Wear Properties of Flowable Composites by Two-body Sliding Abrasion Test

Objectives: To compare the wear and surface properties of flowable composites after in vitro two-body sliding abrasion.
Methods: Flowable composites tested included 1. NovaPro Flow (Nanova Biomaterials), 2. Filtek Supreme Ultra Flowable Restorative (3M ESPE) 3. SureFil SDR Flow (Dentsply), 4. Dentex Flow (Dentex Dental Materials), and 5. G-aenial Universal Flo (GC). All flowable composites were injected into aluminum rectangular molds (5 x 20 x 1.5 mm) that were made to fit the abrasive machine. All specimens (N=45) were covered by Mylar strips and light cured by Bluephase 16i (Ivoclar Vivadent). The molds with cured composite specimens were then mounted in a sliding abrasion tester. The antagonist material used was Vita Mark II. Sliding abrasion with a length of 15 mm and a constant vertical load of 2N (wear stress ~0.2 MPa) was performed on the composites for 50,000 strokes under water flow (1L/hr).
Wear depth was measured by a digital micrometer gauge (Mitutoyo ID-F150) with an accuracy of 0.001 mm. The unmodified surface around the wear area was used as the reference for depth of the groove. Surface roughness was measured on all wear grooves and intact composite surfaces by a profilometer (Mitutoyo SJ-201). Data were analyzed via One-Way ANOVA using JMP 12.
Results: Are presented in figure 1 and 2.
Conclusions: Surface roughness increased significantly after the wear effect in all groups. There were significant differences of wear depth among the different types of flowable composites tested, but the differences may not be relevant clinically.