how often do you visit your dentist?have you got your teeth checked for decay or calculs deposits?
the black dot may be either due to plaque
qnd food debris accumulation.this will result in a heavy band of black calcific deposits called calculus.or it can be stains too.
deep scaling and polishing will remove this.
if there is dental caries
,which can be felt by probing,then it should be restored using suitable filling materials .if the dacay is deep,apply dycal and then glass ionomer or composite resin.
always brush your teeth twice daily using soft toothbrush and dental floss.
wash your mouth after every meals.
get a check up in every 6 months.
use chlorhexidine gluconate
containing mouthwash to prevent accumulation of micro-organisms.