In vitro comparison of titanium surface conditioning via boron-compounds and sand-blasting acid-etching

The aim of this study was to compare the effect of a boron-based titanium (Ti) surface treatment methods against the conventional sand-blasting & acid-etching method. A total of 216 machined titanium (Ti) discs were divided into four equal groups and the following surface treatments were applied; Aluminum oxide (Al2O3) sand-blasting and hydrochloric/ sulfuric acid (HCl/H2SO4) etching (SLA). Aluminum oxide (Al2O3) with boric acid (H3BO3) particle sand-blasting and tetrafluoroboric acid (HBF4) etching (SBF). Wetting of the SBF surface by boric acid-solution (SBF-B). Aluminum oxide (Al2O3) sandblasting and tetrafluoroboric acid (HBF4) etching (SAF). Confocal laser scanning microscopy, stylus profilometry, scanning electron microscopy and X-ray photoelectron spectroscopy were used for the quantification of the surface characteristics. Adhesion and viability of Porphyromonas gingivalis and Streptococcus mutans, osteocalcin production and viability of human fetal osteoblastic cells were quantified by cell cultures and lysate analyses. Results were analyzed by non-parametric tests (p<0.05). Surface area roughness parameters were similar in all specimens with an arithmetical mean height (Sa) of 1.6 (SD: 0.6) mu m. SBF-B surface yielded the highest cell viability/proliferation (187.5%, IQR: 37.5; p=0.0231), osteocalcin production (228.9 ng/ml IQR: 14.1; p<0.0001), and also the lowest adhesion rate for both bacteria (45 x 10(2) CFU/ml (IQR: 22.5 x 10(2))) and (290 x 10(3) CFU/ml (IQR: 45.5 x 10(3))) for P.gingivalis and S.mutans, respectively; p=0.0002). SLA, SBF and SAF surfaces revealed inferior outcomes as compared to the SBF-B surface. Within the limits of the in vitro investigation it can be concluded that, boric acid-wetting of the aluminum oxide-blasted, boric acid-blasted, and tetrafluoroboric acid etched Ti surface (SBF-B) increase osteoblast adhesion and reduce the bacterial adherence.