Histopathology of radiolucent furcation lesions associated with pulpotomy-treated primary molars.

The purpose of this project was to characterize the histopathology of radiolucent furcation lesions associated with primary molars which had received pulpotomy treatment. Twenty-four pulpotomy-treated primary molars which displayed radiolucent lesions in the root furcation suggesting unsuccessful outcome were extracted. Pretreatment radiographs were available for 6 teeth and none had evidence of a furcation radiolucency. These 6 teeth were treated with a standard formocresol pulpotomy and restored. The pretreatmen t condition and the pulpotomy procedure employed for the remaining 18 teeth is unknown. If a lesion remained attached to the root, it was transferred to 10% neutral buffered formalin. The sockets were gently curetted and the tissue transferred to fixative. Specimens were processed and stained for microscopic examination. Histological examination of the lesions revealed granulomatous, chronic proliferative, and acute inflammation and epithelium. Three specimens were diagnosed as furcation granulomas. Stratified squamous epithelium was observed in 21 specimens which were diagnosed as either a furcation granuloma with epithelium or a furcation cyst if an epitheliallined lumen was present. Pulpotomy-treated primary molars should receive periodic postoperative radiographic examination and be extracted if a furcation lesion develops. A pulpotomy is the standard treatment for vital primary teeth with carious pulp exposures (Troutman et al. 1982; McDonald and Avery 1983). The subsequent degeneration of the treated radicular pulp tissue may lead to failure of the pulpotomy (Rolling et al. 1976; Rolling 1978; Magnusson 1978). A furcation radiolucency associated with a pulpotomized primary molar is a sign of failure of the pulpotomy treatment (Rolling and Lambjerg-Hansen 1978; Magnusson 1978). Limited information is available to characterize the radiolucent lesions associated with unsuccessful pulpotomy treatment. However, cystic lesions have been reported following pulpotomy treatment of primary molars with formocresol, or phenol-containing compounds (Grundy and Adkins 1984; Savage et al. 1986). The histopathology of furcation lesions associated with cariously exposed primary teeth has been described (Lustmann and Shear 1985; Myers et al. 1987). These lesions are mixed inflammatory reactions with the chronic granulomatous inflammatory reaction being the predominant type observed. These lesions may contain epithelium suggesting the potential for cystic transformation. The purpose of this project was to characterize the histopathology of radiolucent furcation lesions associated with primary molars which had previously received pulpotomy treatment.