Border molding according to glossary of prosthodontic terms is defined as the shaping of border areas of an impression material by functional or manual manipulation of the soft tissue adjacent to the borders to duplicate the contour and size of the vestibule.
Border molding is an important step in fabrication of dentures as accurate border molding will ensure in the production of an accurate final impression.
There are many techniques and materials that can be employed in border molding. However, it can be agreed on that no single technique or material is superior, as any material is valuable provided it is skillfully utilized.
This revised HD video is about border molding for complete dentures using modelling compound. It includes a discussion of anatomical considerations and tips for improving technique.