Led Type and Composite Photoinitiator Effects on Toothbrush Wear Resistance

Abstract

Purpose: This research studied the effects of matching or mismatching dental light curing unit output color (blue or blue/vio- let, aka “multi-wave”) with the known photoinitiator content of dental restorative composites using toothbrush wear resistance. Methods: Combinations of lights and composites tested were a blue-only LED used to photocure a camphorquinone-only lay- ered composite, or a multi-wave LED used to activate composite containing Camphorquinone and Lucirin TPO photoinitiators. A ten-second exposure was provided to composite specimens utilizing all combinations of light curing units. Cured specimens were placed in a toothbrush-testing machine, simulating durations of 0, 4, 8, and 12 months of brushing. Surface profiles of composite surfaces were performed prior to as well as during tooth brushing. The average vertical loss of each specimen was measured within a 2.5-mm wide location. Regression analysis determined composite wear rates. Results: Using the blue-only LED on the Camphorquinone-containing composite resulted in a significantly lower wear rate than when using the multi-wave light on the same material. The opposite effect was found when using the blue-only LED on the Camphorquinone/TPO composite. SIGNIFICANCE: Optimal wear resistance of dental restorative composite surfaces is obtained by matching of LED spectral output with composite photoinitiator spectral needs. Funding Source: Frederick Rueggerberg