Apatite-coated implant surfaces exhibit superior biological, immunological, and mechanical properties compared to sandblasted acid-etched surfaces

apatite-coated-implant-surfaces-exhibit-superior-biological,-immunological,-and-mechanical-properties-compared-to-sandblasted-acid-etched-surfaces
Apatite-coated implant surfaces exhibit superior biological, immunological, and mechanical properties compared to sandblasted acid-etched surfaces

Scientific Reports , Article number:  (2026) Cite this article

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Abstract

Implant surface modification techniques have shifted from simple mechanical modifications to sophisticated strategies aimed at modulating biological responses at the bone–implant interface. This study aimed to compare sandblasted, large-grit, acid-etched (SLA) and apatite-coated dental implant surfaces, focusing on their biological, immunological, and mechanical performance. Surface morphology and wettability were assessed by field emission scanning electron microscopy and liquid spreading tests, respectively. In vitro assays evaluated osteoblast adhesion, alkaline phosphatase (ALP) staining, and mineralization. In vivo performance was examined using rat femoral condyle loosening and calvarial defect models to assess early bone formation, macrophage polarization, and vascular endothelial growth factor (VEGF) expression. A beagle mandibular tooth extraction model was used to measure removal torque (RT) and bone-to-implant contact (BIC). The apatite-coated surface exhibited a uniform nanostructured apatite layer with superior wettability compared to the SLA surface. In vitro, apatite-coated surface significantly enhanced osteoblast adhesion and mineralization (p < 0.05). In vivo, apatite-coated surface promoted peri-implant bone formation, accelerated the shift from M1 to M2 macrophages, and increased VEGF expression. In the beagle model, apatite-coated implants demonstrated higher RT and BIC at all time points. Apatite-coated on dental implants enhances osseointegration through combined biological, mechanical, and immunomodulatory effects, promoting rapid bone healing and stable implant fixation.

Data availability

Raw datasets supporting the findings of this study are available from the corresponding author upon reasonable request.

References

  1. Wennerberg, A. & Albrektsson, T. Effects of titanium surface topography on bone integration: A systematic review. Clin. Oral Implants Res. 20(Suppl 4), 172–184 (2009).

    Google Scholar 

  2. Coelho, P. G. et al. Basic research methods and current trends of dental implant surfaces. J. Biomed. Mater. Res. B Appl. Biomater. 88(2), 579–596 (2009).

    Google Scholar 

  3. Dohan Ehrenfest, D. M., Coelho, P. G., Kang, B. S., Sul, Y. T. & Albrektsson, T. Classification of osseointegrated implant surfaces: Materials, chemistry and topography. Trends Biotechnol. 28(4), 198–206 (2010).

    Google Scholar 

  4. Puleo, D. A. & Nanci, A. Understanding and controlling the bone-implant interface. Biomaterials 20(23–24), 2311–2321 (1999).

    Google Scholar 

  5. Le Guehennec, L., Soueidan, A., Layrolle, P. & Amouriq, Y. Surface treatments of titanium dental implants for rapid osseointegration. Dent. Mater. 23(7), 844–854 (2007).

    Google Scholar 

  6. Lang, N. P., Jepsen, S. & Working, G. Implant surfaces and design (Working Group 4). Clin. Oral Implants Res. 20(Suppl 4), 228–231 (2009).

    Google Scholar 

  7. Fernandes, D. J., Marques, R. G. & Elias, C. N. Influence of acid treatment on surface properties and in vivo performance of Ti6Al4V alloy for biomedical applications. J. Mater. Sci. Mater. Med. 28(10), 164 (2017).

    Google Scholar 

  8. Yum, H., Han, H. S., Kim, K., Kim, S. & Cho, Y. D. The cumulative survival rate of sandblasted, large-grit, acid-etched dental implants: A retrospective analysis. J. Periodontal. Implant Sci. 54(2), 122–135 (2024).

    Google Scholar 

  9. Zhang, T. et al. Chitosan/hydroxyapatite composite coatings on porous Ti6Al4V titanium implants: In vitro and in vivo studies. J. Periodontal. Implant Sci. 50(6), 392–405 (2020).

    Google Scholar 

  10. Tallarico, M. et al. Role of new hydrophilic surfaces on early success rate and implant stability: 1-year post-loading results of a multicenter, split-mouth, randomized controlled trial. Eur. J. Dent. 15(1), 1–7 (2021).

    Google Scholar 

  11. Ko, Y. C. et al. A randomized controlled trial of immediate implant placement comparing hydroxyapatite nano-coated and uncoated sandblasted/acid-etched implants using a digital surgical guide. Int. J. Implant Dent. 10(1), 29 (2024).

    Google Scholar 

  12. Shirazi, S., Ravindran, S. & Cooper, L. F. Topography-mediated immunomodulation in osseointegration, ally or enemy. Biomaterials 291, 121903 (2022).

    Google Scholar 

  13. Park, Y. S., Yi, K. Y., Lee, I. S., Han, C. H. & Jung, Y. C. The effects of ion beam-assisted deposition of hydroxyapatite on the grit-blasted surface of endosseous implants in rabbit tibiae. Int. J. Oral Maxillofac. Implants. 20(1), 31–38 (2005).

    Google Scholar 

  14. Hotchkiss, K. M., Ayad, N. B., Hyzy, S. L., Boyan, B. D. & Olivares-Navarrete, R. Dental implant surface chemistry and energy alter macrophage activation in vitro. Clin. Oral Implants Res. 28(4), 414–423 (2017).

    Google Scholar 

  15. Choi, S. M. & Park, J. W. Multifunctional effects of a modification of SLA titanium implant surface with strontium-containing nanostructures on immunoinflammatory and osteogenic cell function. J. Biomed. Mater. Res. A. 106(12), 3009–3020 (2018).

    Google Scholar 

  16. Wheeler, K. C. et al. VEGF may contribute to macrophage recruitment and M2 polarization in the decidua. PLoS ONE 13(1), e0191040 (2018).

    Google Scholar 

  17. Liang, B., Wang, H., Wu, D. & Wang, Z. Macrophage M1/M2 polarization dynamically adapts to changes in microenvironment and modulates alveolar bone remodeling after dental implantation. J. Leukoc. Biol. 110(3), 433–447 (2021).

    Google Scholar 

  18. Hotchkiss, K. M., Clark, N. M. & Olivares-Navarrete, R. Macrophage response to hydrophilic biomaterials regulates MSC recruitment and T-helper cell populations. Biomaterials 182, 202–215 (2018).

    Google Scholar 

  19. Bai, L. et al. Differential effect of hydroxyapatite nano-particle versus nano-rod decorated titanium micro-surface on osseointegration. Acta Biomater. 76, 344–358 (2018).

    Google Scholar 

  20. Shah, F. A. et al. Laser-modified surface enhances osseointegration and biomechanical anchorage of commercially pure titanium implants for bone-anchored hearing systems. PLoS ONE 11(6), e0157504 (2016).

    Google Scholar 

  21. Johansson, C. B. & Albrektsson, T. A removal torque and histomorphometric study of commercially pure niobium and titanium implants in rabbit bone. Clin. Oral Implants Res. 2(1), 24–29 (1991).

    Google Scholar 

  22. Gotfredsen, K., Nimb, L., Hjorting-Hansen, E., Jensen, J. S. & Holmen, A. Histomorphometric and removal torque analysis for TiO2-blasted titanium implants. An experimental study on dogs. Clin. Oral. Implants Res. 3(2), 77–84 (1992).

    Google Scholar 

  23. Bosshardt, D. D., Chappuis, V. & Buser, D. Osseointegration of titanium, titanium alloy and zirconia dental implants: Current knowledge and open questions. Periodontol. 2000. 73(1), 22–40 (2017).

    Google Scholar 

  24. Albrektsson, T. & Wennerberg, A. On osseointegration in relation to implant surfaces. Clin. Implant. Dent. Relat. Res. 21(Suppl 1), 4–7 (2019).

    Google Scholar 

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Acknowledgements

This work was supported by the Creative-Pioneering Researchers Program through Seoul National University, Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. RS-2022-NR067350 and RS-2024-00349549), and Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (No. HI23C0544).

Funding

This work was supported by the Creative-Pioneering Researchers Program through Seoul National University, Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. RS-2022-NR067350 and RS-2024-00349549), and Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (No. HI23C0544).

Author information

Author notes

  1. Hee‑seung Han and Jaehyuk Hwang contributed equally to this work.

Authors and Affiliations

  1. Department of Periodontology, Korea University Anam Hospital, Seoul, Republic of Korea

    Hee‑seung Han

  2. Department of Periodontology, School of Dentistry and Dental Research Institute, Seoul National University and Seoul National University Dental Hospital, Seoul, Republic of Korea

    Jaehyuk Hwang, Sungtae Kim & Young-Dan Cho

  3. Bone Science Evaluation Team, Tissue Regeneration Institute, Osstem Implant Co. Ltd., Seoul, Republic of Korea

    Seung Hye Lee & Yongjoon Kim

Authors

  1. Hee‑seung Han
  2. Jaehyuk Hwang
  3. Seung Hye Lee
  4. Yongjoon Kim
  5. Sungtae Kim
  6. Young-Dan Cho

Contributions

Conceptualization: Sungtae Kim, Young-Dan Cho; Formal Analysis: Hee-seung Han, Jaehyuk Hwang, Seung Hye Lee, Yongjoon Kim; Investigation: Hee-seung Han, Jaehyuk Hwang, Seung Hye Lee, Yongjoon Kim, Sungtae Kim, Young-Dan Cho; Methodology: Young-Dan Cho; Project Administration: Sungtae Kim, Young-Dan Cho; Writing – Original Draft: Hee-seung Han, Jaehyuk Hwang, Young-Dan Cho; Writing- review & editing: Young-Dan Cho.

Corresponding author

Correspondence to Young-Dan Cho.

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Competing interests

The authors declare no competing interests.

Ethicals declarations

All animal procedures, including selection, housing, and surgical interventions, were reviewed and approved by the Osstem Institutional Animal Care and Use Committee (OST-IACUC-2002). All procedures were performed in accordance with a modified version of the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines.

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Han, H., Hwang, J., Lee, S.H. et al. Apatite-coated implant surfaces exhibit superior biological, immunological, and mechanical properties compared to sandblasted acid-etched surfaces. Sci Rep (2026). https://doi.org/10.1038/s41598-025-34417-1

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