A confocal microscopic evaluation of the interface between Syntac adhesive and tooth tissue.

The aim of this study was to microscopically evaluate the effect of dentine smear layer thickness, tubular orientation and immediate stress application on a modern dentine bonding agent. Eighty mesial and distal wedge-shaped cavities were cut into dentine/cementum cervically in 40 extracted human lower third molars. The thickness of the dentine smear layer was reduced by polishing the cavity surface in half the samples. Each component of the bonding agent (Syntac: Ivoclar Vivadent) was labelled with a fluorescent dye, the unfilled resin being light cured for 30 s with the composite restoration placed in one increment and light cured for 40 s. The samples were longitudinally sectioned using a slow speed diamond saw underwater, either immediately or 24 h post placement. The sectioned surfaces were then viewed using a confocal optical microscope. The thickness of the smeared layer only effected the penetration of adhesive in dentine tubules which were separated from the pulp chamber by the cavity design. These areas were well filled with adhesive; however, areas communicating with the pulp chamber showed no penetration differences due to smear layer reduction by polishing. The interdependence of the adhesive components was illustrated by failure to achieve a well-impregnated tooth/adhesive hybrid layer when the materials were incorrectly handled. The Syntac/dentine interface was generally able to withstand the stress of sectioning immediately post placement, but showed signs of failure in the cavity line angle when the applied stresses were greatly increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

The meaning of modern audiological tests in relation to noise-induced deafness: a review

Wilmot, T. J. (1972).Brit. J. industr. Med.,29, 125-133. The meaning of modern audiological tests in relation to noise-induced deafness: a review. If noise-induced deafness becomes a prescribed disease, it is inevitable that a very large number of workers with hearing difficulties will be discovered and will pose serious problems for both industrial medical officers and otologists working in the National Health Service.     

Familial balanced (7;11;21)translocation and Down''s syndrome in two siblings

Cytogenetic studies of a family with two children with Down's syndrome have revealed a balanced reciprocal translocation between chromosomes No. 7, 11 and 21 in the mother. One of three daughters has inherited this translocation. two mongoloid daughters have a supernumerary chromosome No. 21 in addition to the translocation.     

Internet-based screening for Chlamydia trachomatis to reach non-clinic populations with mailed self-administered vaginal swabs

BACKGROUND: Testing for Chlamydia trachomatis by nucleic acid amplification tests (NAATs) using self-collected vaginal swabs (VS) is acceptable and accurate. The objectives were to implement an educational Internet-based program for women to facilitate home screening, to determine whether women would request and use self-collected VS kits, to determine associated risk factors for infection, and to determine satisfaction with the process. METHODS: The website, www.iwantthekit.org, was designed to encourage women > or =14 years to obtain home-sampling kits. Kits could be obtained in the community, requested by Internet/e-mail, or telephone. Users mailed the self-collected VS to the laboratory. Swabs were tested by 3 NAAT assays. Respondents called for results. RESULTS: Forty-one of 400 (10.3%) women were chlamydia positive; 95.1% were treated. Questionnaires indicated 89.5% preferred self-collection, 93.5% rated collection easy/very easy, and 86.3% would use the Internet program again. Black race and age <25 years were associated independently with being chlamydia positive, while use of birth control and non-consensual sex were protective. Thirty-six of 41 (87.8%) positive samples were positive by all 3 NAATs, 5/41 (12.2%) were positive by only 2 NAATs, and none were positive by only 1 NAAT. The Internet/e-mail request method was better than the community pick-up approach because 97.2% of kit requests were e-mailed and 87.5% of kits returned for testing were e-mail requested. CONCLUSIONS: Women will use the Internet to request and use home-sampling kits for chlamydia. NAAT testing performed well on dry-transported VS. High prevalence was detected and questionnaires indicated high-risk sexual behavior.