TRANSPORTATIONS
Q. What are apical transportations?
A. An apical transportation of the root canal represents iatrogenically moving the physiologic terminus to a new location on the external root surface. In many instances, these canals become wet with exudates and difficult to dry. Transportations lead to post-operative flare-ups, surgeries and extractions. A canal that has been apically transported predisposes to obturation overextension where gutta percha moves beyond the foramen and into the periapical tissues. Consequently, the canal is vertically overextended, but importantly, laterally underfilled which contributes to leakage, bacterial infection and failure.
A. An apical transportation of the root canal represents iatrogenically moving the physiologic terminus to a new location on the external root surface. In many instances, these canals become wet with exudates and difficult to dry. Transportations lead to post-operative flare-ups, surgeries and extractions. A canal that has been apically transported predisposes to obturation overextension where gutta percha moves beyond the foramen and into the periapical tissues. Consequently, the canal is vertically overextended, but importantly, laterally underfilled which contributes to leakage, bacterial infection and failure.
Q. What is the best approach to managing a transportation?
A. Managing transportations requires optimal preparation of the coronal two-thirds of the canal prior to placing ProRoot (Dentsply Tulsa Dental) into that portion of the canal that exhibits reverse apical architecture. ProRoot is easy to use and the powder is mixed with anesthetic solution or sterile water to a heavy cake-like consistency. A small aliquot of this cement is picked-up and introduced into the prepared canal with a microtube carrying device such as a customized spinal tap needle, on the side of a West Perf Repair Instrument (SybronEndo), or a Dovgan carrier (Quality Aspirators). ProRoot is then gently tamped and coaxed down the canal to approximate length using an apically trimmed customized nonstandard gutta percha cone as a flexible plugger. ProRoot can also be vibrated, moved into the defect and to length, around root curvatures, with the EndoActivator (Dentsply Tulsa Dental) or, in straighter canals, with the ProUltra ENDO Tip #3, 4 or 5 (Dentsply Tulsa Dental). Direct sonic or ultrasonic energy will vibrate and generate a wave-like motion which facilitates moving and adapting the cement into the apical extent of the canal. Prior to initiating subsequent procedures, a dense 4-5 mm zone of ProRoot in the apical one-third of the canal should be confirmed radiographically.
Q. Should a transportation be managed any differently when it is apical to a canal curvature?
A. In the instance of repairing a defect apical to the canal curvature, a 4-5 mm column of ProRoot is first shepherded around the curvature with a flexible gutta percha plugger. A precurved 15 or 20 stainless steel file is then carried around the canal curvature, into the ProRoot and to within 1-2 mm of the working length. Indirect ultrasonics with a ProUltra Endo Tip #1 is then utilized on the shaft of the file. This vibratory energy will encourage ProRoot to slump, move and adapt to the configurations of the canal laterally as well as control its movement to and gently against the periapical tissues. Alternatively, the EndoActivator may be utilized in these instances as its sonically-driven, polymer tips can work effectively and safely around root curvatures. Again, the clinician should radiographically confirm that there is a dense 4-5 mm zone of ProRoot in the apical extent of the canal.
Q. Do you have a tape series on how to use MTA? I love the material, but have trouble with placement. Have you come up with a solution to this problem?
A. MTA, commercially known as ProRoot, may be carried into the field with various devices. A relatively new device that has come to market is the Dovgan carrier (Quality Aspirators) which I have found particularly useful in placing ProRoot. In addition, the Ruddle on Retreatment DVD entitled "Management of: Blocks, Ledges, Transportations & Perforations" has an excellent section on the mixing and handling of ProRoot.