Lead poisoning in adults characteristically produces a 'Burton's line' — a bluish-grey gingival line. The chemical basis of this line is formation of which compound in the gingival tissue?
- A Lead carbonate deposited at the gingival margin from dental plaque interactions
- B Lead phosphate precipitated from saliva at the gingival sulcus
- C Lead sulphide formed by reaction of lead with hydrogen sulphide produced by oral bacteria ✓
- D Lead oxide deposited from exogenous environmental exposure
Explanation
Burton's line (blue lead line) results from the deposition of lead sulphide (PbS) in the gingival tissue at the dentogingival junction. Oral bacteria (particularly Bacteroides and anaerobes in dental plaque) produce hydrogen sulphide (H2S) by reducing sulphate; this H2S reacts with circulating lead (Pb2+) deposited in gingival capillaries to form insoluble black/grey lead sulphide that appears as a bluish-grey line. The line is only present when adequate oral hygiene is poor — in edentulous individuals or those with good oral hygiene, this sign may be absent even with significant lead exposure.
Reference: The Essentials of Forensic Medicine and Toxicology (Narayan Reddy), 34th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.