Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics

Aim: to evaluate the internal fit of milled BioHPP PEEK- copings veneered with Visio.lign composite resin in comparison with zirconia coping veneered by e-max as single posterior crowns. Methodology: 20 full coverage posterior crowns were fabricated for endodontically treated molars divided into 2 groups according to the material used. Ten milled BioHPP PEEK-based crowns (Group 1) and Ten zirconia crowns (Group 2). The preparations were standardized with an equigingival, deep chamfer finish line for all teeth. BioHPP PEEK and zirconia copings were fabricated by CAD/CAM technology. These coping were veneered according to manufactures instructions either by special composite resin or low fusing glass ceramic respectively.The internal fit of crowns were recorded using a replica technique with light body silicone material stabilized with a regular set putty. Each replica was sectioned buccolingually and mesiodistally and then evaluated at five pre-determined sites using a stereomicroscope at 30{u00D7} magnification.The restorations were cemented then clinical evaluation of these crowns was assessed regarding patient satisfaction and secondary caries every two months for one year. Results: The mean marginal gap values of PEEK crowns showed non significant higher marginal gap than Zirconia crowns (P-value = 0.260, Effect size = 0.507). Results revealed high patient satisfaction in patients received Zirconia veneered crowns, while there was statistically non significante decrease in patient satisfaction after 6 months in patients who received PEEK crowns. As 3 patients from the PEEK crowns group noticed that the crowns{u2019} shade became darker after 6 months from cementation

Issued also as CD