No abstract

Interfacial bond strengths of light-activated composites were measured as a function of age using a transverse strength test. Bond strength between layers decreased with the age of the initial layer and reflected the setting curves of the composites. The highly-filled composites exhibited the greatest bond strengths. Uncut surfaces provided a better substrate for bonding than did ground surfaces. Use of a bonding agent on both uncut and ground surfaces improved bond strengths. Mean repair strengths of light-activated composites were similar to those of self-curing composites. Composites with ground surfaces aged for one wk had mean repair strengths 27% of the cohesive strength without bonding agent and 48% with bonding agent.

The expired air of a group of 48 persons, 40 with and eight without dental amalgam restorations, was analyzed for its mercury content before and after chewing. Expired air samples were collected in polyethylene bags, and a known quantity of each was pumped into the mercury detector for measurement. The results showed that examined subjects with dental amalgams had higher pre-chewing mercury levels in their expired air than those without amalgams. After chewing, these levels were increased an average of 15.6-fold in the former and remained unchanged in the latter group. It was concluded that in situ dental amalgams can increase the level of mercury in expired air.

The purpose of this study was to determine the relationship, if any, of a dental student's 1) state of residency and 2) gender to his or her practice location in a rural Nebraska community after graduation. Previous research has demonstrated that dental students generally locate their practices near their place of rearing and that male graduates are more likely than female graduates to locate in rural areas. Dental student data for all University of Nebraska Medical Center College of Dentistry graduates from 1989 to 2008 (n=879) were analyzed. Descriptive and quantitative analyses were performed utilizing SPSS software (version 17.0). Chi-square and odds ratio analyses were also conducted. In contrast to previous research, women dentists who remained in the state after graduation were more likely to locate their practice in a rural community than were male dentists: 59 percent and 48.5 percent, respectively. Nonresidents who remained in the state after graduation were also more likely to locate in a rural community than were residents: 69 percent and 51 percent, respectively. Dental schools may find this information useful as state officials and policymakers look to dental schools for leadership in addressing dental workforce needs, especially in rural/ underserved areas.

No abstract