Chlorhexidine delivery system from titanium/polybenzyl acrylate coating: evaluation of cytotoxicity and early bacterial adhesion.
OBJECTIVE
The formation of biofilms on titanium dental implants is one of the main causes of failure of these devices. Streptococci are considered early colonizers that alter local environment favouring growing conditions for other colonizers. Chlorhexidine (CHX) is so far the most effective antimicrobial treatment against a wide variety of Gram-positive and Gram-negative organisms as well as fungi. This study was designed to develop a CHX delivery system appropriate for healing caps and abutments, with suitable drug release rate, effective as antimicrobial agent, and free of cytotoxic effects.


METHODS
Polybenzyl acrylate (PBA) coatings with and without CHX (Ti/PBA and Ti/PBA-CHX, respectively) and different drug loads (0.35, 0.70, and 1.40%, w/w) were assayed. The cytotoxic effect of CHX released from the different substrates on UMR106 cells was tested by alkaline phosphatase specific activity (ALP), and microscopic evaluation of the cells. Non-cytotoxic drug load (0.35%, w/w) was selected to evaluate the antimicrobial effectiveness of the system using a microbial consortium of Streptococcus species.


RESULTS
The kinetic profile of CHX delivered by Ti/PBA-CHX showed an initial fast release rate followed by a monotonic increase of delivered mass over 48 h. The number of attached bacteria decreased in the following order: Ti>Ti/PBA>Ti/PBA-0.35.


CONCLUSIONS
PBA-0.35 coating is effective to inhibit the adhesion of early colonizers on Ti without any cytotoxic effect on UMR-106 cells.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, CCT-La Plata, 1900 La Plata, Argentina.
María C
MC
Cortizo
Tamara G
TG
Oberti
María S
MS
Cortizo
Ana M
AM
Cortizo
Mónica A
MA
Fernández Lorenzo de Mele
D000179:Acrylates / Q000737:chemistry* / Q000633:toxicity; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage* / Q000633:toxicity; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002710:Chlorhexidine / Q000008:administration & dosage* / Q000633:toxicity; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000633:toxicity; D003764:Dental Materials / Q000737:chemistry* / Q000633:toxicity; D004058:Diffusion; D016503:Drug Delivery Systems; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects; D051381:Rats; D013291:Streptococcus / Q000187:drug effects; D014025:Titanium / Q000737:chemistry* / Q000633:toxicity
D000179:Acrylates; D000891:Anti-Infective Agents, Local; D020099:Coated Materials, Biocompatible; D003764:Dental Materials; D014025:Titanium; D000469:Alkaline Phosphatase; C036658:acrylic acid; D002710:Chlorhexidine