confocal microscopy human 21 Microscopy, Confocal 17 Article 16 Humans 16 controlled study 12 nonhuman 11 procedures 11 Animals 9 animal 9 in vitro study 9 mouse 8 In Vitro Techniques 7 Mice 7 metabolism 7 drug effect 6 surface property 6 Surface Properties 5 animal experiment 5 diagnostic imaging 5 fluorescence microscopy 5 human cell 5 physiology 5 animal tissue 4 apoptosis 4 chemistry 4 cytology 4 flow cytometry 4 scanning electron microscopy 4 tooth disease 4