Table 4.

Obtained data and meta-analysis on enamel wear loss.

Author and Year	Sample	Measured at	Mean Value
West et al. 2019 [33]	36 Intraoral appliances with human enamel sample	Day 10	0.097 µm vs. 1.495 µm
Ionta et al. 2019 [37]	256 Bovine enamel blocks	Day 5	4.8 ± 2.5 µm vs. 4.8 ± 1.4 µm
West et al. 2017 [43]	33 Intraoral appliances with human enamel sample	Day 15	1.60 µm vs. 5.03 µm
West et al. 2017 [44]	33 Human enamel specimens	Day 15	5.75 µm vs. 23.75 µm
Hove et al. 2014 [50]	16 Intraoral appliances with human molar	Day 9	14.5 ± 9.3 µm and 33.3 ± 7.4 µm and 0.4 ± 1.3 µm vs. 29.2 ± 10.5 µm
Bellamy et al. 2014 [51]	12 intraoral appliances with human enamel sample	Day 15	2.03 µm vs. 15.53 µm
Stenhagen et al. 2013 [53]	16 intraoral appliances with molar sample	Day 9	1.8 ± 1.9 µm vs. 26.3 ± 4.7 µm vs. 3.1 ± 4.8
Huysmans et al. 2011 [57]	20 intraoral appliances with human enamel sample	Day 5	data not clear or incomplete