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Author: Roach, P. Journal: JOE. Nov 2001; 27 (11) : 657-660 Reviewed by: Kimberly Pham, D.M.D. Purpose: To investigate the efficacy of Ca(OH)2
, Ca(OH)2 points, Ca(OH)2 and camphorated paramonochlorophenol (CMCP), and 1% chlorhexidine
(CHX) gel- to delay contamination of the root canal system after endodontic therapy has been initiated. Materials & Methods:
Results:
Conclusions:
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Author: Siqueira et al. Journal: JOE: 27(11): 673-75, November 2001. Submitted by: Paul Slusarz, D.M.D. Purpose: To evaluate the ability of three materials – a resinous
root canal sealer (Sealer 26) prepared in a thick consistency, a reinforced zinc oxide-eugenol
cement (IRM), and a glass ionomer cement (Fuji IX)
– in preventing bacterial leakage. Materials & Methods:
Results:
Discussion: Of the materials tested in the present study, Sealer 26 was the most effective in preventing bacterial leakage. Sealer 26 is a resinous cement similar to AH26, however it contains calcium hydroxide but not silver. Although it is recommended for use as a root filling material, the findings indicate that Sealer 26 has a potential to be used in retrofillings when it is prepared in a thicker consistency. |
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Author: Abarca AM, et al. Journal: JOE 2001; 27:670-672 Reviewer: Mark Wang, D.M.D. Purpose: To compare thermafil and lateral condensation techniques with regard to apical sealing & extrusion. Material & Methods:
Results:
Table 1. Incidence (%) of apical extrusion between lateral condensation
& Thermalfil technique
0 rating - no sealer or GP at the foramen
Table 2. Mean leakage values of test groups
Conclusion:
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Week of December 10, 2001 |
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Journal: JOE: 27(11): 679-682, November 2001 Author: Chang, YC et al. Prepared by: Lance Isaac, D.M.D. Purpose: The purpose of this study was to examine the effects of cytokines (IL-1 and TGF-b ). Protein synthesis inhibitor (cycloheximide (CD)), and protein kinase C (PKC) inhibitors (H7 and Go6976) on matrix metalloproteinase (MMP) production in human pulp cell cultures. Materials and Methods: Human dental pulp cells were cultured from briefly impacted third molars from 3 healthy patients. The extracted teeth were placed in phosphate-buffered saline supplemented with penicillin, streptomycin and fungizone, on ice. The crowns and coronal third of the roots were cleaned, the teeth sectioned below the CEJ with HS bur and water, the pulp tissue removed aseptically, rinsed in HBSS, minced in Eagle’s medium supplemented with 10% fetal calf serum. Cultures were maintained at 37° C in a humidified atmosphere of 5% CO2 and 95% air. Confluent pulp cells were trypsinized, counted, and plated at a concentration of 5 x 104 cells in 60mm culture dish and allowed to reach confluence. Cells were cultured for 48h, at which time the medium was changed to a medium containing 10% FCS and appropriate concentrations of cytokines, protein synthesis inhibitor, and PKC inhibitors. The conditioned medium samples were collected on days 1, 2, 4, and 8 and stored at –20°C until assayed. Cell extracts were also assayed. Type IV collagenase (gelatinase) activity was assayed by zymography (SDS-PAGE). Results/Discussion: The main gelatinase secreted by human pulp cells migrated at 72kDa and represented MMP-2. Minor gelatinolytic bands were also observed at 92kDa, corresponding to MMP-9. After an 8d culture period, CD>H7>TGF-b >Go6976 were found to depress MMP-2 production. IL-1 was found to elevate MMP-2 production. These cytokines and pharmacological agents had no effect on MMP-9 production or secretion. Overall, it seems that inflammatory cytokines stimulate the production of elevated levels of MMP-2, and MMP-2 might play a role in pulpal inflammation (MMPs are an important group of zinc enzymes responsible for degradation of ECM components such as collagen and proteoglycans). In addition, agents that target protein synthesis or the protein kinase C pathway in human pulp cells inhibit MMP-2 production, and such inhibition may contribute to therapeutic efficacy. |
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Author: Kenan Clinton and Van Himel Journal: JOE: 27(11): 692, November 2001 Reviewer: Alison Morrison, D.M.D. Purpose: To compare a warm gutta-percha obturation technique (Thermafil Plus) with lateral condensation for the ability to canal walls of a root canal system. Materials and Methods: An extracted permanent maxillary central incisor was mounted in clear casting resin. Four alignment holes were drilled to assist in realigning the two halves after each fill. The root and block were sectioned mesiodistally through the center of the root canal. The tooth was instrumented to a visually obtained working length using an orifice shaper and nickel-titanium rotary files. During observation of the instrumentation, depressions and grooves were intentionally placed into the canal walls. The canal was obturated twenty times with each technique. Each case was evaluated and videotaped using the following evaluation criteria:
Results: A statistically significant difference (p< 0.005) was found between both techniques in all categories. Gutta-percha using the Thermafil technique was better able to flow into lateral spaces, had fewer voids, and replicated the surface of the root better. It also resulted in more apical extrusion than did lateral condensation. Discussion: The success of any technique depends on the clinician’s
knowledge of the technique, clinical skills, and ability to follow the
manufacturer’s instructions. No technique alone should be judged as the cause
of treatment failure. The results found that none of the Thermafil
samples were short and that both techniques often resulted in apical
extrusion which led the author to the question: Which (being long or being
short in your fill) is more likely to contribute to long-term failure, benign
materials such as sealer and gutta-percha out the canal or a small portion of
the apical canal without material or possibly only sealer?
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Journal: JOE vol. 27, No. 11 November 2001 Author: Gorduysus, M. O. Prepared By: Greg Dearing, D.M.D. Purpose: Utilizing maxillary molars (1) Compare the ability of endodontists to locate and negotiate MB-2 canals in maxillary molars w/o magnification and w/ the operating microscope. (2) characterize the MB-2 canal with regard to prevelance, location, pathway and negotiability Methods and Materials:
Results:
Conclusion:
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Week of Deember 17, 2001 |
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Title: Obturation of a retained primary mandibular second molar using mineral trioxide aggregate: A case report Authors: O’Sullivan, S. M. and et. al. Journal: JOE, vol. 27(11), November 2001, pg 703-705 Reviewed by: Andy Schoelch, DSS Purpose: To present and follow a case using an alternate method of root canal obturation using MTA Case Report:
Conclusion: This technique seemed to provide a biocompatible seal of the root canal system
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Authors: Parsons, J.R. and et. al. Journal: Journal of Endodontics, 27 (11):699, November 2001 Reviewed by: Donna Salin, D.M.D. Purpose: To evaluate, longitudinally, coronal discoloration from four sealers. Materials and Methods:
Results: Discoloration was induced by all four sealers, with slight to moderate visible changes that increased progressively through the 12 months. For all groups, the discoloration was most evident in the cervical third of the crown and on the cervical root surface with minimal to no changes in the occlusal third. There was slightly more discoloration with AH26 and Kerr Pulp Canal Sealer. Discussion: Predictably, AH26 and Kerr Pulp Canal Sealer caused slightly more discoloration (these are silver-containing sealers in which the silver corrodes to a gray-black, contributing to the staining). The other two sealers tested did not contain silver; however, contain chemical ingredients, such as eugenol, that will oxidize and darken with time, leading to dentin staining. In this study, no effort was made to remove the bulk of sealer placed in
the pulp chamber. In a clinical situation every effort should be taken
to remove as much of the sealer as possible.
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Author: Lambrianidis, T. et al Journal: JOE 27(11)696-698 Reviewed by: M. Pallante, D.M.D. Purpose: In vitro study to evaluate the roles of the apical constriction and foramen and the use of a patency file on the apical extrusion of NaOCl and debris. Materials and Methods: Thirty-three freshly extracted human, single rooted maxillary incisors were used. Visual examination ensured the existence of a completely formed apex and straight roots. Teeth were stored at room temp. in 10% buffered formalin phosphate. Access cavities were prepared and a #10 hedstrom file was extended beyond the apical foramen to ensure patency. Teeth were mounted in holes in preweighed bottles and sealed with sticky wax. Irrigation solution used was 1% NaOCl. Teeth were instrumented using a step-back technique to a #30 file to the apical constriction and a size 70 was 3.5 mm short of the working length. A patency file was not used deliberately throughout the root canal preparation. Irrigation was performed every second instrument by placing the needle tip 3 mm short of working length. A total of 10 ml NaOCl was used per tooth. Extruded NaOCl and debris was weighed. Teeth were then held while the apical constriction was deliberately enlarged with a #30 file protruding 3 mm apically. Again, teeth were mounted in the bottles and a #55 file was worked to 1.5 mm short of working length to create a ledge. A #90 file was used coronally to the enlarged apical constriction. No patency filed was used and irrigation was identical to the first experiment. Extruded NaOCl and debris were weighed and the results were subjected to statistical analysis using the Student’s t test. Results: Mean weight of apical extruded debris was .404 g for instrumentation when the apical constriction was intact and .015 g when it was deliberately enlarged. Discussion: In this study, the amount of NaOCl and debris was measured because they are both responsible for periapical inflammation and post-operative pain. There was a significant difference in the amounts of extruded material before and after enlargement of the apical constriction, with greater extrusion when it remained intact. While this data appears paradoxical, the authors report that it may be due to the apical plug formation. This would be in accordance with Myers 1981 study that shows the least amount of extruded debris in teeth instrumented 1 mm short of the foramen as opposed to instrumenting to the foramen. The literature shows no consensus on the consequences of apical plugging with autogenous dentin. When dentin chips are free of microorganisms, satisfactory healing has been observed. However, when they are contaminated, we see discouraging results. The authors are careful to note that while in all the in vitro
studies, like this one, a measurable amount of extruded debris was
consistently observed, however in the only in vivo study performed, this
was not the case due to the fact that periapical tissue serves as a natural barrier preventing
extrusion.
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