Table 3 Characteristics of the included studies exploring the removal of microbes
Study (year) | Sample size per group | Sample types | Apical preparation size | Para-meters of UAI tips | Power of ED | Placement of tips | Volume and concentration of activatied irrigants and activation time | Evaluation methods | Main results | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bacterial species | Culture time in canals | Sampling | Examination | Â | ||||||||
Eneide et al. (2019) [47] | 12 | Single-rooted human teeth | 25 / 06 | NM | 6 kHz | WL-1 mm | 6 ml 5.25% NaOCl 6 ml 17%EDTA 20 s × 6 | Enterococcus faecalis | 28 days | A canal brush scratching canal walls | Colony forming units | No significant differences between UAI and ED |
Hage et al. (2019) [48] | 10 | Single-rooted lower premolars | 25 / 08 | 15 / 02 40 kHz | 6 kHz | WL-1 mm | 9 ml 5.25% NaOCl 30 s × 3 | E. faecalis | 7 days | A paper point obtaining liquid | Colony forming units | No significant differences between UAI and ED |
Hoedke et al. (2021) [50] | 20 | Straight canals of upper anterior teeth | Exp 1: infection in 25 / 06 canals and subsequent preparation to 40 / 06 Exp 2: 40 / 06 | 25 / 00 30 kHz | 6 kHz | WL-1 mm | Protocol 1: 10 ml 0.9% NaCl 30 s × 2 Protocol 2: 10 ml 1% NaOCl 30 s × 2 | E. faecalis and Streptococcus oralis | Before irrigation: 5 days After irrigation: 5 days | Sample 1: a paper point obtaining liquid Sample 2: a Hedström file scratching canal walls | Colony forming units | Exp 1: No significant differences between UAI and ED Exp 2: Signifi-cantly greater bacterial reduction by ED than UAI |
Neuhaus et al. (2016) [21] | Exp 1: 5 straight (< 15°) roots and 5 curved (> 25°) roots per group Exp 2: 6 | upper premolars and front teeth, and palatal roots from upper molars | 25 / 08 | NM 20% power | 6 kHz | UAI: WL-1 mm ED: WL | Exp 1: NM 0.9% NaOCl 20 s × 3 Exp 2: NM 1.5% NaOCl 20 s × 3 | 1. Streptococcus gordonii 2. Actinomyces oris 3. Fusobacterium nucleatum 4. S. gordonii and A. oris 5. S. gordonii and F. nucleatum 6. E. faecalis 7. Candida albicans 8. Clinical retreatment isolates (1–3 and 8 just for Exp 1; 4–7 for both Exp 1 and 2) | Exp 1: 3 days Exp 2: 21 days | A paper point obtaining liquid | Colony forming units | Exp 1: significantly less remaining micro-organisms by ED than UAI in both straight and curved canals Exp 2: both ED and UAI were less effective against E.faecalis and C.albicans |
Swimberghe et al. (2021) [54] | 20 | Acrylic models with curved (30° or 45°) canals | 40 / 06 | 25 / 00 30 kHz | 6 kHz | UAI: WL-2 mm ED: WL-1 mm | Water 20 s × 3 | Area of the biofilm-mimicking hydrogel in the apical grooves recorded by a digital camera and calculated in pixels | 30° group: No significant differences 45° group: significantly more hydrogel removed by UAI than ED | |||
Yared et al. (2020) [56] | 10 | Single-rooted lower premolars | 25 / 08 | 20 / 02 power 4 | NM | WL-1 mm | Exp 1: NM 5.25%NaOCl at room temperature 20 s × 3 Exp 2: NM 5.25%NaOCl heated by 150℃ heat carrier 20 s × 3 | E. faecalis | 28 days | #15 hand file scratching canal walls, then a paper point obtaining liquid | Colony forming units | No significant differences between UAI and ED in exp 1 or exp 2 |