Browsing by Author "El-Kafrawy, Abdel Hady, 1935-"

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    The effects of apical modification on the vitality of replanted permanent monkey teeth
    (1977) Walsh, John Senan, 1951-; Roche, James R., 1924-; El-Kafrawy, Abdel Hady, 1935-; Koerber, Leonard G.; Starkey, Paul E.; Stookey, George K.
    A study was conducted on the effects in a rhesus monkey of increasing the surface area of pulpal tissue available for revascularisation and regeneration of nerves after replantation of permanent teeth. Four teeth were replanted and used for controls, including two with incomplete apical development. Twelve teeth with completed apical development were replanted immediately after apical modification to increase the surface area of exposed pulp. The technique consisted of creating a facial and lingual groove in the apical region and exposing additional pulpal tissue. Radiographs were taken periodically and the replanted teeth were stable during the study period. The monkey was sacrificed after 93 days. The first hypothesis, that the apically modified teeth would sustain a healthy periodontium clinically for a period of ninety days, was disproved. Histological sections of the teeth and their supporting tissues showed varying amounts of root resorption and ankylosis. All of the apically modified teeth showed pulp necrosis, while three of the four control teeth had reestablished blood and vascular supplies and appeared vital. Ingrowth of granulation tissue was seen in the replanted teeth with pulp necrosis including one control tooth which had failed to revascularize. The second hypothesis, that the apically modified teeth would demonstrate significantly more apical revascularisation and nerve regeneration than the control teeth, was also disproved. In conclusion, the apical modification technique as performed to increase the area available for regeneration of nerves and vessels was not a success. As expected, however, immediate replantation of avulsed teeth resulted in reestablishment of periodontal membrane attachments.
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    Effects of cardiac glycosides on the composition of whole-mixed human saliva
    (1978) McDonald, John S., 1947-; Shafer, William G.; Barton, Paul; Bixler, David; El-Kafrawy, Abdel Hady, 1935-; Standish, S. Miles, 1923-2003
    Electrolyte levels were measured in whole-mixed human saliva collected from cardiology out-patients, to investigate any salivary electrolyte changes occurring in such patients after digitalization. Several recent reports have indicated that clinical symptoms of digitalis intoxication were associated with increased saliva concentrations of K+ and/or Ca++. Because salivary glands contain a highly active Na+, K+-ATPase it seemed logical that these and other salivary electrolytes might be predictably affected by the circulating levels of digitalis. Patients receiving digitoxin (Dtxn) had a higher concentration of Salivary K+ and Ca++ (25.8 ± 2.2 and 2.2 ± 0.2 meq/l, respectively), than the controls not receiving cardiac glycosides (20.1 ± 1.4 and 2.0 ± 0.1 meq/1, respectively). A similar pattern was not found for patients receiving digoxin (Dxn), although the mean Ca++ concentration for females in this group was significantly elevated (control: 1.7 ± 0.2; Dxn: 2.4 ± 0.2 meq/1). The mean serum concentration (ng/ml) of Dtxn was 20.3 ± 1. 9; of Dxn, 1.4 ± 0.2. No change was found in P04, and protein concentrations, or in salivary flow rates between control and experimental groups. The results suggest that salivary electrolyte changes occur after digitalization, but that these changes do not adequately reflect the serum level of digitalis in individual patients. This study was supported in part by PHS 80l-RR5312.
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    Effects of kinetic cavity preparation vs. conventional handpiece preparation on the human dental pulp
    (1998) Collins, Julie M.; Sanders, Brian J.; Dean, Jeffrey A.; Zunt, Susan L., 1951-; El-Kafrawy, Abdel Hady, 1935-
    The purpose of this investigation was to compare the histopathologic effects of kinetic cavity preparation to the histopathologic effects of conventional high-speed handpiece preparation on the human dental pulp. The objective was to test the following hypothesis: kinetic cavity preparation results in significantly fewer pulpal effects than does conventional preparation using the high-speed handpiece. Class V cavity preparations were made in 26 teeth of seven patients who required extraction of these teeth for orthodontic purposes. Thirteen teeth were prepared using kinetic cavity preparation, using 27-um aluminum oxide particles at 160 pounds per square inch pressure. Thirteen were prepared using the high-speed handpiece and 330bur. Glass ionomer restorations were placed in all teeth. Extractions were done 10 to 15days after preparation. On teeth with closed apices, the apical one-third of the root was removed. All teeth were placed in 10 percent formalin solution. Teeth were sectioned and selected slides stained with hematoxylin and eosin for histologic evaluation. Microscopic findings indicated that the amount of remaining dentin was of significant thickness to be protective to the pulp. Pulpal responses ranged from no response in 22 specimens to a mild response in 4 specimens. Based on the results of this study, it was concluded that shallow preparation into the dentin does not cause pulpal damage at 10 to 15 days post-preparation, when using either kinetic cavity preparation or high-speed handpiece preparation. The hypothesis that kinetic cavity preparation causes significantly fewer pulpal effects than does conventional preparation with the high-speed handpiece was rejected.
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    Vitamin - Fluoride supplements: effect on dental caries and fluorosis in sub-optimum fluoride areas
    (1975) Hennon, David Kent, 1933-; Roche, James R., 1924-; El-Kafrawy, Abdel Hady, 1935-; Bixler, David; Katz, Simon, 1920-1987; Standish, S. Miles, 1923-2003; Mitchell, David F.
    This study was designed to determine if additional fluoride, ingested as a sodium fluoride - vitamin supplement would provide added protection against dental caries without causing any significant fluorosis. A total of 456 children, one to 14 months of age, residing in cities having 0.6 - 0. 8 ppm F in the water supply were randomly assigned according to age, sex and community to the following groups : Group A, 0. 5 mg F to age 3 then 1. 0 mg thereafter; Group B (control), vitamins throughout the study; and Group C, 0.5 mg F throughout the study. Dental examinations were started at approximately 2 1/2 to 3 years of age and were repeated every six months. A fluorosis examination ended the study after about seven years. When compared according to length of time on product, Group A had a significant reduction in deft and defs of 42.2 and 47.1 percent at 60 months. Group C had a 32.1 and 37.4 percent reduction. When compared by age, Group A had a 37.5 and 44.8 percent reduction in deft and defs at 66 months. Group C had a 34.3 and 40.1 percent reduction for the same period. No significant reductions were observed in permanent teeth. Based on the fluorosis index (Group A - 0.250; Group B - 0.033; and Group C - 0.188) none of the groups had any unacceptable amounts of fluorosis. The results indicate that up to 1.0 mg per day of additional fluoride does not cause objectionable fluorosis and may be ingested safely by children residing in areas containing 0. 6 - 0. 8 ppm F in the water supply. A 0.5 mg F supplement was almost as effective as a 1.0 mg level in providing added protection against dental caries in primary teeth.