You need to restore your baby's teeth because he is 3 yr old only. Permanent teeth start coming in age of 6 and all permanent teeth erupt till age of 12-13.(except last molar). If he loss teeth very early, their will be I'll effect on his health. He will be not able to have food properly. Also if primary removed or loss early the permanent teeth erupt in wrong places.
Next Steps
consult dentist, and go through proper treatment to save all the decayed teeth.
Health Tips
Show your kid some videos on oral health or you can down load app to play dentist game. Do something to motivate your kid.