Effects of Surface Treatments on Bonding Luting Cement to Dentin

Objectives: Objective: The purpose of this study was to determine whether the use of various materials commonly used in conjunction with the cementation of indirect dental restorations would enhance bond strengths of a resin modified glass ionomer cement to dentin without resorting to proprietary dentin conditioners.
Methods: Methods:One hundred thirty-five de-identified extracted human teeth were mounted in acrylic and ground to a flat dentin surface (600 grit final surface). Samples were randomly divided into nine groups (N=15). A control group consisted of samples with untreated dentin. Dentin surface treatments consisted of: 1) 2% Ferric Chloride, 2) 20% Ferric Sulfate, 3) a combination of 2% Ferric Chloride and 20% Ferric Sulfate, 4) 20% Polyacrylic Acid, 5) 25% Aluminum Chloride, 6) 20-30% Polyacrylic Acid, 7) water and flour of pumice, 8) water and flour of pumice followed by 2% Ferric Chloride. Surface treatments varied in pH from strong to weak acids.Prior to treatment, each sample was contaminated with human saliva, to simulate the acquired pellicle, rinsed in water for 10 seconds, and blotted dry. After treatment 2.5 X 4mm cylindrical-shaped Rexillium rods (600 grit end surface) were cemented to the flat ground dentin surfaces and stored in distilled water for 24 hours at 37°C. Shear bond strengths (SBS) were determined using an MTS Insight machine with a crosshead speed of 1mm per minute. Data were analyzed using ANOVA and Tukey's post hoc test.
Results: Results: ANOVA and Tukey's post hoc test showed that surface treatments in the range of 1.5-2.0 pH provided significantly (p<0.05) greater bond strengths over other treatment regimens.
Conclusions: Conclusion: Overall, dentin cleansing with moderate pH solutions can enhance SBS to dentin, in the absence of flour of pumice, prior to cementation. Thus, time and steps can be saved during the cementation procedure.