This video shows the obturation of a mandibular second molar that was performed in 2008. It shows the dynamics of the vertical compaction of warmed gutta percha technique very nicely.

Goodman, Schilder, and Aldrich published a 5 part series in the journal Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics (late 70's, early 80's) explaining the complex phase change polymer chemistry of gutta percha (alpha to beta to amorphous). If gutta percha is heated too much (more than a few degrees above body temperature (43.5 C is ideal at the terminus) then there is clinically significant shrinkage. If gutta percha is heated below the temperature that causes an amorphous phase change then the volume of gutta percha slightly expands which enhances the seal.

It is very important to heat and compact in multiple cycles with the deepest pack being 4-6mm from the apical terminus. There are many nuances which idealize the obturation result. It is strongly advised that the viewers take my complete clinical endodontic course so that the important details are not misinterpreted and misapplied. There are many “warm” and “hot” gutta percha filling techniques. All have unique dynamics with differing results. Radiograpy can be misleading and a white dense line on a radiograph does not mean a clean, three-dimensionally filled complex root canal space. No technique is perfect but some are much less than adequate.