Table 5.

Evaluation of included studies according to Cochrane Risk of Bias Tool for Randomized Controlled Trial.

	Bruno et al. 2021 [21]	Dai et al. 2019 [25]	Garino et al. 2016 [29]	Kravitz et al. 2008 [33]
Random sequence generation	LOW	SOME CONCERNS	LOW	LOW
Allocation concealment	LOW	HIGH	LOW	SOME CONCERNS
Blinding of participants and personnel	HIGH	HIGH	HIGH	HIGH
Blinding of outcome assessment	SOME CONCERNS	HIGH	SOME CONCERNS	HIGH
Incomplete outcome data	LOW	LOW	LOW	LOW
Selective reporting	LOW	LOW	LOW	HIGH
Other bias (why)	The bias comes from the difference between the bonding procedure and analyzing the data, as the templates and attachments differ from each other	Great loss to follow-up	The bias comes from the difference between the bonding procedure and analyzing data, as attachments are noticeable in the mouth	The pretreatment model was obtained by the indirect and direct methods, resulting in an uneven level of accuracy.
Risk of bias judgement	SOME CONCERNS	HIGH	SOME CONCERNS	HIGH