Effectiveness of Various Toothpastes to Occlude Dentin Tubules

Method: Twenty extracted human molars were divided into fife groups of four teeth each. They were cut into two halves of which one served as control the other as experimental halve. A 3x3mm plane window was prepared on the root surfaces to open dentin tubules. Prior to the experiments the windows were treated with Lemon Juice (Hitchcock, pH 2.45) for 30 seconds to demineralize the surface. The experimental halves were treated with Sensodyne Rapid^®, Signal Anti-Age^®, ELMEX Sensitive Professional^®, Bio Repair^®, ELMEX^® tooth paste by brushing the windows with the tooth paste for 30 Seconds. Then they were rinsed with water for another 30 seconds. This procedure was repeated 28 times. The control halves remained in remineralization solution. Then the teeth were critical point dried and the surface was investigated with scanning electron microscopy (SEM). Afterwards the tooth halves were broken mechanically into further halves and the fractured planes were again investigated using SEM.

Result: SEM of the surfaces of all control teeth showed open dentin tubules. In the experimental halves granular surface covering or clusters of granules with varying size which occluded all tubules could be seen in all specimens. The fractured planes demonstrated occasionally penetration into single dentin tubules between 1 – 4µm depth. Most of the dentin tubules were not penetrated. In one tooth paste no penetration could be seen at all.

Conclusion: This experimental study showed no obvious difference between the various toothpastes. Regular penetration into dentin tubules could not be observed. However, further investigations with methods which allow quantification of dentin tubule penetration are needed.