Objectives:
The aim of this study was to determine whether patients with purging-type bulimia and/or non-bulimic patients, treated with serotonin reuptake inhibitor SI-5-HT (fluoxetine), have dental erosion and changes in selected buffer components of parotid saliva (bicarbonates, phosphates, urea), compared with the healthy population.

Methods:
A controlled clinical trial was designed for three, age-matched, female groups of 94 patients: 1) bulimic patients treated with fluoxetine 40mg/day (n = 25), 2) non-bulimic patients diagnosed with bipolar affective disorder, treated with fluoxetine 20mg/day (n = 25), and 3) healthy controls (n = 44). Parotid saliva was collected from the subjects by means of Lashley cup at rest and stimulated chemically with a 3% citric acid solution. In clinical examination the dental erosion was determined as non-carious tooth substance loss using the Tooth Wear Index (TWI). The concentrations of inorganic phosphates, bicarbonate, urea and pH in saliva were measured.

Results:
In the bulimic subjects higher TWI (24%) and lower levels of pH, bicarbonates and phosphates compared with controls were observed. There were no significant differences in urea concentration.

Conclusions:
Erosive-abrasive tooth surface loss seems to be a significant diagnostic tool of bulimia nervosa. The presence of pathological changes in teeth structure indicates the loss of protective properties of saliva, which is proved by pH value and concentration of buffer ions. It is advisable to monitor salivary parameters, such as salivary flow rate, pH and the concentration of buffer ions in long-term treatment with SI-5-HT drugs in case of patients with purging-type bulimia. There is also a need for regular dental check-ups of the oral cavity tissues.