Continuing dental education in radiation protection: knowledge retention following a postgraduate course.

OBJECTIVE: To evaluate medium-term knowledge retention of dental personnel following attendance at a postgraduate course in radiation protection. SUBJECTS AND METHODS: Knowledge was measured using identical pre- and post-course validated single best-answer multiple-choice instruments, administered immediately before and after training and at follow-up at 6 or 12 months. These comprise 16 questions each with 5 choices. The range of possible scores was from 0 to 16, and scores were scaled to percentages. Participants were predominantly dental practitioners, but a minority consisted of dental care professionals (dental nurses, hygienists and therapists). Of 285 participants, 272 (95.4%) completed both pre- and post-course questionnaires. One hundred and seventeen (43%) of these also completed the follow-up test, but only 109 (40%) individuals could be linked to the original course. RESULTS: Mean (standard deviation) pre-, post-course and follow-up-corrected percentage scores were 39.1 (16.1), 74.6 (16.9) and 58.9 (22.7), respectively. There was attrition in knowledge at follow-up: the average increase in adjusted score after training was 35.5 points, but only 56% of this was retained at follow-up. Paired t-tests confirmed that the mean score at follow-up was firmly intermediate between the pre- and post-course scores. Of the 109 participants, 7 (6%) achieved a satisfactory score pre-training, 82 (75%) immediately post-training and 41 (38%) at follow-up. There were gross differences between the levels of performance achieved for the eight subject areas tested. CONCLUSION: Immediate post-course assessments have indicated that current postgraduate courses in radiation protection are effective. However, a substantial amount of knowledge is lost by 6-12 months following course attendance. To achieve long-term knowledge retention, early or repeated reinforcement may be necessary.

Bilateral mandibular condylysis in a patient with systemic sclerosis.

A case of progressive osteolysis of the mandibular condyles in a 55-year-old female patient with systemic sclerosis (SSc) is described. Orofacial involvement and radiological manifestations of SSc are discussed.

The effectiveness of dental postgraduate courses--are we doing the right thing?

OBJECTIVE: To evaluate the effectiveness of dental postgraduate one-day courses in radiation protection in Wales. DESIGN: Analysis of dentists' performance pre- and immediately post-course training. SUBJECTS AND METHODS: Two hundred and eighty-five general dental practitioners took part in eight courses. Identical, validated multiple choice questionnaires were completed anonymously at the start and at the end of each course. Fifty (+62.5%) or above was regarded as a satisfactory standard. Two hundred and fifty-three (89%) paired morning-afternoon records were completed and analysed. Data was compared to that of similar courses five years earlier. RESULTS: The mean (SD) pre- and post-course percentage scores were 33.8 (13.5) and 63.6 (14.6). The mean improvement was 29.8 percentage points (SD 11.7). The pre-post correlation was +0.66. At baseline only six (2.4%) of the 253 practitioners achieved the preset standard. After the course, 146 (57.7%) did so, an improvement of 55.3% (95% CI 48.9-61.3%). The final score and score gain were slightly higher in more recent graduates. The increase in proportion attaining the standard following training was 11.9% higher for IRMER than for POPUMET (p <0.001). CONCLUSION: The level of knowledge in radiation protection was very low at baseline. Whilst attending the approved course led to considerable improvement, it did not invariably result in a satisfactory level of knowledge in fundamental radiation physics and regulations. The prescribed standard was achieved by less than 60% of the attendees. The IRMER course was significantly more effective than its POPUMET predecessor.

An outcome audit of the treatment of acute dentoalveolar infection: impact of penicillin resistance.

OBJECTIVES: The aim of this audit was to measure the outcome of treatment of acute dentoalveolar infection and to determine if this was influenced by choice of antibiotic therapy or the presence of penicillin-resistance. SUBJECTS AND METHODS: A total of 112 patients with dentoalveolar infection were included in the audit. All patients underwent drainage, either incisional (n=105) or opening of the pulp chamber (n=7) supplemented with antibiotic therapy. A pus specimen was obtained from each patient for culture and susceptibility. Clinical signs and symptoms were recorded at the time of first presentation and re-evaluated after 48 or 72 h. RESULTS: A total of 104 (99%) of the patients who underwent incisional drainage exhibited improvement after 72 h. Signs and symptoms also improved in five of the seven patients who underwent drainage by opening of the root canal although the degree of improvement was less than that achieved by incisional drainage. Penicillin-resistant bacteria were found in 42 (38%) of the 112 patients in this study. Of the 65 patients who were given penicillin, 28 had penicillin-resistant bacteria. There was no statistical difference in the clinical outcome with regard to the antibiotic prescribed and the presence of penicillin-resistant bacteria. Strains of penicillin-resistant bacteria were isolated more frequently in patients who had previously received penicillin (p<0.05). CONCLUSION: Incisional drainage appeared to produce a more rapid improvement compared to drainage by opening of the root canal. The presence of penicillin-resistant bacteria did not adversely affect the outcome of treatment. The observations made support surgical drainage as the first principle of management and question the value of prescribing penicillin as part of treatment.

Prevention of brain protein and lipid oxidation elicited by a water-soluble oryzanol enzymatic extract derived from rice bran.

BACKGROUND: The antioxidant capacity of rice bran (RB) (due mainly to its gamma-oryzanol content) is very well known. We have recently developed a water-soluble oryzanol enzymatic extract (WSOEE), which shows a greatly increased functionality. AIM OF THE STUDY: The aim of our study is the evaluation of the antioxidant potential of WSOEE in an ex vivo model to compare its protective capacity against oxidative damage by active-oxygen substances and free radicals (mainly the peroxyl radical) to biomolecules (such as proteins and lipids) with that of antioxidants, such as Trolox (a water-soluble derivative of vitamin E), melatonin, and folic acid. METHODS: WSOEE gamma-oryzanol content and composition were determined by HPLC. Free-radical-scavenging capacity was evaluated using the assay based on phycoerythrin fluorescence. Antioxidant capacity against hydroperoxide-caused oxidative injury to proteins and lipids was evaluated using an ex vivo model: a rat brain homogenate. The effectiveness was determined by assessing protein damage (measured as carbonyl group content by Western blot immunoassay) and lipid peroxidation (measured as malondialdehyde content). RESULTS: The WSOEE gamma-oryzanol composition profile was similar to that of RB (cycloartenyl, 24-methylene cycloartenyl, campesteryl, and sitosteryl ferulates), but with two major differences: WSOEE gamma-oryzanol concentration was five times higher than that of RB, and WSOEE was water soluble. WSOEE total antioxidant capacity to trap the peroxyl radical was high, and similar to that of Trolox. The capacity to inhibit lipid peroxidation induced by cumene hydroperoxide in rat brain homogenate yielded a protection similar to that of Trolox. WSOEE also showed the capacity to protect protein from oxidation phenomena in rat brain homogenate, with a behavior similar to that of melatonin. This is of particular importance, since the loss of protein function caused by oxidative modification may affect the activity of enzymes, receptors, and membrane transporters, among other functions. CONCLUSION: WSOEE is a new potential antioxidant agent from rice bran that shows a high free-radical-scavenging capacity and prevents protein oxidation and lipid peroxidation when cells ex vivo are exposed to free radicals.

"In vitro" effect of cumene hydroperoxide on hepatic elongation factor-2 and its protection by melatonin.

We have examined by immunoblotting the effect of three oxidant compounds on the level of hepatic elongation factor-2 (eEF-2). Rat liver homogenates were exposed to cumene hydroperoxide (CH), 2-2'-azobis (2-aminopropane) dihydrochloride (AAPH) and H(2)O(2). Only CH treatment produced the disappearance of eEF-2, probably due to a phenomena of peptide bond cleavage. The direct implication of free radical species in this process is evident because of the fact that the inclusion of a free radical scavenger such as melatonin prevented the eEF-2 depletion. The results also suggest that the disappearance of eEF-2 induced by CH can be linked to a lipid peroxidant process, which could account for the decline of protein synthesis in aging and other circumstances where lipid peroxidation is high.

Protective effect of melatonin against the 1-methyl-4-phenylpyridinium-induced inhibition of complex I of the mitochondrial respiratory chain.

In the present study, a novel property of melatonin is shown: a protective effect of melatonin on the respiratory chain in isolated rat liver mitochondria and in striatal synaptosomes treated with 1-methyl-4-phenylpyridinium ion (MPP+). The cellular damage caused by MPP+, a compound that produces a Parkinsonian-like syndrome in humans, is the result of the mitochondrial respiration inhibition at the Complex I level and oxidative stress induction. Treatment of mitochondria with MPP+ inhibits the respiration rate. This effect was prevented by the inclusion of melatonin in the incubation mixture. This preventive effect, which is not related to the antioxidative properties of melatonin, seems to be due to the fact that melatonin prevents MPP+ interaction with Complex I. These results suggest that melatonin may protect against the effect of several Parkinsonogenic compounds that are associated with progressive impairment of mitochondrial function and increased oxidative damage.

The endogenous amine 1-methyl-1,2,3,4- tetrahydroisoquinoline prevents the inhibition of complex I of the respiratory chain produced by MPP(+).

The endogenous monoamine 1-methyl-1,2,3,4-tetrahydroisoquinoline has been shown to prevent the neurotoxic effect of MPP(+) and other endogenous neurotoxins, which produce a parkinsonian-like syndrome in humans. We have tested its potential protective effect in vivo by measuring the protection of 1-methyl-1,2,3,4-tetrahydroisoquinoline in the neurotoxicity elicited by MPP(+) in rat striatum by tyrosine hydroxylase immunocytochemistry. Because we know that cellular damage caused by MPP(+) is primarily the result of mitochondrial respiratory inhibition at the complex I level, we have extended the study further to understand this protective mechanism. We found that the inhibitory effect on the mitochondrial respiration rate induced by MPP(+) in isolated rat liver mitochondria and striatal synaptosomes was prevented by addition of 1-methyl-1,2,3,4-tetrahydroisoquinoline. This compound has no antioxidant capacity; therefore, this property is not involved in its protective effect. Thus, we postulate that the preventive effect that 1-methyl-1,2,3,4-tetrahydroisoquinoline has on mitochondrial inhibition for MPP(+) could be due to a "shielding effect," protecting the energetic machinery, thus preventing energetic failure. These results suggest that this endogenous amine may protect against the effect of several parkinsonism-inducing compounds that are associated with progressive impairment of the mitochondrial function.

The appropriateness of referral of medically compromised dental patients to hospital.

Hospital departments of oral and maxillofacial surgery make a substantial contribution to both managing and treating medically-compromised dental patients. Contracting arrangements should take account of this. Demographic data suggest that the treatment of medically-compromised elderly dentate patients will become increasingly important in the General Dental Service (GDS). To determine the medical conditions and treatment requirements prompting referral of these patients to hospital, a prospective study was undertaken of 75 consecutive adults referred for hospital treatment specifically because of a medical condition which prevented delivery of routine dental care in the GDS. Patients (mean age: 56 years) were referred mainly from general medical (33%) and dental (62%) practitioners. Cardiovascular disease was the most frequently cited medical condition requiring referral (43%; n = 32 cases). Forty-eight patients (64%) were symptomatic on presentation and on average had attended on 2.3 occasions before definitive treatment was instituted. Fifty-two patients (70%) had no special treatment requirements other than those available in the GDS, 11 patients (15%) simply required antibiotic prophylaxis and 81% were treated by undergraduates or junior staff. These data suggest that many patients referred for dental hospital treatment because of underlying medical condition are not in fact medically-compromised and may be treated in the primary care setting.

Antibiotic prescription for acute dental conditions in the primary care setting.

To determine the pattern of antibiotic prescribing (source and type) for acute dental conditions in the emergency setting, a prospective cross-sectional study was undertaken of 500 consecutive new patients attending the examination and emergency clinic of the Cardiff Dental Hospital in May 1994. The source and type of antibiotics prescribed, the nature of complaint and type of antibiotic prescribed in the primary care and dental hospital setting were recorded. Antibiotic prescription was a feature of the treatment of 30% (149/500) of patients. The 60 patients who had received emergency treatment prior to attending the hospital emergency clinic had been prescribed a total of 14 different types of antibiotics; 41% of these patients had sought treatment from general medical practitioners. Antibiotics were frequently prescribed without generally accepted criteria and there was wide variation in prescribing. Overall, only seven different types of antibiotics were prescribed in the dental hospital setting. The use of second generation antibiotics was more common in general practice than in the dental hospital. The results suggest that many patients with dental pain may seek treatment from medical practitioners, prior to, or in place of, definitive dental treatment. In summary, rationalisation of antibiotic prescription and the provision of emergency dental treatment is needed.

Oral presentation of metastatic calcinosis cutis.

An 80-year-old man presented with a hard swelling in the lower labial sulcus. Radiological investigation showed a mineralized mass on the labial aspect of an edentulous mandible which on excision, demonstrated the histological features of calcinosis cutis. No other sites seemed to be affected by calcific deposits in this patient, who appears to be the oldest reported case of metastatic calcinosis, and the first intra-oral case, to date. The different forms of calcinosis cutis are highlighted.

Prevalence of penicillin resistant bacteria in acute suppurative oral infection.

Pus aspirated from acute suppurative oral infections in 78 patients (age range 13-76 years) yielded a total of 331 bacterial strains consisting of 143 facultative anaerobes (predominantly Streptococcus spp.) and 188 strict anaerobes (predominantly Prevotella spp.). Seventy-five isolates (23%) were resistant to penicillin (MIC > 1 mg/L), 37 (11%) were resistant to ampicillin (MIC > 2 mg/L) and 16 (5%) isolates were resistant to amoxycillin/clavulanic acid (MIC > 2 mg/L). Samples from 43 (55%) of the patients yielded at least one penicillin resistant isolate and within this group 30 samples (73%) contained at least one strain which produced beta-lactamase. A history of antibiotic therapy during the 6 months before enrollment in the study did not influence the isolation of penicillin resistant bacteria. It is concluded that penicillin resistant bacteria are often present in the microflora of acute dental infection.

The location and tracking of swallowed dental appliances: the role of radiology.

Two cases of swallowing mishaps, one involving a spoon-denture and the other an orthodontic partial arch wire, are reported. The former was recovered following interventional radiology, the latter by proctoscopy. The role of radiographic investigation and possible measures to prevent such potential life-threatening emergencies are discussed.

Dentine hypersensitivity: uptake of toothpastes onto dentine and effects of brushing, washing and dietary acid--SEM in vitro study.

Toothpastes are commonly used in the treatment of dentine hypersensitivity. One mode of action could be to block patent dentinal tubules with toothpaste ingredients or by abrasion to form a smear layer. Studies in vitro have shown that toothpaste abrasives have variable affinity for the dentine surface but retention may be limited. This SEM study extended previous work and determined the uptake in vitro of toothpaste ingredients onto the dentine surface and their retention when challenged by washing with water or orange juice. All products were seen to leave variable residues on the surface of etched or unetched dentine specimens, furthermore brush application produced some smearing with closure of previously open tubules. Washing with water and more particularly orange juice removed most residues and orange juice etched the dentine to open previously closed tubules. One product with an artificial silica abrasive was relatively resistant to both water and orange juice washings and in a pilot experiment showed some penetration into tubules not seen with another desensitizing product. These findings suggest that some abrasives may be usefully employed in desensitizing products, but without consideration of erosive factors in the aetiology of dentine hypersensitivity recurrences of the condition will be common.

The demand for primary dental care at a dental teaching hospital, 1989 and 1993.

The demand for, and provision of, primary dental care was investigated in a teaching hospital setting in 1989 and 1993 - a period which saw the introduction of the new dental contract and the publication of the Poswillo report on general anaesthesia and sedation. Five hundred patients who attended the primary care department for the first time at the University of Wales Dental Hospital were interviewed in May/June 1989, and a further 520 patients were interviewed in May/June 1993. Self-referrals increased from 260 patients (52%) in 1989 to 352 patients (68%) in 1993. The proportion of patients who did not have a general dental practitioner (GDP) increased from 32% (160) in 1989 to 39% (202) in 1993. More patients registered with a dentist self-referred in 1993 compared to those in 1989, reportedly because of inability to obtain an appointment with their own GDP (88), rather than because of cost (17). Over the four-year period there was an increase in demand for treatment of early stage (pulpitic) dental infection from 32% to 40%, and a decrease in relation to end-stage infection (dentoalveolar abscess) from 11% to 6%. This 'safety net' role of dental hospitals needs to be taken into account when contracting for services.

Odontogenic keratocyst involving the maxillary sinus: report of two cases.

The occurrence of odontogenic keratocysts in the maxilla is relatively rare, and invasion of the maxillary sinus unusual. Such cysts are normally small and unilocular. Two large keratocysts with different clinical features and radiological appearances, which had invaded the sinus, are discussed in the case reports presented here. It is suggested that if clinical signs and symptoms are absent, the radiological appearance on both conventional and panoramic radiography may be misinterpreted.

An unclassified Eubacterium taxon in acute dento-alveolar abscess.

The microflora of pus samples aspirated from 50 acute dento-alveolar abscesses was examined. A total of 143 bacterial strains was isolated, consisting predominantly of Prevotella spp., alpha-haemolytic Streptococcus spp., Peptostreptococcus spp. and Eubacterium spp. An unclassified asaccharolytic Eubacterium taxon was encountered in 17 (34%) of the abscesses. This taxon was found to have a positive association with Fusobacterium spp. and a negative association with alpha-haemolytic Streptococcus spp.

Bronchogenic carcinoma presenting as a periapical infection.

This case report describes a metastatic bronchogenic deposit involving the lower lip and the adjacent bone in the lower incisor region. The presenting symptoms were very similar to those of a dentoalveolar infection and extraction of the lower incisor teeth failed to provide any relief. Comparison of radiographs taken 6 months earlier suggested that the metastatic deposit very probably spread from the lower labial sulcus into a site of periapical infection, involving the lower incisors and the adjacent bone.