Subject(s)
Dental Amalgam , Retrograde Obturation , Dental Bonding , Dental Cavity Lining , Dental Leakage/etiology , Electrochemistry , Humans , ZincABSTRACT
Apical leakage was analyzed quantitatively in extracted teeth with varied levels of remaining gutta-percha. The effect of the method of gutta-percha removal on the apical seal was also evaluated. Ninety teeth were prepared so that 30 teeth had 3 mm of gutta-percha, 30 teeth had 5 mm, and 30 teeth had 7 mm. An additional 75 teeth were divided into three groups of 25 each. A different method of gutta-percha removal was used for each group: hot instrument, mechanical rotary instrument, and chemical solvent. An electrochemical method was used to analyze apical microleakage. Measurements of leakage of each sample were obtained at 24-hour intervals for 30 days. The data suggest that the mechanical method is the most desirable for gutta-percha removal in post preparation. As the level of gutta-percha increased to 7 mm the degree of leakage decreased. At least 5 mm of gutta-percha is necessary for an adequate apical seal.
Subject(s)
Crowns , Dental Leakage/etiology , Gutta-Percha , Post and Core Technique , Root Canal Therapy/methods , Dental Bonding , Electrochemistry , Evaluation Studies as Topic , HumansSubject(s)
Bismuth/administration & dosage , Dental Pulp Cavity/microbiology , Gutta-Percha/administration & dosage , Resins, Synthetic/administration & dosage , Root Canal Filling Materials/administration & dosage , Streptococcus sanguis/physiology , Zinc Oxide/administration & dosage , Zinc/administration & dosage , Animals , Bismuth/pharmacology , Cats , Gutta-Percha/pharmacology , Resins, Synthetic/pharmacology , Root Canal Filling Materials/pharmacology , Root Canal Therapy , Streptococcus sanguis/drug effects , Zinc Oxide/pharmacologyABSTRACT
A new method for assessment of leakage and marginal penetration was developed. The new electrochemical technique employs zero resistance ammetry, and rapid quantitative results can be obtained over a long period of time. The purpose of the study was to compare the reliability of this method of assessment of leakage versus the autoradiographic and dye penetration techniques. The electrochemical data showed that there is a very sharp increase in the penetration during the first 10 days and that maximum leakage occurred on days 11 to 14 of immersion, after which electric flow remained constant. The correlation of the electric readings with the evaluations obtained with the dye penetration and autoradiographic technique was r = 0.46 and r = 0.52, respectively. The correlation was especially correct at the two extreme ends of the electric score ranges.
Subject(s)
Dental Bonding/standards , Autoradiography , Coloring Agents , Electrochemistry , Humans , Radioisotopes , Time FactorsABSTRACT
The tissue fluid content of instrumented but unfilled root canals of five cats were analyzed for possible localization and growth of intravenously injected bacteria. Although it was possible to maintain a bacteremia for at least 120 minutes, the results showed that the test organisms were not capable of being attracted in the stagnant tissue fluid of the unfilled root canals. Even 48 hours after injection, all samples obtained from the canals were negative for the test organism. The phenomenon of "anachoresis" in unfilled root canals could not be documented under the experimental design.
