What is the difference between paintless dent repair and body filler?

I-CAR describes paintless dent repair (PDR) as "the art of removing panel dents by either pushing or pulling the metal without damaging the finish."

Access to the back of the panel without cutting holes. I-CAR guidance says "do not drill access holes," and that if holes must be cut to reach the back, PDR "is not an acceptable option." Repair guidance, not a law.

I-CAR says glue pull repair "finds its origins in PDR," is typically successful on most panel dents, and is harder on small dents.

A 1996 trade article says PDR suits paint that is not broken. Newer, flexible paint is likelier to move back without cracking, while cracked paint has to be primed and painted, so PDR does not fit it. The same article says some dents stretch the metal too far, and that dents on a rolled edge or a sharp crease usually do. These points are general, from an old article.

A 2000 trade article describes body filler as a paste that brings bent metal back to its contour. The area is then prepared and refinished. The article says filler must be applied properly: thin layers over a clean, sanded surface, because filler that is too thick or poorly prepared can cause pinholes or peeling.

Neither is better in every case. The choice depends on the dent's size, depth and place on the panel, whether the back can be reached without cutting holes, whether the paint is intact, whether the metal is creased or stretched, the automaker's repair procedure, and the shop's methods.

• Is the paint on my dent intact, and does that change the method?
• Is the metal creased or stretched?
• Can the back be reached without cutting holes?
• If paintless does not fit, which panels get painted?
• Why was this method chosen for each dent?