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Dr. Nichol Penna, owner of Dunstan Dental Center in Scarborough, Maine
Dr. Doug Delli Colli, owner of Dunstan Dental Center in Scarborough, Maine

Douglas Delli Colli, DMD

Dr. Nichol Penna and Dr. Doug Delli Colli are proud and thankful to be able to continue Dunstan Dental Center’s ownership as a family-run dental practice that specializes in caring for local families and patients of all ages. Dr. Nichol’s parents, Dr. Joseph Penna and Dr. Demi Kouzounas, opened Dunstan Dental Center in 1986 when Dr. Nichol was a young child.  Although the dental office was like a second home to her, she never fathomed that one day she and her husband would continue ownership of the practice while raising a family of their own. After several years of partial ownership with her parents, Dr. Nichol and Dr. Doug transitioned to become full owners of Dunstan Dental Center in 2021.

Dr. Nichol Penna was raised in Saco, Maine and graduated from Thornton Academy in 2002. She continued her education at Colby College in Waterville, Maine and graduated in 2006 with a major in Biology and minor in Chemistry. Dr. Nichol continued her education at Tufts University School of Dental Medicine. It was at Tufts that she met her future husband, Dr. Doug Delli Colli.

Dr. Doug Delli Colli was raised in Pepperell, Massachusetts and graduated from North Middlesex Regional High School in 2001. He furthered his education at the University of Massachusetts Amherst and graduated with a degree in Microbiology in 2005. Upon graduation he entered Tufts University School of Dental Medicine and completed his degree in 2009.

Dr. Nichol and Dr. Doug enjoy spending time with their two young daughters. As a family, they enjoy what Maine’s four seasons have to offer and try to get outside to experience them all. Dr. Doug is a muscle car enthusiast and enjoys taking the family out to cruise nights and car shows during the warm months.

Dr. Doug and Dr. Nichol both enjoy furthering their education and find continuing education courses and local study clubs to be essential to their practice. Both are active members in the Greater Portland Dental Society, Maine Dental Association and American Dental Association. They are members of their local Spear Study Club and have enjoyed several mini residency programs together. Dr. Doug enjoyed several years as Adjunct Faculty at the University of New England Dental Hygiene School as a clinical supervisor. They take pride in providing their patients a comfortable experience and maintaining their patients’ trust. They enjoy providing full dental care to patients of all ages starting from 6 months old and continuing throughout their golden years. The personal connections they establish with their patients continues to drive them forward. They plan on continuing to bring new education and technology to their practice to offer to their patients the best experience possible.  


Nichol Penna, DMD

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