Analysis of titanium and other metals in human jawbones with dental implants - A case series study.

OBJECTIVE: The aim of this study was to measure titanium (Ti) content in human jawbones and to show that Ti was released from dental implants inserted into these jawbones.

METHODS: Seven samples from four human subjects with dental implants were analysed as test group and six bone samples of similar topographical regions from six human subjects without implants served as control. The contents of various elements in human jawbones were detected by inductively coupled plasma optical emission spectrometry. The distributions of various isotopes in human mandibular bone were measured with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Histological analyses of undecalcified, Giemsa-Eosin stained mandible sections were performed by light microscopy and particles were identified in human bone marrow by scanning electron microscope-energy dispersive X-ray analysis.

RESULTS: In test group only Ti content was significantly higher compared to control group. The mean contents of Ti were 1940μg/kg in test group and 634μg/kg in control group. The highest Ti content detected in human mandibular bone was 37,700μg/kg-bone weight. In samples 4-7 (human subjects II-IV), increased Ti intensity was also detected by LA-ICP-MS in human mandibular tissues at a distance of 556-1587μm from implants, and the intensity increased with decreasing distance from implants. Particles with sizes of 0.5-40μm were found in human jawbone marrow tissues at distances of 60-700μm from implants in samples 4-7.

SIGNIFICANCE: Ti released from dental implants can be detected in human mandibular bone and bone marrow tissues, and the distribution of Ti in human bone was related to the distance to the implant.