If dental drill enter in gum or toung.it cause any viral infection .if it is not proper sterilized?

It can cause viral or bacterial infection if the drill bit is contaminated with any micro-organisms. Your dentist should be sterilizing instruments between patients. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs.

Greater risk bacterial than viral. However all instruments should be properly sterilized. If concerned talk over sterilization techniques with your Dentist.

ANY DENTAL INSTRUMENT THAT ENTERS THE MOUTH CAN CAUSE AN INFECTION IF NOT PROPERLY STERILIZED.ASK OR LOOK AROUND THE OFFICE FOR AN AUTOCLAVE MACHINE THAT STERILIZES INSTRUMENTS AND THAT THE INSTRUMENTS ARE IN A STERILE BAG THAT IS OPENED IN YOUR PRESENCE BEFORE BEING USED ON YOU.