MEET OUR EXPERT TEAM
Our primary goal is to listen to your needs and build a partnership with you so that we can provide the best, most advanced periodontal care possible.
Dr. Mahmoud Hamad
Dr. Na Eun (Sarah) Chung Grimes
Dr. Gary Li
Periodontist
Tuesdays and Thursdays
Fridays by Appt only
Periodontist
Wednesdays
Periodontist
Mondays
Dr. Hamad is a passionate periodontist focused on delivering personalized, comprehensive solutions for your dental and gum health. His journey began at Florida Atlantic University and continued through dental school at Western University of Health Sciences. He then sharpened his expertise with a periodontal residency at Harvard School of Dental Medicine and is certified in LANAP, a minimally invasive laser treatment for gum disease. Fluent in both Arabic and English, Dr. Hamad is able to communicate clearly with a diverse patient population, ensuring every patient feels understood, comfortable, and confident in their care.At Dartmouth Periodontics, Dr. Hamad blends top-tier training with real-world experience to provide care that is both advanced and approachable. He knows that every smile is unique and so is every treatment plan. That is why he takes the time to ensure you fully understand your condition and the best options available.
More than a specialist, Dr. Hamad is a collaborator. He works closely with your general dentist and other providers to design seamless, customized care because your oral health deserves a team approach. Whether you need periodontal maintenance, dental implants, or treatment for gum disease, Dr. Hamad delivers with skill, precision, and heart.
At every step, your comfort and clarity come first. Ready for expert care that puts you at the center? Discover the Dartmouth Periodontics difference with Dr. Hamad today.
Dr. Na Eun (Sarah) Chung Grimes is a periodontist who was raised in Orange County, California, and earned her B.S. in Biology from the University of California, Irvine. She went on to receive her Doctor of Dental Medicine degree from Tufts University School of Dental Medicine in Boston, Massachusetts, where she discovered her passion for periodontology. This led her to complete a three-year residency in periodontics at the University of Southern California. Fluent in Korean and English, Dr. Chung is able to connect with and provide clear, personalized care to a diverse patient population. Prior to relocating to Cape Cod, Dr. Chung served as an Assistant Clinical Professor in the Department of Periodontology at the University of Southern California, while also maintaining a private practice.
Dr. Chung strongly believes that optimal health begins with prevention and is dedicated to helping her patients achieve and maintain excellent oral health. She finds particular fulfillment in restoring smiles through dental implants and grafting procedures, combining science and artistry to deliver healthy, confident results. Committed to staying at the forefront of dentistry, Dr. Chung regularly attends continuing education courses to remain current with the latest advancements and techniques.
Outside of her professional life, Dr. Chung enjoys spending quality time with her husband and son, and loves exploring the natural beauty and communities of Cape Cod.
Dr. Gary Li is a board-certified periodontist in periodontics and dental implant surgery. Originally from Boston, Dr. Li graduated with honors from Boston University School of Dental Medicine. Driven by his passion for the specialty, he went on to complete the Periodontology Program at Tufts School of Dental Medicine, serving as Chief Resident during his time there. He is the recipient of both the prestigious Predoctoral American Academy of Periodontology Award and the American Dental Partners Foundation Scholarship.Fluent in Chinese and English, Dr. Li is able to communicate effectively with a diverse patient population, ensuring each patient feels comfortable and well-informed throughout their care.
Certified in LANAP (laser treatment for periodontal and implant disease), Dr. Li strives to provide personalized and comprehensive dental care for each patient. His friendly and approachable nature makes him not just a skilled periodontist, but also a relatable healthcare provider.
Outside of his professional life, Dr. Li enjoys exploring new restaurants, golfing, and following the Celtics.
Dr. Natalie Yam
Cheryl Sullivan
Michael Araujo
Periodontist
Saturdays by appointment only
Hygienist
Tuesdays and Wednesdays
Hygienist
Mondays, Wednesdays and Thursdays
Dr. Natalie Yam is a board-certified periodontist and LANAP-certified clinician dedicated to helping patients achieve lasting oral health and confident smiles. Her passion for dentistry began early, shaped by hands-on experience long before dental school. After earning her Doctor of Dental Surgery degree from NYU, she completed a rigorous residency in Periodontics at the Harvard School of Dental Medicine, where she trained with some of the top experts in the field.Fluent in Chinese and English, Dr. Yam is able to communicate clearly with a diverse patient population, helping patients feel comfortable, informed, and confident in their care.
Dr. Yam believes in care that goes beyond treatment. She empowers her patients through education, giving them the tools and knowledge to take charge of their oral health. Her approach focuses on lasting results, with an emphasis on personalized guidance and sustainable oral hygiene habits.
She supports patients in building lifelong habits and maintaining control of their oral health—well beyond the dental chair. Whether guiding you through treatment or helping you fine-tune your daily routine, she is with you every step of the way.
Cheryl Sullivan, RDH, brings over four decades of experience in dental hygiene, beginning her career in 1979. She earned her Dental Hygiene degree from Cape Cod Community College and is also a Certified Dental Assistant, having graduated from Diman Vocational School in 1975.Cheryl spent 35 years at Dartmouth Periodontics under Dr. Ralph Pollack and has continued to provide exceptional patient care alongside Dr. Soo Woo Kim, Dr. Guzen Uzel, and most recently, Dr. Hamad. Her extensive experience and long-standing commitment to the practice reflect her dedication to patient care and clinical excellence.
Known for her gentle approach and strong patient relationships, Cheryl is passionate about helping patients maintain their oral health through education and preventive care.
Outside of the office, Cheryl enjoys spending time with her family, including her two children and two granddaughters.
Michael Araujo, RDH, earned his Bachelor’s degree in Biology from UMass Amherst in 2014 and his Bachelor’s degree in Dental Hygiene from Massachusetts College of Pharmacy and Health Sciences in 2017, where he served as class president. With over 10 years of experience in dental hygiene, Michael is committed to providing high-quality, patient-focused care with an emphasis on prevention and education.
Proficient in Portuguese and English, Michael is able to communicate effectively with a diverse patient population, helping patients feel comfortable and confident in their care.He strives to create a supportive environment while helping patients achieve and maintain long-term oral health.
Outside of the office, Michael enjoys staying active and spending time outdoors. He is passionate about sports, especially football and basketball, and enjoys fishing, kayaking, snowboarding, volleyball, and paddleboarding.
Amy
Office Manager
Remote
Amy began her dental career in 2014 as a lead assistant in general practice before transitioning into periodontics in 2016. She later served as a state lead assistant in Colorado for a corporate organization, supporting six providers across more than 30 offices and helping maintain consistency in patient care and clinical systems.In 2018, Amy joined a private periodontal practice, continuing chairside while also supporting corporate operations to improve workflow and enhance the patient experience.
She now works remotely with Dartmouth Periodontics, collaborating closely with providers and the team to support both clinical and operational excellence. Amy has worked alongside Dr. Hamad since 2020, both chairside and in a support role.She also manages an international dental education program in Mexico, coordinating hands-on surgical training for U.S. dentists.
With experience in both front and back office roles, she brings a well-rounded perspective and is a valuable resource to both patients and the team. While primarily behind the scenes, she visits the office throughout the year to work in person.
Teresa
Billing Coordinator and
Continuting Education coordinator
Teresa has been a valued member of our team for over two years, serving as Front Desk Coordinator, Billing Coordinator, and Referral Coordinator. She is known for her kind personality, professionalism, and willingness to help patients and colleagues alike.
Teresa takes pride in creating a welcoming environment while ensuring day-to-day operations run smoothly and efficiently. Fluent in English, Portuguese, and Spanish, Teresa is able to assist and connect with a diverse range of patients and families.
Her dedication to excellent service and clear communication makes her an important part of our office. Outside of work, Teresa enjoys spending time at the beach and listening to country music.
Chelynne
Treatment Coordinator and Insurance Specialist
Chelynne has been in the dental field since 2013 and serves as our Treatment Coordinator and Insurance Specialist. She plays a key role in helping patients navigate their care—from understanding treatment recommendations to coordinating appointments and managing insurance benefits. With a strong knowledge of both clinical treatment and insurance processes, Chelynne works closely with patients to provide clear financial guidance, verify coverage, and help maximize their benefits.
Her goal is to make the entire experience as smooth, transparent, and stress-free as possible. Known for her friendly and approachable nature, Chelynne is dedicated to ensuring every patient feels comfortable, informed, and confident in their care.
Outside of the office, she enjoys going to the theater, attending concerts, and trying new restaurants.
Anna
Surgical Dental Assistant
Anna has been a dedicated dental assistant for over 44 years, bringing extensive clinical experience and a deep commitment to exceptional patient care. Throughout her career, she has built a reputation for her gentle approach, attention to detail, and ability to make patients feel comfortable and at ease during their visits. She takes pride in supporting both patients and providers, ensuring each appointment runs smoothly while maintaining a high standard of care.
Fluent in Portuguese and English, Anna is able to connect with a diverse patient population, helping patients feel understood, supported, and confident throughout their treatment.
Outside of the office, Anna enjoys spending time with family and friends and has a passion for baking.