Our Team

Dr. Mercedes Leoncio was born and raised in the Bay Area.  She attended college at the University of the Pacific Stockton campus in the advanced pre-dental program.  During her time at Pacific, Dr. Leoncio served as President of the tri-Beta, the National Biological Honors Society and earned her Bachelor of Sciences degree, graduating Cum Laude.  She then went on to the University of the Pacific School of Dentistry where she earned her Doctorate of Dental Surgery. During her time at the Dental School, she served as President of the Delta Sigma Delta Fraternity.  She is currently a member of the American Dental Association, California Dental Association, Southern Alameda County Dental Society, California Center for Advanced Dental Studies and the American Academy of Clear Aligners.  Dr. Leoncio loves working on children and has a passion for her Invisalign cases as a Gold-Plus tier Invisalign provider. She enjoys serving at the the Union City Pacific Clinic in their annual “Give Kids a Smile” event.   In her free time, Dr. Leoncio enjoys playing volleyball, tennis, cooking, spending quality time with her family and going to sporting events (Go Niners, Go Dubs, Go A’s!!).

Dr. Onea received his Doctor of Dental Surgery degree from the University of Pacific San Francisco, and completed a three year post-doctoral periodontal program at the University of Oklahoma Health Sciences Center, where he received a Master of Sciences degree in Periodontics. His educational background also includes pre-doctoral studies completed at California State University, Hayward, where he received a Bachelor of Science degree in General Biology, and prior to that a Biology teaching degree from the College of Baia Mare, Romania.

He is a member of the Alpha Epsylon Lambda Honor Society , American Academy of Periodontology, California Periodontal Society, American Dental Association, California Dental Association and Sacramento Dental Society.

Dr. Onea’s knowledge and experience in the field of Periodontics were tested and endorsed by the American Board of Periodontology of which he is a diplomate – a significant accomplishment for a periodontist. He has Advanced Cardiac Life Support certification, he is a provider of Continuing Education courses for dentists, and a California state inspector for IV sedation certifications.

His active lifestyle and hobbies include dentistry and its gadgets, nature photography, skiing, kayaking, motorcycles and traveling .

Dr. Amun Rattan is a lifelong resident of the Bay Area who studied at University of the Pacific for his advanced general dentistry residency, Doctorate of Dental Surgery, and Bachelor’s degree in Biology. He is a current member of the American Dental Association, California Dental Association and the Southern Alameda County Dental Society. Dr. Rattan is known for patiently educating his patients with anything from tips to care for their oral health at home to detailed discussions of the risks and benefits of same-day treatment options, and he says that his favorite thing about dentistry is building long term relationships with his patients based on compassion and mutual trust. Outside of the office, Dr. Rattan can often be found cooking or baking, making music, watching movies and relaxing with family. 

Dr. Nguyen is a Bay Area native who grew up in Cupertino and graduated cum laude from UC San Diego with a bachelor’s degree in Biochemistry and Cell Biology. Loving her time and the weather in Southern California, she went on to receive her DDS from UCLA School of Dentistry. Dr. Nguyen then embarked on an adventure and moved to New York City to complete a rigorous General Practice Residency at Lincoln Hospital in South Bronx where she gained further exposure to all aspects of dentistry and fell in love with the Big Apple. Dr. Nguyen’s favorite part of being a dentist is getting to meet new patients and developing the patient dentist relationship. She is a member of the Santa Clara Dental Society, California Dental Association and American Dental Association. In her free time Dr. Nguyen loves being active, hiking, trying out new restaurants and spending time with family and friends. Dr. Nguyen has a sweet tooth and loves baking and drinking boba. 

Dr. Rojean Gaeni is a first-generation immigrant from Iran, who was raised in the Bay Area. She embarked on her academic journey at the University of California, Davis, where she earned her B.S. degree in Neurobiology, Physiology, and Behavior. Driven by her passion, she then pursued her lifelong dream and attained a Doctor of Dental Surgery (D.D.S.) degree from the University of the Pacific, San Francisco.

With a deep-rooted commitment to dentistry, Dr. Gaeni’s primary focus is ensuring her patients’ needs are met with the utmost priority and quality. She takes great pleasure in working with individuals of all age groups, guiding them towards achieving optimal dental health and confident smiles.

Beyond her professional life, Dr. G cherishes moments spent with her loved ones and friends. She finds fulfillment in exploring new destinations through travel, experimenting with diverse cuisines in her kitchen, and immersing herself in multicultural events.

Alondra obtained her Dental Hygiene degree from Diablo Valley College. She is extremely passionate about her career as a dental hygienist and enjoys providing exceptional patient care. Alondra’s priority is to provide individualized preventive and therapeutic treatment while upholding excellent standards of care.  She loves to educate and empower her patients to keep up or start a good oral home care routine in order to maintain or achieve good oral health. Alondra ensures every patient in her care is comfortable with her soft touch and empathy. Additionally, she is fluent in English and Spanish.  

Wendy has been practicing in the dental field since 2002. She became a Registered Dental Assistant in 2006 and decided to get her bachelor’s degree in 2011. She has always wanted to become a Registered Dental Hygienist and graduated in a dental hygiene program in 2017. Wendy has a passion for educating each patient on oral hygiene so they achieve a healthy smile.

Rowena has been working as a Financial Coordinator in medical/dental offices for more than 14 years and she loves her job. She was Medical Receptionist for more than 14 yrs, a medical biller for 12 yrs and a Dental biller (NUVO Dental) since 2014. Her motto: Smile & the world smiles with you =)

My name is Rosswell Liongson and I was born in the Philippines and I moved to the Bay Area back in 2003. I hold a Bachelor’s Degree in Physical Therapy from the Philippines. I’m a Certified Sterile Processing Technician and a Registered Dental Assistant in California. I joined the Nuvo Dental team in 2019. I love being part of “giving our patients that beautiful smile that they deserve” and I love interacting with our patients and working with the staff here each day because everyone is wonderful, patient, kind and helpful.

Outside of work, I enjoy being active in my church as I am a 4th Degree Knights of Columbus officer and a Color Guard member. I like to watch movies, go on bike rides and being with friends and family.  My favorite sport is  Basketball  (Go Dubs!!)