Biomedical subjects

G Byrne

Publications and source records attributed to G Byrne.

75 records · Page 5Linked to original sources

PubMedDate not supplied

Environmental factors affecting mechanical properties of facial prosthetic elastomers.

This study evaluated the degradation of elastomers for facial prostheses exposed to environmental factors normally present in a service environment. Two silicone elastomers and a polyurethane were evaluated. Samples were exposed to ultraviolet radiation, simulated sebum, ozone, chlorine, and nitrogen dioxide, and tested for tear propagation and resistance. Test results revealed significant differences in the tear characteristics between silicones and polyurethane. Differences in tear patterns were observed between the control and the specimens exposed to environmental factors. The environmental factors affected the polyurethane Epithane-3 the most and silicone MDX 4-4210 the least. When exposed to chlorine and nitrogen dioxide, Cosmesil and Epithane-3 were degraded to a point where sample testing was not possible. When exposed to ultraviolet radiation, Epithane-3 was degraded and could not be tested. Simulated sebum and ozone affected Cosmesil and Epithane-3, but no clear trends were observed.

Analysis of Variance↗

PubMedDate not supplied

Influence of finish-line geometry on the fit of crowns.

Previous studies on the fit of complete crowns have neglected to assess the internal adaptation of castings prior to cementation. Theoretical arguments and laboratory studies have failed to clarify which is the most desirable finish-line configuration in terms of marginal fit. This study evaluated axial and marginal fit of crowns made for three tooth preparations that had different labial finish-line configurations: shoulder, shoulder-bevel, and chamfer. The crowns were not cemented, but were sectioned and examined on their respective dies. There were no significant differences (P < or = .05) among groups for marginal or axial gaps. Crown fit was not influenced by any of the three finish lines tested, and castings with well-fitting margins exhibited measurable axial wall space.

Analysis of Variance↗

PubMedDate not supplied

Use of seat belts in a Dublin area.

This study examines public compliance with seat belt regulations. Two busy suburbs in north Dublin were studied. Of the 2,139 vehicles surveyed 1,160 (54.2%) drivers wore a seat belt. Young female drivers were most likely to comply with the regulations (70.1%). Only 344 (46.1%) front seat passengers wore their seat belt. 188 children who appeared to be under 10 years of age were observed in the front seat of vehicles and of those just 9 babies were appropriately restrained. Of the back seat passengers 108 (19.2%) wore seat belts; 99 (21.8%) children and 9 (9.8%) adults. Despite on-going publicity and progression in the regulations our use of seat belts is grossly disappointing. Road traffic accidents exert an unacceptably high toll on health in Ireland. Seat belts are known to be effective in preventing serious injury. A much greater emphasis on enforcement of legislation is now urgently needed to encourage responsible behaviour among vehicle users and to reduce the needless suffering due to road traffic accidents.

Adolescent↗