An In Vitro Evaluation of Apical Leakage in Gutta-percha ...
Effect of gutta-percha solvents on calcium and phosphorus levels of cut human dentin
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0099-2399/97/2310-0614503.00/0 JOURNALOF ENDODONTICS Copyright © 1997 by The American Association of Endodontists Printed in U.S.A. VOL. 23, NO. 10, OCTOBER 1997 Effect of Gutta-Percha Solvents on Calcium and Phosphorus Levels of Cut Human Dentin Daniel Kaufman, DMD, Chaim Mor, DMD, Adam Stabholz, DMD, and Ilan Rotstein, CD Fresh intact human teeth were cut and treated with 3 commonly used gutta-percha solvents: chloro- form, xylene, and Endosolv-E. Treatment consisted of embedding the specimens of each group for 15 or 30 min in the test solution. After each time in- terval, the specimens were rinsed, dried, and pre- pared for surface energy dispersive spectrometric analysis. The calcium and phosphorus levels in each specimen were recorded and the differences between the test groups were statistically ana- lyzed. The changes in the calcium and phosphorus levels following treatment with the gutta-percha solvents were minimal and statistically nonsignifi- cant. Solvents are often used during endodontic retreatments to facilitate removal of gutta-percha and sealers from the root canal system. Common gutta-percha solvents are chloroform and xylene as well as some commercially prepared agents. Solvents such as ethyl chloroform, eucalyptol, terpenes, and halothane have also been advocated (1-2). Although chloroform proved to be very effective in dissolving most types of gutta-percha, its possible tissue toxicity has been a subject of concern (3-4). Additionally, its carcinogenic potential urged investigators to seek alternative agents (2, 4-6). During endodontic retreatment procedures the radicular and coronal dentin are exposed to gutta-percha solvents deposited in the root canal orifice. Such solvents may alter the chemical com- position of the dentin surface and affect its interaction with mate- rials used for root canal obturation and coronal restoration. The purpose of this study was, therefore, to assess histochemically the effect of chloroform, xylene, and Endosolv-E on the calcium and phosphorus levels of cut human dentin surface. MATERIALS AND METHODS Ten fresh intact premolars of young adults, extracted for orth- odontic reasons, were used. Two horizontal slices, 1 mm thick, were cut below the central fossae using a diamond disc rotated at slow speed. Each slice, including both dentin and enamel, was further cut into 4 segments. A total of 80 specimens were then placed in an ultrasonic bath for 10 min to remove remnants of debris, dried at room temperature, and sealed in individual glass assay tubes. The specimens were divided into 6 experimental and 2 control groups of 10 specimens each. Each experimental group was treated for 15 or 30 rain with one of the following gutta-percha solvents: chloroform (Protarom Chemicals, Haifa, Israel), xylene (Protarom Chemicals, Haifa, Israel), and Endosolv-E (Septodont, Paris, France). Sterile saline solution was used as control. Treatment consisted of pipetting 0.5 ml of each solution into the assay tubes, totally embedding the specimen in the solution. The assay tubes were then placed in a dry incubator at 37°C. At each time interval, the specimens were removed from the incubator, thoroughly rinsed with distilled water, dried on soft absorbent paper at room temperature, and prepared for surface energy dispersive spectrometric analysis. Levels of calcium and phosphorus in the dentin surface of each specimen were measured using a JSM-840A scanning electron microscope (JEOL, Tokyo, Japan) and an AN1000 energy disper- sive spectrometer (Link-Oxford, High Wycombe, G.B.) with a minimum detectable level of 300 ppm. Each specimen was irra- diated at the center and at two other equidistant areas at a voltage of 15 KV for 60 s. The mineral content was measured as % weight after applying the computerized Z.A.F. correction method. Changes in the mineral levels were recorded and the differences between the groups were statistically analyzed using the Mann- Whitney U-test. RESULTS Chloroform increased the phosphorus levels after 15 min and the calcium and phosphorus levels after 30 min. Xylene increased the calcium levels after 30 min and phosphorus levels after 15 and 30 min. Endosolv-E increased the calcium and phosphorus levels after 15 and 30 min. None of these changes were statistically significant. 614 DISCUSSION The possible cytotoxic effects of chloroform and xylene have been reported in various studies (3-5). Some authors, however, claim that careful usage of chloroform does not involve any clin- ical, legal, or ethical complications in the dental practice (7). In our study, all three gutta-percha solvents seemed to have similar ef- fects on the dentin. Therefore, the clinician should use his judg- ment to select the appropriate solvent for the endodontic retreat- ment procedure.
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Transcript of Effect of gutta-percha solvents on calcium and phosphorus levels of cut human dentin
0099-2399/97/2310-0614503.00/0 JOURNAL OF ENDODONTICS Copyright © 1997 by The American Association of Endodontists
Printed in U.S.A. VOL. 23, NO. 10, OCTOBER 1997
Effect of Gutta-Percha Solvents on Calcium and Phosphorus Levels of Cut Human Dentin
Daniel Kaufman, DMD, Chaim Mor, DMD, Adam Stabholz, DMD, and Ilan Rotstein, CD
Fresh intact human teeth were cut and treated with 3 commonly used gutta-percha solvents: chloro- form, xylene, and Endosolv-E. Treatment consisted of embedding the specimens of each group for 15 or 30 min in the test solution. After each time in- terval, the specimens were rinsed, dried, and pre- pared for surface energy dispersive spectrometric analysis. The calcium and phosphorus levels in each specimen were recorded and the differences between the test groups were statistically ana- lyzed. The changes in the calcium and phosphorus levels following treatment with the gutta-percha solvents were minimal and statistically nonsignifi- cant.
Solvents are often used during endodontic retreatments to facilitate removal of gutta-percha and sealers from the root canal system. Common gutta-percha solvents are chloroform and xylene as well as some commercially prepared agents. Solvents such as ethyl chloroform, eucalyptol, terpenes, and halothane have also been advocated (1-2). Although chloroform proved to be very effective in dissolving most types of gutta-percha, its possible tissue toxicity has been a subject of concern (3-4). Additionally, its carcinogenic potential urged investigators to seek alternative agents (2, 4 -6) .
During endodontic retreatment procedures the radicular and coronal dentin are exposed to gutta-percha solvents deposited in the root canal orifice. Such solvents may alter the chemical com- position of the dentin surface and affect its interaction with mate- rials used for root canal obturation and coronal restoration. The purpose of this study was, therefore, to assess histochemically the effect of chloroform, xylene, and Endosolv-E on the calcium and phosphorus levels of cut human dentin surface.
M A T E R I A L S AND M E T H O D S
Ten fresh intact premolars of young adults, extracted for orth- odontic reasons, were used. Two horizontal slices, 1 mm thick, were cut below the central fossae using a diamond disc rotated at slow speed. Each slice, including both dentin and enamel, was further cut into 4 segments. A total of 80 specimens were then placed in an ultrasonic bath for 10 min to remove remnants of
debris, dried at room temperature, and sealed in individual glass assay tubes. The specimens were divided into 6 experimental and 2 control groups of 10 specimens each.
Each experimental group was treated for 15 or 30 rain with one of the following gutta-percha solvents: chloroform (Protarom Chemicals, Haifa, Israel), xylene (Protarom Chemicals, Haifa, Israel), and Endosolv-E (Septodont, Paris, France). Sterile saline solution was used as control. Treatment consisted of pipetting 0.5 ml of each solution into the assay tubes, totally embedding the specimen in the solution. The assay tubes were then placed in a dry incubator at 37°C. At each time interval, the specimens were removed from the incubator, thoroughly rinsed with distilled water, dried on soft absorbent paper at room temperature, and prepared for surface energy dispersive spectrometric analysis.
Levels of calcium and phosphorus in the dentin surface of each specimen were measured using a JSM-840A scanning electron microscope (JEOL, Tokyo, Japan) and an AN1000 energy disper- sive spectrometer (Link-Oxford, High Wycombe, G.B.) with a minimum detectable level of 300 ppm. Each specimen was irra- diated at the center and at two other equidistant areas at a voltage of 15 KV for 60 s. The mineral content was measured as % weight after applying the computerized Z.A.F. correction method. Changes in the mineral levels were recorded and the differences between the groups were statistically analyzed using the Mann- Whitney U-test.
RESULTS
Chloroform increased the phosphorus levels after 15 min and the calcium and phosphorus levels after 30 min. Xylene increased the calcium levels after 30 min and phosphorus levels after 15 and 30 min. Endosolv-E increased the calcium and phosphorus levels after 15 and 30 min. None of these changes were statistically significant.
614
DISCUSSION
The possible cytotoxic effects of chloroform and xylene have been reported in various studies (3-5). Some authors, however, claim that careful usage of chloroform does not involve any clin- ical, legal, or ethical complications in the dental practice (7). In our study, all three gutta-percha solvents seemed to have similar ef- fects on the dentin. Therefore, the clinician should use his judg- ment to select the appropriate solvent for the endodontic retreat- ment procedure.
Vol. 23, No. 10, October 1997
The authors are affiliated to the Department of Endodontice, The Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel. Address requests for reprints to Dr. Dany Kaufman, Department of Endodontics, Fac- ulty of Dental Medicine, P.O. Box 12272, Jerusalem 91120, Israel.
References
1, 1, Kaplowitz G J, Evaluation of gutta-percha solvents, J Endodon 1990; 16:539-40.
Effect of Gutta-Percha Solvents on Human Dentin 615
2. Wennberg A, Orstavic D. Evaluation of alternatives to chloroform in endodontic practice. Endod Dent Traumatol 1989;5:234-7.
3. Torkelson TR, Oyen F, Rowe VK. The toxicity of chloroform as deter- mined by single and repeated exposure of laboratory animals. Am Ind Hyg Assoc J 1976;37:697-705.
4. Barbosa SV, Burkard DH, Spangberg LSW. Cytotoxic effects of gutta- percha solvents. J Endodon 1994;20:6-8.
5. Wourms D J, Campbell AD, Hicks ML, Pelleu GB Jr. Alternative sol- vents to chloroform for gutta-percha removal. J Endodon 1990;16:224-6.
6. Wilcox LR. Endodontic retreatment with Haloten versus chloroform solvents. J Endodon 1995;21:305-7.
7. McDonald MN, Donald EV. Chloroform in the endodontic operatory. J Endodon 1992;18:301-4.
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