CAD/CAM produces dentures with improved fit.
OBJECTIVES
Resin polymerisation shrinkage reduces the congruence of the denture base with denture-bearing tissues and thereby decreases the retention of conventionally fabricated dentures. CAD/CAM denture manufacturing is a subtractive process, and polymerisation shrinkage is not an issue anymore. Therefore, CAD/CAM dentures are assumed to show a higher denture base congruence than conventionally fabricated dentures. It has been the aim of this study to test this hypothesis.


MATERIALS AND METHODS
CAD/CAM dentures provided by four different manufacturers (AvaDent, Merz Dental, Whole You, Wieland/Ivoclar) were generated from ten different master casts. Ten conventional dentures (pack and press, long-term heat polymerisation) made from the same master casts served as control group. The master casts and all denture bases were scanned and matched digitally. The absolute incongruences were measured using a 2-mm mesh.


RESULTS
Conventionally fabricated dentures showed a mean deviation of 0.105 mm, SD = 0.019 from the master cast. All CAD/CAM dentures showed lower mean incongruences. From all CAD/CAM dentures, AvaDent Digital Dentures showed the highest congruence with the master cast surface with a mean deviation of 0.058 mm, SD = 0.005. Wieland Digital Dentures showed a mean deviation of 0.068 mm, SD = 0.005, Whole You Nexteeth prostheses showed a mean deviation of 0.074 mm, SD = 0.011 and Baltic Denture System prostheses showed a mean deviation of 0.086 mm, SD = 0.012.


CONCLUSIONS
CAD/CAM produces dentures with better fit than conventional dentures.


CLINICAL RELEVANCE
The present study explains the clinically observed enhanced retention and lower traumatic ulcer-frequency in CAD/CAM dentures.
['Steinmassl|Otto|O|', 'Dumfahrt|Herbert|H|', 'Grunert|Ingrid|I|', 'Steinmassl|Patricia-Anca|PA|http://orcid.org/0000-0002-6996-8242']
D017076:Computer-Aided Design D003764:Dental Materials D003819:Denture Bases D003779:Denture Design D003781:Denture Retention D066298:In Vitro Techniques D013499:Surface Properties
CAD/CAM dentures Denture base congruence Complete dentures Dental materials Denture fit PMMA resin