Dr DeMello grew up in Lincoln and graduated from Lincoln High School, achieved his B. A. from  Boston University, and a Master of Arts degree in Experimental Biology at Boston University doing bone marrow stem cell research where he co-authored six studies on bone marrow stem cell transplantation that were published in scientific research journals.

He graduated from the School of Dentistry at Georgetown University in 1981 where he achieved his DDS and has practiced dentistry in Lincoln ever since.  He is an active member of the American Dental Association, the Rhode Island Dental Association having served on the Peer Review Committee, the Children's Dental Health Committee, Access to Dental Health Committee, and the Legislation Committee.  He is a past president of the Pawtucket Dental Society and served on the RI State Governors Committee to Reorganize Medical Assistance in 1992. He has had over 700 hours of post graduate continuing education.

Dr. DeMello has lectured on the topic of one visit porcelain crowns and tutors new CEREC CAD/Cam users.

He has been married to Paula since 1982 and has been an involved parent to Laura, Matt, and Joel, his three children who have achieved state wide recognition in sports, music, and theater.  Over the years he coached little league baseball, basketball, and soccer.

He was a volunteer in Operation Clean Government and was elected to the Lincoln Town Council, the Lincoln Zoning Board, two Town Charter Review Commissions, and Chairman of the Lincoln Democratic District Committee for three terms.

He enjoyed skiing and windsurfing for many years.  He enjoys sailing, fishing, motor boating, has ridden motorcycles since he was 18, and played the guitar since he was 12.