This study demonstrates the effectiveness of a step-by-step carving technique that is quickly and eficiently mastered by dental students. Thirty-six inal-year dental students volunteered to participate in this study. The students were given pre-prepared lower right irst molar simulation teeth that had the occlusal half replaced in carving wax. The study was conducted in three time phases: pre-test (Time 1), participative learning (Time 2), and post-test (Time 3). The pre-test had the students carve the wax with no instruction. Instruction and demonstration of the technique were given at Time 2, and the post-test had the students carve the tooth again with no guidance but with training. A statistically signiicant increase with a nearly medium effect size was found from Time 1 to Time 2. A statistically signiicant increase with a medium effect size was found when comparing Time 2 to Time 3. A statistically signiicant increase with a large effect size was found when comparing Time 1 to Time 3. This technique has proved to be an effective method of simultaneously teaching a large cohort of predoctoral dental students. The technique is consistent with constructivist learning theory.Dr. Kilistoff is Associate Chair, Clinical Affairs, and Clinical Professor, Prior to this study, tooth anatomy (second year) and operative techniques (years 3 and 4) in the predoctoral curriculum at the College of Dentistry, University of Saskatchewan, Canada, were taught in discrete modules, using standard textbooks, and a mix

A Kilistoff Clinical RelevanceThe purpose of this technique is to provide an efficient and easily learned method for carving amalgam and composite restorations. SUMMARYBoth amalgam and composite restorations can quickly and accurately be carved using a systematic technique. By following the outlined steps, anatomically accurate restorations can be easily achieved. Inlay wax is used as a training medium to negate the setting constraints and as a high fidelity simulation.

The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and 4′,6-diamidino-phenylindole-(DAPI)-staining. Extracted human premolars were instrumented up to F2 (ProTaper Gold) under NaCl 0.9% irrigation and incubated with Enterococcus faecalis for 42 days. Subsequently, different ultrasonically agitated IP were applied to the roots: control (no irrigation), 1. NaOCl 3%, EDTA 20%, CHX 2%, 2. NaOCl 3%, EDTA 20%, 3. NaOCl 3%, EDTA 20%, SDF 3.8%, 4. SDF 3.8%, and 5. NaCl 0.9%. One half of the root was investigated fluorescent-microscopically with DAPI. The other half was grinded in a cryogenic mill and the bacterial DNA was quantified with qPCR. The qPCR results showed a statistically significant reduction of bacteria after the application of IP 1, 2, and 3 compared to the control group. While IP 4 lead to a bacterial reduction which was not significant, IP 5 showed no reduction. These data corresponded with DAPI staining. With qPCR a new molecular-biological method for the investigation of the complete root canal system was implemented. The novel IP 3 had an equally good cleansing effect as the already established IP.

The effect of prenatal administration of different doses of cortisone, corticosterone, dexamethasone, triamcinolone and prednisolone on the fetus and its palatal development was studied. All the glucocorticoids, except cortisone, produced cleft palate in the fetuses. Both the total frequency and morphologically different types of cleft palate were related to the dose of the teratogen. Triamcinolone appeared to be more potent than other glucocorticoid in inducing cleft palate. An association was noted between fetal growth inhibition, the dose of the teratogen and the frequency and type of cleft palate.

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