Biting Force and Chewing Efficiency of Conventional and CAD/CAM Complete Dentures: A Cross-over Study

Participant selection and treatment This study will include a clinical experiment with a cross-over clinical trial design. For this study, 27completely edentulous participants with age range of 50-65 were selected from the outpatient clinic of the Removable Prosthodontic Department, Faculty of dentistry, Kafr Elsheikh University, Egypt. All participants had Angle class I jaw relation maxillomandibular relationship, normal alveolar ridge volume, no temporomandibular joint disorders, no heart disease, and no systemic diseases that affect the complete denture treatment procedures.

To reduce the effect of order of treatment on MBF, were successively given the following prosthesis i) complete dentures fabricated by the conventional technique ii) 3D printed complete dentures iii) milled complete dentures in a random order.

Construction of the CADCAM 3D printed denture The same steps of the conventional technique will be performed till the adjustment of occlusion rims then in the dental laboratory, the maxillary and mandibular definitive casts and the occlusal rims will be prepared for scanning with scan spray. Scanning will be performed with an optical 3D scanner . The files from the laser-scan will be translated into stereolithography (STL) files and the CDs are virtually designed in ExoCad software. After minor modifications in the positions of teeth were made, fabrication of the dentures will be approved and the digital denture base will be fabricated using 3D printing technique from Dental Pink resin

Construction of the CAD/CAM milled denture Once the complete denture has been virtually designed in CAD software (ExoCad software) a preview will be sent for evaluation using 3D viewing software. After minor modifications in the positions of teeth were made, fabrication of the dentures will be approved. The digital denture will be fabricated by the command software of the milling machine (ExoCad 5x milling machine) from prepolymerized resin acrylic pucks and the teeth (TSM Acetal Dental) were milled into template .After that the denture will be finished and polished according to the traditional procedures For all groups, after placement, clinical evaluations of the fit, retention, stability, occlusal relationship, esthetics, and phonetics were performed. Assessment of the occlusion was made with articulating paper, chairside adjustments were made and premature contacts were corrected. The patient was given a proper program for denture insertion and oral hygiene measures.

Assessment of biting force