Biomedical subjects
B G Seto
Publications and source records attributed to B G Seto.
Absence of radiometric differentiation between periapical cysts and granulomas.
A recent study reported that the mean density of periapical cysts was greater than that of periapical granulomas. This study, which used a larger sample size and a robust method for standardization of density and contrast between images, found no difference between the radiographic density of cysts and granulomas classified by microscopic evaluation. Cysts tend to be larger than granulomas, but there was wide variation in size of both types of lesions. There was no significant correlation between the density of a lesion and its size.
Evaluation of ultrasonic and sonic instruments for intraradicular post removal.
Ultrasonic instruments are a valuable asset for removing intraradicular posts from root canals before nonsurgical endodontic therapy. The purpose of this study was to evaluate the relative efficacy of post removal by ultrasonic and sonic devices. Fifty extracted teeth were instrumented and obturated. The canals were prepared and Parapost #5 posts were cemented with zinc phosphate cement. The teeth were divided into five groups, subjected to ultrasonic or sonic instrumentation and the time measured until post removal. Median values in minutes for the post extractions in each group were: Cavitron = 6.0, Enac = 8.3, and Neosonic = 41.2. Sonic instruments were generally unable to remove the posts. The results of this experiment indicate that the Cavitron and Enac ultrasonic units are significantly more efficient for removing posts than the Neosonic. Sonic instruments were not useful for post removal.
Torsional properties of twisted and machined endodontic files.
The torsional properties of conventionally twisted K-type endodontic files and recently developed machined K-type endodontic files were compared. File sizes 10 through 40 were subjected to torsional load in clockwise and counterclockwise directions independently. Results showed that a statistically significant reduction in clockwise rotation occurred at failure with all of the machined files except size 10. Counterclockwise rotation at failure was also significantly lower for the machined files in sizes 10 through 30. There was no difference in torsional strength between the file types regardless of rotation direction. Therefore, machined files exhibit less ductility than twisted files prior to fracture and may be more susceptible to torsional failure clinically.
Bond strength of etched-metal resin-bonded cingulum rest seats.
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Photoelastic analysis of stresses in resin-bonded cingulum rest seats.
Two-dimensional photoelastic analysis of resin-bonded cingulum rest seats demonstrated improvement in stress distribution when the lingual surface of the tooth was prepared with a cingulum groove. This preparation is more important for teeth that are more vertically or lingually oriented and have flatter lingual surfaces, such as mandibular canines.
Chronic osteomyelitis of mandible caused by penicillin-resistant Bacteroides ruminicola. Report of a case.
Osteomyelitis of the jaws caused by a Bacteroides species is uncommon. A case of osteomyelitis of the mandible caused by penicillin-resistant Bacteroides ruminicola is reported. The diagnosis was confirmed by isolation of the organism and bone scan (99mTc medronate disodium) of the mandible. Clindamycin and hyperbaric oxygen therapy resolved the infection.
Oral mucositis in patients undergoing bone marrow transplantation.
Thirty patients who received bone marrow transplantation treatment from HLA identical sibling donors for immunologic and malignant diseases were studied. In essentially all of the patients oral changes developed during the first 30 days following transplant. Oral symptoms frequently constituted the major complaints of the patients during the follow-up period. The oral changes included mucositis, xerostomia, pain, and bleeding. Mucositis was more severe and of longer duration when associated with herpes simplex infections and when optimal oral hygiene was not maintained. Xerostomia which accompanies engraftment was an early sign of acute graft-versus-host disease. A nonbrushing method of oral hygiene was effective in reducing the severity and duration of mucositis. This technique offers a short-term alternative to brushing in pancytopenic patients who are susceptible to bleeding or trauma.
Analysis of endodontic therapy in patients irradiated for head and neck cancer.
The outcome of endodontic therapy in 16 patients irradiated for head and neck cancer was studied. Thirty-five postradiation endodontically treated teeth (54 roots) were included in the study. The follow-up period ranged from 6 months to 54 months. At the time of last follow-up, 46 of 54 roots were being maintained. No osteoradionecroses were seen in association with teeth that had been endodontically treated. From this review, it is clear that endodontic therapy is a viable method of treating diseased teeth in patients irradiated for oral neoplasms.
Resin bonded etched cast cingulum rest retainers for removable partial dentures.
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Dental management of acute leukemia.
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Safety of hospital dental treatment for the high-risk patient.
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Invasive Candida albicans infections of the oral cavity in immunocompromised patients.
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Comparison of the plaque-removing efficacy of four nonbrushing oral hygiene devices.
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Mechanism of systemic allergy: report of a case involving an aluminum chloride solution.
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