Northborough, MA Bret O’Brien and Mitchell Stepien of Greater Boston Commercial Properties, Inc. (GBCP)sold 1 East Main St. for $3.1 million. The 30,000 s/f office property was constructed in 2001 as a dental related medical center that included general dentistry, orthodontics, oral surgery and a periodontist. Nineteen years later the tenant roster still includes general dentistry and orthodontics as well as a financial planning office and a pediatrician’s office. With roughly over one third of the space remaining vacant the new owner plans to focus on attracting more medical tenants. 1 East Main St. represents the third office building sale that GBCP has completed this year in the three million dollar range, after selling 19 Forest St. in Marlborough in January for $2.98 million and 221 Boston Post Rd. East in Marlborough in April for $3.45 million. GBCP was the sole broker of record representing the seller and procuring the buyer.