A comparison of the Fitting Surface Trueness and Precision of Traditionally Constructed Complete Dentures and 3D Printed Dentures

Introduction:
Complete denture construction was revolutionised in the 1930’s when (Polymethyl Methacrylate) PMMA was developed. But it does have its drawbacks. This research compared the fitting surface trueness and precision of complete dentures against the fitting surface trueness and precision of new 3D printed dentures using additive manufacturing techniques.
Method:
10 sets of both traditional and 3-D printed dentures were constructed and assessed. Virtual digital dentures were created using scans of the master casts and try-ins from the traditional workflow. The teeth on the virtual dentures were digitally removed to produce printable denture blanks with tooth sockets. The blanks were printed. Commercially available teeth were re-inserted into the blanks. Post-print curing was completed in a light box. 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 (p≤0.05) were conducted on traditional dentures and compared against
printed baseplates without and with teeth. Means and signed standard deviations distances were calculated. Mean deviations were 0.055 +/- 0.008mm for upper traditional dentures and 0.061 +/- 0.075 mm for lowers. Printed mean deviations for upper and lower dentures measured 0.109 +/- 0.007 mm and 0.076 +/- 0.013mm. P values for upper trueness was calculated at (p= 0.000) and precision p value measured (p= 0.000). For lowers trueness p value was measured at (p= 0.006) and precision p value measured (p=0.006).
Conclusion:
Traditionally constructed dentures were significantly more accurate 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 be a factor in determining trueness and precision. Further work investigating storage of light cured dentures is needed as this may affect denture trueness and precision.