In-vitro wear resistance of laboratory processed composite resins

Restoring and maintaining occlusion is of primary importance in the clinical practice of dentistry. Objective: The purpose of this study was to evaluate localized and generalized wear of three laboratory processed resin systems.  Methods: Ten specimens each for localized and generalized wear of the following materials were evaluated:  1) Radica (R), 2) Gradia Indirect (G) and 3) Sinfony (S). Wear was determined using a Leinfelder-Suzuki wear simulator. A stainless steel ball bearing stylus tip was used to generate localized wear and a flattened steel stylus was used for generalized wear (400,000 cycles) with a maximum load of 80 N. A water slurry of unplasticized PMMA beads was used as the abrasive media (three-body factor) for both localized and generalized wear.  Pre and post test surface maps were uses to determine volume loss (V) in mm³ and maximum facet depth (D) in µm using a MTS 3D Profiler and AnSur 3D software. ANOVA and Tukey's test were used for statistical comparisons. Results:

Localized wear

	V	D
R	0.050 ± 0.010 a	123.6 ± 21.5 a
G	0.058 ± 0.007 a	125.2 ± 14.5 a
S	0.078 ± 0.020 b	141.2 ± 17.8 a

Generalized  wear

	V	D
R	0.347 ± 0.124 a	66.4 ± 16.7 a
G	0.348 ± 0.121 a	76.6 ± 24.4 a
S	0.824 ± 0.124 b	111.28 ± 18.7 b

Materials grouped with the same letter were not statistically different (p >0.05) For volume loss in both localized and generalized wear there was not a difference in the volume loss (V) of R and G and both were lower than S (p <0.05). Conclusion: Similar values were generated for the R and G materials for both localized and generalized wear. Both materials performed better than S in both wear challenges. Supported by Dentsply/Prosthetics.