Tooth Debonding of Four Denture Processing Techniques

Objectives: To examine the load bearing capability of teeth from four dentures production methods
Methods: Groups (N=8) of four denture processing methods were tested: Group 1: monolithic (Ivotion™ - Ivoclar Vivadent), Group 2: milled arch/milled base (Ivotion Dent/Ivotion Base - Ivoclar Vivadent), Group 3: conventional process (Blueline® denture teeth with Ivobase® High Impact – Ivoclar Vivadent), and Group 4: individual teeth with printed denture base (IPN® CAD teeth with Lucitone® Digital Print™ base – Dentsply Sirona). Eight full arch lower dentures were processed from each method. Teeth 21-23 were cut from each arch to be loaded. The three teeth specimens were aligned at 60 degrees from vertical in an Instron® Universal Testing Machine. A 3.8mm steel ball was loaded 1 mm from the cusp tip on tooth 22 at a loading rate of 1mm/min until failure occurred.
Results: The mean failure loads (N) were as follows: Group 1: 1117±101; Group 2: 854±140; Group 3: 633±103; and Group 4: 410±138. Using ANOVA (p≤0.05), a statistical difference was found between all groups. The failure methods also differed between each group: Group1 - within the whole specimen; Group2 - combination of within the teeth and debonding; Group3 - within the composite tooth; and Group4 - primarily debonding of the tooth from the denture base.
Conclusions: Within the bounds of this study, the load to cause failure of teeth was statistically different for all four tested denture processing methods. The failure method also differed between the groups for each tested method.