The brief descriptions below are designed to familiarize you with our staff's training, professional credentials and work experience.


John Powers, DMD

John Powers, DMD

Dentist in Greenbelt, MD

John Powers, DMD, PC

Dr. Powers has been practicing dentistry for more than 30 years. After graduating from the University of Massachusetts at Amherst, he attended the University Of Pennsylvania School Of Dental Medicine, receiving his dental degree in 1980. After a general practice dental residency, Dr. Powers began practicing in Greenbelt, Maryland in 1981.

He was Chairman of the Dental Department of a Washington, D.C. Area Trauma Hospital for more than a decade. There he was involved in training dental residents that graduated from dental schools across the United States. Currently he is a member of the Deans Faculty at the University of Maryland School of Dentistry.

Dr. Powers is an active member of the American Academy of Oral and Systemic Health, Oral Cancer FoundationAcademy of Laser Dentistry,  American Academy of Cosmetic Dentistry, American Academy of Dental Sleep MedicineAmerican Dental Association, Maryland State Dental Society, Southern Maryland Dental Society, Dental Organization for Conscious Sedation and BiCounty dental study club. He was also voted as a "Best Dentist" by Washingtonian Magazine.

Patients love Dr. Powers' empathetic and compassionate dental care. In addition, they appreciate his desire to expand and advance his dental expertise. He frequently attends courses on Oral-Systemic Health, Laser Dentistry, Smile Design, Invisalign, Ultimate Occlusion, Sedation Dentistry Oral Cancer detection and prevention. Thus, he's able to empower his patients with an array of treatment options.

Dr. Powers and his wife truly enjoy raising their two children who are both currently in dental school. He has many varied hobbies, including tennis, bicycling, digital photography, computers and a good book. He has also received his third degree black belt in Taekwondo.



Terrie Deters

Terrie Deters

Terrie is our business office administrator. Her dental experience spans four decades as a certified dental assistant, consultant and business office manager. She enjoys working with patients to help them achieve their dental journey and continuing her education keeping dentistry her career passion.

Outside the dental office, Terrie enjoys gardening, pool time, a sunny beach and sleep overs with her grandchildren. She has been married to her best friend, Dan for 43+ years. Together they have enjoyed the blessings of their two grown children, their spouses, six grandchildren and continued fun with their elderly parents. Terrie also enjoys her large Italian-German family and can always be found preparing for a family event. Quiet time seldom exists for this happy grandmother as her grandchildren light up her world.


Sonai (Sunny) RoySonai (Sunny) Roy

Sonai is the newest addition to our practice with over 17 years of experience in customer service and 2+ years in the dental healthcare field. As scheduling coordinator/ social media administrator in our practice she takes great pride and joy in getting to know our patients. The care and well being of our patients is her highest priority.  She is extremely happy to take part in giving them a great dental experience.

Sonai is the youngest of 6 siblings! Coming from a military family she has no problems making friends wherever she goes. Sonai currently resides in DC. She loves to play “tourist” in DC and find events to do with her family. She prides herself on finding great deals and being thrifty. She is a lover of life! Her alias “Sunny “ completely embodies her bright personality.

Angelie Newgen, RDH


Angelie Arroyave, RDH

Angelie is our newest dental hygienist. She brings 13 years of experience in the dental field and one of her instructors in hygiene school at Fortis College was her predecessor, Sandra, so we know she's well trained! She brings the latest advanced techniques to her patients and really enjoys what she does to help them become as healthy as possible.

Angelie was born and raised in Northern Virginia and is the youngest of four sisters.  She enjoys quality time with her family.



Janet Freitag, RDH

Janet brings our dental team a vast amount of clinical experience spanning over 40 years, starting with assisting her father's dental practice. She works primarily as a dental hygienist earning her degree from Allegany College but you might also see her assisting Dr. Powers or working the front desk.

She as been a Dental Hygiene "Lead" for Mission of Mercy (a free dental clinic held at the University of Maryland) for the last 8 years.

Janet keeps her fingers limber with quilting (Even making a quilt for Mission of Mercy that was raffled off). In addition, come springtime, you can find her digging in her flower and vegetable garden.

She and her husband Bernie, have one daughter, Holly and a brand new son in law, Steven. They enjoy family time together camping and attending music festivals. 


 Debbie Swingle, RDA

Debbie Swingle, RDA

Debbie, a registered dental assistant, has been working with Dr Powers for 13 years of her 23 year dental career. She has a great wealth of dental information to draw on. Debbie is a true care giver, in every sense of the word. Being very patient oriented, she ensures that all of our patients are comfortable and given the best care available. She takes great pride in what she does.

Debbie is a native Marylander. She is married with four grown children. Debbie enjoys camping, gardening, riding motorcycles and caring for others. Above all, she loves her eight grandchildren, including a set of twins.


 Barbara Sherry, RDH

Barbara Sherry, RDH

Barbara has been a practicing dental hygienist for over 30 years. She first entered the field of dentistry as a certified dental assistant in 1978. After working for a few years and with a desire to further her education, she headed to Allegany Community College in Cumberland, Maryland, where she earned her dental hygiene degree in 1982.

Barbara and Dr. Powers met 30  years ago and worked together for several years before Dr. Powers opened his own practice. In 1992, Barbara reestablished her working relationship with Dr. Powers and joined him in his Greenbelt office. Currently, Barbara works days when needed to provide support for others in the practice.

Barbara has been married to her husband for 28 years. They have three wonderful children.


Contact Us

John Powers DMD PC

(301) 441-8686

 [email protected]

8955 Edmonston Road Greenbelt, MD 20770-1023