Primary surface measurement reported
Saline contact angle on titanium discs before and after vacuum plasma treatment, used to evaluate surface hydrophilicity on machined and rough surfaces.
Client Citation Analysis
Plasma Treatment to Remove Titanium Surface Contaminants and Improve Implant Biocompatibility: An In Vitro Study
This in vitro study evaluates vacuum plasma treatment on machined and rough titanium discs, with Dropometer-measured saline contact angle used as the direct hydrophilicity readout alongside contamination, cell-attachment, morphology, and gene-expression analyses.
At-a-Glance Summary
Dropometer attribution in the paper
The wettability test was conducted using “a tensiometer (Droplet Lab, Droplet Biosciences, Cambridge, MA, USA)” to measure the contact angle of a saline droplet on titanium surfaces.
How the surface-tension / contact-angle data were used in the study
The contact-angle data were used to compare titanium surface hydrophilicity before and after plasma treatment on machined and rough discs. The authors interpreted the lower post-treatment contact angles together with reduced carbon contamination and improved early fibroblast and osteoblast attachment.
Replication / reliability statement
Five machined and five rough-surfaced titanium discs were used for wettability testing, with the same discs measured before and after treatment to ensure consistency.
Paper Details
Title
Plasma Treatment to Remove Titanium Surface Contaminants and Improve Implant Biocompatibility: An In Vitro Study
Authors
Kailing Ho; Takahiko Shiba; Chia-Yu Chen; David M. Kim
Journal
Biomimetics
Year
2025
Volume
10
Pages / Article
571
License
CC BY 4.0
Journal context
What it is
Journal-level metrics for the publication venue (not a rating of this specific article).
How to read it
Compare metrics within category; updates are annual and lag current-year publications.
Scopus metrics (Elsevier / Scopus rating 2024)
CiteScore 2024
4.2
CiteScore subject ranks (CiteScore 2024)
- Q3 - Engineering, Biomedical Engineering (168/323)
- Q3 - Materials Science, Biomaterials (89/140)
SNIP 2024
0.967
SJR 2024
0.647
Journal Impact Factor (Clarivate JCR)
Journal Impact Factor (JCR 2024)
3.9
5-Year Impact Factor
4.0
JCR category rank
- Q1 - Engineering, Multidisciplinary;
- Q3 - Materials Science, Biomaterials
What Was Measured
Primary surface / interfacial measurement
The paper reports titanium-surface hydrophilicity by measuring the contact angle of a saline droplet before and after plasma treatment. Reported values decreased from 83.1° to 24.1° on machined discs and from 77.3° to 15.7° on rough discs.
Supporting measurements
Supporting measurements included SEM surface-topography imaging, EDS-based carbon analysis, cell viability assays for fibroblast and osteoblast adherence, immunohistochemistry staining of actin cytoskeleton and nuclei, SEM imaging of cell morphology, and RNA sequencing for differential gene expression.
Role of the Dropometer
The Dropometer appears in the methods as a tensiometer used for a wettability test on titanium discs. The authors placed a saline droplet on the surface and measured contact angle before and after 30 s vacuum plasma treatment on both machined and rough-surfaced Grade 4 titanium discs, using the same discs for paired before/after comparison.
In the study workflow, the Dropometer supplied the direct hydrophilicity readout that the authors used to quantify the plasma-induced surface shift and relate that shift to subsequent cell-response findings.
Key Findings
Marked hydrophilicity increase
Plasma treatment produced a strong reduction in saline contact angle on both titanium surface types. Machined discs shifted from 83.1° to 24.1°, and rough discs shifted from 77.3° to 15.7°, with both reductions reported as statistically significant at p < 0.0001.
Cleaner surface with preserved microtopography
EDS analysis showed carbon content decreasing from 2.60% to 1.87%, a 28.1% reduction after plasma treatment. SEM imaging at 10,000× showed the titanium surface architecture was preserved during treatment.
Earlier fibroblast attachment
Fibroblast adherence on machined titanium discs was higher at the 1, 2, and 6 h time points after plasma treatment. Immunohistochemistry and SEM also showed broader cytoskeletal spread and more spread-out pseudopodia morphology at early time points.
Earlier osteoblast attachment
Osteoblast adherence on rough titanium discs was higher at the 1 and 2 h time points after plasma treatment. IHC and SEM images showed more spread-out morphology, and by 24 h osteoblasts in the plasma group displayed a long, spindle-shaped, well-attached morphology.
Fibroblast transcriptional response at 6 h
RNA sequencing identified two genes as significantly upregulated in plasma-treated fibroblasts at 6 h versus the no-plasma group: Apln (log2 fold change = 1.90, FDR = 3.9 × 10−2) and Crabp2 (log2 fold change = 3.13, FDR = 1.4 × 10−4). The paper links these genes to angiogenesis and cell growth differentiation.
Figures & Visuals
Figure 5 — Direct Dropometer output
What it shows
This figure shows the saline-droplet contact-angle images and before/after distributions for machined and rough titanium surfaces, making it the central visual for the Dropometer-derived hydrophilicity result.
Figure 4 — Surface chemistry context for wettability shift
What it shows
This figure shows EDS-based carbon mapping and the reduction in carbon percentage by weight after plasma treatment, providing chemical context for the hydrophilicity change seen in Figure 5.
Figure 6 — Fibroblast adherence response
What it shows
This figure shows that the plasma-treated machined surfaces had higher fibroblast adherence at early time points, connecting the wettability shift to the soft-tissue-facing cell model used in the study.
Figure 7 — Osteoblast adherence response
What it shows
This figure shows higher early osteoblast adherence on plasma-treated rough surfaces, linking the surface hydrophilicity result to the implant-body-facing cell model.
Why It Matters
In this paper, the Dropometer-generated contact-angle data are the study’s direct surface-level evidence that vacuum plasma treatment shifts titanium toward a more hydrophilic state. That shift sits at the center of the authors’ interpretation of plasma bioactivation, alongside reduced carbon contamination and preserved surface architecture.
Within the paper’s implant-biomaterials context, the wettability data help connect a fast chairside plasma step with early biological events on titanium, including stronger early fibroblast and osteoblast attachment and a fibroblast gene-expression response at 6 h. The authors frame these results around improved implant biocompatibility and early healing-related interactions on implant and abutment surfaces.
Practical Takeaways
Direct hydrophilicity readout
The Dropometer provided the quantitative surface readout that distinguishes untreated from plasma-treated titanium in this study. The contact-angle shift was large on both machined and rough discs.
Useful paired before/after design
The same discs were measured before and after treatment, which made the wettability comparison tightly matched to the plasma intervention. That design strengthens the study’s surface-level comparison.
Relevant across two implant-facing surface types
The authors used the Dropometer on both machined and rough titanium surfaces, aligning the wettability test with abutment-like and implant-body-like use cases inside the study design.
Best interpreted with complementary assays
In this paper, the contact-angle result gains value when read together with EDS carbon reduction, cell-attachment assays, morphology imaging, and RNA sequencing. The study uses that combined workflow to interpret plasma treatment as a surface-bioactivation step.
Strong fit for early-stage response studies
The most prominent biological differences appeared at early time points, making the Dropometer readout especially relevant as an upstream indicator of the surface state the cells first encounter.