This clinical trial is studying if bacteria found in a participant's bloodstream after brushing their teeth can be prevented with a dental cleaning and more education on how to best brush and care for their teeth. One group of participants will have a dental cleaning and oral health instructions and the other group of participants will not. Researchers will compare the blood test results from the two groups to see if the education made a difference in preventing bacteria and how long it stays in the bloodstream.

This multi-center randomized clinical trial will determine if an intervention to improve oral hygiene and reduce gingival inflammation decreases the incidence and duration of bacteremia of Infective Endocarditis (IE) causing bacterial species, which may refocus longstanding guidelines on prevention for all people at risk for Infective Endocarditis (IE). The Standardized Brushing Hygienist will brush the participant's teeth over a 2-minute period, during and after which there will be 4 additional blood samples. The participant will then be randomized to an intervention or routine care group. The intervention will consist of a single session of tooth scaling and polishing, and oral hygiene instruction provided at the end of the Randomization Visit. Both groups will return for 3-week and 15-week visits, during which they will undergo a non-invasive oral examination and the brushing procedure with 5 blood samples (baseline and 4 additional blood samples after brushing begins). All blood samples will be cultured for bacteria of IE causing species.

Inclusion Criteria:

• Age 18 years or older.
• Greater than 6 months since last dental hygiene prophylaxis (cleaning).
• 10 or more accessible teeth (including implants, with a minimum of 8 natural teeth).
• Willing and able to provide informed consent.
• Willing to comply with all study procedures and be available for the duration of the study.
• Willing to forgo routine professional dental cleanings while enrolled in the trial.

Exclusion Criteria:

• At high risk for IE, as defined by the 2007/2021 AHA Guidelines:
• Prosthetic cardiac valve or prosthetic material used for cardiac valve repair.
• Previous episode of IE.
• Cardiac transplantation recipient with cardiac valvulopathy.
• Specific congenital heart disease conditions.
• Pregnant, by self-report, or planning to become pregnant during the study period.
• Affected by a condition that, in the opinion of the investigator, may preclude them from study completion or put them at increased risk such as :
• Hemodialysis dependent.
• Have a long-term intravascular catheter (e.g., for chemotherapy or parenteral nutrition).
• Active injection drug use (IDU).
• Clotting disorder such as, hemophilia.
• Have a solid organ transplant or hematopoietic stem cell transplant, or ongoing treatment for hematologic cancer.
• Currently incarcerated.
• Systemic antibiotic use within the past 2 weeks.
• Undergoing orthodontic treatment with fixed appliances (brackets and wires) or plans to do so during the study period.
• Taking or requiring antibiotic prophylaxis prior to dental procedures for other reasons, e.g., to prevent prosthetic joint infection .
• Three or more teeth with moderate to severe gingival hyperplasia.
• Has clinically detectable emergent or urgent dental needs that, in the trained and calibrated Oral Examiner's opinion, would require definitive dental care during the study period.

A public use dataset will be available upon study completion.