레이저 照射後 臼齒用 복합레진의 結合力에 關한 硏究 = A Study on the Bond Strength of Posterior Composite Resin after Laser Irradiation

다국어 초록 (Multilingual Abstract)

The purpose of this sutdy was investigating the bond strength between composite resin and enamel surface of the tooth.
The enamels of sound primary molars and permanent premolars were used for experiment. They were extracted for orthodontic therapy or at physiologic exfoliation. They were classified into 10 groups at random ; 1 control group, 4 experimental groups were contained in self-curing resin and light-curing resin each.
Laser impacts on each experimental groups were made at energy density of Q-switched Nd : YAG laser with 3.6J/m^2 and 10.8J/cm^2, Giant pulsed Nd : YAG laser 40J/cm^2 and Normal pulsed Nd : YAG laser with 40J/cm^2.
Then the decalcified patterns of enamel by 36% phosphoric acid were investigated with scanning electron microscope add adhesive shear strength was measured on the each decalcified enamel surface after adhesion of light-curing and self-curing resin.
All the decalcified enamel surfaces were classified into 3 groups and the hardness change after laser irradiation was examined.
The obtained results were as follows.
1. There were not significant difference statistically between the light-curing resin groups in adhesive shear strength of primary molar(P>0.05), but significant increase in bonding force of self-curing resin groups as significant level α=0.05 in Q-switched Nd : YAG laser with 3.6J/cm^2, significant level α=0.01 in Normal pulsed Nd : YAG laser with 40J/cm^2.
2. There were not significant difference statistically between the light-curing resin groups in adhesive shear strength of permanent premolar, but significant increase in bonding force of self-curing resin groups as significant level α=0.05 in Q-switched Nd : YAG laser with 10.8J/cm^2 and Normal pulsed Nd : YAG laser with 40J/cm^2.
3. There were significant increase in bonding force of self-curing resin groups(α=0.01) in contrast to light curing resin groups when adhesive shear strength was examined with primary molar and permanent premolar.
4. In the hardness change after laser irradiation. primary molar was decreased significantly only in irradiation of Normal pulsed Nd : YAG laser as significant level α=0.01(P<0.01). In case of permanent premolar, significant decrease was seen statistically as significant level α=0.05 in Giant pulsed Nd : YAG laser irradiation and significant level α=0.01 in normal pulsed Nd : YAG laser irradiation(P<0.01).