Assessment of bonding effectiveness and fracture mechanics of different Adhesive systems to hypomineralized primary tooth enamel – An in - vitro study

Abstract

Abstract Objective: To evaluate micro shear bond strength of different adhesives in hypomineralized primary teeth enamel. Material and methods: A total of Thirty-five primary maxillary and mandibular molars were made in to 115 sections were preserved in 10% neutral buffered formalin at room temperature until sample preparation and utilized for the study. after discarding of 15 broken samples, 110 sections were utilized and divided in to four groups, control enamel group [with group I (N=25) and group II (N=25)] and hypomineralized enamel group [with group III (N=25) and group IV (N=25)]. The teeth samples were color coded and mounted in the acrylic block. Teeth were positioned horizontally and faced a wet 600-grit silicon carbide finishing paper to provide flat enamel surfaces with a 2 to 3 mm diameter surface roughness and shear bond strength was tested using Universal Testing Machine. The fractured surfaces were evaluated for failure modes using light microscopy. Result: The bond strength of G-Premio bond is 21.56±6.72 MPa in control enamel and 12.8±1.52 MPa in hypo mineralized enamel. There exists a significant bond strength difference between both the adhesives to hypomineralized enamel (GC SOLARE universal bond= 7.07±3.90 MPa vs G- PREMIO bond 12.8±1.52 MPa; P≤.001). The most common failure is the cohesive failure Conclusion: The present study indicates that the overall bonding of both adhesives to hypomineralized tooth is less effective than bonding to “normal” enamel. However, the shear bond strength of G-Premio bond to control enamel and hypomineralized enamel is significantly greater than GC Solare Universal Bond. Clinical relevance: Restorative care of teeth with hypomineralization is difficult, and treatment decisions are influenced by a variety of factors including the severity of the disease, compliance and adhesive properties of the materials used and This is the first study to look at how self-etching adhesives affect hypomineralized primary enamel and helps in bonding strength of the affected enamel and based on this study results the bond strength of GP bond to control enamel and hypomineralized enamel is significantly greater than GC Bond.