Background: The Department of Veterans’ Affairs (VA) operates 146 hospitals providing healthcare to >6 million veterans annually, including dental care to qualified veterans. Although bloodborne pathogen transmission after dental procedures is rare, little is known of risk when there are breaches. A standardized approach to performing lookback investigations after dental infection control breaches could better quantify these risks. We reviewed dental lookback investigations from the past decade conducted by our VA office for lessons learned to improve processes. Methods: Three VA hospitals had dental infection control breaches during 1992–2016. Facility A had dental instruments that were not cleaned according to the manufacturer’s recommendations, and dentists at facilities B and C failed to adhere to proper infection control standards. Exposed veterans who underwent dental procedures were notified of possible exposure and were offered testing for human immunodeficiency (HIV-1), hepatitis B virus (HBV), and hepatitis C virus (HCV). Prior clinical testing was also reviewed. Newly identified positive results were compared to known positives prior to exposure to determine strain relatedness when sufficient plasma viral load was present for viral sequence comparison. Results: There were 2,939 patients with potential exposures in these dental investigations: 2,667 were tested for HBV, 2,642 were tested for HCV and 2,599 were tested for HIV-1. No evidence of viral transmission was found based on genetic sequence comparison of positive cases, but relatively few samples were available for this testing. Lessons Learned: Each facility faced different challenges with their investigation; however, several key processes were identified. (1) Early engagement by our office with local facility leadership and lookback teams resulted in more efficient investigation and testing processes. (2) To improve standardization, a lookback manual detailing of investigation procedures was created in 2009 and was updated subsequently. The contents of this manual include identifying and notifying patients; providing services to veterans responding to notifications; laboratory testing algorithms; disclosure and documentation of test results and clinical follow-up; and epidemiologic investigation of patients with newly identified infection. (3) Prompt patient notification and obtaining adequate samples for initial and follow-up pathogen genetic testing is critical. Determination of genetic linkages was greatly limited because specimens were unavailable for supplemental testing. (4) Ethics and legal counsel staff are key partners in providing guidance on appropriate disclosure procedures and documentation. (5) Designating a single mechanism for reporting results ensures consistent communication among stakeholders. (6) Education of dental staff on importance of following the manufacturers’ cleaning recommendations, not using outside equipment and reporting instances of concern promptly can help prevent future infection control breaches.