Giorgia Carpegna - Ilaria Quartarone - Vittorio Di Fortunato
DEFINITION
Dental erosion is a multifactorial condition, is the irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin. Erosion is found initially in the enamel and, if unchecked, may proceed to the underlying dentin.
Bulimia nervosa is an eating desorder characterized by recurrent binge eating, followed by compensatory behaviors.
The most common form is defensive vomiting, sometimes called purging; fasting, the use of laxatives, enemas, diuretics, and over exercising are also common.
EPIDEMIOLOGY
Dental erosion is the most common chronic disease of children ages 5–17, although it is only relatively recently that it has been recognised as a dental health problem.
Bulimia, instead, has been studied for the first time in 1979, even if it was already known in the past.
The incidence of this disease during the years has been expanding, nowadays it affects 2% feminine population's.
The most affected age is about 18 years old, even if the disease appears also at 12 years old.
SYMPTOMS
There are many signs of dental erosion, including changes in appearance and sensitivity.
One of the physical changes can be the color of teeth.
There are two different colors teeth may turn if dental erosion is occurring:
- The first being a change of color that usually happens on the cutting edge of the central incisors. This causes the cutting edge of the tooth to become transparent.
- A second sign is if the tooth has a yellowish tint. This occurs because the white enamel has eroded away to reveal the yellowish dentin.
A change in shape of the teeth is also a sign of dental erosion.
Teeth will begin to appear with a broad rounded concavity, and the gaps between teeth will become larger.
There can be evidence of wear on surfaces of teeth not expected to be in contact with one another.
DIAGNOSIS
There is some evidence that dental erosion is growing steadily. To prevent further progression, it is important to detect this condition as early as possible.
The clinical examination has to be done systematically, and a comprehensive case history should be undertaken such that all risk factors will be revealed.
PATHOGENESIS
The interplay of chemical, biological and behavioural factors is crucial and helps explain why some individuals exhibit more erosion than others. The erosive potential of erosive agents like acidic drinks or foodstuffs depends on chemical factors like pH, titratable acidity, mineral content, clearance on tooth surface and on its calcium-chelation properties.
Biological factors such as saliva, acquired pellicle, tooth structure and positioning in relation to soft tissues and tongue are related to the pathogenesis of dental erosion. Furthermore, behavioural factors like eating and drinking habits, decrease of salivary flow, excessive oral hygiene and, on the other side, an unhealthy lifestyle like chronic alcoholism or eating desorder, are predisposing factors for dental erosion.
According to this we can say that conditions such as anorexia and bulimia nervosa cause palatal dental erosion.
Some studies reveal high levels of α-amylase in patient with bulimia:
[Alpha-amylase isoenzymes in serum and saliva of patients with anorexia and bulimia nervosa] 1991
or make a relation between α-amylase, isoamylase and the shame of eating, usual in bulimic patient.
[Serum salivary isoamylase levels in patients with anorexia nervosa, bulimia or bulimia nervosa] 1986
furthermore it's demonstrate, with the results of screening, that Bacillus sp. strains isolated from different natural substrates, strain BKL20 was identified as a producer of a thermostable alkaline alpha-amylase.
[Production and properties of α-amylase from Bacillus sp. BKL20] 2010
So, we can suppose that α-amylase, acting in glucose metabolism, may increase the lactic acid in the mouth, increasing the dissolution of theeth's enemel.
COMPLICATION
The exact causes of hyperamylasemia detected in bulimia nervosa are unknown but it is presumed to be due either to repeated binging or to vomiting.
Studies suggests that it is the vomiting rather than the binge behavior that increases amylase in bulimic patients. This increased amylase probably comes from the salivary gland.
Hyperamylasemia in bulimic patient it also related to salivary gland enlargement. Both frequency and type of vomiting seem to be relevant to the extent of salivary gland enlargement.
Complications are:
- Chronic gastric reflux after eating
- Dehydration and hypokalemia caused by frequent vomiting
- Enlarged glands in the neck, under the jaw line
THERAPY
Dentists have to know the clinical appearance and possible signs of progression of erosive lesions and their causes such that adequate preventive and, if necessary, therapeutic measures can be initiated, like conservative or prosthetic treatments.
Dentists and doctors have also a very important role in further prevention of complication of this disease, they have to suggest a correct lifestyle and diet.
