Periodontal Tissue Formation by Reaggregation System in Mice

Abstract

The reaggregation system is a special technique developed to clarify the essential characteristics of the mesenchyme. In this study, the reaggregation system was performed using mouse lower first molar at E13.5 and the reaggregated tooth germs were transplanted into the kidney capsule for 6 weeks to investigate tooth root formation. The reaggregated tooth was surrounded by bone. The reaggregated tooth germ produced a single thick root like a taurodontium (cuneiform tooth), although mouse lower first molar has two roots in vivo. Histologically, the reaggregated mesenchyme could form not only tooth elements including enamel, dentin, dental pulp and cementum, but also periodontal tissue including periodontal ligament-like structure and alveolar bone-like structure. The periodontal ligament-like structure has a regular width between the cementum and alveolar bone-like structure. Moreover, Sharpy's fiber-like structure was inserted into the cementum and alveolar bone-like structure. In conclusion, the reaggregated mesenchyme has the ability to form both tooth and periodontal tissue without information from the epithelium. In addition, this reaggregation system may be a useful method for regenerative dentistry, since tooth and periodontal tissue can be produced en bloc.