The area of 3rd molar is having white specks is opercular flap which is covering the part of tooth surface with some space in between the tooth & tissue surface (which you called as small hole) .
This space lodges food & might be causing discomfort. So maintain proper oral hygiene.
Next Steps
visit dentist / periodontist .
Health Tips
Gargle with lukewarm salt water after every meals to maintain oral hygiene