formocresol and Drug-Hypersensitivity

Concern has been expressed about the safety of formocresol use in pediatric dentistry. Formaldehyde, a primary component in formocresol, is a hazardous substance and is considered a probable human carcinogen by the International Agency for Research on Cancer, Health Canada, the Agency for Toxic Substances and Disease Registry in the U.S. Department of Health and Human Services, and the U.S. Environmental Protection Agency. Humans inhale and ingest formaldehyde daily, however, and produce formaldehyde during cellular metabolism. The human body is physiologically equipped to handle formaldehyde through multiple conversion pathways. The resultant single carbon atom released during metabolism is deposited in the "1-carbon pool," which, in turn, is used for the biosynthesis of macromolecules including DNA and RNA. Reevaluation of earlier research that examined potential health risks associated with formaldehyde exposure has shown that this research was based on flawed assumptions, which resulted in erroneous conclusions. The purpose of this review was to examine more recent research about formaldehyde metabolism, pharmacokinetics, and carcinogenicity. These results indicated that formaldehyde is probably not a potent human carcinogen under low exposure conditions. Extrapolation of these research results to pediatric dentistry suggests an inconsequential risk associated with formaldehyde use in pediatric pulp therapy.

Topics: Animals; Carcinogens; Child; Dental Care for Children; Drug Hypersensitivity; Formocresols; Humans; Inactivation, Metabolic; Mutagens; Pulpotomy

Concern has been expressed about the safety of formocresol use in pediatric dentistry. Formaldehyde, a primary component in formocresol, is a hazardous substance and is considered a probable human carcinogen by Health Canada. However, humans inhale and ingest formaldehyde daily and also produce this compound as part of normal cellular metabolism. The human body is physiologically equipped to handle this exposure through multiple pathways for oxidation of formaldehyde to formate and incorporation into biological macromolecules via tetrahydrofolate-dependent one-carbon biosynthetic pathways. Recent re-evaluation of earlier research that examined potential health risks associated with formaldehyde exposure has shown that the research was based on flawed assumptions, which resulted in erroneous conclusions. This review examines more recent research about formaldehyde metabolism, pharmacokinetics and carcinogenicity, the results of which indicate that formaldehyde is probably not a potent human carcinogen under conditions of low exposure. Extrapolation of these research results to pediatric dentistry suggests an inconsequential risk of carcinogenesis associated with formaldehyde use in pediatric pulp therapy. Areas for further investigation are suggested.

Topics: Animals; Carcinogens; Dental Materials; Dental Pulp; DNA Damage; Dose-Response Relationship, Drug; Drug Hypersensitivity; Formaldehyde; Formocresols; Humans; Inactivation, Metabolic; Liver; Metabolic Clearance Rate; Oxidation-Reduction; Pediatric Dentistry; Pulpotomy