Sealing Ability of Direct Adhesive Restorations in Posterior Teeth

Abstract

Contraction stress at the bonding interfaces may occur as a result of polymerisation shrinkage of resin composite. This may affect the restorative seal. Observing the fluid flow within dentine can be used to assess the seal of a restoration. Objectives: The aim of this study was to investigate effects on the restoration-dentinal seal using different placement methods with various direct adhesive systems and restorative materials. Methods: Mesio-occluso-distal cavities were prepared on extracted third molars (n=42). Prepared teeth were divided into 6 groups and restored with either: Sonic activated bulk-fill resin composite, SonicFill™; Conventional nano-hybrid resin composite, Herculite® Ultra; Herculite® Ultra with a resin-modified glass-ionomer cement (RMGIC) base, Riva light-cure HV; Herculite® Ultra with a glass-ionomer cement (GIC) base, Riva self-cure HV; Conventional nano-hybrid resin composite, Filtek™ Supreme XTE with selective enamel etch-and-rinse adhesive, and; Filtek™ Supreme XTE with no separate etch-and-rinse step. Either a two-step self-etch bonding system, Optibond XTR and a one-step bonding system, Scotchbond Universal Adhesive was used. Using an automated flow-recording device, fluid flow was assessed before, during, and at periods after restoration, at 24-hours, 1-week, 1-month and 4-months. Fluid flow rates of the different restorative procedures, and post-restoration time intervals were analysed using ANOVA. The changes in flow rates between the different restorations were compared using Tukey’s test (p<0.05). Results: There were no statistically significant differences in the mean percentage change in fluid flow rates between the restorative procedures after placement of the bonding agent, with or without a base. Immediately post-restoration, all test groups had increased fluid flow rates compared with baseline values. Conclusion: None of the different adhesive restorative materials were able to provide a complete seal to prevent fluid movement. Placement of RMGIC/GIC base produces a restorative seal that is comparable to that of teeth restored with only resin composite. Student Presenter This abstract is based on research that was funded entirely or partially by an outside source: NHMRC grant ID: 1039604