Die ossäre Metastase im Oberkiefer als Erstmanifestation eines Nierenzellkarzinoms

Background

Bone metastases in the upper jaw are relatively rare but not unusual in oral and maxillofacial surgery. In many cases finding the primary tumour is difficult because of its occult location.

Case report

We describe a 53-year-old female patient who suffered from a tumor in the oral cavity. The first histological and clinical diagnosis revealed a granuloma pyogenicum. Because of the delayed healing process another biopsy became necessary showing a metastasis of an unknown primary tumor. Diagnostic procedures detected an adenocarcinoma of the left kidney with pelvic metastases. Appropriate surgical intervention and chemotherapy were subsequently initiated.

Conclusion

The present case report demonstrates how difficult it can be to provide the right pathological diagnosis in biopsy material even regarding obvious malignancy. Therefore thorough diagnostic efforts are indispensable to facilitate the causal treatment of an unknown primary tumor.     

Color stability and hardness in dental composites after accelerated aging.

OBJECTIVES: To investigate the color and microhardness changes of five chemically- and five light-curing composites as a function of accelerated aging from light exposure. MATERIALS AND METHODS: From each material five composite specimens were embedded in epoxy resin prior to determining the Knoop microhardness of the surface. For analyzing the color DeltaE*=f((L*a*b*)) with a spectrophotometer, three discs per composite were prepared. After measuring the baseline for hardness and color the same specimens were exposed to a xenon arc light and water in a Weather-Ometer machine for a total radiant energy of 150 kJ/m2 and 122 h. The microhardness and the color were again determined following the aging treatment. RESULTS: Each material showed a significant increase in hardness after aging treatment (p<0.05). Comparing the hardness changes (in %) of the light-cured materials with the chemically cured materials, no significant difference could be found. Perceptible color differences could be observed for all the materials. Three brands showed small differences with DeltaE*=1.6-2.2, while four composites had DeltaE* ranging from 6.2 to 15.5. A significant correlation between hardness values and color changes could not be established. CLINICAL SIGNIFICANCE: The findings suggest that, since light-curable materials showed significantly more resistance to color changes after accelerated aging by light and water than chemically-cured materials, they may be more esthetically acceptable. Color changes were not correlated with surface hardness changes of the materials after aging.     

Comparison of preoperative pain and medication use in emergency patients presenting with irreversible pulpitis or teeth with necrotic pulps

OBJECTIVE: This retrospective study compared differences in preoperative pain and medication use in patients with moderate to severe pain who sought emergency endodontic care for teeth with irreversible pulpitis and for symptomatic teeth with necrotic pulps. STUDY DESIGN: A total of 323 patients seeking emergency endodontic treatment completed questionnaires regarding their biographical information, pain, pain history, and medications. Teeth were tested for vitality, mobility, percussion, and palpation pain. Lymphadenopathy was also evaluated. RESULTS: Patients with irreversible pulpitis waited significantly (P <.05) longer before seeking emergency care (9 days vs 4 days) than patients with symptomatic teeth with necrotic pulps. No differences (P >.05) were found between the groups in terms of analgesic or antibiotic use and pain relief from preoperative narcotic medications. Nonnarcotic analgesics were reported to significantly reduce pain more often in patients with symptomatic teeth with necrotic pulps. There were sex differences in the group of patients with irreversible pulpitis: More women than men were taking analgesic medications and, in the group having symptomatic teeth with necrotic pulps, more men than women reported pain relief from their analgesic medications. CONCLUSION: Patients with irreversible pulpitis wait longer to seek emergency treatment. A majority (81%-83%) of emergency patients with moderate to severe pain will have taken some type of medication(s) to help control their pain, and more women than men with irreversible pulpitis will take an analgesic. By taking their preoperative medication(s), this group of patients will get relief 62% to 65% of the time; furthermore, more men than women with symptomatic teeth with necrotic pulps will experience pain relief.     

Integrating oxalate desensitizers with total-etch two-step adhesive

Compromised bonding of total-etch adhesives to dentin treated with oxalate desensitizers results from the interference of a surface layer of acid-resistant crystals of calcium oxalate. We hypothesize that effective tubular occlusion and dentin bonding may be simultaneously achieved by depleting dentin surfaces of calcium with acids before desensitizer application. Dentin specimens treated with 4 oxalate desensitizers before or after being acid-etched were bonded with a two-step adhesive. Microtensile bond strengths ( micro TBS) were significantly lower, compared with the control, when oxalates were used before the specimens were acid-etched; in contrast, when oxalates were used after acid-etching. micro TBS were similar to nonoxalate-treated controls. Dentin surfaces and tubular orifices were covered with a surface layer of crystals when desensitizers were applied to fractured dentin and smear-layer-covered dentin before specimens were acid-etched. However, when the dentin was acid-etched prior to the application of oxalate desensitizers, the crystals were largely limited to the subsurface of dentinal tubules, where they did not interfere with subsequent resin bonding.     

Problem-based learning: effects on standard outcomes

Dental students at the Harvard School of Dental Medicine (HSDM) participate fully in the first two years of the curriculum with the Harvard Medical School (HMS) while also taking parallel dental classes. HSDM students were first exposed to problem-based learning (PBL) in 1987 when the "New Pathway" curriculum was introduced at HMS in the first two years of the medical school curriculum (the HSDM courses remained traditional lecture-based classes). In 1994, HSDM incorporated PBL into the first, second, and third (clinical year) year dental courses, and the curriculum shifted from a five-year curriculum to a four-year curriculum. The purpose of this study was to evaluate the effect of PBL and program length on measurable outcomes for dental education: NBDE Part I scores, attrition and graduation rates, and percentage of graduates entering postdoctoral training programs. This study was designed as a retrospective analysis of outcomes data from 1980 to 2002. Univariate linear regressions were computed for each measure against each outcome. Subsequent bivariate regression analyses revealed that the implementation of PBL has markedly affected NBDE Part I scores, graduation rates, attrition rates, entrance into postdoctoral plans, and percentage of graduates entering GPR/AEGD programs, while program length has had an effect on graduation rates, attrition rates, entrance into postdoctoral programs, and percentage of graduates entering GPR/AEGD programs. The findings of this report suggest that the implementation of PBL combined with a change in program length has been successful for all outcomes measured and that PBL alone has contributed to the rise in NBDE Part I scores among HSDM graduates.     

Relative levels of mRNA encoding enamel proteins in enamel organ epithelia and odontoblasts

Amelogenin, enamelin, sheathlin (ameloblastin/ amelin), enamelysin (MMP-20), and KLK4 (EMSP-1) are the major structural proteins and proteinases in developing tooth enamel. Recently, odontoblasts were reported to express amelogenin, the most abundant enamel protein. In this study, we hypothesized that odontoblasts express all enamel proteins and proteases, and we measured their relative mRNA levels in enamel organ epithelia and odontoblasts associated with porcine secretory- and maturation-stage enamel by RT-PCR, using a LightCycler instrument. The results showed that amelogenin mRNA in secretory-stage EOE is 320-fold higher than in odontoblasts beneath secretory-stage enamel, and over 20,000-fold higher than in odontoblasts under maturation-stage enamel. Similar results were obtained for enamelin and sheathlin. Enamelysin mRNA levels were equivalent in these two tissues, while KLK4 mRNA was higher in odontoblasts than in secretory-stage EOE. These results support the conclusion that odontoblasts are involved in the formation of the enamel layer adjacent to enamel-dentin junction.     

Decontamination of tried-in orthodontic molar bands

Molar bands are commonly used to retain orthodontic attachments on posterior teeth and due to the variation in the size of such teeth, it is usually necessary to 'try in' several bands before the correct one is selected. A possible concern with re-using such bands is the lack of cross-infection control, even following autoclaving, due to the presence of one or more small bore lumen (the archwire and headgear tubes). The aim of this experiment was, therefore, to determine whether such bands could be successfully decontaminated so that they could be re-used without a cross-infection risk. Two hundred orthodontic molar bands that had previously been tried in patients' mouths, but not cemented into place, were tested. Each band was decontaminated using an enzymatic cleaner/disinfectant and then sterilized using either a downward displacement (n = 100) or a vacuum cycle autoclave (n = 100). Following autoclaving each band was inoculated into brain heart infusion culture broth and incubated at 37 degrees C for 5 days. None of the decontaminated bands exhibited growth after 5 days. It would appear that, using this methodology, there is little risk of a cross-infection hazard occurring with the re-use of previously tried-in and decontaminated molar bands.     

Biocompatibility of resin-based materials used as pulp-capping agents

AIM: To evaluate and compare the response of pulps of rats capped with resin-modified glass-ionomer cement (RMGIC) or self-etching adhesive system. METHODOLOGY: Class I cavities were prepared on the occlusal surface of 54 maxillary first molars of 27 rats. Pulp exposure was performed on the cavity floor. The following resin-based materials were applied as pulp-capping agents: G1, Clearfil Liner Bond 2V (CLB 2V; Kuraray Co., Japan); G2, Vitrebond (VIT; 3M/ESPE, USA). In group 3 (control group), a calcium hydroxide/saline paste (CH; Labsynth, Brazil) was used. The cavities were restored with amalgam. After 7, 30 and 60 days, the animals were sacrificed and the jaws were processed for microscopic evaluation. RESULTS: Despite the inflammatory response caused by the experimental and the control materials at 7 days, pulpal healing associated with calcified barrier formation was observed at 60 days following the pulp therapy. Both resin-based materials promoted a large zone of cell-rich fibrodentine matrix deposition on the pulp horn related to the pulp exposure site, which was larger to VIT than to CLB 2V specimens. Tertiary dentine underneath the fibrodentine matrix was deposited by a layer of elongated pulpal cells. The remaining pulpal tissue exhibited normal histological characteristics. In the control group, healing and dentine-bridge formation was observed at 30 days. Pulpal breakdown occurred only when bacterial infection occurred. CONCLUSION: Both experimental pulp-capping agents allowed pulpal healing characterized by cell-rich fibrodentine and tertiary dentine deposition as well as calcified barrier formation.