Antibiotics before teeth cleaning not recommended

Dear Dr. Roach: I have had two angioplasty procedures completed, one in 1999 and the second in 2014. Stents were inserted during each procedure. As a preventive measure, my dentist wants me to take four antibiotic pills (amoxicillin) before I see the hygienist. What is the reason for this? Do you feel it is necessary to take antibiotics before each visit to the hygienist? — E.L.S.

Answer: Antibiotic prophylaxis is not routinely recommended for people with cardiac stents. The risk of infection is very low, probably lower than the small risk of an adverse event from the antibiotics. It’s not clear that taking antibiotics would even reduce this already small risk.

People with some cardiac problems, such as a prosthetic heart valve, some types of congenital heart disease or a prior history of infection of the heart valve should take antibiotics. But, in general, antibiotics for a low-risk person are not recommended.

Of course, I would get assurance from your cardiologist that there is not something distinct about your case, but from what you have told me, I wouldn’t recommend antibiotics.

Dear Dr. Roach: On a recent exam, I was found to have a low urine specific gravity (the normal range was 1.010 to 1.030, and my level was 1.005). What does this mean? Is this a problem? — S.M.

Answer: Urine is water with the metabolic byproducts that your body wants to get rid of, along with a certain amount of salts, depending on your consumption. The specific gravity is a way to look at how concentrated the urine is. A very high number (1.030 or higher) indicates that the kidney is trying to conserve water: It’s likely that the person needs fluid. In people who drink a lot of fluid, the kidney must make a dilute urine: 1.010 or lower. With your result, it is clear that you drink a lot of water, and it’s very likely that your kidneys work well.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible.