Which treatment protocol, among classical methods and/or various laser applications is the most effective in root canal disinfection, in vitro? A systematic review
ABSTRACT
Purpose: The aim of this systematic review was to answer the question “Which treatment protocol, am- ong classical methods and/or various laser applica- tions is the most effective in root canal disinfection, in vitro”. Materials and Methods: A MEDLINE, a Co- chrane and an Embase search (three specified search- es) were conducted to identify randomized controlled trials (RCT) until June 2010, conducted on human teeth and published in English, German or French language, examining the root canal disinfection after the use of lasers with or without mechanical instru-mentation. Additionally, hand search was conducted and contact with authors, when needed. Results: The MEDLINE, the Cochrane and the EMBASE search identified 240, 28, and 35 published articles, respec-tively. Ten articles from the MEDLINE and 5 articles from the Cochrane search (that were also identified in the MEDLINE search) met the inclusion and va-lidity assessment criteria. In E. faecalis elimination, instrumentation of the root canal and diode laser/665 nanometer/1 Watt (diode laser/665 nm/1 W) irradia-tion with the combined effect of Methylene Blue (MB) as photosensitizing agent (logCFU/ml = 1636) seemed to be the best method. In P. aeruginosa and in A.naeslundii elimination, instrumentation of the root canal followed by irrigation with 5, 25% NaOCl (log-CFU/ml = 0) seemed to be the best method. In gen-eral, instrumentation of the root canal followed by irrigation with 5, 25% NaOCl (logCFU/ml = 0) and instrumentation of the root canal and Er: YAG laser/ 2940 nm/0.8 W irradiation (logCFU/ml = 1924) seemed to be the best (polymicrobial studies). Conclusions: There are treatment protocols with the assistance or not of laser irradiation that can eliminate E. faecalis, E. coli and S. aureus inside the root canal. However, there is a serious number of S. anginosus, F. nuclea-tum, A. naeslundii and P. aeruginosa that remain in-side the root canal even after laser irradiation. New research is needed in order to set a treatment proto-col effective in the root canal disinfection from all bac-teria that are related to endodontic origin pathology.
Purpose: The aim of this systematic review was to answer the question “Which treatment protocol, am- ong classical methods and/or various laser applica- tions is the most effective in root canal disinfection, in vitro”. Materials and Methods: A MEDLINE, a Co- chrane and an Embase search (three specified search- es) were conducted to identify randomized controlled trials (RCT) until June 2010, conducted on human teeth and published in English, German or French language, examining the root canal disinfection after the use of lasers with or without mechanical instru-mentation. Additionally, hand search was conducted and contact with authors, when needed. Results: The MEDLINE, the Cochrane and the EMBASE search identified 240, 28, and 35 published articles, respec-tively. Ten articles from the MEDLINE and 5 articles from the Cochrane search (that were also identified in the MEDLINE search) met the inclusion and va-lidity assessment criteria. In E. faecalis elimination, instrumentation of the root canal and diode laser/665 nanometer/1 Watt (diode laser/665 nm/1 W) irradia-tion with the combined effect of Methylene Blue (MB) as photosensitizing agent (logCFU/ml = 1636) seemed to be the best method. In P. aeruginosa and in A.naeslundii elimination, instrumentation of the root canal followed by irrigation with 5, 25% NaOCl (log-CFU/ml = 0) seemed to be the best method. In gen-eral, instrumentation of the root canal followed by irrigation with 5, 25% NaOCl (logCFU/ml = 0) and instrumentation of the root canal and Er: YAG laser/ 2940 nm/0.8 W irradiation (logCFU/ml = 1924) seemed to be the best (polymicrobial studies). Conclusions: There are treatment protocols with the assistance or not of laser irradiation that can eliminate E. faecalis, E. coli and S. aureus inside the root canal. However, there is a serious number of S. anginosus, F. nuclea-tum, A. naeslundii and P. aeruginosa that remain in-side the root canal even after laser irradiation. New research is needed in order to set a treatment proto-col effective in the root canal disinfection from all bac-teria that are related to endodontic origin pathology.
Cite this paper
nullTheodosopoulou, J. , Chochlidakis, K. and Tsigarida, A. (2011) Which treatment protocol, among classical methods and/or various laser applications is the most effective in root canal disinfection, in vitro? A systematic review. Open Journal of Stomatology, 1, 126-139. doi: 10.4236/ojst.2011.14020.
nullTheodosopoulou, J. , Chochlidakis, K. and Tsigarida, A. (2011) Which treatment protocol, among classical methods and/or various laser applications is the most effective in root canal disinfection, in vitro? A systematic review. Open Journal of Stomatology, 1, 126-139. doi: 10.4236/ojst.2011.14020.
References
[1] Foschi, F., Cavrini, F., Montebugnoli, L., Stashenko, P., Sambri, V. and Prati, C. (2005) Detection of bacteria in endodontic samples by polymerase chain reaction assays and association with defined clinical signs in Italian patients. Oral Microbiology and Immunology, 20, 289-295. doi:10.1111/j.1399-302X.2005.00227.x [2] Sassone, L., Fidel, R., Faveri, M., Fidel, S., Fiqueiredo, L. and Feres, M. (2008) Microbiological evaluation of primary endodontic infections in teeth with and without sinus tract. International Endodontic Journal, 41, 508-515. doi:10.1111/j.1365-2591.2008.01397.x [3] Gomes, B., Pinheiro, E., Gadê-Neto, C., Sousa, E., Ferraz, C., Zaia, A., et al. (2004) Microbiological examination of infected dental root canals. Oral Microbiology and Immunology, 19, 71-76. doi:10.1046/j.0902-0055.2003.00116.x [4] Gomes, B., Jacinto, R., Pinheiro, E., Sousa, E., Zaia, A., Ferraz, C., et al. (2005) Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia and Prevotella nigrescens in endodontic lesions detected by culture and by PCR. Oral Microbiology and Immunology, 20, 211-215. doi:10.1111/j.1399-302X.2005.00214.x [5] Sousa-Neto, M., Marchesan, M., Pécora, J., Junior, A., Silva-Sousa, Y. and Saquy, P. (2002) Effect of Er:YAG laser on adhesion of root canal sealers. Journal of Endodontics, 28, 185-187. doi:10.1097/00004770-200203000-00010 [6] Schoop, U., Kluger, W., Dervisbegovic, S., Goharkhay, K., Wernisch, J., Georgopoulos, A., et al. (2006) Innovative wavelengths in endodontic treatment. Lasers in Surgery and Medicine, 38, 624-630. doi:10.1002/lsm.20331 [7] Jha, D., Guerrero, A., Ngo, T., Helfer, A. and Hasselgren, G. (2006) Inability of laser and rotary instrumentation to eliminate root canal infection. Journal of the American Dental Association, 137, 67-70. [8] Garcez, A., Ribeiro, M., Tegos, G., Nú?ez, S., Jorge, A. and Hamblin, M. (2007) Antimicrobial photodynamic therapy combined with conventional endodontic treatment to eliminate root canal biofilm infection. Lasers in Surgery and Medicine, 39, 59-66. doi:10.1002/lsm.20415 [9] Blum, J., Michailesco, P. and Abadie, M. (1997) An evaluation of the bactericidal effect of the Nd:YAP laser. Journal of Endodontics, 23, 583-585. doi:10.1016/S0099-2399(06)81127-1 [10] Dostálová, T., Jelínková, H., Housová, D., Sulc, J., Neme?, M., Dusková, J., et al. (2002) Endodontic treatment with application of Er:YAG laser waveguide radiation disinfection. Journal of Clinical Laser Medicine and Surgery, 20, 135-139. doi:10.1089/104454702760090218 [11] Fegan, S. and Steiman, H. (1995) Comparative evaluation of the antibacterial effects of intracanal Nd:YAG laser irradiation: an in vitro study. Journal of Endodontics, 21, 415-417. doi:10.1016/S0099-2399(06)80827-7 [12] Fonseca, M., Júnior, P., Pallota, R., Filho, H., Denardin, O., Rapoport, A., et al. (2008) Photodynamic therapy for root canals infected with Enterococcus faecalis. Photomedicine and Laser Surgery, 26, 209-213. doi:10.1089/pho.2007.2124 [13] Gordon, W., Atabakhsh, V., Meza, F., Doms, A., Nissan, R., Rizoiu, I., et al. (2007) The antimicrobial efficacy of the erbium, chromium:yttrium-scandium-gallium-garnet laser with radial emitting tips on root canal dentin walls infected with Enterococcus faecalis. Journal of the American Dental Association, 138, 992-1002. [14] Gutknecht, N., Nuebler-Moritz, M., Burghardt, S. and Lampert, F. (1997) The efficiency of root canal disinfection using a holmium:yttrium-aluminum-garnet laser in vitro. Journal of Clinical Laser Medicine and Surgery, 15, 75-78. [15] Hardee, M., Miserendino, L., Kos, W. and Walia, H. (1994) Evaluation of the antibacterial effects of intracanal Nd:YAG laser irradiation. Journal of Endodontics, 20, 377-380. doi:10.1016/S0099-2399(06)80294-3 [16] Kreisler, M., Kohnen, W., Beck, M., Al-Haj, H., Christoffers, A., G?tz, H., et al. (2003) Efficacy of NaOCl/H2O2 irrigation and GaAlAs laser in decontamination of root canals in vitro. Lasers in Surgery and Medicine, 32, 189-196. doi:10.1002/lsm.10148 [17] Moritz, A., Gutknecht, N., Goharkhay, K., Schoop, U., Wernisch, J. and Sperr, W. (1997) In vitro irradiation of infected root canals with a diode laser: Results of microbiologic, infrared spectrometric, and stain penetration examinations. Quintessence International, 28, 205-209. [18] Moshonov, J., Orstavik, D., Yamauchi, S., Pettiette, M. and Trope, M. (1995) Nd:YAG laser irradiation in root canal disinfection. Endodontics & dental traumatology, 11, 220-224. doi:10.1111/j.1600-9657.1995.tb00492.x [19] Perin, F., Fran?a, S., Silva-Sousa, Y., Alfredo, E., Saquy, P., Estrela, C., et al. (2004) Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection. Australian Endodontic Journal, 30, 20-22. doi:10.1111/j.1747-4477.2004.tb00162.x [20] Ramsk?ld, L., Fong, C. and Str?mberg, T. (1997) Thermal effects and antibacterial properties of energy levels required to sterilize stained root canals with an Nd:YAG laser. Journal of Endodontics, 23, 96-100. doi:10.1016/S0099-2399(97)80253-1 [21] Schoop, U., Goharkhay, K., Klimscha, J., Zagler, M., Wernisch, J., Georgopoulos, A., et al. (2007) The use of the erbium, chromium:yttrium-scandium-gallium-garnet laser in endodontic treatment: the results of an in vitro study. Journal of the American Dental Association, 138, 949-955. [22] Schoop, U., Moritz, A., Kluger, W., Patruta, S., Goharkhay, K., Sperr, W., et al. (2002) The Er:YAG laser in endodontics: results of an in vitro study. Lasers in Surgery and Medicine, 30, 360-364. doi:10.1002/lsm.10054 [23] Soukos, N., Chen, P., Morris, J., Ruggiero, K., Abernethy, A., Som, S., et al. (2006) Photodynamic therapy for endodontic disinfection. Journal of Endodontics, 32, 979- 984. doi:10.1016/j.joen.2006.04.007 [24] Vezzani, M., Pietro, R., Silva-Sousa, Y., Brugnera-Junior, A. and Sousa-Neto, M. (2006) Disinfection of root canals using Er:YAG laser at different frequencies. Photomedicine and Laser Surgery, 24, 499-502. doi:10.1089/pho.2006.24.499 [25] Folwaczny, M., Mehl, A., Jordan, C. and Hickel, R. (2002) Antibacterial effects of pulsed Nd:YAG laser radiation at different energy settings in root canals. Journal of Endodontics, 28, 24-29. doi:10.1097/00004770-200201000-00006 [26] Bergmans, L., Moisiadis, P., Teughels, W., Van Meerbeek, B., Quirynen, M. and Lambrechts, P. (2006) Bactericidal effect of Nd:YAG laser irradiation on some endodontic pathogens ex vivo. International Endodontic Journal, 39, 547-557. doi:10.1111/j.1365-2591.2006.01115.x [27] Moritz, A., Schoop, U., Goharkhay, K., Jakolitsch, S., Kluger, W., Wernisch, J., et al. (1999) The bactericidal effect of Nd:YAG, Ho:YAG, and Er:YAG laser irradiation in the root canal: An in vitro comparison. Journal of Clinical Laser Medicine and Surgery, 17, 161-164. [28] Mehl, A., Folwaczny, M., Haffner, C. and Hickel, R. (1999) Bactericidal effects of 2.94 μm Er:YAG-laser radiation in dental root canals. Journal of Endodontics, 25, 490-493. doi:10.1016/S0099-2399(99)80288-X [29] Piccolomini, R., D’Arcangelo, C., D’Ercole, S., Catamo, G., Schiaffino, G. and De Fazio, P. (2002) Bacterologic evaluation of the effect of Nd:YAG laser irradiation in experimental infected root canals. Journal of Endodontics, 28, 276-278. doi:10.1097/00004770-200204000-00004 [30] Bergmans, L., Moisiadis, P., Huybrechts, B., Van Meerbeek, B. and Quirynen, M.P.L. (2008) Effect of photo-activated disinfection on endodontic pathogens ex vivo. International Endodontic Journal, 41, 227-239. doi:10.1111/j.1365-2591.2007.01344.x [31] Wang, Q., Zhang, C. and Yin, X. (2007) Evaluation of the bactericidal effect of Er,Cr:YSGG, and Nd:YAG lasers in experimentally infected root canals. Journal of Endodontics, 33, 830-832. doi:10.1016/j.joen.2007.03.017 [32] De Souza, E., Cai, S., Simionato, M. and Lage-Marques, J. (2008) High-power diode laser in the disinfection in depth of the root canal dentin. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology & Endodontics, 106, 68-72. doi:10.1016/j.tripleo.2008.02.032 [33] Foschi, F., Fontana, C., Ruggiero, K., Riahi, R., Vera, A., Doukas, A., et al. (2007) Photodynamic inactivation of enterococcus faecalis in dental root canals in vitro. Lasers in Surgery and Medicine, 39, 782-787. doi:10.1002/lsm.20579 [34] Fimple, J., Fontana, C., Foschi, F., Ruggiero, K., Song, X., Pagonis, T., et al. (2008) Photodynamic treatment of endodontic polymicrobial infection in vitro. Journal of Endodontics, 34, 728-734. doi:10.1016/j.joen.2008.03.011
[1] Foschi, F., Cavrini, F., Montebugnoli, L., Stashenko, P., Sambri, V. and Prati, C. (2005) Detection of bacteria in endodontic samples by polymerase chain reaction assays and association with defined clinical signs in Italian patients. Oral Microbiology and Immunology, 20, 289-295. doi:10.1111/j.1399-302X.2005.00227.x [2] Sassone, L., Fidel, R., Faveri, M., Fidel, S., Fiqueiredo, L. and Feres, M. (2008) Microbiological evaluation of primary endodontic infections in teeth with and without sinus tract. International Endodontic Journal, 41, 508-515. doi:10.1111/j.1365-2591.2008.01397.x [3] Gomes, B., Pinheiro, E., Gadê-Neto, C., Sousa, E., Ferraz, C., Zaia, A., et al. (2004) Microbiological examination of infected dental root canals. Oral Microbiology and Immunology, 19, 71-76. doi:10.1046/j.0902-0055.2003.00116.x [4] Gomes, B., Jacinto, R., Pinheiro, E., Sousa, E., Zaia, A., Ferraz, C., et al. (2005) Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia and Prevotella nigrescens in endodontic lesions detected by culture and by PCR. Oral Microbiology and Immunology, 20, 211-215. doi:10.1111/j.1399-302X.2005.00214.x [5] Sousa-Neto, M., Marchesan, M., Pécora, J., Junior, A., Silva-Sousa, Y. and Saquy, P. (2002) Effect of Er:YAG laser on adhesion of root canal sealers. Journal of Endodontics, 28, 185-187. doi:10.1097/00004770-200203000-00010 [6] Schoop, U., Kluger, W., Dervisbegovic, S., Goharkhay, K., Wernisch, J., Georgopoulos, A., et al. (2006) Innovative wavelengths in endodontic treatment. Lasers in Surgery and Medicine, 38, 624-630. doi:10.1002/lsm.20331 [7] Jha, D., Guerrero, A., Ngo, T., Helfer, A. and Hasselgren, G. (2006) Inability of laser and rotary instrumentation to eliminate root canal infection. Journal of the American Dental Association, 137, 67-70. [8] Garcez, A., Ribeiro, M., Tegos, G., Nú?ez, S., Jorge, A. and Hamblin, M. (2007) Antimicrobial photodynamic therapy combined with conventional endodontic treatment to eliminate root canal biofilm infection. Lasers in Surgery and Medicine, 39, 59-66. doi:10.1002/lsm.20415 [9] Blum, J., Michailesco, P. and Abadie, M. (1997) An evaluation of the bactericidal effect of the Nd:YAP laser. Journal of Endodontics, 23, 583-585. doi:10.1016/S0099-2399(06)81127-1 [10] Dostálová, T., Jelínková, H., Housová, D., Sulc, J., Neme?, M., Dusková, J., et al. (2002) Endodontic treatment with application of Er:YAG laser waveguide radiation disinfection. Journal of Clinical Laser Medicine and Surgery, 20, 135-139. doi:10.1089/104454702760090218 [11] Fegan, S. and Steiman, H. (1995) Comparative evaluation of the antibacterial effects of intracanal Nd:YAG laser irradiation: an in vitro study. Journal of Endodontics, 21, 415-417. doi:10.1016/S0099-2399(06)80827-7 [12] Fonseca, M., Júnior, P., Pallota, R., Filho, H., Denardin, O., Rapoport, A., et al. (2008) Photodynamic therapy for root canals infected with Enterococcus faecalis. Photomedicine and Laser Surgery, 26, 209-213. doi:10.1089/pho.2007.2124 [13] Gordon, W., Atabakhsh, V., Meza, F., Doms, A., Nissan, R., Rizoiu, I., et al. (2007) The antimicrobial efficacy of the erbium, chromium:yttrium-scandium-gallium-garnet laser with radial emitting tips on root canal dentin walls infected with Enterococcus faecalis. Journal of the American Dental Association, 138, 992-1002. [14] Gutknecht, N., Nuebler-Moritz, M., Burghardt, S. and Lampert, F. (1997) The efficiency of root canal disinfection using a holmium:yttrium-aluminum-garnet laser in vitro. Journal of Clinical Laser Medicine and Surgery, 15, 75-78. [15] Hardee, M., Miserendino, L., Kos, W. and Walia, H. (1994) Evaluation of the antibacterial effects of intracanal Nd:YAG laser irradiation. Journal of Endodontics, 20, 377-380. doi:10.1016/S0099-2399(06)80294-3 [16] Kreisler, M., Kohnen, W., Beck, M., Al-Haj, H., Christoffers, A., G?tz, H., et al. (2003) Efficacy of NaOCl/H2O2 irrigation and GaAlAs laser in decontamination of root canals in vitro. Lasers in Surgery and Medicine, 32, 189-196. doi:10.1002/lsm.10148 [17] Moritz, A., Gutknecht, N., Goharkhay, K., Schoop, U., Wernisch, J. and Sperr, W. (1997) In vitro irradiation of infected root canals with a diode laser: Results of microbiologic, infrared spectrometric, and stain penetration examinations. Quintessence International, 28, 205-209. [18] Moshonov, J., Orstavik, D., Yamauchi, S., Pettiette, M. and Trope, M. (1995) Nd:YAG laser irradiation in root canal disinfection. Endodontics & dental traumatology, 11, 220-224. doi:10.1111/j.1600-9657.1995.tb00492.x [19] Perin, F., Fran?a, S., Silva-Sousa, Y., Alfredo, E., Saquy, P., Estrela, C., et al. (2004) Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection. Australian Endodontic Journal, 30, 20-22. doi:10.1111/j.1747-4477.2004.tb00162.x [20] Ramsk?ld, L., Fong, C. and Str?mberg, T. (1997) Thermal effects and antibacterial properties of energy levels required to sterilize stained root canals with an Nd:YAG laser. Journal of Endodontics, 23, 96-100. doi:10.1016/S0099-2399(97)80253-1 [21] Schoop, U., Goharkhay, K., Klimscha, J., Zagler, M., Wernisch, J., Georgopoulos, A., et al. (2007) The use of the erbium, chromium:yttrium-scandium-gallium-garnet laser in endodontic treatment: the results of an in vitro study. Journal of the American Dental Association, 138, 949-955. [22] Schoop, U., Moritz, A., Kluger, W., Patruta, S., Goharkhay, K., Sperr, W., et al. (2002) The Er:YAG laser in endodontics: results of an in vitro study. Lasers in Surgery and Medicine, 30, 360-364. doi:10.1002/lsm.10054 [23] Soukos, N., Chen, P., Morris, J., Ruggiero, K., Abernethy, A., Som, S., et al. (2006) Photodynamic therapy for endodontic disinfection. Journal of Endodontics, 32, 979- 984. doi:10.1016/j.joen.2006.04.007 [24] Vezzani, M., Pietro, R., Silva-Sousa, Y., Brugnera-Junior, A. and Sousa-Neto, M. (2006) Disinfection of root canals using Er:YAG laser at different frequencies. Photomedicine and Laser Surgery, 24, 499-502. doi:10.1089/pho.2006.24.499 [25] Folwaczny, M., Mehl, A., Jordan, C. and Hickel, R. (2002) Antibacterial effects of pulsed Nd:YAG laser radiation at different energy settings in root canals. Journal of Endodontics, 28, 24-29. doi:10.1097/00004770-200201000-00006 [26] Bergmans, L., Moisiadis, P., Teughels, W., Van Meerbeek, B., Quirynen, M. and Lambrechts, P. (2006) Bactericidal effect of Nd:YAG laser irradiation on some endodontic pathogens ex vivo. International Endodontic Journal, 39, 547-557. doi:10.1111/j.1365-2591.2006.01115.x [27] Moritz, A., Schoop, U., Goharkhay, K., Jakolitsch, S., Kluger, W., Wernisch, J., et al. (1999) The bactericidal effect of Nd:YAG, Ho:YAG, and Er:YAG laser irradiation in the root canal: An in vitro comparison. Journal of Clinical Laser Medicine and Surgery, 17, 161-164. [28] Mehl, A., Folwaczny, M., Haffner, C. and Hickel, R. (1999) Bactericidal effects of 2.94 μm Er:YAG-laser radiation in dental root canals. Journal of Endodontics, 25, 490-493. doi:10.1016/S0099-2399(99)80288-X [29] Piccolomini, R., D’Arcangelo, C., D’Ercole, S., Catamo, G., Schiaffino, G. and De Fazio, P. (2002) Bacterologic evaluation of the effect of Nd:YAG laser irradiation in experimental infected root canals. Journal of Endodontics, 28, 276-278. doi:10.1097/00004770-200204000-00004 [30] Bergmans, L., Moisiadis, P., Huybrechts, B., Van Meerbeek, B. and Quirynen, M.P.L. (2008) Effect of photo-activated disinfection on endodontic pathogens ex vivo. International Endodontic Journal, 41, 227-239. doi:10.1111/j.1365-2591.2007.01344.x [31] Wang, Q., Zhang, C. and Yin, X. (2007) Evaluation of the bactericidal effect of Er,Cr:YSGG, and Nd:YAG lasers in experimentally infected root canals. Journal of Endodontics, 33, 830-832. doi:10.1016/j.joen.2007.03.017 [32] De Souza, E., Cai, S., Simionato, M. and Lage-Marques, J. (2008) High-power diode laser in the disinfection in depth of the root canal dentin. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology & Endodontics, 106, 68-72. doi:10.1016/j.tripleo.2008.02.032 [33] Foschi, F., Fontana, C., Ruggiero, K., Riahi, R., Vera, A., Doukas, A., et al. (2007) Photodynamic inactivation of enterococcus faecalis in dental root canals in vitro. Lasers in Surgery and Medicine, 39, 782-787. doi:10.1002/lsm.20579 [34] Fimple, J., Fontana, C., Foschi, F., Ruggiero, K., Song, X., Pagonis, T., et al. (2008) Photodynamic treatment of endodontic polymicrobial infection in vitro. Journal of Endodontics, 34, 728-734. doi:10.1016/j.joen.2008.03.011