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Effect of bleaching agents on bonding to pulp chamber dentine
Author(s) -
Timpawat S.,
Nipattama C.,
Kijsamanmith K.,
Messer H. H.
Publication year - 2005
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/j.1365-2591.2004.00931.x
Subject(s) - sodium perborate , bond strength , distilled water , hydrogen peroxide , dentistry , universal testing machine , pulp (tooth) , chemistry , sodium hypochlorite , smear layer , nuclear chemistry , ultimate tensile strength , materials science , dentin , adhesive , composite material , medicine , chromatography , organic chemistry , layer (electronics)
Abstract Aim To determine the effect of intracoronal bleaching agents on adhesion of bonding agents to pulp chamber dentine. Methodology Forty extracted human maxillary anterior 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, and group 4: sodium perborate mixed with 35% hydrogen peroxide. Teeth were stored in saline at 37 °C for 7 days. After the bleaching agent 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 with 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. Additional teeth were prepared using the same bleaching procedures to investigate the scanning electron microscopic appearance of the dentine surface. Results 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.