54 - Evaluating Mechanical Properties of Prismo and Traditional Stainless-Steel Crowns

Abstract:

Objective: Prismo crowns are a new brand of stainless-steel crowns available in multiple colors. Limited information exists regarding the mechanical properties of these crowns. The aim of this study was to evaluate the mechanical properties of Prismo crowns in comparison to brands currently on the market (3M and NuSmile). Three tests were included in this study: wear testing, hardness testing, and toothbrush abrasion.

Methods: Wear testing was performed using an Alabama wear simulator with flat-ended stainless-steel cylindrical styli as antagonists for a fixed number of cycles. Software was used to evaluate differences between before and after digital models of the crowns. Hardness testing was performed on flat samples of each material specimen using Vickers hardness testing. Toothbrush abrasion was performed to evaluate the color stability of the Prismo Crowns using a toothbrush simulation machine for a fixed number of cycles equivalent to 8 years of expected brushing. Change in color was evaluated using a spectrophotometer and photographs.

Results: Prismo crowns showed significantly less volume loss due to wear compared to 3M and NuSmile brands. There was not a significant difference between 3M and NuSmile. There was a significant difference in microhardness between all 3 brands, with Prismo > 3M > NuSmile. There was a significant difference in the color of Prismo crowns before and after toothbrush cycling.

Conclusions: Prismo crowns have higher microhardness and are less susceptible to wear deformation. The color of Prismo crowns is not stable and begins to fade after 2 years or less of expected brushing habits.

Identify Supporting Agency and Grant Number: Research supported by Indiana University School of Dentistry Graduate Research Committee