Abstract:
The purpose of this in vitro study was to investigate the effect
of 1% NaOCl (15 min) and MTAD on dentine shear bond strength,
when using the Scotchbond XT(3M ESPE) adhesive system.
Thirty extracted, human, third molar teeth were embedded
into metal rings with self-curing acrylic resin. The teeth were
ground wet using 600-grit silicone-carbide paper to expose
superficial dentine. The samples were randomly divided into 2
groups (n=15). In group 1 (SB) the dentine surfaces were treated
according to the manufacturer’s instructions (etched with 37%
phosphoric acid before application of the bonding resin). In group
2 (MTAD) the dentine surfaces were treated by rinsing it with 1%
sodium hypochlorite for 15 minutes followed by the application
of a freshly prepared solution of MTAD, left undisturbed for 5
minutes. Thereafter the solution was rinsed off with water, airdried,
leaving the treated surface visibly moist. Following the
application of the adhesive resin, composite resin were condensed
into an Ultradent mould and then light-cured for 40 seconds. The
bonded specimens were stored in 37 oC water for 24 hours. The
shear test was performed in a Zwick testing machine. The mean
values were analyzed using the Student- t test. The results were
as follows: SB= 15.4 ± 3.4 MPa and MTAD=21.8 ± 3.6 MPa. There
was a statistically significant difference in dentine bond strength
between the two groups (p<0.05). Conditioning of the dentine
with MTAD significantly increased the dentine bond strength of
Scotchbond XT to dentine.
