Three-body Wear of Flowable Resin Composite for Posterior Tooth Restoration

Objectives:

The aim of this study was to examine three-body wear testing of flowable resin composites for posterior tooth restoration, using a mechanical loading device in vitro.

Methods:  

The occlusal surfaces of the extracted human molars were ground to obtain the flat enamel surfaces with 120-grit silicon carbide paper under water irrigation, and then bowl shaped cavities were prepared with No.149 regular cut diamond point in center of the flat occlusal surface.  The cavities were treated with each adhesive system according to the manufacturer’s instructions, and filled with each flowable resin composite (Clearfil Majesty LV:MLV, Estelite Flow Quick:EFQ, Beautifil Flow Plus F00:BF00, and MI Fill:MIF).  The restored surfaces were finished and polished with 1500-grit silicon carbide paper.  Clearfil Majesty was used as the control.  The specimens were subjected to an in vitro three-body wear test using a mechanical loading device.  The generalized wear of the resin composite was scanned and traced at the stages of 60,000, 120,000, 180,000, and 240,000 cycles, with a profilometer (Surfcom 470A) (n=10).  The mean wear values of resin composite restorations were calculated from the tracings by using an image scanner and a computer program.  Date were statistically analyzed with one-way ANOVA and the post-hoc Tukey test.

Results:

The mean wear depths of respective materials after 240,000 cyclic loadings were as follows; MLV: 14.6±3.6µm, EFQ: 1.15±0.7µm, BF00: 5.7±3.1µm, MIF: 0.42±0.2µm and the control: 1.3±0.4µm.  The wear depths of MLV and BF00 were significantly deeper than that of the control (p<0.01), however, there were no significant differences among EFQ, MIF and the control (p>0.05).

Conclusions:

From the result of this study, two of four flowable resin composites for posterior tooth restoration showed high three-body wear resistance testing equal to the control.