Evaluation of Clinical Performance of 3D Printed Polyether Ether Ketone (PEEK) Inlays Compared With Milled Indirect PEEK Inlays Versus Indirect Resin Composite Inlays Over One Year Period of Time (A Randomized Clinical Trial)

The study will be conducted in Conservative Dentistry Department, Faculty of Dentistry, Cairo University; The operator in charge will be Donia Mamdouh Elshafey Patients will be selected from the outpatient clinic of the department Conservative Dentistry Department, Faculty of Dentistry, Cairo University All cavity preparations will be performed with fine inlay burs according to inlay cavity principles. The walls facing each other will be prepared 5 to 6 degree divergent with 80 μm diamond burs and were finished with 25 μm diamond burs. All internal angles will be rounded and all edges will terminate in the enamel. The pulpal floor will be prepared at a depth of at least 1.5 mm. The teeth will be discarded if isthmus width was more than 2/3 of the distance between the tubercule tips, or if the walls are thinner than 2 mm before the preparation or thinner than 1.5 mm after the preparation. The caries affected dentin tissue at the cavity floor will be left. The teeth will be discarded from study if the pulp is exposed. To eliminate irregular areas in the cavities, a liner will be applied as a blockout material. Then the operator will adhere strictly to the manufacturer's instructions in the imaging, computer design and machining of the restorations either 3D printing or milling procedure.

The prepared teeth for the indirect restorations will be scanned with an optical 3D camera (CEREC Omnicam, Dentsply Sirona, Bensheim, Germany), inlays will be designed by a CAD software (CEREC SW 4.6.1, Dentsply Sirona), and files will be created in STL format (inLab CAD SW 18.1, Dentsply Sirona) then inlays will additively manufactured After the printing process is finished, the inlays will be immediately removed from the building platform and cooled down at room temperature. The inlay will be adapted individually to its cavity, and the occlusal surface will be recontoured. Such post processing also will be performed on the milled inlays. After all inlays are adequately adapted, they will be adhesively inserted into the cavities.