Table 1. Studies included in this systematic review: characteristics according to PICOS approach.
| Author | Participants | Intervention | Control | Outcome | Study Design |
|---|---|---|---|---|---|
| Gupta P, et al. (2019) [39] |
· Adults (≥ 18 y.o.) · MDAS 19-25 · n = 60 (30/group) |
Slow induction (max: 50% N2O) |
Local anesthesia alone | MDAS (< 19): · NOOS: 100.0% · Control: 96.7% |
N. I. on blinding, Parallel groups |
| Samir PV, et al. (2017) [40] |
· Children (5-12 y.o.) · Frankl 3-4 · n = 60 (30/group) |
Slow induction (max: 40% N2O) (NOOS 1) |
Rapid induction, adjustable proportions (max: 40% N2O) (NOOS 2) | RASS (≤ -2): · NOOS 1: 100.0% · NOOS 2: 100.0% |
N.I. on blinding, Parallel groups |
| Subramaniam P, et al. (2017) [41] |
· Children (5-10 y.o.) · Anxious, potentially cooperatives · n = 60 (30/group |
Slow induction (max: 40% N2O) |
Oral triclofos sodium (70 mg.kg-1) | Houpt, pt. IV (≥ 3): · NOOS: 83.3% · Control: 90.0% |
Non-blinded, Parallel groups |
| Takkar D, et al. (2015) [42] |
· Children (7-10 y.o.) · Frankl 2-3 · n = 40 (20/group |
Slow induction (max: 40% N2O) |
Placebo (O2 100%) | Double-blind, Parallel groups | |
| Allen M, Thompson S. (2014) [43] |
· Adults (18-62 y.o.) · Anxious, potentially cooperatives · n = 40 (NOOS: 19; Control: 21) |
Slow induction (max: 40% N2O) |
Sevoflurane (max: 0.3%) | Single-blind, Parallel groups | |
| Guelmann M, et al. (2012) [44] |
· Children (5-8 y.o) · Anxious, potentially cooperatives · n = 17 |
Rapid induction, adjustable proportions (max: 50% N2O) | Placebo (O2 100%) | OSUBRS (< 3) · NOOS: 100.0% · Control: 94.1% |
Double-blind, Cross-over |
| Zhang G, et al. (2012) [45] |
· Adults (18-42 y.o.) · DAS-R 9-12 · n = 38 |
Rapid induction, fixed proportions (30% N2O) |
Video-eyewear + 30% N2O | Houpt, pt. IV (≥ 3): · NOOS:100.0% · Control: 100.0% |
Non-blinded, Cross-over |
| Özen B, et al. (2012) [46] |
· Children (4-6 y.o.) · Frankl 1-2 · n = 240 (60/group) |
Rapid induction, fixed proportions (50% N2O) |
· 1: Intranasal midazolam (0.20 mg.kg-1) + 50% N2O · 2: Oral midazolam (0.75 mg.kg-1) + 50% N2O · 3: Oral midazolam (0.50 mg.kg-1) + 50% N2O |
Treatment completion: · NOOS: 55.0% · Control 1: 86.6% · Control 2: 78.3% · Control 3: 71.6% |
N.I. on blinding, Parallel groups |
| Abdullah WA, et al. (2011) [47] |
· Adults (18-30 y.o.) · DAS-R 9-14 · n = 20 |
Slow induction (max: 50% N2O) |
Methoxyflurane (max: 0.4%) | RSS (≥ 2): · NOOS: 100.0% · Control: 100.00% |
Non-blinded, Cross-over |
| Soldani F, et al. (2010) [48] |
· Children (6-15 y.o.) · Anxious, potentially cooperatives · n = 29 |
Slow induction (max: 30% N2O) |
Sevoflurane (max: 0.3%) | Treatment completion: · NOOS: 89.7% · Control: 89.3% |
Double-blind, Cross-over |
| Baygin O, et al. (2010) [49] |
· Children (5-8 y.o) · Frankl 1-2 · n = 60 (15/group) |
Slow induction (max: 40% N2O) |
· 1: Oral hydroxyzine hydrochloride (1 mg.kg-1) + 40% N2O · 2: Oral midazolam (0.70 mg.kg-1) + 40% N2O · 3: Oral ketamine (3 mg.kg-1) + oral midazolam (0.25 mg.kg-1) + 40% N2O |
RSS (≥ 2): · NOOS: 66.7% · Control 1: 66.7% · Control 2: 74.0% · Control 3: 66.7% |
Double-blind, Parallel groups |
| Wilson KE, et al. (2007) [50] |
· Children (10-15 y.o.) · Anxious, potentially cooperatives · n = 36 |
Slow induction (max: 30% N2O) |
Transmucosal midazolam (0.2 mg.kg-1) | Houpt, pt. IV (≥ 3): · NOOS: 100.0% · Control: 100.0% |
Non-blinded, Cross-over |
| Wilson KE, et al. (2006) [51] |
· Children (5-10 y.o.) · Anxious, potentially cooperatives · n = 35 |
Slow induction (max: 30% N2O) |
Oral midazolam (0.3 mg.kg-1) | Houpt, pt. IV (≥ 3): · NOOS: 100.0% · Control: 100.0% |
Non-blinded, Cross-over |
| Wilson KE, et al. (2003) [52] |
· Children (12-16 y.o.) · Anxious, potentially cooperatives · n = 40 |
Slow induction (max: 30% N2O) |
Intravenous midazolam (max: 5.0 mg) | Houpt, pt. IV (≥ 3): · NOOS: 97.5% · Control: 95.0% |
Non-blinded, Cross-over |
| Wang CY, et al. (2002) [53] |
· Adults (19-43 y.o.) · Anxious, potentially cooperatives · n = 17 |
Slow induction (max: 50% N2O) |
Sevoflurane (max: 1%) | VAS (≤ 3): NOOS: 100.00% Control: 100.00% |
Single-blind, Cross-over |
| Wilson KE, et al. (2002, a) [54] |
· Children (10-16 y.o.) · Anxious, potentially cooperatives · n = 44 |
Slow induction (max: 30% N2O) |
Oral midazolam (0.5 mg.kg-1) | Houpt, pt. IV (≥ 3): · NOOS: 97.7% · Control: 97.7% |
Non-blinded, Cross-over |
| Wilson KE, et al. (2002, b) [55] |
· Children (10-16 y.o.) · Anxious, potentially cooperatives · n = 26 |
Slow induction (max: 30% N2O) |
Oral midazolam (0.5 mg.kg-1) | Houpt, pt. IV (≥ 3): · NOOS: 96.1% · Control: 96.1% |
Non-blinded, Cross-over |
| Lahoud GY, Averley PA. (2002) [13] |
· Children (3-10 y.o.) · Dedicated clinic for anxiety management · n = 411 (NOOS: 170, Control: 241) |
Rapid induction, fixed proportions (40% N2O) | Sevoflurane (max: 0.3%) | Treatment completion: · NOOS: 52.3% · Control: 89.2% |
Non-blinded, Parallel groups |
| Rodrigo MR, Rosenquist JB. (1988) [56] |
· Adults (18-31 y.o.) · Anxious, potentially cooperatives · n = 20 |
Rapid induction, fixed proportions (33% N2O) | Isoflurane (max: 0.5%) | Custom scale: · NOOS: 100.0% · Control: 100.0% |
Double-blind, Cross-over |
DSTG, Sedation Score from Dental Sedation Teachers Group; Houpt, Houpt Behaviour Rating Scale; MDAS, Modified Dental Anxiety Scale; N2O, Nitrous Oxide; O2, Oxygen; OAA/S, Observer’s Assessment of Alertness/Sedation; OSUBRS, Ohio State University Behavioral Rating Scale; RASS, Richmond Agitation-Sedation Scale; RSS, Ramsay Sedation Score; VAS, Visual Analogue Scale.