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.

Comparison of the effects of mandibular protruding devices on obstructive sleep apnoea patients and healthy volunteers.

PURPOSE: To evaluate upper airway diameter differences before and after placement of custom made mandible protruding devices (MPD) in OSAS group and to compare with control group using computerized tomography. METHODS: The OSAS group was composed of 15 patients aged from 25 to 45 years with mild-moderate OSAS and the control group included 15 healthy volunteers, aged from 25 years to 44 years. On coronal and sagittal reformated CT images, anteroposterior (AP) and lateral (LAT) diameters at three levels (passing through soft palate [level 1], 5 mm above uvula [level 2] and 1 cm above the tip of epiglottis [level 3]) were measured before and after MPD placement in both groups. RESULTS: LAT diameters at level 1, level 2 and AP diameter at level 2 in OSAS group were significantly lower than in control group before MPD placement. Only LAT diameters at level 2 in OSAS group were significantly lower than in control group after MPD placement. When we compared upper airway diameters before and after placement of the MPD within each group, statistically significant increase in diameters at all levels were observed. CONCLUSION: MPD is a cheap, easily usable device providing increase in upper airway diameters.