Chemical Implant Surface Decontamination

Chemical surface decontamination involves the use of acidic and antimicrobial compounds to reduce biofilm on implant surfaces and they are often used in conjunction with nonsurgical and surgical regenerative approaches for treatment of peri-implant disease.¹⁰⁴ Commonly used chemical implant surface decontaminants include citric acid, chlorhexidine, ethylene diamine tetraacetic acid (EDTA), hydrogen peroxide, tetracycline, and saline.¹⁰⁴ Citric acid has a pH of 1 and has been used extensively for implant surface detoxification.¹⁰⁴ In vitro studies demonstrate endotoxin reduction and bacterial cell inactivation with citric acid applications ranging from 30 seconds to 2 minutes in smooth-surface and moderately rough implant surfaces.^118,119 Concentration of citric acid in studies were not consistent with concentrations ranging from 4-40%. Lower concentrations of citric acid demonstrated decreased osteoblastic cytotoxicity, but cell proliferation was impacted at all concentrations.^120,121 Chlorhexidine gluconate is a broad-spectrum antimicrobial and has demonstrated significant reduction in endotoxin and bacterial load on implant surfaces when applied to those surfaces.^118,122 Chlorhexidine has also been associated with induced apoptotic and autophagic/necrotic cell death of osteoblasts and fibroblasts.^123,124 EDTA is widely used in dentistry as a chelating agent and has the advantage of a neutral pH.¹⁰⁴ Little data is available on the clinical efficacy of EDTA for implant surface decontamination.¹⁰⁴ In vitro studies have demonstrated that hydrogen peroxide reduction of endotoxin and elimination of pathogenic bacteria from titanium surfaces.¹²⁵ Animal studies have also verified the capability of hydrogen peroxide to decontaminate implant surfaces in vivo and allow re-osseointegration.¹²⁶ Tetracycline is a bacteriostatic antibiotic that inhibits bacterial protein synthesis.¹⁰⁴ A slurry including tetracycline 50mg/mL applied to implant surfaces after resective implant surgery has been associated with arrest of peri-implant disease progression and radiographic bone fill.^127,128 Saline combined with mechanical implant surface debridement has been associated with clinical stability after treatment for up to 24 months.^129,130 It has also been reported that use of saline for decontamination provides similar results to other chemical disinfective processes and results in a more biocompatible surface with no deleterious effects on host tissues.¹³¹