The use of mass spectrophotometry to detect resorcinol–formaldehyde-induced discoloration and resorption of primary teeth

Resorcinol–formaldehyde (RF) has been known to cause red stains in the permanent teeth. While the use of this material in permanent teeth is controversial, there is little known about the effects of RF resin on primary teeth. A 6-year-old male and 9-year-old female (siblings) presented with a complaint of discoloration and mobility of the primary molars. On clinical examination, the teeth showed red discoloration as well as stains around restorations placed on them. Periapical radiographs revealed a radiolucency surrounding the affected teeth. On extraction, it was observed that the red discoloration extended to the tooth surface. Hematoxylin and eosin staining was done on two decalcified extracted teeth while two specimens (one from each patient) were subjected to gas chromatography–mass spectrometry (GC-MS) system (TRACE™ Ultra, Thermo Fisher Scientific, Waltham MA, USA). Histological examination showed signs of coagulative necrosis, while the GC-MS examination revealed the presence of a resorcinol spike confirming the initial diagnosis of RF therapy. The affected teeth were extracted and a long-span band and loop space maintainer placed in the younger child. The older child was observed for the eruption of the permanent tooth. RF resin can result in the discoloration and early exfoliation of primary teeth. This case report highlights the risks of using RF therapy in primary teeth.