Information sources and search strategy
Study selection and data collection process
On Er:YAG laser irradiation, the eradication of Enterococcus faecalis ranged from 98.8 up to 99.99% using 2.5–6% NaOCl. That bacteria eradication ranged from 98.5 up to 99.997% for ultrasonic irrigation in combination with 2.5–6% NaOCl [26, 33, 49, 55]. The bacterial reduction reached 71.4% for ultrasonic irrigation and 90.2% for LAI using water irrigation solution, while 69.8–78.1% was recorded for ultrasonic irrigation and 91.9–97.6% under saline solution irrigation [26, 33, 56].
On the ultrasonic irrigation, the percentage of bacteria eradication ranged from 1.92 up to 69.3%, being the highest percentages recorded for 3%NaOCl-17%EDTA-3%NaOCl solutions followed by 6%NaOCl-18%Etidronic acid and 3%NaOCl-17%EDTA solutions . The use of 6%NaOCl-18%Etidronic acid solutions provided the highest percentage of bacteria eradication, followed by 3%NaOCl-17%EDTA-3%NaOCl, 3%NaOCl-17%EDTA, and saline solutions.
On the Er,Cr:YSGG laser, the decrease of Enterococcus faecalis was recorded at around 99.96–99.99% in 2.5% NaOCl irrigation [10, 11]. Mean values of colony-forming unit (CFU/cm2) were recorded at 2.24 × 102 when Er,Cr:YSGG laser was combined with 0.5% NaOCl or 4% NaOCl and 15% EDTAC solutions, while 1.38 × 105 CFU/cm2 was measured for Er,Cr:YSGG laser irradiation free of disinfection solution, and 2.37 × 104 CFU/cm2 was recorded for ultrasound with 0.5% NaOCl or 4% NaOCl and 15% EDTAC solutions [60‐62].
The smear layer removal with the use of a Er,Cr:YSGG laser was recorded at 1 mm from the apex. The percentage of samples that revealed dentinal tubules open and clean (no smear layer) was around 10% for passive ultrasonic irrigation, 100% for LAI (60 s activation and 30/.02 file), 30% for LAI (30 s activation, 30/.02 file), and 50% for LAI (60 s activation, 20/.02 file) . Also, the removal of the smear layer was achieved when using ultrasonic irrigation [20‐22, 45, 51].
Er:YAG laser irradiation combined with 5% NaOCl and 17% EDTA solutions showed penetration depth mean values of 961 μm into canal dentin using the LAI PIPSTM approach, while a 722 μm penetration depth was recorded for LAI SWEEPSTM. Passive ultrasonic reached a mean penetration depth of 823 μm in canal dentin .
Study design/bacteria growth conditions and analyses
Laser irradiation parameters
Shan et al. (2022)
Comparison of the effectiveness of three disinfection measures including conventional irrigation, ultrasonic assisted irrigation, and ER:YAG laser-assisted irrigation through conventionally or minimally invasive access.
66 extracted maxillary first molars were randomly divided into (A) conventional irrigation (CI), (B) passive ultrasonic agitation (PUI), and (C) Er:YAG laser-activated irrigation (LAI).
E. faecalis infection model was established inside all root canals after instrumentation was performed up to ProTaper Universal F2.
CFU per milliliter was calculated.
2940 nm Er:YAG (Fotona LightWalker, Fotona, Slovenia) laser was set to SSP mode, 20 mJ, 15 Hz, 0.3 W, fitted with a 21-mm-long, 400-micron endodontic conical fiber tip, and the fiber tip was placed in the center of the pulp chamber without contact with the bottom of the pulp chamber.
Suprasson P5 ultrasonic K25/25 mm (Acteon, France) at an energy level of 6. The irrigation tip was used with up and down motion without touching the root canal wall for 20 s. Each canal was ultrasonically agitated 3 times and rinsed with 2 mL of normal saline as the final step.
1% NaOCl and 17% EDTA
The disinfection effect of Er:YAG laser- or ultrasonic-assisted computer-guided minimally invasive access is similar to conventionally invasive access, and Er:YAG laser was better than ultrasonic in removing bacteria from dentinal tubules and it is more suitable for minimally invasive root canal treatment.
Aung et al. (2021)
Evaluating the effectiveness of Er:YAG laser-activated irrigation (LAI) for cleaning the apical root canal area beyond a ledge.
88 human maxillary molars with either a mesiobuccal or distobuccal canal. Following instrumentation to a size of 25/0.02 taper, a ledge was created at 2.2–0.7 mm short of the apex and checked using micro-CT. Samples were divided into four groups: syringe irrigation (SI), ultrasonic-activated irrigation (UAI), agitation with the XP-endo Finisher (XP), and LAI. The remaining debris and smear layer at apical 1-mm region were analyzed by SEM.
2940 nm Er:YAG (MEY-1-A, Morita Manufacturing, Japan) was set to SSP mode, 20 mJ/s (0.6W), 20s exposure time, 300 μs pulse duration, fitted with a 21-mm-long, 200-micron endodontic conical fiber tip (R200T). The fiber tip was placed up to the ledge within the tooth root canal.
Stainless-steel ultrasonic tip (SC Point 4; 19 mm, u = 200 lm; Osada) is placed up to the ledge and activated with a gentle up-and-down movement without touching the canal walls at a power setting of 3 (at a frequency of 30 kHz and 3.6 W) for 20 s after each 3 mL irrigation.
9 mL of 6% NaOCl
6 mL of 6% NaOCl plus 3 mL of 14.3% EDTA
In the apical area of ledged canals, the cleaning efficacy of Er:YAG LAI with/without EDTA was higher than SI and XP but was comparable with UAI.
Aydin et al. (2020)
Comparison of the antimicrobial effects of two different irrigation solutions activated with Er,Cr:YSGG laser or an ultrasonic system and photodynamic therapy on Enterococcus faecalis.
72 single-rooted human permanent incisors were endodontically prepared with ProTaper Universal rotary instruments and incubated with E. faecalis (ATCC 29212) for 4 weeks.
CFU per milliliter was calculated. Scanning electron microscopy (SEM) was for bacteria examination.
GIII and IV: Er,Cr:YSGG laser, (Waterlase, Biolase, USA) (30 s), the wavelength of 2780 nm, 4-mm section of the RFT2 fiber tip, 0.25 W, 20 Hz, 10% air, and waterless mode.
GV and VI: piezoelectric ultrasonic unit (EMS, Switzerland) (30 s), short vertical movements, 1 mm shorter than the working length into the canal.
GI: 5 mL of 2.5% NaOCl for 60 s
GII: 5 mL of 2% CHX for 60 s
GIII: 30 s using 5 mL of 2.5% NaOCl
GIV: 30 s using 5 mL of 2% CHX
GV: 30 s using 5 mL of 2.5% NaOCl
GVI: 30 s using 5 mL of 2% CHX
GVII: toluidine blue
GI, GIII, GV: 5 mL of 5% sodium thiosulfate solution
GII, GIV, GVII: canals washed with Tween 80 solution for 1 min, then 2 mL of distilled water, and 2 mL of 5% sodium thiosulfate.
On LAI, microbial reduction rate was around 99.9658% ± 0.03075% for the activation of NaOCl and 99.9551% ± 0.03852% for the activation of CHX.
For the ultrasonic system, that was around 99.9616% ± 0.11401% for activation of NaOCl and 99.9524% ± 0.08276% for activation of CHX.
Betancourt et al. (2020)
Comparison of the antibacterial effectiveness of 0.5% NaOCl activated by the Er,Cr:YSGG LAI and passive ultrasonic irrigation against a 10-day-old intracanal Enterococcus faecalis biofilm.
72 single-rooted human teeth prepared with crown-down/step-back technique with files up to the master #55 K-File (Dentsply Maillefer, Switzerland).
Dental roots placed in Eppendorf tubes and incubated in tryptic soy broth (TSB) medium containing E. faecalis (ATCC29212) at 37 °C for 10 days.
Logarithmic transformation of CFU values and bactericidal index calculation. SEM used.
GI and GII: Er,Cr:YSGG-pulsed laser (Waterlase iPlus, Biolase, USA), 2780 nm wavelength, equipped with a RFT 2 tip (Endolase, Biolase, USA), 200 μm in diameter, length of 21 mm, calibration factor > 0.55; 0.55 W average power at 10 Hz (60 μs/pulse); irradiance 0.90 W/cm2 yielding an energy density of 55 J/cm2.
Total activation time = 60 s: 30 s activation, rest phase of 30 s, and ending with 30 s of activation.
GIII and GIV: ultrasonic device (Newtron® P5 XS, Acteon, France), equipped with a handpiece (Newtron Slim B.LED; Satelec Acteon, France) 30 kHz frequency in the endo-mode (medium power) used. Non-cutting ultrasonic tip (Irrisafe; Acteon, France) stainless steel 25/.00, 25 mm in length inserted WL-2 mm, with short vertical moves (2–3 mm).
Total activation time = 60 s: 30 s activation, rest phase of 30 s, and ending with 30 s of activation
GI: 0.5% NaOCl+Er,Cr:YSGG
GIII: 0.5% NaOCl+PUI
GV: positive control (no treatment)
GVI: negative control (no bacteria)
LAI: 2 mL of 5% sodium thiosulfate was used to neutralize the remaining NaOCl and washed with 1 mL of saline.
PUI: 2 mL of 5% thiosulfate and saline with 1 mL of saline.
Median CFUs/cm2: nn LAI, 4.45 × 102 with NaOCl and 4.43 × 104 with saline. On PUI, 1.89 × 104 for NaOCl and 3.67 × 104 with saline.
Kurzmann et al. (2019)
Validation of an artificial resin root canal wall groove model mimicking the situation of natural roots with a groove of identical dimensions on debris removal out of these grooves and to evaluate erbium LAI with two conical tips at PIPSTM settings.
Split RCWGM used (resin blocks and roots of maxillary canines) with a canal size 40/0.06. Grooves in the apical third filled with stained dentinal debris. Quantity of remaining dentine debris evaluated on a numerical scale. Statistical analysis performed by means of proportional odds logistic regression, equivalence testing, and Wald’s tests.
2940 nm Er:YAG with X-Pulse 400/14 tip or PIPSTM 400/14 tip at PIPSTM settings (20 mJ, 50 μs, 20 Hz) and with the fiber (IN) or (OUT) the canal: IN during 1 × 20 s and OUT during 1 × 20 s, 2 × 20 s, 3 × 20 s, 30 s, 2 × 30 s, and 1 × 60 s.
25/25 non-cutting no. 20 Irrisafe (Acteon, France) was used in the canal at a power setting of 50% of the Suprasson Pmax Newtron (Acteon, France) with the tip kept steady WL-1 mm for 3 times 20 s. In between activation, canal flushed with 3 mL distilled water during 20 s.
The most extreme value was calculated for UAI compared with PIPSTM out 1 × 20 s with a P value of 0.053.
Betancourt et al. (2019)
Comparison of the antimicrobial efficacy of Er,Cr:YSGG LAI and passive ultrasonic irrigation of NaOCl 0.5% against E. faecalis biofilm.
Artificial root canal model. E. faecalis (ATCC 29,212) maintained by weekly subculturing in TSA plates. Cultured in 40 mL of TSB medium inoculating a single colony grown on TSA at 37 °C. After 24 h incubation, liquid culture was diluted 100 times in fresh TSB medium, adjusted spectropho-tometrically (Unicam UV-2 at 600 nm) to OD600 = 0.018 (i.e., 3.4 × 107 CFUs/mL) and used.
GV and GVI: 2780 nm Er,Cr:YSGG pulsed laser (Waterlase iPlus, Biolase, USA). Settings: 1-W power, 10-Hz repetition rate, 100 mJ per pulse energy, and 140-μs pulse duration. RFT 2 tip (Endolase, Biolase, USA) 200 μm in diameter, length 21 mm, calibration factor of > 0.55) used.
The real power was 0.55 W at 10 Hz, 55 mJ per pulse.
GVII and GVIII: ultrasonic device (Newtron® P5 XS, Acteon, France) with non-cutting ultrasonic tip (Irrisafe, Acteon, France) stainless steel 25/.00, 25 mm in length, mounted in a handpiece unit (Newtron Slim B.LED, Acteon, France), inserted only into the cylindrical irrigant reservoir. Tip placed for each pipette with short moves (2–3 mm) up and down, directed to the extremity of the model device, with a frequency of 30 kHz in the endo mode (medium power). No additional irrigation performed during PUI cycles (60 s).
GII: NaOCl 0.5%
GIII: NaOCl 5%
GV: Saline + LAI
GVI: NaOCl 0.5% + LAI
GVII: Saline + PUI
GVIII: NaOCl 0.5% + PUI.
On LAI, 1.38 × 105 for Er,Cr:YSGG only, 7.00 × 103 with saline, < 10 with NaOCl 0.5%.
On PUI, 4.55 × 104 with saline, and 5.21 × 104 with NaOCl 0.5%.
Race et al. (2019)
Investigation of the efficacy of Er,Cr:YSGG laser and ultrasonic activated irrigation on eradicating a mixed-species biofilm grown in root canals with complex anatomy.
Biofilm grown over 4-weeks in the root canals of decoronated human mandibular molar teeth. Control roots received no further treatment. Remaining roots prepared with rotary TF instrument up to a final size of 25/04. Cellular viability was determined using serial plating. One tooth from each group subjected to qualitative SEM analysis. CFU per milliliter were calculated manually for each sample to determine the bacterial viability. Statistical analysis was performed using the PRISM software.
GIII and GIV: Er,Cr:YSSG laser (Waterlase, Biolase, USA) and RFT 3 17 mm laser tip (Endolase, Biolase, USA) was used to activate the irrigating solution. Tip stopped at 2 mm into the canal. The air and water functions were turned off. Settings: 0.5 W and 0.75 W, pulse repetition rate of 20 Hz.
GII: size 20 SATELEC®IrrisafeTMfile (Acteon, France) mounted in an ultrasonic device (SybronEndo, Kerr Dental, USA) was used on a medium power (7/15) setting. The tip was withdrawn approximately 2 mm into the canal.
GI: no treatment control
GII: 4% NaOCl and 15% EDTAC
GIII: 4% (v/v) NaOCl and 15% (w/v) EDTAC-LAI at 0.5 W
GIV: 4% (v/v) NaOCl and 15% (w/v) EDTAC-LAI at 0.75 W
GII–IV were irrigated with 5 mL of sodium thiosulphate for 1 min.
Median CFU/mL: 212.3 for UAI, 110.78 for LAI (0.50 W) and 331.52 for LAI (0.75 W).
Swimberghe et al. (2019)
Evaluation of the efficacy of sonically, ultrasonically, and laser-activated irrigation in removing a biofilm-mimicking hydrogel from the isthmus in a root canal model.
Transparent resin blocks containing 2 standardized root canals connected by an isthmus were used as the test model. Isthmus filled with a hydrogel containing dentine debris. Standardized images of the isthmus taken before and after irrigation and amount of removed hydrogel determined using image analysis software and compared across groups using Welch’s ANOVA (P ≤ 0.05).
GIV: 2940 nm Er:YAG-laser (20 Hz, 50 μs, 20 mJ, PIPSTM tip at the canal entrance). Air and water spray turned off.
GIII: non-cutting size 25 file (Irrisafe, Acteon, France) driven by an ultrasonic device (P5 Newton, Acteon, France) at power setting 7 used in the canal. File positioned centrally in the canal at 2 mm from the apical terminus (corresponding with the middle of the isthmus), with the oscillation direction towards the isthmus.
GI, GII, GIII, GIV, and control group: water.
Proportion of removed hydrogel was 71.4% for UAI and 90.2% for LAI.
Hage et al. (2019)
Assessment of the antibacterial action of sonically, ultrasonically and laser-activated irrigation and 5.25% NaOCl on Enterococcus faecalis in an infected tooth.
44 extracted mandibular premolars mechanically prepared up to a size of F2 Protaper Gold (Dentsply; Maillefer, Switzerland), sterilized and inoculated with E. faecalis for 1 week. CFU counts were measured and the Kolmogorov–Smirnov, Wilcoxon, Kruskal–Wallis, and Mann–Whitney tests were used to determine the differences.
GI: 2940 nm Er:YAG laser (Light Walker DT, Fotona, Slovenia) with a H14 handpiece (LightWalker Handpiece, Fotona, Slovenia) holding a conical PIPSTM tip (9 mm long; 600 μm diameter). Fiber tip positioned at the entrance of the canal. Settings: pulse energy 0.02 J, frequency 15 Hz, pulse duration 50 μs.
GIII: ultrasonic irrigation with EndoUltra (MicroMega, France), activator tip of 15/0.2 at 40 kHz. Vertical movement over a distance of 3 mm without pressure for 30 s starting 1 mm from the apical terminus. Procedure repeated 3 times.
GI: (PIPSTM): 3 mL of 5.25% NaOCl (0.05 mL/s). Procedure repeated 3 times. A total of 3 mL of distilled water followed the irrigation protocol.
GII: sonic irrigation by EDDY. Canal flushed with 3 mL irrigant (0.05 mL/s) (5.25% NaOCl) between activation cycle.
GIII: ultrasonic irrigation, 5 mL of 5.25% NaOCl solution In between each activation cycle, canal flushed with 3 mL irrigant (5.25% NaOCl).
GIV: 5.25% NaOCl.
Percentage of decrease of CFU: 99.997% for UAI, and 99.998% for LAI.
Galler et al. (2019)
Comparison of the penetration depths of endodontic irrigants into the dentinal tubules of extracted teeth when using several activation methods.
90 extracted human teeth prepared to size 40, .06 taper. Methylene blue inserted into the canals and activated according to the groups (I—V). Teeth sectioned horizontally, imaged under a light microscope, and dyed penetration depths measured in 6 sections per tooth and 24 points on a virtual clock-face per section. Data analyzed statistically by non-parametric tests for whole teeth and separately for coronal, middle, and apical thirds.
GIII: 20 mJ, 15 Hz, 0.30 W, SSP mode, air/water turned off (FOTONA, Slovenia).
GV: SWEEPSTM (shock wave-enhanced emission photoacoustic streaming), 20 mJ, 15 Hz, 0.30 W, SWEEPSTM mode, air/water turned off.
GII: IRRI K 25/25 (VDW GmbH, Germany) and the appendant ultrasonic device (VDW.ULTRA, VDW, Germany) at 25% intensity.
Canals irrigated with NaOCl (5%, 60 °C)
Final irrigation: NaOCl (5 mL, 1 min)
Ultrapure water (5 mL, 1 min)
EDTA (5 mL, 1 min), activation for 30 s
Ultrapure water (5 mL, 1 min)
NaOCl (5 mL, 1 min), activation for 30 s, resting phase 30 s, activation for 30 s
Control: no activation, final irrigation with 1 mL of 5% NaOCl.
Median penetration depths for whole canals from highest to lowest were EDDY (985.5 μm) > PIPSTM (961.5 μm) > PUI (823.8 μm) > MDA (775.0 μm) > SWEEPSTM (722.0 μm).
Dönmez Özkan et al. (2018)
Comparison of the debris removal efficacies of irrigation activation techniques using ex vivo biomolecular film.
50 human mandibular premolars prepared and freshly prepared collagen solutions applied into the root canals using a peristaltic pump. Post-irrigation solution collected in beakers containing 3% sodium thiosulfate. Residual protein levels in NaOCl solution evaluated by the Bradford method. Data nalyzed using ANOVA with Duncan’s post hoc tests (α = 0.05).
GV: 2940 nm Er:YAG laser (Fotona, Slovenia). A 14-mm-long 300-μm quartz laser tip was used at 0.3 W, 15 Hz, and 20 mJ per pulse. Water and air turned off. 10 s of irrigation followed by 20 s of activation with tip placed into the access cavity.
GIV: EMS equipped with ultrasonic tip (ESI, EMS, Switzerland) size 15, 0.02 taper inserted into the root canal WL-2 mm. Tip activated at a frequency cycle of 28–32 kHz for 20 s. Procedure repeated three times.
During instrumentation: 5.25% NaOCl. Final wash with 2 mL of distilled water.
Activation: 3 mL of 5.25% NaOCl.
After procedures: 3% sodium thiosulfate.
Residual protein levels in the 5.25% NaOCl solution were > 7μg/mL for PUI and > 11 μg/mL for PIPSTM, (control > 5 μg/mL).
Passalidou et al. (2018)
Comparison in vitro of the canal and isthmus debridement of manual-dynamic, passive ultrasonic, and laser-activated irrigation with an Er:YAG laser in mesial roots of human mandibular molars.
50 extracted mandibular molars with an isthmus were embedded in resin and sectioned axially 4 mm from the apex. The teeth were reassembled with guide pins and bolts, and the mesial canals were instrumented up to a ProTaper F2 rotary file (Dentsply; Maillefer, Switzerland). Teeth were subjected to cone-beam computed tomographic imaging. Statistical analysis was performed using SPSS.
GIV: 2.940 nm Er:YAG laser (AT Fidelis; Fotona, Slovenia) equipped with a handpiece (R14-PIPSTM, Fotona, Slovenia) holding a conical 400 μm diameter fiber (XPulseTM 400/14, Fotona, Slovenia). Fiber tip placed in the canal entrance and activated for 3 × 20 s. Pulse energy: 20 mJ, frequency: 20 Hz, pulse length: 50 μs.
GV: 600 μm diameter fiber (XPulseTM 600/14; Fotona, Slovenia) placed in the pulp chamber over the canal
GIII: Suprasson Pmax Newtron (Fotona, Fotona, Slovenia), used with non-cutting #20 file (Irrisafe, Fotona, Slovenia), in the canal for 3 × 20 s at 50% power. The file was prebent and inserted up to the WL-1 mm.
1 mL 2.5% NaOCl
GI and GII: 4 mL 2.5% NaOCl
GIII, GIV, and GV: 1 mL of NaOCl in between each cycle and finally 2 mL of NaOCl
Percentage of debris difference in the canals: 19.1% for LAI (400 μm), 26.3% for LAI (600 μm) and 20.9% for UAI.
In the isthmus, 58.8% for LAI (400 μm), 46.9% for LAI (600 μm), and 27.4% for UAI.
Mancini et al. (2018)
Comparison of the efficacy of EndoActivator, EndoVac, PUI, and LAI methods in removing the smear layer from root canals.
80 single-rooted mandibular premolars decoronated to a standardized length of 15 mm. Specimens shaped to ProTaper F4 (Dentsply Maillefer, Switzerland) and irrigated with 5.25% NaOCl at 37 °C. SEM used scores analyzed by the Kruskal-Wallis and Mann-Whitney U tests.
GIV: 2.940 nm Er:YAG laser (AT Fidelis, Fotona, Slovenia) equipped with a handpiece (R14, Fotona, Slovenia) holding a plain 300-μm diameter fiber tip, 14 mm in length (PRECISO 300/14, Fotona, Slovenia). Tip inserted WL-5 and held still during 5 s of laser activation, four repetitions with 5 s interval. Pulse energy: 60 mJ, frequency: 20 Hz, pulse length: 50 μs. Fiber’s efficiency: 90%; air and water spray turned off.
GI: MiniEndo II (SybronEndo, Kerr Dental, USA) with a no. 15 K-file (Dentsply Maillefer, Switzerland), with power set at 5 for 1 min at WL-1 mm.
During instrumentation: 3 mL 5.25% NaOCl at 37 °C, then 3 mL 17% EDTA left in the canal for 1 min and rinsed with 3 mL of 5.25% NaOCl at 37 °C.
Final irrigation: 5.25% NaOCl at 37 °C activated for GI (PUI), GII (EA), GIII (EV), and GIV (LAI)
G+ (positive control) and G- (negative control) were not activated.
Between LAI and PUI, PUI had better score percentages of root canal treated for PUI with 3% at 1 mm and at 3 mm from the apex. LAI obtained better score than PUI with 2% at 5 mm and 8 mm from the apex.
They both were less efficient than EV and EA.
Cheng et al. (2017)
Evaluation of the bactericidal effect of Er:YAG laser-activated sodium hypochlorite irrigation on biofilms of Enterococcus faecalis clinical isolate.
90 E. faecalis strains isolated from 39 root-filled teeth with periapical lesions. Human root canals prepared to a 40#/.04 K3 instrument and contaminated with the E. faecalis isolate that presented the strongest biofilm formation ability for 4 weeks. After treatment, root canals were examined using SEM. Bacterial reductions evaluated using the cell count method.
GV and GVII: 2940 nm Er:YAG laser (Fotona, Slovenia) with a PIPSTM tip (diameter = 300 μm, Fotona, Slovenia), placed at 1 mm below the orifice of the canals. Pulse energy: 20 mJ, frequency: 25 Hz, power: 0.5 W, pulse length: 50 μs. Laser activated at 15 s intervals every 15 s.
GIV and GVI: ultrasound instrument (UDS-L; Guilin Wood-pecker Medical Instrument Co.) equipped with a standard ultrasonic needle (#25 K-type nickel-titanium file, 32.5 mm in length) needle at 1–2 mm of the root apex.
Irrigation with 0.5% NaOCl during instrumentation, then NaOCl (5.25%, 5 mL, 4 min) and EDTA (17%, pH 7.2, 5 mL, 4 min)
GII: NS (5 mL, 60 s)
GIII: 5.25% NaOCl (5 mL, 60s)
GIV: UAI + NS (5 mL, 60 s)
GV: LAI + NS (5 mL, 30 s)
GVI: UAI + 5.25% NaOCl (5mL, 60s)
GVII: LAI + 5.25% NaOCl (5 mL, 30 s).
On Er:YAG, 98.8% with NaOCl and 91.9% with saline.
On ultrasounds, 98.6% with NaOCl and 78.1% with saline. No significant difference in bacterial reduction was observed between the UAI + NaOCl and Er:YAG + NaOCl groups (P > 0.05).
De Meyer et al. (2017)
Evaluation of the antimicrobial effect of LAI on biofilms formed in simulated root canals.
Enterococcus faecalis and Streptococcus mutans were grown in a resin root canal model. Biofilms formed over 48 h and subsequently subjected to treatments for 20 s.
Surviving bacteria were harvested, and the number of CFU was determined by plate counting and compared across groups (ANOVA, P ≤ 0.05).
GIV, GV, and GVI: 2940 nm Er:YAG laser (AT Fidelis, Fotona, Slovenia) frequency: 20 Hz, pulse length: 50 μs, power: 20 or 40 mJ, conical fiber tip at two positions. Equipped with a handpiece (R14-PIPSTM, Fotona, Slovenia), holding a conical 400-μm fiber tip, 14 mm in length (X-pulse 400/14). The air and water spray was turned off.
GIV (LAI 1): 20 mJ, tip at the entrance
GV (LAI 2): 40 mJ, tip at the entrance
GVI (LAI 3): 20 mJ, tip at 6 mm from the apex.
GIII: non-cutting size 20 file (Irrisafe, Acteon, France) driven by an ultrasonic device (Suprasson Pmax Newtron, Satelec, Acteon, France) at 50% power for 20 s, WL-1 mm.
GI (untreated control).
GII (syringe), GIII (UAI), GIV (LAI 1), GV (LAI 2), and GVI (LAI 3): experiments executed with both sterile saline (0.85% [w/v] NaCl) and NaOCl (2.5%) as the irrigant during 20 s.
For irrigation with saline, UAI had a 0.52 log10 reduction in viable count, and > 1 log10 reduction for LAI groups. With NaOCl, the highest reductions were observed in the UAI and LAI 2 and 3 groups, with 3.35, 3.37, and 3.35 log10.
Akcay et al. (2017)
Evaluation of the efficacy of LAI using an (Er:YAG) laser with a novel tip design (PIPSTM), Er:YAG laser with PrecisoTM tip, sonic activation, and passive ultrasonic activation on the final irrigation solution penetration into dentinal tubules.
65 extracted single-rooted human mandibular premolars instrumented up to size 40 and randomly divided into 5 groups. After treatment, Specimens were sectioned at 2.5 and 8 mm from the apex and then examined under a confocal microscope to calculate the dentinal tubule penetration area. Data analyzed using two-way analysis of variance (ANOVA) and Tukey’s post hoc tests (P = 0.05).
2940 nm Er:YAG laser (Fidelis AT, fotona, Slovenia). Equipped with a 14-mm long, conical 300-μm-diameter PIPSTM tip. Power: 0.9 W, energy: 30 mJ each pulse, frequency: 30 Hz, in the very short pulse (VSP) mode. Air and water switched off.
For the 300-μm PrecisoTM tip, the parameters were 1 W, 50 mJ per pulse, 20 Hz, and in VSP mode, 5 mm from the WL.
Ultrasonic device 5 Newtron XS (Acteon, France), with a stainless steel file #20/25 (Irrisafe tip, Acteon, France) placed WL-2 mm with an up-and-down motion, activated for 1 min at the recommended power setting of blue “11.”
Irrigated with 2 mL of 5% NaOCl during instrumentation. Final wash using 5 mL of 17% EDTA for 1 min and 5 mL of 5% NaOCl (labeled with fluorescent dye) for 1 min.
Total means of the dentinal tubule penetration area of the final irrigation solution to root canal dentin were 1054 mm2 for LAI (PIPSTM), 1072 mm2 for LAI (PRECISOTM tip) and 0.690 mm2 for PUI.
Verstraeten et al. (2017)
Investigation of the efficacy of different irrigant activation techniques on removal of accumulated hard tissue debris (AHTD) in mesial roots of human mandibular molars.
30 extracted human mandibular molars with an isthmus between the mesial root canals selected based on micro-CT (μCT) scans. Mesial canals instrumented to an apical diameter ISO30 using ProTaper rotary files (Dentsply; Maillefer, Switzerland).
GII and GIII: a 2940 nm Er:YAG laser (AT Fidelis, Fotona, Slovenia) equipped with a handpiece (R14-PIPSTM, Fotona, Slovenia) holding a plain 300 μm diameter fiber tip (PRECISOTM 300/14), 14 mm in length. Fiber kept WL-5 mm and moved up and down each canal for 3 × 20 s.
GI: Suprasson Pmax Newtron, with size 20 prebent Irrisafe file (Acteon, France), for 3 × 20 s, 2–4 mm from the WL at power setting “blue 4” (frequency 30 kHz, displacement amplitude about 30 μm according to the manufacturer).
During instrumentation: 1 mL of 2.5% NaOCl after each file, final rinse with 2 mL EDTA (17%) and then 2 mL of NaOCl.
GI (UAI): canal rinsed with 1 mL of NaOCl each 20 s.
GII (LAI) and GIII (PIPSTM): intermittent flush of 1 mL of NaOCl.
Final flush: 2 mL of NaOCl.
The amount of the remaining debris after LAI and PIPSTM treatment was slightly less than that after UAI (removal of 5.78 and 5.91 vol% versus 5.31 vol%).
Ayranci et al. (2016)
Investigation of the evaluation of LAI on the removal of the smear layer as compared to passive ultrasonic irrigation.
48 single-rooted, upper-central incisor teeth selected and standardized to a length of 19 mm.
Preparation with ProTaper rotary instruments (Dentsply; Maillefer, Switzerland) up to size #40 (F4).
SCANNING 38:121–127, 2016.©2015 Wiley Periodicals, Inc.
GIII and GIV: 2940 nm Er:YAG laser system (Fidelis AT, fotona, Slovenia) was used. Power: 20 W, frequency: 50 Hz. A 14-mm-long conical, cylindrical (tapered) 300-μm fiber tip was used with 50-ms pulse duration. The flow rate was approximately 0.04 mL/s for all groups. Tip inserted in the pulp chamber.
GI and GII: ultrasonic device (Anthos u-PZ6, Imola, Italy) equipped with a smooth ultrasonic file (15/02). Tip inserted WL-1 mm and activated for 60 s at 25% power.
During instrumentation: 2 mL 2.5% mL of NaOCl
GI: PUI with 5 mL of 2.5% NaOCl for 60 s
GII: PUI with 2.5 mL of 17% EDTA and 2.5 mL of 2.5% NaOCl each for 30 s
GIII: LAI with 5 mL of 2.5% NaOCl for 60 s
GIV: LAI with 2.5 mL of 17% EDTA and 2.5 mL of 2.5% NaOCl each for 30 s.
In the apical third, the mean scores for smear layer removal was 4.91 for PUI + NaOCl, 4.16 for PUI + EDTA + NaOCl, 5.00 for LAI + NaOCl, and 2.50 for LAI + EDTA + NaOCl.
In the middle third, the mean scores was 4.50 for PUI + NaOCl, 2.16 for PUI + EDTA + NaOCl, 4.58 for LAI + NaOCl, and 1.08 for LAI + EDTA + NaOCl.
Keles et al. (2016)
Comparison of the efficacy of different irrigation activation methods to remove smear layer and debris from oval-shaped root canals following retreatment.
90 mandibular canines with oval-shaped root canals selected. Retreatment performed with R-Endo retreatment files. Roots longitudinally split into two following the grooves using a separating disc. The two root halves were considered as separate samples. SEM images were used. IBM SPSS Statistics 22 software (PASW Statistics 20; SPSS Inc.) was used.
GIV: 2940 nm, flat-tipped Er:YAG laser (Fidelis AT, Fotona, Slovenia). Power: 1 W, frequency: 20 Hz, energy: 50 mJ per pulse with a pulse duration of 50 μs. Air and water switched off. A 14 mm long and 300 μm in diameter plain optical fiber tip (PrecisoTM 300/14 Photon A) was placed at WL-3 mm, activated, gently pulled from apical to coronal region with helical motion, and then reintroduced towards the apex.
GV: a 300 μm in diameter and 14 mm long conical PIPSTM fiber tip (Fidelis, Fotona, Slovenia) was at 20 Hz, 45 mJ with a pulse duration of 50 μs, and 0.9 W of power. Tip placed at the access opening of pulp chamber.
GVI: 1064 nm Nd:YAG laser (Fidelis AT, Fotona, Slovenia) at 1 W, 20 Hz and 50 mJ with a pulse duration of 50 μs. Air and water turned off. 320 μm thin fiber end placed into the root canal at WL-3 mm.
GIII: piezoelectric unit (mini Master, EMS, Switzerland) with ultrasonic non-cutting tip (EMS, Switzerland), placed in the canal at WL-1 mm. Ultrasonic tip and irrigation simultaneously initiated, vibrating at the endomode setting and with the flow towards the apex at approximately 30 kHz.
During retreatment: 2.5 mL of 5% NaOCl.
GI, GII, and GIII: 5 mL of EDTA (17%) for 1 min + 5 mL of NaOCl (5%) for 1 min + final washed of 15 mL of distilled water.
GIV, GV, and GVI: 5 mL of 5% NaOCl (10 s activation, 10 s rest, x6) + 17% EDTA (10 s activation, 10 s rest, x6) + 15 mL of distilled water.
In the apical third, the median debris score was 2 for Er:YAG, 2 for PIPSTM, 2 for PUI, and 3 for Nd:YAG.
In the middle third, the median score was 1.5 for Er:YAG, 2 for PIPSTM, 2 for PUI, and 2.5 for Nd:YAG.
In the coronal third, the median score was 2 for Er:YAG, 2 for PIPSTM, 2.5 for PUI, and 3 for Nd:YAG.
Neelakantan et al. (2015)
Investigation of the impact of three irrigation protocols, activated by three different methods, on mature biofilms of Enterococcus faecalis in vitro.
280 single-rooted teeth instrumented using a rotary Ni-Ti system. Biofilms of E. faecalis generated. Samples randomly divided into three experimental and one control group. CLSM was used to assess bacterial viability in situ. Root dentine powder obtained for determining the CFU. Data analyzed by appropriate statistical analyses with P = 0.05.
2940-nm Er:YAG laser (Fidelis) at 10Hz pulse rate, 50 μs pulse duration and 50mJ pulse energy, fitted with a 21- mm-long, 400 microns endodontic conical fiber tip (PIPSTM 400/14, Fotona). Tip placed into the coronal reservoir. 30 s of activation followed by a flush of new irrigant (when coronal reservoir depleted) during 6 min.
Ultrasonic files (Irrisafe, Acteon, France) in an ultrasonic generator (EMS 600 ultrasonic unit, EMS, Switzerland). 30 s of activation followed by a flush of new irrigant during 6 min.
GI: NaOCl (6%) + Etidronic acid (18%) mixed
GII: NaOCl (3%)
GIII: NaOCl (3%), EDTA (17%), NaOCl (3%)
GIV: saline (control)
After irrigation: 5 mL 2 M sodium thiosulfate for 30 s
Percentage of dead bacteria: 66.8% for UAI and 93.6% for PIPSTM, with NAOCl + Etidronic acid.
It was 54.3% for UAI and 58.9% for PIPSTM, with NaOCL + EDTA.
It was 69.3% for UAI and 89.92% for PIPSTM, with NaOCl - EDTA - NaOCl
And 1.92% for UAI and 2.97% for PIPSTM for saline.
Akyuz Ekim and Erdemir (2015)
Evaluation of the efficiency of different irrigation activation techniques on smear layer removal.
80 single-rooted human maxillary central teeth were decoronated to a standardized length. Samples prepared by using ProTaper system (Dentsply, Maillefer, Switzerland) to size F4. Teeth split longitudinally and subjected to SEM. Statistical analysis performed with SPSS.
GVI: Nd:YAG laser (Fidelis, Fotona, Slovenia) with 300-μm endodontic fiber tip used at 100 mJ repetition rate of 15 Hz (1.5 W).
GVII: pulsed Er:YAG laser (2940 nm) with 300-μm endodontic fiber tip (Fidelis, Fotona, Slovenia). Energy at 50 mJ and repetition rate of 10 Hz (0.5 W).
GVIII: Er:YAG laser (2940 nm) (LightWalker, Fotona, Slovenia) equipped with a 300-μm endodontic fiber tip (PIPSTM) using 50 ms pulse, 20 mJ at 15 Hz, (0.3 W). Tip placed into the coronal portion of root canal.
GIII: Minipiezo’s (EMS, Switzerland) at power setting ½ was used. Stainless steel ultrasonic tip (Endosoft EU, EMS, Switzerland) at WL-1 mm after each irrigation process. Irrigation and activation protocol completed at 40 s per irrigant.
GI: distilled water
GII, GIII, GIV, GV, GVI, GVII, GVIII: NaOCl (2.5%) + EDTA (17%)
6 mL of total irrigant volume and 80 s of total irrigant delivery time. After irrigation: 3 mL distilled water.
For PUI, the mean score of smear layer removal was 1.00 in the coronal third, 1.40 in the middle third, and 1.80 in the apical third.
For Nd:YAG, the mean score of smear layer removal was 1.20 in the coronal third, 1.60 in the middle third, and 2.10 in the apical third.
For Er:YAG, the mean score of smear layer removal was 1.10 in the coronal third, 1.00 in the middle third, and 2.00 in the apical third.
For PIPSTM, the mean score of smear layer removal was 0.70 in the coronal third, 1.10 in the middle third, and 1.90 in the apical third.
Sahar-Helft et al. (2015)
Comparison of the efficacy of three irrigation techniques for smear-layer removal with 17% EDTA
60 extracted single-rooted human central incisors used. Root canal preparation performed using ProTaper F3 Ni-Ti files (Dentsply, Maillefer, Switzerland) with 2.5% NaOCl irrigation. SEM used.
2940 nm Er:YAG laser (Syneron, Yokneam, Israel) equipped with a 17 mm, 400 μm plan-ended sapphire tip. Radiation was 158 ms set to 0.5 W, 50 mJ and 10 HZ for 60 s. Water spray closed.
GV: tip inserted at WL-1 mm.
GVI: tip placed in the upper coronal third of the canal.
Ultrasonic device (Suprasson Pmax, Acteon, France) at a power setting of 5, equipped with a stainless steel #25/.00 file (Irrisafe, Acteon, France).
GIII: tip placed WL-1 mm from the narrow apical part for 60 s.
GIV: tip placed in the upper coronal third of the canal for 60 s.
During treatment: 2.5% NaOCl.
GI: negative control.
GII, GIII, GIV, and GVI: 17% EDTA.
LAI (Er:YAG) + 17% EDTA is the most efficient.
Deleu et al. (2015)
Comparison of the efficacy of different irrigant activation methods in removing debris from simulated root canal irregularities.
25 straight human canine roots embedded in resin, split, and prepared to a standardized shape. A groove was cut in the wall of each canal and filled with dentin debris. Pictures (×13.6 magnification) of each groove were taken before and after each irrigation procedure using a digital camera mounted on an operating microscope (OPMI Pico). Cohen’s kappa, the Kruskal–Wallis, and the Mann–Whitney U test were used.
2.940-nm Er:YAG laser (AT Fidelis) equipped with a handpiece (R14, Fotona, Slovenia). The efficiency of the fiber is 90%; the air and water spray was turned off. 5 s of activation, four repetitions with 5-s interval.
GIV: plain 300-μm diameter fiber tip, 14 mm in length (PRECISOTM 300/14, Fotona, Slovenia). Settings: pulse energy was 60 mJ at 20 Hz and 50 μs of pulse length. Tip placed at WL-5 mm and held still.
GV: conical fiber tip, 14 mm in length (PIPSTM 300/14, Fotona). Settings: 40 mJ, 20 Hz, and pulse length of 50 μs. Tip introduced no further than 4 mm in the canal and held still.
GIII: a non-cutting #20 file (Irrisafe, Acteon, France) driven by an ultrasonic device (Suprasson Pmax, Acteon, France) at a power setting of 50% used in the canal for 20 s. The tip of the Irrisafe was kept steady WL-1 mm.
GI, GII, GIII, GIV, GV, and GVI: 2.5% NaOCl.
Each method of activation repeated 20 times.
After procedures: GII to GVI rinsed with 2-mL NaOCl (2.5%).
After activation, the percentage of debris scores of 0 was for 70% PUI, 85% for LAI, and 40% for PIPSTM.
Bago et al. (2014)
Evaluation of the antibacterial efficacy of active irrigation techniques: Er,Cr:YSGG LAI, passive ultrasonic irrigation, RinsEndo®, and conventional syringe irrigation, against intracanal Enterococcus faecalis.
100 human extracted teeth instrumented up to Protaper Universal F3 (Dentsply; Maillefer, Switzerland), sterilized in plasma, contaminated with E. faecalis, and incubated for 10 days. Presence or absence of E. faecalis checked by PCR; CFU used. The Mann–Whitney U test and Kruskal–Wallis test were used with SPSS.
GI: 2780 nm Er,Cr:YSGG laser (Waterlase, Biolase, USA) using an endodontic radial firing tip with a diameter of 275 μm and length of 25 mm (Endolase Tip RFT2, Biolase, USA) for 5 s, repeated four times in a row. Settings: power 1.25 W; pulse repetition rate 20 Hz; energy 62.5 mJ. Fiber marked at 7 mm to position it at WL-5 mm. A total of 5 mL of NaOCl was used.
GII: Piezon Master 400 (EMS), set at medium power equipped with a stainless steel 15 K-type file (Endosonore, Maillefer, Switzerland). Tip placed at WL-2 mm. 10 mL of NaOCl was continuously pumped during 60 s.
During instrumentation: 2.5% of NaOCl. Then, 1 mL of 17% EDTA for 1min, followed by 1 mL of 2.5% NaOCl and 1 mL saline solution.
GI, GII, GIII, and GIV: 2.5% NaOCl for activation.
GV (positive group): rinsed with 5 mL of sterile 0.85% saline solution
After procedures: all groups rinsed with 1 mL of 5% sodium thiosulfate for 30 s and with 1 mL of sterile saline for 30 s.
The percentage of reduction was 99.99% for both PUI and LAI.
Ordinola-Zapata et al. (2014)
Comparison of the removal of biofilm utilizing four irrigation techniques on a bovine root canal model.
50 dentine specimens (2x2 mm) infected with biofilm. Samples then adapted to previously created cavities in the bovine model. SEM used. Non-parametric tests used to evaluate for statistical significance among the groups.
GIV: 2940 nm Er:YAG laser (Fidelis, Fotona, Slovenia) was used to irradiate the root canals by using a 12 mm 400-μm quartz tip. Settings: 20 mJ per pulse, 0.30W, 15 Hz, and 50 μs pulse duration. An endodontic fiber tip (PIPSTM) placed into the coronal access opening of the access cavity. Irrigant activated for 20 s and procedure repeated 2 more times.
GIII: Irrisafe file 20.00 was used with a Satelec P5 suprasson ultrasonic unit (Acteon, France) at a power setting of 4. Tip inserted until 2 mm from the apex. Activation lasted 20 s and repeated two more times.
GI, GII, GIII, and GIV: 4 min and 4mL of 6% NaOCl.
GV: distilled water.
After procedures: 1 min with 1 mL of 5% sodium thiosulfate
The mean score was 1.52 for LAI and 1.95 for PUI.
Peters et al. (2011)
Comparison the efficacy of laser-activated and ultrasonically activated root canal disinfection with conventional irrigation, specifically its ability to remove bacterial film formed on root canal walls.
70 human premolars shaped to an apical size #20, taper .07, sterilized, and contaminated in situ with oral bacteria for 1 week and incubated for 2 more weeks. CFUs were then counted out. Histology data were not normally distributed, and 𝝌2 tests, Kruskal-Wallis, and Mann-Whitney post hoc tests were used.
GIII: 2940-nm Er:YAG laser (Fidelis, Fotona, Slovenia) at 10 Hz and 50 mJ and fitted with a 21-mm-long, 400-μm endodontic fiber. Tip placed into the coronal reservoir only and activated for 30 s. Additional irrigant deposited only in cases in which the coronal reservoir was depleted.
GII: non-cutting insert (Endosoft ESI; EMS, Switzerland) and EMS 600 ultrasonic unit used. Stainless steel inserts placed WL-1 mm short of WL, and power setting was 5/10 on the power dial.
During instrumentation: 6% NaOCl. Then 17% EDTA for 1 min followed by 6% NaOCl for 1 min. Final ultrasonic bath of 17% EDTA for 2 min.
GI, GII, and GIII =: 6% NaOCl, placed over 30 s and activated for 30 s.
After procedures: 5 mL 2 M sodium thiosulfate for 30 s.
The percentage of reduction was 98.5% for UAI and 99.5% for PIPSTM.
Peters et al. (2011)
Comparison of the efficacy of laser-driven irrigation in removing the smear layer and debriding the apical region of the root canal (the root tip) with that of ultrasonic irrigation.
40 extracted human teeth with straight single roots shaped by using hand instruments up to a size 30/.02 or a size 20/.02 file. Samples analyzed with SEM. Apical region of each specimen scored separately from reference photographs by 4 blinded evaluators by using a 5-score system. The Cohen kappa analysis, the Kruskal-Wallis, non-parametric analysis and the Mann-Whitney tests were used.
GII, GIII, and GIV: 2.780 nm Er,Cr:YSGG laser (Waterlase, MD dental laser, Biolase, USA). Settings: 1 W average power and 35 Hz. Plain fiber (quartz) tip (MZ6) with a diameter of 600 μm and length of 14 mm. The fiber tip was fixed in the handpiece. Tip submerged in the solution and made to hover above the orifice of the pulp chamber. Water spray and air switched off.
GI: stainless steel non-cutting wire size 20 (Irrisafe, Acteon, France) used, driven by a Suprasson Pmax Newtronat (Acteon, France) power setting “blue 4” (frequency, 30 kHz; displacement amplitude, approximately 30 mm) for 60 s. Tip introduced WL-2 mm.
During instrumentation: 3 mL of 3% NaOCl and 3 mL of 17% EDTA alternately between files. Then 10 mL of distilled water followed by a final rinse with 5 mL of 17% EDTA.
Activation: 17% EDTA for 30 s (GIII) or 60 s (GI, GII, and GIV).
The percentage of smear layer scores of 1 was 10% for PUI, 100% for LAI (60 s activation, 30/.02 file), 30% for LAI (30 s activation, 30/.02 file), and 50% for LAI (60 s activation, 20/.02 file). The same results were obtained for debris scores of 1.