Effect of denture cleansers on metal ion release and surface roughness of denture base materials

Abstract

Chemical disinfectants are usually associated with mechanical methods to remove stains and reduce biofilm formation. This study evaluated the effect of disinfectants on release of metal ions and surface roughness of commercially pure titanium, metal alloys, and heat-polymerized acrylic resin, simulating 180 immersion trials. Disk-shaped specimens were fabricated with commercially pure titanium (Tritan), nickel-chromium-molybdenum-titanium (Vi-Star), nickel-chromium (Fit Cast-SB Plus), and nickel-chromiumberyllium (Fit Cast-V) alloys. Each cast disk was invested in the flasks, incorporating the metal disk to the heat-polymerized acrylic resin. The specimens (n=5) were immersed in these solutions: sodium hypochlorite 0.05%, Periogard, Cepacol, Corega Tabs, Medical Interporous, and Polident. Deionized water was used as a control. The quantitative analysis of metal ion release was performed using inductively coupled plasma mass spectrometry (ELAN DRC II). A surface analyzer (Surftest SJ-201P) was used to measure the surface roughness (µm). Data were recorded before and after the immersions and evaluated by two-way ANOVA and Tukey's test (α=0.05). The nickel release proved most significant with the Vi-Star and Fit Cast-V alloys after immersion in Medical Interporous. There was a significant difference in surface roughness of the resin (p=0.011) after immersion. Cepacol caused significantly higher resin roughness. The immersion products had no influence on metal roughness (p=0.388). It could be concluded that the tested alloys can be considered safe for removable denture fabrication, but disinfectant solutions as Cepacol and Medical Interporous tablet for daily denture immersion should be used with caution because it caused greater resin surface roughness and greater ion release, respectively.

Effect of cleanser solutions on the color of acrylic resins associated with titanium and nickel-chromium alloys

“…Paranhos et al 14 performed 20-minute immersions in sodium hypochlorite (0.5% and 1%) for 180 days and found no color changes for resins; however, in the same period with immersions of 8 hours, a 1% solution caused "slight" changes in NBS units. 26 Similarly, Hong et al 16 found changes with 8-hour immersions in a 0.5% solution, indicating a trend of increasing ΔΕ values with time. Therefore, the use of sodium hypochlorite as an everyday cleanser would require a study using lower concentrations over longer periods.…”

“…7,17 In relation to the metallic components, weight loss and ion release, 19 as well as tarnishing and spot corrosion, 25 were observed in Co-Cr alloys after immersion in a citric acid product (Medical Interporous). With regard to titanium, Davi et al 26 did not find alterations in surface roughness, but the color was not evaluated. Although mouthwashes can have adverse effects on resins (that is, stains on denture bases and teeth), 2 the results are not different from those of the other solutions.…”

“…6,24 Water was used as a control because it is indicated for overnight immersion, 5 and it prevents the release of ions. 25,26 Among the properties of the acrylic resin, color stability is considered to be the most decisive in both the longevity of the prosthesis and in patient satisfaction. 16 The measurements were performed with a colorimeter using an objective, and quantitative readings were analyzed and correlated to NBS units for comparing the color and quality control functions.…”

“…There is controversy about tablets, specifically regarding whether they cause damage to the resin and the metallic components of the prosthetic device. The water temperature, 27 immersion time 26 and the composition of the product 8 are critical factors. Studies have found that for acrylic resins, Corega Tabs have a greater whitening effect than Polident, 17 Bony Plus 18 and a 0.5% hypochlorite solution.…”

The effect of different chemical intra-oral prostheses cleansers on the surface properties of Parylene-coated PMMA

“…The roughening effect of cleansers was significantly evident with Steradent which produced the roughest uncoated PMMA surface. The increase in surface roughness caused by denture cleansers has been reported in the literature before, especially regarding alkaline peroxide-based solutions 26,28,37) . When the alkaline peroxide reacts with water it produces a solution of hydrogen peroxide and nascent oxygen.…”