Biomedical subjects
Publications and source records attributed to C J Cunningham.
A unique case of a mandibular molar with 5 canals is described. Literature pertaining to the analysis of the morphology of mandibular first molars is reviewed. Clinicians should thoroughly examine the pulpal floor and radiographs for the possibility of additional canals.
Maintaining the original canal path during instrumentation is a challenge in narrow curved canals. This study compared the maintenance of the original canal path of curved root canals during instrumentation with nickel-titanium (Mac) hand files, nickel-titanium engine-driven files, and stainless steel (K-Flex) files. Canal path maintenance was determined by superimposing instrumentation radiographs over an initial file radiograph and examining for discrepancies. Nickel-titanium hand and engine-driven instruments maintained the original canal path in all cases. The incidence of deviation from the original canal path during instrumentation with stainless steel files increased with file size. The difference between nickel-titanium groups and stainless steel became statistically significant with instruments larger than size 30. In this study, nickel-titanium files were more effective in maintaining the original canal path of curved root canals when the apical preparation was enlarged beyond size 30.
The objective of this study was to compare the bone tissue reactions of Ketac-Fil to the most commonly used retrograde filling material, amalgam, in a rat model. Forty-eight Harlan rats were divided into three groups: amalgam, Ketac-Fil, and controls. Following anesthesia, the right lower incisor was extracted from each animal. A 3-mm long x 1-mm diameter polyethylene tube filled with amalgam or Ketac-Fil was implanted in the extraction site. The animals were killed at 14, 42, and 90 days; and the mandibles were dissected en block and processed histologically. The inflammatory reaction was assessed by the number of plasma cells, lymphocytes, polymorphonuclear neutrophils, giant cells, and osteoclasts within 100 microns of the implant. Bone formation was determined as either present or absent in the same area. There was no statistically significant bone apposition within 100 microns of the Ketac material, and there was a statistically significant increase in inflammation in the amalgam group. This study indicates that both Ketac-Fil and amalgam are relatively biocompatible, and provides support for clinical usage tests of Ketac-Fil as a retrograde filling material.
Thirty-six Sprague-Dawley rats were divided into three groups of 12. Group 1 was a control, whereas group 2 had the dental pulp of the first mandibular molar acutely exposed, and group 3 had dental pulp exposure for 10 days. All animals were injected with 125I-labeled dexamethasone phosphate into the right mandibular vestibule. Each group of 12 was divided into subgroups of 4 and sacrificed at 1, 2, or 4 h. The soft tissue on the buccal side and the mandible with the molars were collected and the radioactivity determined. Dexamethasone was absorbed from the injection site and distributed to the ipsilateral mandible and to the contralateral muscle and bone similarly, regardless of the treatment. Results also indicate a possible osseous affinity for this steroid, which could be beneficial in relieving the pain of intraosseous endodontic flare-ups.
Early recognition and prompt control are the two major factors in dealing with oncologic emergencies. The most common emergencies are tumor lysis syndrome, hypercalcemia, spinal cord compression, and superior vena cava syndrome. Emergencies in cancer can occur at any stage of the disease process or its treatment. It is very important that caregivers are able to recognize and manage these emergencies; serious complications can arise if they are not treated promptly.
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The degree and configuration of canal curvature was studied in the mesial roots of 100 randomly selected mandibular first and second molars. The teeth were radiographed in buccolingual (clinical) and mesiodistal (proximal) directions with #8 K files in place. One hundred percent of the specimens demonstrated curvature in both views. No correlation in degree of curvature was found to exist between the clinical and proximal views. Secondary curvature, in a direction opposite to that of the principle curve, was seen more frequently in the proximal view. In the proximal view, canals exhibited greater mean curvature than in the clinical view 38% of the time. Weine type II morphology (two canals, one foramen) demonstrated the greatest range in canal curvature when viewed from the proximal. Coronal flaring with Canal Master rotary instruments to a level just coronal to the curve significantly reduced the severity of curvatures in both views for most cases.
A clinical case report is presented which describes the sequelae of an iatrogenic lateral crown/root perforation and a formocresol pulpotomy. The post-operative course of the initial therapy included significant hard and soft tissue destruction and eventual tooth loss. The possible implication of the role of formocresol is discussed.
The effects that walking bleach procedures had on root canal filling leakage and the extent of dentinal penetration were studied. Forty teeth were divided into four groups: 1--GP, set sealer, no base; 2--GP, set sealer, 2-mm Cavit base; 3--GP, unset sealer, no base; and 4--GP, unset sealer, 2-mm Cavit base. All were bleached for 7 days, fresh bleach was added for another 7 days, then methylene blue dye was placed for 5 days. The extent of dye penetration apically along the root canal filling and through the dentinal tubules was evaluated. The results indicate that 2 mm of Cavit was sufficient to significantly reduce linear leakage and dentinal penetration. The Cavit should be placed to a level slightly coronal to the facial cementoenamel junction. Teeth with cemental defects demonstrated greater perpendicular dye penetration in the areas of the defects than those with intact cementum. The data from this study suggest the use of a base material over gutta-percha in clinical practice prior to internal walking bleach procedures.
Pain control in endodontics is paramount to patient acceptance of this special area of dental care. Alleviating existing pain is the primary objective of root canal therapy. This paper focuses on the control of pulp and periradicular pain at initial presentation and subsequent to the first visit.
Memory for text that required active construction (generation) on the part of the reader to comprehend some of the information was examined. (Letters were deleted from the words composing some of the idea units of the text). For both high school students and older adults, idea units that had letters deleted were remembered better than idea units with intact words on a cued-recall test. This pattern held for easier as well as for harder letter deletions. It was concluded that retention of textually presented information can be improved in older adults if the presentation format of the text induces or guides mental operations that support good encoding. Production-deficiency accounts and attentional/resource deficiency accounts of age-related text memory decrements are discussed in light of the present results.
A controlled study in patients with bulimia demonstrated a significant benefit from desipramine hydrochloride treatment (91% decrease in binge frequency) in contrast to the results from a placebo (19% increase in frequency). When patients originally taking the placebo crossed over to desipramine therapy, their frequency of binges decreased 84%, so that the overall improvement was 87% fewer binges. Global clinical status improved 3.5 scales, Zung depression scores improved 8.0 points, and a bulimia symptom scale improved 14.7 points. Fifteen (68%) of 22 patients attained complete abstinence from binge eating and purging. The presence or absence of previous episodes of anorexia nervosa did not influence the treatment response. One-month follow-up data indicated persistence of the benefit attained.
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Recent reports have suggested that normal-weight bulimic patients without clinical evidence of major depressive disorder will have an abnormal response to dexamethasone. Of 23 normal-weight bulimic patients without clinical evidence of major depressive disorder, 11 had abnormal results on their dexamethasone suppression tests (DSTs). This finding closely matches those of other reports. After successful treatment with desipramine, repeat DSTs showed conversion to normal suppression in 6 of the 7 patients tested. Pretreatment DST results failed to predict the response to medication. The striking similarity of these findings to those reported in patients with major depression suggests that bulimia may be a consequence or an equivalent of major affective disorder.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.