[Analysis of etiological factors involved in noncarious cervical lesions]

The etiopathology of noncarious cervical lesions (NCCL) is multifactorial and still not fully understood. Tooth wear is defined as loss of dental hard tissue by a chemical or mechanical process that does not involve bacteria. This form of tooth surface loss includes attrition, abrasion, erosion, and abfraction. Noncarious cervical lesions represent loss of tooth structure at the cementoenamel junction. The purpose of this clinical study of NCCL was to analyze the etiology in relation to age and to identify the most important risk factors associated with cervical lesions, as well as patients and teeth more susceptible to NCCL with a focus on more effective treatment of this condition.

The study group comprised 124 patients with NCCL, aged 15-75 years (mean = 44). A questionnaire was distributed addressing medical history--gastric disorders, dietary habits--consumption of acidic drinks, dental history, oral hygiene practices, and parafunctional habits. Clinical examination of tooth wear was performed on four tooth surfaces after air-drying. The distribution and severity of tooth wear was graded using the tooth wear index (TWI) calculated with a computer programme allowing for tooth characteristic to be determined for each decade of life. Depth of the cervical defect was measured with a periodontal probe. TWI was devised to reveal the extent of tooth surface wear irrespective of the cause. Raw scores were compared with the computer using predetermined threshold values which are set to distinguish between acceptable and unacceptable pathological levels of tooth wear for each decade of life and each tooth surface. Dentition status, oral hygiene, periodontal status, gingival recession, number of teeth and their mobility, oral symptoms of parafunction and relationship to lateral and protrusive tooth contact schemes was assessed and analyzed. Statistical analyses were performed with the Stata Statistical Software: release 5. The risk of NCCL formation was estimated with the logistic regression model. Results were presented as odds ratio, 95% confidence interval, and p probability.

Tooth wear on all surfaces of the tooth, including cervical, was related to age and the ranges were 25-60%. Older patients were more likely to exhibit NCCL. Frequency, localization, and depth of noncarious cervical lesions in a given group of teeth was related to age, although NCCL was more common in premolars (mean = 85.1%). Associations between oral hygiene, consumption of acidic drinks, status of periodontium, number of teeth, their mobility and etiology of wedge-shaped defects were revealed. A relationship between lateral excursive contact of teeth, bruxism, and formation of cervical lesions was established evidencing a correlation between occlusal and cervical pathology.

1. Cervical lesions were most common in premolars. 2. Early detection of dental erosion is important for prevention of serious irreversible damage to dentition. 3. An understanding of the multifactorial nature of tooth wear and risk factors of erosion, abrasion, and ab-fraction is important in the patient's diagnostic protocol and management strategy.