Both are highly antimicrobial but the diacetate salt is particularly effective against Streptococcus mutans (Chart 1). As shown, various types of fluoride are not.

Chart 1

Source: Balanyk T. 1986. Development of a sustained-release antimicrobial dental varnish effective against Streptococcus mutans in vitro. Master’s thesis, University of Toronto.

Prevora contains 100mg/ml of chlorhexidine diacetate or significantly more than the concentration required to kill Streptococcus mutans on the tooth surface. The 0.2mg/ml chlorhexidine rinse and 1mg/ml chlorhexidine gel also contain concentrations well above the minimum bactericidal concentration of S. mutans.

So why not just the rinse or gel to control S. mutans? There are many good reasons:

1. The rinse and gel are not indicated (or approved) for caries prevention in high risk adults – recommending these products for caries prevention constitutes off-label use. Only Prevora has this approved use based on 2 randomized controlled clinical trials.
2. The rinse and gel are subject to patient non-compliance because they are used at home. Studies show that perhaps 40% of patients will take the rinse or gel according to the regimen. This leads to disappointment and wasted effort by the provider and the patient.
3. The rinse and gel cause staining of the teeth. Prevora does not.
4. Prevora builds a schedule of repeat visits for the hygiene team.

So, when considering chlorhexidine for caries prevention, the only choice is Prevora.

Ross Perry

With many more people undergoing elective treatments for aesthetic purposes, it’s absolutely vital that dental professionals go through the necessary procedure to obtain appropriate and valid consent before proceeding with any treatment.

Patients must receive a clear explanation of the proposed treatment, the cost, and any risk and alternative treatments – and then allowed a period of time in which to consider whether they wish to proceed

‘It’s important to remember that obtaining consent is not a one-off event. Dental professionals should be confirming at every appointment during the course of the treatment, that the patient understands the risks and benefits and that they can change their mind at any time. It’s also advisable to have consent protocols which help to ensure consistency across the dental team.’

In a new era when there is more effective preventive care with Prevora, informed consent needs to be provided for many, if not all, restorative procedures. That is because, no longer is dental decay unavoidable or un-preventable, and thereby no longer is restorative services the only approach to managing this disease.

The central issue to obtaining informed consent is effective communication. As noted in other blogs on this website, the medical professions including dentistry do not have a stellar record on speaking to the patient so that all recommended and performed procedures are fully understood. For example, 72% of patients are unable to list medications they take, 58% are unable to recite their own diagnosis, and 47% of what a clinician says is never understood by the patient.

A close relative of mine received a new crown about 18 months ago. She was never informed that this crown would be uncomfortable, would be very expensive, and would last perhaps 7 years before it failed. She was also never advised that recurrent decay led to the crown, and that this underlying disease also needed to be addressed.

So, it is no surprise that patients are now visiting the internet to get more informed before they visit the dentist. And it is no surprise that any consumer awareness campaign for Prevora has met with great interest.

Ross Perry

Chlorhexidine is a strong antimicrobial substance incorporated in oral rinses, oral gels, a tooth coating (Prevora), and a small implantable wafer (Periochip). Two forms of chlorhexidine are normally used: the gluconate salt and the acetate salt. The latter is more bactericidal to Streptococcus mutans, the primary microorganism in caries, but both salts are significantly more effective than fluoride in reducing cariogenic bacteria (Chart 1).

Chart 1

Source: Balanyk T. 1986. Development of a sustained-release antimicrobial dental varnish effective against Streptococcus mutans in vitro. Master’s thesis, University of Toronto

There are some drawbacks to chlorhexidine’s use in the oral cavity. The chemical stains the teeth in reportedly 1 in 10 or so patients, and it also can cause a bitter taste or even stinging of the gums. These side effects can result in poor patient compliance.

Chlorhexidine has “substantivity” or an ability to bind to oral surfaces and prolong its antimicrobial effects. This property is largely attributed to its positive charge being attracted to the negative charge of the tooth or oral mucosa. In the case of Prevora, chlorhexidine acetate has been found at inhibitory concentrations for several weeks during in vitro experiments. This is far longer than reported for the chlorhexidine rinse.

Ross Perry

There is little the dentist can do about either development. But there is a lot to be done about the value proposition of family dental care.

A value proposition is defined by Wikipedia as “a promise of value to be delivered and a belief from the customer of value that will be experienced.” It starts with understanding what the patient wants and expects from his/her professional dental care.

We have been surveying adults in the waiting room of several clinics in the England, to understand what the value proposition is for this type of patient. We have asked these patients to give us their reasons for attending the dental office, and what they hope and expect from their dental visit.

The primary reason for purchasing dental services is health and the associated prevention of disease (Chart 1). Cosmetic treatment is a relatively small motivator.

Chart 1

In terms of expectations, the adult patient re-confirms the primary motivator for purchasing dental care – health (Chart 2). They want to be re-assured their mouths are free of dental decay.

Chart 2

So the central value proposition of family care is better oral health. Contrast that proposition with the recent marketing emphasis of many practitioners on cosmetics (e.g. smile clinics) and implants.

When times are tough and uncertain, the successful business gets closer to its customers. In family dental care, that means more prevention and more promotion of oral health.

Ross Perry

Evidence-based care is clearly difficult to implement because it disrupts traditions and perceptions of both the patient and the provider. It can also affect the business model of medical and dental care. The 6-month recall exam and cleaning, for example, has been a major activity in most family practices.

Prevora is the first evidence-based preventive treatment for adult caries, a very common disease which has a wide variety of preventive regimens with only anecdotal effect, and a standard of restorative care which is a cornerstone tradition of the dental profession.

The acceptance of Prevora is therefore, reliant on education of the patient and the provider, as well as a compelling and obvious proposition – namely, a painless and affordable path to better oral health.

Warren Buffett wanted his PSA test for his own comfort and confidence. When he learns about Prevora from community awareness programs, presumably Mr.Buffett will want the same re-assurance for his oral health.

Ross Perry

Significant factors for health-promoting behaviour for both men and women were: ages 55 – 64, intermediate or higher education, being married, and being employed.

This period of persistently high unemployment is perhaps the biggest factor for health-risk behaviour. For example, more than 8 out of 10 employed Finns followed a comprehensive program of oral care, compared to less than 2 in 10 unemployed.

We found a similar relationship in Prevora’s final randomized controlled clinical trial of 983 community-dwelling adults. Those with lower socio-economic status (namely the uninsured and those on public health dental benefits) had significantly greater dental decay than those who could afford dental insurance (and were employed).

Fortunately, it was amongst the lower socio-economic participants that Prevora’s treatment effect was remarkably significant.

Ross Perry

The study enrolled 231 adults (mean age of 37 to 38 years) who attended a clinic in an American dental school. Most participants were considered high risk for dental decay because of cavities at screening and because of salivary mutans streptococci, lactobacilli and fluoride levels.

The treatment group received a combination of fluoride dentifrice (1,100 ppm NaF), 0.12% chlorhexidine rinse based on bacterial challenge, and 0.05% NaF rinse based on salivary fluoride levels. Testing for bacteria and fluoride levels was conducted every 6 months, and treatment regimens adjusted accordingly.

The control group received no such combination of fluoride and chlorhexidine.

The follow up period was 2 years.

The drop-out rate was significant. About half remained in the study to its conclusion. This level of participation may have affected the ability of the study to report better treatment outcomes.

These were significant observations:

1. Restoring caries in the control did not significantly reduce bacterial challenge nor did it change caries risk status, or caries.
2. By contrast, the combination of fluoride and chlorhexidine according to need, significantly lowered the percentage of subjects at high risk.
3. The caries increment (new caries surfaces) were significantly reduced (24% at p=0.02) when certain appropriate statistical tests were used.
4. Patient compliance to the homecare regimen was uncertain, particularly for the fluoride rinse.

By contrast, in Prevora’s Phase III study of at-risk adults, the treatment effect was much more robust and less reliant on homecare (Chart1).

Chart 1

Preventive effect of various agents for caries in adults (as per controlled studies and p less than 0.05)

Ross Perry

As reported, “Patients and their families approach the whole question from a more personal angle, of course. And, not surprisingly, their estimations of value are quite different from those the cost-watching regulators come up with.”

We have found a similar phenomenon in the willingness to pay for Prevora (which importantly, is only a fraction of the cost of new cancer treatments!). In our studies of 19 dental practices, patients were willing to pay for this new preventive procedure at prices above those set by the practitioner.

Hope for a healthy mouth in the future, and hope to avoid the repeat anxiety of drill and fill are contributors to the patient’s willingness to pay for more preventive care. Another factor is the growing awareness of the recurrent cost of root caries, and the risks to overall health from this chronic disease.

So we see similarities in the emotion around dental decay and cancer – the patients want none of it and will pay for its treatment, often more than the providers ever imagined.

Ross Perry

But patients are not accustomed to asking about cost before visiting their doctor or lab or pharmacy. So there needs to be a lot of education about consumerism in medical care.

I found this story to be remarkable because the cost-consciousness in dentistry is profoundly different. User pay is becoming the name of the game. Patients are looking for lower costs.

So getting patients to be better shoppers of dental services is thereby considered to be easier. Indeed, surveys show that adult dental patients are sensitive to both cost and convenience; in one UK survey, for example, 40% of respondents said they would switch dentists if there were more convenient care.

One issue in dental care is choice. So far, there has been limited choice; one office offers much the same set of services and at the same price as others. Even cosmetic services such as tooth whitening are almost universally offered at a narrow range of prices.

In ongoing surveys of adult patients in the waiting rooms of innovative dental practices in the UK, we have found a remarkably strong preference for services not yet offered by professional dental care. These services pertain to more preventive and predictive care.

Patients have indicated they will gravitate to this kind of care when they know about it, and where it is offered. In this sense, patients will not need to be urged to consume their dental services more carefully. From the response to these surveys, they will enthusiastically choose what they prefer – more prevention.

Ross Perry

The phenomenon of bacteremia (microorganisms entering the blood stream) has been known for many years. Indeed, the role of S. gordonii in bacteremia is also well documented. Perhaps what is new here is the ability of these oral bacteria to initiate the clotting cascade.

But so what? What do you say to your patients who reads these kinds of articles in the Daily Mail?

It seems the patient is left with that ubiquitous recommendation to brush his/her teeth more regularly.

However, the 2009 Adult Dental Health Survey in the UK showed that 97% of adults already do brush their teeth regularly. What else might be done and should it be done?

The second question is easier to answer. The role of dental plaque-based bacteria in heart health is becoming clearer. Most of the research is focused on bacteria associated with periodontal disease but some important work has documented the prominence of Streptococcus mutans, the bacteria initiating dental caries, in the plaque of diseased arteries.¹

But what about controlling S. gordonii? Brushing will likely have little long-term effect; studies show that brushing cannot clear the mouth of these kinds of bacteria. Indeed, the majority remain in the cracks and crevices after brushing and return to original levels quickly.² To reduce the levels of these bacteria, more drastic measures are required: a professional prophylaxis followed with antimicrobial therapy such as Prevora.

I would caution, however, that there are no studies linking this kind of treatment to significant reductions in S. gordonii and in turn, a reduction in heart disease. Such studies would take many years and many millions of dollars to conduct and hence, will likely never happen.

Ross Perry