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Biomedical subjects

L Geary

Publications and source records attributed to L Geary.

6 recordsLinked to original sources

Seatbelt use by high school students.

OBJECTIVE: To determine seatbelt use of teenage drivers arriving at high schools in the morning and at evening football games compared with belt use of adults driving teenage passengers to these events, and teenage passenger belt use depending on whether they were being driven by another teenager or an adult. METHODS: Unobtrusive observations of belt use were made at 12 high schools in Connecticut and Massachusetts. RESULTS: Among males, teenage drivers had lower belt use than adults; differences between female teenage and female adult drivers were slight. Teenage passengers had lower belt use in vehicles driven by other teenagers than in cars driven by adults, but more than 40% of teenage passengers in vehicles driven by adults, presumed in most cases to be the teenager's parent, were not belted. Teenage passenger belt use was lower than teenage driver use regardless of gender. These differences were found both at morning arrivals and at football games, but teenage belt use was not much different in these two settings. Teenage passengers were belted more often if drivers were belted, whether the driver was another teenager or an adult, but a third of male passengers and 25%-30% of female passengers were unbelted even when drivers were belted. CONCLUSION: Teenagers have high crash risk but low belt use, which adds to their injury problem. Avenues to address this include strong belt use laws and their enforcement, building belt use requirements into graduated licensing systems, keeping young beginners out of high risk driving situations, and finding ways to influence parents and other adults to ensure that their teenage passengers use seatbelts.

Adolescent↗

Retention of adhesive cement on the tooth surface after crown cementation.

STATEMENT OF PROBLEM: Adhesive cements increase crown retention, but it is unknown if traces of cement remain undetected on the tooth surface after clinical removal of excess cement, which could exacerbate plaque retention. PURPOSE: This study measured the surface area, volume, mean depth, and maximum depth of a resin composite and a compomer luting cement left adherent on the tooth surface after removal of excess cement, as judged clinically. METHODS AND MATERIAL: Four groups of specimens (n = 48) were prepared for full coverage crowns: group AC bonding alloy with chamfer finish line, group G gold alloy with chamfer finish line, group PC porcelain with a chamfer finish line, and group PS porcelain with a shoulder finish line. Two profiles of the mesial and distal surfaces of the teeth were carried out: (1) tooth with crown seated but not cemented and (2) tooth with the crown cemented in place. Two cements and 2 methods of cement removal were studied. RESULTS: A 4-way analysis of variance for cement, crown type, method of removal, and tooth surface morphology showed that significantly greater volumes and mean depth, but not surface areas, of resin composite cement remained adherent than compomer cement (P<.05). Among crown types, significant differences were found for cement volume (group G>AC, G>PC, G>PS), cement surface area (group AC>PC, G>PC, G>PS), and maximum cement depth (group G>AC). There was no significant difference between the 2 methods of cement removal. Significantly larger surface areas and maximum depths of cement were retained on the anatomically grooved mesial surface of the maxillary first premolars than on the ungrooved distal surface. CONCLUSION: Subclinical cement retention occurred after crown cementation, which was influenced by cement, crown type, and tooth surface morphology but not method of cement removal.

Adhesives↗

A preliminary study of patient comfort associated with customised mouthguards.

OBJECTIVE: To compare patient perception of custom made mouthguards of ideal and less than ideal designs in terms of their comfort and "wearability". METHOD: A mouthguard of ideal design (A) and one incorporating common design faults of underextension and unadjusted occlusion (B) were provided for 22 active sportsmen and women. They were not informed of the details of the design or the status of the protector. Half the participants were asked to wear mouthguard A first and the other half wore B first, each worn for one hour on two consecutive nights. Questionnaires were used to evaluate and rate the comfort and wearability of each mouthguard. RESULTS: Eighteen people completed the study. The ideal appliance was rated as significantly more retentive and comfortable overall and specifically was more comfortable to lips, gums, and tongue. It was also recognised as being less bulky, less likely to keep the teeth apart, or to cause pain in the jaw muscles. CONCLUSIONS: Comfort is likely to be increased if mouthguards are extended labially to within 2 mm of the vestibular reflection, adjusted to allow even occlusal contact, rounded at the buccal peripheries, and tapered at the palatal edges.

Adult↗