Nahla Gamal Adly Aly <br/><br/>
Clinical evaluation of internal fit of milled BioHPP polyetheretherketone (PEEK)-based versus zirconia-based single crowns :   Randomized clinical trial /  
 التقييم الاكلينيكى للتناسب الداخلى للتيجان الفردية المصنعة من البيو اتش بى بى بولى ايثر ايثر كيتون (بييك) مقارنة بالزيركونيوم :   دراسة اكلينيكية عشوائية 
Nahla Gamal Adly Aly ; Supervised Amina Abdellatif Zaki , Lamiaa Sayd Kher Allah 
 - Cairo :   Nahla Gamal Adly Aly ,   2021 
 - 129 P. :   charts , facsimiles ;   25cm  
<br/><br/>Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics  
<br/><br/> 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 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 shade became darker after 6 months from cementation 
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<br/><br/><label>Subjects--Index Terms: </label>BioHPP polyetheretherketone (PEEK)  Single crowns Zirconia