Shear bond strength evaluation of bioactive restorative materials on pretreated carious dentin-influence on silver diamine fluoride, potassium iodide, and glutathione

Abstract

Background: Silver diamine fluoride (SDF) has gained popularity for its caries-arresting properties, yet its tendency to cause esthetic concerns due to black-staining limits its widespread acceptance.

Aim: The aim of the study was to evaluate and compare the shear bond strength of Activa BioActive and Giomer restorative material with different protocols of SDF pretreatment on carious dentin.

Materials and methods: Ninety-two extracted teeth were decoronated at the cementoenamel junction, sectioned 1 mm into dentin, mounted in acrylic resin and randomly divided into four (n = 8) control and six (n = 10) experimental groups. Seventy-six samples underwent demineralization process for a period of 14 days for artificial carious dentin (ACD) formation. The samples categorized based on the dentin substrate (sound or ACD) were subjected to various SDF pretreatment protocols, i.e., only SDF, SDF with potassium iodide (KI), and SDF with glutathione (GSH). Further, bioactive restorative materials, i.e., Activa BioActive and Giomer (Beautifil II), were placed on it, and the samples were subjected to shear bond strength testing.

Statistical analysis: Independent t-test was run to analyze the values obtained.

Results: Giomer exhibited better mean bond strength with SDF, SDF + KI, and SDF + GSH (6.56, 4.67, and 3.34 mega-pascals [MPa], respectively) compared to Activa BioActive (3.42, 3.27, and 2.96 MPa, respectively).

Conclusion: This study contributes to understanding the interplay between SDF application protocols, esthetic concerns, and the adhesive properties of bioactive restorative materials. Giomer exhibited enhanced bond strength after SDF application, unlike Activa BioActive. In addition, incorporation of KI or GSH adversely affected the bond strength of both the restorative materials, underscoring the critical need for cautious clinical application.

Clinical relevance: This study highlights the importance of selecting appropriate dentin pretreatment agents to maximize the bond strength of bioactive restorative materials with carious dentin. SDF application significantly enhanced the bond strength of Giomer with carious dentin compared to Activa BioActive, thus, making it a good choice for restoring nonesthetic areas. In addition, the application of KI or GSH to mitigate discoloration of carious dentin negatively affected the bond strength of both, Activa BioActive and Giomer. Thus, the clinicians should weigh the benefits of SDF against potential bond strength reductions when using KI or GSH, especially for esthetic restorations.

Keywords: Activa BioActive; Beautifil II; Giomer; bioactive restorative materials; carious dentin; dentin pretreatment; glutathione; potassium iodide; silver diamine fluoride.

Figure 1

(a) Dentine slice, (b) dentin slice mounted on self-cure acrylic resin, (c) restorative material application, (d) shear bond strength testing

Figure 2

Shear bond strength (megapascals) of Giomer and Activa BioActive restorative materials to only Silver diamine fluoride (SDF), SDF with potassium iodide, and SDF + glutathione-treated carious dentin. SDF: Silver diamine fluoride, KI: Potassium iodide, GSH: Glutathione