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161.
Information and communications technology (ICT) is a universal term describing the use of technology and media to disseminate and share knowledge and information. Educational media provide a means by which information can be communicated between teacher and learner. In this context, the aim of this digest is to summarise and describe the spectrum of tools available. All technologies used in education have their strengths and weaknesses. Variety needs to be balanced by economy. However, it must be remembered that technology is not the overriding issue. The design of the learning environment and the learning experience itself are far more important. Technologies are generally flexible and can be used in a variety of ways. Knowledge of these technologies will help guide appropriate selection. The following tools are described: 1. Telecommunications services; 2. Communications tools (social software) including email, newsgroups, weblogs and wikis; 3. Richmedia in interactive training and learning; 4. Compact discs (CDs) and digital video discs (DVDs); 5. Virtual learning environments (VLE); 6. Sophisticated communications - videoconferencing, webcasting and podcasts; 7. Interactive television; and 8. Virtual reality.  相似文献   
162.
OBJECTIVE: This single blind, crossover design, clinical trial provided a comparative assessment of the oral cleaning of two dental devices as demonstrated through the removal of dental plaque when used according to marketed product-use directions. METHODOLOGY: Twenty-six subjects, both male and female between the ages of 19 and 64 years, completed this two-cell crossover study. Subjects were assessed for whole mouth plaque levels, both before and after use of each of the randomly assigned floss devices, by assessing disclosed plaque using the Modified Turesky Plaque Index. The two floss devices were a Mint Floss Pick and a standard rolled floss. Subjects abstained from brushing the night before appearing in the clinic, and based upon meeting the minimum plaque criteria of 1.5 at the first phase of the crossover, used one of the two floss devices according to the directions for use found on the product packaging. Both pre- and post-device use plaque levels were recorded with calculations made of both the actual difference in plaque level, as well as the percent plaque removed. Data were subjected to an analysis of covariance (ANCOVA), and employed a model consistent with crossover design. RESULTS: Overall results from both phases of the crossover showed the Mint Floss Pick product removed 19.4% of the plaque. The standard rolled floss product removed 15% of the plaque. Both products removed statistically significant plaque when assessed versus pre-treatment levels. Although the ANCOVA identified a statistically significant difference between treatments favoring the Floss Pick product, further statistical examination revealed a significant sequence effect, which led to a conservative product comparison of equivalence. This analysis confirmed that the Floss Pick product was "at least as good as" the standard floss product for plaque removal. Additional analyses of various sites in the mouth, i.e., interproximal, anterior, posterior, etc., also confirmed similarity of performance for both products in this test. CONCLUSION: A two-way crossover assessment of the cleaning capability of a Mint Floss Pick product compared to a standard rolled floss product was performed through assessment of the removal of dental plaque. Results of this clinical investigation support the Floss Pick product to be "at least as good as" standard rolled floss in cleaning capability when both products were used according to their product-use directions.  相似文献   
163.
This study evaluated the fracture loads of three-unit all-ceramic bridges on implants; the core frameworks of the bridges were made of zirconium oxide. Three core framework designs were fabricated according to the design of the bars between the retainers: (i) straight, (ii) curved in the occlusal direction, or (iii) curved in the gingival direction. A static load was applied at the centre of the pontic, and the mean initial crack and final fracture loads were measured and compared. The core framework curved in the occlusal direction had the highest final fracture loads; there were significant differences (P < 0.05) in the mean final fracture load, whereas initial fracture load, which fractured of veneered porcelain, did not show significant differences among three designs. The all-ceramic bridges on the implants made with Procera zirconium core frameworks had high final fracture load. The core framework design that curved in the occlusal direction helped the framework withstand the occlusal load, which results in reliable prostheses, especially in the molar region.  相似文献   
164.
AIM: To compare the ability of two Enterococcus faecalis strains to survive exposure to an irrigation solution containing a high concentration of tetracycline in the root canals of bovine teeth. METHODOLOGY: The root canals of twelve bovine incisor root sections were chemo-mechanically prepared using commercially available drills, sodium hypochlorite and ethylenediamine tetra-acetic acid. The root sections were divided into two groups and inoculated with either a tetracycline sensitive or resistant strain of E. faecalis. The strains are isogenic, however one contains a conjugative transposon related to Tn916 which confers resistance to tetracycline, and the other strain is sensitive to the antibiotic. After 26 days of incubation the root canals were irrigated using one of three solutions (sterile distilled water, 50% ethanol or tetracycline at a concentration of 30 mg mL(-1)). The roots were sampled by grinding dentine and canal contents and the debris collected were incubated in broth to assess growth. RESULTS: Irrigation with sterile distilled water or 50% ethanol did not remove all of the cells present. The tetracycline containing solution was efficient in preventing any growth of sensitive E. faecalis, however the resistant strain was able to survive a 5 min exposure at 30 mg mL(-1). CONCLUSIONS: The presence of the Tn916-like conjugative transposon containing the tetracycline resistance gene tet(M) allowed an E. faecalis strain to survive irrigation using a solution containing an extremely high concentration of tetracycline in a root canal model.  相似文献   
165.
166.
In a randomised, double-blind placebo-controlled single-centre study we compared the efficacy and safety of 0.75% levobupivacaine (without vasoconstrictor) with 2% lignocaine (with adrenaline 1:80,000) and with placebo for postoperative pain relief in 93 patients having day surgery under general anaesthesia for the removal of impacted mandibular third molars. Premedication and preoperative analgesics were not prescribed, although a short-acting opioid analgesic agent was allowed if required during the anaesthetic procedure. Patients were asked to keep a diary card for 2 days after discharge from hospital. The primary endpoint was the number of patients who requested analgesia within 2 h of completion of the operation. In total, 16 (53%) of patients given levobupivacaine requested analgesia compared with 22 (71%) given lignocaine and 23 (72%) given placebo. Patients given levobupivacaine had lower maximum visual analogue pain scores (VAS) and took longer to request rescue medication (P=0.045 compared with lignocaine). Fewer patients after levobupivacaine n=20 (7%) than after lignocaine n=7 (23%) or placebo n=5 (16%) experienced adverse events. Levobupivacaine seems to be a suitable alternative local anaesthetic to lignocaine with adrenaline for pain control after oral operations.  相似文献   
167.
Summary. Objectives. To examine, in relation to changes in national guidance, trends in the provision of general anaesthesia for exodontia in children. Design. Retrospective analysis of hospital records. Setting. University Dental Hospital, Cardiff, UK. Methods. Data were drawn from records of services provided in each of four index months during 1989, 1991, 1997 and 1999 (the years immediately preceding/following the Poswillo Report of 1990 and the General Dental Council's revised guidance of 1998). Results. In the first year after publication of the Poswillo report, there was a 19·6% increase in use of ‘chair case’ general anaesthesia over the four index months. Subsequently, upon the emergence of additional providers, patient flow in 1997 had fallen to 65·8% of that seen at baseline. Following the General Dental Council's revised guidance of 1998, there was a further reduction in the provision of ‘chair case’ general anaesthesia (to 40·8% of that seen at baseline). Conclusions. In this unit, throughput of children receiving general anaesthesia for exodontia has fluctuated in periods marked by changing national guidance. However, it is not possible to attribute such fluctuations in patient flow solely to this factor.  相似文献   
168.
169.
The symptoms of most endocrine system diseases are usually clearly recognizable and most of the times are accompanied by a rich medical history. Many general practitioners are reluctant to treat such cases and prefer to refer these patients to specialists who are trained in management of the medically compromised thus increasing the chances of dental treatment without complications. However, sometimes endocrinal diseases develop slowly and their clinical manifestations are hidden or subclinical in nature. In these cases, neither the patient nor the dentist are aware of the condition and there is the potential of life threatening, emergency situations in what at first seem as simple, straightforward dental procedures. Therefore, the dentist must be able to recognize the clinical problem, differentiate between the different symptoms and initiate the proper management protocol. The most unstable endocrinal disorders that should be treated with great care are diabetes mellitus, mainly hypoglycemia, hyperthyroidism and adrenal insufficiency. The general practitioner dentist can treat patients suffering from these disorders providing the disease is well controlled and balanced and that the dental treatment is not very traumatic.  相似文献   
170.
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