Conduct of an algorithm in quantifying simulated palatal surface tooth erosion

In order to test the ability of an algorithm to quantify simulated palatal erosion, a total of 10 extracted permanent upper central incisors were moun ted in brass blocks. Baseline impressions were recorded using an addition c ured silicone impression material in a metal impression tray. Once set and removed from the teeth, the impressions were coated twice with a high silve r content electroconductive paint, applied using a brush, before being back ed up with die stone to form an electroconductive replica. Each tooth was t hen subject to three treatments: application of phosphoric acid etchant gel for 60 s, application of etchant gel for 120 s and immersion for 3 h in Di et Coca-Cola*. After each one the replication process was repeated. Thereaf ter all replicas were mapped using a computer controlled electrical probe a nd the resultant digital terrain models (DTMS) compared using a surface mat ching and difference detection algorithm (SMADDA). Surface matching was uns uccessful only in one instance. As the duration of the insult increased, so did the proportion of the surface that underwent change to a maximum of 33 .3%. Anatomical site was significantly (P < 0.05) associated with the susce ptibility to erosion. The cingulum periphery appeared most resistant to thi s. The algorithmic approach offers much scope for monitoring dental erosion as acid dissolution of the tooth's surface appears to occur gradually. The cingulum region appears relatively more resistant to this process than oth er tooth sites and thus facilitates the process of surface matching. Furthe r testing is however, required to determine precisely the algorithm's upper tolerance level.