Snottites, phlegm balls, biofilm

Dec. 1, 2005
Debridement cannot be rushed, and the era of 30- to 50-minute adult dental hygiene maintenance visits for periodontal and healthy patients is over.

Debridement cannot be rushed, and the era of 30- to 50-minute adult dental hygiene maintenance visits for periodontal and healthy patients is over.

Flu season is a scary time for lots of people, especially those with chronic respiratory illnesses. People are hacking and coughing in public places. Even if you rub your hands constantly with an alcohol-based hand rub, droplets from the cough or sneeze of an infected person can be propelled through the air (with the greatest of ease!) and deposited in the mouth or nose of people nearby. Once infected, the production of phlegm that eventually accumulates in your throat after endless coughing is nothing short of totally repulsive.

What about phlegm that is produced in underground caves? Have you ever heard of such a thing? Well, neither had I until I read about the mystery of cave formation.

Here’s the scoop. Within caves, stalactite-like structures have been discovered that ooze with a slimy goo that literally drips sulfuric acid. These bizarre formations are referred to as “snottites.” A molecular analysis has found that these snottites are brimming with sulfur-loving bacteria.

In addition, there are other globs of microbes, appropriately referred to as “phlegm balls,” that live in underground streams in the cave. These subterranean microbial communities play a significant role in cave formation. These ingenious little buggers produce acid that dissolves the cave’s limestone walls, and as the lining of the cavern is slowly sloughed off, the cave (cavern) expands!

So, what do snottites, phlegm balls, and biofilm have in common? All three slimy and gooey substances can survive in extremely hostile environments. Biofilm formation is a mode of growth for bacteria that allows these microscopic critters to live in hostile environments and to reproduce to form new niches.

Biofilm science has become quite sophisticated as a result of studying biofilms over a period of 25 years or more. We now know a lot about medical implant-related infections that have resulted from sophisticated biofilm communities that adhere to the surface of the implant. Once inside the biofilm, the bacteria are much more resistant to antibiotic treatment and are sometimes only resolved by removing the contaminated implant.

Let’s now focus on oral biofilms and what we know about them that will assist hygienists in understanding their role as “super-slim-ultrasonic-insert-yielding biofilm destroyers who sweep the sulcus with great speed and accuracy.” What did I say? You heard it right - only the dental hygienist, with instrument in hand, can remove these sticky bacteria-laden films and destroy them.

In developing a better understanding of biofilms, I recently Googled my way to the Montana State University, Center for Biofilm Engineering Web site. ( There are some pretty amazing biofilm movies to view online. I was particularly fascinated by the 3D computer simulation cellular model that showed the response of a microbial biofilm to an antimicrobial treatment. We now know, based on years of research, that bacteria living in dense, complex biofilms are remarkably resistant to antibiotics, antimicrobials, and host defense mechanisms, especially as biofilms age. Teeth provide a unique habitat because teeth are nonshedding surfaces that allow for the development of very thick biofilms.

In treating early to moderate periodontitis nonsurgically, the removal of established biofilms from subgingival areas, combined with supplemental antimicrobial agents, is an essential part of nonsurgical therapy. Subgingival biofilms in individuals with periodontitis as compared to healthy individuals are markedly different. Individuals with periodontitis have more subgingival counts of bacteria in the red and orange complexes and these complexes didn’t settle in overnight. Just as it takes a homeowner several years to get completely settled into a new home, the colonizing species develop a sophisticated biofilm community that is not easy to disrupt, especially in deep pockets and in furcations. In addition, the numbers of the red and orange complexes are elevated at deep sites that bleed on probing.

In the middle of the last century, acute epidemic diseases such as diphtheria, gangrene, and cholera predominated and are now controlled by vaccines and antibiotics. These acute infections were caused by planktonic (free-floating) bacteria, and microbiologists can be credited with their demise. These free-living, free-floating drifters eventually become members of established communities. In fact, some researchers think that the free-floating drifters may be nothing more than bacterial cells that have broken away from biofilms and are searching out new habitats. Subgingival oral irrigation using a subgingival tip can keep planktonic bacteria in check, up to about a depth of 6 to 7 millimeters. Perhaps regular home subgingival irrigation can assist in preventing these free-floating drifters from creating new biofilm homes.

At the American Academy of Periodontology Dental Hygiene Symposium last September, Anna Pattison, RDH, spoke briefly about biofilm. She talked about the use of endoscopy in visualizing residual biofilm and burnished calculus in root depressions, furcations, and at the CEJ. According to Ms. Pattison and periodontal researchers at the London Eastman Dental Institute, biofilm appears to recolonize faster in areas with burnished calculus. She also mentioned evidence of residual inflammation on the soft tissue wall opposite the burnished calculus, which is why clinicians find bleeding in areas with burnished calculus.

The National Institute of Dental and Cranial Research, part of the National Institutes of Health (NIH), is supporting a three-year study to compile a catalogue of genes found in biofilms. The next big leap forward may be the identification of genes that can be used as “promising targets of activity” for new pharmaceutical drugs that can destabilize biofilms or possibly even arrest their activity.

So what have we learned to date about oral biofilms that we can apply to periodontal therapy? First, thorough root debridement is essential to reduce putative pathogens in biofilms along with calculus, including burnished deposits. Debridement cannot be rushed. The era of 30- to 50-minute adult dental hygiene maintenance visits for periodontal and healthy patients is over. Effective ultrasonic scaling and hand instrumentation takes time. We now have a wonderful variety of magnetostrictive and piezoelectric inserts that are designed to target biofilms and calculus in deep pockets and furcations.

In addition, periodontal endoscopy allows for visual access to root surfaces, lessening the need for surgical intervention in many instances. Second, it is important to remember that antimicrobials in the form of locally delivered antimicrobials or antiseptics delivered through subgingival irrigation can reduce the total microbial load with varying amounts of substantivity but do not penetrate subgingival biofilms.

The mere presence of putative pathogens in the red and orange complex in biofilms does not necessarily lead to destruction of the periodontium in the host but it is possible that bacterial levels must reach a critical threshold in order to induce irreversible host tissue destruction. Therefore, meticulous debridement for susceptible individuals on a consistent basis along with optimal home care is essential. Who better to provide these essential services than the dental hygienist, especially one who is trained in evidence-based periodontal therapy and committed to continual, self-directed learning?

Bring on the snottites, phlegm balls, and biofilms ... we can tackle them all!

Lynne H. Slim, RDH, BSDH, MSDH, is a practicing hygienist/periodontal therapist who has more than 20 years experience in both clinical and educational settings. She is also President of Perio C Dent Inc. (Perio-Centered Dentistry), a practice management consulting firm that specializes in creating outstanding dental hygiene teams. Lynne is a member of the Speaking and Consulting Network (SCN) that was founded by Linda Miles and has won two first place journalism awards from ADHA. Lynne is also owner/moderator of a periodontal therapist yahoo group: She can be contacted at [email protected].