In vivo assessment of the effect of an adhesive for complete dentures on colonisation of Candida species.

OBJECTIVE: Denture adhesives have long been recognised by denture wearers as a useful adjunct to denture retention and stability. The objective of the present study was to evaluate, in vivo, the effect of a denture adhesive on oral quantities of Candida species by determination of absolute counts of colony-forming units (CFU) per ml of saliva of individuals who use this denture adhesive for a period of 14 days. MATERIALS AND METHODS: Twenty-four individuals were randomised in two equal groups of 12 (test and control), with the individuals of the test group using the adhesive for 14 days. Samples of saliva were collected from all individuals on days 0 (initial), 7 and 14. Aliquots of saliva were diluted and plated in duplicate on Sabouraud dextrose agar with chloramphenicol and incubated for 37 °C for 48 h, the CFU/ml were counted in the individuals of each group and the data of each group were compared at the different time periods and analysed statistically by the non-parametric Mann-Whitney U-test (α ≤ 5%). RESULTS: There were no statistically significant differences between the test and control groups during the test periods. CONCLUSION: Within of the limitations of this study, the data suggested that the denture adhesive tested did not significantly alter the oral microbiota during the 14-day trial period.

Effect of a denture cleanser on weight, surface roughness, and tensile bond strength of two resilient denture liners / Efeito do detergente na dentadura pelo peso, superfície rugosa, e força adesiva de tensão de dois revestimentos resilientes na dentadura

Purpose: This study evaluated the effects of a denture cleanser on weight change, roughness, and tensile bond strength on 2 denture resilient lining materials. Material and methods: Forty specimens of microwave acrylic resin (Onda-Cryl), 30 mm in diameter and 4 mm thick, were prepared to verify weight change and surface roughness. The specimens were divided into 4 groups consisting of 10 specimens each, relined with a resilient liner (Coe Soft or Dentusoft), and treated (Polident or tap water). To evaluate tensile bond strength, 12 specimens were used for each group. All specimens were stored in artificial saliva for 15 days, immersed once a day in Polident or tap water, and evaluated at 0 hours and after 24 hours and 7 and 15 days. Roughness was evaluated by use of a profilometer. Weight changes were recorded in milligrams and expressed as the percentage of weight difference between the periods of evaluation. Tensile bond strength was determined with a universal testing machine. The specimens were placed under tension until failure by a cross-speed of 5 mm/min with a 500 Kg load cell. The type of failure was determined by use of stereoscopic microscopy at original magnification ž8. The data were submitted to analysis of variance and compared by Tukey's test (alfa=.05). Results: Specimens immersed in Polident showed higher and significant (P<.05) weight changes (percent) than those immersed in water between 24 hours and 7 days (Coe Soft-Polident: 0.48 ± 0.09; Coe Soft-water: 0.28 ± 0.09; Dentusoft-Polident: 0.44 ± 0.16; Dentusoft-water: 0.22 ± 0.15) and between 7 and 15 days (Coe Soft-Polident: 0.08 ± 0.04; Coe Soft-water: - 0.17 ± 0.05; Dentusoft-Polident: 0.01 ± 0.04; Dentusoft-water: - 0.24 ± 0.03). There was significant difference (P<.05) in roughness (in micrometers), between treatments after 7 days (Coe Soft-water: 4.07 ± 0.22; Coe Soft-Polident: 3.36 ± 0.52; Dentusoft-water: 3.68 ± 0.72; Dentusoft-Polident: 3.26 ± 0.41) and 15 days (Coe Soft-water: 4.88 ± 0.29; Coe Soft-Polident: 3.53 ± 0.61; Dentusoft-water: 4.42 ± 1.12; Dentusoft-Polident: 3.68 ± 0.37). Tensile bond strength was highest (P<.05) after 15 days (Coe Soft-water: 5.19 ± 0.93; Coe Soft-Polident: 4.40 ± 0.38; Dentusoft-water: 4.42 ± 1.15; Dentusoft-Polident; 4.84 ± 1.14). Most failures were cohesive (Coe Soft: 76.04 percent and Dentusoft: 82.29 percent)...