OBJECTIVETo prepare a new synthetic macromolecular resin class of denture adhesive (named Comfort-DA).

METHODSTwelve different formulae for denture adhesive were designed by orthogonal design. Each factor affecting tensile bond strength of adhesive was analyzed by ANNOVA to select the best formula. Then the chemical and physical properties, such as tensile bond strength, pH value, and viscosity, were evaluated and compared with Fittydent in vitro also.

RESULTSThe effect of content of polyvinyl acetate and cellulose ether on tensile bond strength exhibited no statistical significance (P > 0.05), while ethyl alcohol and CMC-Na showed statistical significance and mutual action (P < 0.05). Results of testing viscosity and shearing stress showed that there was no significant difference between Fittydent and Comfort-DA (P > 0.05), while Fittydent exhibited a significantly lower tensile bond strength than the prepared one (P < 0.05). The prepared adhesive demonstrated a neutral or slightly basic pH.

CONCLUSIONSThe generally favorable in vitro performance of the prepared adhesive (Comfort-DA) formulation indicated that it might be efficacious denture adhesive.

Adhesives ; chemistry ; Composite Resins ; chemistry ; Dental Bonding ; Denture Retention ; methods ; Humans ; Hydrogen-Ion Concentration ; Tensile Strength

Objective To investigate the prevalence rate of healthcare-associated infection(HAI)in Xiangya Hospital,and provide reference for preventing and controlling HAI.Methods The cross sectional surveys on preva-lence rates of HAI,cross-sectional antimicrobial use,and bacterial detection among all hospitalized patients on the given days in 2000-2014 (except 2006)were carried out by combination of bedside investigation and medical record reviewing.Results The prevalence rates of HAI in 2000-2014 decreased from 6.30% to 3.91%,difference was statistically significant (χ2 = 35.14,P < 0.001 );prevalence rates of community-associated infection(CAI)were 15.61%-15.76%,there was no significant difference among each year.General intensive care unit (ICU)had the highest prevalence rate;respiratory tract was the most common site of both HAI and CAI;urinary catheterization rate showed a decreased tendency,arteriovenous catheterization rate showed a increased tendency,difference were both significant(χ2 = 5.21,96.24,respectively,both P <0.001).In 2008 - 2014,pathogenic detection rates for specimens from patients receiving therapeutic antimicrobial agents were 36.37%-44.51%,from patients with HAI were 34.00%-44.99%,detection rate of pathogens causing HAI were 41.57%-68.48%,all showed a increased tendency,difference was significant (χ2 = 22.78,10.03,26.49,respectively,all P < 0.001 ).Gram-negative bacteria were the main pathogens causing infection;both cross sectional and combination antimicrobial usage rates declined (P < 0.05 ).Conclusion Prevention and control of HAI,and antimicrobial management has achieved preliminary success,prevalence rate of HAI and cross sectional antimicrobial usage rate declined obviously,the main pathogen is gram-negative bacteria,and the major infection site is lower respiratory tract.