Wettability of 3 different artificial saliva substitutes on heat-polymerized acrylic resin.

STATEMENT OF PROBLEM: The prosthodontic problems faced by a patient with xerostomia are of great concern. To aid in retention, artificial saliva substitutes should exhibit good wettability on the denture base. PURPOSE: The purpose of this in vitro study was to evaluate the wettability of 3 different artificial saliva substitutes on heat-polymerized acrylic resin and to compare these properties with natural saliva and distilled water. MATERIAL AND METHODS: A total of 150 heat-polymerized acrylic resin specimens were prepared with 25x15x2 mm dimensions. The specimens were divided into 5 groups (n=30): human saliva, distilled water, Aqwet, Mouth Kote, and Stoppers 4. The advancing and receding contact angle values were measured by using a goniometer, and the contact angle hysteresis and equilibrium angle were calculated. One-way ANOVA and the Bonferroni multiple comparisons test were performed to determine the difference between contact angle values among the groups (alpha=.05). RESULTS: The means of the 5 groups differed significantly (P<.05). The comparison between human saliva and Aqwet showed no significant difference for advancing contact angle, receding contact angle, contact angle hysteresis, or equilibrium contact angle, while comparison between the remaining groups indicated statistically significant (P<.05) results. All 3 saliva substitutes used in this study (Aqwet, Mouth Kote, and Stoppers 4) had significantly better wetting properties than distilled water. CONCLUSIONS: Human saliva had the lowest advancing, receding, and equilibrium contact angle values and the highest angle of hysteresis on heat-polymerized acrylic resin. Aqwet had better wetting ability than the other artificial salivary substitutes tested and was comparable to the human saliva on heat-polymerized acrylic resin. All saliva substitutes have better wetting properties than distilled water.