A Novel Approach for Enhanced Nanoparticle‐Sized Bone Substitute Adhesion to Chemically Treated Peri‐Implantitis–Affected Implant Surfaces: An In Vitro Proof‐of‐Principle Study

Background: The objective of this study is to evaluate micro and nano‐hydroxyapatite (NHA) blended clot adhesion to citric acid–conditioned peri‐implantitis–affected surfaces. Methods: Forty hopeless implants with peri‐implantitis designated for removal were included in this study. Implants were divided into eight groups of five each: group 1 (G1) test areas were coated with hydroxyapatite of a microparticle size (MHA); group 2 (G2) test areas were coated with NHA; group 3 (G3) implants were coated with MHA after surface conditioning using citric acid; group 4 (G4) samples were treated in the same manner as in G3 except for the use of NHA; group 5 (G5) samples were coated without surface treatment with MHA mixed with whole human blood; group 6 (G6) implant samples were treated in the same manner as in G5 except for the use of NHA; group 7 (G7) implant samples were treated in the same way as in G5 plus surface conditioning using citric acid; and group 8 (G8) samples were treated in the same manner as in G7 except for the use of NHA. All implants in all groups were agitated for 3 minutes in phosphate‐buffered saline. All samples were prepared for scanning electron microscopy evaluation. Results: G1 and G2 non‐etched implants coated with MHA or NHA sizes were devoid of any bone particle adhesion to the peri‐implantitis–affected surfaces. Contrary to the lack of microparticle adhesion to the root surface that was seen in G3, G4 acid‐treated and NHA‐coated samples revealed nearly complete coverage of the peri‐implantitis–affected parts by the graft material. G5 non‐etched, clot‐blended MHA showed some areas of clot‐blended graft adhesion covering 6.7% of the examined surfaces. G6 non‐etched, clot‐blended NHA showed NHA retention within the fibrin strands in areas where the implant surface pores were exposed (24.3%). G7 acid‐treated and clot‐blended MHA‐treated implant surfaces showed partial coverage of the implant surface with detached fibrin clot–blended graft material (31.4%). G8 acid‐treated and NHA clot‐blended graft‐coated implants showed complete coverage of the implant surface by the clot‐blended graft material (93.4%). Conclusion: Peri‐implantitis–affected surface conditioning with citric acid improves NHA‐blended clot adhesion to titanium implant surfaces.