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Biofilm Disruption

– keeping it simple

I don’t know about you, but when I trained, the lessons on plaque formation and pathogenicity were not my favourite subject. Committing to memory, seeminglyendless lists of unpronounceable bacteria accused of being implicated in dental disease bored me. But not now!!  If you have been keeping up with your CPD you will have noticed a ‘C’ change in how we talk about dental plaque – indeed we don’t even call it plaque anymore. Biofilm is the new plaque! Well, strictly speaking, it is still dental plaque that we now describe as a biofilm and not an insignificant amount of reverence is given over to this sticky stuff.

Our more recent understanding of how bacterial communities or biofilms develop and multiply suggest ideas for preventing or eliminating them. Standard antimicrobials often fail because they do not penetrate the biofilms fully, or do not harm all of the bacterial types within the established biofilm community. Dental unit water line contamination is an area where such protective mechanisms have resisted routine decontamination.

Improved techniques to investigate dental plaque biofilms have enabled researchers to study their behaviour and to identify the vast number of microorganisms that make up these hugely diverse biofilm communities. As the technology for visualising these specific biofilms evolves, so will our understanding of their intricacies, tenacity and vulnerabilities.

But don’t worry! there is still no one causative pathogen in periodontal disease. There remain at least six acting in a consortium that can lead to periodontitis and no single species has been linked to the disease in all cases. We also know from the European Federation of Periodontists that whilst perio progression in the worlds populations are similar we all have subsets of patients whose disease behaves differently, with different levels of attachment loss and progression.i The outcomes from the Worlds Workshop on Classification presented at Europerio 9  in Amsterdam in June of this year has given us a new classification system that seeks to better capture the important features and complexity of the disease. The new system provides a matrix for assessment that allows us to record the staging and grading of the disease to aid in assessing the risk of disease recurrence.  BUT the bottom line in periodontal disease is STILL about the mechanical disruption of the biofilm, or in other words, getting the patients to clean their teeth effectively!iiii

For caries control we stick with dietary modification where necessary and good old plaque control!  Getting the message across that plaque is the bad guy here is not easy though.  Despite the inclusion of oral health education in key stages one and two, we still have an unacceptable level of caries in our under-fives.

Biofilm disclosed
Fig 1. Disclosed mouth with two tone disclosing solution showing new and old plaque.

Socioeconomics aside…poor plaque control remains a key component of this disease and…recognising that effective plaque control is well within the capabilities of the majority is a step in the motivational direction for us all. Disclosing may be old hat but it remains a sure fire way of convincing a patient that they have ‘missed a bit’ . The use of micro brushes for disclosing solutions can make single site or quadrant applications simple and hygienic if a tad more expensive.  The messy but fun chew, spit, rinse technique for the traditional disclosing tablet remains a mainstay of the oral hygiene session in children of school age.

And for cleaning around the bend?

Interdental brushes used in combination with a toothbrush are more effective in the removal of plaque from proximal tooth surfaces than a toothbrush alone or in combination with dental floss.  Although, getting patients to clean interdentally, has always been a challenge, Dental Care Professionals up and down the country spend countless hours teaching, encouraging and cajoling their patients into extending their cleaning routines to include the all-important interdental sites.

Fig 2. Interdental brushes: a colourful and effective solution for cleaning around appliances.
Fig 2. Interdental brushes: a colourful and effective solution for cleaning around appliances.

Happily for us, the advent of interdental brushes has made this task more achievable for the average patient. From a clinical perspective, flossing is only indicated if the spaces between the teeth are too small for a brush to fit, interdental brushes are an effective and easy option that patients can and will use. If they can use a pen then they can generally use an interdental brush.

Cleaning orthodontic appliances has never been so easy… or colourful for that matter!

Size and availability

Selecting the correct size of brush is crucial to both the effectiveness and durability of the brush. Most makes of interdental brushes come in a range of sizes with many of the companies colour-coding the brushes according to the brush head size. This can be confusing as there is no parity between brands and so a red TePe brush, for example, does not equate to a red in another brand. Practitioners need to ensure that the patient is using the correct sized brush and that they have adequate access to a continued supply of that brush. Brands that are available in professional practice, as well as in general retail, offer the best opportunity for compliance.  Human nature generally guides us all to the easiest choice. Patients do not usually go out of their way to ‘shop’ at the dental practice but if the products they need are available at their local supermarket then they are more likely to replace them when necessary (as opposed to quickly purchasing a pack at the reception desk prior to their follow-up appointment with you!).

Review of brush size should be carried out on a regular basis. As the gingival tissues shrink, the interdental spaces become larger and the brushes need to be correspondingly larger to disrupt the plaque.  

Fig 3: Extended handles aid access for cleaning interdentally at the back of the mouth
Fig 3: Extended handles aid access for cleaning interdentally at the back of the mouth


Discussing recommended cleaning techniques with fellow hygienists, and other Dental Care Professionals over the years, has led this author to believe that there really is no accepted technique adopted universally for interdental brushing. As long as the biofilm is disrupted on a regular basis, growth of pathogenic bacteria will be reduced**** Looking at the various manufacturers’ instructions the advice varies from ‘insert and digitate in between the teeth’ to ‘gently move the brush backwards and forwards, turning on insertion to aid access’. Provided an atraumatic and regular interdental brushing technique is adopted, adequate  plaque control can be achieved. Regular review of cleaning technique is recommended, as once interdental brushing is established the patient can be taught to approach the spaces from the lingual and palatal aspect as well as the buccal and labial approach if appropriate.

Filament texture

Research carried out with 30 Orthodontic Specialists and Special Interest Dentists revealed that criterion for selection of interdental brushes was not just limited to size but that texture of the filaments was of equal importance.  A range of extra soft interdental brushes were trialled with extremely positive results from both practitioners and patients. Over half of the respondents confirmed that the softer filaments were more comfortable to use and three quarters of the practitioners found them to be more effective than their usual brushes. Softer filaments do provide a ‘gentle option’ for interdental cleaning and are particularly suitable for cleaning around orthodontic appliances, implants and crown and bridge work. Patients with exposed and sensitive root surfaces may also find the softer filaments more comfortable. Filament choice should be guided by clinical judgement as well as patient preference.

The specialist dental brush market is a vastly expanding sector of the oral hygiene market. The plethora of brushes available can be overwhelming to the average patient who, let’s face it, just wants the simplest way to maintain a healthy dentition! As oral care professionals we have to be discerning in our recommendation of oral hygiene products to minimise confusion and aid compliance. We need to ensure that we recommend product ranges that offer a large selection of sizes, a choice of textures and are available to the patient from several sources, including the ‘all-powerful’ retail sector. Compliance will always be aided if the recommended choice is the easy choice. 

And the future of plaque removal?

Security and intelligence staff put a great deal of effort into information warfare these days. Why? because interfering with the enemies ability to communicate can be an extremely effective way of weakening and possibly destroying them. In the war against oral bacteria some researchers are considering the same strategy. So, until the researchers can harness the potential for interrupting communications within the biofilm to stop adherence, then we have to stick with good old mechanical removal supplemented by chemotherapeutics where necessary.  Keep them brushing and interdental cleaning!

Now - take the CPD test!

i) T Bergulundh, J Jepson, B Stadinger, IH Terheyden ;  Peri-implantitis and its Prevention. Procedings of the EuroPerio Workshop 2018.

ii) Kornman KS, Newman MG, Moore DJ, Singer RE. The influence of supragingival plaque control on clinical and microbial outcomes following the use of antibiotics for the treatment of periodontitis. J Periodontol 1994; 65: 848-854.

iii) Chapple et al . Primary prevention of periodontitis: managing gingivitis. J Clin Periodontol 2015; 42 Suppl. 16): S71–S76. doi: 10.1111/jcpe.12366.

iv) Assessment of caries prevalence among children below 5 years old  Poornima Prabhu, K. T. S. S. Rajajee,1 K. A. Sudheer,2 and G. Jesudass3.
Int Soc Prev Community Dent. 2014 Jan-Apr; 4(1): 40–43.

v) Kiger RD, Nylund K, Feller RP. A comparison of proximal plaque removal using floss and interdental brushes. J Clin Periodontol 1991; 18 681-684.

vi) Data on file Molar/ Ortho 2009.