Studies on the effects of abrasives on acrylic resins

Abstract

Cleanliness of the artificial denture is imperative in order to eliminate mouth odors, minimize tissue irritation, and maintain good oral tissue tone. Many types of materials are now employed for cleaning dentures. The effect of various denture cleansers commonly used on acrylic resins was studied by means of weight and surface loss measurements, luster changes, and microscopic examinations of the surface. A mechanical brushing machine was employed and a technique was developed for using rotating specimens. Preliminary to this study, a survey of denture patients was made at Indiana University School of Dentistry. The materials selected for this study and the brushing period employed were based on the results of this survey. The brushing period of 20,000 strokes was believed to be comparable to two years of normal brushing. 1. Immersion in proprietary compounds and in household bleaches has no effect on the resin, either by change in weight or color. 2. Brushing with household cleansers produced marked weight loss and the results obtained on the rotated specimens were approximately the same as those produced when the specimens were allowed to remain stationary. 3. The weight loss produced by the most abrasive dentifrice was less than one-half that caused by the household cleansers while only one proprietary compound induced any appreciable weight change. Miscellaneous agents such as salt, soda and soap had little or no effect. 4. A deep grooving action was produced by the more abrasive materials when the specimen remained stationary. With the rotated samples no deep scratches resulted. However, weight and surface loss measurements indicated a substantial amount of resin was being removed. 5. Surface loss with household cleansers reached a maximum of one-third millimeter. 6. Luster changes on rotated specimens correlated closely with data obtained in the other tests. It is apparent from this study that household cleansers, and possibly some abraisive dentifrices, are contraindicated for routine use in cleaning artificial dentures. Prolonged use of such materials may affect the fit of the denture and make maintenance of a clean surface more difficult.