Mona Abd El-Rahman Abd El-Hafez, Mohammed Farag Ayad And Mohamed Seddik Mohamed Kamel ,

ABSTRACT
Statement Of Problem: Endo-crown Has The Advantage Of Being Minimally Invasive Preparation Achieving Maximum Tissue Conservation; However, No Data Was Available For High Performance Polymers (Bio-HPP) Endo-crowns.

Purpose: The Aim Of This Study Was To Evaluate Marginal And Internal Adaptation Of Bio-HPP Endo-crowns Fabricated By CAD/CAM And Heat Press Technique.

Materials and Methods: Thirty Freshly Extracted Human Molars Were Decoronated And Endodontically Treated. Specimens Were Prepared With Computerized Numerical Control Milling Machine (CNC) With The Following Criteria: 2 Mm Occlusal Reduction Parallel To The Occlusal Plane (butt Joint), Axial Preparation With 7-degree Total Occlusal Convergence, 3 Mm Pulpal Floordepth And Trapezoid Shape Pulp Chamber Cavity. The Pulpal Orificesand Undercuts In Mesial And Distal Canals Were Protected With Flowablecomposite Resin. Specimens Were Randomly Divided Into Two Groups According To The Processing Technique Of Bio-HPP Material; CAD/CAM And Heat Press Technique. After Cementation With Self-etch Adhesive Resin Cement, Evaluation Of The Marginal And Internal Adaptation Of Endo-crowns Were Performed Using Stereomicroscope At 40x And Cone Beam Computed Tomography. Data Were Analyzed With One-way Analysis Of Variance (ANOVA) And Independent T-test At ?=0.05.

Results: Marginal Adaptation Values Were Within The Clinical Acceptable Range, However, Heat Press Technique Showed Higher Marginal And Internal Gap Values (63.8?12.1 ?m) And (78.5?18.0 ?m) Respectively Than CAD/CAM Technique (53.7?5.5 ?m) And (58.7?7.2 ?m) Respectively (P< 0.001).Conclusion: Processing Technique Of Bio-HPP Endo-crowns Affects Marginal And Internal Adaptation To Natural Prepared Tooth.