铅线（英文：lead line 或 Burton's line），为一种铅中毒。1840年由英国的亨利·巴顿医师所纪录，主要为铅所引起的临床标志。患者可以看到牙龈会出现紫蓝色的铅线（很少见于幼儿）。铅在人体内里的反应会造成与口腔细菌活动的硫磺离子，在牙和牙龈上的连接点产生。
英语百科
Burton line 齿龈铅线
The Burton line or Burtonian line is a clinical sign found in patients with chronic lead poisoning. It is a very thin, black-blue line visible along the margin of the gums, at the base of the teeth.
The sign was described in 1840 by Henry Burton:
A similar line, the "bismuth line", occurs in people who have ingested bismuth compounds; bismuth, however, is of very low toxicity.