The permeability of human dentine in vitro and in vivo

Experiments in cats have shown that Evans blue dye diffuses at a greater rate into dentine in recently extracted teeth than in vivo. These experiments have now been repeated in man and similar results were obtained except that, after applications in vivo, visible concentrations of the dye were present in the dentine, and in a few cases, even in the pulp. It is concluded that, as in the cat, the diffusion in vivo was impaired by outward flow of fluid in the dentinal tubules but the mean velocity of flow in the human dentine was less than that in the cat.

Insects as teaching tools in primary and secondary education

Insects offer a vast array of teaching opportunities for precollege students. Here we address the basics teachers need in order to use insects successfully in their curricula. We identify exemplary resources in the printed North American literature and point out potentially productive places for teachers and students to search for ideas and materials. We review the roles of entomology in the educational framework, highlight favorite classroom arthropods and less well-known examples, and guide readers to entomological resources. Tips to help teachers identify, rear, and maintain classroom insects and find equipment and supplies are included. The review concludes with a plea for greater classroom and curricular involvement by those in the entomological profession.

Chronic lymphocytic leukaemia with gingival and palatal deposits

The oral features of a patient with notable maxillary and mandibular gingival enlargement secondary to leukaemic infiltration in chronic lymphocyte leukaemia are presented.

Working patterns of male and female dentists in the UK

A random selection of male (250) and female (250) dentists in the Dentists Register 1992 were sent a postal self-administered questionnaire to determine their working patterns, places of work and whether or not they had children of school age or younger. There was also space for free comment. Responses from 75% of males and 81% of females were received. Results show that 79% of males, compared with 46% of females, work in full-time dentistry, chiefly in general dental practice. Family commitments were the principal reason for 30% of female dentists working part-time. A small number (14%) of male dentists work in a second career alongside part-time dentistry. As a female dentist's family becomes older and less dependent so the number of sessions worked increases. Overall, female dentists felt well suited and satisfied with their chosen profession. A small, but worrying group (4%) of male full-time general dental practitioners were very dissatisfied with dentistry as a career and showed clear signs of severe psychological stress expressed in the style and nature of free comments made.

The efficacy of management of acute dental pain

The effectiveness of pain relieving treatments given for acute dental pain has been evaluated after 24 hours in 172 patients who presented to a dental hospital emergency department. Patients were contacted by telephone the day after attendance and graded their pain on a scale from 1 (no pain) to 5 (pain much worse). The mean pain scores for each diagnosis of cause of pain were calculated and related to the treatment given. Some 76% of patients were in pain due to the ravages of dental caries of periodontal disease. Overall, 87% received marked or total pain relief and this appeared to depend upon decompression of inflamed tissue. Oral administration of antimicrobial drugs alone produced little or no pain relief within 24 hours and anti-inflammatory analgesics offer poor pain control in these circumstances.

Recent trends in university entry for dentistry in the UK

The pattern of university applications has been related to dental school application rates between 1985 to 1991. The academic standard of GCE 'A' level attainment acceptable to each school has also been related to the number of places available and number of places filled. Whilst the total number of university applications has increased over the period, dental applications have decreased, with a lower proportion of male applicants being noticeable. Some schools had lower application rates than others. There appeared to be a tendency for schools which had previously accepted slightly lower 'A' level standards for entry to receive a larger number of applicants. Some schools showed evidence of accepting lower 'A' level standards of entry presumably to meet the financial need to fill all available places.

Pulse oximetry during minor oral surgery with and without intravenous sedation

This study investigated the levels of oxygen saturation and pulse rates of patients undergoing minor oral surgery under local analgesia, with (20 patients) or without (20 patients) intravenous sedation with midazolam. The results indicated that a statistically significant fall in arterial blood oxygenation of 1% to 2%, as measured by pulse oximetry, followed midazolam administration; however, this was physiologically insignificant. Both groups showed a similar postoperative small fall in oxygen saturation. Transient episodes (24 to 36 seconds) of physiologically significant mild hypoxia occurred during breath holding, but this condition was readily corrected by encouraging patients to breathe deeply. Midazolam had a small but significant calming effect on the higher preoperative pulse rates exhibited by anxious patients, but this effect was not sustained during the operating period. Both sedated and unsedated patients showed episodes of tachycardia that could have significance for patients with cardiac disease.

Cardiopulmonary resuscitation skills of dental personnel

This study assessed the cardiopulmonary resuscitation (CPR) skills of 25 dental personnel. Theory was tested by multiple choice questionnaire (MCQ) and practical skills assessed using a recording Resusci-Anne manikin. The assessment was based upon the recommendations of the Resuscitation Council of the UK. Seven of the 16 dental students and six of the nine house officers tested passed the MCQ examination. All failed the practical assessment. It is concluded that more emphasis should be placed upon CPR instruction in undergraduate dental courses and that regular update courses are advisable to maintain CPR skill.

A study of the comparative efficacy of four common analgesics in the control of postsurgical dental pain

Four common oral analgesics were tested in a single-blind trial to determine their relative efficacy in the management of postsurgical pain in 103 patients who had their impacted third molars surgically removed under general anesthesia. The analgesics tested were acetylsalicylic acid (26 patients), ibuprofen (26 patients), a paracetamol/codeine/caffeine combination (Solpadeine) (25 patients), and dihydrocodeine (26 patients). The paracetamol/codeine/caffeine combination, ibuprofen, and acetylsalicylic acid preparations produced equally effective analgesia. Dihydrocodeine was found to be a poor analgesic in this pain model. There were no adverse reactions to any of the preparations.

Where are we going?

As medicine and dentistry have grown in complexity, so has the nature of the relationship between the two sciences. With increasing financial pressures and declining in-takes to dental schools, Robin Matthews argues that both disciplines would gain through a closer, more coordinated liaison.

Roxithromycin as a possible agent for prophylaxis of endocarditis: a study in normal volunteers

A single dose of roxithromycin, 300 mg, was taken by six healthy male volunteers on three occasions at consecutive weekly intervals. It was well tolerated. On the first two occasions, roxithromycin was assayed in serum samples taken at intervals up to 8 h after the administration. The mean peak concentration at 1 h was 3.0 mg/l (range 0.3-7.3). The serum samples from the volunteers showed variable bactericidal activity against a strain of Streptococcus sanguis isolated from a case of bacterial endocarditis. Roxithromycin was not detected in saliva or gingival fluid. Smooth surface plaque samples taken at intervals were investigated for the emergence of streptococci resistant to roxithromycin at 2 and 8 mg/l. Initially two volunteers had small number of roxithromycin-resistant streptococci. At the end of the study all six volunteers had resistant streptococci detectable in their plaque samples and these accounted for 100% of the streptococci in two volunteers. The most resistant isolates (in several cases with MIC greater than 64 mg/l) were Str. sanguis or Str. mitior; individual volunteers tended to yield the same strain on consecutive samplings.

Nesting Biology and Taxonomy of Arpactophilus-Mimi, a New Species of Social Sphecid (Hymenoptera, Sphecidae) From Northern Australia

Arpactophilus mimi, Naumann, sp. nov., is described from Kakadu National Park, N.T. and its biology is outlined. A. mimi nests in abandoned cells of mud-dauber wasps in sandstone overhangs. Its nests are lined heavily with silk and contain 1-15 cells and 1-10 adult wasps (1-7 females, 0-3 males). On average nests contain 5.2 cells and 2.75 adult females. Prey (immature Psyllidae and Tingidae) are supplied progressively. Nests are parasitised by a species of megalyrid wasp, but incidence of parasitism is low. Nest defense is both physical (entrance guard always present) and chemical (citrus odour from heads of both sexes). Females from a single nest could be ranked on the basis of relative ovarian development, suggesting that more than one female oviposits. Females apparently cooperate in brood care and offspring in a nest develop asynchronously. The biology of A. mimi is compared to that of Microstigmus comes Krombein, the most socially advanced sphecid known, and selective pressures that may have acted to promote female cooperation in the two genera are discussed. For A. mimi the lack of available nest sites could be an important factor restricting the ability of offspring to disperse and establish nests.

Clinical evaluation of benzydamine, chlorhexidine, and placebo mouthwashes in the management of recurrent aphthous stomatitis

Eighteen patients with minor recurrent aphthous stomatitis were given alcoholic benzydamine hydrochloride, aqueous chlorhexidine, or a benzydamine-free placebo mouthwash in random order. Each patient used each preparation for a 3-month period. Ulcer diaries were marked at the same time each week during the 9-month test period. Records were made of the number, size, sites, and pain severity of any ulcers present. Statistical analysis of the results showed no significant differences between any of the treatments tested. Stinging of the oral mucosa was the only consistent side effects noted by nine patients using benzydamine, nine patients using placebo, and three patients using chlorhexidine. Eight patients stated a personal preference for benzydamine because of the transient local anesthetic effect of benzydamine, which gave pain relief.