Meet The Doctors


Dr. Tane Rontal is a general dentist practicing family dentistry since 2005. Dr. Rontal started working in the dental field 24 years ago sterilizing instruments and cleaning the office. She soon worked her way up to become a Registered Dental Assistant. Inspired by patients and mentored by leaders in dentistry, she obtained her Bachelor’s Degree in biology at California State University at Hayward. She then was accepted to the Post Baccalaureate Dental Program at UCSF. Dr Rontal received her DDS (Doctor of Dental Surgery) Degree from University of the Pacific, Arthur A Dugoni School of Dentistry in San Francisco.

Dr. Rontal continued her education with advanced training in dental implants, bone grafting and sinus lifts. She has advanced training in Cone Beam 3-D diagnostics for effective dental implant rehabilitation. Dr Rontal has also advanced her education with Progressive Orthodontic education courses. She enjoys learning and sharing treatment options with colleague dentists from all over the United States. She is currently a member of Contra Costa Dental Society, California Dental Association, American Dental Association, Academy of Osseo Integration and Partnership Study Club – community dentists dedicated to advancing their skills and knowledge in implant dentistry.

 Dr. Rontal has shared her skill globally. She has been to Kenya twice to provide free dentistry to the Masai Tribe. While there, she also visited schools, handing out pencils and educating the children on proper hygiene. Besides dentistry, traveling is her passion. She hopes to see and explore the world as much as possible. Dr. Rontal married her husband and his daughters in 2014. She is in the process of writing a book and hopes to travel abroad for future dental outreach projects. Dr Rontal resides in Shadow Lakes and enjoys being a community mentor.

Dr. Martine Joseph Nau, D.M.D

 Dr. Joseph, originally from Quebec, Canada, is fluent in both English and French. She brings to Delta Bay Dental Group over 20 years of experience in all disciplines of dentistry including: cosmetic dentistry, dentures, crown and bridges, implant restorations, endodontics, periodontics, oral surgery, family dentistry, and geriatric dentistry. 

Dr. Joseph is skilled in the latest dental technology and takes a personal and caring approach to make each patient visit comfortable and pleasant. In particular, she greatly enjoys working with seniors to meet their often complex dental needs.

Dr. Joseph is married and the mother of two lovely children. She enjoys spending time with the family at the tennis club, water skiing, gardening, and cooking. 



Dr Eva is originally from Germany and is fluent in both German and English. She is a graduate of the University of the Pacific School of Dentistry and is a general dentist who enjoys all phases of dentistry, especially treating children. She brings 10 years of experience to Delta Bay Dental.

She provides quality dentistry and prides herself for her thorough and gentle care of patients of all ages. Her goal is to help people achieve lifelong dental health.

 In her spare time, Dr Eva enjoys reading, music and spending time with her family. She is often found visiting Brentwood’s many parks with her husband Ryan and their two young children, Erik and Klara.