Effect of Surface Treatments on the Adhesion of Self-Adhesive Resin Cements to Titanium

Purpose: To evaluate the effect of different chemical surface treatments on the adhesion of self-adhesive resin cements to commercially pure titanium (cp Ti) by means of strain energy release rate (G-value, J/m2). Materials and Methods: Machined cp Ti plates grade II were prepared and divided into ten groups in each test according to the surface treatment used; Gr 1: control, machined; Gr 2: sandblasted; Gr 3: methylene chloride (CH2Cl2) for 5 min; Gr 4: CH2Cl2 for 10 min; Gr 5: 10% hydrogen peroxide (H2O2) for 5 min; Gr 6: 10% H2O2 for 10 min; Gr 7: 30% H2O2 for 5 min; Gr 8: 30% H2O2 for 10 min; Gr 9: 9% hydrofluoric acid (HF) for 5 min; Gr 10: 9% HF for 10 min. For bond strength testing, each group was further divided into two subgroups according to the type of resin cement used (G-CEM and Rely × Unicem). Surface roughness examination and SEM analysis of treated cp Ti surfaces were carried out. Data were analyzed using ANOVA and Tukey's test. Statistical significance was set at the 0.05 probability level. Results: The cp Ti/G-CEM and cp Ti/Rely × Unicem (9% HF for 5 or 10 min) groups showed the highest G-values (13.7 ± 2.2, 13.8 ± 2.1, 11.6 ± 1.6 and 11.8 ± 1.2, respectively) among their groups. The sandblasted group showed the highest surface roughness value (3.4 ± 0.2 µm) when compared with other treated groups. Conclusion: Adhesion between resin cements and cp Ti can be improved by the use of certain chemical baths as surface treatments of titanium prior to cementation as alternative techniques to sandblasting treatment. Keywords: titanium, resin cements, adhesion, hydrofluoric acid, methylene chloride, hydrogen peroxide, surface roughness