A Comparative Study of Apical Leakage of Endomethasone, Top Seal, and Roeko Seal Sealer Cements
Lucena-Martín, Ferrer-Luque, González-Rodríguez, Robles-Gijón, and Navajas-Rodríguez de Mondelo
In Situ Antimicrobial Effectiveness of Chlorhexidine and Calcium Hydroxide: Gel and Paste Versus Gutta-Percha Points
Barthel, Zimmer, Zilliges, Schiller, Göbel, and Roulet
Apical Leakage of Five Root Canal Sealers After One Year of Storage
Miletić, Ribarić, Karlović, Jukić, Bošnjak, and Anić
Scanning Electron Microscopy Study of the Adhesion of Prevotella nigrescens to the Dentin of Prepared Root Canals
Yang and Bae
A Comparative Study of Apical Leakage of Endomethasone, Top Seal, and Roeko Seal Sealer Cements
C. Lucena-Martín, PhD, DDS, MD, C.M. Ferrer-Luque, PhD, DDS, MD, M.P. González-Rodríguez, DDS, V. Robles-Gijón, PhD, DDS, and J.M. Navajas-Rodríguez de Mondelo, PhD, DDS, MD
A comparison was made of the apical leakage of three sealers. Fifty single-root human teeth were randomly divided into 5 groups (n = 10; 3 experimental and 2 control). The teeth of the positive-control and experimental groups were instrumented with K-type files to size 45. The experimental groups were obturated by laterally-vertically, condensed gutta-percha with Endomethasone, Top Seal, or RSA sealer cements. The positive-control group was nonobturated and the negative-control group was noninstrumented. The root surfaces were then coated with nail varnish (except the apex in the experimental groups) and immersed in black ink (for 1 week at 37°C). The statistical evaluation of the results obtained by clearing and cross-section techniques showed no significant differences between sealers. Leakage, as determined by the clearing technique, was significantly greater than that quantified by cross-section analysis.
In Situ Antimicrobial Effectiveness of Chlorhexidine and Calcium Hydroxide: Gel and Paste Versus Gutta-Percha Points
Claudia R. Barthel, Dr med dent, Stefan Zimmer, PD, Dr med dent, Sascha Zilliges, cand med dent, Reinhold Schiller, Dr med, Ulf B. Göbel, Prof, Dr med, Dr rer nat, and Jean-François Roulet, Prof, Dr med dent
The aim of this study was to determine the antibacterial effectiveness of either chlorhexidine or calcium hydroxide integrated in gutta-percha points compared with chlorhexidine or calcium hydroxide delivered as gel or paste, respectively. A total of 70 initially sterile roots with open accesses were carried for 1 week in the oral cavities of two volunteers. The roots were then removed, and samples were taken from the root canals for microbial analysis. The roots were medicated with calcium hydroxide paste, 5% chlorhexidine gel, or a chlorhexidine- or calcium hydroxide-containing gutta-percha point. The accesses were closed with bonding material, and the roots incubated for 1 week. After removal of the antimicrobial agents, roots were again checked for bacterial growth. One thioglycolate-soaked paper point was then introduced into each canal, and roots were incubated for 1 week more to observe bacterial re-growth. After 1 week of medication, the absolute bacterial count revealed significant differences compared with the controls. However, only the chlorhexidine-gel and the calcium hydroxide paste group showed no microbial colonization in a considerable number of samples after 1 and 2 weeks.
Apical Leakage of Five Root Canal Sealers After One Year of Storage
Ivana Miletić, DDS, PhD, Sonja-Pezelj Ribarić, DDS, PhD, Zoran Karlović, DDS, MS, Silvana Jukić, DDS, MS, Andrija Bošnjak, DDS, MS, and Ivica Anić, DDS, PhD
A fluid transport model study was used to compare the sealing ability of five root canal sealers (AH26, AH Plus, Apexit, Diaket, and Ketac-Endo) on 60 single-rooted teeth after 1 yr of storage. The root canals were prepared with Gates Glidden drills by using a step-back technique before lateral condensation of gutta-percha with the tested sealers. The specimens were stored in saline solution for 1 yr at 37°C. The leakage was measured by the movement of an air bubble in a capillary glass tube connected to the experimental root section. Apexit (0.490 μl) leaked significantly more than AH Plus (0.378 μl) and Ketac-Endo (0.357 μl), whereas AH26 (0.390 μl) and Diaket (0.429 μl) showed no significant difference from either Apexit or from AH Plus and Keto-Endo.
Scanning Electron Microscopy Study of the Adhesion of Prevotella nigrescens to the Dentin of Prepared Root Canals
Sung-Eun Yang, DDS, MSD, and Kwang-Shik Bae, DDS, MSD, PhD
The purpose of this study was to evaluate the effect of the presence or absence of amorphous, irregular smear layers on the adhesion of Prevotella nigrescens, to the dentin of the root canal by using scanning electron microscopy (SEM). Human incisors extracted within 7 days, with no cavities, no fractures, and no evidence of calcification of the canal, were selected. After cutting the crown portion at the CEJ, root canal preparation was undertaken by using a modified crown-down technique with Profile and Gates Glidden drills. Ten milliliters of physiologic saline solution (groups 1 and 4), 10 ml of 3.5% NaOCl (groups 2 and 5), or 10 ml of NaOCl and 10 ml of 0.5M EDTA (groups 3 and 6) were used as irrigation solution while preparing the canal. After vertical sectioning and ethylene oxide gas sterilization, samples (groups 1, 2, and 3) were immersed in brain-heart infusion broth with yeast extract, hemin, and menadione, inoculated with P. nigrescens (ATCC 33563), and incubated for 3 h at 37°C. All samples were prepared for and observed with SEM. The data were analyzed by using t test and one-way ANOVA. Smear layer was observed to cover the entire root canal surface after root canal preparation. Smear layer was removed and the entrances of dentinal tubules opened widely after applying 3.5% NaOCl and 0.5 M EDTA. A significantly greater number of bacteria were found to adhere to those teeth in which a smear layer was present (p < 0.05). Given that the smear layer produced during root canal preparation promoted adhesion and colonization of P. nigrescens to the dentin matrix, it might also increase the likelihood of canal reinfection.