In 2007 the Australian Dental Association conceded that it is impossible to sterilize a tooth:
“Current medicaments used in association with instrumentation and irrigation are unlikely to predictably achieve a bacteria-free root canal system.
… predictable eradication of bacteria from the root canal still remains an elusive goal…” (my emphasis)
Australian Dental Journal Endodontics Supplement 2007
Another paper from 2006 looked at the use of laser to sterilise a tooth and even that was an abysmal failure.
“Neither the laser nor the rotary instrumentation was able to eliminate endodontic infection.” [i]
A more recent review of endodontic procedures from 2017, compares just about all methods of trying to sterilize a tooth and still comes up with the fact that they cannot achieve this goal.[ii]
Bacteria remaining in a tooth multiply rapidly, and escape from the tooth and enter the rest of the body. Sadly endodontists do not advise their patients of this?
The latest & the Greatest
Ozone and Laser Cleaning Techniques
In the last 10 years there has been an increased use of Ozone and Laser to attempt to sterilize the canal. These are certainly innovative, and they actually do kill bacteria and other microorganisms when suitably exposed. I truly admire the dentists who have invested many thousands of dollars to purchase the necessary equipment in an attempt to treat their patients with the most up to date methods, to try and achieve success. Sadly, the research shows that Ozone will only penetrate the dentine tubules to a depth of 300 microns or a third of a millimeter. Laser is better but it can only go about ½ mm into the dentine.[iii] There are a couple of articles that claim a bacterial reduction to a depth of a whole 1 mm into the dentine which is further than any other method I have come across. [iv],[v],
No one dares to talk about the other 2 – 3 mm of dentine that is left untouched and therefore contaminated.
Sadly, neither of these new wonder wands will sterilize the tooth!
Much of the research has also suggested that laser is about equal to sodium hypochlorite in reducing the bacterial load. In other words, it is no better than the old tried, tested and failed methods of attempting sterilization of the canal system. In fact, they go on to say that:
“there is insufficient evidence to suggest that any specific laser is superior to the traditional endodontic treatment.” [vi]
Irrigation with old fashioned Sodium Hypochlorite (NaOCl) shows similar results to using laser. [vii],[viii],[ix] I might say that this is great confirmation for how to treat soiled nappies. Keeping your baby healthy with Sodium Hypochlorite for the nappy wash certainly can work. Another study showed that Chlorhexidine was significantly more effective to kill bacteria than laser [x] Similar studies have shown a great reduction in the bacterial count in narrow sections of dentine but still they demonstrate that the bacteria were not eliminated 100%. The canals were not sterile. [xi],[xii],[xiii],[xiv],[xv],[xvi],[xvii],[xviii],[xix]
It is also worth mentioning that there have been several adverse effects from the use of laser in dentistry, such as histopathological changes, and infection transmission due to laser smoke. Lasers can crack the root of a tooth!
“During dental procedures, necrosis of the pulp, periodontal ligament and odontoblasts, cemental lysis, bone resorption, hypo/hyperpigmentation, burns, itching, and scarring might occur. In addition, laser can weaken the dentin by inducing surface cracks.”[xx]
There is NO known way of sterilizing a tooth aside from autoclaving or boiling it for 30 minutes. Neither have a high patient acceptance.
[i] Jha D Guerrero A Ngo T Helfer A Hasselgren G
Inability of laser and rotary instrumentation to eliminate root canal infection. J Am Dent Assoc (2006 Jan) 137(1):67-70
[ii] Recent Advances in Root Canal Disinfection: A Review Zahed Mohammadi, et al Iran Endod J. 2017 Fall; 12(4): 402–406.
[iii] Kreisler M, Kohnen W, Beck M, Al Haj H, Christoffers AB, Gotz H, et al. Efficacy of NaOCI/H2O2 irrigation and GaAlAs laser in decontamination of root canals in vitro. Lasers Surg Med 2003;32:189-96
[iv] Bergmans L, Moisiadis P, Teughels W, Van Meerbeek B, Quirynen M, Lambrechts P. Bactericidal effect of Nd:YAG laser irradiation on some endodontic pathogens ex vivo. Int Endod J 2006;39:547-57.
[v] Klinke T, Klimm W, Gutknecht N. Antibacterial effects of Nd:YAG laser irradiation within root canal dentin. J Clin Laser Med Surg 1997;15(1):29-31.
[vi] The Use of Lasers in Disinfection and Cleanliness of Root Canals: a Review
Ivona Bago Jurič and Ivica Anić Acta Stomatol Croat. 2014 Mar; 48(1): 6–15.
[vii] The Disinfecting Efficacy of Root Canals with Laser Photodynamic Therapy
Aliu Xhevdet, et al J Lasers Med Sci. 2014 Winter; 5(1): 19–26.
[viii] . Piccolomini R, D›Arcangelo C, D›Ercole S, Catamo G, Schiafino G, De Fazio P. Bacteriologic evaluation of the effect of Nd:YAG laser irradiation in experimental infected root canals. J Endod 2002;28(4):276-8.
[ix] Meire MA, De Prijck K, Coenye T, Nelis HJ, De Moor RJ. Effectiveness of different laser systems to kill Enterococcus faecalis in aqueous suspension and in an infected tooth model. Int Endod J 2009;42,351-9.
[x] Kangarloo A, Fekrazad R, Salar O. Antibacterial effect of Er,Cr: YSGG laser and 2%chlorhexidine solution on dental tubules infected by E. faecalis. Thesis No:2519- 2004.
[xi] Moritz A, Jakolitsch S, Goharkhay K, Schoop U, Kluger W, Mallinger R, et al. Morphologic changes correlating to different sensitivities of Escherichia coli and Entrococcus faecalis to Nd:YAG laser irradiation through dentin. Lasers Surg Med 2000;26:250-61.
[xii] Le Goff A, Dautel-Morazin A, Guigand M, Vulcain JM, Canal Disinfection by Laser during Root Canal Therapy 16 Journal of Lasers in Medical Sciences Volume 4 Number 1 Winter 2013 Bonnaure-Mallet M. An evaluation of the CO2 laser for endodontic disinfection. J Endod 25(2):105-8.
[xiii] Gutknecht N, Van Gogswaardt D, Conrads G, Apel C, Schubert C, Lampert F. Diode laser radiation and its bactericidal effect in root canal wall dentin. J Clin Laser Med Surg 2000;18(2):57-60.
[xiv] De Sauza EB, Cai S, Simionato MR, Lage-Marques JL. High power diode laser in the disinfection in depth of the root canal dentin
[xv] Vezzani MS, Pietro R, Silva-Sousa YT, Brugnera-Junior A, Sousa-Neto MD. Disinfection of root canals using Er: YAG laser at different frequencies. Photomed Laser Surg 2006; 24(4):499-502.
[xvi] Godon W, Atabakhsh VA, Meza F, Doms A, Nissan R, Rizoiu I, et al. 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. J Am Dent Assoc; 138(7):992-1002.
[xvii] Moritz A, Schoop U, Goharkhay K, Jakolitsch S, Kluger W, Wernisch J, et al. The bactericidal effect of Nd:YAG, Ho:YAG, and Er:YAG laser irradiation in the root canal: an in vitro co
[xviii] Foschi F, Fontana CR, Ruggiero K, Riahi R, Vera A, Doukas AG, et al. Photodynamic inactivation of Enterococcus faecalis in dental root canals in vitro. Lasers Surg Med 2007;39(10):782-7.
[xix] Fimple JL, Fontana CR, Foschi F, Ruggiero K, Song X, Pagonis TC, et al. Photodynamic treatment of endodontic polymicrobial infection in vitro. J Endod 2008;34(6):728- 34.
[xx] Lasers in Dentistry: Is It Really Safe? Hamed Mortazavi 2016 Volume : 7 Issue : 4 Page : 123-127