Amy Vanderbilt-Fessa, RDH

Registered Dental Hygienist 

Our Staff of hygienists are very experienced. Our hygienists have been in the dental field for 10 years or more as dental assistants and hygienists. They have each worked in our office for over 10 years. They earned their degrees from San Joaquin Valley College and Chabot College. Our staff keeps up with the latest techniques and innovation, especially around periodontal disease, through regular continuing education. They are very personable and work to understand the needs of each patient.

Meet Dr. Sommer

Rosa Hernandez-Manzano, RDA

Registered Dental Assistant

Claudia Garcia-Garcia, RDA

Registered Dental Assistant

Jessica Cortez, RDH

Registered Dental Hygienist

Dr. Sommer and her husband are proud to have raised their daughters in Livermore and to have been part of the Livermore community for over 30 years. They are supporters of local performing arts groups and are founding members of the Bankhead Theatre. When she is not in the office, Dr. Sommer enjoys walking and biking on trails around the Tri-Valley, singing in her church choir, and swimming.  She also enjoys travelling in the U.S. and abroad to visit friends and family near and far. Take a look around the office for photos of waterfalls from some of Dr. Sommer’s favorite destinations!

Dr. Sommer is a member of the ADA, CDA, Southern Alameda County Dental Society, and the American Dental Association Advisory Circle.

McKinley Sequeira

Administrative Assistant


Dr. Sonja Sommer grew up in Santa Rosa, California as a first-generation Danish-American. She knew she wanted to go into health care from a young age from watching her mother have a successful career in nursing. She attended the University of California, Davis and earned a Bachelor of Science degree in Animal Physiology in 1989.  She then went on to receive her Doctorate of Dental Surgery degree from the UCLA Dental School in 1993.

Dr. Sommer came to Livermore after dental school to join her husband who had started his career at the Lawrence Livermore National Laboratory. She practiced in a few offices in Livermore and Pleasanton before starting work with this practice in 2000. She has remained with this practice ever since and became the owner in 2006. Dentistry continues to provide Dr. Sommer with the opportunity to apply the benefits of scientific knowledge to help others have a healthy smile. Her goal for the practice and motivation for dentistry have always been to build and maintain collaborative and trusting relationships with patients in order to support their dental health needs.

Guadalupe "Lupita" Valencia

Dental Assistant

Amy "Lou" Ingram, RDH

Registered Dental Hygienist

Call now: (925) 449-8788

Meet Our Staff

Carly Pschier, RDA

Registered Dental Assistant, Office Manager

Wendy B. Duong, DMD

Doctor of Medicine in Dentistry

For All The Smiles In Your Family