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Elevated proportions of Candida albicans in biofilms formed on dentures are associated with stomatitis whereas Streptococcus mutans accumulation on restorative materials can cause secondary caries. Candida albicans, S. mutans, saliva-derived and C. albicans/saliva-derived mixed biofilms were grown on different materials including acrylic denture, porcelain, hydroxyapatite (HA), and polystyrene. The resulting biomass was analysed by three-dimensional image quantification and assessment of colony-forming units. The efficacy of biofilm treatment with a dissolved denture cleansing tablet (Polident(®)) was also evaluated by colony counting. Biofilms formed on HA exhibited the most striking differences in biomass accumulation: biofilms comprising salivary bacteria accrued the highest total biomass whereas C. albicans biofilm formation was greatly reduced on the HA surface compared with other materials, including the acrylic denture surface. These results substantiate clinical findings that acrylic dentures can comprise a reservoir for C. albicans, which renders patients more susceptible to C. albicans infections and stomatitis. Additionally, treatment efficacy of the same type of biofilms varied significantly depending on the surface. Although single-species biofilms formed on polystyrene surfaces exhibited the highest susceptibility to the treatment, the most surviving cells were recovered from HA surfaces for all types of biofilms tested. This study demonstrates that the nature of a surface influences biofilm characteristics including biomass accumulation and susceptibility to antimicrobial treatments. Such treatments should therefore be evaluated on the surfaces colonized by the target pathogen(s).

This study compares differences by gender in the practice patterns and professional activities of general dentists, specialists, and dentists with Advanced Education in General Dentistry (AEGD) or General Practice Residency (GPR) training. The UCLA School of Dentistry surveyed a random sample of 6,725 dentists graduating from dental school in 1989, 1993, and 1997 as part of an evaluation of the impact of federal funding on postgraduate general dentist (PGD) programs. The survey asked about current practice, services referred and provided, and professional activities. Of the 2,029 dentists (30 percent) who responded, 49 percent were general dentists with no specialty training; 7 percent had AEGD training; 20 percent had GPR training; and 24 percent had specialty training. General dentists were more likely to be in private practice (p<0.05). AEGDs, specialists, and females were more likely to report faculty positions as a secondary occupation. General dentists were more likely to be practice owners than AEGD-or GPR-trained dentists. The mean number of patients seen was highest for specialists. Females reported fewer patients than males, and this difference was significant for GPR-trained dentists. With respect to services, GPR-trained dentists reported significantly more biopsy procedures, conscious sedation, periodontal surgery, and implants than general dentists. AEGD-trained dentists reported more conscious sedation than general dentists. GPR dentists were more likely to volunteer time than general dentists without specialty training. PGD training appears to result in different types of employment and specific practice patterns that strengthen primary care dentistry. We further conclude that there are gender differences in the types of practice, patients seen, and services provided. These findings occur in addition

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