Bonding resin thixotropy and viscosity influence on dentine bond strength

详细信息    查看全文

• 作者：Thomas Niem ; ^{thomas.niem@dentist.med.uni-giessen.de" class="auth_mail" title="E-mail the corresponding author} ; Alexander Schmidt ^{alexander.schmidt@dentist.med.uni-giessen.de" class="auth_mail" title="E-mail the corresponding author} ; Bernd Wö ; stmann ^{bernd.woestmann@dentist.med.uni-giessen.de" class="auth_mail" title="E-mail the corresponding author}
• 关键词：One-bottle self-etch adhesive ; Air-blowing pressure ; Resin tag ; Bonding resin layer ; Blister ; Phase separation
• 刊名：Journal of Dentistry
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：51
• 期：Complete
• 页码：21-28
• 全文大小：2127 K

文摘

To investigate the influence of bonding resin thixotropy and viscosity on dentine tubule penetration, blister formation and consequently on dentine bond strength as a function of air-blowing pressure (air-bp) intensity.

Methods

Two HEMA-free, acetone-based, one-bottle self-etch adhesives with similar composition except disparate silica filler contents and different bonding resin viscosities were investigated. The high-filler-containing adhesive (G-Bond) featured a lower viscous bonding resin with inherent thixotropic resin (TR) properties compared to the low-filler-containing adhesive (iBond) exhibiting a higher viscous bonding resin with non-thixotropic resin (NTR) properties. Shear bond strength tests for each adhesive with low (1.5 bar; 0.15 MPa; n = 16) and high (3.0 bar; 0.30 MPa; n = 16) air-bp application were performed after specimen storage in distilled water (24 h; 37.0 ± 1.0 °C). Results were analysed using a Student’s t-test to identify statistically significant differences (p < 0.05). Fracture surfaces of TR adhesive specimens were morphologically characterised by SEM.

Results

Statistically significant bond strength differences were obtained for the thixotropic resin adhesive (high-pressure: 24.6 MPa, low-pressure: 9.6 MPa). While high air-bp specimens provided SEM images revealing resin-plugged dentine tubules, resin tags and only marginally blister structures, low air-bp left copious droplets and open dentine tubules. In contrast, the non-thixotropic resin adhesive showed no significant bond strength differences (high-pressure: 9.3 MPa, low-pressure: 7.6 MPa).

Conclusions

A pressure-dependent distinct influence of bonding resin thixotropy and viscosity on dentine bond strength has been demonstrated. Stronger adhesion with high air-bp application is explained by improved resin fluidity and facilitated resin penetration into dentine tubules.

Clinical significance

Filler particles used in adhesive systems may induce thixotropic effects in bonding resin layers, accounting for improved free-flowing resin properties. In combination with high air-bp this effect allows an easy plugging of dentine tubules and elimination of blister structures, both resulting in superior dentine bond strength.