Fluoride has been proven to reduce significantly the prevalence of dental caries in the majority of the population.
There are many products used by the dental professional for fluoride therapy, including high fluoride varnishes, gels, rinses and foams. Fluoride has also been incorporated into dental material like silicate restorative materials, glass ionomer cements, composite and amalgam (Ferjskov O, Kidd F, 2003). Fluoride is versatile and thus also used systemically, through fluoridated water, milk, salt and tablets (not many products can deliver such important benefits in such a flexible manner). Many oral hygiene products are fluoridated, such as toothpaste, rinses, toothpicks and floss.
Topical fluoride application
After working in one practice where children were routinely given fluoride gel applications after prophylaxis, I subsequently realised that this is not a standard practice. I often wonder why this was not the norm, as the benefits of fluoride have been well established and generally agreed upon by the dental profession as being useful. In keeping with the current practice of evidence-based dentistry, I reviewed some of the literature and reviews.
Fluoride toothpaste is credited as the most successful fluoride delivery system to have been developed. Most of the population brush their teeth; it is a cultural norm in many societies. Consequently, this is a key element in any caries preventive programme. However, a considerable number of European children brush their teeth only once a day or less and so do not obtain the full benefit from fluoride use, which should be twice-daily or more, if needed (Hausen H, 2004).
Caries prevention programmes also need to be multi-faceted. One public health measure could be to provide free fluoride toothpaste and encourage twice-a-day brushing. Lifestyle changes, however, can be difficult as many people are unwilling to change their normal behavioural mode.
Previously, topical fluoride applications were done in a series to coincide with the eruption pattern of permanent teeth. This was at three, seven, 10 and 13 years, where four applications would be provided at approximately one-week intervals. However, this interval was increased to three and six months, and later six to 12 months. There is little evidence to support the increased intervals and this was done for no reason other than it was convenient to the dentist normal recall system (Harris N, Garcia-Gody F, 1999).
One systematic review (Marinho VC, Higgis JP, Logan S, 2004a) examined one topical fluoride against another for preventing dental caries in children and adolescents.
The objective was to access the comparative effectiveness of toothpaste, mouthwash, gel and varnishes. The conclusion was that fluoride toothpaste, in comparison with rinses and gels, appears to have a similar degree of effectiveness for preventing dental caries.
With fluoride being available from multiple sources and with lower caries prevalence, questions have been raised as to whether topically applied fluoride is still effective in reducing caries – this extends as far as questioning the need for selective professional fluoride applications.
Additionally, the people that are more likely to benefit from individual fluoride application may not visit the dentist regularly, particularly in the least advantaged areas of the population. Fluoride from any one source is likely to be diluted because today people are exposed to fluoride from different sources. Nevertheless, the persistence of this debate suggests that further studies are needed to determine what form of application is most effective, including the safety, acceptance and ease of application.
Other reviews (Marinho VC, Higgis JP, Logan S, 2004b; Marinho VC, Higgis JP, Logan S, 2003a; Marinho VC, Higgis JP, Logan S, 2003b) compare the use of topical fluoride with a single topical fluoride application. The evidence supports the use of topical fluorides; mouthrinses, gels or varnishes, used in addition to toothpaste, achieved a modest reduction in caries when compared to toothpaste alone. However, these benefits were described as not great.
In addition, the review of topical fluoride for preventing dental caries in children and adolescents established the benefits through a sizeable body of evidence from randomised controlled trails.
Evidence-based clinical recommendations influence clinical practice guidelines. However, these recommendations are not a standard of care and need to be balanced with the practitioner’s professional judgement and the individual patient’s preference (Richards D, 2006).
Those who may benefit include:
• Children with newly erupted teeth, within 12 months of eruption, as close to eruption as possible. The benefits of fluoride are greater on newly erupted teeth (Ferjskov O, Kidd F, 2003; Hellwig H, Lennon AM, 2004). Nevertheless, we should bear in mind that it is possible to introduce caries actively into previously healthy dentition at any age
• High risk individuals with increased caries incidence
• Older adults with xerostomia and exposed root surfaces.
A public health perspective
It would seem that the best approach would be to examine the specific need of the patients and develop a tailor-made treatment programme.
There may be a place for the application of topical gels for high-risk susceptible individuals, who are most likely to benefit from it.
However, it can be problematic, from a public health perspective, when attempting to distinguish high-risk individuals who may or may not develop caries in the future (Hausen H, 2004).
The cost of screening high-risk individuals may also be prohibitive. A more favourable and less expensive approach would be the directed population approach, targeting high-risk groups rather than individuals.
There are benefits to be gained from public health programmes, which achieve more when implemented in conjunction with proper oral hygiene instructions. It is evident that there is no single fluoride programme that could be used universally. A decision on the appropriate programme would need to be made after considering:
• Caries prevalence
• Oral hygiene status
• Access to dental services
• Dietary habits
• Socio-economic status, including education, current water fluoridation levels and other fluoride exposures (Ferjskov O, Kidd F, 2003; Ten Cate JM, 2004).
High-risk patients can benefit from behaviour change, with the objective of increasing compliance with simple caries prevention methods like twice-daily brushing. Topical fluoride applications may continue to play a role in caries preventive programmes. The dental team would need to consider the available evidence supporting its use and the patient’s preference, while utilising their professional judgement to determine whether the patient would benefit from its use.
Ferjskov O, Kidd F (2003) Dental caries: the disease and its clinical management. Oxford: Blackwell Publishing Limited
Harris N, Garcia-Gody F (1999) Primary preventive dentistry. Connecticut: Appleton and Topical Lange
Hausen H (2004) How to improve the effectiveness of caries-prevention programmes based on fluoride. Caries Research 38: 263-267
Hellwig H, Lennon AM (2004) Systemic versus topical fluoride. Caries Research 38: 258-262
Marinho VC, Higgis JP, Logan S, Sheiham A (2003a) Fluoride mouthrinses for preventing dental caries in children and adolescents. Cochrane Database of Systemic Reviews (3): CD002284
Marinho VC, Higgis JP, Logan S (2003b) Topical fluoride (toothpastes, mouthrinses, gel or varnishes) for preventing dental caries in children and adolescents. Cochrane Database of Systemic Reviews (4): CD002782
Marinho VC, Higgis JP, Logan S (2004a) One topical fluoride (toothpastes, mouth-rinses, gel or varnishes) versus another for preventing dental caries in children and adolescents. Cochrane Database of Systemic Reviews (1): CD002780
Marinho VC, Higgis JP, Logan S (2004b) Combination of topical fluorides (toothpastes, mouthrinses, gel, varnishes) versus single topical fluoride for preventing dental disease in children and adolescents. Cochrane Database of Systemic Reviews (1): CD002781
Richards D (2006) Topical fluoride guidance. Evidence-Based Dentistry 7(3): 62-64
Ten Cate JM (2004) Fluoride in caries prevention and control: empiricism or science. Caries Research 38: 254-257