Comparison of marginal microleakage of metal copings cemented with three luting cements

BACKGROUND: To evaluate the marginal microleakage in single metal copings cemented with zinc phosphate, glass ionomer, and resin-modified ionomer. MATERIAL AND METHODS: An experimental in vitro study was carried out. The calculation of the sample was determined using the G*Power software; 15 premolars were considered per group. The teeth were carved considering a preparation with a chamfer-type shoulder with an angulation of 6°. Working models were obtained, where the metallic copings were made. Cementation was carried out with zinc phosphate (Prothoplast), glass ionomer (Ketac-Cem Easymix), and resin-modified ionomer (Relyx™ Luting 2) cements. The samples were immersed in 2% methylene blue solution for 24 hours. The microleakage measurement was carried out with a 40x stereo microscope at four measurement points (vestibular, lingual, mesial, and distal). In order to compare the microleakage values, the ANOVA test was carried out, followed by the Scheffé test. A significance level of 5% was adopted. RESULTS: The zinc phosphate cement showed the highest values of marginal microfiltration (109.28 ± 51.27 µm) followed by the resin-modified ionomer cement (102.63 ± 45.07 µm) and the ionomer of glass (98.64 ± 39.18 µm), although these differences were not statistically significant (p>0.05). CONCLUSIONS: Zinc phosphate, glass ionomer, and resin-modified ionomer cements exhibited similar properties to prevent marginal microfiltration in unitary metal copings. Key words:Cementation, dental leakage, dental restoration failure.