Mary is 74 years old and comes to the office every three months, like clockwork, for her cleanings. And every three months, her teeth are covered in plaque. We use hand mirrors and demonstrate brushing technique. We talk about improving her dietary choices and managing her dry mouth with sugar-free mints and lozenges. We stress the importance of her oral hygiene to preserve the abutment teeth for her partial denture.
And, oh, did I mention Mary only has four teeth?
We all have patients who, whether due to issues with dexterity, diet or medication-induced xerostomia, are constantly fighting a battle with plaque buildup and bleeding gums. Mary falls into all three categories, and despite her best efforts to maintain what’s left of her dentition, she’s gradually losing the battle.
Mary has been on chlorhexidine mouth rinses before, but due to cost, tooth staining and the effects on her sense of taste, it has been more of an on-and-off routine. I resigned myself to the fact that there wasn’t much more I could do or recommend.
However, this year I started hearing about the use of mouth rinsing with dilute sodium hypochlorite as an effective way of reducing dental plaque levels, and the idea piqued my curiosity enough to look more into the history and literature behind its use.
How can bleach reduce dental plaque levels?
Sodium hypochlorite, one of the main active ingredients in household bleach, has been used as an antibacterial agent since the mid-19th century, when doctors used to wash their hands with it and noticed dramatically-reduced disease transmission between patients. However, it wasn’t until 1920 that the first published use of sodium hypochlorite was documented in endodontic root canal therapy.
As a broad spectrum antimicrobial agent, sodium hypochlorite has long been studied on the anaerobic bacteria that cause endodontic infections, but in vitro studies done with 0.5 percent sodium hypochlorite solutions have shown it to also be effective against S. mutans, S. sanguinis and Lactobacillus acidophilus, all bacteria that can routinely be found in the oral environment.
Concentrated sodium hypochlorite can be extremely caustic and cause extremely damaging tissue destruction. But as most backpackers can tell you, bleach can be used to treat potentially contaminated water sources and still be safe to drink when properly diluted. New studies are being done that show that using highly diluted household bleach as a mouth rinse can cause a significant reduction in dental plaque formation and bleeding on probing sites without some of the side-effects of long-term chlorhexidine use.
A randomized control trial comparing the effects of swishing twice a week with 0.25-percent sodium hypochlorite (vs water) in addition to a person’s oral hygiene routine showed statistically significant improvements in plaque-free surfaces and the number of sites with bleeding on probing after three months. The only reported side effects had to do with the taste of the rinse itself.
Another study measured the effects of a 0.05-percent Clorox® rinse in lieu of brushing. The control group who only swished with water had statistically significant higher plaque-index scores, higher levels of gingival inflammation as measured by the Loe and Silness Index, and a higher amount of bleeding on probing sites. To me, the latter study seems to show a benefit to those patients who may not have the dexterity to properly break up the plaque biofilm via mechanical means alone.
This all sounded promising, but I could just imagine the blank stares I was about to receive from any patients to whom I recommended swishing with bleach. Patients seem to be all about any home remedy they can find, until their doctor recommends it. I remember getting similar reactions when I advised my mouth-breathers to try taping their lips shut before going to bed. Same as then, I knew if I wanted to get any semblance of compliance, I had to try it out myself.
How to dilute bleach for patient use
As mentioned before, household bleach is extremely caustic and dangerous, and needs to be properly diluted to be handled safely. Standard bleach is six percent sodium hypochlorite. The two studies I cited above were performed with 0.25-percent and 0.05-percent solutions. This means we would need to dilute it by a factor of at least 24.
Now, I don’t know about your patients, but this isn’t simple mental math for me. I’ve worked the conversions out so that if you add two teaspoons of the bleach to a cup of water, you’ll have yourself a roughly 0.26-percent solution.
Words of warning: make sure you’re using unscented, fragrance-free formulations and making each batch as fresh as possible. Also, please double-check the percentage of the sodium hypochlorite on your bottle; some “concentrated” versions contain over eight percent.
As I mixed up my first batch, my nostrils began to flare and my eyes started to water. I instantly began to doubt myself. I double-checked my math. I triple-checked to make sure I didn’t miss a zero. I couldn’t help feel like I was about to take a big sip of hot tub water. I set my timer for 30 seconds and began to swish.
Towards the end, I could feel a slight tingly feeling from the bubble formation, though nothing painful. The taste, however, was pretty awful - no way to go about sugarcoating it. I knew that I was unlikely to be able to convince anyone to willingly incorporate this into their regular routine. Later that day, after my taste buds had fully recovered, I decided to give it one more try, diluting my previous ratio in half, using one teaspoon per cup of water.
I was pleasantly surprised by how big of a difference that extra dilution made. Theoretically, at 0.13-percent sodium hypochlorite, I was still within the potentially effective range, and found the taste of bleach only barely detectable. A glimmer of hope!
While I don’t plan on implementing or recommending this regimen to all my patients right away, I would certainly keep it in my back pocket as a low-cost, twice weekly option for patients who cannot seem to improve their plaque levels, despite their earnest efforts. I look forward to seeing larger, long-term studies being done evaluating its efficacy as well as any potential adverse reactions or unintended consequences that may arise after prolonged use.
1. Spencer, H. R., et al. “Review: the use of sodium hypochlorite in endodontics - potential complications and their management.” British Dental Journal, vol. 202, no. 9, Dec. 2007, pp. 555–559., doi:10.1038/bdj.2007.374.
2. Crane A B. A practicable root canal technique. Philadelphia: Lea & Febinger, 1920.
3. Evans, A, et al. “Inhibitory effects of antiseptic mouthrinses on Streptococcus mutans,Streptococcus sanguinisandLactobacillus acidophilus.” Australian Dental Journal, vol. 60, no. 2, June 2015, pp. 247–254., doi:10.1111/adj.12330.
4. Galvan, M, et al. “Periodontal effects of 0.25% sodium hypochlorite twice-Weekly oral rinse. A pilot study.” Journal of Periodontal Research, vol. 49, no. 6, Dec. 2014, pp. 696–702., doi:10.1038/sj.bdj.2015.224.
5. Nardo, Rodrigo De, et al. “Effects of 0.05% sodium hypochlorite oral rinse on supragingival biofilm and gingival inflammation.” International Dental Journal, vol. 62, no. 4, Nov. 2012, pp. 208–212., doi:10.1111/j.1875-595x.2011.00111.x.
Dr. Imahn Moin, DDS. http://www.oaktreedentalcare.com/