The evaluation of trustworthiness to identify health insurance fraud in dentistry.

•The Economist says 10% of health care expenditure ($272 billion) was wasted on fraudulent claims in 2012.•Previous studies aimed at other types of fraud are inadequate for solving cross-dentist health insurance fraud.•We devise a social-network-based risk evaluation to detect fraudulent claims in dentistry.•By experiment, using real-world or artificial data, our method can effectively identify undetected frauds in the past in dentistry claims data.•Integrating our method with previous research can provide higher accuracy.