Effect of different application times of 1.3% green tea extract on the bond stability of etch-and-rinse adhesive system to dentin

Efeitos de diferentes tempos de aplicação do extrato de chá verde a 1,3% na estabilidade de união de sistema adesivo convencional à dentina

ABSTRACT

Objective  The study aimed to assess the impact of different application times of 1.3% green tea extract on the bond stability of an etch-and-rinse adhesive system to dentin.

Methods  Thirty third molars had their occlusal enamel removed to expose the dentin surface, which was then subjected to acid etching. The dentin fragments were divided into three groups based on green tea application time: 30 seconds, 60 seconds, and 0 seconds (control group, no treatment). The adhesive system (Adper Single Bond 2, 3M ESPE) was applied to the dentin, followed by the addition of four nanoparticulate composite resin cylinders (Filtek Z350 XT, 3M ESPE) to each sample. After 24 hours, two cylinders from each sample underwent microtensile bond strength testing, and the remaining two were tested after six months of storage in a solution simulating biological fluid. The fracture modes were analyzed under a stereomicroscope, and data were subjected to Fisher’s exact test (α=0.05).

Results  Results showed that after 24 hours, the 30-second Green Tea Group had significantly higher bond strength compared to the control group (p<0.05). However, after six months, the bond strength of the 60-second Green Tea Group was significantly lower compared to the other groups (p<0.05). The Green Tea pre-treatment and storage time did not significantly affect the fracture modes (p>0.05), with most failures classified as mixed.

Conclusion  In conclusion, while pretreatment with 1.3% green tea for 30 seconds increased immediate bond strength, it did not show a difference compared to the control group after six months, indicating limited long-term effectiveness.

Indexing terms
Dentin; Dentistry, operative; Green tea