Table 2 . Studies Using MB as PS .

Author/Year	Type	Bacteria	Groups	PS	Wavelength/ parameter	Results
de Oliveira et al37 2015	In vitro	E. faecalis, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans	1) 1% NaOCl, 2) 5.25% NaOCl, 3) saline+PDT, 4) 1% NaOCl+PDT, 5) 5.25% NaOCl+PDT, 6) Positive control, 7) Negative control	MB 15 μg/mL	660 nm P:100 mW T:90 s	The result shows that PDT can be useful to improve the root canal disinfection.
Wang et al38 2014	In vitro	E. faecalis	1) ultrasonic irrigation with 2.5% NaOCl, 2) methylene blue (MB)-mediated PDT, 3) ultrasonic irrigation and PDT	MB 100 µM	670 nm P:50 mw/100 mW	The combination of ultrasonic irrigation and PDT produced significant antibacterial efficacy against E. faecalis during root canal disinfection.
Silva et al39 2014	In vitro	E. faecalis	1) MG 30 s, 2) MB 30 s, 3) MG 60 s, 4) MB 60 s, 5) MG 120 s, 6) MB 120 s, 7) NaOCl 120 s, 8) Normal saline 120 s	MB	660 nm P: 40 mW, 120 J/cm2 T: 30, 60, or 120	PDT using MB and MG have antibacterial effect against E. faecalis, showing potential to be used as an adjunctive antimicrobial procedure in endodontic therapy.
Bumb et al40 2014	In vitro	E. faecalis	1) Control group, 2) PDT group	MB 25 mg/mL	910 nm P: 1 W, T:3*20 s	It was found that percentage of CFU/mL reduction in PDT group was 96.70%. The result of the study suggested the potential of PDT to be used as an adjunctive antimicrobial procedure after standard endodontic chemo-mechanical debridement.
Xhevdet et al41 2014	In vitro	E. faecalis, Candida albicans	1) PDT 1 min, 2) PDT 3 min, 3) PDT 5 min, 4) NaOCl + PBS + FBS, 5) PUI with NaOCl control	Phenothiazine chloride 10 mg/mL	660 nm 100 mw/cm2 1, 3 and 5 min	Longer times of PDT were recommended. Irrigation with 2.5% NaOCl showed similar results to 5 min irradiation.
Yildirim et al42 2013	In vitro	E. faecalis	1) A 5% sodium hypochlorite (NaOCl), 2) PDT 1 min, 3) PDT 2 min, 4) PDT 4 min	MB 10 mg/mL	660-nm 100 mW/cm2 T: 1, 2, and 4 min	The lowest reduction in the microorganism load was observed in the 1-min irradiation group. There were no significant differences among the groups.
Miranda et al43 2013	In vitro	E. faecalis	1) Control group, 2) Endovac group, 3) PDT group, 4) Endovac + PDT group	MB 25 µg/mL	660 nm 40 mW 5 min	A significant reduction of E. faecalis mean counts was observed in all groups from baseline to both post-therapy samplings; no differences among the groups were detected.
Meire et al282012	In vitro	E. faecalis	1) aPDT (Denfotex Helbo system), 2) Er:YAG laser irradiation (2940 nm, 50 mJ or 100 mJ, 15 Hz, 40 s), 4) Er:YAG laser irradiation (2940 nm, 100 mJ, 15 Hz, 40 s), 5) Nd:YAG laser irradiation (1064 nm, 2 W, 15 Hz, 40 s), 6) immersion in 2.5% (w/v) NaOCl for 1 min, 7) immersion in 2.5% (w/v) NaOCl for 5 min, 8) immersion in 2.5% (w/v) NaOCl for 10 min, 9) immersion in 2.5% (w/v) NaOCl for 30 min in control group, 10) NaOCl 0.25% + Er:YAG	MB 10 mg /mL	660 nm P:75 mW T: 150 s	The use of both commercial aPDT systems resulted in a weak reduction in the number of E. faecalis cells.
Shrestha and Kishen44 2012	In vitro	E. faecalis	CSnps and PDT using photosensitizers, rose bengal (RB), and MB	MB 0.1 and 0.3 mg/mL + CSRnp 10 μmol/L	660-nm Energy density: 5- and 10- J/cm2 T: 1.66 and 3.33 min	The antibacterial activity of PDT using MB and RB was inhibited in a decreasing order by dentin matrix, BSA, pulp, dentin, and LPSs. The effect of tissue inhibitors was higher in the case of PDT with RB.
Cheng et al45 2012	In vitro	E. faecalis	1) Nd:YAG, Er:YAG+NaOCl+normal saline+distilled water 2) Er:YAG+normal saline+distilled water, 3) Er,Cr:YSGG, 4) aPDT, and 5) two control groups	MB 0.01 mg/mL	660 nm P: 0.2 W T: 60 s	After treatment, the bacterial reductions in the experimental groups and the positive control group were significantly greater than that of the negative control group (P<0.001). However, only Er:YAG/NaOCl/NS/DW group showed no bacterial growth (the bacterial reduction reached up to 100%) on the surface of root canal walls or at 100/200µm inside the dentinal tubules.
Ng et al46 2011	In vitro	Mix of 39 species in endodontic infections	1) Chemomechanical debridement (CMD group), 2) CMD + PDT	MB 50 µg/mL	665 nm P: 1 W P: 100 mW/cm2 T: 2*2.5 min 30 J/cm2	PDT significantly reduces residual bacteria within the root canal system.
Upadya et al47 2011	In vitro	E. faecalis	1) aqueous Ca(OH)2 in concentrations of 25%, 50%, and 100%; 2) Chitosan nanoparticles in concentrations of 10 and 20 mg/mL (3, 12, and 24 hours); 3) MB mediated LAD	MB 10, 20 mg/mL	660 nm 2-40 J/cm2	This study highlighted the role of biofilm matrix in providing resistance to antimicrobials.
Nunes et al48 2011	In vitro	E. faecalis	1) control group (untreated), 2) conventionally-treated group (1% NaOCl irrigation), 3) PDT with optical fiber with 90 s, 4) PDT with optical fiber with 180 s, 5) PDT without optical fiber with 90 s, 6) PDT without optical fiber with 180 s	MB 100 µg/mL	660nm P: 90 mW T: 90 s, 180 s	The greatest reduction of E. faecalis (99.99%) was achieved with irrigation with 1% NaOCl. PDT also significantly reduced E. faecalis with no significant statistical difference among the groups.
Garcez et al49 2010	In vivo	Enterococcus sp, Prevotella sp, Actinomyces sp, Peptostreptococcus sp, Streptococcus sp, Fusobacterium sp, Porphyromonas sp, Enterobacter sp, and Propionibacterium sp.	(1) after accessing the root canal, (2) after endodontic therapy, (3) after PDT	chlorin(e6) 60 μmol/L	660 nm 40 mW T: 4 min E: 9.6 J	PDT is an efficient treatment to kill multi-drug resistant microorganisms.
Pagonis et al50 2010	In vitro	E. faecalis	1) No light/no MB nanoparticles (control), (2) treated only with MB-loaded nanoparticles, (3) treated with MB-loaded nanoparticles and light	MB 6.25 mg/mL	665 nm T: 10 min	The synergism of light and MB-loaded nanoparticles led to approximately 2 and 1 log reduction of colony-forming units (CFU/mL) in planktonic phase and root canals, respectively.
Souza et al32 2010	In vitro	E. faecalis	Four experimental groups: 1) MB/NaOCl (PDT with MB and NaOCl as the irrigant), 2) TB/NaOCl (PDT with TBO and NaOCl as the irrigant), 3) MB/NaCl (PDT with MB and NaCl as the irrigant), 4) TB/NaCl (PDT with TB and NaCl as the irrigant).	MB 15 µg/mL	660 nm 40 mW T: 4 min	These in vitro results suggest that PDT with either MB or TBO may not exert a significant supplemental effect to instrumentation/irrigation procedures.
Fimple et al51 2008	In vitro	Actinomyces israelii, Fusobacterium nucleatum subspecies, Porphyromonas gingivalis, and Prevotella intermedia	1) No light/No MB (control group); 2) MB only, 3) Light only, 4) Light and MB	MB 25 µg/mL	665 nm P: 1 W T: 2* 2.5 min 30 J/cm2	PDT can be an effective adjunct to standard endodontic antimicrobial treatment when the PDT parameters are optimized.
George and Kishen52 2008	In vitro	E. faecalis	1) Control group, 2) Root canal– treatment (RCT), 3) Conventional LAD group (MB in water), 4) PF4 group: using MB in emulsion, 5) RCT+PF4 group	MB 50 µmol/L	664 nm 31.84 J/cm2	The modified photosensitizer formulation will have potential advantages in endodontic disinfection.
George and Kishen53 2007	In vitro	E. faecalis	1) MB activated by visible light, 2) sodium hypochlorite (NaOCl)	MB 10 μmol/L	664 nm T: 20 min P: 30 mW E: 36 J	E. faecalis cells were killed at a faster rate than fibroblasts. An irradiation dose producing 97.7% bacterial killing showed only 30% fibroblast dysfunction.
Foschi et al54 2007	In vitro	E. faecalis	1) No light/no MB (control group); 2) MB only (MB group); 3) light only (light group); 4) light and MB (PDT group).	MB 6.25 mg/mL	665 nm P: 1 W T: 10 min	PDT achieved 77.5% reduction of E. faecalis viability. MB alone and light alone reduced bacterial viability by 19.5% and 40.5%, respectively.
Soukos et al55 2006	In vitro	Endodontic pathogens in planktonic phase as well as on E. faecalis	1) Light+/PS+, 2) Light+/ PS-, 3) Light-/PS+, 4) Light-/PS-	MB 25 µg/mL	665 nm P: 1 W T: 5 min 30 J/cm2	PDT may be developed as an adjunctive procedure to kill residual bacteria in the root canal system after standard endodontic treatment.