Marginal Ridge Breakdown as a Predictor for Pulpal Involvement in Primary Molars

Background: To date only a few studies have conducted the relationship between marginal ridge breakdown and pulpal involvement. The purpose of this study was to evaluate the extent of marginal ridge breakdown and the chances of pulpal involvement in primary molars.

Methods: Children under the age of 8 years, who had both clinical and radiographic records (n=200) were included. Six examiners evaluated the clinical photographs to determine the extent of marginal ridge breakdown which was grouped as 0-25%, 25-50%, 50-75% and 75-100%. Both clinical photographs and bitewing radiographs were used for determining the relation between marginal ridge breakdown and pulpal involvement. Appropriate statistical tests were employed for data analysis.

Results: When there was any evidence of marginal ridge breakdown, 11% had caries into outer half of enamel, 17% had caries in the inner half of enamel, 5% had caries into the dentino-enamel junction and 56% had caries into inner half of dentine. When the extent of marginal breakdown exceeded 50%, 55% had caries into inner half of dentine. When there was complete marginal ridge breakdown of the marginal ridge, 85% had caries extending into the pulp.

Conclusion: When there was more than 50% of marginal ridge breakdown but less than 100%, 55% had caries extending into pulp. Therefore, breakdown of the marginal ridge can be used as a predictor die pulpal involvement in primary molars.