Table 2.

Search data, search strategies and number of results for each database.

Database	Search strategies	Results	Selected papers
Cochrane C.R.C. Trials	conventional OR self-ligating	160	2
Ovid ALL EMB Reviews	exp Orthodontic Appliances / OR edgewise.mp. AND exp Orthodontic Appliance Design/ OR exp Orthodontic Brackets/ OR self-ligating.mp. OR exp Orthodontic Appliances/ AND biofilm.mp. OR exp Dental Biofilm Index/ AND streptococcus mutans.mp. OR exp Streptococcus mutans/	53	4
PubMed (NLM)	conventional AND self-ligating, OR biofilm OR Streptococcus mutans	788	5
Bireme	conventional OR self-ligating	400	1
TOTAL		1,401	12