Table 5.

Annotation of the quality classification modified according to Shabazfar et al. [69]

Scale	Criterion	Meaning of criterion	Score
Journal	“Peer review”	Increased result validity through peer review	Simple
Study design	Randomization	Random allocation of the subjects?	Double
	Investigation of established hypotheses	Have hypotheses been made and answered?	Double
Measurement tools	Suitable measuring instrument	Objectifiable measurements?	Simple
Patients	Objective comparison of two consumables	Possible comparison of subjects?	Simple
	Number	Sufficient patient number? (> 35)	Simple
Results	Adequate level of data aggregated	Have results been compiled appropriately?	Simple
	Investigator	Number of investigators mentioned? How many?	Simple