Table 1 Characteristics of the Included Studies
Author | Study design | Intervention and type of application | Control group | Type and number of teeth | Outcome measure | Outcome measures (methods) | Exposure Volume | Exposure time | Main outcomes |
|---|---|---|---|---|---|---|---|---|---|
Quah et al. 2012 [30] (Singapore) | In-vitro | NAC 200 mg/mL (irrigation) | CH | 30 Human premolars | Microbial E. faecalis | CFU Dead cells (CLSM) | NA | 7 days | NAC (12.5 mg/mL) was significantly more efficacious in killing E. faecalis, regardless of dentin powder pre-incubation compared to CH where pre-incubation with dentin powder abolished the antibacterial effects of CH (P < .05) |
Darrag 2013 [31] (Egypt) | In-vitro | NAC 200Â mg/mL (irrigation) | G1:sterile distilled water G2: 5.25% NaOCl G3: 2% CHX | 40 Single rooted teeth | Microbial E. faecalis S. mutants | CFU CLSM | 5Â ml | 5Â min | Both planktonic bacteria were more sensitive to NAC solution recording significantly the lowest mean CFU values compared to controls. The results also showed significantly more proportion of dead cells in dual-species biofilm when NAC irrigation solution was used |
Ulusoy et al. 2015 [35] (Turkey | In-vitro | NAC 200Â mg/mL (medicament) | G1:CH 0.1% G2: CHX 2% G3: NaOCl 5.25% G4: Taurolidine 2% (medicament) | 70 Human premolars | Microbial E. faecalis | CFU SEM MTT assay | NA | 7Â days | All groups showed a good efficacy. However, CH was the strongest bactericidal agent at all test dilutions, regardless of the presence of dentin powder. The antibacterial effect of NAC and taurolidine was significantly lower than that of CH at all test dilutions |
Moon et al. 2016 [14] (Republic of Korea) | In-vitro | NAC 200 mg/mL (medicament) | G1: sterile saline G2: Saturated CH G3: 2% CHX | Hydroxyapatite (HA) disks | Microbial A. naeslundii L. salivarius S. mutants E. faecalis (Multispecies biofilm | ATP-bioluminescence SEM | NA | 10 min 24 h | The viability of mature biofilms was reduced by > 99% compared with CH or 2% CHX solution. Moreover, NAC was more efficacious in disrupting biofilm activity compared to saturated CH or 2% CHX |
Planiswary et al. 2016 [34] (India) | In-vitro | G1: NAC 200 mg/mL G2: Combination of NAC and 2% CHX (irrigation) | G1: Saline G2: 2% CHX | 16 Single rooted teeth | Microbial E. faecalis | Agar diffusion test CFU | NA | 7 days | NAC and 2% CHX showed equivalent efficacy. Maximum inhibition was shown by a combination group of NAC and 2% CHX suggesting a synergistic action which is e highly significant (P < 0.001) |
Choi et al. 2017 [37] (Republic of Korea) | In-vitro | G1: NAC 25Â mg/mL G2: NAC 50Â mg/mL G3: NAC 100Â mg/m (medicament) | G1: Saline G2: 2% CHX G3: Saturated CH | 27 Single-rooted premolars | Microbial A. naeslundii L. salivarius S. mutants E. faecalis (Multispecies biofilm | ATP-bioluminescence CFU SEM | NA | 7Â days | NAC showed better efficacy in biofilm cell removal and killing than saturated CH or 2% CHX solution. Furthermore, 100Â mg/mL NAC disrupted the mature multispecies endodontic biofilms completely |
Ridhalaksani et al. 2018 [36] (Indonesia) | In-vitro | G1: 200Â mg/mL NAC pH 2.5 G2: 200Â mg/mL NAC pH 11 (Irrigation) | G1: sterile saline G3: 2% CHX | NA | Microbial E. faecalis | CFU | NA | 1Â min | All tested groups showed good efficacy. However, NAC at pH 11 test group showed the greatest efficacy in t reducing the bacterial colonies, which was statistically significant when compared to the NAC pH 2.5 and 2% CHX groups |
Bhasin et al. 2019 [38] (India) | In-vitro | NAC 200Â mg/mL (Irrigation) | G1: 5.25% NaOCl G2: 2% CHX G3: Sterile distilled water | 40 Permanent mandibular incisors | Microbial E. faecalis S. mutans | CFU CLSM | 5Â mL | 5Â min | NAC showed significantly better efficacy compared to sodium hypochlorite (NaOCl) group, 2% chlorhexidine and sterile distilled water groups |
Singh et al. 2019 [39] (India) | In-vitro | NAC 200 mg/mL (Irrigation) | G1: Sterile distilled water G2: 2% CHX | 60 Maxillary incisors | Microbial E. faecalis S. mutans | CFU | 5 ml | 5 min | NAC was significantly more efficacious than sterile distilled water and 2% CHX (P < 0.01) |
Abu Hasna et al. 2020 [40] (Brazil) | In-vitro | G1: NAC G2: NAC + PDT (medicament) | G1: Saline G2: CH G3: PDT | 80 Single rooted teeth | Microbial E. faecalis | CFU CLSM SEM | NA | NA | NAC is as effective as CH regardless of its combination with PDT |
Alireza et al. 2021 [41] (Iran) | In-vitro | G1: NAC G2: CH + 5% NAC G2: 50% CH + 50% NAC (medicament) | G1: CH G2: DS 100 µg G3: CH + 5% DS G4: 50% CH + 50% DS | 35 Single rooted mandibular premolars | Microbial E. faecalis | CFU | NA | 7 days | All tested agents showed a good antibacterial activity compared to saline at both depths, i.e. 100 and 200 µm. NAC showed an antibacterial efficacy comparable to that of CH. However, both NAC and CH were inferior to DS |
Karapinar et al. 2016 [33] (Turkey) | In vitro | NAC (medicament) | CH | Cell lines | LPS- induced Inflammatory mediators (TNF-α protein and mRNA, TGF-b1) | ELISA and qRT-PCR | 5, 10, 20, and 40 mM | 24 h | Equivalent anti-inflammatory efficacy of NAC and CH in reducing TNF-α |
Corazz et al. 2021 [32] (Brazil) | Randomized clinical trial | NAC (medicament) | G1: CH + saline G2: CH + 2% CHX | 36 Teeth with endodontic infection (32 anterior & 4 premolars) | Immunoresolvents, (Resolvins E1, D1) | ELISA | NA | 14 days | NAC significantly increased RvE1 and RvD2 in apical periodontitis after 14 days of treatment in comparison to CH |
Silveira 2013 [42] (Spain) | In-vitro | NAC 100 mg mL combination with alexidine (2%–0.007 8%) | Alexidine alone | Isolated from a failed endodontic treatment | Microbail E. faecalis | CFU | NA | 1–5 min | All two groups showed similar result with not statistically significant |
Khosravi 2018 [43] (Iran) | In-vitro | G1: Ciprofioxacin and NAC G2: levofloxacin and NAC | G1: normal saline G2: CH G3: ciprofloxacin G4: levofloxacin | 120 Humans extracted teeth with single canals | Microbial E. faecalis | RCC SEM | NA | 1 Week | All intracanal medicaments were significantly more effective than calcium hydroxide (P < 0.05). The combination of levofloxacin and NAC caused significantly higher reduction in colony count in comparison with other tested medicaments (P = 0.001) |