Comparative study of maxillary denture-base retention between CAD/CAM (3D printed) and conventional fabrication techniques: a randomized clinical study

Abstract

Background/aim Clinical studies comparing the retention values of computer-aided design/computer-aided manufacturing (CAD/CAM) denture bases with those of conventionally processed denture bases are lacking. The purpose of this clinical study was to compare the retention values of digitally 3D-printed maxillary denture bases with those of conventional heat-polymerized denture bases. Patients and methods The study was conducted on 32 completely edentulous outpatients visiting the clinic of Dental Surgery, Misr University for Science and Technology, Egypt. The patients were divided into two groups, group I received conventional complete dentures (CDs) and group II received 3D-printed CAD/CAM dentures, the retention of the maxillary denture bases was evaluated at the denture insertion and after 1, 3, 6, and 9 months. A universal testing machine was used to measure the retention of each denture. Every denture base was subjected to a slowly increasing vertical load, until the denture was totally out of place three times at 5-minute intervals. The average retention of each denture was analyzed. An independent t-test was performed for significance evaluation between both groups, while one-way analysis of variance followed by Tukey’s post-hoc test was used for multiple comparisons. Results Group II showed a significant increase (P<0.05) in retention in all of the follow-up periods (at the time of denture insertion and after 1, 3, 6, and 9 months) when compared with group I. Definite time intervals of both groups showed a significant difference (P<0.05) in retentive values in all follow-up periods, except for the last two follow-up periods from denture insertion – 6 months and from denture insertion – 9 months showed the insignificant difference in both groups. Conclusion The retention of the maxillary CD prepared with the 3D print CAD/CAM method was significantly higher than conventional heat-polymerized denture bases, meaning that the 3D print CAD/CAM method can meet the clinically acceptable precision for the design and construction of CDs with higher retentive means of completely edentulous patients.