Dental decay (caries), gingivitis, and periodontitis can be regarded as infectious diseases in the wider sense. A combination of numerous etiological factors plays a role in the pathology, but contrary to popular belief, genetic predisposition appears to be of minor importance. The level of oral hygiene appears to be the major cause of the above diseases. Fixed-appliance treatment is very likely to induce plaque, and it is therefore extremely important that the patient’s oral hygiene should be of the highest possible standard. It is therefore advisable for patients to use the services of a professional oral hygienist to achieve the best possible level of oral hygiene.
Plaque is primarily found in the retentive areas around the bracket base, and within a short period of time—sometimes less than a month–it may cause permanent decalcification, which ultimately leads to caries if left unattended.
It is widely known that after fixed appliances have been fitted, a bacteriological shift occurs in the oral cavity toward an increase in anaerobic, cariogenic bacteria. The same also applies to the use of self-ligating brackets, which often have larger undercuts and recesses than the traditional tie-wing brackets and therefore provide greater potential for plaque retention ( Fig. 5.1 ). Deminer-alization around the bracket is a significant risk associated with fixed-appliance treatment in general. It is well known that in patients with poor oral hygiene, caries may develop within weeks of fixed appliances being fitted.9 Although in ideal conditions, remineralization of initial lesions can be achieved, the damage is often irreversible4 , 11 , 12 Remineralization is rarely seen and can only occur if the patient’s oral hygiene is of the highest possible standard. Regular general check-up visits with a dental hygienist or general dental practitioner are often the best way of achieving this. However, once the initial lesions have become established, and even if all the above favorable conditions are subsequently met, the patient may still progress from decalcification to carious lesions.
Symptoms and Etiology of Caries
Caries is a disease of the dental hard tissues, with a high prevalence and incidence in adults. Carious disease is characterized by several phases, involving progression, stagnation, and remission. The more advanced stages of the disease are diagnosed clinically and may range from small initial lesions to open cavities.
Active incipient caries is characterized by an “initial white spot” ( Fig. 5.2a ). This is often without loss of continuity in the dental surface. The surface of the affected area appears matt and is rough on probing. This is diagnostically different from the inactive initial carious lesion, which has the typical appearance of a smooth, shiny surface, often associated with a brown spot ( Fig. 5.2b ). Both active and inactive initial caries can progress further to create irreversible loss of tooth substance.
The development and progression of carious lesions is characterized by a number of very diverse and variable factors. The combination of an increased number of pathogens, the presence of low-molecular-weight carbohydrates, and adequate residence time creates an environment in which tooth decay is likely to occur. In physiological conditions and good oral health, the oral cavity is colonized by a relatively stable flora, in terms of the quality and quantity of bacteria. However, this sensitive balance can easily be disturbed by various factors.
Inappropriate oral hygiene and poor nutrition result in an increase in plaque, with a subsequent increase in pathogens.