[Positive identification of dental porcelain in a case of murder]

Dental prostheses can provide important evidence for use in personal identification. In recent years, the variety of materials used in prostheses has increased with the diversification of dental treatment. The detailed analysis of these materials can provide significant information to assist in personal identification. This paper reports a case when identification was achieved by the comparative analysis of fragment of fused dental porcelain. In April, 1990, a woman aged 24 years was found murdered in her apartment in Hamamatsu City, Shizuoka Prefecture. Near her body a small mass of fused porcelain was recovered. Subsequently, a 48 year old male suspect was arrested. An examination of his teeth revealed a small fragment of dental porcelain adhering to an abutment tooth. This was removed for testing. The suspect denied the charge of murder. A comparative analysis of the porcelain found in the apartment and the porcelain that was removed from the suspect's abutment tooth, was carried out by scanning electron microscopy (SEM) and electron probe X-ray microanalysis (EPMA). The SEM examination demonstrated remarkable similarity in respect of the structure of the porcelain and the nature and distribution of the air bubbles produced during the baking process in both samples. The EPMA showed the elemental composition of each sample to be identical. This case demonstrated that detailed analysis of dental materials may affords a useful aid for personal identification.