Wear of Six Composite Resin Restorative Materials

Objective: To measure the wear of 6 restorative materials.

Methods: Eight flat disc specimens (n=8) of each composite material (d=10mm/h=4mm) were prepared using a flexible mold following manufacturers' instructions.  Each composite was placed into the mold in  2mm increments and light-cured (Elipar S10/3M ESPE/1020mW/cm²). After curing the specimens were separated from the mold, stored in distilled water (24h/37şC), mounted in brass holders (d=15mm/self-cured acrylic resin), polished (320-, 600- and 1000- grit SiC paper) and  finished (0.05µ alumina slurry + polishing cloth). The wear test was conducted on a modified UAB wear machine for 400,000 cycles using stainless steel sphere tips (d = 4.70mm, type 440C) with load of 75N. 50µ.  PMMA beads were used as the third body media (15g beads+9g water). Restorative materials were scanned before and after wear using a non-contact 3D profilometer (PROSCAN2000/Scantron/UK) to determine the loss of each restorative material (wear-depth and volume) and volume loss of enamel (ProForm software). Data were analyzed with ANOVA and Tukey/Kramer post-hoc test (p=0.05).

Results: (Mean±SD)

 Results are displayed in the table below (Mean± SD)

Material	Volume (mm3)	Depth (µm)
Gradia® Direct (GC)	0.058±0.022	125.3±12
Grandio® (Voco)	0.038±0.020	88.5±20
Herculite® Ultra (Kerr)	0.050±0.017	81.9±11
Tetric Evo Ceram® (Ivoclar)	0.053±0.014	110±14
Paradigm™ (3M ESPE)	0.034±0.023	75.6±16
TPH®3 (Caulk Dentsply)	0.044±0.02	103.3±13

 

Volume: No differences were found among the materials for wear volume (p=0.17)              

Depth: Gradia Direct had the greatest wear depth compared to other materials except Tetric Evo Ceram and TPH3 (p<0.0001). Paradigm wore less compared to Tetric Evo Ceram and TPH3 (p<0.05)  

Conclusions: Wear of composite materials is an important selection criteria for load-bearing restorations especially when placing composite resin restorations in molars. Funded in part by a grant from 3M ESPE.