Dental biofilm – a case of life or death?

It’s estimated that half of the world’s adult population have some degree of gingivitis. In the UK, 10-15% of adults have severe periodontitis (NHS Choice, 2014) and about 31% of adults and a third of children 12 years of age and under suffer from tooth decay (NHS Choices, 2012). The latest report from the Department of Health found the levels of gingivitis and tooth decay amongst children in the UK are as bad as they were in 1983. These common oral health problems can in fact all be traced back to one culprit – dental biofilm.

It’s only recently that plaque has been recognised as a biofilm. This recognition has given the dental community a better understanding of how dental biofilm forms and develops and how it can affect the rest of the body.

Biofilm starts with the attachment of bacteria onto the tooth surface within minutes after a professional cleaning. The bacteria go on to develop into microcolonies and mature and colonise in the subgingival and interdental area. Hundreds of different bacteria with differing physiological needs can survive. Biofilm is a perfect haven for pathogens to thrive within a living host, while being immune to the host's natural defences and highly resistant to traditionally administered antibiotics (Riddle, 2001). 

Oral biofilm is normal and not always harmful when balanced. Biofilm is believed to become cariogenic when certain conditions change and the biofilm is under stress, eg, when there is an increase of fermentable sugars in the patient’s diet and the biofilm is continually exposed to lower pH. This propagates the dominance of acidogenic and acid-tolerating species, such as mutans streptococci and lactobacilli increasing the risk of caries (Marsh, 2005). In periodontal disease, mature biofilm is the aetiology for gingivitis progressing to periodontitis if left (Mealey, 2004).

Biofilm carries more than 500 species of bacteria within its matrix (Nield-Gehrig), but only 20 or so strains are pathogenic, such as P gingivalis, T forsythensis, and Prevotella intermedia (Haraszthy, 2000). Studies have found periodontal pathogens like these in other organs of the human body as well, leading researchers to make a connection between periodontal disease and other health issues like heart disease (Herzberg, 1996), low birth weight babies (Offenbacher et al, 1996) and diabetes (Mealey, 2003). 

Periodontal microorganisms found in atheromatous plaque provide the most direct evidence of the connection between dental biofilm and systemic inflammation (Chiu, 1999). Pathogens, such as Pseudomonas aeruginosa, Staphylococcus aureus and enteric bacteria may work their way into the lower airway through saliva, causing respiratory infection (Scannapieco, 1999). Periodontitis has been identified as one of the leading complications of diabetes (Löe, 1993) and research suggests maintaining glycemic control can be more difficult for diabetics with periodontitis than those with good oral health (Taylor, 1996).

Ensure treatment

Due to the myriad of serious infections and diseases it is linked to, it is important dental biofilm is not left untreated. Because biofilm develops so rapidly and can spread subgingivally and interdentally, it is impossible to eliminate biofilm from the mouth completely. Vigilant oral care can keep biofilm at bay, and professional debridement twice a year followed by an effective oral health routine is needed to ensure plaque biofilm doesn’t develop further.

Since most patients only see their dentists and dental hygienists every six months at most, the quality of the oral healthcare they practise is very important. Interdental cleaning and removal of plaque along the gingival margin are crucial routines. The importance of treating biofilm and the difficulties of removing it is heightened for patients who have additional challenges in their mouth.

Basic tools have always been recommended as part of good oral hygiene, but toothbrushes, mouthwashes, and traditional string floss alone cannot always provide the necessary thorough cleaning needed to keep plaque biofilm at bay. It may be best to recommend patients to practise meticulous oral cleaning techniques at home with products such as the Waterpik Water Flosser, clinically proven to reverse gingivitis (Barnes et al, 2005), remove plaque (Sharma et al, 2008) and reduce bleeding (Rosema, 2011).

Attentive oral care routines are widely accepted as the most effective method of preventing and managing gingivitis and periodontal disease, it’s crucial patients are made aware of their situation. It may seem dramatic to question whether biofilm can be a case of life or death, there is too much research highlighting its potential seriousness to ignore it. 


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