Metal elements in tissue with dental peri-implantitis: a pilot study.
OBJECTIVE
Dental peri-implantitis is characterized by a multifactorial etiology. The role of metal elements as an etiological factor for peri-implantitis is still unclear. The aim of this study was to investigate the incidence of metal elements in bone and mucosal tissues around dental Grade 4 CP titanium implants with signs of peri-implantitis in human patients.


METHODS
In this prospective pilot study, all patients were enrolled consecutively in two study centers. Bone and soft tissue samples of patients with peri-implantitis with indication for explantation were analyzed for the incidence of different elements (Ca, P, Ti, Fe) by means of synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) and polarized light microscopy (PLM). The existence of macrophages and lymphocytes in the histologic specimens was analyzed.


RESULTS
Biopsies of 12 patients (seven bone samples, five mucosal samples) were included and analyzed. In nine of the 12 samples (75%), the SRXRF examination revealed the existence of titanium (Ti) and an associated occurrence with Iron (Fe). Metal particles were detected in peri-implant soft tissue using PLM. In samples with increased titanium concentration, lymphocytes were detected, whereas M1 macrophages were predominantly seen in samples with metal particles.


CONCLUSIONS
Titanium and Iron elements were found in soft and hard tissue biopsies retrieved from peri-implantitis sites. Further histologic and immunohistochemical studies need to clarify which specific immune reaction metal elements/particles induce in dental peri-implant tissue.
Department of Oral and Craniomaxillofacial Surgery, Center for Dental Medicine, University Medical Center Freiburg, Freiburg, Germany.
Tobias
T
Fretwurst
BAM Federal Institute for Materials Research and Testing, Berlin, Germany.
Guenter
G
Buzanich
Department of Oral and Maxillofacial Surgery, Navigation and Robotics, Charité Campus Virchow, Berlin, Germany.
Susanne
S
Nahles
Department of Operative Dentistry and Periodontology, Center for Dental Medicine, University Medical Center, Freiburg, Germany.
Johan Peter
JP
Woelber
BAM Federal Institute for Materials Research and Testing, Berlin, Germany.
Heinrich
H
Riesemeier
Department of Oral and Craniomaxillofacial Surgery, Center for Dental Medicine, University Medical Center Freiburg, Freiburg, Germany.
Katja
K
Nelson
D000368:Aged; D000539:Alveolar Process / Q000737:chemistry; D015921:Dental Implants / Q000009:adverse effects*; D005260:Female; D005881:Gingiva / Q000737:chemistry; D006801:Humans; D007501:Iron / Q000009:adverse effects / Q000032:analysis; D008297:Male; D008859:Microscopy, Polarization; D008875:Middle Aged; D057873:Peri-Implantitis / Q000209:etiology*; D010865:Pilot Projects; D011446:Prospective Studies; D013052:Spectrometry, X-Ray Emission; D014025:Titanium / Q000009:adverse effects* / Q000032:analysis
D015921:Dental Implants; D014025:Titanium; D007501:Iron
PLM; metal elements; peri-implantitis; synchrotron radiation X-ray fluorescence spectroscopy; titanium