Use of glass-ionomers for bracket bonding--an ex vivo study evaluating a testing device for in vivo purposes.

Seven glass-ionomer cements were tested and compared with a composite resin in order to find the glass-ionomer cement with the highest bond strength to enamel with normal anatomy and composition (not ground). Five types of surface treatment were used. The results show that Aqua Cem and Ketac Cem, both water-hardening, present the highest bond strength, followed by the conventional glass-ionomer cement Fuji IIF. Surface treatment according to the manufacturers' instructions and surface treatment with polyacrylic acid were found to give rise to the highest bond strength for all of the seven cements. However, none of the glass-ionomer cements reached the values for the composite resin Concise. The testing instrument designed for ex vivo purposes measured with high precision and accuracy and with a low methodological error.