id	keyword
dentistry3000-89	mta
dentistry3000-89	root
dentistry3000-89	materials
dentistry3000-89	filling
dentistry3000-89	end
dentistry3000-89	study
dentistry3000-89	surface
dentistry3000-89	calcium
dentistry3000-89	pmid
dentistry3000-89	angelus
dentistry3000-89	samples