Protective capacities of dentine bonding agents and fluoride against erosion

Objective: The aim of this study was to compare the protective effect of fluoride to that of a dentine bonding agent on dentine when exposed to an erosive wear regime. Method: 60 teeth were sectioned vertically to expose a large dentine area, avoiding the pulp. 2mm diameter metal discs were cemented onto the dentine and standardised impressions taken of the teeth at the start of the wear regime. The teeth were divided into 4 equal groups; group A was coated with Seal & Protect; group B was protected with fluoride; group C and D were not protected. Each sample was randomly placed into one of the four baths in the reciprocating wear machine. Every 100 cycles A, B and C were immersed in 0.3% citric acid for 5mins. Group B were immersed in fluoride solution for a further 5mins. Standardised impressions were taken at 0, 100, 500, 1000, 2500 and 5000 cycles. All the impressions were scanned with a non-contacting laser profilometer and Data acquisition and analysis were undertaken. Mean step-height measurements from the levelled disc surface to selected areas on the tooth were made. Results: A total of 360 Scans were recorded using the profilometer. At 5000 cycles the median step height for Group A was 0.24mm (confidence interval -0.004 to 0.882mm), interquartile range (iqr) 0.804. Group B had a median value of 0.531mm (CI 0.137 to 1.123), iqr was 0.494. Group C had a median value 0.924mm (CI 0.538 to 2.587) and iqr of 1.295. Group D had a median value 0.5mm (CI 0.114 to 1.075) and iqr of 0.881. There was no significant difference between the groups, p=0.263 using the Kruskal-Wallis test. Conclusion: there was no protective effect of fluoride or dentine bonding in this wear regime.