RS 61 Occurrence of Prevotella intermedia and Prevotella nigrescens in infections of endodontic origin

R~IR.~.1 Using Total Protein Concentration in Pulpal HealingExperimental Periapical Lesions Inflammation Assays. C. RAUSCHENBERGER*, G. R. HOLLAND*, E. PEHOWICH and V. BURGESS C. COOTAUCO, & J. BAILEY, Department of (*Univ. of Michigan, U.S.A. & Univ. of Alberta, Canada) Endodontics, Dental School, UMAB. Baltimore, MD. Following the obturation of root canals in ferret canines with combinations of gutta percha and zinc oxide and eugenol, The detection of regulatory biologic molecules in dentinal fluid may assist our ability to assess the health of pulpal periapical inflammatory lesions persist for at least three months tissue. Yet, procedural difficulties exist in accurately (Holland, Anat Rec 220:318 1988). Using this model a method quantifying the minute amounts of fluid that can be has been developed for measuring the size of periapical lesions clinically collected. Total protein concentrations (TPC) in and applied to the examination of several healing parameters. each sample have been suggested to serve this purpose (i.e. In all 54 ferrets have been used to look at four different healing I L - l / p g protein). However, pulpal inflammation can result in connective tissue degradation and peripheral blood flow factors, time, systemic steroids at low and high dosage and the alterations both of which can affect detectable TPC. The substitution of eugenol free seater. In each group root canal purpose of this study was to relate TPC to clinical and therapy was conducted on the canine teeth under general histological findings in healthy and inflamed pulpal anesthesia and, after a survival or treatment period of 3 or 12 tissues. Healthy tissues were obtained from 7 soft tissue months, the ferrets were again anesthetized and perfused with impacted third molars. Inflamed samples were obtained from 19 carious molars clinically diagnosed with an fixative. In each group some control animals did not receive the irreversible pulpitis and no periapical pathology. Coronal healing regimen. Serial histological sections of the canine root pulp tissue samples were removed from the teeth with and supporting bone were cut and stained with hematoxylin and special attention in the inflamed sample group to include eosin. Using a camera lucida the profiles of periapical tissue immediately subjacent to the caries. One-half of the inflammatory lesions were traced into a small computer and pulp tissue was used to determine TPC b y ELISA (Pierce assembled into 3D reconstructions whose volumes were Chemical Co, Rockford, IL) and the remainder was histologically analyzed. One clinically healthy sample was measured. Allowing a year rather than three months for the confirmed to be histologically necrotic, and one clinically lesions to heal resulted in an average reduction in lesion size inflamed sample was confirmed to be histologically normal. of 28%. Modest dosage of systemic steroid reduced the ANOVA revealed no significant differences in total average lesion size by 62 % but this was only improved to 70% protein concentrations between the healthy and inflamed by increasing the dosage by 2.5 times. Substituting a nonsamples classified clinically or histologically ( F c l i n = 0.269, p>0.05; Fhist = 3.035, 0>0.05). These result~ suz~est ~Fha,l; eugenol containing calcium hydroxide based sealer (Sealapex, biologic mol0q0!~s can be r0ported acc0rdin~ to total Kerr Manufacturing, Romulus, MI) reduced average lesion size Prot¢in coneentr(ttions in p01oal tissue8 irrest)ectiv~ of by 94% and eliminated or avoided formation of lesions in 9 of their clinical or histoloaical inflammatory status. This 12 animals. The most effective reduction in experimental research was supported in part by the Research and periapical lesions is achieved by substituting ~ non-euaenol Education Foundation of the American Association of Endodontists. containing sealer. SUPPORTED BY MRC CANADA

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Occurrence of Prevotella intermedia and Prevotella nigrescens in Infections of Endodontic Origin. K.S.Bae*, J.C.Baumgartner, T.R.Shearer, L.L.David. Oregon Health Sciences University, Portland OR Previous studies have shown an association between P intermedia and endodontic infections. Recently, P. intermedia was shown to be comprised of another species now known as P nigrescens. The purpose of this study was to investigate the occurrence of P intermedia and P. nigrescens in endodontic infections. Sodium dodecyl sulfate polyacrylamide gel (12%) electrophoresis (SDS-PAGE) of whole cell protein was used to produce protein proftles (fingerprints) of interspecies variation. The type strains for P. intermedia (ATCC 25611) and P. nigrescens (ATCC 33563) were used as controls. Thirty-six strains of black-pigmented bacteria previously isolated from endodontic infections and identified as P. intermedia were used in this study. The strains were cultivated on Columbia blood (rabbit) agar base supplemented with menadione (10mg/L) and heroin (5rag/L) in an anaerobic atmosphere (85% N2, 5% CO2, and 10% H2). The bacteria were harvested after 48-72 hours and washed twice in phosphate buffered saline (pH 7.0). After centrifugation (1000Xg, I0 rain) to obtain a cell pellet, 200~1 of 1% SDS was added to the pellet and the lysate was shaken continuously for 20 min at room temperature. The supernatant was obtained after centrifugation (10,000Xg, 5 min) and a protein assay was employed for standardization of the amount of protein used for SDS-PAGE. Molecular weights of polypeptide bands in the gels were estimated by comparison with molecular weight standards. Polypeptide bands were used to differentiate P nigrescens from /3. intermedia. Of the 36 endodontic isolates, 23 (64%) strains were P nigrescens and 13 (36%) strains were P intermedia. Foture ~tudies should evaluate these species for their specific association with ~ndo~tonti¢ infection~; 0nd for contributing virulence factors.

RSIRR9 I Penicillin as a Supplement in Resolving the Localized Acute _v_=_z Apical Abscess. AF FOUAD, EM RIVERA*, and RE WALTON. (University of Connecticut, Farmington CT and University of Iowa, Iowa City IA) The purpose of this study was to examine the effect of penicillin supplementation on the reduction of symptoms of the localized acute apical abscess (LAAA) after emergency endodontic treatment. Patients presenting with pulp necrosis and periapical pain and/or localized swelling were considered for the study. Eligible patients did not have signs of spreading infections or fever, were not on antibiotics, were not immunologically compromised, and did not have any systemic contraindication to the use of oral penicillin. 40 consenting adult patients were included. The patients received necessary endodontic emergency treatment and were randomly assigned using a double blind protocol to one of three groups: Group 1 received penicillin VK 500 mg q.i.d, for 1 week; Group 2 received a placebo according to the same regimen; Group 3 received neither. All patients received lbuprofen 600 mg at the emergency visit and then q.i.d, for 3 days. Patients were given post-treatment cards with a visual analog scale to mark their pain and swelling experienced before treatment, and at 6, 12, 24, 48, and 72 hours after treatment. For evaluation, pain experience was divided into: none, mild, moderate, and severe; and swelling was divided into: none, significant reduction, slight decrease, same size as before treatment, and increased. Post-treatment pain, swelling, and an index of pain and swelling rankings were analyzed using a chi-square analysis (p _<0.05). Postoperative cards of 30 patients (10 in each group) (age 21-72) were available for analysis No statistically significant differences between the three groups were found at any time period. It therefore appears that supplemental penicillin does not significantly reduce symptom~ of patients with LAAA after treatment with local measur~ and (In anti-inflammatorv medication.

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