Objective: The purpose of this study was to evaluate the physical properties of rigid bite registration materials. Methods: Three bite registration materials including two commercially available bite registration materials: bisacryl-based Luxabite (LUX, DMG), vinylpolysiloxane-based Futar D (FUT, Kettenbach) and an experimental material (EXP, Kerr) were tested. Gel time and set time were tested by using a Vicat needle. Shore D hardness (n=3) was measured according to ASTM D2240. Diametral strength (n=6) was tested according to ISO 4049 standard. Volumetric shrinkage was determined using the buoyancy method. The thickness of an oxygen inhibition layer was obtained by a measuring microscope. Results: The data were analyzed by one-way ANOVA to determine the significant differences (p<0.05). EXP was a very fast curing material with a snap setting behavior. FUT was the slowest material. The bisacryl-based EXP and LUX had much higher Shore D hardness and diametral strength than the vinylpolysiloxane-based FUT. However, FUT had the lowest volumetric shrinkage. Both EXP and FUT exhibited no oxygen inhibition layer while LUX had a thick oxygen inhibition layer after set. The results were listed in the following table.
EXP | LUX | FUT | |
Gel/Set Time (sec) | 40/50 | 50/80 | 95/180 |
Shore D Hardness | 82.3 ± 0.6a* | 80 ± 0a | 28 ± 4b |
Diametral strength (MPa) | 32.8 ± 1.8a | 34.8 ± 4.2a | 5.8 ± 0.2b |
Oxygen Inhibition Layer (µm) | 0 ± 0b | 33.4 ± 3.6a | 0 ± 0b |
Volumetric Shrinkage @24 hrs (%) | 2.21 ± 0.58a | 4.11 ± 0.56b | 0.48 ± 0.17c |
*Mean with the same letter within the same row are not significantly different (p<0.05).
Conclusion: EXP and LUX are harder and more rigid bite registration materials than the elastomeric FUT. In addition, EXP sets rapidly and results in no oxygen inhibition layer thus forming a non-sticky and dry surface after set.