture base for palateless implant locator retained maxillary over denture.

Abstract

Objectives: This study was conducted to evaluate the effect of metallic (cobalt chromium), glass fiber and nano zirconia oxide reinforcement of acrylic resin denture base on the peri-implant crestal bone level changes in palateless locator retained maxillary over denture.Materials and Methods: Twenty-one completely edentulous male patients with maladaptive experience to maxillary dentures were selected to participate in this study. For all patients maxillary four implant-retained overdenture was constructed following the same basic principles. Every patient received four implants, two in the canine region with (3.6 mm in diameter & 12mm in length), and two in the second premolar region with (4.5 mm in diameter & 8mm in length); (Tiologic® Implants, Dentaurum, Ispringen, Germany) following the two stage surgical technique. Metal (cobalt chromium) reinforced over denture was constructed for the first group, while 5% fiber reinforced acrylic resin denture was constructed for the second group and Overdenture was reinforced using 5% of nano ZrO 2 for the group three patients. . Follow up visits were scheduled twelve and twenty four after implant loading for inspection of the prosthesis and radiographic evaluation Peri-implant crestal bone level changes were assessed using intra-oral radiographs taken with the standardized long cone paralleling technique using custom made acrylic template and the Rinn-xcp system. Results:The findings of the present study demonstrates that all the studied denture base reinforcement materials individually showed significance bone loss around implants (p< 0.05) after 12 months follow up period. Insignificant increase in the calculated means the peri-implant bone height changes of was evident during the intervals 12 -24. Group I Metal (cobalt chromium) reinforced heat cured acrylic resin denture showed more peri-implant bone loss compared to group II glass fiber and group III nano zirconia oxide reinforced acrylic resin denture base reinforcement. Although group II glass showed more peri-implant bone loss compared to group III glass during the follow up period statistically in significant difference between the two studied groups was found Conclusion: Within the limitations of this study, reinforcement of polymethyl methacrylate denture base with glass fiber or nano zirconia oxide should be considered in palateless implant retained maxillary over denture. Further clinical studies for newest reinforcement materials are necessary to ensure the effect of reinforcement within dental prostheses.