Dr. Pat Cassidy


Dr. Pat Cassidy, a native of Vancouver, British Columbia, is committed to providing high quality dentistry with a very gentle touch to every person that entrusts him with their care. He received his dental degree from the University of British Columbia in 1976 placing first in his graduating class, and completed his Masters in Public Health at the University of North Carolina at Chapel Hill in 1980. (Go Heels!)

Dr. Cassidy has practiced in Durham 19 years. He emphasizes preventive care as well as providing a wide range of restorative options to patients including Waterlase laser dentistry (often requiring less anesthetic), tooth colored fillings, veneers, crowns and bridges, implant restoration, partial dentures, root canal treatment, and Invisalign (“invisible” braces). Dr. Cassidy is happily married to his wife Donna, a native of Durham, and is the proud father of three children, Crystal, Lance, and Darren.

Dr. Cassidy and Donna have contributed further to the practice of dentistry by creating and patenting methodology which serves the dental profession with a unique comparison-shopping marketplace at www.net32.com.

Dr. Lopez

Dr. Angel Lopez


Dr. Angel Lopez received his dental and medical degree from the University of Puerto Rico in 1988 and has dedicated his professional career to providing his patients with exceptional care. He has been a faculty member at the University of Puerto Rico, the University of Massachusetts and Harvard University. He is a member of the American Dental Association, the North Carolina Dental Society and the Hispanic Dental Association.

Dr. Lopez is fully bilingual in English and Spanish and is continually participating in advanced training and continuing education. Dr. Lopez concentrates his practice in oral rehabilitation with strong cosmetic and endodontic components. He is married and is the proud father of 3 teenagers. Dr. Lopez enjoys coaching youth baseball and basketball.


Dr. Brian Cahill


A native of Virginia, Dr. Brian Cahill earned his Bachelor of Science from Arizona State University in 1994, and his Doctor of Dental Surgery from The Medical College of Virginia in 1999. Following graduation, Dr. Cahill opened and operated a highly successful family practice in Mesa, Arizona.

Dr. Cahill and his family relocated to the Research Triangle in 2009, where he joined forces with the superlative team at Research Triangle Dental. Dr. Cahill has participated in hundreds of hours of post-graduate continuing education, with special emphasis on cosmetic and implant dentistry. Dr. Cahill has extensive training in all aspects of General Dentistry including routine restorative care, crowns, bridges, root canals, veneers, implant restorations, and Invisalign. Dr. Cahill is married to his lovely wife Laurie, and has 3 wonderful children- Dustin, Ashley, and Tyler.


Dr. Mark Walker


Dr. Mark Walker was born and raised in Western New York. After receiving a Bachelor of Arts degree in Biology from the University of New York at Buffalo, he graduated cum laude with a Doctorate of Dental Surgery (D.D.S.) from the University of New York at Buffalo School of Dental Medicine in 1994. Dr. Walker practiced in New York and Colorado until he decided to settle in Albuquerque, New Mexico in 2001 and establish a practice.

After nearly 15 years in the desert, Dr. Walker decided to move back to the east coast, choosing North Carolina for his new home. Dr. Walker and his wife Karen, a teacher, enjoy spending time with their family and are very proud of both their daughter who is in middle school and their son, who is in the U.S. Army. During his free time, Dr. Walker enjoys running/fitness, traveling, and landscaping.

Throughout his career, Dr. Walker has continued his education with an emphasis in comprehensive restorative dentistry, cosmetic dentistry, and TMD/chronic facial pain therapy. In the last ten years he has completed well over 1000 hours of continuing education to be able to bring the best and most current care to the families he cares for. Dr. Walker is a provider of Invisalign® and has extensive training and experience in Comprehensive Restorative Dentistry, Dental Sleep Medicine and Therapeutic Chronic Pain/TMJ Management. Dr. Walker’s dedication to continuing his education allows him to customize the care of each individual. Each of Dr. Walker’s patients will receive his full attention and expertise whether for extensive care or simple routine care. He demonstrates uncompromising ethics and provides straightforward solutions to assist you in developing your care plan. He brings a thorough, caring, and honest style to dentistry with a kind approach. His consistent desire to keep abreast of advancements in dentistry motivates his continued dedication to the profession, and to the quality of care for you and your family.