Table 2 Characteristics of the included studies exploring the removal of smear layer, debris and soft tissue
Study (year) | Sample size per group | Sample types | Apical preparation size | Parameters of UAI tips | Power of ED | Placement of tips | Volume and concentration of activatied irrigants and activation time | Research indications | Obser-vational sites | Evaluation methods | Main results |
|---|---|---|---|---|---|---|---|---|---|---|---|
Al-Rujaib et al. (2022) [63] | 20 | Single canals of lower premolars | 40 / 06 | 25 / 00 30 kHz | 6 kHz | WL-2 mm | 10 ml 5.25%NaOCl 5 ml 17%EDTA 60 s × 3 | Smear layer and debris | Coronal Middle Apical | SEM analysis 400 × magnifi-cation for debris 1000 × for smear layer 5-grade scoring system | Significant-ly less debris at apical thirds and less smear layer at all thirds in ED than UAI |
Haupt et al. (2020) [49] | 20 | Curved (20°-40°) mesiobuccal canals of lower molars | 40 / 04 | 15 / 02 30 kHz | 5 kHz | WL-1 mm | 6 ml 5%NaOCl 20 s × 3 | Smear layer and debris | Coronal Apical | SEM analysis 200 × magnifi-cation for debris 1000 × for smear layer 5-grade scoring system | No significant differences between UAI and ED |
Plotino et al. (2021) [52] | 10 | Straight (< 10°) single round canals of single-rooted teeth | 40 / 06 | 15 / 00 30 kHz | 5 kHz | WL-1 mm | 3 ml 5%NaOCl 20 s × 3 Exp 1: activated after instrumen-tation Exp 2: activated during and after instrumentation | Smear layer and debris | Coronal Middle Apical | SEM analysis 1000 × magnifi-cation for smear layer and debris 4-grade scoring system | No significant differences between UAI and ED |
Urban et al. (2017) [55] | 12 | Single round canals of lower premolars | 40 / 06 | 15 / 00 30 kHz | 6 kHz | WL-1 mm | 3%NaOCl 30 s × 3 | Smear layer and debris | Coronal Middle Apical | SEM analysis 200 × magnifi-cation for debris 1000 × for smear layer 5-grade scoring system | No significant differences between UAI and ED |
Zhang et al. (2021) [45] | 15 | Straight (< 10°) single canals of lower premolars | 40 / 06 | 25 / 02 NM | 6 kHz | WL-2 mm | 3 ml 17%EDTA 3 ml 3%NaOCl 30 s × 2 | Smear layer | Coronal Middle Apical | SEM analysis 1000 × magnifi-cation for smear layer 5-grade scoring system | No significant differences between UAI and ED |
Linden et al. (2020) [22] | 9 | Curved mesial canals connected by an isthmus of lower molars | 30 / 07 | 20 / 00 45% of the maximum power (‘yellow 9’) | 6 kHz | WL-2 mm | 3 ml 2.5%NaOCl 20 s × 3 | Debris | Canals and isthmus | Percentage of debris reduction evaluated by micro-CT voxel size of 12 µm | Significant-ly more debris removed by UAI than ED |
Rödig et al. (2019)[24] | 10 | Curved (10°-25°) Vertucci II mesial canals of lower molars | 25 / 08 | 25 / 00 30 kHz | 6 kHz | WL-2 mm | 5 ml 1%NaOCl 2 ml 17%EDTA 20 s × 4 | Debris | Canals and isthmus | Percentage of debris reduction evaluated by micro-CT voxel size of 10.5 µm | No significant differences between UAI and ED |
Rodrigues et al. (2021)[53] | 8 | Curved (20°-46°) Vertucci I mesial canals of lower molars | 25 / 08 | 15 / 02 medium power | 6 kHz | UAI: WL-2 mm ED: WL-1 mm | 10 ml 5%NaOCl 5 ml 17%EDTA 20 s × 3 | Debris | Canals and isthmus | Percentage of debris reduction evaluated by micro-CT voxel size of 12.8 µm | No significant differences between UAI and ED |
Alsubait et al. (2021) [46] | 14 | Curved (10°-25°) mesial canals with isthmus of lower molars | 30 / 09 | 20 / 00 power 8 | 6 kHz | WL-1 mm | 2 ml NM NaOCl 30 s × 3 | Debris | 3 mm and 5 mm from the apex | Percentage of debris reduction evaluated by a stereomicroscope at 50 × magnifi-cation | No significant differences between UAI and ED |
Al-Jadaa et al. (2023) [62] | 9 | Resin blocks with 2 canals connected by an isthmus containing artificial debris | 45 / 05 | 25 / NM 38 kHz | 6 kHz | 2 mm from the apical foramen | 1 ml 1.3%NaOCl 20 s × 3 | Debtis | Isthmus | Cleared surface area in the isthmus recorded by a camera | No significant differences between UAI and ED |
Plotino et al. (2019) [23] | Tests repeated 10 times per group | Canal resin models with 3 circular cavities | 2.5 mm / 00a | Group 1: 15 / 02 40 kHz Group 2: 15 / 02 28-36 kHz Group 3: 15 / 00 28-36 kHz | 6 kHz | WL-1 mm | Exp 1: NM 5%NaOCl 20 s × 3 Exp 2: NM 17%EDTA 20 s × 3 | Debris | Coronal, middle and apical semi-circles | Percentage of debris reduction evaluated by a digital camera | Significant-ly more debris removed by ED than all UAI groups |
Conde et al. (2017) [12] | 10 | Maxillary central incisors | 30 / 06 | 20 / 00 power 4 | NM | WL-2 mm | 3 ml 2.5%NaOCl 1 ml 17%EDTA 30 s × 2 | Soft tissue | Artificial grooves at WL-2 mm and WL-6 mm | Percentage of weight reduction of pigs' palatal mucosa in the grooves | No significant differences between UAI and ED |
Iandolo et al. (2021) [51] | Tests repeated 20 times per group | An upper single-rooted premolar with two root canals and an isthmus | 25 / NM | 15 / 02 40 kHz | 6 kHz | WL-1 mm | Exp 1: 10 ml NM NaOCl 30 s × 10 Exp 2: 10 ml NM heated NaOCl 30 s × 10 | Soft tissue | Isthmus | Area of pulp tissue after irrigation recorded by a digital camera and calculated in pixels | No significant differences between UAI and ED in exp 1 or exp 2 |