How we’ll look back and laugh at our dread of the drill. If tooth decay were discovered today, nobody would think of such crude ways of getting rid of it — boring it out only when it starts hurting and sealing the hole with fillings large enough to glint in the sun. The world’s leading oral scientists believe that we’re well on the way to consigning drill-and-fill to history. At the International Association of Dental Research annual conference in Baltimore in the US this week, they reported on the growing evidence that a new “minimally invasive” approach to oral health care is best — aiming for the smallest possible filling or, best of all, none at all.
This gentle revolution builds on a simple understanding of oral chemistry. Tooth decay is an infectious disease, caused largely by bacteria which thrive on too much sugar in the diet. If you don’t clean away those bacteria, and if you don’t have plenty of saliva washing around your mouth to neutralise the acids that they produce, they eat away at the surface of teeth, causing essential minerals to leach out. Eventually, tooth tissue is destroyed causing soft decayed areas, known by dentists as caries.
Minimally invasive dentistry uses state-of-the-art technology to detect the first signs of mineral loss in teeth; much earlier than conventional techniques. It then floods the vulnerable spots with healthy minerals, including fluoride, calcium, phosphorus and strontium. If used regularly, such new screening techniques will be able to provide a wake-up call about oral hygiene, and prompt the use of new products which head off the need for fillings.
With up to one in five children showing visible signs of decay in their teeth, there’s plenty of scope for minimally-invasive dentistry in the UK. These are some of the innovations being hailed at this week’s meeting.
Qualitative-induced light fluorescence is an early warning system for dental caries, which could prevent hundreds of thousands of fillings if widely used. It exploits the fact that fluorescent light turns healthy teeth bright green while even slightly demineralised areas become black. Susan Higham, the Professor of Oral Biology at Liverpool Dental Hospital, is supervising trials of this screening tool that picks up decay long before it turns black and nasty. “The problem with dental caries is that there is nothing visibly wrong for months after the infection has taken hold,” she says. “At most there’s a white spot on the tooth.”
Versions for use in dental surgeries, and a smaller toothbrush-sized one for home use, have been developed. According to Higham, there is a substantial bank of evidence show- ing the benefits. Its makers are hopeful that it will be available soon on the NHS.
GC Tooth Mousse is a mineral-rich paste which became vailable to UK dentists last November. It is billed as “the first conditioner for teeth”, halting demineralisation, triggering remineralisation, boosting saliva flow and even reducing sensitivity. “By the time there’s a cavity, it’s too late to remineralise a tooth,” says Dr Harris Sidelsky, a Harley Street dental surgeon and an enthusiast of minimally-invasive techniques. “But this paste saturates the teeth with bioactive calcium and phosphate and helps to knock out bacteria.”
It’s available from dentists at about £15 for a 40g tube.
Saliva-Check is a simple test of saliva levels. Lack of saliva — the result of stress, too little water, too much alcohol or coffee, or some prescription drugs — can encourage tooth decay because the minerals in saliva neutralise bacterial acids. This was confirmed at the Baltimore conference by a Boston University study of 148 patients over 15 years, indicating that low salivary flow is “highly predictive of the development of caries”. The results of a Saliva-Check test might prompt lifestyle changes. It’s available through some dentists, for about £2.50.
Glass ionomer is a dental filler that adheres to the tooth chemically instead of being glued or fitted into a cavity. Invented 30 years ago by British Civil Service scientists, it has been rediscovered. Early studies indicated that it was more likely to fall out than conventional amalgam or composite fillings, but a newer and stronger version is being hailed as the filler of choice in MI dentistry.
Dr Graham Mount, of Adelaide University, Australia, told the conference that studies show that the glass ionomer “strengthens the bond between the tooth and the filler, thereby increasing the resistance of the underlying dentine (inner tooth tissue) against further acid challenges”. He said that it allowed healthy minerals to permeate deep into the dentine.
It’s available on request from some dentists; prices may vary.
Photo-activated disinfection is a non-invasive treatment of deep caries available only in a handful of UK practices. A disinfectant gel is applied on top of the decay, allowed to penetrate and then activated by a laser so that all bacteria are killed. It is then sealed with a glass ionomer filling. The start-up costs for the disinfection are high, since the technique requires a medical-grade laser. Dr Myles Dakin, a Cambridgeshire dentist, says: “The technology allows the tooth to heal itself, eliminating the need for drilling when decay is caught early.”
Atraumatic restorative treatment (ART) removes the need for drilling because it requires the dentist to use a set of miniature hand-held spoons to scoop out dentine softened by decay. The cavity is then sealed with glass ionomer and a layer of Tooth Mousse. The technique was invented by a World Health Organisation scientist for use in countries with limited access to dental equipment. Research indicates that it works; a study of 90 Hong Kong residents, reported in Baltimore, showed that ART fillings work as well a year later as conventional ones.
Long wait in the tooth
With NHS dentists still paid according to how many teeth they treat, and a new system of paying them per patient delayed until next year at the earliest, does minimally invasive dentistry stand a chance of being available on the NHS in the foreseeable future? “We need a paradigm shift, but it could happen,” says Dr Ian McIntyre, who as the director of dental services at South Warwickshire primary care trust is supervising a pilot project to make prevention a priority in dentistry.
McIntyre, a former president of the British Dental Association, says: “Our pilot project pays dentists simply to achieve dental fitness in 70 per cent of patients and early results show payments for fillings in the first year dropped by a dramatic 35 per cent.”
Some private dentists are sceptical about getting good preventive work on the NHS. Dr Myles Dakin, a Cambridgeshire dentist, says: “The minimally invasive philosophy means doing work that lasts. The NHS won’t pay enough to get top-class work done.”
