Significance of pulpal pressure during clinical bonding procedures

To determine whether pulpal pressure in vital teeth plays a significant role in dentin bonding procedures.

Half the teeth in three baboons received root canal treatment thus eliminating pulpal pressure. All teeth were then prepared on the buccal surface with a diamond wheel to create flat surfaces into dentin, measuring at least 4 mm in diameter. Dentin bonding systems from two manufacturers were applied. Using a Bencor tensile nozzle freehand, 3.5 mm diameter composite buttons were bonded to the prepared surfaces. The animals were sacrificed 24 hours later, the teeth removed and mounted in specimen rings, using the same Bencor tensile nozzle for proper axial alignment. The composite buttons were tested for shear bond strength in a tensometer.

The results showed no statistically significant difference between the two materials tested, furthermore there was no difference in SBS between materials bonded to vital or non-vital teeth. After completion of the tests, 20 teeth (10 for each dentin bonding system) were prepared according to standard laboratory procedures for a dentin bond strength test using the Bencor Multi-T system. The values obtained were higher, but again there was no statistically significant difference between the two systems.