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Sample Abstracts

Oral Research Sample

Real-Time Quantitative PCR and Culture Analyses of Enterococcus Faecalis in Primary and Refractory Endodontic Infections
J.M. Williams*, M. Trope, M. Heffernan, D.C. Shugars, University of North Carolina, Chapel Hill, NC

Enterococcus faecalis is frequently implicated in endodontic treatment failures. Limited genotype-based quantitative data exist on E. faecalis in primary (PI) and refractory infections (RI). This study sought to develop a real-time quantitative PCR (qPCR) assay to measure E.f. and total bacteria loads in RI and PI, compare qPCR and culture in bacterial quantification and detection, and evaluate endodontic treatment effectiveness on E.f.clearance. Duplicate intracanal samples were collected preinstrumentation (S1), postinstrumentation/irrigation (S2) and post-Ca(OH)₂ treatment (S3) from 15 PI and 14 RI, totaling 29 single-rooted teeth. Samples were cultured on selective and nonselective media in aerobic and anaerobic conditions or analyzed by qPCR using ubiquitous and E.f.-specific primers and fluorogenic probes. qPCR detection range was 101–108 copies/DNA. qPCR was more sensitive than culture in detecting E. faecalis and total bacteria at all time points (McNemar, p<0.05). In RI, E.f. detection was greater using qPCR than culture (time-qPCR/culture: S1-42.8%/14.2%, S2-57%/7.1%, S3-50%/0%; Wilcoxon, p<0.05). In PI, E.f. was detected by qPCR/culture in S1-13%/6.7%, S2-20%/0% and S3-20%/0%. E. faecalis comprised 4% (qPCR)-14% (culture) RI median total bacterial levels at S1 versus 0.03%(qPCR)-3.8% (culture) of PI. Treatment reduced median S1-S3 E.f. counts 10-fold by qPCR and culture in RI; in PI, reduction was detected by culture but not qPCR. E. faecalis detection by qPCR was up to 6-fold more sensitive than culture. E. faecalis was found more frequently and comprised a larger proportion of total bacteria in RI than PI. Following endodontic therapy, E. faecalis and total bacteria were detected in both infection types. Supported by UNC Department of Endodontics

Poster Research Sample

The Effect of Intracanal Anti-Inflammatory Medicaments on External Root Resorption of Replanted Dog Teeth After Extended Extraoral Dry Time
H. Chen*, F.B. Teixeira, A.L. Ritter, L. Levin, M. Trope, University of North Carolina, Chapel Hill, NC

The prognosis of replanted teeth depends on several factors, the most important being the length of extraoral dry time. Studies show that after 60 minutes dry time, external root resorption is predicted. Ledermix™, a paste containing triamicinolone (corticosteroids) and demeclocycline (tetracycline), has been shown to inhibit root resorption after extended dry times. However, discoloration occurs due to the tetracycline in Ledermix™. This study aimed to evaluate the individual influence of corticosteroids and tetracycline on external root resorption. 69 premolar roots of 4 beagle dogs were extracted and instrumented with NiTi files. Group 1 (negative control) was immediately replanted after root filling with GP and sealer; Group 2 (positive control) was root filled with GP and sealer, replanted after 60 minutes dry time; In groups 3, 4 and 5, the canals were filled with Ledermix™, Triamicinolone and Demeclocycline respectively, and replanted after 60 minutes dry time. After 4 months, the dogs were sacrificed and the roots examined histologically for type of healing (favorable or poor) and remaining root diameter (scale 0 6). The results showed the groups treated with Ledermix™, Triamicinolone and Demeclocycline had statistically significantly more favorable healing (84.4%; 72.9%; 58.3%) (χ2, p<0.05) and more remaining root structure (5.83; 5.84; 5.27) (ANOVA, p<0.05) than the group filled with GP (positive control) (1.3%; 1.31). There was no significant difference between Ledermix™ group and Triamicinolone group in either healing or remaining root mass. Corticosteroids were as effective as Ledermix™ on root resorption without the potential for tooth discoloration. Funded by the AAE Foundation

Table Clinic Sample

Decoronation: Preventive Treatment For The Complications Of Ankylosis In The Pediatric Patient
K. M. Jabbs*, Albert Einstein Medical Center, Philadelphia, PA

Ankylosis of anterior teeth after trauma is a relatively common occurrence in children. A tooth that is ankylosed and undergoing replacement resorption can be maintained for a time for esthetic purposes. In the growing child, however, it is imperative to recognize and then deal with the secondary problems of infraocclusion and cessation of alveolar development in the maxilla or mandible in the area of the ankylosed tooth. These problems create obvious esthetic disharmony or even disfigurement in the anterior segment that is nearly impossible to correct. Therefore, it is crucial for the clinician to identify ankylosed teeth early on in dentally traumatized children, think prospectively about alveolar ridge preservation and development, and then, take appropriate action. During the formative years when normal development is critical, proper timing and selection of treatment are essential to improve the quality of life and psychological well being of these traumatized patients in the months and years after the trauma. The purpose of this table clinic is to present the procedures, timing and expected outcomes of decoronation with root submergence in the developing child. A case of decoronation in the adolescent will be presented to illustrate the concept. With this knowledge, the clinician will be better able to identify young patients who are candidates for the procedure, render treatment during the window of opportunity before or during the period of rapid adolescent growth, and maximize the potential for preservation and development of the alveolar ridge.