Streptococci causing dental caries :
Strep. mutans:

It is member of viridans streptococci ( α hemolytic).
It assumes bacillary form in acid environment.
Can synthesize acid and large polysaccharide (adhesive dextran or levan) from sucrose.
Streptococci equisimilis
Streptococci mutans
Streptococci pneumoniae
Streptococci bovis