{'fraction_non_alphanumeric': 0.03746978243352135, 'fraction_numerical': 0.016116035455278, 'mean_word_length': 4.828638497652582, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
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.