Comparative Evaluation of Bond Strength and Microleakage of Three Ion-Releasing Restorative Materials at Various pH Levels

Abstract

The aim of this study was a comparison of the micro-tensile bond strength (μTBS) to dentin and microleakage of in vitro class V restorations of three different ion-releasing restorative materials under various pH conditions: giomer, a resin-modified glass ionomer (RMGI), and a new alkasite material. A μTBS test was performed using a universal testing machine, immediately and after storage at different pH (4, 7, and 10) buffer solutions (n = 15) over 24 h, and the failure mode was analyzed. For microleakage analysis, class V restorations were performed on extracted premolars, which were sectioned and stored in pH 4-, 7-, and 10-buffered fluorescent 0.02% rhodamine B dye. The specimens were observed under a confocal laser scanning microscope (CLSM) and scored using the acquired images. There were no significant differences in the μTBS according to the type of material (p = 0.518). The giomer showed a decreased bond strength under the pH 4 condition compared with the immediately tested or pH 7-stored specimens (p ≤ 0.043). In the microleakage analysis, the class V restoration with giomer showed a higher microleakage than RMGI or alkasite (p = 0.001). For RMGI and alkasite, the specimens stored at pH 4 showed a significantly lower microleakage than those stored at pH 7 (p = 0.028). RMGI and alkasite can be adopted as restorative materials in generalized or localized low-pH conditions.

Clinical Effectiveness of Ion-Releasing Restorations versus Composite Restorations in Dental Restorations: Systematic Review and Meta-Analysis

“…Ion-releasing restorations (IRRs), such as glass ionomers (GICs), are known for their fluoride-releasing properties [ 6 ], which are believed to contribute to caries prevention by providing an oral environment that inhibits demineralization of surrounding enamel, and for their biocompatibility with surroundings tissues [ 7 , 8 , 9 ]. However, marginal adaptation is a crucial point to consider, because its absence could cause secondary problems, and it may not fit the aesthetic expectations of patients [ 10 ]. The durability and resistance of IRRs under occlusal loading conditions and other stressors have also shown limitations [ 11 ].…”