Comparison of Different Standardised Bond Strength Tests and the Influence of Glycine Powder Treatment in Composite Resin Repairs

Aim: The repair of restorations is an eligible method to extend the survival rates of intraoral restorations. There is a consensus that the old surface has to be removed before repair by the use of a sandblaster or rotating instruments. This study aimed to investigate whether a glycine powder can be used successfully in composite repair by measurement of shear and tensile bond strength according to dental standards. Methodology: The influence of mechanical preparation by no powder, 25 µm glycine powder or 50 µm aluminium-oxide powder and chemical conditioning by the use of bonding, phosphoric acid and bonding or bonding, phosphoric acid and a silane on the repair bond strength of an artificially aged nano-hybrid composite was tested according to the guidelines of DIN 13990 (2017), ISO 29022 (2013) and ISO/TS 11405 (2015). The fracture modes were evaluated by adhesive, cohesive or mixed failures. Results: There was no significant difference in the performance of the different mechanical and chemical treatments. The shear bond test according to DIN 13990 (2017) produces higher repair bond strengths (26.0±8.9 MPa) than the test described in ISO 29022 (17.9±6.3 MPa). The tensile bond strength according to ISO/TS 11405 (6.9±1.8 MPa) was the lowest. Most adhesive failures occurred with the shear test according to ISO 29022 (41%), followed by DIN 13990 (18%) and the tensile test (4%). Conclusion: For evaluating the bond strength of composites the test described in ISO 29022 is recommended, because it produces the highest percentage of adhesive failures. Nano-hybrid-composites are robust to different repair protocols. How to cite this article: Herrmann GP, Reimann S, Daratsianos N, Weber A, Keilig L, Nadal J, Bourauel C. Comparison of different standardized bond strength tests and the influence of glycine powder treatment in composite resin repairs. Int Dent Res 2020;10(1):36-43. https://doi.org/10.5577/intdentres.2020.vol10.no2.2 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.