Cytocompatibility of Direct Laser Interference-patterned Titanium Surfaces for Implants

Abstract

Abstract. In an effort to generate titanium surfaces forimplants with improved osseointegration, we used direct laser interference patterning (DLIP) Improving the osseointegration of implants is a key issue in dental implantation and surface modification is a major strategy for enhancing the attachment, proliferation and differentiation of cells in contact with such implants.For titanium implants, various methods are used to modify the surface roughness, including sandblasting, acid-etching, anodization, calcium-phosphate crystal deposition and chemical modification (1).A recently developed technique for surface modification is direct laser interference patterning (DLIP) (2, 3). By overlapping two or more laser beams on a sample surface, periodic laser intensity distributions are obtained and used for laser ablation. DLIP is a very cost effective process for treating surfaces because it is possible to structure metals at high speeds of up to 0.39 m 2 /min (4). The structure periodicity can be controlled at the micrometer to submicrometer range and the surface roughness at the micrometer to nanometer level. Moreover, some chemical features can be modified, for example, the material's wetting properties (5).In the present study, we modified the surface of titanium of four different structures and assessed in vitro cytoxicity and cell attachment, as well as the viability and proliferation of cells cultured directly on the surfaces. Materials and MethodsTitanium specimens and reference materials. Line-like structures with spatial periods (p) of 3, 5, 10 and 20 μm were produced on pure titanium (grade IV) samples (Figure 1). All specimens were cylindrical with a diameter of 10 mm and thickness of 1.5 mm. Before and after laser treatment they were cleaned in pure ethanol (C 2 H 5 OH) using ultrasonic cleaning for 5 min each. As a reference surface, standard grit-blasted and etched samples (TiPure Plus; Bego Implant Systems, Bremen, Germany) were used. The surface characteristics of the DLIP-treated variants and TiPure Plus gritblasted and acid-etched reference material are shown in Table I.As a positive control for the in vitro cytocompatibility tests, RM-A, a polyurethane film sheet containing 0.1% zinc diethyldithio-carbamate (Hatano Research Institute, Hadano, Kanagawa, Japan) was used. As a negative control, Wako plastic sheets (cat. no. 160-08893; Wako Chemicals GmbH, Neuss, Germany) were used.

Impact of Laser Structuring on Medical-Grade Titanium: Surface Characterization and In Vitro Evaluation of Osteoblast Attachment

“…However, the generated structures and phase compositions can have an impact on fatigue strength [27], whereby residual stress of the material can be reduced and fatigue strength can be increased by laser shock peening [28]. The in vitro cytocompatibility of all surfaces was supported in accordance with the ISO 10993-5 standard on the basis of WST-1, which is similar to the findings of Hartjen et al [29]. The vital osteoblast reaction in adhering and spreading across the surface, and especially the affinity to grow into the pores as well as partially cover them, is a further indication of a cytocompatible surface.…”

Research progress of metal biomaterials with potential applications as cardiovascular stents and their surface treatment methods to improve biocompatibility

“…Many surface treatment methods currently exist, including chemical methods [ 68 ] and physical methods [ 69 ]. Physical methods consist of milling [ 70 ], laser [ [71] , [72] , [73] ], sandblasting [ 74 , 75 ], and electrical discharge machining (EDM) [ 76 , 77 ], while chemical methods include acid [ 78 ] and alkali treatment [ 79 , 80 ], nitriding [ 81 , 82 ], and plasma treatment [ 83 , 84 ]. In addition, some electrochemical methods are available, such as electropolishing [ 85 , 86 ], electrolytic polishing [ 87 , 88 ], anodic oxidation [ 89 , 90 ], and micro-arc oxidation (MAO, also known as plasma electrolytic oxidation) [ 80 , 91 ].…”