The investigation of microbiologic and biochemical effectiveness of diamond like carbon coating over ti surfaces

The durability of surrounding soft tissue barrier has great effect on long term success of dental implants. This barrier prevents the bone-implant interface from the microorganisms and by this way it can reduce the risk of inflammation.As the antibacterial effect of Ti is supposed to be nominal, the polished transmucosal part of commertially pure Ti implants can be coated with hard coating materials which have excellent physical and biological properties.Diamond-Like Carbon (DLC) films are amorphous carbon based coatings containing sp2 and sp3 bonded carbon atoms with varying hydrogen concentrations. Their significantly high concentration of sp3 carbon bonds confers valuable `diamond-like? properties. Considering the excellent properties of DLC, especially the low surface roughness, DLC coating should be investigated as a film for reducing microbial adhesion and having positive effect on preventing inflammation.The purpose of this study is (i) to compare the surface roughness of DLC coated, TiN coated and polished Ti discs with AFM (ii) to compare the number of adhered S.mutans and S.sanguis on these surfaces (iii) to compare the amount of inflammation markers which were collected from the periimplant sulcus fluid of DLC coated, TiN coated and polished healing caps.DLC coated, TiN coated and commercially pure Ti disc shaped samples, each for 10, were prepared in diameter of 5mm and thickness of 2mm. After the surface preparations, surface topography of samples were examined with AFM. The same samples were incubated in a suspension containing S. mutans and S. sanguis, then the adhered bacteria were counted.For detecting the inflammation markers, the samples collected from the periimplant sulcus fluid of TiN and DLC coated and polished Ti healing caps were analyzed with ELISA.As a result of microbiolgical tests, according to the reduced surface roughness proven with AFM images, the decreased number of adhered bacteria on DLC coated discs were statistically significant.According to the ELISA test, it was found that the surface coatings have no effect on reducing the amount of inflammation markers at periimplant sulcus fluid. Hence no adverse effect has been found on application of diamond like carbon coating at transmucosal part of the implants.