M ILITARY M EDICINE, 180, 3:92,2015
The Effectiveness of Endodontic Solvents to Remove Endodontic Sealers COL Jae I. Hwang, DC USA*; Augustine H. Chuang, PhDf; COL Stephanie J. Sidow, DC USA*; COL Kathleen McNally, DC USA*; MAJ Jeremy L. Goodin, MS USAf; James C. McPherson III, PhD f
ABSTRACT Dental emergencies negatively affect troop readiness, especially during combat. Endodontic retreatment, when required, is especially challenging when the removal of endodontic sealer is required. In this study, we investigated the effectiveness of synthetic endodontic solvents to remove endodontic sealers. Fifty capillary tubes (2.7 mm ID x 22 mm L), each filled to 15 mm with either Roth 801, AH Plus, MetaSEAL, or gutta-percha, were stored at 75% humidity for 14 days at 37°C. Ten capillary tubes containing each sealer were treated with either chloroform, xylene, EndoSolv R, EndoSolv E, or no solvent, and then penetrated with D3 ProTaper Universal Retreatment file on the same day. The time for the file to penetrate the length of each sealer was recorded, and the data statistically analyzed. Roth 801 failed to set and was not tested. The file took 3.4 + 0.1, 4.8 ± 0.3, 5.7 ± 0.4, 4.5 ± 0.2, and 10.6 + 1.0 seconds (mean ± SD) to penetrate gutta-percha using chloroform, xylene, EndoSolv R, EndoSolv E, or no solvent, respectively, and was performed by one endodontic resident at one sitting. The time for penetration of gutta-percha with any solvent was significantly faster ( p < 0.05) than for AH Plus or MetaSEAL.The time for AH Plus ranged from 23.1 + 1.0 to 81.5 ± 4.5 seconds. The time for MetaSEAL ranged from 97.2 + 6.1 to >180 seconds. EndoSolv E was the most effective solvent for AH Plus. It took significantly more time to remove MetaSEAL than AH Plus, regardless of the solvent used. Our study indicated that the use of the proper endodontic solvent makes complete removal of a sealer much more effective during retreatment.
INTRODUCTION The rigors of modem combat in austere environment requires soldiers be physically, mentally, and medically well pre pared. Dental care is an integral part of the Army Readiness program.1 During Operation Iraqi Freedom and Operation Enduring Freedom, 20% to 25% of deployed soldiers experi enced a dental emergency during their deployment.2,3 Accord ing to Liewehr,3 for an Army division, this resulted in a potential loss of 18,000 man-days during a 1-year deployment with approximately half of the procedures requiring endodon tic intervention. Endodontic treatment is not without failure with 6% of all root canal requiring retreatment.4 A frequent cause of retreatment is the persistence of a microbial infection in the root canal system and/or the periradicular area,5 necessitating the removal of an old obturation. The goal of retreatment is the
*Tingay Army Dental Clinic, 320 East Hospital Road, Building 320, Fort Gordon, GA 30905. ■(Department of Clinical Investigation, D.D. Eisenhower Army Medical Center, 38th Street and 7th Avenue, Building 38705, Fort Gordon, GA 30905. This study was presented at the Military Health System Research Sym posium, Fort Lauderdale, Florida, August 12-15, 2013. We affirm that we have no financial affiliation (e.g., employment, direct payment, stock holdings, retainers, consultantships, patent licensing arrange ments or honoraria), or involvement with any commercial organization with direct financial interest in the subject or material discussed in this manu script, nor have any such arrangements existed in the past 3 years. Any other potential conflict of interest is disclosed. The opinions expressed in this article are exclusively those of the authors and not necessarily those of the U.S. Army Dental Corps or the Department of the Army. The use of commercial products in this project does not imply endorsement by the U.S. Government. doi: 10.7205/MILMED-D-14-00379
92
complete eradication of the microbial infection and infected root canal filling materials, which are often difficult to remove.6,7 The complete removal of gutta-percha and sealer is necessary to allow effective cleaning, shaping, and refilling of the root canal system. However, complete removal is not always possible.8 Endodontic sealers are used to seal voids between the core material and the root canal system and to prevent leakage from the apical area or coronal restoration. The techniques for removing root canal filling materials include the use of solvents, heat, hand files, rotary files, ultrasonic instruments, and more recently, neodymium-doped yttrium aluminum garnet laser, used either alone or in combination.7-11 Previous studies by Hansen8 and Erdemir et al,12 evaluated the efficacy of solvents using manual instru mentation with Hedstrom files.13 Nickel-titanium rotary files were introduced for the purpose of removing root canal filling materials.14 Rotary files are more efficient than manual instru mentation.15 Advantages of rotary files include maintenance of canal shape and shorter working time. The ProTaper Universal Retreatment file,14,16 used in sequence, is designed to remove the root canal filling material utilizing different lengths, tapers, and apical tip diameters. Numerous studies have proven the efficacy of solvents in softening gutta-percha,12,17 but studies on root canal sealers have been limited to the dissolving capability of solvents.6,1 These studies do not address the mechanical relationship between the efficacy of solvents to remove, dissolve, or dis lodge these materials from the dentinal wall of the root canal. Chloroform, although considered carcinogenic,18 is recognized as the most efficient solvent for root canal retreatment. Other solvents, such as xylene, halothane, eucalyptol, and orange oil, have been tested as alternative solvents.19 EndoSolv R and
MILITARY MEDICINE, Vol. 180, March Supplement 2015
Effectiveness of Endodontic Solvents to Remove Endodontic Sealers EndoSolv E are currently available synthetic endodontic sol vents. EndoSolv R is designed to remove phenol-based resin sealers, and EndoSolv E is designed to remove zinc oxide eugenol-based sealers. The aim of this study is to determine the effectiveness of four different synthetic endodontic solvents and 1 control (no solvent) in the removal of four types of root canal sealers using automated instrumentation with the D3 ProTaper Uni versal Retreatment file. The time required to effectively remove all sealers is an indication of the selection of the proper solvent and the ease of the retreatment process.
200
E n d o d o n t ic S o l v e n t s
MATERIALS AND METHODS Endodontic sealers Roth 801 (ROTH International, Chicago, Illinois), AH Plus (DENTSPLY International, Johnson City, Tennessee), and MetaSEAL (PARKELL, Edgewood, New York) were mixed exactly according to the manufacturer’s instructions and placed in sterile 5-mL plastic syringes. Using a sterile 19-gauge needle, each sealer was placed into a glass capillary tube (2.7 mm internal diameter, 22 mm long, n = 50) to a fill level of 15 mm. Each capillary tube was filled with thermoplasticized gutta-percha (Obtura II; Obtura Spartan Endodontics, Earth City, Missouri) and served as the capillary control. The tubes (4 groups of n = 50 samples; n = 200 total) were placed in a chamber with a 75% relative humid ity at 37°C for 14 days to allow the materials to completely set.20 Next, 10 samples of each sealer were filled from the open capillary end with 5 mm of one of the following solvents: chloroform (Sultan Healthcare, Edgewood, New Jersey), xylene (Sultan Healthcare), EndoSolv R (SEPTODONT, New Castle, Delaware), EndoSolv E (SEPTODONT), and no sol vent as the negative control. A D3 ProTaper Universal Retreatment file, rotating at 500 rpm in a handheld handpiece was used to penetrate each sealer. Care was taken to maintain consistency of the working pressure for each sample by using one endodontic resident. The solvent was refreshed continu ously as needed from the open capillary end. The time for the file to penetrate the 15 mm length of sealer in each tube was recorded in seconds. If penetration was not completed in 180 seconds, the test was terminated and the time recorded. The time of penetration, the dependent variable, was recorded for each sample-solvent combination. The indepen dent variable was the sealer and the solvent in each capillary tube. The mean and standard deviation was calculated for each group from the time recorded for each solvent. The data were analyzed using Tukey-Kramer’s one-way analysis of variance. A “p ” value of
The Effectiveness of Endodontic Solvents to Remove Endodontic Sealers COL Jae I. Hwang, DC USA*; Augustine H. Chuang, PhDf; COL Stephanie J. Sidow, DC USA*; COL Kathleen McNally, DC USA*; MAJ Jeremy L. Goodin, MS USAf; James C. McPherson III, PhD f
ABSTRACT Dental emergencies negatively affect troop readiness, especially during combat. Endodontic retreatment, when required, is especially challenging when the removal of endodontic sealer is required. In this study, we investigated the effectiveness of synthetic endodontic solvents to remove endodontic sealers. Fifty capillary tubes (2.7 mm ID x 22 mm L), each filled to 15 mm with either Roth 801, AH Plus, MetaSEAL, or gutta-percha, were stored at 75% humidity for 14 days at 37°C. Ten capillary tubes containing each sealer were treated with either chloroform, xylene, EndoSolv R, EndoSolv E, or no solvent, and then penetrated with D3 ProTaper Universal Retreatment file on the same day. The time for the file to penetrate the length of each sealer was recorded, and the data statistically analyzed. Roth 801 failed to set and was not tested. The file took 3.4 + 0.1, 4.8 ± 0.3, 5.7 ± 0.4, 4.5 ± 0.2, and 10.6 + 1.0 seconds (mean ± SD) to penetrate gutta-percha using chloroform, xylene, EndoSolv R, EndoSolv E, or no solvent, respectively, and was performed by one endodontic resident at one sitting. The time for penetration of gutta-percha with any solvent was significantly faster ( p < 0.05) than for AH Plus or MetaSEAL.The time for AH Plus ranged from 23.1 + 1.0 to 81.5 ± 4.5 seconds. The time for MetaSEAL ranged from 97.2 + 6.1 to >180 seconds. EndoSolv E was the most effective solvent for AH Plus. It took significantly more time to remove MetaSEAL than AH Plus, regardless of the solvent used. Our study indicated that the use of the proper endodontic solvent makes complete removal of a sealer much more effective during retreatment.
INTRODUCTION The rigors of modem combat in austere environment requires soldiers be physically, mentally, and medically well pre pared. Dental care is an integral part of the Army Readiness program.1 During Operation Iraqi Freedom and Operation Enduring Freedom, 20% to 25% of deployed soldiers experi enced a dental emergency during their deployment.2,3 Accord ing to Liewehr,3 for an Army division, this resulted in a potential loss of 18,000 man-days during a 1-year deployment with approximately half of the procedures requiring endodon tic intervention. Endodontic treatment is not without failure with 6% of all root canal requiring retreatment.4 A frequent cause of retreatment is the persistence of a microbial infection in the root canal system and/or the periradicular area,5 necessitating the removal of an old obturation. The goal of retreatment is the
*Tingay Army Dental Clinic, 320 East Hospital Road, Building 320, Fort Gordon, GA 30905. ■(Department of Clinical Investigation, D.D. Eisenhower Army Medical Center, 38th Street and 7th Avenue, Building 38705, Fort Gordon, GA 30905. This study was presented at the Military Health System Research Sym posium, Fort Lauderdale, Florida, August 12-15, 2013. We affirm that we have no financial affiliation (e.g., employment, direct payment, stock holdings, retainers, consultantships, patent licensing arrange ments or honoraria), or involvement with any commercial organization with direct financial interest in the subject or material discussed in this manu script, nor have any such arrangements existed in the past 3 years. Any other potential conflict of interest is disclosed. The opinions expressed in this article are exclusively those of the authors and not necessarily those of the U.S. Army Dental Corps or the Department of the Army. The use of commercial products in this project does not imply endorsement by the U.S. Government. doi: 10.7205/MILMED-D-14-00379
92
complete eradication of the microbial infection and infected root canal filling materials, which are often difficult to remove.6,7 The complete removal of gutta-percha and sealer is necessary to allow effective cleaning, shaping, and refilling of the root canal system. However, complete removal is not always possible.8 Endodontic sealers are used to seal voids between the core material and the root canal system and to prevent leakage from the apical area or coronal restoration. The techniques for removing root canal filling materials include the use of solvents, heat, hand files, rotary files, ultrasonic instruments, and more recently, neodymium-doped yttrium aluminum garnet laser, used either alone or in combination.7-11 Previous studies by Hansen8 and Erdemir et al,12 evaluated the efficacy of solvents using manual instru mentation with Hedstrom files.13 Nickel-titanium rotary files were introduced for the purpose of removing root canal filling materials.14 Rotary files are more efficient than manual instru mentation.15 Advantages of rotary files include maintenance of canal shape and shorter working time. The ProTaper Universal Retreatment file,14,16 used in sequence, is designed to remove the root canal filling material utilizing different lengths, tapers, and apical tip diameters. Numerous studies have proven the efficacy of solvents in softening gutta-percha,12,17 but studies on root canal sealers have been limited to the dissolving capability of solvents.6,1 These studies do not address the mechanical relationship between the efficacy of solvents to remove, dissolve, or dis lodge these materials from the dentinal wall of the root canal. Chloroform, although considered carcinogenic,18 is recognized as the most efficient solvent for root canal retreatment. Other solvents, such as xylene, halothane, eucalyptol, and orange oil, have been tested as alternative solvents.19 EndoSolv R and
MILITARY MEDICINE, Vol. 180, March Supplement 2015
Effectiveness of Endodontic Solvents to Remove Endodontic Sealers EndoSolv E are currently available synthetic endodontic sol vents. EndoSolv R is designed to remove phenol-based resin sealers, and EndoSolv E is designed to remove zinc oxide eugenol-based sealers. The aim of this study is to determine the effectiveness of four different synthetic endodontic solvents and 1 control (no solvent) in the removal of four types of root canal sealers using automated instrumentation with the D3 ProTaper Uni versal Retreatment file. The time required to effectively remove all sealers is an indication of the selection of the proper solvent and the ease of the retreatment process.
200
E n d o d o n t ic S o l v e n t s
MATERIALS AND METHODS Endodontic sealers Roth 801 (ROTH International, Chicago, Illinois), AH Plus (DENTSPLY International, Johnson City, Tennessee), and MetaSEAL (PARKELL, Edgewood, New York) were mixed exactly according to the manufacturer’s instructions and placed in sterile 5-mL plastic syringes. Using a sterile 19-gauge needle, each sealer was placed into a glass capillary tube (2.7 mm internal diameter, 22 mm long, n = 50) to a fill level of 15 mm. Each capillary tube was filled with thermoplasticized gutta-percha (Obtura II; Obtura Spartan Endodontics, Earth City, Missouri) and served as the capillary control. The tubes (4 groups of n = 50 samples; n = 200 total) were placed in a chamber with a 75% relative humid ity at 37°C for 14 days to allow the materials to completely set.20 Next, 10 samples of each sealer were filled from the open capillary end with 5 mm of one of the following solvents: chloroform (Sultan Healthcare, Edgewood, New Jersey), xylene (Sultan Healthcare), EndoSolv R (SEPTODONT, New Castle, Delaware), EndoSolv E (SEPTODONT), and no sol vent as the negative control. A D3 ProTaper Universal Retreatment file, rotating at 500 rpm in a handheld handpiece was used to penetrate each sealer. Care was taken to maintain consistency of the working pressure for each sample by using one endodontic resident. The solvent was refreshed continu ously as needed from the open capillary end. The time for the file to penetrate the 15 mm length of sealer in each tube was recorded in seconds. If penetration was not completed in 180 seconds, the test was terminated and the time recorded. The time of penetration, the dependent variable, was recorded for each sample-solvent combination. The indepen dent variable was the sealer and the solvent in each capillary tube. The mean and standard deviation was calculated for each group from the time recorded for each solvent. The data were analyzed using Tukey-Kramer’s one-way analysis of variance. A “p ” value of
