colony forming unit Article 20 controlled study 17 nonhuman 16 human 12 Humans 10 microbiology 7 chemistry 6 drug effect 6 antibacterial activity 5 cell viability 5 male 5 Escherichia coli 4 Male 4 Staphylococcus aureus 4 bacterial colonization 4 bacterium culture 4 cell proliferation 4 human cell 4 physiology 4 Animals 3 Antimicrobial activity 3 Bacillus subtilis 3 Biofilms 3 Candida albicans 3 Female 3 Streptococcus mutans 3 Time Factors 3 Titanium 3 animal 3