One-shot Nano-device for Treatment of Peri-implantitis: Biological Proof of Concept

Abstract

Objectives To compare biological effects of experimental nano device composed of nano-hydroxyapatite loaded with clindamycin, embedded in PLGA for continual release of daily MIC against Porphiromonas gingivalis for 21 days bone healing period (CLHap) with effects of nano-hydroxyapatite (Hap) and commercial bone substituent (BioOssÒ). Methods 6 female beagle dogs with similar characteristics underwent teeth extractions, implant placement and ligature induced PI, and were further surgically treated. Following open-flap debridement, the biomaterials were randomly allocated to ensure the serial distribution of antimicrobial material for pharmacokinetic testing of antibiotic systemic release. The biochemical and microbiological markers were compared before disease induction (baseline), before the treatment (pre-op) and 3 months (3m) following treatment. GM-CSF, TNFa, IL-6, IL-10 and OPG concentrations were estimated using Luminex method, while the RT-PCR kit was developed for quantification of the Porphyromonas gulae. Finally, following animal sacrifice, specimens were retrieved for histological analyses. Following fracture technique, decalcified samples were sectioned and stained for histomorphometric assessment of: apical extension of barrier epithelium (aBE), infiltrated connective tissue (ICT) area and respective apical extension (aICT). Results The pharmacokinetic test confirmed safety of the experimental material according to undetectable blood concentrations of the antibiotic. The concentrations of P. Gulae, GM-CSF, TNFa, OPG, IL-6 and IL-10 significantly decreased following treatment only in CLHap group while in other groups the changes remained insignificant. Both ICT and aICT were significantly lower CLHap when compared to both control groups. Conclusions Results of the present study demonstrated safe and promising treatment capacity of the experimental CLHap for managment of peri-implantitis.