About Your Dentist

Brendan J. Hallissey, DMD, AFAAID

Dr. Hallissey is originally from Machias, Maine. He went to high school in Bangor, Maine, and attended Bowdoin College in Brunswick, Maine. After receiving his DMDfrom the University of Connecticut in 2006, he began working as a dentist at the Penobscot Community Health Center in Bangor, Maine.

Dr. Hallissey spent five years working with all aspects of dentistry, including the restoration and placement of implants. He 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, as well as taken the MAXI Course through the American Academy of Implant Dentistry. 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.

In August of 2011, Dr. Hallissey moved to Portsmouth, NH, 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

"Any barbarian can make coffee, but it takes a civilized person to make an espresso." – French Proverb

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 ballet since the age of 2, Dr. Lexi pursued all forms of dance throughout high school, as well as her college career at Cornell University in Ithaca, New York. After completing her Honors degree, focusing on World War II history and historiography, French studies, and Scottish history, Dr. Lexi went on to pursue her Doctorate of Dental Medicine at Boston University.

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. Dr. Lexi dedicates her practice of dentistry to the prevention of oral cancer, minimally-invasive dentistry, and championing her patients' comprehensive healthcare. She's focused on continuing education and remaining up-to-date with the latest techniques and technologies available to assist her patients in obtaining optimal oral health.

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

My Mission

"To provide comprehensive, state of the art, family dental care in a clean, safe environment. My goal is to provide patient-centered care of the highest quality in a stress-free, comfortable 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."


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

University of Connecticut - Storrs, CTMasters in Psychology and Neurobiology

University of Connecticut - Storrs, CTBachelor of Science in Biology

Professional Memberships

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