Journalartikel

Jahr der Veröffentlichung: 2016

Seiten: 21-28

Zeitschrift: Journal of Dentistry

Bandnummer: 51

ISSN: 0300-5712

eISSN: 1879-176X

DOI Link: https://doi.org/10.1016/j.jdent.2016.05.007

Verlag: Elsevier

Abstract: 

Objectives: 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-fillercontaining 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 degrees 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 airbp 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. (C) 2016 Elsevier Ltd. All rights reserved.

Harvard-Zitierstil: Niem, T., Schmidt, A. and Woestmann, B. (2016) Bonding resin thixotropy and viscosity influence on dentine bond strength, Journal of Dentistry, 51, pp. 21-28. https://doi.org/10.1016/j.jdent.2016.05.007

APA-Zitierstil: Niem, T., Schmidt, A., & Woestmann, B. (2016). Bonding resin thixotropy and viscosity influence on dentine bond strength. Journal of Dentistry. 51, 21-28. https://doi.org/10.1016/j.jdent.2016.05.007