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Week of December 5, 2000

Title:Diagnostic Thermal Pulp Testing: A Technique

Author:Selden, Howard S.

Journal:JOE, 26(10): 623, November 2000.

Prepared by: G. Altenburg

Purpose: To present a technique for thermal testing that has proved useful where the usual diagnostic routine was unable to clarify the problem.

M&M:Thermal testing technique is for situations in which sensitivity to hot is the main symptom but the tooth involved is not clear.

          1.  Patient cooperation and understanding of the test procedures is necessary.

          2.  Hot tap water held in the mouth by the patient is the first step.

3. The test starts with moderately warm water, and the temperature is slowly elevated (within tolerable limits) until it provokes the reported oral pain.

4. The patient is instructed not to drink the hot water, but to hold a small amount on the painful side of the mouth until the pain is detected, and then to promptly empty the fluid into a conveniently placed receptacle.

5. The interval of time for remission of the painful response to subside without any intervention is carefully noted.

6. The patient is next informed that, after hot water again induces the pain, a piece of ice will be applied to one tooth at a time to determine whether cold will stop the pain caused by the hot water. When the pain begins to fade the patient should immediately signal by raising a hand.

7. The most likely etiological tooth is tested first and, if negative, then the tests proceed in descending order of probability.

8. The ice is applied to one isolated tooth at a time, as quickly as possible after the onset of the pain induced by hot water.

9. The sick tooth is identified when the ice stops the pain in less time than the previously established remission time. As a rule this difference in the speed of relief is significant. If any doubt remains, the test is redone, applying the ice first to a number of nonsuspect teeth. When the ice is reapplied to the sick tooth pain relief is usually impressive and no uncertainties remain.

Discussion:The subjective basis of thermal testing naturally is totally dependent on the patient and in that sense is limited. Best results in thermal testing are obtained with mature, emotionally stable patients.

Title: A Survey of Participation in Managed Care Programs by Endodontic Specialists.

Author: Pulshipher, C. et al.

Journal: JOE, 26(10):610, November 2000.

Reviewed by:Paul Slusarz, D.M.D.

Purpose: To determine the extent of participation of endodontists in managed care programs.

Materials and Methods:

• In 1994, the Quarterly Survey of Dental Practice (QSDP) utilized a survey to evaluate general dental practitioner participation in managed care programs. This survey was adapted for use in this study (pp. 612-613).
• A 10% stratified random sample of endodontic specialists in the United States were selected for participation in this study and were sent surveys.

Results:

• 229 surveys were returned out of the 331 sent equaling a 69% return.
• Total participation by endodontists responding to this survey in any Health Maintenance Organization and/or Preferred Provider Organization insurance plans was 31.3%; however the total percentage of patients treated under these insurance plans was only 6.6%.
• There were no significant differences with the test group for the number of years in practice, employment status, number of employees, reasons for joining or not joining an HMO or PPO, and alteration of fees due to PPO.
• There were significant regional differences, with the Northeast, Midwest and West having greater participation than the Southeast.
• Also of interest was that those who had been in practice for less than 5 years indicated the lowest participation in managed care plans.
• When considering the reasons for joining either and HMO or PPO, the most frequently chosen responses were an opportunity to expand their patient base (28.3%) and joining because referring doctors joined (28.3%).
• When evaluating the reasons for not joining an HMO of PPO, the survey showed that most did not join because of unattractive fee schedule offered by the plan (48.5%).

Discussion: Although participation in various managed care programs by endodontists in this survey was close to one-third, the total number of patients treated under these plans was low. It appears from this survey that the overall impact of managed care plans, specifically HMO and PPO, is not widespread. Endodontists seem to be unwilling to accept other than a small reduction in fees to participate in managed care plans, and they desire to retain full control of their dental practices.

Conclusion: It does not appear from the results of this survey that managed care insurance has a significant impact on the practice of endodontics.

Title: Measurement of endodontic file lengths: a density profile plot analysis

Author: Piepenbring, ME, et al

Journal: J of Endodontics, 26(10):610, October 2000

Reviewer: Dr. Mark Wang

Purpose: To evaluate measurements of endodontic files of known length and diameter using a density profile plot analysis.

Materials & Method:

• 10 single-rooted teeth with relatively straight roots in cadaver specimens were used.
• The crowns of the teeth were removed and a rectangular orthodontic wire, 5.13 mm in length, was placed horizontally on the occlusal surface to serve as a calibration reference point.
• The #8, #10, #15, and #20 FlexOfiles were measured to the nearest 0.5 mm and then placed to four working lengths that terminated within the apical third of each root.
• A GE X-ray unit and a Schick CDR #2 sensor were used to digitally acquire 160 images.
• The digital images were placed in random order and an independent, blinded investigator determined the file length using a density profile plot analysis.
• The measurements generated by the histogram analysis (experimental) were compared with the original clinical measurements.
• The paired t test, intraclass correlation coefficient, and the Bradley-Blackwood test were used to assess reliability.

Results:

• The means of the experimental measurements of all file sizes were within 0.5 mm of the known lengths and were always shorter than the known lengths.
• Also, the larger the file size the less deviation from the known lengths: #20, -0.16mm (p=0.0001); #15, -0.21mm (p=0.0001); #10, -0.34mm (p=0.0001); and #8, -0.45 mm (p=0.0001).

Conclusion: This study demonstrated that the density profile plot analysis might be a useful adjunct for the measurement of endodontic file lengths on a digital image.

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Week of December 12, 2000

Title: Pain Reduction in Untreated Irreversible Pulpitis Using an Intraosseous Injection of Depo-Medrol

Author:Gallatin, E. and et al

Journal:Journal of Endodontics, 26(11): 633-638, 2000

Prepared by:Andrew W. Chan, DDS

Purpose:To evaluate pain reduction in untreated irreversible pulpitis using an intraosseous injection of Depo-Medrol in a prospective, randomized, double blind, and placebo-controlled study.

Materials & Methods:Forty adult patients presenting for emergency treatment participated in this study. Patients included in this study had a tooth with a clinical diagnosis of irreversible pulpitis and actively had spontaneous moderate to severe pain associated with the tooth. Various clinical and preoperative parameters were recorded on each patient. Each patient was asked to rate their pain on a scale from 0 to 3. Zero indicated no pain. Forty patients were given an intraosseous injection of either 1ml of methylprednisolone (Depo-Medrol) or 1ml of 0.9% preservative free sterile saline placebo. The blinded solutions were administered via the intraosseous injection using the Stabident system. At the conclusion of the appointment, the patient was given a return date for 1 week to start the root canal treatment, as well as medications and a patient questionnaire to take home. Each patient received twenty 600mg tablets of ibuprofen and was instructed to take the ibuprofen first for pain relief. Patients were also given 20 tablets of Tylenol #3 and were instructed to take them only if the ibuprofen did not control the pain. Each patient received a 7-day questionnaire to be completed every morning on arising. They were instructed to record pain and percussion pain using the same 4-point scale used for the initial pain recordings.

Results:The Depo-Medrol group consisted of 19 patients, whereas the saline group consisted of 21 patients. There was no statistically significant difference between the Depo-Medrol group and the saline placebo group for any of the preoperative parameters. Over the 7-day observation period, the subjects who received the intraosseous injections of Depo-Medrol reported significantly less pain and percussion pain while taking significantly fewer pain medications.

Discussion: There are situations that arise, admittedly rare, when the intraosseous injection of Depo-Medrol could be used to temporarily alleviate symptoms of irreversible pulpitis until definitive treatment can be rendered. One situation would be when there are an inordinate number of emergency patients, and all cannot be clinically treated due to lack of time or staff support. Another example may be when the tooth exhibits unusual coronal/root anatomy or partially calcified canals, not allowing the practitioner to adequately debride the tooth due to time constraints. Another situation may be anesthetic failure when all options have been exhausted but the dentin or pulp cannot be entered due to extreme pain. Whichever the case an intraosseous injection of Depo-Medrol can clinically reduce the patient’s pain to manageable levels, up to 7 days, before receiving endodontic therapy

Title: Antimicrobial substantivity of bovine root dentin exposed to different chlorhexidine delivery vehicles.

Author: Lenet BJ et al

Journal: JOE 26: 11; pg 652, Nov, 2000

Reviewer: M.Oller

Purpose: To assess the efficacy of two chlorhexidine (CHX) delivery vehicles, a novel controlled-release device and a gel, to affect antimicrobial substantivity of bovine root canal dentin.

Materials and Methods: 60 bovine incisor root specimens were prepared with standardized length (10mm) and canal diameter (3.3mm), and coated externally with nail polish.

- Specimens were divided in to four equal groups and their canals medicated for 7 days with either:

I) An experimental controlled-release device containing 25% CHX (shaped like a gutta percha cone) that was immersed in sterile saline.

II) 2% CHX experimental gel

III) Ca (OH)₂ paste

IV) sterile saline (positive control)

- After medication, the canals of the specimens were inoculated with Enterococcus faecalis of 21 days.

- Root canal dentin sample ranging in depth from 0.1 to 0.45mm were then obtained using sterile round burs of ascending diameter.

- Each dentin sample was placed in separate test tube containing BHI broth and incubated for 24h.

- The optical density (OD) of the broth was then measured spectrophotometrically at 540nm. *(The positive control group showed significantly higher mean OD values than the three test groups).

Results:

• The CHX controlled-release device group showed significantly lower OD values that the Ca (OH)₂ groups; however only at dentin depths up to 0.2mm.

• The CHX gel group consistently showed significantly lower OD values than both the CHX controlled-release device and Ca (OH)₂ groups.

Conclusion: The results suggest that bovine root canals medicated with 2% CHX gel for 7 days acquire antimicrobial properties for at least.

Comments:

- The concentration of CHX controlled-release device was diluted as it was shaped like gutta percha and had a diameter of 0.6mm. The devices were very small relative to the enlarged canals of the bovine teeth test. Also, saline in which the devices were placed with was periodically refilled. Thus, the findings are questionable in regards to this releasing device.

- The possibility that the viscous CHX gel remained attached to the canal wall could not be ruled out. Thus, it can not be concluded whether the bacterial inhibition was due to the antimicrobial substantivity or the residue of the gel. Also, if the gel remained on the walls it would compromise the seal of a root filling.

Title: pH Changes in Root Dentin after Root Canal Dressing with Gutta-Percha Points Containing Calcium Hydroxide

Author: Schafer & Behaissi

Journal: JOE, Vol. 26, No. 11, pp 665 – 667, November 2000.

Reviewed by: Tom Goebel

Purpose: To compare the alkalization of root dentin after the use of gutta percha points containing calcium hydroxide and the aqueous calcium hydroxide suspension.

M & M:

• gutta-percha points containing calcium hydroxide manufactured by Roeko
• pH measurements in this study were performed using a pH microelectrode that was calibrated before and after each series of measurements with 2 buffer solutions of a known pH
• 140 extracted human anterior teeth were used
• teeth were accessed and instrumented to MAF 40 within 1 mm of apex
• root canals were flushed with 5 ml NaOCl between files and rinsed with 10 ml isotonic saline after completion of instrumentation
• smear layer was removed with 2 ml 17% EDTA for 5 min & root canals were dried with paper points
• 60 teeth were filled with aqueous calcium hydroxide via lentulo
• 60 root canals were moistened with 25 ul isotonic saline and then fitted with size 40 gutta-percha cones containing calcium hydroxide
• root canals of 20 control teeth were filled with isotonic saline
• access cavities were sealed with Cavit & teeth were stored in saline @ 37 degrees Celsius up to the CEJ
• after 24 h, 3 days & 7 days, 10 teeth from each group were grooved & split longitudinally so that the pH of the root could be measured at 4 points between the root canal wall and the root surface
• to measure the pH, small holes were drilled at the points and then 2 ul of isotonic saline was added to each cavity. Data from the 4 points was analyzed.

Results:

• control teeth had no differences of the pH at any measurement points at 24 h or 7 days
• aqueous calcium hydroxide suspension always resulted in higher root dentin pH compared to the gutta-percha points and control teeth; the differences were statistically significant; maximum root surface pH 9.1 while mid-root dentin pH 12.1
• after gutta-percha points containing calcium hydroxide remained inside the root canals, the pH @ measuring points 1 & 2 was significantly higher than the controls; no other points were significantly different; maximum root surface pH typically < 8.
• the maximal alkalinization of the root dentin at all points was always 24 hr after filling with aqueous calcium hydroxide
• after 3 days, the gutta-percha points no longer had a detectable alkalinization effect

Conclusion: Gutta percha points containing calcium hydroxide were unable to alkalinize the root surface over a 7 day period while the aqueous calcium hydroxide suspension was able to alkalinize the root surface for a prolonged period of time.

Title: Influence of mixing vehicle on dissociation of calcium hydroxide in solution

Author: Safavi et al.

Journal: J Endodon 26(10):649, November 2000.

Reviewed by: Barry Hoch

Purpose: To evaluate the extent of dissociation of calcium hydroxide in two nonaqueous mixing vehicles advocated for endodontic use.

Materials and Method:

• Mixtures of glycerin or propylene glycol with ultrapure water were prepared in centrifuge tubes by serial dilution.
• Calcium hydroxide was added to the solutions and saturated upon shaking.
• Undissolved calcium hydroxide was separated by centrifugation, and the conductivity of the liquids was measured at 23^°C, 30^°C, and 37^°C.
• Controls measured the conductivity of the solutions without calcium hydroxide.

Results:

• As glycerin-water concentrations increased (from 20-100%) when mixed with calcium hydroxide, the conductivity drastically decreased.
• At higher concentrations of propylene glycol, (from 40-100%), the conductivity values decreased as well.
• There was no overall significant difference of conductivity values at different temperatures.

Discussion: When dissolved in aqueous solutions (water), calcium hydroxide dissociates into hydroxide ions and calcium ions. It is thought that it is the presence of the hydroxide ions in solution that make it [calcium hydroxide] alkaline and thus antimicrobial. This study posed the question on whether or not using nonaqueous mixing vehicles, such as glycerin and propylene glycol, would affect the dissociation or concentration of the ionized substances (calcium and hydroxide), thus affecting its antimicrobial ability.

The measuring of conductivity in this study measures the capacity of a solution to transmit an electrical current, which is proportional to the concentration of ionized substances in solution. Thus, if the two vehicles (at higher concentrations) for calcium hydroxide delivery reduced the conductivity, it is suggested that the dissociation of calcium hydroxide ions in this environment would be compromised, potentially affecting the effectiveness of calcium hydroxide as a root canal dressing.

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Temple University School of Dentistry. All contents copyright (C) 1996. All rights reserved.
Created: September 20, 2000 Revised: URL:

Roy H. Stevens, DDS, MS; Wanda Gordon, D.M.D. - Comments to author:	wgordon@dental.temple.edu
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