In a 6-year-old child with a chronically infected primary molar where pulpectomy is not feasible, extraction is the preferred treatment to prevent the spread of infection and preserve the health of the underlying permanent tooth bud. Retaining an infected primary tooth risks chronic infection, pain, and potential damage to developing permanent teeth. Additionally, pulpotomy or indirect pulp capping is contraindicated in cases of chronic infection or necrosis. After extraction, space maintainers may be necessary to prevent malocclusion. Thus, extraction eliminates the source of infection and allows for proper oral development.

Reference: Pediatric Dentistry: Infancy through Adolescence, 6th Edition.