A microtonsile bond strength of the pulp chamber dentine treated with different bleaching agents

Abstract EN

This study was performed to determine the effect of intracoronal used bleaching agents on adhesion of bonding agents to pulp chamber dentine.

Forty extracted human maxillary central incisors teeth were randomly divided into four groups of 10 teeth each.

Bleaching agents were sealed in pulp chambers for 7 days, as in clinical use.

Group 1(control) : distilled water, group 2 : 35% hydrogen peroxide, group 3 : sodium perborate mixed with water, group 4 : sodium perborate mixed with 35% hydrogen peroxide.

Teeth were stored in saline at 37 C for 7 days.

After the bleaching agents was removed, teeth were leached in water for a further 7 days prior to bonding.

The crown was cut vertically from mesial to distal and the labial pulp chamber dentine was prepared for bonding with Clearfil SE-Bond and filled resin composite (Clearfil AP-X).

The bonded specimens were kept moist at 37 C for 24 h.

microtensile bond strengths were determined using a universal testing machine.

The mean values (±SD) of microtensile bond strength for the experimental groups were : group 1 : 5.29 ±2.21 MPa, group 2 : 5.99 ±1.51 MPa, group 3 : 9.17 ±1.65 MPa, and group 4 : 3.99 ±1.31 MPa.

Dentine treated with sodium perborate in water ( group 3) had significantly higher mean bond strength when compared with the other three groups( p< 0.05, Tukey's test).

Mean bond strength was lowest when dentine was treated with sodium perborate plus hydrogen peroxide (group 4).

Conclusions In terms of subsequent bond strength during restoration, sodium perborate mixed with distilled water appears to be the best intracoronal bleaching agent.