Letters from a national dental and vision insurer hit mailboxes Monday informing patients, including residents of Western Pennsylvania, of a data breach potentially involving their personal information.

The Virginia-based insurer Dominion National, which is part of the UPMC Health Plan, according to the company's website, announced a “security incident” that could compromise information stored about its members.

“On April 24, 2019, through our investigation of an internal alert, with the assistance of a leading cybersecurity firm, we determined that an unauthorized party may have accessed some of our computer servers,” the company announced Monday in a news release.

The release went on to report that the data breach might have occurred as early as August 2010.

According to its website, Dominion National provides dental plans and administrative services to UPMC Health Plan members and maintains an extensive selection of participating dentists.

“After learning of this, we moved quickly to clean the affected servers and implement enhanced monitoring and alerting software. We also contacted the FBI and will continue to work with them during their investigation,” the company said on its website.

Dominion National sent letters Friday to members who could have been affected by the security breach.

Membership information that could have been compromised includes names, addresses, email addresses, dates of birth, Social Security numbers, member ID numbers, group numbers and subscriber numbers.

According to the company, for customers enrolled in the company's online services, bank account and routing number information could also have been breached.

“We have no evidence that any information was in fact accessed, acquired or misused,” the release said.

The company has established a dedicated incident response line to answer any questions. The incident response line is open Monday through Friday, 8 a.m. to 8 p.m., and can be reached by calling (877) 503-8923.