Open Journal of Stomatology, 2011, 1, 126-139
doi:10.4236/ojst.2011.14020 Published Online December 2011 (http://www.SciRP.org/journal/ojst/
OJST
).
Published Online December 2011 in SciRes. http://www.scirp.org/journal/OJST
Which treatment protocol, among classical methods and/or
various laser applications is the most effective in root canal
disinfection, in vitro? A systematic review
Joanna Theodosopoulou1, Alexandra Tsigarida2, Konstantinos Chochlidakis3
1Harvard School of Dental Medicine (HSDM), The Forsyth Institute, Private Practice, Athens, Greece;
2Department of Periodontology, The Ohio State University, Columbus, USA;
3Department of Prosthodontics, Eastman Institute for Oral Health, Rochester, USA.
Received 20 July 2011; revised 11 October 2011; accepted 26 October 2011.
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 = 1.636) seemed
to be the best method. In P. aeruginosa and in A.
naeslundii elimination, instrumentation of the root
canal followed by irrigation with 5.5% 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 irradi ation (logCFU/ml = 1.924) 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. aeru ginosa 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.
Keywords: Lasers; Classical Methods; Endodontic; Root
Canal Therapy; Dentin; Bacteria; Disinfection
1. INTRODUCTION
One of the most crucial and fundamental stages of endo-
dontic therapy is the root canal disinfection in its three-
dimensional network of dentinal tubules. Nevertheless,
persistence of infection in the root canal is responsible
for long-term failures and need for endodontic therapy
retreatments.
It is generally accepted that microorganisms tend to
remain in the root canal even after proper preparation
and are responsible for flare-ups, after the completion of
the endodontic therapy. The most common of these mi-
croorganisms are: Fusobacterium nucleatum, Enterococ-
cus faecalis, Prevotella intermedia, Streptococcus angi-
nosa, Treponima denticolla, Porphyromonas gingivalis
[1-4].
During the last years, laser irradiation has been addi-
tionally introduced in root canal preparation, trying to
gain acceptance for its disinfection ability in comparison
with the common mechanical instrumentation and irriga-
tion procedures.
Many studies examine the effectiveness of Nd:YAG,
diode, Er,Cr:YSGG and Er:YAG laser, when used in dif-
ferent wavelengths, solely, or in addition with various so-
lutions in the bacterial elimination inside the root canals.
The purpose of this systematic review was to answer the
question “Which treatment protocol, among classical me-
thods and/or various laser applications is the most ef-
fective in root canal disinfection, in vitro”.

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 127
2. MATERIALS AND METHODS
2.1. Literature Search
One electronic search of MEDLINE from 1966 to June
2010 (Table 1), one Cochrane (Table 2) and one Embase
search from 1945 to June 2010 (Table 3) were con-
ducted.
Table 1. Medline search strategy.
# Search history Results
#13 Search #12 Limits: Humans, English, French,
German, Greek, Modern 240
#12 Search #1 1 AND #1 282
#12 Search #11 AND #1 13,136
#11 Search #7 AND #10 15,641
#10 Search #8 OR #9 14,900
#9 Search (root canal therapy) 1622
#8 Search (endodontically treated teeth) 4,830,685
#7 Search #1 OR #2 OR #3 OR #4 OR #5 OR #6 138,039
#6 Search (tooth OR teeth) 1,267,279
#5 Search bacteria 3,639,649
#4 Search method 19,546
#3 Search dentin 14,477
#2 Search endodont* 137,179
#1 Search laser 240
Table 2. Cochrane search strategy.
# Search history Results
#1 Laser 6294
#2 Endodont* 1174
#3 Dentin 1427
#4 Method 241,235
#5 Bacteria 4978
#6 (Tooth OR teeth) 7062
#7 (#1 OR #2 OR #3 OR #4 OR #5 OR #6) 248,592
#8 (Endodontically treated teeth) 89
#9 (Root canal therapy) 401
#10 (#8 OR #9) 442
#11 (#7 AND #10) 422
#12 (#1 AND #11) 28
Table 3. Embase search strategy.
# Search history Results
1 Laser 106,390
2 Endodont* 1076
3 Dentin 2983
4 Method 785,208
5 Bacteria 121,213
6 (Tooth OR teeth) 40,114
7 (#1 OR #2 OR #3 OR #4 OR #5 OR #6) 5,138,833
8 (Endodontically treated teeth) 43
9 (Root canal therapy) 64
10 (#8 OR #9) 1,426,192
11 (#7 AND #10) 218,687
12 (#1 AND #11) 225,630
13 Limit 12 to humans, English or French or German
or Greek from “1945-2007” 35
2.2. Inclusion Criteria-Validity
Three independent reviewers examined all the identified
abstracts to determine whether they met the following
criteria:
1) Study in vitro.
2) Conducted in human teeth.
3) Related to the question.
4) Experimental and control group.
5) Quantitative results provided.
6) English, German, French languages.
Whenever it was not possible to make this determina-
tion, the article was examined in full text. Subsequently,
all relevant articles were obtained and a determination
whether or not they met the inclusion criteria was made
by three reviewers. It is important to state that only stu-
dies measuring the bactericidal effect of lasers and other
procedures were included. The studies that examined the
removal of smear layer or debris, the morphological or
histological changes, the apical leakage after obturation
and the dentin permeability were excluded, as irrelevant
to our question (Tables 8-12).
All articles that met the inclusion criteria were as-
sessed for validity. Validity was determined on a 7-point
scale (Table 4) and studies not meeting 5 or more of the
7 validity criteria were excluded.
All articles were classified by evidence level (Table 5)
(EBM://cebm.jr2.ox.uk /docs/levels.html) and then asses-
sed for Validity (http://www.cebm.utoronto.ca/teach/ma-
terials/therapy.htm) (Table 6).
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 128
Table 4. Validity assessment criteria1.
1. Was the assignment of patients of treatment randomised?
2. Was the randomisation list concealed?
3. Was the follow-up of patients sufficiently long and complete?
4. Were all patients analysed in the groups to which they were
randomised?
5. Were patients and clinicians blinded to the treatment being re-
ceived?
6. Aside from the experimental treatment, were the groups treated
equally?
7. Were the groups similar at the start of the trial?
Table 5. Clinical evidence levels2.
Level of evidence Study Type #
1A Randomized control trial (RCT)
Systematic Review of RCTs 6
1B Controlled Trial Systematic review of CCTs2
2 Cohort Study(CCS) Systematic review of CSs2
3 Case Control Study Systematic Review of CCSs0
4 Case Series 0
5 Expert’s Opinion Narrative Review 0
NA3 Cross Sectional Case Reports
Animal Studies Laboratory Studies 0
Non validated Because of language limitations 0
Table 6. Validity assessment criteria application.
Reference 1 2 3 4 5 6 7
De Souza, E. B. et al., 2008 Y Y Y Y N Y Y
Fimple, J. L. et al., 2008 Y Y Y Y N Y Y
Fonseca, M. B. et al., 2008 N N Y Y N Y Y
Bergmans, L. et al., 20084 Y Y Y Y N Y Y
Foschi, F. et al., 2007 Y Y Y Y N Y Y
Wang, Q. Q. et al., 20074 Y Y Y Y N Y Y
Gordon, W. et al., 2007 N N Y Y N Y Y
Schoop, U. et al., 2007 N N Y Y N Y Y
Soukos, N. S. et al., 2006 N N Y Y N Y Y
Vezzani, M. S. et al., 2006 N N Y Y N Y Y
Bergmans, L. et al., 20064 Y Y Y Y N Y Y
Perin, F. M. et al., 2004 N N Y Y N Y Y
Kreisler, M. et al., 2003 N N Y Y N Y Y
Dostαlovα, T. et al., 2002 N N Y Y N Y Y
Schoop, U. et al., 2002 N N Y Y N Y Y
Piccolomini, R. et al., 20024 Y Y Y Y N Y Y
Folwaczny, M. et al., 20024 Y Y Y Y N Y Y
Moritz, A. et al., 1999 Y Y Y Y N Y Y
Mehl, A. et al., 1999 Y Y Y Y N Y Y
Moritz, A. et al., 1997 N N Y Y N Y Y
Ramskold, L. O. et al., 1997 N N Y Y N Y Y
Gutknecht, N. et al., 1997 N N Y Y N Y Y
Moshonov, J. et al., 1995 N N Y Y N Y Y
Fegan, S. E. et al., 1995 N N Y Y N Y Y
Hardee, M. W. et al., 1994 N N Y Y N Y Y
2.3. Data Analysis
All results were converted and finally expressed in log-
CFU/ml (logarithm of the Colony Forming Units per
milliliter) of the bacteria that were found after root canal
preparation and laser or not laser irradiation. This was
done for all specimens of all the studies.
Data from the studies that met validity criteria were ex-
tracted and classified by the method used for each bac-
terial group (Tables 15-21), for the polymicrobial stud-
ies (Ta b l e 22 ) and for all of the studies together (Table
23).
3. RESULTS
3.1. Medline Search
The MEDLINE search from 1966 to June 2010 identi-
fied 240 articles (Table 7). From 240 articles identified by
the search, the hand examination of titles, abstracts and
articles in full text revealed that 120 were irrelevant and
120 appeared to be relevant. Of the 120 relevant articles,
6 were in vivo studies, 5 expert’s opinion, 6 narrative
reviews, 3 case reports, 1 was an animal study and the
remaining 99 were relevant in vitro studies.
Of the 99 relevant in vitro studies:
 Seventy were excluded because they were not
related to the question.
Analytically:
Seventeen examined the removal of smear layer
and debris (Table 8).
Twenty four examined morphological changes of
the root canal (Table 9).
Twelve examined obturation and apical leakage
after obturation (Table 10). Eleven examined den-
tin permeability (Table 11).
Five examined the thermal effects on the dentin
(Table 12).
One examined adhesion of root canal sealers [5].
 One was excluded because it was not conducted on
human teeth but on human teeth slices [6].
 Three were excluded because they did not provide
quantitative results [7-9].
From the remaining 25 articles, 15 [10-24] were ex-
cluded because they met less than 5 of 7 validity criteria
(Table 13). Ten articles [25-34] were finally included. De-
tails of the included 10 studies are presented in Table 14.
3.2. Cochrane Search
The Cochrane search identified 28 articles. From these 28
articles the hand examination of titles, abstracts and arti-
cles in full text, revealed that 16 were irrelevant to the
question and 12 appeared to be relevant. Of the 12 arti-
cles, 7 did not meet the inclusion criteria and the remai-
ning 5 were relevant in vitro studies. All of the 5 relevant
in vitro studies were also identified by the Medline
1Evidence-Based Medicine. How to Practise and Teach EBM, 2nd
edition, Sackett, D. et al., Churchill Livingstone, Edinburgh, UK.
2http://www.cebm.net/index.aspx?o=1025
3Not applicable.
4Also identified in Cochrane search.
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 129
Table 7. Search results.
MEDLINE COCHRANE EMBASE
(n = 240) (n = 28) (n = 35)
Irrelevant (n= 120)(n=16)(n=35)
Relevant studies
(n = 120) (n = 12) (n = 0)
In Vitro studies
(n = 99) (n = 13) (n = 0)
Meeting the Inclusion and Validity Criteria
(n = 10) (n = 5) (n = 0)
In Vivo (n = 6)(n = 0) (n = 0)
Expert’s opinion (n = 5)(n = 0) (n = 0)
Narrative reviews(n = 6)(n = 0) (n = 0)
Case reports (n = 3)(n = 0) (n = 0)
In animals (n = 1)(n = 0) (n = 0)
Not Found (n = 0)(n = 0) (n = 0)
Not meeting the
Inclusion Criteria
(n = 74)(n = 7)(n = 0)
Not meeting the
Validity Criteria
(n = 15)(n = 0)(n = 0)
Table 8. Excluded studies: remove smear layer/debris.
Reference Detail
Soares F. et al., 2008 Remove smear layer
Moshonov J. et al., 2004 Remove smear layer
Moshonov J. et al., 2003 Remove smear layer
Matsuoka E. et al., 1998 Remove smear layer
Takeda F. H. et al., 1998 Remove smear layer
Arrastia-Jitosho A. M. et al., 1998 Remove smear layer
Takeda F. H. et al., 1998 Remove smear layer
Radatti D. A. et al., 2006 Remove debris
Blum J. Y. et al., 1997 Remove debris
Harashima T. et al., 1997 Remove debris
Saunders W. P. et al., 1995 Remove debris
Machida T. et al. , 1995 Remove debris, Thermal effects
Moshonov J. et al., 1995 Remove debris
Bahcall J. K. et al., 1993 Remove debris, Morphological
Frentzen M. et al., 1991 Remove debris
Liesenhoff T. et al., 1989 Remove debris, Morphological
Pini R. et al., 1989 Remove debris
search, met all the inclusion criteria and 5 or more of the
validity assessment criteria. So, they were finally inc-
luded (Table 6).
3.3. Embase Search
The Embase search from 1945 to June 2010 identified
35 articles. From these 35 articles identified by the sear-
ch, the hand examination of titles, abstracts and articles
in full text, revealed that all of them were irrelevant.
In order to be able to compare the bactericidal ability
of the various treatment protocols that were applied on
the human teeth in vitro, by each different group of re-
searchers, the results were expressed in logCFU/ml. The
CFU/ml of the bacteria that were found in the root canals
after bacterial contamination and consecutive standard
root canal preparation and/or laser irradiation was cal-
culated and converted in logCFU/ml. The closer the
value of logCFU/ml is to 0, the greater the positive ef-
fect the treatment protocol has to the root canal disin-
fecttion.
LogCFU/ml of all bacteria is plotted in Ta b l e s 1 5 - 2 3
(Clustered bars and 3-D clustered bars). On the X-axis
lies the logCFU/ml and on the Y-axis the various treat-
ment protocols.
OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 130
Table 9. Excluded articles: morphological changes.
Reference Details
Gurbuz, T. et al., 2008 Morphological study
Da Costa Ribeiro, A. et al., 2007 Morphological, Thermal effects
Jahan, K. M. et al., 2006 Morphological
Altundasar, E. et al., 2006 Morphological and
Histochemical Changes
Matsuoka, E. et al., 2005 Morphological study
Biedma, B. M. et al., 2005 Morphological study
Camargo, S. E. et al., 2005 Morphological study
Niccoli-Filho, W. et al., 2005 Morphological study
Ali, M. N. et al., 2005 Morphological study,
Smear layer removal
Ishizaki, N. T. et al., 2004 Morphological, Thermal effects
Khabbaz, M. G. et al., 2004 Morphological study
Kesler, G. et al., 2002 Morphological study,
Remove smear layer
Kaitsas, V. et al., 2001 Morphological and
Histological changes
Matsuoka, E. et al., 2000 Morphological study
Yamazaki, R. et al., 2001 Morphological, Thermal effects
Barbakow, F. et al., 1999 Morphological study,
Remove smear layer
Takeda, F. H. et al., 1999 Morphological study,
Remove smear layer
Eto, J. N. et al., 1999 Morphological study,
Remove smear layer
Takeda, F. H. et al., 1998 Morphological study,
Remove smear layer
Harashima, T. et al., 1998 Morphological study,
Remove smear layer
Khan, M. A. et al., 1997 Morphological, Thermal effects
Komori, T. et al., 1997 Morphological, Thermal effects
Goodis, H. E. et al., 1993 Morphological study,
Remove smear layer
Gutknecht, N., Behrens, V. G. 1991 Morphological study
Table 10. Excluded articles: obturation/apical leakage.
Reference Details
Ebihara A. et al., 2002 Apical leakage after obturation
Kimura Y. et al., 1999 Apical leakage after obturation
Kimura Y. et al., 2001 Apical leakage after obturation
Park D. S. et al., 2001 Apical leakage after obturation
Goya C. et al., 2000 Apical leakage after obturation,
Removal of smear layer
Yamazaki R. et al., 1999 Apical leakage after obturation
De Moura-Netto C. et al., 2007 Apical sealing
Gekelman D. et al., 2002 Apical sealing of root canal fillings
Carvalho C. A. et al., 2002 Apical sealing of root canal fillings.
Varella C. H., Pillegi R., 2007 Obturation
Gharib S. R. et al., 2007 Obturation
Wang X. et al., 2005 Obturation, Morphological,
Thermal effects, Apical leakage
Table 11. Excluded articles: dentin permeability.
Reference Details
Winik, R. et al., 2006 Marginal permeability, Tubular penetration,
Al-Azzawi, L. M. et al., 2006Dentin permeability
Aranha, A. C. et al., 2005Dentin permeability
Oliveira, R. G. et al., 2004Dentin permeability after apicoectomy
Gouw-Soares, S. et al., 2004Dentin permeability
Arisu, H. D. et al., 2004Dentin permeability, Morphological
Brugnera, A. Jr. et al., 2003Dentin permeability
Lee, B. S. et al., 2002 Dentin permeability
Pecora, J. D. et al., 2000Dentin permeability
Stabholz, A. et al., 1992Dentin permeability
De Souza, F. D. et al., 2005Coronal microleakage
Table 12. Excluded articles: thermal effects/adhesion of root
canal sealers
Reference Details
Nammour S. et al., 2004 Thermal effects
Deutsch A. S. et al., 2004 Thermal effects
Amyra T. et al., 2000 Thermal effects, Morphological
Cohen B. I. et al., 1996 Thermal effects
Neev J. et al., 1993 Thermal effects
Table 13. Excluded studies: not meeting validity criteria.
Reference 1 2 3 4 567
Fonseca, M. B. et al., 2008N N Y Y N Y Y
Gordon, W. et al., 2007 N N Y Y N Y Y
Schoop, U. et al., 2007 N N Y Y N Y Y
Soukos, N. S. et al., 2006 N N Y Y N Y Y
Vezzani, M. S. et al., 2006N N Y Y N Y Y
Perin, F. M. et al., 2004 N N Y Y N Y Y
Kreisler, M. et al., 2003 N N Y Y N Y Y
Dostαlovα, T. et al., 2002 N N Y Y N Y Y
Schoop, U. et al., 2002 N N Y Y N Y Y
Moritz, A. et al., 1997 N N Y Y N Y Y
Ramskold, L. O. et al., 1997N N Y Y N Y Y
Gutknecht, N. et al., 1997 N N Y Y N Y Y
Moshonov, J. et al., 1995 N N Y Y N Y Y
Fegan, S. E. et al., 1995 N N Y Y N Y Y
Hardee, M. W. et al., 1994N N Y Y N Y Y
A) Analysis of the Results of Studies with Specific
Bacteria
 Enterococcus faec alis
Enterococcus faecalis survival was examined 19 times
by 5 different groups of researchers.
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 131
OJST
Table 14. Analysis of treatment protocols.
REFERENCES/
BACTERIA STORAGE MATERIAL IRRIGATION SOLUTION INSTRUMENTATIONLASER DURATION
NUMBER
OF T EETH
De Souza E. B. et
al. (2008).
E. faecalis
(3*108 cells/ml)
1% NaOCl
G1, G2:
0.5% NaOCl + urea
peroxide cream +
17% EDTA-T +
saline solution G3:
Saline solution
G1, G2,: Rotary
instrumentation
(Crown down), No 50.
G1: diode laser (830 nm/3 W)
G2: no laser irradiation
G3: no laser irradiation
(control)
2 days
N = 30
G1 = 10
G2 = 10
G3 = 10
Fimple J. L. et al.
(2008)
A. israelii
(2.5*108 cells/ml)
F. nucleatum
(2.5*108 cells/ml)
P. gingivalis
(2.5*108 cells/ml)
P. intermedia
(2.5*108 cells/ml)
0.5% NaOCl for
2 - 4
weeks.
G1 - G4:
RcPrep +
6% NaOCl +
17% EDTA +
6% NaOCl
G1 - G4:
Rotary instrumentation
(Crown-down)
MAF: 0.465
First set of experiments
(n = 72, BHI broth):
G1: No laser/No MB
G2: MB only
G3: Diode laser
(665 nm/1 W)
G4: Diode laser (665 nm/1 W)
and MB
Second set of experiments
(n = 39, PBS broth):
G1: No laser/No MB
G2: MB only
G3: Diode laser
(665 nm/1 W) and MB
7 days
First set of
experiments
(n = 72):
G1 = 19
G2 = 18
G3 = 17
G4 = 18
Second set of
experiments
(n = 39):
G1 = 13
G2 = 13
G3 = 13
Bergmans L. et al.
(2008)
S. anginosus
(4*108 cells/ml)
0.5% chloramine
in water at
4˚C
Ga - Gd:
2.5% NaOCl +
17% EDTA + tap
water
Ga - Gd:
Rotary instrumentation
(Crown down), No 30.
Ga: diode laser(635 nm/0.1 W) +
TBO + RTF
Gb: diode laser(635 nm/0.1 W) +
RTF
Gc: TBO + RTF
Gd: RTF (positive control)
2 days
N = 12
Ga = 3
Gb = 3
Gc = 3
Gd = 3
E. faecalis:
(4*108 cells/ml)
0.5% chloramine
in water at
4˚C
Ga - Gd:
2.5% NaOCl +
17% EDTA + tap
water
Ga - Gd:
Rotary instrumentation
(Crown down), No 30.
Ga: diode laser (635 nm/0.1 W)
+ TBO + RTF
Gb: diode laser (635 nm/0.1 W)
+ RTF
Gc: TBO + RTF
Gd: RTF (positive control)
2 days
N = 12
Ga = 3
Gb = 3
Gc = 3
Gd = 3
F. nucleatum
(4*108 cells/ml)
0.5% chloramine
in water at
4˚C.
Ga - Gd:
2.5% NaOCl +
17% EDTA + tap
water
Ga - Gd:
Rotary instrumentation
(Crown down), No 30.
Ga: diode laser (635 nm/0.1 W)
+ TBO + RTF
Gb: diode laser (635 nm/0.1 W)
+ RTF
Gc: TBO + RTF
Gd: RTF (positive control)
2 days
N = 12
Ga = 3
Gb = 3
Gc = 3
Gd = 3
Negative group
(uninfected)
0.5% chloramine
in water at
4˚C
Ga - Gd:
2.5% NaOCl +
17% EDTA + tap
water
Ga - Gd:
Rotary instrumentation
(Crown down), No 30.
No laser 2 days N = 2
Foschi F., et al.
(2007)
E. faecalis
(5*108 cells)
0.5% NaOCl for
2 weeks.
G1 - G4
6% NaOCl:
17% EDTA
deactivated with
6% NaOCl for 3
min.
G1 - G4
Rotary instrumentation
(Crown down),
MAF: 0.465
G1: no laser/no MB
G2: MB
G3: Diode laser (665 nm/1 W)
G4: Diode laser (665 nm/1 W)
and MB
6 days
N = 64
G1 = 15
G2 = 15
G3 = 15
G4 = 15
Wang Q. et al.
(2007)
E. faecalis
(>108 CFU/ml)
physiological
saline solution at
4˚C
G1 - G4:
5.25% NaOCl+
physiological saline
G5:
2.5% NaOCl +
5.25% NaHS +
physiological saline
G6:
None
G1 - G6:
Hand instrumentation
(step-back), No 50
G1: Er,Cr:YSGG (2780 nm/1 W)
G2: Er,Cr:YSGG (2780 nm/1.5 W)
G3: Nd:YAG (1064 nm/1 W)
G4: Nd:YAG (1064 nm/1.5W)
G5: no laser irradiation
(positive control)
G6: no laser irradiation
(negative control)
1 day
N = 60
G1 = 10
G2 = 10
G3 = 10
G 4 = 10
G5 = 10
G6 = 10

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 132
Bergmans L., et al.
(2006)
E. faecalis
(4*10 8 CFU/ml)
0.5% chloramine
in water
at 4˚C
G1, G2:
2.5% NaOCl+
17% EDTA+
tap water + 0.9%
sterile saline
G3:
2.5% NaOCl +
17% EDTA+
tap water
G1 - G3:
Rotary instrumentation
(Crown down), No 30
G1: Nd:YAG laser
(1064 nm/1.5 W/15 Hz) + RTF
G2: RTF, no laser irradiation,
Infected (positive control)
G3: RTF, no laser irradiation,
(uninfected, negative control)
2 days
N = 8
G1 = 3
G2 = 3
G3 = 2
Piccolomini R., et
al. (2002)
A. naeslundii
(1.8* 108 CFU/ml)
none
SubA, SubB1,
SubB2
Physiological
saline + EDTA
SubC:
physiological
saline +
EDTA +
5.25% NaOCl
All groups:
Hand instrumentation
(Crown-down).
SubA: no laser irradiation
(control)
SubB1: Nd:YAG laser
(1064 nm/5 Hz)
Sub B2: Nd:YAG laser
(1064 nm/10 Hz)
SubC: no laser irradiation
1 day.
N = 60
SubA = 5
SubB1 = 10
SubB2 = 10
SubC = 5
P. aeruginosa
(1.8* 108 CFU/ml) none
SubA, SubB1,
SubB2
Physiological
saline + EDTA
SubC:
physiological
saline+
EDTA+
5.25% NaOCl
All groups:
Hand instrumentation
(Crown-down).
SubA: no laser irradiation
(control)
SubB1:Nd:YAG laser
(1064 nm/5 Hz)
Sub B2: Nd:YAG laser
(1064 nm/10 Hz)
SubC: no laser irradiation
1 day.
SubA = 5
SubB1 = 10
SubB2 = 10
SubC = 5
Folwaczny M., et
al. (2002)
Escherichia Coli
(8.67*106
CFU/ml)
Sterile saline
solution
G1a-G1d: saline
solution
G1d;
saline solution+
1% NaOCl
G1a - G1d:
Hand instrumentation,
No 40.
G1a:No laser irradiation
(positive control)
G1b: Nd:YAG laser
(1064 nm/0.005 W)
G1c: Nd:YAG laser
(1064 nm/0.01 W)
G1d: No laser irradiation
1 day
N = 114
G1a = 13
G1b = 13
G1c = 13
G1d = 13
Folwaczny M., et
al. (2002)
S. aureus
(1.44*106 CFU/ml)
Sterile saline
solution
G2a - G2d: saline
solution
G2d;
saline solution+
1% NaOCl
G2a-G2d:
Hand instrumentation,
No 40.
G2a:No laser irradiation
(positive control)
G2b: Nd:YAG laser
(1064 nm /0.005 W)
G2c: Nd:YAG laser
(1064 nm/ 0.01 W)
G2d: No laser irradiation
1 day
G2a = 13
G2b = 13
G2c = 13
G2d = 13
Negative control
(uninfected)
Sterile saline
solution saline solution Hand instrumentation, No 40.
G3: no laser irradiation
(negative control) 1 day G3 = 10
Moritz A., et al.
(1999)
Escherichia coli
and
Enterococcus fae-
calis
( 5*105 CFU/mL)
Physiological
saline solution
All groups:
EDTA+ physio-
logical saline
solution
All groups:
Rotary instrumentation,
(Step-back)
G1: Positive control (untreated)
G2: Nd:YAG laser
(0.8 W/1064 nm)
G3: Nd:YAG laser
(1.5 W/1064 nm)
G4: Ho: YAG laser
(0.8 W/2130 nm)
G5: Ho:YAG laser,
(1.5 W/2130 nm)
G6: Er:YAG laser,
(0.8 W/2940 nm)
G7: Er:YAG laser,
(1.5 W/2940 nm)
1 day
N = 40
G1: 10
G2: 5
G3: 5
G4: 5
G5: 5
G6: 5
G7: 5
Mehl A., et al.
(1999)
Escherichia coli
(1.1*106 CFU/ml)
none
Ge1-Ge4: sterile
saline solution
Ge4:
1.25%
NaOCl
Hand instrumentation,
No 40.
Gs1: no laser irradiation
(positive control)
Gs2: Er:YAG
(2940 nm/0.003 W/15 sec/50 mJ)
Gs3: Er:YAG
(2940 nm/0.001 W/60 sec/50 mJ)
Gs4: no laser irradiation
(1.25% NaOCl )
1 day
N = 90
Ge1: 10
Ge2: 10
Ge3: 10
Ge4: 10
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 133
S. aureus
(1.53*106 CFU/ml) none
Gs1-Gs4: sterile
saline solution
Gs4:
1.25% NaOCl
Hand instrumentation,
No 40.
Gs1:no laser irradiation
(positive control)
Gs2: Er:YAG
(2940 nm/0.003 W/15 sec/50 mJ)
Gs3:Er:YAG
(2940 nm/0.001 W/60 sec/50 mJ)
Gs4: no laser irradiation
(1.25% NaOCl )
1 day
Gs1: 10
Gs2: 10
Gs3: 10
Gs4: 10
Negative control
(uninfected) none None
Hand instrumentation,
No 40.
Gn: negative
(uninfected) 1 day Gn: 10
Table 15. Enterococcus faecalis survival. Table 18. Escheric h ia co l i survival.
Table 19. Actinomyces naeslundii survival.
Table 16. Streptococcus anginosus survival.
Table 20. Staphylococcus aureus survival.
Table 17. Fusobacterium nucleatum survival.
Table 21. Pseudomonas aeruginosa survival.
Piccolomini R. et al(2002)
In the first place, they contaminated the root canals
with E. faecalis. In the second place they performed
chemo-mechanical preparation and/or laser irradiation
with or without specific solutions. The logCFU/ml ran-
ges from 1.636 to 8.818 (Table 15).
The best treatment protocols for root canal disinfect-
tion in descending order are as follows:
Instrumentation of the root canal and diode laser/665
nanometer/1 Watt irradiation with the combined effect
OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 134
Table 22. Polymicrobial survival.
Table 23. Mean microbial survival.
of Methylene Blue (MB) as photosensitizing agent (log-
CFU/ml = 1.636) [33].
Instrumentation of the root canal and diode laser/665
nm/1 W irradiation
(logCFU/ml = 2.061) [33].
Instrumentation of the root canal combined with MB
as photosensitizing agent (logCFU/ml = 2.190) [33].
Instrumentation followed by irrigation with 2.5%
NaOCl (sodium hypochloride)
(logCFU/ml = 2.602) [31].
When instrumentation and diode laser/830 nm/3 W
were used, no CFU/ml was found. However, as the au-
thor explained, this result is due to the fact that the level
of sensitivity of the methodology used, was insufficient
for detecting viable cells in low concentrations (contact
with the author via e-mail) [32].
 Streptococc u s an gi nosus
Streptococcus anginosus survival was examined 4 ti-
mes by 1 group of researchers. In the first place they per-
formed chemo-mechanical preparation and in the second
place they contaminated the root canals with S. angino-
sus. Consequently, they completed root canal preparation
and either used or not laser irradiation with specific so-
lutions. The logCFU/ml ranges from 5.000 to 6.204 (Ta-
ble 16) [30].
These results demonstrate no satisfying reduction of S.
anginosus after diode laser/635 nm/0.1 W irradiation
combined with RTF (reduced transferred fluid) and/or
TBO (toluidine blue), nor after instrumentation and irri-
gation with RTF and/or TBO (logCFU/ml > 5.000).
 Fusobacterium nucleatum
Fusobacterium nucleatum survival was examined 4 ti-
mes by 1 group of researchers. In the first place they per-
formed chemo-mechanical preparation and in the second
place they contaminated the root canals with F. nuclea-
tum. Consequently, they completed root canal prepara-
tion and either used or not laser irradiation with specific
solutions. The logCFU/ml ranges from 4.176 to 6.000
(Table 17) [30].
These results demonstrate no satisfying reduction of
F.nucleatum after diode laser/635 nm/0.1 W irradiation
combined with RTF (reduced transferred fluid) and/or
TBO (toluidine blue), nor after instrumentation and ir-
rigation with RTF and /or TBO (logCFU/ml > 4.176).
 Escherichia coli
Escherichia coli survival was examined 8 times by 2
different groups of researchers. In the first place they
performed chemo-mechanical preparation and in the sec-
ond place they contaminated the root canals with E. coli.
Consequently, they completed root canal preparation and
either used or not laser irradiation with or without spe-
cific solutions. The logCFU/ml ranges from 2.342 to 6.938
(Table 18).
The best treatment protocols for root canal disinfect-
tion in descending order are as follows:
Instrumentation of the root canal followed by irriga-
tion with 1.25% NaOCl
(logCFU/ml = 2.342) [28].
Instrumentation of the root canal and Er:YAG laser/
2,940 nm/0.001 W irradiation
(logCFU/ml = 2.572) [28].
Instrumentation of the root canal followed by irriga-
tion with 1% NaOCl
(logCFU/ml = 3.012) [25].
Instrumentation of the root canal and Er:YAG laser/2940
nm/0.003 W irradiation (logCFU/ml = 3.155) [28].
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 135
 Actinomyces naeslundii
Actinomyces naeslundii survival was examined 4 ti-
mes by 1 group of researchers. In the first place they per-
formed chemo-mechanical preparation and in the second
place they contaminated the root canals with A. naes-
lundii. Consequently, they completed root canal prepara-
tion and either used or not laser irradiation with or with-
out specific solutions. The logCFU/ml ranges from 0 to
3.698 (Table 19) [29].
The best treatment protocols for root canal disinfec-
tion in descending order are as follows:
Instrumentation of the root canal followed by irriga-
tion with 5.25% NaOCl (logCFU/ml = 0).
Instrumentation of the root canal and Nd:YAG laser/
1064 nm/10 Hz/15 sec irradiation (logCFU/ml = 3.053).
Instrumentation of the root canal and Nd:YAG laser/
1064 nm/5 Hz/15 sec irradiation (logCFU/ml = 3.518).
Instrumentation of the root canal solely (logCFU/ml =
3.698).
 Staphylococcus aureus
Staphylococcus aureus survival was examined 8 times
by 2 groups of researchers. In the first place they per-
formed chemo-mechanical preparation and in the second
place they contaminated the root canals with S.aureus.
Consequently, they completed root canal preparation and
either used or not laser irradiation with or without spe-
cific solutions. The logCFU/ml ranges from 2.703 to
6.184 (Table 20).
The best treatment protocols for root canal disinfec-
tion in descending order are as follows:
Instrumentation of the root canal followed by irriga-
tion with 1.25% NaOCl
(logCFU/ml = 2.703) [28].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.001 W irradiation (logCFU/ml = 2.973) [28].
Instrumentation of the root canal followed by irriga-
tion with 1% NaOCl
(logCFU/ml = 3.246) [25].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.003 W irradiation (logCFU/ml = 3.348) [28].
 Pseudomonas ae ruginosa
Pseudomonas aeruginosa survival was examined 4 ti-
mes by 1 group of researchers. In the first place they per-
formed chemo-mechanical preparation and in the second
place they contaminated the root canals with P. aerugi-
nosa. Consequently, they completed root canal prepara-
tion and either used or not laser irradiation with or with-
out specific solutions. The logCFU/ml ranges from 0 to
4.544 (Table 21) [29].
The best treatment protocols for root canal disinfec-
tion in descending order are as follows:
Instrumentation of the root canal followed by irriga-
tion with 5.25% NaOCl (logCFU/ml = 0).
Instrumentation of the root canal and Nd: YAG laser/
1064 nm/10 Hz/15 sec irradiation (logCFU/ml = 3.695).
B) Anal ysis of the Polymicrobial Studies Results
Microbial survival after polymicrobial infection of
root canals was examined 30 times by 6 groups of re-
searchers. In the first place they performed chemo-me-
chanical preparation and in the second place they conta-
minated the root canals with some of the following mi-
croorganisms; E. coli, S. aureus, A. naeslundii, P. aerugi-
nosa, S. anginosus, E. fa ecalis, F. nucleatum, A. israelii,
P. gingivalis and P. int ermed ia. Consequently, they com-
pleted root canal preparation and either used or not laser
irradiation with or without specific solutions. The log-
CFU/ml ranges from 0 to 6.548 (Table 22).
The best treatment protocols for root canal disinfec-
tion in descending order are as follows:
Instrumentation of the root canal followed by irriga-
tion with 5.25% NaOCl (logCFU/ml = 0) [29].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.8 W irradiation
(logCFU/ml = 1.924) [27].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/1.5 W irradiation
(logCFU/ml = 2.113) [27].
Instrumentation of the root canal and Nd:YAG laser/
1064 nm/1.5 W irradiation
(logCFU/ml = 2.477) [27].
Instrumentation of the root canal and Ho:YAG laser/
2130 nm/0.8 W irradiation
(logCFU/ml = 2.491) [27].
Instrumentation of the root canal followed by irriga-
tion with 1.25% NaOCl (logCFU/ml = 2.522) [28].
Instrumentation of the root canal and Ho:YAG laser/
2130 nm/1.5 W irradiation
(logCFU/ml = 2.531) [27].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.001 W irradiation
(logCFU/ml = 2.772) [28].
Instrumentation of the root canal followed by irriga-
tion with 1% NaOCl (logCFU/ml = 3.138) [25].
Instrumentation of the root canal and Nd: YAG laser/
1064 nm/0.8 W irradiation
(logCFU/ml = 3.204) [27].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.003 W irradiation
(logCFU/ml = 3.251) [28].
Instrumentation of the root canal and diode laser/665
nm/1 W irradiation combined with MB as photosensiti-
zing agent and PBS (Phosphate-Buffered Saline) broth
(logCFU/ml = 3.341) [34].
Instrumentation of the root canal and diode laser/665
nm/1 W irradiation combined with MB as photosensiti-
zing agent (logCFU/ml = 3.344) [34].
Instrumentation of the root canal and Nd:YAG laser/
1064 nm/10 Hz/15 sec irradiation(logCFU/ml = 3.374)
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 136
[29].
Instrumentation of the root canal combined with MB
as photosensitizing agent
(logCFU/ml = 3.814) [34].
Instrumentation of the root canal combined with MB
as photosensitizing agent and PBS (Phosphate-Buffered
Saline) broth (logCFU/ml = 3.906) [34].
Instrumentation of the root canal and Nd:YAG laser/
1064 nm/5 Hz/15 sec irradiation (logCFU/ml = 3.993)
[29].
C) Analysis of the Mean Averages of Microbial
Survival in General
The survival of 10 microorganisms well connected with
endodontic problems: E. faecalis, S. anginosus, F. nuclea-
tum, A. israelii, P. gingivalis, P. intermedia, A. naes-
lundii, P. aeruginosa, E. coli, and S. aureus was exam-
ined by 10 groups of researchers regarding the bacteri-
cidal effect of 30 different treatment protocols on them.
In the first place the majority of them performed chemo-
mechanical preparation and in the second place they
contaminated the root canals with one or more microor-
ganisms. Then, they completed the root canal prepara-
tion and either used or not laser irradiation with or
without specific solutions. The logCFU/ml ranges from
0 to 7.940 (Table 23).
The best treatment protocols for root canal disinfec-
tion in descending order are as follows:
Instrumentation of the root canal followed by irriga-
tion with 5.25% NaOCl (logCFU/ml = 0) [29].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.8 W irradiation
(logCFU ml = 1.924) [27].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/1.5 W irradiation
(logCFU/ml = 2.133) [27].
Instrumentation of the root canal and diode laser/665
nm/1 W irradiation with the combined effect of Me-
thylene Blue (MB) as photosensitizing agent (logCFU/
ml = 2.490) [33,34].
Instrumentation of the root canal and Ho:YAG laser/
2130 nm/0.8 W irradiation
(logCFU/ml = 2.491) [27].
Instrumentation of the root canal followed by irriga-
tion with 1.25% NaOCl (logCFU/ml = 2.522) [28].
Instrumentation of the root canal and Ho: YAG laser/
2130 nm/1.5 W irradiation
(logCFU/ml = 2.531) [27].
Instrumentation followed by irrigation with 2.5%
NaOCl (logCFU/ml = 2.602) [31].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.001 W irradiation
(logCFU/ml = 2.772) [28].
Instrumentation of the root canal with the combined
effect of Methylene Blue (MB) as photosensitizing agent
(logCFU/ml = 3.002) [33,34].
Instrumentation of the root canal and diode laser/665
nm/1 W irradiation
(logCFU/ml = 3.033) [33,34].
Instrumentation followed by irrigation with 1% NaOCl
(logCFU/ml = 3.138) [25].
Instrumentation of the root canal and Nd:YAG laser/
1064 nm 0. W irradiation
(logCFU/ml = 3.204) [27].
Instrumentation of the root canal and Er:YAG laser/
2940 nm/0.03 W irradiation
(logCFU/ml = 3.251) [28].
Instrumentation of the root canal and Nd:YAG laser/
1064 nm/10 Hz/15 sec irradiation (logCFU/ml = 3.374)
[29].
Instrumentation of the root canal and Nd:YAG laser /
1064 nm/5 Hz/15 sec irradiation (logCFU/ml = 3.993)
[29].
4. DISCUSSION
Generally, it is well known that certain microorganisms
are related to specific pathological situations in endodon-
tics. Being aware of them is necessary so as to be able to
consider the importance of the disinfection capacity of
each treatment plan. Consequently, it has been proved
that:
1) With symptomatic endodontic disease and apical
bone resorption T. denticola is associated [1].
2) In endodontically infected teeth without a sinus tr-
act E. faecalis and Strept. anginosus were mostly
found [2].
3) In teeth with necrotic pulp P. gingivalis, P. endo-
dontalis, P. intermedia, and P. nigrescens were
identified more frequently [4].
4) With root canal treatment failures E. faecalis is as-
sociated [1,3].
5) In endodontically infected teeth with sinus tracts P.
gingivalis and F. nucleatum were mostly identified
[2].
This systematic review identified 10 in vitro studies
that examined the effectiveness of treatment protocols,
among classical methods and/or various laser applica-
tions in root canal disinfection. The results of these 10
studies indicated that the treatments which provide the
best bactericidal ability regarding each bacterial solely
and all of them were, in descending order of efficacy:
4.1. Enterococcus faecalis
Instrumentation of the root canal and diode laser/665 nm/
1 W irradiation with the combined effect of Methylene
Blue (MB) as photosensitizing agent seemed to be better
in root canal disinfection than instrumentation of the root
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 137
canal and diode laser/665 nm/1 W irradiation. In addi-
tion, the last method was slightly better than instrument-
tation of the root canal combined with MB as photosen-
sitizing agent and significantly better than instrumenta-
tion followed by irrigation with 2.5% NaOCl (sodium
hypochloride).
Regarding the instrumentation and diode laser/830 nm/
3 W irradiation where no CFU/ml was found, this is due
to the lack of sensitivity of the methodology used to de-
tect low concentrations of viable cells (contact with au-
thor).
4.2. Streptococcus anginosus
Instrumentation of the root canal and diode laser/635
nm/0.1 W irradiation combined with RTF (reduced tr-
ansferred fluid) and/or TBO (toluidine blue), as well as
instrumentation with RTF and/or TBO demonstrated
neither accepted nor satisfying reduction of S. anginosus
(logCFU/ml = 5.000, logCFU/ml = 6.079, logCFU/ml =
6.113 and logCFU/ml = 6.204, respectively).
4.3. Fusobacterium nucleatum
Instrumentation of the root canal and diode laser/635
nm/0.1 W irradiation combined with RTF (reduced trans-
ferred fluid) and/or TBO (toluidine blue), as well as in-
strumentation with RTF and/or TBO showed insufficient
disinfection of F. nucleatum. (logCFU/ml = 4.176, log-
CFU/ml = 6, logCFU/ml = 5.939 and logCFU/ml = 5.986,
respectively).
4.4. Escherichia coli
Instrumentation of the root canal followed by irrigation
with 1.25% NaOCl seemed to be better in root canal
disinfection than instrumentation of the root canal and
Er:YAG laser/2940 nm/0.001 W irradiation. Furthermore,
instrumentation of the root canal followed by irrigation
with 1% NaOCl was less effective than the previous treat-
ments, but slightly better than instrumentation of the root
canal and Er:YAG laser/2940 nm/0.003 W irradiation.
4.5. Actinomyces naeslundii
Instrumentation of the root canal followed by irrigation
with 5.25% NaOCl seems to be the best in root canal di-
sinfection as with this concentration no viable cells of
Actinomyces naeslundii are detected. This method is
used and mentioned only by one group of researchers
[29].Concerning the other treatments, they are signifi-
cantly worse and in fact instrumentation of the root canal
and Nd:YAG laser/1064 nm/10 Hz/15 sec irradiation is
slightly better than the same method but with 5 Hz irra-
diation or instrumentation solely.
4.6. Staphylococcus aureus
Instrumentation of the root canal followed by irrigation
with 1.25% NaOCl was better enough than instrumenta-
tion and Er:YAG laser/2940 nm/0.001 W irradiation and
seemed to be better in root canal disinfection than in-
strumentation of the root canal followed by irrigation
with 1%NaOCl and instrumentation with Er:YAG laser/
2940 nm/0.003 W irradiation.
4.7. Pseudomonas aeruginosa
Instrumentation of the root canal followed by irrigation
with 5.25% NaOCl was the best in root canal disinfec-
tion, as no CFU/ml of Pseudomonas aeruginosa was
found. This method was conducted by one group of re-
searchers [29]. Regarding instrumentation and Nd:YAG
laser/1064 nm/10 Hz/15 sec irradiation, it was moder-
ately worse than the previous one.
4.8. Crobial Studies Results
Instrumentation of the root canal followed by irrigation
with 5.25% NaOCl seemed to be the best in root canal
disinfection as no viable cells were detected. However,
this concentration of NaOCl is not used in vivo because
it actively attacks living tissue without contributing sig-
nificantly to treatment [35]. Furthermore, instrumenta-
tion and Er:YAG laser/2940 nm/0.8 W irradiation was
well successful and slightly better than the same treat-
ment but with 1.5 Watt irradiation, which was also better
than instrumentation of the root canal and Nd:YAG la-
ser/1064 nm/1.5 W irradiation. Also, instrumentation of
the root canal and Ho: YAG laser/2130 nm/0.8 W irra-
diation was effective enough, as well as instrumentation
of the root canal followed by irrigation with 1.25%
NaOCl and instrumentation followed with Ho:YAG la-
ser/2130 nm/1.5 W irradiation. Finally, instrumentation
of the root canal and Er:YAG laser/2940 nm/0.001 W
irradiation was less effective than the previous methods.
All the other methods seemed to be worse in root canal
disinfection.
4.9. Microbial Survival in General
Instrumentation of the root canal followed by irrigation
with 5.25% NaOCl seemed to be the best in root canal
disinfection as no viable cells were detected. Instrumen-
tation and Er:YAG laser/2940 nm/0.8 W irradiation was
well successful and slightly better than the same treat-
ment but with 1.5 Watt irradiation. Instrumentation fol-
lowed with diode laser/665 nm/1 W irradiation with the
combined effect of Methylene Blue (MB) as photosensi-
tizing agent showed the same results when compared to
instrumentation of the root canal and Ho:YAG laser/
2130 nm/0.8 W irradiation. Also good results show in-
strumentation of the root canal followed by irrigation
with 1.25% NaOCl and Ho:YAG laser/2130 nm/1.5 W
irradiation which both are slightly better than instru-
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 138
mentation followed by irrigation with 2.5% NaOCl and
Er:YAG laser/2940 nm/0.001 W irradiation. All the other
methods seemed to be worse in root canal disinfection.
5. 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. nucleatum, A. naes-
lundii and P. aeruginosa that remain inside the root canal
even after laser irradiation. In vitro, NaOCl 5% seems to
be the strongest solution in root canal disinfection. Con-
cluding, it seems that new research is needed in order to
set a treatment protocol effective in the root canal disin-
fection from all bacteria mentioned above that are re-
lated to endodontic origin pathology.
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 pa-
tients. 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 pri-
mary endodontic infections in teeth with and without si-
nus tract. Intern ational Endodontic Journal, 41, 508-515.
doi:10.1111/j.1365-2591.2008.01397.x
[3] Gomes, B., Pinheiro, E., Gadê-Neto, C., Sousa, E., Fer-
raz, C., Zaia, A., et al. (2004) Microbiological examina-
tion 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, Por-
phyromonas endodontalis, Prevotella intermedia and Pre-
votella nigrescens in endodontic lesions detected by cul-
ture 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 Endo-
dontics, 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) Innova-
tive wavelengths in endodontic treatment. Lasers in Sur-
gery 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., Núñez, S., Jorge, A.
and Hamblin, M. (2007) Antimicrobial photodynamic
therapy combined with conventional endodontic treat-
ment 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., Ne-
meć, 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 evalua-
tion of the antibacterial effects of intracanal Nd:YAG la-
ser 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. Pho-
tomedicine 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 Ameri-
can Dental Association, 138, 992-1002.
[14] Gutknecht, N., Nuebler-Moritz, M., Burghardt, S. and
Lampert, F. (1997) The efficiency of root canal disinfec-
tion 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 intraca-
nal 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., Christof-
fers, A., Götz, 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 micro-
biologic, 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., França, S., Silva-Sousa, Y., Alfredo, E., Saquy,
P., Estrela, C., et al. (2004) Evaluation of the antimicro-
bial effect of Er:YAG laser irradiation versus 1% sodium
hypochlorite irrigation for root canal disinfection. Aus-
tralian Endodontic Journal, 30, 20-22.
doi:10.1111/j.1747-4477.2004.tb00162.x
[20] Ramsköld, L., Fong, C. and Strömberg, T. (1997) Ther-
mal 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.,
C
opyright © 2011 SciRes. OJST

J. Theodosopoulou et al. / Open Journal of Stomatology 1 (2011) 126-139 139
OJST
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., Gohark-
hay, K., Sperr, W., et al. (2002) The Er:YAG laser in en-
dodontics: 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 en-
dodontic 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. Photomedi-
cine 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 ra-
diation 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 ra-
diation 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 Endodon-
tics, 28, 276-278.
doi:10.1097/00004770-200204000-00004
[30] Bergmans, L., Moisiadis, P., Huybrechts, B., Van Meer-
beek, B. and Quirynen, M.P.L. (2008) Effect of photo-acti-
vated disinfection on endodontic pathogens ex vivo. In-
ternational 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 la-
sers 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 Medi-
cine, 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. La-
sers 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