Effect of heat treatment on H2O2/HCl etched pure titanium dental implant: An in vitro study

BACKGROUND Surface chemistry of dental implant plays an important role in osseointegration. Heat treatment might alter surface chemistry and result in different biological response. The aim of this study was to investigate the roles of heat treatment of H2O2/HCl-treated Ti implants in cell attachment, proliferation and osteoblastic differentiation. MATERIAL/METHODS Sandblasted, dual acid-etched and H2O2/HCl heat-treated discs were set as the control group and sandblasted, dual acid-etched H2O2/HCl-treated discs were the test group. Both groups' discs were sent for surface characterization. MC3T3-E1 cells were seeded on these 2 groups' discs for 3 hours to 14 days, and then cell attachment, cell proliferation and cell differentiation were evaluated. RESULTS Scanning electron microscope analysis revealed that the titanium discs in the 2 groups shared the same surface topography, while x-ray diffraction examination showed an anatase layer in the control group and titanium hydride diffractions in the test group. The cell attachment of the test group was equivalent to that of the control group. Cell proliferation was slightly stimulated at all time points in the control group, but the alkaline phosphatase (ALP) activity and osteocalcin (OC) production increased significantly in the test group compared with those in the control group at every time point investigated (p<0.05 or p<0.01). Moreover, the osteoblastic differentiation-related genes AKP-2, osteopontin (OPN) and OC were greatly up-regulated in the test group (p<0.05 or p<0.01). CONCLUSIONS The results implied that surface chemistry played an important role in cell response, and H2O2/HCl etched titanium surface without subsequent heat treatment might improve osseointegration response.