[Sponsored Feature] As a part of Healthy Mouth Happy Life, a campaign by NDTV - Listerine to spread awareness on the importance of oral health and ways to maintain a healthy mouth, we speak with Dr Shalini Dua, Dental Surgeon, Founder & MD Sanare Medical PVT. LTD to know about the causes of cavities and how one can prevent it from developing. Here's what she said.