id	keyword
bjos-8641900	root
bjos-8641900	smear
bjos-8641900	dentin
bjos-8641900	layer
bjos-8641900	surface
bjos-8641900	acid
bjos-8641900	tetracycline
bjos-8641900	periodontal
bjos-8641900	study
bjos-8641900	calculus