Meet The Doctors

Lillian R. Liberto, DDS


Dr. Liberto, a local San Diegan is a graduate of the University of California, San Diego, 1985 and of the University of the Pacific School of Dentistry, 1990, now known as the Arthur Dugoni School of Dentistry, in San Francisco.  She regularly devotes her time to advanced training and continuing education pursuing the best of the latest techniques that dentistry has to offer.  Dr. Liberto is a certified Invisalign dentist, which enables her to bring the most advanced form of orthodontics to her patients. 

Professionally, she is an active member of the American Dental Association, the California Dental Association and the San Diego Dental Association, serving on several boards to find ways to connect with the dental community.  She is a lifetime member of Delta Sigma Delta. And serves on San Diego Mesa College's Dental Assisting Advisory Board.  In addition, Dr. Liberto serves as a mentor for SDSU in her field, with the Aztec Mentor Program. Nominated for excellence in ethics in the dental field to the Pierre Fauchard Academy Fellowship.

She has been recognized by her patients  in the San Diego Union Tribune Readers Poll of 2015 as "San Diego's Best." And she has recently been nominated and recognized by her peers and colleagues as one of San Diego Magazine's Top Dentist 2017, 2018, 2019 & 2020.

Dr. Liberto is actively involved in her children's extracurricular activities.  She has been involved with the Tierrasanta community since 2002 and was a member of the Tierrasanta Women's Club. 

Her interests include her church and numerous activities including exercising, health, skiing, hiking and spending time with her husband and her family.  She and her husband Tom, are the proud parents of four children Victoria, Sabrina, Nicholas, Amanda and their new son in law Daniel now completing their family.

Douglas Cassat, DDS


Dr. Cassat is a 1971 graduate of United States International University, Cal Western Campus and 1975 graduate of Georgetown University School of Dentistry.  He moved to Tierrasanta in 1976 and opened his dental practice in 1978. "I can't believe it has been 34 years, it seems like yesterday!"

Besides dentistry, Dr. Cassat has been involved with the Tierrasanta community in many ways, serving on the Tierrasanta Community Council and as its President from 1981-1983.  He was also active in the Tierrasanta Kiwanis Club in those early years. He served on the Copley Family YMCA Board of Governors from 1985-1999.

Professionally, Dr. Cassat has always been very active in the San Diego County Dental Society, serving as its President in 1991-1992, Trustee to the Caifornia Dental Association, Board of Directors of the Dentists Insurance Company, on the Council on Members Insurance and Retirement Programs of the American Dental Association, and as a Director on the board of Delta Dental of California.

Dr. Cassat has been recognized by his peers with Honorary Fellowships in the Pierre Fauchard Academy, the American College of Dentists and International College of Dentists.

On the personal side, Dr. Cassat and his wife Jae live in Scripps Ranch and have two daughters and a dog named Spot!  In his spare time he is trying to learn to play a respectable game of golf.