About Your Dentist

Brendan J. Hallissey, DMD

"Let us always meet each other with smiles, for a smile is the beginning of love." - Mother Teresa

My Mission

“My goal is to provide individualized, patient-centered care of the highest quality in a stress-free, comfortable environment.”


Doctorate of Dental Medicine
University of Connecticut School of Dental Medicine – Farmington, CT

Bachelor of Arts in Biochemistry
Bowdoin College - Brunswick, Maine

Dedicated to Professional Excellence

In order to continually improve and better serve his patients, Dr. Hallissey is dedicated to continuing education and keeping up to date with the latest techniques and technologies available. After receiving his DMD from the University of Connecticut in 2006, Dr. Hallissey worked with all aspects of dentistry, including the restoration and placement of implants at the Penobscot Community Health Center in Bangor, Maine. He also taught implant placement, bone and soft tissue grafting, and surgical extractions at the Penobscot Community Health Center General Practice Residency, where he served as the Director of Clinical Services. He has also held adjunct faculty positions with A.T. Stills in Arizona, Boston University, University of Iowa, University of North Carolina, and Tufts University. He has also completed the MAXI Course through the American Academy of Implant Dentistry. 

Life & Hobbies

Dr. Hallissey is originally from Machias, Maine. In August of 2011, he moved to Portsmouth, New Hampshire to enter private practice. He is an avid outdoorsman and enjoys gourmet cooking with his wife, Alexis. In the winter, Dr. Hallissey can be found indoors playing volleyball and hockey.

Alexis Marthajane Fraser Hallissey, DMD

"The distance does not matter; it is only the first step that is difficult." – Marie de Vichy-Chamrond, Marquise du Deffand

My Mission

“My patients can depend on me to act as their advocate for comprehensive, minimally invasive dentistry and the prevention of oral cancer.”


Doctorate of Dental Medicine
Henry M. Goldman School of Dental Medicine
Boston University – Boston, MA

Bachelor of Arts
Honors degree, focusing on World War II history and historiography, French studies, and Scottish history
Cornell University - Ithaca, NY

Continuing Education

Dr. Hallissey is committed to continuing education and advanced training in the latest techniques and technologies available to assist her patients in obtaining optimal oral health. After successfully completing her dental residency from 2010 to 2011 at St. Francis Hospital in Hartford, Connecticut, Dr. Lexi moved to the Seacoast, where she practiced dentistry for 5 years in Epping, New Hampshire. In 2013, Dr. Lexi obtained her certification and proficiency in laser dentistry with the Academy of Laser Dentistry, of which she is currently a member. She began working in Kittery in January of 2015. 

Life & Hobbies

Dr. Alexis "Lexi" Marthajane Fraser Hallissey was born and raised in Delaware. She attended Wilmington Friends School from Kindergarten through twelfth grade, spending her summers in the beach town of Lewes, Delaware. Having trained in ballet since the age of 2, Dr. Lexi pursued all forms of dance throughout high school, as well as her college career.

When she isn't helping her patients, Alexis enjoys spending quality time with her husband, son, and toy fox terrier. At home, she loves gardening, cooking, baking, interior design, outdoor projects, and herbal therapy. When time permits, she practices yoga, swimming, spinning, and outdoor exercise programs. 

Thomas Guerrette, DMD

“Serving the community, one smile at a time.”

My Mission

"To provide state of the art, family dental care in a clean, safe environment. I make sure to take the time to discuss all the relevant treatment options with each patient in order to accommodate their specific needs, expectations, and budgetary considerations. I strive to make sure my patients achieve optimal oral health through education and comprehensive dental care."


Doctor of Medicine in Dentistry 
University of New England College of Dental Medicine - Portland, ME

Master of Science in Psychology and Neurobiology 
University of Connecticut - Storrs, CT

Bachelor of Science in Biology 
University of Connecticut - Storrs, CT

Professional Memberships

Dr. Guerrette is a member of the American Dental Association, Academy of General Dentistry, and the New Hampshire Dental Society.

Life & Hobbies

In his free time, Dr. Guerrette enjoys hiking, mountain biking, and snowboarding. He currently resides in Wells, Maine with his wife and two daughters.