Norman J. Hammer

M.S., D.D.S.
Prosthodontics, Implant Prosthodontics

As a partner at the office, Dr. Hammer has maintained a clinical practice at The Dental Group at Post Office Square since 1990. Dr. Hammer received his dental degree from New York University in 1980. He completed a General Practice Residency followed by a two-year Prosthodontic Residency at the Veterans Administration Medical Center in Buffalo, NY.

His first university academic appointment, in 1982, was at the University of Buffalo School of Dental Medicine and in 1983 he moved to Boston to continue his teaching career with an academic appointment at Tufts University School of Dental Medicine. Presently, Dr. Hammer has a faculty appointment at Harvard University, School of Dental Medicine where he participates in the Advanced Graduate Education Program in Prosthodontics.

Dr. Hammer is a member of the American Dental Association and the Massachusetts Dental Society. In addition, he is a member of the American College of Prosthodontists and a Fellow of the Greater New York Academy of Prosthodontics. Dr. Hammer has an extensive history in academic dentistry and has also lectured extensively in the United States and abroad.

Jack B. Share

DDS, General Dentistry and Esthetics

A native of rural Central New York, Dr. Share earned his Bachelor of Arts undergraduate degree in Biology with honors from Syracuse University in 1970. Receiving his Doctorate of Dental Surgery at the State University of New York at Buffalo School of Dental Medicine in 1974, he graduated with high honors and was duly elected to the prestigious Omicron Kappa Upsilon National Honor Society for his "academic achievements, scholarship and character in dentistry."

After graduation, Dr. Share completed a General Dental Practice Residency and General Anesthesia Internship at the Upstate Medical University in Syracuse to further advance his training in prosthetics and patient care.

Relocating to Boston, Dr. Share accepted a five-year, full-time academic appointment to the faculty of the Tufts University School of Dental Medicine as an Assistant Professor in the Department of Restorative Dentistry. In 1983, the doctor established a private practice in Boston's Financial District and, after 37 years, merged his practice with The Dental Group at Post Office Square in 2021.

Throughout his career, Dr. Share has remained committed to excellence and has strived to provide patients with the highest quality of dental care. He has a deep respect for patients, and along with his amiable and nurturing nature and attention to every detail, is one of the most reputable and well-respected dentists in the greater Boston Area. He is a member of the American Dental Association and the Massachusetts Dental Society, in addition to the Geological Society of America, the Society of Vertebrate Paleontologists and the New York Paleontological Society. Dr. Share has been happily married for over 44 years and has two adult children.

Nancy S. Arbree

DDS, FACP, MS

Dr. Arbree graduated from Georgetown University School of Dentistry and completed a General Practice Residency at the Veterans Administration in Gainesville, FL. She earned certificates in both Prosthodontics and Maxillofacial Prosthetics from Memorial Sloan-Kettering Cancer Center in New York City. Dr. Arbree received a Masters of Dental Science in Research from Tufts University School of Dental Medicine; her clinical research study was on the effect of implant-retained prostheses on geriatric nutrition.

Dr. Arbree is a Prosthodontist, a Diplomate of the American Board of Prosthodontics and a Fellow in the American College of Prosthodontists (FACP), where she served as the first female national President. She is also a member of the American Dental Association and the Greater New York Academy of Prosthodontics, where she also served as its first female President. At Tufts University School of Dental Medicine, Dr. Arbree served as Division Head of Clinical Complete Dentures Prosthodontics and created the first Implant Dentistry Course. Her presentations and publications are in the disciplines of complete dentures, implants and curriculum. Dr. Arbree was the Academic Dean at Tufts from 1996 to 2012. She was granted Professor Emeritus and Academic Dean Emeritus.

In 2012, Dr. Arbree was awarded the first Lifetime Achievement Award by the Georgetown University School of Dentistry Alumni. In 2014 and 2015, Dr. Arbree was awarded the Distinguished Service Award and the Dan Gordon Award, respectively, from the American College of Prosthodontists.

Dr. Arbree has been with the Dental Group at Post Office Square since 1999, where she limits her practice to Prosthodontics. She and her team make a special effort to make patients comfortable, while achieving the best care they can receive, both conservative and advanced.

Dr. Arbree lives in the Back Bay of Boston, where she enjoys spending time with family/friends/ her two Tonkinese cats, playing pickleball, walking, hiking, gardening, cooking, needlework, bridge, reading, theater, museums, touring historic homes and traveling.

Roxanne Sadaghiani

Prosthodontist

Dr. Roxane Sadaghiani is a graduate of Boston University, Henry M. Goldman School of Dental Medicine, where she earned both her DMD, and her Certificate of Advanced Graduate Studies in Prosthodontics. Prior to attending Boston University, Dr. Sadaghiani graduated from the Azad Tehran School of Dentistry in Tehran, Iran. Dr. Sadaghiani limits her clinical practice to the field of Prosthodontics which focuses on providing esthetics and function including Full mouth rehabilitations, implant dentistry, veneers, crowns, bridges and dentures. By taking an individualistic approach that focuses on your dental and oral health needs, she will help you achieve a lasting and beautiful smile.

Dr. Sadaghiani believes continuing her education is mandatory and its critical for her patients to stay updated with the most recent proven advancements in dentistry. She is a member of the American college of Prosthodontics, Massachusetts Dental Society and Spears. While not at work Dr. Sadaghiani likes to listen to music, ballroom dancing, read books, and watch movies. Dr. Sadaghiani speaks Farsi and Azari.

John N. Govostes

DMD, Periodontics and Implantology

Dr. Govostes received his Bachelors of Science degree from the University of New Hampshire and then went to attend Tufts University School of Dental Medicine where he received his dental degree (DMD) and then later his specialty training in Periodontology. Dr. Govostes is a Board Certified Periodontist.

Dr. Govostes limits his clinical practice to the field of Periodontics which focuses on patient education as well as the preservation of teeth through various non-surgical and surgical therapy modalities in the treatment of gum diseases (periodontitis), as well as implant dentistry and the treatment of other oral pathologic conditions associated with the mouth. The various services offered but not limited to, are the: reduction of gingival pocketing, cosmetic correction of recession and reconstruction with various gum grafting techniques, removal of hopeless teeth, replacement of missing or hopeless teeth with dental implants, as well the augmentation of bone which is often times needed for future dental implant placement.

Dr. Govostes is a member of the American Academy of Periodontology, the Massachusetts Society of Periodontics, the Massachusetts Dental society, as well as a member of Delta Sigma Delta organization which is an International Dental Fraternity. Dr. Govostes has served the public by working in community dental clinics in Colorado as well as volunteering for Dental missions to Quito, Ecuador where he treated the underprivileged community. He also serves as a guest lecturer at the Yankee Dental Convention in Boston MA. Dr. Govostes concerns himself with his patient’s comfort, relaxation, and education as well as the quality of care he provides.

Shaima Tabari

D.D.S, Orthodontics and Invisalign

Dr. Shaima Tabari is an American Board of Orthodontics certified orthodontist who is part of The Dental Group at Post Office Square team. She is a dual trained orthodontist with experience working in the US and the UK. She completed her 4-year doctorate program in orthodontics from the Harvard School of Dental Medicine with her thesis focusing on Obstructive Sleep Apnea. Patients visit her for reasons such as Invisalign®, braces and follow-ups on a range of other orthodontic treatment procedures. Dr. Tabari strives to provide patients with a holistic individualized treatment plan which best complements and enhances their quality of life.

In addition to her excellent educational pedigree, she is an avid skier licensed in avalanche search and rescue operations. She also enjoys learning new languages and can so far speak English, French, Farsi, Arabic, Spanish and Icelandic.

Aikaterini Papathanasiou

DMD, DDS, MBA, Esthetic Dentistry

Dr. Papathanasiou earned her Doctor of Dental Medicine degree from Tufts University School of Dental Medicine and is the Director of Advanced Graduate Esthetics and Operative Dentistry in the Department of Prosthodontics. After graduating from the University of Athens Dental School in 1995, Dr. Papathanasiou accepted a full-time faculty position at Tufts in the Department of Prosthodontics and Operative Dentistry where she has been teaching and conducting research.

Shortly after completing her undergraduate dental studies, Dr. Papathanasiou received a Postgraduate Certificate in Operative Dentistry, Endodontics and Cariology from Aarhus University, Royal Dental College, Denmark, and later received additional postgraduate training at Tufts University School of Dental Medicine, where she earned a Postgraduate Certificate of Advanced Education in Esthetics Dentistry.

Dr. Papathanasiou is an internationally recognized lecturer and has numerous publications in peer-reviewed dental journals. She was the Editor-in-Chief of the Greek dental journal Esthetic Dentistry and Implantology and is on the editorial team of Reality Esthetics and the editorial review board of Journal of Cosmetic Dentistry.

Dr. Papathanasiou has two children and when not working, she enjoys spending time with her family and friends, traveling and engaging in numerous sports.

Yasmine Basseghi

DMD, CAGS, Endodontist

Dr. Yasmine Basseghi graduated from Birmingham-South College where she earned a Bachelor of Science degree in biology and psychology. She moved on to Boston University Goldman School of Dental Medicine where she received a Doctor of Dental Medicine degree. From there, she completed her residency in the advanced specialty program in general dentistry at Boston Universit, then specialized in endodontics.

Dr. Basseghi specializes in endodontics, which involves dental pulp and tissues surrounding the root of the tooth. Not only does she specialize in this field at The Dental Group at Post Office Square in Boston, MA, but she is a clinical instructor in the field at both Boston University School of Dental Medicine and Tufts School of Dental Medicine in the department of endodontics. Dr. Basseghi is proud to belong to the American Association of Endodontists.

Ryan Canesi

DMD, General Dentist

While studying biology at Boston College, Dr. Ryan Canesi found his love for dentistry while he volunteered at the dental clinic at the East Boston Community Health Center. Once he graduated, he moved on to earn his Doctor of Dental Medicine degree from Tufts University School of Dental Medicine. Dr. Canesi strives to provide a quality and caring dental experience for his patients using the latest technologies. Dr. Canesi is passionate about continuing to educate himself in the field of dentistry and values staying up to date on the latest techniques, trends, and treatments. He is proud to be a member of the American Dental Association and the Massachusetts Dental Society.

Dr. Ryan Canesi specializes in general dentistry. He is here to help each member of your family with their dental needs, anywhere from a standard cleaning to emergency dental care. Whether it’s the youngest member of your family or the oldest, Dr. Canesi is here to help shape your family’s smiles.

Ryan Canesi

DMD, General Dentist

While studying biology at Boston College, Dr. Ryan Canesi found his love for dentistry while he volunteered at the dental clinic at the East Boston Community Health Center. Once he graduated, he moved on to earn his Doctor of Dental Medicine degree from Tufts University School of Dental Medicine. Dr. Canesi strives to provide a quality and caring dental experience for his patients using the latest technologies. Dr. Canesi is passionate about continuing to educate himself in the field of dentistry and values staying up to date on the latest techniques, trends, and treatments. He is proud to be a member of the American Dental Association and the Massachusetts Dental Society.

Dr. Ryan Canesi specializes in general dentistry. He is here to help each member of your family with their dental needs, anywhere from a standard cleaning to emergency dental care. Whether it’s the youngest member of your family or the oldest, Dr. Canesi is here to help shape your family’s smiles.

Gina Lightner

DMD, General Dentist

Gina Lightner, DMD, grew up in Northborough, Massachusetts and earned a Bachelor of Arts in Kinesiology with a concentration in Sports Medicine and a Bachelor of Arts in Philosophy from Rice University. Dr. Lightner earned her Doctorate of Medicine in Dentistry from the Tufts University School of Dental Medicine in Boston, Massachusetts. During her time at Tufts Dental, Dr. Lightner was recognized on the Dean’s list for her academic achievements, and she was inducted into the Honus Civicus Society for her exceptional commitment, leadership, research, and action in community service and civic engagement. Dr. Lightner went on to complete a General Practice Residency at Mount Sinai Hospital in Manhattan, New York, where she received advanced training in emergency dentistry, hospital dentistry, digital dentistry, aesthetic dentistry, and implant dentistry in various private, community, and hospital clinics across New York City. Dr. Lightner also served as first-call for the Mount Sinai Emergency Department on the Upper East Side in Manhattan as an on-call member of the Mount Sinai Oral and Maxillofacial Surgery team, where she also completed rotations in anesthesiology, internal medicine, pediatric dentistry, and medically advanced dentistry. Dr. Lightner is also a certified Invisalign provider, with a focus on addressing orthodontic relapse and cosmetic alignment.

Dr. Lightner loves getting to know her patients and continuously expanding her knowledge of dentistry to best serve her patients’ needs. Dr. Lightner is a proud member of the American Dental Association, Massachusetts Dental Society, and the Academy of General Dentistry.

Kathleen C. Mascardo

DMD, MMSc, Periodontist

Growing up in a family of dentists, Dr. Mascardo was exposed to oral surgery and dental implants at an early age. She draws inspiration from her parents who pioneered in bringing oral implantology to Southern Philippines in the early 1990s. This long legacy of patient care led her to develop a passion for surgical procedures, which brought her to the Northeast in search of the highest level of education and clinical training.

Dr. Mascardo holds two Doctor of Dental Medicine (D.M.D.) degrees from the Davao Medical School Foundation and the University of Pennsylvania School of Dental Medicine. Upon graduating from DMSF in 2013, she placed 6th out of nearly 1,000 examinees in the rigorous Philippine Dental Board Examinations and was given the Presidential Scholarship Award for exceptional achievement. In 2019, she graduated at the top of her class from the University of Pennsylvania with a full spectrum of honors and awards in Periodontics, Endodontics, and Prosthodontics, which culminated with an induction into the prestigious Omicron Kappa Upsilon (OKU) Honor Society.

Dr. Mascardo ultimately followed her passion and pursued a surgical specialty to further elevate her comprehensive multispecialty training. She graduated from the Harvard School of Dental Medicine with a Certificate in Periodontology and Master of Medical Sciences in Oral Biology (MMSc). She worked extensively with other dental specialties in treating complex cases and was distinguished with the American Academy of Implant Dentistry (AAID) Award for having demonstrated exceptional academic and clinical achievement in Dental Implantology.

With over 10 years of experience, Dr. Mascardo is known for her gentle touch and caring approach. She is skilled in all aspects of periodontal surgery, extractions, soft tissue grafting, sinus lifts, laser therapy, peri-implantitis management, and full-arch dental implants. She has a special interest in the use of growth factors for periodontal regeneration and extensive bone grafting procedures. Above all else, she practices with empathy, compassion, and honest communication when treating patients. She appreciates the trust that patients and referring dentists have put in her hands, and she is excited to provide the highest level of periodontal care to our greater community.

Outside of Dentistry, Dr. Mascardo is a former soccer varsity player, as well as an artist, writer, and foodie. She owned a restaurant for 7 years (ended only by covid-19) and has a great love for travel, food, and discovering different cultures through its cuisines. She is equally passionate about charitable causes that advocate for women, children, and people with disabilities. Throughout the years, she has spearheaded charity missions to deliver much needed services to the Davao School for the Blind and Southern Philippines Medical Center – House of Hope Children’s Cancer Center. Dr. Mascardo is a strong believer in the healing power of compassionate human touch, which she strives to practice in everyday patient care.