Fluoride release and flexural strength of four ion-releasing restorative materials: An in vitro comparative study.

BACKGROUND: This study aimed to determine the fluoride release and flexural strength of four ion-releasing restorative materials. MATERIAL AND METHODS: A total of 80 samples of four different materials were prepared in standardized molds: Ketac Universal, Beautifil II, Cention N, and Equia Forte Fil. The fluoride release was quantified at 1, 3, 7, 14, and 28 days post-immersion using an ion-selective electrode. The flexural strength was measured with a universal testing machine after 7 days of immersion in deionized water. A one-factor intergroup ANOVA with Welch's robust variance and Games-Howell's post hoc was employed. To compare related measures, a Friedman test with Bonferroni's adjusted post hoc was employed. The p-value was set at 0.05. RESULTS: At 7 days, significant differences were observed in the flexural strength of the four ion-releasing restorative materials (p<0.001). The flexural strength values from highest to lowest were as follows: Cention N (97.10 ± 4.99 MPa), Beautifil (82.77 ± 5.30 MPa), Equia Forte Fil (31.38 ± 7.68 MPa), and Ketac Universal (19.23 ± 2.94 MPa). In addition, at 3 and 7 days, the highest amount of fluoride released was observed for Cention N compared to the other ion-releasing restorative materials (p<0.05). Conversely, Beautifil II released the lowest amount of fluoride at 3, 7, 14, and 28 days (p<0.05) compared to the other ion-releasing restorative materials. CONCLUSIONS: The immersion of all ion-releasing restorative materials in deionized water for seven days resulted in significant differences in flexural strength. Cention N had the highest value, while Ketac Universal had the lowest. All ion-releasing restorative materials released fluoride at all test times, with Ketac Universal releasing the most at 1, 14, and 28 days, and Cention N releasing it at 3 and 7 days. Beautifil II showed the lowest fluoride release at all evaluated times, exhibiting a nearly constant release over time compared to the other materials. Key words:Fluoride release, flexural strength, glass ionomer.