Table 3. Descriptive Data Related to Smear Layer Removal Effect .
| Author | Study objects | Ni. of teeth | MAF | Laser tip | Laser settings (pulse energy, repetition rate, power, pulse widths) | Activation time | EDTA | Main findings |
| George60 (2008) | LAI (Er:YAG, Er,Cr:YSGG) | 150 | 50/0.05 | Er:YAG, Er,Cr:YSGG: 400 μm, n/a | Er:YAG: 200 mJ, 20 Hz, 4 W, n/a Er,Cr:YSGG: 62.5 mJ, 20 Hz, 1.25 W, n/a |
50 s | 15% EDTAC | Conical fibers performed better than plain fibers, no difference between 2 laser systems |
| DiVito20 (2011) | PIPS | 50 | K-file #30 30/0.06 |
400 μm, 14 mm | 20 mJ, 10 Hz, 0.2 W, 50 μs | 20 s, 40 s | 17% | PIPS removed more smear layer with EDTA than with saline and saline alone |
| DiVito19 (2012) | PIPS | 80 | 30/0.06 | 400 μm, 12 mm | 20 mJ, 15 Hz, 0.3 W, 50 μs | 30 s | 17% | PIPS removed more smear layer with EDTA than with saline and saline alone |
| Zhu43 (2013) | PIPS, CI | 48 | 40/0.06 | 400 μm, 12 mm | 20 mJ, 15 Hz, 0.3 W, 50 μs | 60 s | PIPS: 3% NaOCl, CI: 3% NaOCl +17% EDTA | PIPS removed the smear layer similarly to CI |
| Sathe49 (2014) | PIPS, LAI (Nd:YAG), MAI | 30 | 30/0.09 | PIPS: 400 μm, 12 mm LAI: 200 μm,n/a |
PIPS: 40 mJ, 20 Hz, n/a, 50 μs LAI: n/a, 15 Hz, 1.5 W, 50 μs |
PIPS: n/a LAI: 3x5 s NaOCl, 3x5 s EDTA |
17% EDTA 5.25% NaOCl |
PIPS removed more smear layer than LAI, MAI |
| Guidotti54 (2014) | LAI, CI | 48 | 30/0.09 | 300 μm, n/a | 50 mJ, 20 Hz, 1 W, n/a | 3x5 s NaOCl; 3x5 s NaOCl + 3x5 s EDTA; 3x5 s EDTA | 2.5% NaOCl 17% EDTA |
The LAI with NaOCl+EDTA group gave better results than NaOCl alone activated, EDTA alone activated and EDTA alone non-activated groups |
| Akyuz Ekim52(2015) | PIPS, LAI (diode laser, Nd:YAG, Er:YAG), ANP, PUI, CI | 80 | 40/0.06 | PIPS, LAI: 300 μm, 17 mm |
LAI: diode laser (n/a, 15 Hz, 1.5 W, n/a), Nd:YAG (100 mJ, 15 Hz, 1.5 W, n/a), Er:YAG (50 mJ, 10 Hz, 0.5 W, n/a) PIPS: 20 mJ, 15 Hz, 0.3 W, 50 μs |
20 s | 17% | PIPS removed more smear layer than CI and the diode laser, similarly to the rest |
| Sahar-Helft50 (2015) | LAI (Er:YAG), PUI, CI | 60 | 30/0.09 | 400 μm, 17 mm |
50 mJ, 10 Hz, 0.5 W, n/a | 60 s | 17% | LAI removed more smear layer than PUI and CI |
| Arslan55 (2016) | PIPS, LAI (Er:YAG), SI, CI | 64 | 40/0.06 | LAI: 300 μm, n/a PIPS: 400 μm, n/a |
LAI: 50 mJ, 20 Hz, 1 W, n/a PIPS: 20 mJ, 15 Hz, 0.3 W, n/a |
3x20 s | QMix | PIPS performed similarly to SI, both were better than CI |
| Ayranci51 (2016) | LAI (Er:YAG), PUI | 48 | 40/0.06 | 300 μm, 14 mm | n/a, n/a, n/a, 50 ms | 60 s | 17% | LAI removed more smear layer than PUI |
| Nasher59 (2016) | PIPS, CI | 64 | 40/n/a | 600 μm, 9 mm | 20 mJ, 50 Hz, 0.3 W, 50 μs | 2x30 s | 20% | PIPS performed similarly to CI |
| Keles30 (2016) | PIPS, LAI (Er:YAG, Nd:YAG), PUI, SAF, CI | 90 | 45/n/a | PIPS, Er:YAG: 300 μm, 14 mm Nd:YAG: 320 μm, n/a |
PIPS: 45 mJ, 20 Hz, 0.9 W, 50 µs LAI: 50 mJ, 20 Hz, 1 W, 50 µs |
PIPS, LAI: 3x10 s NaOCl + 3x10 s EDTA PUI, SAF: 60 s EDTA + 60 s NaOCl |
5% NaOCl 17% EDTA |
All other methods were more effective than CI. The Er:YAG LAI group had the least amount of residual smear layer |
| Suman57 (2017) | LAI (Er:YAG), SI, ANP, CI | 40 | 40/0.06 | 300 μm, n/a | 50 mJ, 10 Hz, 0.5 W, n/a | LAI: 3x15 s EDTA + 3x15 s NaOCl SI: 60 s EDTA + 60 s NaOCl |
5.25% NaOCl 17% EDTA |
ANP was significantly more effective than all other groups in the apical third. |
| Turkel26 (2017) | PIPS, ANP, CI | 142 | 40/0.06 | 300 μm, 14 mm |
20 mJ, 15 Hz, 0.3 W, 50 μs | 30 s NaOCl + 30 s EDTA | 5% NaOCl 17% EDTA |
PIPS performed similarly to ANP and CI |
| Mancini56 (2017) | LAI (Er:YAG), PUI, ANP, SI | 80 | 40/0.06 | 300 μm, 14 mm |
60 mJ, 20 Hz, n/a, 50 μs | LAI: 4x5 s NaOCl PUI, SI: 60 s NaOCl |
5.25% NaOCl | ANP was the most effective at 1 mm from apex; SI was more effective than PUI, LAI at 3, 5, and 8 mm from apex |
| Gorus53 (2018) | LAI (Er:YAG), CI | 60 | 30/0.09 | n/a | 20/40 mJ, 15 Hz, 0.3/0.6 W, n/a | LAI: 2x3 s NaOCl SI: 60 s NaOCl |
5% NaOCl | LAI removed more smear layer than CI; no difference between parameters |
| Ozbay58 (2018) | PIPS, LAI (Nd:YAG, Er,Cr:YSGG), CI | 96 | 40/0.06 | PIPS: 300 μm, n/a Nd:YAG: 320 μm, n/a Er,Cr:YSGG: 300 μm, n/a |
PIPS: 20 mJ, 15 Hz, 0.3 W, n/a Nd:YAG: 60 mJ, 15 Hz, 1.5 W, n/a Er,Cr:YSGG: n/a, 20 Hz, 1.5 W, 140 ms |
8x5 s distilled water 4x5 s NaOCl + 4x5 s EDTA |
2.5% NaOCl 17% EDTA |
Lasers were more effective than CI; no difference between laser systems |
CI, conventional irrigation; LAI, laser-activated irrigation; MAF, master apical file; n/a, not available; MAI, manual activated irrigation; ANP, apical negative pressure; PIPS, photon-induced photoacoustic streaming; PUI, passive ultrasonic irrigation; SAF, self-adjusting file; SI, sonic irrigation; UAI, ultrasonically activated irrigation.