Fracture Strength of Six-Unit Anterior Fixed Provisional Restorations Fabricated Using Various Dental CAD/CAM Systems

With the advent of implant surgery and prosthetic treatment in modern dentistry, the scope and duration of provisional restorations have gradually increased.Therefore, high fracture strength is essential for satisfactory longterm function of these restorations in patients with occlusal and temporomandibular joint problems or full-mouth rehabilitation accompanied by periodontal treatment and implant surgery.The fracture of provisional restorations is a common cause of restoration failure, resulting in patient discomfort and higher treatment costs. 1 Fractures can occur even during normal masticatory function because concentrated stresses increase with longer spans. 2 Incomplete polymerization of the resin during the hand-mixing process used to fabricate fixed provisional restorations using traditional self-curing resins results in poor surface texture, low strength, and inconsistent working conditions, all of which frequently cause prosthesis failure. 3While the heat-processing method increases the fracture strength of provisional restorations, its use is gradually decreasing due to polymerization shrinkage deformation, fine cracks, and higher manpower requirements and manufacturing times.