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Title: Evaluation of the incidence of transportation after placement and removal of calcium hydroxide Author: Goldberg et al Journal: JOE Vol. 30 No. 9, September 2004 Reviewer: Alex Wang, DDS Purpose: To evaluate the incidence of apical transportation after the placement and removal of Calcium Hydroxide in straight and curved root canals. Materials & Methods: Twenty maxillary central incisors (group A) and 20 mesio-buccal canals from moderately curved roots of mandibular molars (group B) were instrumented and filled with calcium hydroxide using a lentulo spiral. After seven days, calcium hydroxide was removed and post-instrumentation and final radiographs were superimposed to evaluate the incidence of transportation. Results: In group A, no transportation was detected, whereas in group B, 9 of the 20 canals showed apical transportation. This result was statistically significant. Conclusion:
During removal, residual pastes of calcium hydroxide could block the apical
area of the root, affecting the apical patency in
curved canals. This blockage will cause the file to go in a straight
direction, transporting the canal anatomy. |
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Title: Accuracy
of TMC endo III torque-control motor for
nickel-titanium rotary instruments Authors: Ghassan Yared and Gajanan Kulkarni Journal: JOE 2004.
Vol. 30 (9) pp 644-5. Reviewer: Omar Porras, DMD Purpose: To determine the actual torque
corresponding to four torque settings and evaluate the accuracy of these
torque settings on different TCM motors. Material & Methods: Five TMC motors (Sybron Endo) were tested. The actual torque was measured
using a size 50 Orifice Shaper (Tulsa Dental) mounted on a 16:1 reduction handpiece that was connected to a digital torque meter memocouple through a chuck that clamped the file. The
meter was connected to a computer for measurement recording. Torque 1, 2, 3
and 4 were evaluated at 350 RPM. The
results were analyzed using analysis of variance and post –hoc pairwise comparison. Results: For
each torque settings in all the motors tested, the actual torque settings
where significantly higher than the preset and claimed by the manufacturer. Discussion: The usefulness of torque-control motors in reducing
instrument fracture is questionable. The lowest torque available in the TMC
motors (1.2 Ncm) is higher than the reported torque
at fracture for profile .04 No.15 and 25, 0.21 and 0.48 Ncm
respectively. |
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Title: Antibacterial
efficacy of calcium hydroxide and chlorhexidine gluconate irrigants at 37 ° C
and 46 °C Authors: C.
Evanov, et al. Journal: JOE 2004.
Vol. 30 (9) pp 653 Reviewer: Brian
Chang, DDS Purpose: To
determine the effectiveness of antibacterial activity of irrigants
at body temperatures and an elevated temperature against Enterococcus faecalis. Materials and Methods:
Results:
Discussion: The
results demonstrated that heat enhances the anti-microbial action of both the
10% Ca(OH) 2 solution and the .12% Chlorhexidine group. These results indicate possible ways
of increasing anti-microbial activity in irrigation without resorting to more
cytotoxic irrigants. |
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Title: An evidence-based analysis of the antibacterial
effectiveness of intracanal medicaments Authors: Amanda Law and Harold Messer Journal: JOE 2004. Vol.
30 (10) pp 689-94. Reviewer: Omar Porras, DMD Purpose: To analyze the endodontic
literature evaluating the antibacterial effectiveness of intracanal
medicaments. Material & Methods: A four-step method of evidence-based analysis was
applied.
The search addressed only
human studies. The identified articles were examined following
inclusion/exclusion criteria (Table 2). Also the strength of evidence of the
papers was analyzed (e.g. RCTs, systematic reviews
with meta-analysis, prospective studies). Results: Only 5
papers met the most significant criteria for inclusion, which was the
microbiological sampling post-instrumentation (S2), and post-medication (S3)
as well as the pre-instrumentation (S1); all of them evaluating antibacterial
effect of Ca(HO)2. The best evidence available
was low with all studies characterized as prospective pre-test/post-test
experimental trials with no control participants. The combined overall sample
size was 164 teeth. Pre
instrumentation cultures (S1) were positive in almost all the canals. After
instrumentation (S2) 62% were positive and post medication (S3) 27% of the
overall test samples was positive. Of the cultures that were (+) after
instrumentation (S2), 45 % culture remained positive at (S3). No study evaluating other
medicaments met the inclusive criteria. However, the combined antibacterial
effect of chemo-mechanical preparation and paramonochlorophenol
or camphorated phenol medication showed a similar efficacy as IKI with
approx. 30% positive cultures at (S3). Discussion: This paper reinforces the evidence that canals
cannot by sterilized with chemo-mechanical instrumentation only. Calcium hydroxide remains the best
medicament available. In order to ensure successful outcome it is essential
to reduce the bacterial flora to the lowest level possible using Ca(OH) 2 as interappointment
dressing for at least 7 days before obturation. |
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Title: Cold testing through full-coverage restorations Author: Miller, S.O. et. al. Journal: JOE,
vol. 30 (10): 695 October 2004 Reviewer: Daniel Bitner, DMD Purpose: The
purpose of this study was to measure the temperature change occurring at the
pulp-dentin junction (PDJ) of extracted premolars restored with PFM or
all-porcelain full coverage restorations compared with non restored premolars
or those restored with full gold crowns during thermal testing with a ice
stick, TFE, or CO2 snow. Materials
and Methods: Ten extracted human
premolars were selected as test samples.
The roots were then sectioned 5 mm below the CEJ, and the pulp contents
removed. A thermal conductive medium
was placed into the pulp chamber, after which, a thermocouple was secured
within the tooth. Thermal testing was
conducted at room temperature. Thermal
testing was first conducted on the intact crowns of the ten samples using a
ice stick, TFE using a saturated cotton pellet, and a 3.5 mm diameter pencil
shaped piece of CO2
snow. All testing
agents were applied to the middle third of the facial surface for 30 seconds,
with measurements of temperature occurring every five seconds. The thermal test was done three times to
each sample. One sample was tested for
2 minutes to evaluate the prolonged effect of the different thermal tests. Crown preps were then done on each of the
extracted teeth and three coronal restorations for each sample were
constructed. The coronal restorations
were a full gold crown, a PFM crown, and an all-porcelain crown. The same procedure for testing the
unprepared samples was then conducted for the prepared samples using the full
gold crown, PFM crown, and all-porcelain crown as a restoration. A thermal conductive medium was placed
between the restoration and the tooth during each test. The all-porcelain crown was then luted into place and tested again. Results:
Comparison of thermal testing methods found no significant difference
between thermal testing methods at 5 seconds for all restoration types. Discussion: The
results of this study indicates that TFE sprayed onto a #2 cotton pellet
provides a more rapid and effective initial temperature reduction than either
ice or CO2 snow when testing non restored or crowned teeth. It was also found that thermal transfer
through PFM and all ceramic crowns was similar to thermal transfer through
non restored teeth. Conclusion: The wide use of PFM and all ceramic
restorations and the possibility that many of these restored teeth may
require endodontic treatment makes it necessary to
have a safe and reliable method to test pulp vitality. |
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Title: In vivo study on the biocompatibility of newly developed calcium phosphate- based root canal sealers Author: Kim, Jin-Su, Baek, Seung-Ho, and Bae, Kwang-Shik Journal: JOE, Vol. 30, No. 10 (p708-711), October 2004. Reviewer: Brian S. Jeon, DMD Purpose: To compare the biocompatibility of new calcium phosphate-based root canal sealers (CAPSEAL I & II) w/ another commercially available calcium phosphate sealers (Apatite Root Sealer I & II) and a ZOE-based sealer (Pulp Canal Sealer EWT). Materials &
Methods:
Results:
Discussion: The early responses of all the groups in this study showed more than moderate inflammation, but the inflammatory reactions decreased w/ time. Biocompatibility is an important consideration when selecting a material for Endodontic therapy because of direct contact w/ the viral tissue. However, the currently used root canal filling materials have a tissue-irritating potential (PCS EWT contains eugenol and zinc ions; ARS contains polyacrylic acid). For this reason, the new calcium phosphate-based sealers will be useful root canal sealers. |
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Title: Identification of resected root-end dentinal cracks: A comparative study of transillumination and dyes. Author: Wright et al Journal: JOE October 2004 Reviewer: Rahul Gupta, DDS Introduction: Root-end resection and ultrasonic preparation are commonly performed during apical surgery and could reveal or potentially create cracks in the root dentin. The dilemma of diagnosing dentinal cracks continues to present a challenge in endodontics. The definitive diagnosis of a failing nonsurgical endodontic case, in many situations, may be determined only during surgical exposure through direct inspection of the root surface. Accurate diagnosis of these cracks would provide the clinician with important information to advise the patient better on the long-term prognosis of the endodontic treatment. The purpose of this in vitro study was to compare the effectiveness of transillumination and dyes in identifying root-end dentinal cracks. Methods and Materials: Fifty maxillary central incisors were de-coronated, and the canals were instrumented to an ISO size 50 at the working length. The apical 3mm of each root was then resected perpendicular to the long axis using a bur in a high-speed handpiece with water spray. Four independent examiners evaluated the root ends at x8 magnification with a surgical operating microscope using · transillumination (group 1) · sodium fluorescein dye (group 2) · caries detect dye (group 3) · methylene blue dye (group4) · methylene blue plus transillumination (group 5). The examiners' ability to identify root ends correctly with and without cracks was analyzed by comparing the data with the predetermined standard (cracked and noncracked) using logistic regression analysis. Results: All techniques used were shown to be more effective than random chance at diagnosing cracks. The areas under the curve (AROC) of the different techniques were as follows: transillumination, 0.81(95 confidence interval); sodium fluorescein, 0.72 (95 confidence interval); caries detector, 0.76 (95 confidence interval); methylene blue, 0.70 (95 confidence interval); and methylene blue plus transillumination, 0.82 (95 confidence interval). Thus, the technique that provided the best AROC, or the best discrimination between cracked and non-cracked resected roots, regardless of rater,was methylene blue plus transillumination. Discussion: There were no statistically significant differences between transillumination alone and methylene blue plus transillumination. Within the parameters of this study, transilluminating the root end, whether alone or in combination with a dye, appears to be the most accurate way of diagnosing root-end dentinal cracks. |
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