DOI: 10.11607/jomi.10745Language: EnglishChao, Denny / Komatsu, Keiji / Matsuura, Takanori / Cheng, James / Stavrou, Stella C. / Jayanetti, Jay / Chang, Ting-Ling / Ogawa, Takahiro
Purpose: Laser-created titanium surface topographies enhance soft tissue attachment and implant
stability. However, knowledge about the underlying mechanisms governing the tissue-level
reaction is lacking. The objective of this study was to examine the behavior and function of
human gingival fibroblasts growing on healing abutments with or without laser-textured
topography. Materials and methods: Human primary gingival connective tissue fibroblasts were
cultured on healing abutments with machined or laser-textured (Laser-Lok, BioHorizons)
surfaces. Cellular and molecular responses were evaluated by cell density assay (WST-1),
fluorescence microscopy, qRT-PCR, and detachment test. Results: The machined surface showed
mono-directional traces and scratches from milling, whereas the laser-textured surface showed a
distinct morphology consisting of mono-directional meso-scale channels (15 μm pitch) and
woven, oblique micro-ridges formed within the channel. There were no differences in initial
fibroblast attachment, subsequent fibroblast proliferation, nor collagen production between the
machined and laser-textured surfaces. Fibroblasts growing on laser-textured surface spread
mono-directionally along the meso-channels, while cells growing on machined surfaces spread
randomly. Fibroblasts on laser-textured surfaces were 1.8-times more resistant to detachment
than those on machined surfaces. An adhesive glycoprotein (fibronectin) and trans-membrane
adhesion linker gene (integrin beta-1) were upregulated on laser-textured surfaces. Conclusions:
The increased fibroblast retention, uniform growth, increased transcription of cell adhesion
proteins compellingly explain the enhanced tissue-level response to laser-created, hybrid textured
titanium surfaces. These results provide a cellular and molecular rationale for the tissue
reaction to this unique surface and support its extended use from implant fixtures and healing
abutments to diverse prosthetic components where enhanced soft tissue responses would be
desirable.
Keywords: Laser-Lok, microchannels, abutments, implant, soft tissue attachment, laser-textured
