Effect of light-curing, pressure, oxygen inhibition, and heat on shear bond strength between bis-acryl provisional restoration and bis-acryl repair materials.
OBJECTIVE
This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat.


METHODS
Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at 60℃, 100℃, or 140℃. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (α=.05).


RESULTS
There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at 100℃ and 140℃.


CONCLUSIONS
Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment.
Korea University Ansan Hospital, Prosthodontics, Ansan, Republic of Korea.
Ji-Suk
JS
Shim
Korea University Guro Hospital, Prosthodontics, Seoul, Republic of Korea.
Jeong-Yol
JY
Lee
Korea University Anam Hospital, Prosthodontics, Seoul, Republic of Korea.
Yeon-Jo
YJ
Choi
Korea University Guro Hospital, Prosthodontics, Seoul, Republic of Korea.
Sang-Wan
SW
Shin
Korea University Anam Hospital, Prosthodontics, Seoul, Republic of Korea.
Jae-Jun
JJ
Ryu
Bis-acryl; Heat; Relining; Repair; Shear bond strength