Welcome to Smiles of Groton,

formerly the dental practice of Dr. Peter Breen, DMD.

We are Drs. Marc and Molly Valli and we are very excited to be the new owners of this exceptional practice! We are thrilled for this opportunity and feel very fortunate to be establishing ourselves in the wonderful town of Groton. Dr. Breen has served the community for 29 years and we wish him all the best in his retirement!

Our practice philosophy is well-aligned with Dr. Breen’s, and at Smiles of Groton, we will continue to provide honest, high-quality dentistry to our patients. We take pride in working with all patients to accomplish their individual goals, treating them as we would our own family. In addition, we want our patients to know that dentistry can be a pleasant experience, where treatment is provided in a gentle, efficient and caring manner.

Dr. Breen has spoken very highly of the long-standing patient relationships that he has built over the years, as well as the pride that he feels for Groton and surrounding communities. We want to build on these relationships, where we get to know you on a personal level as well, and take care of you and your family for many generations! 

Please explore our website for more information about usour services, and what sets us apart. 

Experienced Dentists and Team

Quality and Pain-Free Dentistry

Comprehensive Range of Services

Modern Technology

We Listen

Our Patient Testimonials

“I was very impressed with the Smiles of Groton dentist office in Groton, Ma. I felt Molly the dentist was very friendly and a very honest person with her review of what needed to be done with my teeth. Emily the Hygienist also was very nice and did a good job cleaning my teeth and taking xrays. Amy the receptionist was very helpful in getting me a prescription.” — Ramona Nov 7, 2020

“I used to hate going to the dentist. But I mean it when I say I look forward to it now. I love to go! The care, the bedside manner, its all superior to what I used to go to!” — Emily Oct 8, 2020

“Everyone was very professional. There wasn’t a wait. All processes were painless and my favorite scold-free!” — Tracy Sep 23, 2020

“This was my first encounter in this office, and my first experience visiting a dentist since the start of the COVID pandemic. I felt comfortable with the pandemic adaptations they made. Everyone was friendly and professional, and their communications are excellent.” — Cathy Sep 17, 2020

“Excellent service, clean and friendly.” — Keith Sep 2, 2020

“Quality service with a smile. Very professional office with a friendly staff. State of the art equipment. What more could you ask for?” — Dennis Aug 26, 2020


MON 9:00 AM – 7:00 PM

TUE 7:00 AM – 4:00 PM

WED 7:00 AM – 5:00 PM

THU 7:00 AM – 4:00 PM