From the perspective of anthropology, situational learning theory has its core characteristics and elements, practice community is the carrier of knowledge, learning is achieved through legitimate peripheral participation, the whole learning process is understood as cultural absorption and fusion, and ultimately achieve the transformation of identity in community.

We provide a new vision for teachers\' practical knowledge management by explaining legitimate peripheral participations\' concept and its nature,and make reasonable analysis of internal needs and external constitute.

Comparison of marginal fitness for non-precious metal-ceramic crowns of different marginal types;

AIM:To study the effect of infiltration speed on the marginal fitness of In-Ceram alumina base.

Comparison of marginal adaptation of metal crown with different dental casting alloys;

Comparison of the marginal adaptation of metal crown with different wax pattern materials;

Marginal adaptation of crown by national CAD/CAM;

Objective To evaluate the marginal adaptation of four based dental alloys.

Study on marginal fit of all-porcelain labial margin of porcelain fused to metal crown with cement;