Biomedical subjects
Publications and source records attributed to J C Donnelly.
Pheochromocytomas are rare catecholamine-secreting tumors with a 2-4% maternal morbidity rate and a fetal loss rate of 11%. Sickle cell disease is also associated with increased maternal and fetal mortality. We report the first case of a primigravid woman with both conditions and a successful pregnancy outcome.
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A case report of treatment for a traumatically intruded maxillary central incisor is described. An attempt at accelerating eruption via surgical exposure of the embedded tooth was only partially successful. Orthodontic extrusion of the partially erupted tooth brought the tooth into correct position.
A study was conducted to evaluate coronal microleakage of Super EBA and Ketac-Endo when used as sealers with single-cone gutta-percha (GP) root canal obturation. The root canals of 24 extracted human teeth were instrumented with flared preparations to a minimum #40 master apical file size. Ten teeth were obturated with a single GP cone and Super EBA as the sealer and ten teeth were obturated with a single GP cone and Ketac-Endo as the sealer. Four teeth were used as controls. Salivary bacterial microleakage studies were conducted to determine whether these sealers could prevent coronal microleakage through the root canal in the absence of a coronal tooth restoration. There was no bacterial penetration through the apical foramen for either sealer tested during the 60-day test period.
Thirty extracted human single-root teeth were instrumented to #45 file size while creating a continuous coronal taper. Canals were obturated with Roth 801 sealer and either JS Quick-Fill or lateral condensation of gutta-percha. Mean apical linear microleakage of India Ink was evaluated in cleared teeth using a stereomicroscope. Significantly less leakage (p < 0.1) occurred with lateral condensation than with JS Quick-Fill.
Dental emergencies have been well documented and evaluated. The results of dental emergencies have been lost duty time, decreased unit effectiveness, disruption of routine care, and hindrance to the military mission. The potential of dental emergencies to reduce combat effectiveness is still a major concern. The current U.S. Army and Department of Defense (DOD) military personnel dental classification system, as regulated by DOD Instruction 6410.1, places certain patients broadly into the potential emergency, class 3 category. Changes are needed to make this system more effective and predictive. In addition to various acute conditions, more emphasis should be focused on caries- and surgery-related problems to identify the majority of individuals at high risk for emergencies. Based on an extensive literature review, changes in the current system of classification are proposed.
Dentatus stainless steel dowels were cemented 5 mm into prepared canals of extracted human teeth with C&B Metabond cement. One half the dowels were lubricated before cementation to ensure easy subsequent retrieval. Significantly less tensile force was required to dislodge the lubricated dowels (p = 0.0209). Retrievable lubricated dowels could provide dentists the option of nonsurgical endodontic retreatment in lieu of endodontic surgery. However, lubrication cannot be recommended for clinical use at this time because of the potential for the dowel to unscrew during normal oral function. Further studies are required to determine the effects of rotational forces on the lubricated dowel, surface design of the dowel on retention, and chemical interaction of the lubricant on the resinous cement. Long-term effects of the lubricant on the cement are unknown.
Forty-six extracted human teeth, 26 maxillary central incisors, and 20 mandibular incisors were instrumented with flared preparations. The maxillary and mandibular incisors were prepared to #50 and #30 master apical file sizes, respectively. Ten maxillary and mandibular teeth were obturated with a single gutta-percha (GP) cone and Super-EBA cement. Ten maxillary and mandibular incisors were obturated with laterally condensed GP and Roth 801 sealer. Six maxillary incisors were used as controls. Apical leakage of India ink was measured using a stereomicroscope after clearing the teeth. Results showed significantly less leakage in the mandibular incisors filled with GP and Super-EBA (p<0.05). There was no significant difference in leakage when comparing the maxillary central incisors (p>0.05). In this in vitro study, root canal obturation with a single GP cone and Super-EBA showed promise as an effective way to eliminate or reduce apical microleakage. Further studies are needed to test the ability to use this obturation method clinically.
This study describes two tests of the in vitro accuracy of several models of electronic canal length measuring devices (ECLMDs) using a gelatin test model and extracted human teeth with fully formed apices. In part 1, four previously untested ECLMDs were used in dry canals after access and pulpectomy. File lengths with wth file tip just visible at the foramen were compared to ECLMD lengths. Clinically significant ECLMD measurements of > or + 0.5 mm than visual length were noted with two ECLMDs 16.6% and 10% of the time. The other two ECLMDs had no measurements >0.5 mm than the visual measurement. The gelatin test model proved highly accurate with 4 of 6 ECLMDs tested thus far. Part 2 compared the accuracy of a previously tested ECLMD using the gelatin model when taking length measurements with canals both dry and wet with distilled water in them. There was no difference between measurements in wet or dry canals. Irrigation with distilled water may be a clinical aid when using resistance ECLMDs.
Forty-five extracted human molar teeth with curved facial or mesial canals were instrumented to a #45 file with three different file types using balanced-force (BF) instrumentation. Pre- and postoperative X-rays were taken, projected, and file location traced to determine the canal curvature according to the method of Schneider. Results showed statistically less reduction in canal curvature with nickel-titanium (NT) files compared with either Flex-R (FR) (p < 0.05) or K-Flex (KF) files (p < 0.0021). There was no significant difference comparing FR with KF files (p > 0.05). Under the conditions of this study, NT files used with the BF technique were significantly less likely to change canal curvature than either FR or KF files when instrumenting curved root canals.
Threaded dowels were cemented into prepared canals of extracted human teeth by use of unfilled Bis-GMA resin cement. One half the dowels were lubricated before cementation, unscrewed partially, and reseated to original length after cement had set, to assure retrievability. There was no significant difference in mean tensile force required to dislodge the dowels cemented with or without prior lubrication. Lubrication of dowels makes them predictably and easily retrievable with no short-term effect on tensile strength of the cemented lubricated dowels. Long-term effects of the lubricant on the resin are unknown.
This article describes an in vitro test of the accuracy of a model for demonstrating the operation of electronic canal length measuring devices (ECLMDs). The model is made from commercially available gelatin which is mixed with sterile saline solution. Extracted human canine and anterior teeth with fully formed apices had access preparations and complete pulpectomies before drying the canals with paper points. The tooth length was determined with an Exact-A-Pex using the gelatin test model. When the apex locator green light-emitting diode indicated 1.5 mm from the apex, the file length to the nearest 0.5 mm was measured with a rubber stop. This length was compared with the length determined by visualization of the tip of a #10 K-Flex file at the foramen. This method was repeated with the Foramatron IV using the instrument's digital reading of zero as the apex location and root canal length. There was complete agreement as to canal length between electronic root canal measuring devices and visual observations. This indicates that the gelatin test model is an accurate in vitro method of determining canal length.
This article describes using a 1-ml syringe as an alternative to a dappen dish to hold chloroform during the chloroform dip root canal filling technique. The syringe effectively holds chloroform while limiting its exposure to the endodontic operatory air.
This article describes how to construct and use a simplified model to demonstrate the operation of electronic root canal measuring devices. The model is effective, more economical than those previously described, and uses readily available materials.
Thirty volunteer subjects were given bilateral injections of one-half carpule of 2% Xylocaine with 1:100,000 epinephrine to anesthetize the incisive nerve. Injections were given either inside or outside the mental foramen. Success (80/80 reading) and duration of anesthesia were verified with the Analytic Technology pulp tester. Pain and preference for either injection type were evaluated via questionnaire. The mental foramen could be located in 1 min 56.6% of the time. There was a significantly greater chance of success for injections given inside the foramen for the second bicuspid (p = 0.0422) and the canine (p = 0.015). There was no statistically significant difference in success for either type injection for the first bicuspid (p = 0.184). There was no significant difference in duration of anesthesia whether given inside or outside the foramen and no difference in pain of injection with either type. Patients had no clear-cut preference for either injection type.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.