Wear of posterior restorative materials is a significant clinical problem over the life of the restoration.� Objectives: To measure and compare the in vitro wear of three glass ionomer restorative materials (Riva Self-Cure LV/SDI, ChemFil Rock/Dentsply, Fuji IX/GC) and (control) a resin composite (Z100/3M ESPE) restorative material.
Methods: Eight flat disc specimens (n=8) of each material (d=10mm/h=4mm) were prepared using a flexible mold following each manufacturers' instructions. The capsules of glass ionomer materials were mixed in an amalgamator OptiMix (Kerr) for 8 seconds at 4,000rpm. ChemFil Rock was mixed for 12 seconds and placed in the flexible mold �covered with a glass slide and allow to set. The composite resin was placed in 2mm increments in the same mold and light-cured with an Elipar S10 curing light (3M ESPE/1020mW/cm2). Specimens were stored in distilled water (24h/37�C), mounted in brass holders (d=15mm/self-cured acrylic resin), polished with a series of abrasive disc (320-, 600- and 2000- grit SiC paper) and finished (0.05� alumina slurry+polishing cloth). �The wear test was conducted on a modified UAB wear machine with a 2mm slide for 300,000 cycles using stainless steel tips (d=4.70mm) with load of 50N at 50cycles/min. 50� 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 loss of restorative material (wear-depth and volume) by superimposing the two images (ProForm software). Data were analyzed with ANOVA and Tukey/Kramer post-hoc test (p=0.05).
Results: (Mean�SD)
Material | Volume (mm3) | Depth (�m) |
Riva Self-Cure LV/SDI | 0.4�0.1 | 52.8�13 |
ChemFil Rock/Dentsply | 0.3�0.06 | 40.3�11 |
Fuji IX/GC | 0.2�0.08 | 24.5�12 |
Z100/3M ESPE | 0.02�0.002 | 7�3 |
Conclusions: Z100 produced significantly less wear than any of the glass ionomer materials tested (p<.0001). �Fuji IX had significantly less wear than Riva self-cure LV (p<0.05). No other differences were found. �
Keywords: Glass ionomers and Wear