How to prevent tooth decay
17/03/24, 18:00
The science behind tooth decay
Dental caries, commonly referred to as tooth decay, manifests as a gradual process and
progressive disease affecting the dental hard tissues, resulting in the breakdown of tooth
structure and the potential for pain and infection within the oral cavity. Understanding the
mechanisms behind tooth decay is crucial for adopting effective preventative measures, to
stop or reverse the carious process and prevent cavity formation.
Several factors contribute to dental caries, including bacteria, time, fermentable
carbohydrates, and a susceptible tooth surface. In the absence of regular toothbrushing, a
plaque biofilm is allowed to form on the tooth surface—a sticky, colourless film that serves
as a breeding ground for bacteria such as Streptococcus mutans and Lactobacillus species.
Once these bacterial species encounter fermentable carbohydrates and sugars from our
diet, they begin to metabolise them, producing acids as a by-product. These acids contribute to an acidic environment in the mouth. When enamel, the outermost layer of tooth structure, is exposed to an acidic pH below 5.5, its mineral structure weakens, initiating the dissociation of hydroxyapatite crystals. Frequent acid attacks from dietary sugars result in a net mineral loss in teeth, leading to cavity formation, dental pain, and potential infections.
The initial stage of decay involves the demineralisation of enamel. At this point, the damage
can be reversible with good oral hygiene practices and through remineralising agents. Saliva
has the capacity to remineralise initial carious lesions, and fluoride application through
fluoridated toothpaste can also aid in reversing the initial stages of dental caries. However,
if left untreated and allowed to progress, the decay can develop further into the tooth
structure reaching the softer dentine beneath enamel. Dentin decay occurs more rapidly
than enamel and can contribute to increased sensitivity and discomfort.
As the decay advances, it may reach the dental pulp, which is the nerve of the tooth.
Infection of the pulp can trigger severe pain and may necessitate root canal treatment in
attempt to save the tooth. Persistent infections can lead to abscess formation—a pocket of
pus causing swelling, pain, and systemic health issues, should the infection spread
throughout the body.
Tooth decay can be preventing through regular brushing with a fluoride toothpaste. The
consistent disturbance to the plaque biofilm formation through brushing it away will not
allow the caries process to continue, and hence prevent cavity formation. The fluoride
aspect will help to strengthen the enamel and remineralise any mineral loss found in early
lesions; this can stop and even reverse the carious process, thus preventing dental decay
A healthy diet with limited consumption of sugary foods and drinks can significantly reduce
the risk of tooth decay; with less sugars in the oral environment there is a lower rate of
bacterial metabolization to create the acids which contribute to the decay process.
Regular dental check up appointments enable early detection and intervention of any initial
lesions, preventing the progression of decay before reaching an irreversible status.
Tooth decay is a preventable yet prevalent oral health issue. Instigated by the action of oral
bacteria metabolising sugars in the mouth, our natural tooth structure can be destructed
and decayed if the plaque biofilm is not controlled. By understanding the causes and
progression of tooth decay, individuals can adopt proactive measures to maintain good oral
hygiene, preserve enamel, and safeguard their smiles for a lifetime. Regular dental check-
ups and a commitment to a healthy lifestyle play pivotal roles in preventing the onset and
progression of tooth decay.
Written by Isha Parmar
Reference
(Banerjee & Watson, 2015): Banerjee, A. and Watson, T.F. (2015) Pickard’s Guide to
Minimally Invasive Operative Dentistry, King’s College London.