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Biomedical subjects

L Z Koren

Publications and source records attributed to L Z Koren.

10 recordsLinked to original sources
PubMed1988

A detailed analysis of four long-term silver cone root canal fillings.

Because many failures in root canal therapy have been attributed to the use of silver cones as a filling material, it was decided to examine four roots of three teeth, each of which had been successfully treated endodontically with silver cones ranging from 24 to 34 years previously. These roots, which were resected for periodontal reasons, were examined both under the scanning electron microscope and histologically. Examination with the scanning electron microscope revealed that all four cones were moderately to severely corroded. Histologic examination of two teeth disclosed corrosion products along the entire wall and, in one instance, within the dentinal tubules and apical tissue. The corrosion products, however, were most extensive in the cone that appeared to be loose fitting within the canal. The results indicated that corrosion products occurred in all of the teeth examined. Therefore, corrosion may not be the primary factor accounting for failure in teeth endodontically treated with silver cones.

Corrosion↗
PubMed1988

A prospective randomized trial on efficacy of antibiotic prophylaxis in asymptomatic teeth with pulpal necrosis and associated periapical pathosis.

A recent study from a private endodontic practice compared "prophylactic" antibiotic (high-dose, 1-day) regimens of penicillin V and erythromycin (base or stearate) for patients who had asymptomatic teeth with pulpal necrosis and associated periapical radiolucent lesions (PN/PL). A 2.2% flare-up incidence was found, with no statistically significant differences for penicillin (0.0%), base (2.9%), and stearate (3.8%). No hypersensitivity responses occurred, and gastrointestinal side effects were found primarily with the erythromycins (12.4%). To ascertain whether or not similar results would occur with student operators in a dental school clinic population, the current study was undertaken. One-hundred ninety-five patients with quiescent PN/PL were randomly given either penicillin V or erythromycin (base or stearate). A 2.6% flare-up incidence was found, with no statistically significant differences for penicillin (3.1%), base (1.5%), and stearate (3.1%). No hypersensitivity responses occurred, and GI side effects were found primarily with the erythromycins (17.7%). As can be seen, the results were very similar to those of the recent endodontic practice study. Hence, it can be concluded that the results of the previous endodontic practice study were not unique to any one clinician or method. A comparison was also made between the "prophylactic" penicillin group of the current study and the placebo control group of our previous dental school clinic, student operator study (in which the methods, population, and regimen were almost identical to those of the current study). The results showed that the "prophylactic" penicillin group had significant fewer flare-ups and non-flare-up-associated swelling and pain than did the placebo group. In view of these findings and those from studies from the literature in which "prophylactic" antibiotics were not used, it is our opinion that the antibiotic regimens used in the current study should be a component of clinical endodontic therapy for quiescent PN/PL.

Adolescent↗
PubMed1988

A comparative tissue toxicity evaluation of established and newer root canal sealers.

Grossman's sealer, eucapercha, Endo-Fill, CRCS, Sealapex, Hypocal, and sterile saline solution (0.3 ml of each) were injected into specific dorsal subdermal tissue sites of 12 guinea pigs. The animals were killed after 6 days, 15 days, and 80 days (four per time period). Analysis of tissue response showed that, overall, Sealapex and Endo-Fill had less severe inflammatory reactions than any of the other test materials. Grossman's sealer, CRCS, and Hypocal showed principally severe inflammatory responses at both 6 and 15 days, but mild reactions at 80 days. Overall, eucapercha showed less severe inflammatory responses than Grossman's sealer, CRCS, and Hypocal. Diffuse calcification was induced by the three calcium hydroxide preparations (CRCS, Sealapex, and Hypocal). Eucapercha and Endo-Fill had minute local areas of calcification. Both Grossman's sealer and CRCS did not have overall favorable histologic reactions; however, Grossman's sealer and CRCS have been used successfully clinically. Further clinical studies are needed.

Animals↗
PubMed1987

Comparison of diflunisal and an aspirin-codeine combination in the management of patients having one-visit endodontic therapy.

One hundred seventy-nine patients with asymptomatic or mildly symptomatic endodontic disease had single-visit therapy and were given either diflunisal (n = 94) or aspirin with codeine (n = 85) to control posttreatment pain. In this open-label, randomized study, diflunisal was judged superior to the aspirin-codeine combination in all major categories evaluated. Of patients receiving diflunisal, 93.6% needed the medication for only one day. In contrast, 77.7% of patients receiving aspirin with codeine needed the medication for only one day. Almost 64% of patients receiving diflunisal needed only one dose, while 32.9% of patients using aspirin with codeine needed only one dose. Four or more doses were required by 5.3% of patients receiving diflunisal and by 23.5% of patients receiving the aspirin-codeine combination. In patients receiving diflunisal, 20.2% experienced side effects. In contrast, 29.4% of patients receiving aspirin with codeine reported side effects. Thirty-five percent of patients receiving diflunisal rated the analgesic as excellent; 5.3% rated it as fair or poor. In contrast, 12.9% of patients receiving aspirin with codeine rated the analgesic combination as excellent; another 12.9% rated it as fair or poor. Diflunisal was found to be generally effective and well-tolerated, and superior to aspirin with codeine in the management of pain from endodontic treatment.

Adolescent↗
PubMed1985

Prophylactic use of penicillin V in teeth with necrotic pulps and asymptomatic periapical radiolucencies.

As a result of (1) clinical experience with flare-ups occurring in teeth with necrotic pulps and asymptomatic periapical radiolucencies and (2) on apparent reduction to the incidence of such flare-ups by the administration of penicillin V at the first sign of swelling, this study on the prophylactic administration of penicillin V in similar cases was undertaken. The subjects were 100 consecutive clinic patients whose teeth had necrotic pulps and asymptomatic periapical radiolucencies. At the initial visit, all teeth were instrumented completely to the radiographic apex, with 0.5% to 2.54% sodium hypochlorite as the irrigant. Sterile, dry cotton pellets and ZOE restorations were used. Alternate patients were given 250 mg of penicillin V and an identical-appearing placebo with instructions to take two tablets every 6 hours for the first 24 hours, followed by one tablet every 6 hours until all tablets were taken. Pain and swelling were graded by the patients on five-point scales, and flare-ups were scored when either pain and/or swelling necessitated an unscheduled emergency visit. Fifteen patients developed flare-ups, with significantly more flare-ups in the placebo group (p less than 0.05). The findings indicate that, in selected cases, prophylactic penicillin can be used to prevent flare-ups.

Dental Pulp Necrosis↗