@article{null,
  title={A follow-up study on three caries activity tests},
  author={sizhen shi,qing deng,yoshihiro hayashi,masashi yakushiji,yukio machida,qin liang},
  journal={Journal of Clinical Pediatric Dentistry},
  volume={27},
  number={4},
  pages={359--364},
  doi = {10.17796/jcpd.27.4.522043767n014735},
  year={2003}
}