Breaking Down Biofilm
Advances in prevention and control
Catherine Paulhamus, MA
The message was once focused on plaque removal. Patients were advised by dental hygienists, dentists, and pharmaceutical marketing to remove this deposit from oral surfaces regularly through brushing and flossing. Every 6 months, hygienists would evaluate their plaque control and eliminate further accumulations mechanically. This message was simple and straightforward: clean vigorously and often to thwart bacteria.
As with other advice from the past, the message has changed as research revealed more about the complex interactions that promote—or undermine—health. For dental hygienists and their patients, the focus has shifted to oral-systemic health, which includes the role of biofilm.
Biofilm is now understood to be a highly organized microbial community, which cooperates to prevent attempts to eradicate it.1 Its structural bonds result in an almost "irreversible" attachment to surfaces. However, once it forms, it is not limited to its original location. Pieces break off and flow to other sites, to begin new communities or impact systemic health.1 Biofilm is found not only on tooth surfaces, but also on restorations, orthodontics, implants, the tongue, and gingival tissues.2 After removal, either professionally or through home care, biofilm is quick to reform—and therefore difficult to prevent.
Bacteria within biofilms initiate an immunoinflammatory response, resulting in soft- and hard-tissue destruction and periodontal disease. A bidirectional interaction between periodontitis and systemic health conditions has been well-established.3 The American Academy of Periodontology explains that although a causal relationship has not been proven, research suggests that periodontal disease contributes to the progression of other disorders, including diabetes, cardiovascular and respiratory diseases, cancer, and Alzheimer's.4
While this new understanding of biofilms and oral-systemic links was being integrated into health care, the medical community was also reassessing the role of the human microbiome. The human body has 10x more organisms (including bacteria, fungi, viruses) than human cells. These organisms are highly diverse, located mostly in the digestive system, and their activity is important to maintaining health, in ways that are not yet fully understood.5
In 2007, the National Institutes of Health announced the launch of the Human Microbiome Project, to explore role of microbes in human health and disease.6 Researchers will use new, comprehensive laboratory technologies to characterize the microbial communities present in samples taken from healthy human volunteers, even for microbes that cannot be grown in the laboratory. Demonstration projects will subsequently be funded to sample the microbiomes from volunteers with specific diseases. This will allow researchers to correlate the relationship between changes in a microbiome present at a particular body site to a specific illness.
The project's goal is to discover what microbial communities exist in different parts of the human body and to explore how these communities change in the presence of health or disease. In addition, the discovery of novel genes and functional elements in microbial genomes will reshape the way clinicians understand and approach human biology.6
"In the past, many health care strategies focused on eliminating all bacteria," says Mia L. Geisinger, DDS, MS. "But now we recognize that some bacteria promote well-being. Strategies are shifting to encourage the symbiotic microbiome that allows for health."
Beyond Mechanical Removal
Clinicians are acknowledging that biofilm is nearly impossible to control mechanically, as it quickly recolonizes. In addition, microscopic biofilm must first be perceived to be removed through instrumentation. More comprehensive approaches have been proposed to interrupt biofilm formation and attachment.7 Rather than treat all bacterial species equally, for example, chemotherapeutic treatments could impede biofilm formation, while allowing beneficial bacteria to flourish.
Research on the efficacy of new products and protocols is extensive. For home care, the focus is on strategies such as oral irrigation, probiotics, and mouth rinses with essential oils, Chlorhexidine gluconate (CHX), Delmopinol hydrochloride (HCL), or Cetylpyridinium chloride (CPC).
For professional care, more advanced technology for hygienists is being explored, including ultrasonic scaling, various dental lasers, and low-abrasive air polishing systems using glycine or erythritol powders. Leading-edge research is advancing even more high-tech designs for biofilm removal, such as photodynamic therapy and nanoparticle robots.8,9
Using advanced technologies and other innovations, practitioners can rethink biofilm control, Geisinger explains. "Mechanical removal—scaling—used to be the standard. Now we have more exciting options. For example, there's emerging data about some of the ways to personalize patient oral hygiene, such as microbial sampling in office. Instead of trying to remove all bacteria, we could change the oral environment, making teeth less susceptible to biofilm adhesion."
Hygienists are at the forefront of preventing diseases, she adds. "We are fundamentally overall health care providers. We are the educators for our patients, because prevention is equally, if not more, important than procedures. And we realize that nothing we do can be successful without daily biofilm control."
Focus on Oral Microbiome: Recent Findings
Some Oral Bacteria Linked with Hypertension in Older Women
Journal of the American Heart Association Report (March 2, 2022)
In a study of more than 1,200 women in the U.S., average age 63 years, 10 kinds of oral bacteria were associated with a higher risk of developing high blood pressure, while five strains of bacteria were linked with lower hypertension risk. The observational study cannot prove cause and effect; however, the findings highlight possible opportunities to enhance hypertension prevention through targeted oral care, researchers said.
Evidence Grows for Vaping's Role in Gum Disease
New York University College of Dentistry (February 22, 2022)
The latest research finds that e-cigarette users have a unique oral microbiome—the community of bacteria and other microorganisms—that is less healthy than nonsmokers but potentially healthier than cigarette smokers and measures worsening gum disease over time. Researchers are beginning to understand how e-cigarettes and the chemicals they contain are changing the oral microbiome and disrupting the balance of bacteria.
SARS-CoV-2 RNA in Dental Biofilms: Supragingival and Subgingival Findings From Inpatients in a COVID-19 Intensive Care Unit
Journal of Periodontology (March 3, 2022)
This study concluded that "ICU patients harbored SARS-CoV-2 RNA in supragingival and subgingival biofilms, irrespective of the periodontal condition and systemic viral load. The high number of positive patients highlights the need to better understand this habitat to provide adequate oral care."
Living in a Microbial World: The Healthy Oral Microbiome Contributes to Jaw Bone Health
Medical University of South Carolina (February 16, 2022)
Several recent studies have demonstrated the contribution of the microbiome to regulating immune cells that influence bone health. Results from this MCSU study showed that healthy microbes in the mouth activated a subset of immune cells within the alveolar bone marrow, which in turn promoted osteoclastic cells that are responsible for breaking down bone.
Explosion in Microbiome Research Opens Door to a New Age of Medicine
Politico EU - Silent Killers: editorial series on chronic disease (February 21, 2022)
"Tomorrow's doctors won't just treat the disease; they will care for the super-organism—the totality of DNA in the patient sitting in front of them. A small desktop machine will spit out a personalized health plan, designed to boost and maintain health by promoting a thriving and perfectly balanced microbiome—the army of organisms in the gut, mouth and on the skin—and body."
Oral Microbiota in Human Systematic Diseases
International Journal of Oral Science (March 2, 2022)
"The microenvironment at different sites in the oral cavity has different microbial compositions and is regulated by complex signaling, hosts, and external environmental factors. These processes may affect or reflect human health because certain health states seem to be related to the composition of oral bacteria, and the destruction of the microbial community is related to systemic diseases."
Gum Disease Increases Risk of Other Illness Such as Mental Health and Heart Conditions, Study Suggests
University of Birmingham (December 20, 2021)
"The researchers examined data to establish how many of the patients with and without periodontal disease go on to develop cardiovascular disease (e.g., heart failure, stroke, vascular dementia), cardiometabolic disorders (e.g., high blood pressure, Type 2 diabetes), autoimmune conditions (e.g., arthritis, Type 1 diabetes, psoriasis), and mental ill-health (e.g., depression, anxiety and serious mental illness)."
1. Kurtzman GM. Understanding oral biofilm. Inside Dentistry. 2016;12(10):48-55.
2. Miller N. Biofilm Conquered: Glycine Powder to The Rescue! Oral Health Group Web site. https://www.oralhealthgroup.com/features/biofilm-conquered-glycine-powder-to-the-rescue/. May 28, 2019. Accessed March 2, 2022.
3. Shi M, Pizzini A, Geisinger ML. Effects of micronutrients on periodontal health and disease. Inside Dentistry. 2021;17(11):33-37.
4. Gum Disease and Other Systemic Diseases. American Academy of Periodontology Web site. https://www.perio.org/for-patients/gum-disease-information/gum-disease-and-other-diseases/. Accessed March 1, 2022.
5. Moldovan S. Microbes and their role in the oral-systemic connection: a review of recent literature. Compend Contin Educ Dent. https://cced.cdeworld.com/courses/5266-microbes-and-their-role-in-the-oral-systemic-connection-a-review-of-recent-literature. Accessed February 27, 2022.
6. NIH Launches Human Microbiome Project. National Institutes of Health Web site. December 19, 2007. https://www.nih.gov/news-events/news-releases/nih-launches-human-microbiome-project. Accessed March 7, 2022.
7. Donley T. Rethinking the goal of patient-driven and therapist-provided debridement. Compend Contin Educ Dent. 2020; 41(5):290-291.
8. Wang Y, et al. Construction of nanomaterials with targeting phototherapy properties to inhibit resistant bacteria and biofilm infections. Chemical Engineering Journal. 2019;358:74-90.
9. An Army of Microrobots Can Wipe Out Dental Plaque. Penn Today. https://penntoday.upenn.edu/news/army-microrobots-can-wipe-out-dental-plaque, April 24, 2019. Accessed February 26, 2022.