An Experimental Study on Improving Stain Resistance, Bacteria Resistance and Wearing Comfort of a Hawley Retainer Through a Thin Layer of Silicone Surface Coating

Abstract

Dental retainers have been used to maintain the position of the teeth as aligned after braces. Retainers are meant not only for the purpose of aesthetics but also for medical conditions that require the realigning of the teeth. Although retainers are generally meant for the benefit of braces users, retainers could result in negative consequences if not taken care of, as there could be serious infections related to this. A Hawley retainer is made of an acrylic base and stainless steel wires. Silicone has not been widely tested with dental retainers, even though it has been used in many medical cases. This experiment assessed the differences between the silicone-coated acrylic square/strip samples and the acrylic-only square/strip samples in terms of stain resistance when exposed to coffee, bacterial resistance with Streptococcus salivarius, and enhanced wearing comfort. We hypothesized that there would be less stain, less bacteria and more smoothness on the surface of a silicone coated acrylic sample than an acrylic only sample. The experimental results are somehow different from our hypothesis. The Silicone sample showed less visible stain, indicating a stronger ability to resist stains. It also had similar bacteria counts growing on the surface as the acrylic only sample. Finally, it did not perform any better in the smoothness test, indicating that it might not be more comfortable than the acrylic only sample.