Evaluation of Marginal fit of 3 units fixed partial dentures fabricated with polyether ether ketone and Zirconia

Abstract

Introduction: Increasing society's demand for more beautiful teeth on the one hand and the inherent problems of metal-ceramic crowns such as the appearance of a black metal collar and the change in the color of the gum caused by metal corrosion on the other hand has led to the all ceramic restorations have a great deal of popularity between patients in dentistry. Among the many indicators in the success of a restoration the marginal fitness is important, hence the purpose of this study is to help to select a restoration that has better marginal fitness. Materials and Methods: Two acrylic models of the first molar and first premolar were prepared with a shoulder finish line in a conventional manner of full-ceram preparation and we made an impression and duplicated to a resin dye casting process was performed and metal dies were made without any irregularities and four points was determined on the dye to evaluate the marginal integrity and was made impression 26 times from the dye and molds were poured with type ΙV stone. The casts were divided into two groups: 1. For making Zirconia FPD 2. For making of BioHPP FPD. 3 units Fixed partial dentures are made by the CAD / CAM system. Then, marginal adaptation of the crowns on the original metal dye was evaluated by a Stereo Microscope; a digital camera and a computer. The results of the study were reported using descriptive statistics (mean ± standard deviation and frequency (%)). Independent t-test was used for comparing marginal adaptation in two groups. Normality of data was analyzed using Kolmogorov-Smirnov test. Statistical analysis was performed using SPSS17 software and a significant level of p <0.05 was considered. Results: According to the results of this study, mean of marginal gap in zirconia crowns were 65.85 ± 44.2 μm and in the BioHPP crowns was 66.98 ± 47.4 μm. The results of the T-test indicated that zirconia crowns have a slightly better marginal integrity. Conclusion: The rate of marginal discrepancy in zirconia and BioHPP crowns is below 100 μm and is clinically acceptable.