Surface morphology of silicone soft relining material after mechanical and chemical cleaning.

PURPOSE: The objective was to investigate the influence of chemical and mechanical cleaning on the surface morphology of a silicone soft relining material. METHODS: Three plate-shaped specimens were prepared for each group (Control, Hard and Soft) by laminating a 1.5-mm-thick silicone soft relining material. The Control group specimens were stored in water, and the Hard and Soft group specimens were cleaned with hard and soft bristle denture brushes, respectively. Abrasion testing with a toothbrush and immersion testing with an enzyme-containing peroxide denture cleanser were performed, simulating a period of approximately 4 months. The arithmetic mean roughness (Sa) and maximum height of the cross-section (Sz) were measured before and after abrasion and immersion testing. RESULTS: Sa was 4.9±0.9, 22.1±4.2 and 44.2±4.0µm in the Control, Soft and Hard groups, respectively. Sz was 257.5±31.7, 392.0±23.8 and 452.2±41.9µm in the Control, Soft and Hard groups, respectively. After abrasion testing, Sa and Sz differed significantly between the Soft and Control groups and between the Hard and Control groups. Sa was 2.2±1.2µm before and after immersion, and Sz was 142.1±81.4µm before and after immersion. No significant difference was noted in either Sa or Sz in the Control specimens before or after immersion. CONCLUSIONS: Surfaces cleaned using a soft bristle brush were less likely to roughen than those cleaned with a hard bristle brush under the conditions of this study. Additionally, chemical cleaning using the enzyme+neutral peroxide denture cleanser did not roughen the surface of the silicone soft relining material.

Inhibition of denture plaque by TiO2 coating on denture base resins in the mouth.

STATEMENT OF PROBLEM: Information is lacking about antiadhesion effect of titanium dioxide (TiO2) coating on denture base resins in the mouth. PURPOSE: The purpose of this clinical study was to investigate the antiadhesion effect of TiO2 coating on denture base resins. MATERIAL AND METHODS: Ten healthy dentate participants (mean 27 ±2 years of age) participated in this study. Disks and palatal appliances were made with denture base resin. They were divided into 2 groups: a TiO2-coated group and an uncoated group. A primer and a top coat containing TiO2 were applied to the surfaces of the resin by means of an air spray. In the denture plaque staining test, resin disks were fixed to the retainer, placed in each participant's mouth for 3 days, and stained with a dental plaque-disclosing solution. The staining rate was calculated. The resin disks and palatal appliances were used to measure the total number of microbes. The resin specimens were placed in each participant's mouth for either 3 or 7 days and swabbed to count the total number of microbes. The chewing gum adherence test was performed both subjectively and objectively. Subjectively, each participant wearing a palatal appliance rated adherence using a visual analog scale. The objective test was performed with a chewing gum adhesion test. The staining rate, the total number of microbes, and the visual analog scale values were statistically analyzed using the Wilcoxon signed rank test, and the adhesive force was statistically analyzed using a Student t test. RESULTS: In the denture plaque staining test, the measurement of microbes, and the resin chewing gum adherence test results, significant differences were observed between the TiO2-coated groups and the uncoated groups. CONCLUSIONS: TiO2 coating of the denture base acrylic resin inhibited the adhesion of microbes, denture plaque, and highly adhesive food.