Examination of 2-methacryloyloxyethyl phosphorylcholine polymer coated acrylic resin denture base material: surface characteristics and Candida albicans adhesion.

The aim of this study is to evaluate the effects of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer coating with various concentrations onto acrylic resin denture base material on surface characteristics such as contact angle and surface roughness and on Candida albicans adhesion which is the major factor of denture stomatitis. Specimens, prepared from heat-polymerized acrylic denture base material, were divided into control and three test groups, randomly. Surfaces of the specimens in test groups were coated with poly(MPC) (PMPC) by graft polymerization of MPC in different concentrations (0.25 mol/L; 0.50 mol/L and 0.75 mol/L), while no surface treatment was applied to the control group. Contact angles and surface roughness were examined, and chemical composition of the surfaces was analyzed by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (FTIR) to verify the presence of PMPC coatings. Then, specimens were incubated with C. albicans for 18 h and the number of adhered cells was determined. Upon PMPC coating, the contact angle values statistically decreased, but no difference was found in surface roughness values. A statistically significant decrease was observed in C. albicans adhesion in parallel with the increase in the MPC polymer concentration. There was no significant difference between 0.50 mol/L and 0.75 mol/L groups in terms of adhesion. These findings indicated that graft polymerization of MPC on acrylic denture base material reduces the adhesion of C. albicans, and may be evaluated as a coating for prevention of denture stomatitis.

Effectiveness of different cleaning agents against the colonization of Candida spp and the in vitro detection of the adherence of these yeast cells to denture acrylic surfaces.

PURPOSE: The aim of this study is to examine the effect Klorhex and Fittydent, which are used as cleaning agents on the adhesion of Candida on the surfaces of acrylic denture and palatal mucosa. In addition, ability of yeasts to adhere to acrylic strips was evaluated after applying these agents in vitro. MATERIALS AND METHODS: Each group of 15 patients cleaned their dentures with either Klorhex or with Fittydent. The control group cleaned their dentures with water. RESULTS: It was found that 62.2% of the patients had colonies of Candida species on their palatal mucosa which was reduced to 51.1% after using these cleaning agents. The colonization rate with Candida spp on their dentures was reduces from 82.2% to 68.8% using these cleaning agents. The mean adhesion value of the Candida strains isolated from the acrylic strips were found to be 75 cell/strip prior to applying the Klorhex and Fittydent and 37.5 cell/strip and 15 cell/strip after applying these agents, respectively. CONCLUSION: These results showed that Klorhex and Fittydent have a certain preventive effect on the colonization rate of Candida spp on the surface of these dentures, the palatal mucosa, as well as on the acrylic strips in vitro.

Effects of short-term adaptation to new complete dentures on perception thresholds for interocclusal thickness in experienced and non-experienced denture wearers.

BACKGROUND: The ability of patients to discriminate thickness can change with time after the insertion of new complete dentures, and this adaptation may differ according to the experiences of the patients. If so, an education program to reinforce the oral functions may be needed. This study was to evaluate patients' ability to discriminate thickness by comparing experienced and non-experienced denture wearers after the insertion of new complete dentures. METHODS: Forty edentulous patients with a skeletal Class I jaw relationship without any temporomandibular disturbances were in the study. After insertion of new complete dentures, all patients were tested for discrimination threshold for interocclusal thickness. The thickness perception test was repeated on days 1, 7, and 30 after the insertion of new dentures. The discriminatory ability was assessed with steel and aluminium foils placed between the upper and lower central incisor teeth. The records included the duration of wearing dentures. The data were subjected to statistical analysis of two-way ANOVA, multiple comparison test and Student's t test. RESULTS: Discrimination of tactile ability significantly increased over 30 days in experienced denture wearers as compared with non-experienced patients (P < 0.001). The difference in thickness perception threshold was statistically significant between the two groups (P < 0.001). CONCLUSION: Adaptation and denture experience can affect thickness discrimination of complete denture wearers.