endomontreal

      An endodontist case report. Microendodontics case study number: 505026

Twenty five years old patient presenting with an abscessed maxillary molar. Diagnosis: Persisting disease after root canal treatment. Etiology: untreated second mesio vestibular root canal (MB2).

Two appointments were required to preserve that tooth:

First appointment: Crown and post removals plus root canal filling retrieval, MB2 location and calcium hydroxide insertion as a medicament. 

Second appointment: Calcium hydroxide removal, irrigation, drying, final canal obturation gutta percha and Pulp Canal Sealer. Provisional filling material: Cavit.

Abutment is now symptom free and it is now all set for a casted post and permanent crown replacement.

A 6 months follow up dental Xray film shows an impressive  regeneration of periradicular tissues. Compared to its initial size, apical lesion on mesio vestibular root shrunk up to 80%. Tooth is aymptomatic and functional.

A complex root canal retreatment does not have to mean extraction and replacement by a dental implant. A research study by Farzaneh et al. on treatment outcome in endodontic found an orthograde root canal retreatment success rate of 93% . (Farzaneh M., Abitbol S., Friedman S. Treatment outcome in endodontics: The Toronto Study. Phases I and II: Orthograde retreatment. J Endod 2004; 30(9):627-633)

  A new Dental Operative Microscope (D.O.M.) assisted root canal treatment in a calcified maxillary second molar. Case study in microendodontics number: 506317

Radiographic findings: Dystrophic calcifications in the whole canal system are completely obliterating the pulp chamber. It can be expected that the root canal entries are completely embedded in a mass of adherent pulp stones. 

Endodontic procedure problem number one to solve: Locating all four root canal entries without lateraly perforating the root and without destroying to much sound tooth structure in order to keep tooth restorable.

Endodontic procedure problem number two to solve: Cleaning and shaping located root canals without loosing patency, without breaking an endodontic file and without perforating the root. 

Thus, the difficulty level of this endodontic procedure can be considered as very high. A few years back, when there was no surgical operating microscope in our dental practices and only a handfull of daring pioneers in microendodontics, removing this tooth and replacing it  by an implant supported crown would have been a good option to consider in most instances. 

Times have changed. In order to save that tooth, calcified dentin must be carefully removed with long thin ultrasonic tips under the high magnification of dental operating microscope (OPMI PROergo from Carl Zeiss). No rapid technique exists for dealing with calcified root canal system. Root canals has been shaped and  cleaned with Protaper endodontic files and 06, 08,10  K in combination with chelating agent (RC PREP). Canal system has then been filled with Pulp Canal Sealer and Gutta percha laterally and vertically condensed. Provisional filling material: Cavit ^TM.

Endodontic procedure case study number: 449927

To treat such a tooth in endodontics we needed to deal with:

• Difficult access
• Long tooth (24 mm)
• Calcified canals (root canal system with dystrophic calcifications) to locate, shape clean and fill 
• Second mesiovestibular (Mb2) to strive for with the help of a dental operative microscope
• Canal curvature with an "S" form (Bayonet shaped root canal) 

Armamentarium:

PRO Taper endodontic files from Dentsply, OPMI PROergo dental operative microscope from Carl Zeiss, Gutta Percha from META, Pulp Canal Sealer from KERR 

Root canal procedure case study number: 492626 

Patient is having an AAA with a necrotic pulp, an extensive deciduous restoration and a huge tooh decay on distal aspect of this first maxillary molar (Some of us might think: "you don't have to worry it is dead").

Dystrophic calcifications are obliterating the root canal system and we can expect to strive for a second mesiovestibular too. An extreme curvature is also present in distovestibular root canal. 

Prior to the initiation of treatment, an estimate should be made as to the degree of curvature of the canal to be treated. For making this determination merely view the curved canal as having two segments, one extending from the floor of the chamber down the long axis of much of the coronal two thirds of the root and the second from the apex of the root extending back to the occlusal through the apical third of the root. These two lines will intersect and form four angles. The interior angle is the estimate of the degree of the canal curvature. In this specific case, distovestibular root degree of curvature has an estimated 120 degree. Such an estimate is of mesiodistal curvature only and does not take into consideration any buccolingual curvature. The method for making this determination has ben first described by Schneider and then Jungman et al. This present description of Schneider method is from Franklin S. Weine in his book: "Endodontic therapy" Fourth edition pp 314-315

Carl Zeiss Opmi Proergo dental operative microscope was of a big help in locating both mesiovestibular  and distovestibular canals entries, I am using the Pro Taper Endodontic files System from Maillefer for preparation of canals as they are doing very nicely in extremely curved canals. Intracanals treatment procedure is a calcium hydroxide as a medicament (Third x ray from left) since there is a lot of intracanal exudation. Canal filling method: master gutta-percha cone, lateral condensation for the first wave, warm gutta percha for the second wave. Pulp Canal Sealer as the root canal sealer. Amalgam filling has been replaced by a composite filling, because patient wanted to wait a bit for his dental insurance to kick back in. Patients regular dentist will do crowning as soon as possible after that.

Study case number: 482026

Because of an extreme canal stenosis by calcification and because of its obliterated pulp chamber by adherent pulpstones, this first maxillary molar root canal system is not visible on preoperative X ray dental film.

Patient is given full knowledge of the possible risks and benefits of such a complex procedure.  This tooth vestibular cusps are broken, the patient is in pain. She definitly wants to keep her own tooth and give an informed consent. 

Operative field observation is enhanced with high magnification and coaxial xenon lamp illumination (Carl Zeiss OPMI PROergo dental operative microscope). Dystrophic calcifications have been removed from pulp chamber with ultrasonic diamond coated tips. We have been striving to locate all four canal entries (we have been striving a lot more to find MB2 canal entry) and we also had been striving to progressively regain patency by widening each root canal. Lots of chelating agent was needed.  

Our first instruments in the root canals were ISO K Files 06. Canals have then been shaped to K file size 15 and calcium hydroxide inserted. Following appointment allowed us to finish shaping, cleaning and obturation of the root canal system. Root canals have been sealed with Pulp Canal Sealer EWT. 

MB1 and MB2 were not merging at the apex, but both exits were closely juxtaposed. For that reason only a single mesiovestibular root canal shows on post operative X ray dental film. It also appear to be overenlarged but this is not the case.

Knowing that for each uninstrumented millimeter from the apex, a 14% increase in treatment failure might be expected, help of a dental operative microscope in such a case is a no brainer to us. 

Case study number: 486726

Patient was referred to us with a partial pulpectomy in 3 out of four canals. The case came with a note from referring dentist that MB1 was blocked with a calcification. Patient was in pain and was taking an opioïd analgesic prn (Oxycodone) and prn was high. First appointment we needed to take care of the pain issue by completely removing pulp tissue remnants from palatal and distovestibular root canals. Roots are very long and lots of denticles had to be removed from the canal system. Intervention has been done under observation with a dental operative microscope. A mixture of calcium hydroxide and Iodine was then inserted into those canals. This was the only thing that could be done on an emergency basis. Patient had to come back to address the blockage concern in mesio vestibular root canal.

Patient came back 8 days later, symptoms had completely subsided in a mater off hours post op and patient was able to sleep. On second appointment we have been striving to regain patency in MB1 but failed. Then, since a lot of MB1 and MB2 are merging at the apex, we strived to find MB2 canal entry and we did find it. We were hoping to be able to bypass MB1 blockage and seal both canals at once. But blockage was there too, exactly at the same level as in MB1. Root canals have been sealed with Pulp Canal Sealer EWT. Patient has been advised that the mesiovestibular root canals could not be shaped and cleaned to the apex and that for each missed millimeter from the apex a 14% increase in treatment failure might be expected. Both uncleaned canals parts represented a total length of 20 mm. 

This patient is working (as a explosive expert) in a Nickel mine in a very remote area of Northern Canada. Closest dentist is 1000 miles from the exploiting site. He did not want to experiment another blow up of this kind up there, so he decided to come back for a corono apical amalgam, an apicoectomy and a MTA retrofilling on MB1 and 2 before going back to work. Crowning was done by his own dentist. (The very same dentist asked me to do the core build up in amalgam)

Case study number: 434426

Patient was refered to us to locate MB2 and DB canal entries with the help of a dental operative microscope. Calcifications had to be removed with ultrasonic diamond coated tips from the pulpal chamber floor in order to expose those canal entries. 

Endo with difficult access due to tooth position in the arch, calcified, very long (24 mm) and very sharply curved MB and MB2 on second maxillary left molar.

Only high magnification (20X and up)  can help in locating all four canals entries