13 - Investigation of wear characteristics of dental composites filled with nanohydroxyapatite and mineral trioxide aggregate

Abstract

The present study evaluated the wear behavior of dental composites reinforced with nanohydroxyapatite and mineral trioxide aggregate (MTA) in artificial saliva and cold drink medium. Both the fillers were initially treated with silane. The composites were also characterized by the microhardness test. The wear test of dental composites was performed on a dental wear simulator. The parameters such as filler content, number of cycles, normal load, and speed were varied to study their effect on the wear rate of dental composites. The wear tests were performed as per steady-state condition and Taguchi experimental design. At the end, the worn surfaces were studied by the Field Emission Scanning Electron Microscope (FESEM). The finding of results indicated that the hardness of the composite was increased by 118% due to the addition of 20wt.% MTA as compared to a 100% increase due to the addition of 20wt.% nanohydroxyapatite. Further, it also indicated that for both the categories of composites in both the mediums, the wear rates were decreased with an increase in filler content, whereas it were increased with an increase in the normal load, speed, and number of cycles. However, as the filler content was increased from 10 to 20wt.%, the wear rate was increased with a high rate in case of MTA as compared to nanohydroxyapatite due to three-body abrasion by a more abraded filler.