Table 2.

Results of Cochrane Collaboration’s tool for assessing the risk of bias.

Study (Author, Year)	Sequence Generation	Allocation Concealment	Blinding	Incomplete Outcome Data	Selective Outcome Reporting	Other Bias
Altenau, 2017 [10]
Ayatollahi, 2014 [11]
Hassan, 2014 [12]
Ozmete, 2016 [13]
Prasanna, 2010 [14]
Soltani, 2015 [15]
Towers, 2018 [16]

Key: low risk of bias; high risk of bias; unclear risk of bias.