From: C. John Munce
To: ROOTS
Sent: Saturday, July 29, 2006 5:14 AM
Subject: Yesterday's Deep Troughing Case

Again, this case involved deep troughing with narrow-shafted 34mm-long tiny round burs until the MB2 was identified
mid-root.  The lengths of the MB1 & MB2 canals were 20mm and 19.5mm, respectively, from the MB cusp tip, so the troughing
depth was about 13-14mm.  When clarifying M canals of maxillary or mandibular molars, it is quite possible to work very
deeply with these burs by using them primarily in a bucco-lingual sweeping motion and working into the bulk of root
structure--away from the furcal wall, decreasing in bur diameter while progressing apically.  If you're not afraid to
lay the mesial wall of the access cavity toward the mesial either with slow speed round burs or with HS diamonds,
it can be quite surprising what amount of curvature can be "overcome" deep within a root when necessary for access to
a separated instrument, for example........  [This case is not intended as an example of that principle.]  cjm.






Broken file remouve using ProUltra ultrasonics and Mueller burs.

Tooth was obturated with RF cement and has a pinky colour.
Using Solvent like Endosolv R diamond coated ultrasonics and Mueller burs for troughing i`ve exposed the broken file
and remouved it with Pro Ultra.

Don`t have discovery burs in Russia...well maybe in future... Ivan Vyuchnov









Nice work getting out that sep'd instrmnt and excavating to the end of the RF Cement--Mueller burs work well so long
as you have a bulky root--as in your case--because they only go down to approx a #2 bur tip size.  They also have a
flexible shaft which is counterproductive for deep exploration cases--better to have stiff shafts for positive control - cjm.