Hall technology and conventional PMC technology: Progress and remaining challenge in extensive caries treatment.

Preformed metal crown restoration technology is widely used in the treatment of large area caries of deciduous molars, which can not only restore the tooth shape but also restore the chewing function of children. Preformed mental crown restoration technology includes conventional preformed mental crown technology and Hall technology. In this paper, the application scope, clinical curative effect, and research progress of clinical-related problems of premolar metal crown in large area caries of children were summarized.