endomontreal

Patient was told seven years ago to remove lower right premolar and replace this tooth by an implant supported crown. Lack of periradicular tissues implied a guided tissue regeneration wich, in turn implied a bone curetage close to the mental foramen. Estimated health risk: A possible permanent nerve paresthesia caused by a curetage or by an implant surgery close to the mental foramen on a patient with a narrow crestal mandibular bone. A possible failure of guided tissue regeneration wich in turn, would impair implant osseointegration (or simply make the implant surgery impossible). Clinical examination revealed a mobility level of 2 and a sinus tract. Our findings on radiographic appearance: a large but a localised bony defect and a tooth that needed a root canal retreatment. Our suggestion to the patient: To put aside the implant surgery and to invest in a root canal retreatment with a few Ca(OH)2 replacements. The patient had to be patient (and faithful) for a few months in order to monitor progressive periradicular tissue healing. Results: Per and post operative control X ray films show a progressive, then complete healing of periradicular bone tissue. In this case, root canal retreatment proved to be a safe predictable way of saving that tooth at half the cost of an agressive implant surgery. Now, 7 years later, the tooth has it’s own casted post, a PFM crown and it’s mobility level came back to zero. And above all, patient is now completely safe from any paresthesia risk.

case: 430646

Resorption associated with chronic apical periodontitis altered the shape and position of the foramen through osteoclastic activity, in the x ray images, the modified foramen in distal root is positioned farther from the radiographic apex and gutta percha appears in overextension. A large and circumbscribed radiolucency involves both roots as well as the furcation. This indicates an important periradicular tissues destruction. Tooth mobility level 2 goes along with this tissue loss.

This case is definitly a controversial one, meaning that it is possible for different practitionners to prognosticate endodontic success (very few among practioners) or failure with a great amount of disparity. As stated by John I. Ingles, a senior lecturer in endodontics: "The practicing dentist should not be cited for faulty judgment when even the so-called experts tends to disagree on prognosis… All in all, one must ultimately develop confidence in one's own abilities. Being able to practice using a great variety of techniques and not being "married" to a single approach in every case will greatly enhance one's capabilities. And on this is based good prognosis, the result of skill, knowledge, and self confidence."

Endododontic retreatment and MTA root-end fillings have been performed with a Zeiss Pro Ergo Microscope in september 2008. Last displayed X ray film on this post shows a 3 years post operative clinical outcome. Radiographic examination shows a complete regeneration of the periradicular tissues and a resoptive defect healing. 

Should an implant have been put there? maybe, maybe not!

Read more about MTA Precision placement with the microscope (.pdf)

Case study number: 397137

Tooth history: First attempt of RCT on this mandibular second molar in 2005 did not eliminate symptoms, a second attempt in 2006 did not turned out to be any better, tooth was still having episodes of severe pain (preoperative X ray dental film taken in January 2007). Patient was told by the second practitioner to remove that tooth but she would rather try to save it for the third time. 

Patient was already aware of the tooth poor prognosis and that implant therapy would be the safest way to eliminate symptoms. Still she agreed to retreat the tooth endodontically.

During the procedure, a zip with perforation and apex blunderbuss could be noted on mesial root canals as well as in distal root canal. An apical split (with no existing apical constrictions) was also noted by probing in the distal canal. Serous exsudate was coming out of those root canals in such an amount that it could not be dried even with lots of paper points. Calcium hydroxide was inserted into the canals and patient came back 8 days later. By then symptoms had subsided. After removal of calcium hydroxide into the canals, serous exsudate was still present but in lesser amount. Another attempt with calcium hydroxide replacement was made. Patient came back, symptoms free, 2 weeks later. At this point, almost no exsudate was remaining. All canals, including apical split in distal root, were "plugged" with MTA (Mineral trioxide aggregate) under high magnification. Coronal part of the tooth was sealed with a posterior composite and no promises where made to the patient who decided not to invest in a crown considering the prognosis. This procedure has been achieved in August 2007, the X ray dental film on the right shows a 4 years post operative outcome. Even though circumscribe apical radiolucency is still present the tooth remained symptom free and functional.

In this specific case, MTA used as a root-end filling material proved so far to be effective in promoting regeneration of the original tissues when it is placed in contact with the periradicular tissues. High magnification with excellent coaxial illumination insured a better placement of this material. 

To read more about MTA applications please go to: 

Clinical applications of mineral trioxide aggregate

Mahmoud Torabinejad DMD, MSD, PhD^1,  and Noah Chivian DDS, FICD, FAC²

Study case number: 491047

We have been presented with this previously treated tooth. The canal system has been filled with Sargenti's paste and a separated past filler still remains in mesial canal. Second image displays a mesial root close up with the broken paste filler reaching it's apical third. 

Patient is informed about these facts and is made aware of the tooth poor prognosis if separated instrument cannot be removed and if Sargenti's paste cannot be completely removed from canal system. Extraction and implant therapy is considered but patient wants to keep her own tooth. Informed consent is given by the patient.

Pulp chamber is accessed trough amalgam obturation, filling material is then removed with ultrasonic tips and two canal entries (out of three) are localised. Sargenti's paste is broken into smaller pieces until a softer aspect of the material is found, coronal part of paste filler is exposed and the separated instrument is retrieved and an Xray dental film is taken (Third image). First instrument, a number 06 ISO K file is reaching the apex in fourth X ray image. Fift image is a" calcium hydroxide paste insertion" post operative X ray dental film. Last image (bottom to the right) is a final obturation with Pulp Canal Sealer and gutta percha (lateral and vertical condensation).

This is a case where, based on the X ray image of a "J" type lesion in combination with a deep narrow periodontal probing, one could easily think of a cracked tooth. However, when observing under high magnification, no crack could be seen from within the root canal mesial wall. This J shaped radiolucency was in fact a narrow desmodontal sinus tract originating from an endodontic infection. Saving that tooth implied a retreatment, a ledge bypass and a few calcium hydroxide dressings replacements. As shown on those control post operative X ray images, a slow but complete periradicular tissues regeneration occured. In this case study, even a CBCT 3D imaging would have shown a deep narrow bony defect that could have misled the practionner to conclude the presence of a cracked tooth. Direct observation under a dental operative microscope showed us otherwise, proving once more how micro dentistry is elevating endodontic care to a higher level. 

Case study number 456147

We have been presented with this mandibular second molar that has a periapical lucency which also has a periodontal component. Patient is experiencing pain. This radiographic image also shows a huge radiographic J-shaped lesion that may be indicative of a vertical root fracture in the mesial aspect of the mesial root. 

Are we dealing with a periodontal infection? And, if this is the case, such a periradicular tissues loss would command an extraction of the tooth. 

Are we dealing with a fracture? And, if this is the case, tooth extraction would also be the treatment of choice. 

Are we dealing with an endodontic infection? If this is the case an endodontic revision (endodontic retreatment) would suffice to preserve this tooth. 

The decision of extracting or saving that tooth should be based on a foundation of sound diagnosis.

One of the primary fact that needs to be established in distinguishing endo/perio lesion is the pulp status. Since there is not much pulp left in that case, pulp testing won't help much.

Periodontal probing is the next important measurement in determining if wether this tooth has an endodontic or periodontic infection. Probing shows no wide or narrow pocket on buccal neither on lingual (and on distal) aspects of this tooth, at this stage, periodontal infection might be ruled out.

The remaining question is: "Are we dealing with a fracture or an endodontic infection?" A deep narrow periodontal pocket would indicate a vertical root fracture and the quiz would end right there. The tooth would have to be extracted.The problem is that this defect, if it does exist, might be located just beneath a wide and tight mesial contact point and probing with accuracy this area is not that obvious. Hence the final question cannot be answered without any doubt by probing alone.

One option would be to remove the crown to allow for a direct access to the potential defect. But then, if no deep narrow periodontal pocket exist, the clamp for the rubber dam as well as tooth protection from vertical forces would require a provisional crown to be installed. Even so, probing a deep narrow periodontal pocket is not an absolute waranty that this defect is in deed a crack. It might also be a desmodontal sinus tract. Hence,drilling through the existing crown to access mesials root canals and a direct observation under magnifying lenses of a microscope seemed to be the appropriate way of confirming the presence or absence of a vertical root fracture. 

No crack could be observed from within the mesial root canals, the treatment has been completed in two appointments (third, fourth and fifth images) . Following the first appointment which implied material retrieval, irrigation and calcium hydroxyde insertion (Second X ray image), both pain and swelling disappeared. Following Xray image shows a complete periodontal tissue regeneration after one year. Tooth is asymptomatic.

Case study number 485946

Symptomatic mandibular molar, patient can't chew on that side. Referred to us for endodontic revision.

First appointment intervention steps:

Coronal-radicular access (access through PFM crown, access through coronal build up) taking great care not to perforate the previously weakened pulpal floor, gutta percha removal, locating DB, regaining patency in calcified distal canals to the apex without perforation or deviation, correcting step in apical third of mesiolingual canal, negotiation of mesial canals, CHX 2% irrigation, CHX 2% left in canal system for one minute, drying canals, insertion of calcium hydroxide dressing, provisional obturation (Cavit)

Second appointment intervention steps:

Removal of Ca(OH)2, CHX 2% for one minute, dry canals, cone fit checking and final obturation with Pulp Canal Sealer and Gutta Percha.

Small sealer overflow is a good warrant of apical seal.

Referring dentist is planning a fixed bridge 37, 36, 35 X. (Patient did not want an implant to replace missing #34)

Case study number: 461716

Patient came to our office with spontaneous intermittent pain on maxillary right side. He can readily identify the tooth, he is showing the first molar. Patient is taking many Aspirin tablets per day and is tired of suffering.

Tooth history: first attempt of root canal treatment which ended up with a broken instrument.The patient was then seen two years ago by another practitioner who succeeded in the broken instrument surgical retrieval. Even thought, at the time, a complete retreatment has been performed, the tooth remained sensitive. Since then, painful episodes became more and more frequent with a growing pain intensity. 

Tooth is sensitive to palpation with a mobility of level 2. A new crown is protecting the cusps and occlusion looks fine. Pre operative Xray shows an apical periodontitis on mesio vestibular root and something that might be a perforation with a bunch of wispy gutta percha points into it. Patient is informed of this concern prior to starting anything. Patient is informed of the high incidence rate of a fourth canal in those first maxillary molars (Studies shows up to a whopping 92% rate). He is also made aware that this fourth canal may have been omitted. After the exam, patient knows that at least two concerns have to be addressed in order to solve his problem. Implant is suggested but patient is reluctant, he is 25 years old and he wants to keep his real tooth. 

The two first X Rays are preoperative

Third X rays show the recovered MB2 with a first instrument (number 08 ISO file) reaching its apex, the fourth X ray film shows the repaired perforation with MTA and intracanal medication (Ca(OH)2 dressing) in MB2. 

Fifth image shows immediate post operative outcome with the Pulp Canal sealer overfill which has no impact on the overall prognosis. An amalgam has been placed as a long term provisional for one year. Symptoms subsided almost immediately after the intra canal dressing. The monitored tooth has been fine all along for one year. The last Xray is a one year post operative control with a brand new crown in place.

Access made through crown makes the treatment much more difficult in that the landmarks that direct the clinician to the pulp chamber are removed. Our microscope integrated video camera recorded a short movie showing treated MB2 and the MTA repair, the position of the repaired perforation site (dark grey shade) in relation to the real position of the MB2, clearly stresses out what can happen while you are looking for the MB2 with external contour of the tooth being altered by a PFM crown. 

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. 

Tooth presenting an "against all odds" clinical situation , many would think: "you don't have to worry it is dead!". Dental operative microscope allows the practitioner to  let it be something he tried his damnedest on.