Investigating Trueness and Precision of 3D Printed Denture Fitting Surfaces
Objectives: Complete denture construction was revolutionised in the 1930’s when PMMA (Polymethyl Methacrylate) was invented. It does have its drawbacks. This research compared the fitting surface trueness and precision of traditional complete dentures against the fitting surface trueness and precision of 3D printed dentures using additive manufacturing techniques.
Methods: 10 sets of traditional and 3D printed dentures were constructed and assessed. Denture CAD files were created using scans of the master casts and try-ins from the traditional workflow. The teeth on the digital dentures were removed to produce printable denture baseplates with tooth sockets. Commercially available teeth were re-inserted into the printed baseplates. Post-print processing was completed to manufacturers' instructions. Scans of traditional and printed dentures were taken at each stage of production and measured for trueness and precision against the model scans.
Results: Paired T tests were conducted on traditional dentures and compared against printed baseplates without and with teeth. Means and signed Standard Deviation (p≤0.05) distances were calculated. Means for upper traditional dentures was 0.055mm, lowers measured 0.061mm. Means for printed upper and lower dentures measured 0.109mm and 0.076mm. Traditional upper and lower precision was 0.081mm and 0.085mm. Printed upper and lower precision was measured at 0.143mm and 0.108mm.
Conclusions: Traditionally constructed dentures were more true and precise than printed dentures. The results for printing were promising. When printed, lowers were more accurate than traditionally constructed dentures until teeth were added. Light curing and storage of baseplates prior to adding teeth may affect dimensional trueness and precision. Further work investigating printing and storage of light cured dentures is needed as this may affect denture trueness and precision.