IADR Abstract Archives
Properties of A Chitosan-based Matrix to Simulate Biofilm Formation
Objectives: Biofilm adhesion on removable dentures is facilitated by an extracellular matrix containing mostly polysaccharides. This pilot study developed a cost effective and safe artificial polysaccharide matrix to simulate biofilm adhesion with the purpose to evaluate the efficiency of mechanical cleaning measures in research and education.
Methods: 48 PMMA cylinders (13mm diameter, 6mm height) were manufactured and divided into six test series with n=8 each. After sandblasting with silica-modified alumina, one frontal surface of each specimen was coated with 100µl of a 2% acetic solution containing chitosan (CS) and methylcellulose (MC) of the following concentrations: 0.0%CS and 2.0%MC (series 1), 0.1%CS and 1.9%MC (series 2), 0.2%CS and 1.8%MC (series 3), 0.5%CS and 1.5%MC (series 4), 1.0%CS and 1.0%MC (series 5), 2.0%CS and 0.0%MC (series 6). All specimens were dried for 6 hours at 45°C. The precipitated CS/MC coatings were neutralized with NaOH and rinsed. All specimens underwent abrasion tests using a tooth-brushing simulator (ELMEX sensitive brushes, load 3N, 10 cycles, 32°C, tap water). Subsequently, in each series four specimens were dyed with the disclosing agent Speikoplaque 3% (Speiko) and four specimens with Mira-2-tone Dye (Hager & Werken). The surfaces were digitally analyzed for remaining dyed coating under a light microscope.
Results: After brushing specimens in test series 1 to 3 retained no dyed material in their surfaces while in test series 4, 5 and 6 specimens retained (mean±SD) 29±12%, 58±15% and 100% dyed material. In both disclosing agents colors of the remaining CS/MC coatings were comparable to dyed biofilms in daily clinical practice.
Conclusions: Within the limits of this study it is concluded that CS/MC mixtures might be suitable to simulate a biofilm matrix on PMMA denture material concerning adhesion, abrasion resistance and dyeing. Abrasion resistance is adjustable by changing the CS/MC ratio.
Methods: 48 PMMA cylinders (13mm diameter, 6mm height) were manufactured and divided into six test series with n=8 each. After sandblasting with silica-modified alumina, one frontal surface of each specimen was coated with 100µl of a 2% acetic solution containing chitosan (CS) and methylcellulose (MC) of the following concentrations: 0.0%CS and 2.0%MC (series 1), 0.1%CS and 1.9%MC (series 2), 0.2%CS and 1.8%MC (series 3), 0.5%CS and 1.5%MC (series 4), 1.0%CS and 1.0%MC (series 5), 2.0%CS and 0.0%MC (series 6). All specimens were dried for 6 hours at 45°C. The precipitated CS/MC coatings were neutralized with NaOH and rinsed. All specimens underwent abrasion tests using a tooth-brushing simulator (ELMEX sensitive brushes, load 3N, 10 cycles, 32°C, tap water). Subsequently, in each series four specimens were dyed with the disclosing agent Speikoplaque 3% (Speiko) and four specimens with Mira-2-tone Dye (Hager & Werken). The surfaces were digitally analyzed for remaining dyed coating under a light microscope.
Results: After brushing specimens in test series 1 to 3 retained no dyed material in their surfaces while in test series 4, 5 and 6 specimens retained (mean±SD) 29±12%, 58±15% and 100% dyed material. In both disclosing agents colors of the remaining CS/MC coatings were comparable to dyed biofilms in daily clinical practice.
Conclusions: Within the limits of this study it is concluded that CS/MC mixtures might be suitable to simulate a biofilm matrix on PMMA denture material concerning adhesion, abrasion resistance and dyeing. Abrasion resistance is adjustable by changing the CS/MC ratio.
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