Energy dispersion spectroscopy analysis on failed implants: a preliminary survey

BACKGROUND: Peri-implantitis or implant infection is a biologic complication involving soft and hard tissues around implants. The prevalence of the disease was recently estimated between 12% and 14% according to studies dealing with the private practice, which is also consistent with university statistics. Different methods were presented to minimize or even to remove biofilm from contaminated surfaces completely. Chemical and air-abrasive treatments have been shown to be able to disrupt biofilm. Chemical cleaning solution in combination with mechanical debridement is ineffective to eliminate bacterial biofilm. Lasers and photodynamic therapy presented inconsistent results. Interestingly, implantoplasty remains a preferred way to remove infected contaminants. When re-osseointegration of these treated contaminated implant surfaces was assessed, the quality of the implant surface after decontamination dictates the outcome. No matter the type of intervention implemented to counteract peri-implantitis, implant failure sometimes remains an unavoidable outcome. In this in-vitro report, the authors propose an automated EDS analysis of the whole dental implant surface to determine the percentage directly involved by the bacterial biofilm on failed fixtures. METHODS: Samples morphology was studied using a Scanning Electron Microscope (SEM, Zeiss Evo 50 XVP with LaB6 source). The instrument is endowed with detectors for secondary and backscattered electrons collection, as well as energy dispersion spectroscopy (EDS) analyzer for elemental analysis. All the materials were observed using 10kV of voltage. Samples, soon after being collected and fixed in 4% paraformaldehyde, were covered with a golden layer of about 10 nm in order to avoid charge accumulation during SEM-EDS analysis. Automated EDS mapping was obtained on the entire surface. RESULTS: On the samples analyzed (N.=10), the mean surface covered by bacterial biofilm was 79.3±7.6% (Mean±95% CI) based on the percentage of titanium, oxygen, and phosphorous. As a control, direct observation of the samples was also performed owing to SEM images finding an optimal correlation between the automatic EDS mapping and human-driven quantification of the bacterial biofilm. CONCLUSIONS: Based on these preliminary data, EDS automatic mapping may be considered an exciting method to analyze failed implants. Furthermore, the possible future applications in this field, once the bacteria have been identified, could involve a more specific treatment with the aim of remove infected contaminants on the implant surfaces.