Young Bui

Case 1

A 39-year-old male was referred to our office for evaluation of tooth #2.  The x ray (Figure 1) showed the beginning of a lucency at the apex of the mesio-buccal (MB) root.  The restoration was shallow, with plenty of dentin separating it from the pulp.  There was evidence of perio bone loss on the distal side of the tooth.  The patient complained of having episodes of dull aching pain over a two-week period.  He had pain to percussion but not palpation.  He had no sensitivity to cold on the buccal, only on the palatal side.  The first thought that came to my mind was a fracture in the tooth.   When you have a partial non-vital tooth with a shallow restoration, more than likely there is a fracture in the tooth somewhere that caused the tooth to die.  Upon opening up the access, I did not find any fracture line.  There was no decay underneath the restoration.  The pulp tissues in the mesio-buccal and disto-buccal (DB) canals were non-vital.  The palatal (P) root had the entire pulp tissue still intact and vital.  My interesting finding occurred when I was taking the working length measurement with the apex locator.  Both the MB and P roots were 22 mm long.  The reading for the DB root, however, was at 16 mm.  I verified it with an x-ray film.  Apparently, the DB root ended just above the level of the bone.  Bacteria in the saliva must have contaminated the canal, causing retrograde necrosis of the DB root, which in turn infected the MB root.  You can truly appreciate my finding in the final x ray (Figure 2).
 

FIGURE 1: showing the beginning of a lucency at the apex of the mesio-buccal (MB) root.	FIGURE 2: showing the DB root ending just above the level of the bone.

Case 2

An African-American male in his 30s was referred for RCT on tooth #29.  The patient was asymptomatic.  The pulp was exposed upon excavation by the general dentist.  The x ray (Figure 3) shows two distinct roots on this tooth which in itself is pretty rare.  Upon instrumentation of the buccal canal, I was able to locate another canal about 3-4 mm apically from the buccal orifice.  This is normally the case with multiple-root bicuspids.  I have done three maxillary bicuspids with three roots.  In all of the cases, the third canal was located in the buccal root about 2-3 mm apically from the orifice.  Filling such a root is a little challenging.  First, coat the walls of all the canals with RC cement.  The next step is to fill the third canal first.  Then sear it off and remove the gutta percha down to the opening of the third canal, exposing the main buccal canal.  Now you will have an unobstructive path to fill the main buccal canal and the palatal or lingual canal.  You can see the two canals bifurcated almost one-third of the way down the root in Figure 4.
 

FIGURE 3: showing two distinct roots on tooth #29.	FIGURE 4: showing the two canals bifurcated almost one-third of the way down the root.

Case 3

A 38-year-old female presented to the office with constant throbbing pain in her lower left jaw.  Tooth #18 had had RCT done a year ago.  She had pain to percussion and palpation.  The x ray (Figure 5) showed perio breakdown in the furcation and periapical lucency on the MB root.  The tooth had a ++ mobility.  When I saw the perio breakdown in the furcation, the first thing that came to my mind was a strip perforation.  It could also possibly have been a lateral canal, but in this case the gutta percha was situated too close to the furcation, indicating a possible strip perforation.  I proceeded to remove the old gutta percha and cleaned both roots.  When I went in to dry the MB canal, I noticed some blotches of blood on the paper point, confirming the strip perforation diagnosis.  I did not know where the perforation was located along the root so I decided to fill the entire canal with MTA.  (See “MTA: An Excellent Concrete Material.”)  By plugging and laterally spreading the MTA, I was able to force the MTA against the wall and out of the perforation site.  I than went down the canal with the brown EZ-Fill® SafeSider™ file (25/.08 taper) to make a canal space for the gutta percha.  Finally, I filled the canal up with gutta percha and EZ-Fill® cement.  You can see the puff of MTA extruding into the furcation through the perforation site in Figure 6.  It will allow bone to grow around it without causing any inflammation.  You can see the furcation beginning to heal up in the 3-month follow-up x ray (Figure 7).  The tooth is asymptomatic and the mobility has disappeared. 
 

FIGURE 5: showing perio breakdown in the furcation and periapical lucency on the MB root.	FIGURE 6: showing the puff of MTA extruding into the furcation through the perforation site.

FIGURE 7: the 3-month follow-up x ray.