Endodontic Retreatment & MTA Preserve the Tooth

Here's a tooth that had endodontic treatment over 10 years ago. While the clinician had difficulty finding all the canals, the tooth has been functional for quite some time. A large furcal defect raises suspicion of a root fracture or perforation.

DX: Prior RCT w/ Symptomatic Apical Periodontitis.

There are many who would consider this hopeless and recommend extraction.

Let us consider the cause of this treatment failure:

1. Missed Canals

2. Furcal Perforation or Root Fracture?

Can these issues be addressed to preserve the natural tooth?

In my consultation with the patient, I explain these issues and that endodontic re-treatment may be able to save the tooth (as long as the root is not fractured). I also explain the alternative option of extraction.

Finding missing canals is a simple solution.

A perforated root can be repaired with guarded prognosis.

A fractured root will require extraction.

I tell the patient the only way to know for sure is to open the tooth and investigate. Considering the nice crown on the tooth, the cost of attempting to save the tooth is minimal, compared to the cost of removing and replacing. In this case the patient elected re-treatment.

Pre-operative radiograph.

Upon access, 2 additional canals are located and instrumented. A furcal perforation is also identified. No root fractures are found.

Re-treatment is complete. Canals obturated with gutta percha and furcal perforation repaired with MTA. Glass ionomer base is placed over MTA.

7 month recall shows a tooth that is fully functional with remarkable healing of the furcal defect. Endodontic re-treatment has preserved the natural tooth.

Dens in Dente

Dens in Dente literally means "a tooth within a tooth". It is a developmental anomaly caused by an epithelial invagination during the development of the tooth. Enamel is laid down on the internal surface of the tooth. This is most frequently seen in maxillary lateral incisors.

A thin layer of enamel can be seen internally. An amalgam restoration was previously placed at some point to try and seal off the development groove into the dens in dente.

Access for endodontic treatment reveals the internal layer of enamel.

Endodontic treatment is completed.


This peg lateral incisor also shows the internal and external layers of enamel of a dens in dente. The large dens in dente has also affected the overall development of the tooth.
Submitted by: Dr. Rico D. Short of Smyrna, GA.

Apexification with Calcium Hydroxide & MTA Fill

This 15 year old patient has a history of trauma to #8. Trauma occurred at an age before apical closure occurred. Tooth was diagnosed with necrotic pulp and symptomatic apical periodontitis. Note the large periapical lesion.

Traditional apexification using Ca(OH)2 was used.

Tooth debrided to the apex, NaOCl irrigation.

Ca(OH)2 placed.

3 month check shows resorption of Ca(OH)2, but apex still open. Apical lesion almost completely healed.

Ca(OH)2 placed again.

10 month re-evaluation. Apical barrier present, so it was time to obturate. This is a great view of the apical barrier that has formed.

Tooth was obturated with MTA. If this tooth ever needs apical treatment, a simple resection will be done without retropreparation or retrofilling.

Removing a Broken Endodontic File

Anyone performing endodontics occasionally has a separated instrument. This case was referred for removal of a separated instrument.

The file is in the MB#2 canal. Since it is in the upper third of the canal, good visualization with a microscope and proper ultrasonic technique will make this file removal possible.

After finding the file, careful ultrasonic instrumention is used to remove dentin around the file - opening up the MB groove. This is done carefully without touching the file itself. We want to expose 2-3 mm of the file before we begin vibrating the file itself.

Too much contact with the file in this early stage can cause a coronal piece of the file to break off, making it more difficult.

Once the coronal coronal 2-3mm of the file has been accessed, the ultrasonic is placed on the most apical part of the file to begin vibrating it. This should loosen the file and vibrate it out. If the file breaks again, then repeat step one.

The file was removed and the MB#2 canal instrumented.

Removal of the separated instrument complete.

Use of an operating microscope is essential in effective removal of a separated instrument.

Lichen Planus - A Review

Lichen planus is a fairly common condition that affects the oral mucosa. This idiopathic condition is believed to be an immunologically mediated.

The name likely comes from the appearance of the lesion which resembles that of a lichen. A lichen is a symbiotic organism composed of an algae and fungi.

There are medications that may induce a reaction in the oral mucosa that appears like the idiopathic form of lichen planus. The medication induced form of the this condition is referred to as "lichenoid mucositis" or "lichenoid dermatitis".

Lichen planus can cause skin lesions as well as oral lesions. Skin lesions are usually purple, pruritic, polygonal papules. Skin papules may exhibit Wickham's straie (lacelike network of white lines).

Oral lesions may be reticular or erosive.

Reticular lichen planus is most common. It usually causes no symptoms. Wickham's straie are seen throughout. The lesions may "wax and wane" over time. It is commonly seen in the buccal mucosa, but also seen in the tongue, gingiva, palate and vermillion border.

Appearance of reticular lichen planus in oral mucosa.

Erosive lichen planus is more symptomatic. It appears as atrophic, erythematous areas with ulceration. White straie are also seen in the periphery of the lesions.

Diagnosis can usually be made on clinical findings alone.

No treatment is usually recommended for reticular lichen planus. Antifungal therapy can be helpful if a candidiasis infection occurs.

Erosive lichen planus is usually treated symptomatically with topical corticosteroids and frequent follow up care.

The malignant potential of lichen planus has not been resolved. If the possibility for malignant transformation exists, it appears to be small and associated with erosive lichen planus.

Interlacing white lines, known as Wickham's straie are the characteristic feature of lichen planus.

(Source: Neville, Damm, Allen, Bouquot. Oral & Maxillofacial Pathology, 680-685, 2002.)

Saving the Natural Tooth with Intentional Reimplantation

Intentional reimplantation is the intentional removal (extraction) and reimplantation of a tooth. This technique can be useful for teeth that cannot be treated with traditional endodontic surgery. This strategy can be particularly helpful in lower second molars where proximity to the mandibular nerve and thickness of the buccal bone make endodontic surgery difficult.


This patient presented for treatment of tooth #18. It had previous endodontic treatment 15 years earlier. The patient presented with some intraoral swelling and intermittent pain that was worsened with pressure and biting. Class II mobility and deep buccal probing were found along with the obvious periapical radiolucency and apical resorption. The tooth was diagnosed as: Prior RCT with chronic apical abscess. The large access cavity weakening the mesial tooth surface was noted and discussed as well as the possibility of a root fracture.

Treatment options discussed included:
1. Retreatment and look for fracture
2. Apicoectomy and look for fracture
3. Intentional reimplantation and look for fracture
4. Extraction

Due to the conical root structure, closeness to the mandibular canal, and probable root fracture, we decided to perform and intentional reimplantation.
Tooth was removed atraumatically and no root fractures were found.

Immediate root resection, retropreparation and retrofill with MTA was performed.
Patient was given PenVK 500mg for 5 days.
Patient was informed of the guarded prognosis following this procedure. Long term follow up will be required to determine the success.

6 year recall of the patient finds the tooth completely functional and asymptomatic. While there are many who would not have considered saving this tooth, the intentional reimplantation procedure has saved this patient thousands of dollars and allowed him to retain his natural tooth.

Strengthening the future of endodontics

In the May 2009 issue of the Journal of Endodontics (JOE) two very important topics have been addressed that are shedding light on what the future of endodontists may look like.
One of the articles is : Update on Imbalanced Distribution of Endodontists: 1995-2006, by H. Barry Waldman and George A. Bruder.
The other, is the letter from AAE president Dr. Louis Rossman addressing the issue of ”Super generalist”.
Before I get into the importance of these two articles, let me point out some very important facts that have changed the economics of dentistry in the USA.
A) In the past 40 years the caries rate has dramatically gone down which has resulted in less number of patients requiring dental treatment due to less number of carious teeth.
B) At the same time, more dentists are practicing longer and opting for delayed retirement.

C) Today’s ratio of dentists to population is 58 per 100,000 which is very high compared to golden age of dentistry in 1960-70s, when this ratio was 49 per 100,000.

D) Today there is an oversupply of dentists in the USA. The areas where there is a shortage, namely the rural areas and the inner-cities, have been chronically underserved, and less than 5 % of graduating dental students have shown an interest practicing in these areas, over the years.( Refer to many articles published in the Journal of Dental Education). [Unfortunately ADA has not taken a strong leadership position on this issue, and I do not see any foreseeable action on their part regarding the oversupply of dentists in the USA. The article “Future of Dentistry” published in the JADA Vol.133,Sep 2002 , 1226-1235, calls this oversupply problem, “maldistribution of dentists.” The problem here is that no entity can make these dentist move from supersaturated metro areas to rural and inner-city area where there is a shortage thus oversupply of dentist in USA will not go away for years to come. ]

E) The student loan debt for an average graduating dental student has tripled in the past 15 years, to $ 180,000. ( 2006 statistics)

F) Dental insurance companies are taking advantage of these oversupply trends, by reducing reimbursement rates per procedure, further eroding the profits for dentists.

G) Three new dental schools have opened in the past 3 years, one in California, and two in Arizona, adding to the number of dentist coming into the marketplace.

As a result of the above, there has been a significant and growing economic pressure on the general dentistry market over the past 20 years causing erosion of profits and decrease in “busyness”, which will continue for years to come.

Which brings me back to the two articles in May 2009 issue of JOE.
Based on the above facts, it is obvious why we are seeing more and more “Super generalists”. The general dentists are under pressure to keep whatever comes in, in-house, and are tempted to do procedures they are not well trained for, to make money and pay their office overhead, student loans and make some profit.

That is why we are seeing an explosion of “retreat-odontics” by endodontists, re-treatment of failed implants by periodontists, re-dos of botched full mouth reconstruction by prosthodontist and more lawsuits and state dental board actions, all emanating from the “hungry general dentist syndrome.”
With all this happening on the general dentistry side, it is obvious that all specialists, including endodontists are negatively impacted. Less referrals are made to us, and when the referral is made, it is a retreatment of a case that is already problematic, or maybe beyond help, requiring extraction.
(This explains why some endodontists are getting into implant therapy.)

The other article by Waldman and Bruder, highlights the problem that we endodontists need to address or face financial and clinical extinction in the next 10 years.
A 48.5% increase in the number of endodontist in the USA from 1995-2006 is recipe for disaster, considering the facts discussed above, along with the emerging “super-generalist” phenomenon.

In my opinion these should be some of the steps, we as endodontists must take to correct this emerging threat:


1) Reduce the number of endodontic residency positions immediately.
( This step was taken by the dermatology residency programs in early 1990s. As a result of that bold move more than a decade ago, today dermatologists are prospering and there is no oversupply of them nationwide.) Some chairpersons can do this now without any pressure from dental school deans or administration, and they need to act now.
The others who are under pressure not to do this, can raise the money that the dental school will lose from reducing the number of residents, from their past endodontic alumni.
2) Accept residents with a minimum of 5 years general dentistry practice experience after graduation from dental school. (Today’s cases referred to an endodontist, are very complex and require a good knowledge of endo, perio and restorative treatment.)

3) Make teaching at a dental school for 12 days a year (which could be once a month per year, or 12 days in a row or any other combination of days, as long as it is 12 days a year) a mandatory requirement for Diplomate status re-certification. This will address the endodontist shortage in the faculty at dental schools and increase exposure of the undergraduate students to endodontists. Endodontics should not be taught by general dentists to undergrad students.

4) Get involved in teaching the general dentists, by discussing cases they should, and cases they should not do.

Action is needed and is needed urgently. Otherwise one day we will look back and will be forced to admit that “We have met the enemy and he is us.”

I welcome your comments,
Robert Salehrabi, DDS

Loss of Tooth Structure - by Mark Montana DDS

This week's Inner Space Seminar, sponsored by Superstition Springs Endodontics, was presented by Dr. Mark Montana. Dr. Montana is a highly recognized prosthodontist practicing out of Tempe, AZ.

Dr. Montana's presentation reviewed the many causes of loss of tooth structure including: attrition, abrasion, ablation, abfraction, caries & erosion. Recognition of the etiology is paramount to proper treatment planning and long term success.

In the following video excerpt, Dr. Montana discusses the multifactorial etiology that is commonly associated with the loss of tooth structure.




Dr. Montana talked about bruxism and how that diagnosis is often misused as a "catch all" to describe loss of tooth structure. The following video excerpt is a case presentation of a patient with severe bruxism.



The following additional excerpts are available:

Attrition

Corrosion/Erosion

Mark S. Montana DDS

2147 E. Southern Ave.

Tempe, AZ 85282

480 820-2901

Resorption of Calcium Hydroxide Paste

Calcium Hydroxide is widely used in endodontics for a number of purposes. Its antimicrobial properties are attributed to its high pH (basic), destructive effects on bacterial cell walls and ability to dissolve organic tissue. It is used routinely as an intracanal medicament. It is also used for apexification, apexigenesis, treatment of root resorption.

Ca(OH)2 used in endodontics is made with Ca(OH)2 powder, a vehicle and a radiopacifier. Most common radiopacifiers are barium sulfate, bismuth or compounds containing iodine or bromine. While radiopacifiers make the calcium hydroxide more visible radiographically, some radiopacifiers are known to resorb at a slower pace, sometimes making it difficult to see the subtle changes.

While the control of a paste material at the apex of a canal can be very difficult, the resorptive properties of calcium hydroxide make it a very forgiving material. Extrusion of calcium hydroxide past the apex of a tooth is not uncommon. In fact, there are some who would recommend deliberate extrusion in the case of a large, chronic periapical lesion to help in the healing of such a lesion.



Calcium hydroxide (Ultracal - Ultradent - 35% Ca(OH)2 with barium sulfate) was used during treatment of this tooth to control exudate prior to obturation. A significant amount was extruded past the apex in close approximation to the maxillary sinuses during the endodontic treatment.




14 months later, the patient returned for treatment of #14. Our recall radiograph of #15 shows complete resorption of Ca(OH)2. The patient had no complaints and is in full function.



Sources:

Hasan Orucoglu, Funda Kont Cobankara, "Effect of Unintentionally Extruded Calcium Hydroxide Paste Including Barium Sulfate as a Radiopaquing Agent in Treatment of Teeth with Periapical Lesions: Report of a Case", Journal of Endodontics, July 2008 (Vol. 34, Issue 7, Pages 888-891)

The Evolution of Implant Success

The 7th Annual Spring into Dentistry seminar was held on March 6th, 2009 in Mesa, AZ. The guest lecturer was Dr. Robert London of Seattle, Washington. Dr. London is currently a clinical professor and director of graduate periodontics at the University of Washington. Prior to his work at UW, Dr. London was director of graduate periodontics at NOVA Southeastern and at University of Southern California.
Dr. London's presentation was entitled, "Enhancing Dental Outcomes".

While a good portion of his presentation had to do with implant treatment planning and preparation of implant sites, he made some comments that I found fascinating.

He used an analogy of a pendulum to describe the acceptance of dental implants into mainstream dentistry. Early on, there was some resistance to accepting them into everyday practice. Like the swinging of a pendulum, treatment with dental implants then became the solution to every situation. Now that the pendulum has swung to both extremes, we are now hopefully settling somewhere in the middle.

He also discussed the changing definition of success with implants. Early on, successful implant therapy meant osseointegration. If the implant was not loose, it was considered a success. In endodontics, success has always been defined very strictly as the complete resolution of signs and symptoms and complete healing of bone. With two such different definitions of success, it is no wonder that there has been misinterpretation regarding the treatment outcomes of the two different treatments.

Dr. London pointed out that what was once considered a successful implant (osseointegration alone) may no longer be an acceptable treatment outcome. Successful implant therapy now requires getting the implant to integrate in the right position, where it can support a prosthesis and look like a natural tooth. This is a major difference from simple osseointegration.

Dr. London stressed how important it was to have an interdisciplinary approach to dental treatment so all specialties are included in the best treatment approach for each patient.

We were pleased to have Dr. London come and share some of his expertise regarding periodontal bone grafting and implant treatment. We hope that the balanced approach to endodontics and implants which he described continues to gain momentum.