Evaluation and Comparison of Micro Shear of 5th, 7th and 8th Generation Bonding Agents in Dentin (In Vitro Study)

Introduction: Today various bonding systems are introduced in the market which increase the quality of restoration and durability. The purpose of this study was to compare the shear strength of dentin in three different generations of bonding materials in the market. Methods and Materials: In this study, 60 healthy premolars tooth that were extracted for orthodontic reasons were disinfected and exposed of their dentin with a diamond bur. 3 M Z100 (USA, ESPE) composite were used. Three different generations of bonding materials were used. The 8th Generation (group A) Dentin Bonding Agents was (USA, Scotchbond Universal, 3M ESPE) and 7th generation (group B) was (USA, Adper Easy one, 3M ESPE) and finally 5th generation (group c) was (Germany, Single Bond 2, 3M ESPE) which apply to the dentin surface according to the manufacture instructions. The specimens were thermocycled 1000 times. The shear bond strength was evaluated at a universal testing machine by speed of 0.5 m / min. Results: The mean shear bond strength in Scotchbond Universal group was 15.8 ± 6.08 MPa and in Adper Easy one was 11.24 ± 3.75 MPa and in Single Bond 2 group was 15.24 ± 4.6 MPa.). The mean shear bond strength of group A was significantly different from that of group B (P <0.05). The mean shear bond strength of group A was not significantly different from that of group C (P> 0.05). The mean shear bond strength of group B was not significantly different from that of group C shear bond strength. (P> 0.05). Conclusion: The present study showed that eight-generation bonding systems (Scotchbond Universal, USA, 3M ESPE) has the same shear bond strength as single bond 2 generation has. Also, the shear bond strength of Seventh-generation Adper Easy One is less than the fifth-generation (AdperSingle Bond 2), although this difference was not significant. On the other hand, this generation of bonding is user friendlier due to its ease of use and lower clinical time for use in pediatric dentistry, where isolation and collaboration is a major challenge.