Additive versus Subtractive Fabrication Techniques of Digitally Designed Complete Dentures.

Abstract

Ten patients were selected from the out-patient clinic of the Oral and Maxillofacial Prosthodontic Department, Faculty of Dentistry, Ain Shams University to compare between the accuracy and retention of the complete dentures fabricated with the CAD/CAM techniques (additive and subtractive). For each patient two complete dentures were constructed. Thus, two groups were defined according to the technique of construction of the denture. Group I: Dentures were digitally designed and milled from prepolymerized blocks of PMMA. Group II: Dentures were digitally designed and fabricated by rapid prototyping (3D printing) technique. The retention of the upper complete dentures was evaluated using digital force gauge. The accuracy the upper denture bases, lower denture bases, upper teeth, lower teeth, the fit of the upper teeth to their corresponding base and the fit of the lower teeth to their corresponding bases were evaluated using the geomagic control x software. Data was collected and statistically analyzed. The results showed that the retention of group I was significantly higher than group II. Regarding the results of accuracy of the denture bases, it was found that the least deviation was found in group I. There was a statistically significant difference between the two groups.