Then & Now 


 Where Are We Now ?

Where is the profession of endodontics, and where do we reside?

Change brings advancement and change brings growth.

Several areas of interest that maintain a focus with our clinical endodontic patient care include:

  • Longevity (life span)
  • Fracture
  • Microleakage
  • Bone loss patterns
  • One of the most important issues that often requires vigilance to assess is survival versus success (related to post-operative sensitivity, tenderness, discomfort or pain)


Nonsurgical Care:

Internal Chamber and Internal Radicular Instrumentation inside teeth only

(Commonly known as root canal treatment)

Surgical Care

External Instrumentation at Root/Bone Interface in bone & around apical field

(Commonly referred to as apicoectomy or retrofill)

Combined Care

Nonsurgical and Surgical Care (combined)


Keeping Careful Watch for Difficulties


Survival Versus Success

Wide opinion exists empirically and academically, through practice and research, regarding success rates of endodontics.

Some may purport low success rates while others report incredibly high success rates.  Somewhere in the middle is probably a better assessment of success, although providing a percentage number is difficult due to so many variables that uniquely present with each patient case, study or type of practice.

It has been my experience after delivering ample patient care, seeing others’ results, and hearing others’ testimonies, that patients do indeed have ongoing sensitivity, tenderness or even discomfort after endodontic therapy.

Dr. Gordon Christensen made a statement confirming that many teeth were a problem and had sensitivity after endodontic therapy in the past. He recently cited success rates…and it is my opinion that his viewpoint on endodontics has some merit.

This brings us to an understanding that we could all be more vigilant in the acceptance and scrutiny of patient outcomes.  We all have clinical failures at times.   Also, we all experience endodontic therapy after which the patient says their tooth still feels hollow, sensitive, tender or painful.

How do we define survival versus success or failure after endodontic therapy is rendered?

In clinical practice, we can consider that teeth have been successfully treated if they are very comfortable and/or have no residual symptoms. On the other hand, survival could be looked at as it relates to teeth that still are symptomatic (residually mild or perhaps tolerable but temperate).

Therefore, understanding the difference between survival and success requires more vigilance.   A surviving tooth leads to frustration for future treatment planning. Is this tender or sensitive tooth that the patient complains of going to settle down or continue to ail or fail after root canal treatment occurred?

A “surviving” tooth may lead to frustration for the patient and doctor while the patient continues to  experience sensitivity, tenderness or discomfort.  We may allow the course to progress (letting the patient restore their tooth and accept their level of symptoms as success in our own minds), while survival may indeed be a better assignment to the patient’s clinical outcome.

But does survival convert to failure?

The problem we face is, “How do we know if a surviving case is going to become successful and ‘settle down’, or if it is going to progress to a delayed failure in the short, intermediate or longer term?”  And what can we do about it?

If we adopt a more vigilant attitude, it is easy to see that rendering nonsurgical care with surgical care on the same clinical visit, does indeed improve outcomes.  Utilizing combined care, we are seeing higher success rates in the aftermath.

Treating teeth endodontically internally as well as providing basic “apical field clearing” by “brush cut or graze cutting of the apical region with conservative apicoectomy” and/or “full” apicoectomy…patient outcomes have shown significant improvement.

Stubborn apical lesions are removed, invisible lesions or inflammation at apex are removed, teeth are denervated better, furcation issues are identified and decided upon, bone loss patterns are better assessed, external fractures as well as resorptions are seen, blocks/transports/ ledges/ rips/ instrument separations and  calcifications can be readily treated with a retrograde approach.  In other words, internal exploration and external exploration with treatment allows for a more certain understanding of the patient’s presentation; and issues can be addressed orthograde or retrograde. This, therefore, is more likely to yield clinical “success” rather than just ‘”survival”.

However, occasional failures (albeit fewer) are going to occur even with combined care; but success will outweigh survival when a combined approach to care is employed.  By offering “combined” care, internal and external root fractures are seen sooner rather than later, apical lesions/microbes are cleared better, infections/inflammations resolve better, resorptions can be diagnosed sooner, and extensive bone or furcal periontal issues can be identified sooner.

Additionally, occult caries can be seen and restorative difficulties can be corrected with combined care that cannot be corrected on “first pass”, if only nonsurgical endodontic care is employed.  Furthermore, un-negotiable canals (for whatever reason) can be addressed, rather than taking a “dismiss/wait-watch/and re-evaluate approach.”

Most important, if a failure does occur following a combined approach to patient care, then we know we have tried most methods available and can make better future decisions about  potentially down-spiraling care or unnecessary diagnostic three-dimensional imaging, and shift directly towards pre-implant care if indicated.

That said, instrumenting teeth internally and externally indeed leads to higher success rates, since occult and obvious problems are addressed.  Simply clearing the apical field has been one of the most relevant changes I have seen in terms of improving patient outcomes (shifting towards success and away from survival).

Assessing healing outcomes and success becomes difficult when a plethora of variables exist.  When we read editorials from clinicians who tout high success rates in their own practices or read other literatures that discuss astronomical success rate percentages with endodontic outcomes, we should pause and rethink all of the variables that perhaps are not being considered.

How long did the study follow patients?  What methods were employed to assess healing or success?  One doctor may say or think that the pain the patient is experiencing is “all in their head”, and convince themselves that the care they rendered is indeed successful; while another doctor may consider it to be only survival.

Vigilance is key to recognizing the subjective nature and idiosyncrasies we all employ to judge the care we delivered as successful.  In the post-care phase, if the patient “feels it”, are they surviving or do we have success?

Cone beam tomography (“CAT Scan”) will likely redefine many issues in many facets of dentistry, including endodontic success.  It will likely redefine success related to healing studies (though radiographic periapical healing and success as judged by symptoms are two separate entities).

Three dimensional analysis is showing, and will likely continue to show, the occult issues that are missed by employing only nonsurgical care, such as: periapically associated antral thickening mucositis (that could have readily been removed with conservative apical field clearing), missed canals, some fractures, occult and obvious lesions being missed by nonsurgical care and/or missed by two dimensional imaging, transportation/iatrogenesis, etc.

However, simple exploration and basic surgical apical field clearing during the same visit would lessen many problems we face and lessen the “want” for this new paradigm we are seeing emerge with three dimensional imaging for endodontic diagnostic assessment.

Cone beam CT scanning may continue to prove useful in endodontics, although minimizing patient exposure to this modality of radiation would occur less often if basic combined care was provided.

Intuitively, if we miss fewer problems by taking a combined approach to care and maximize our chances for success, then the questionable and perplexing issues with survival or failure occurring would be minimized.



Utilizing orifice barriers has proved useful.  If we analyze obturation we understand its shortcomings. Longevity (life span issues) has seen definite improvement in our hands by offering orifice barriers (whether resin, MTA or other).

Utilizing a material to help prevent microbial/fluid ingress other than gutta percha can be demonstrated as helpful by realizing that fewer short, intermediate or delayed failures are happening with patient care.   Placing a suborifice barrier below the level of where the outside periodontal bone level is located, has seemingly demonstrated improvement.

The reason may be because the extraradicular immune system and blood supply is likely intact below the crestal bone periodontal level, and thus may serve as the natural defense against inward root leakage.  For that reason, we try to have the orifice barrier placed below the level of the outside crestal bone.

In other words, since teeth do experience root leakage above the crestal bone level, and gutta percha notoriously leaks, we strive to place canal suborifice barrier materials at a level apical of the lowest external crestal bone area in attempt to maximize seal and improve outcomes in terms of longevity.

An additional change currently in progress, is reducing the suborifice pre-flare entry diameter to see if less root fractures occur.  Noteworthy, at the orifice and 1-3 mm suborifice, conserving dentin width for strength while balancing the need for access, to be able to instrument canals and place cement barriers, has become an ongoing assessment with outcomes, so far.

In other words, the diameter with machining of the orifice, along with the depth apically, we place and pack the suborifice barrier materials…this is an ongoing assessment.


In Closing

Studies vary regarding success rates from various literature references.  Recently, Dr. Gordon Christensen has made a second statement regarding endodontic post-operative sensitivity, while citing a recent reference that reports what I support – success rates in a range of 80%.

Hence, we should continue to find ways to improve outcomes and minimize ongoing patient discomfort by recognizing that “nonsurgical only” care does indeed have shortcomings.  Recognizing the shortcomings with performing only root canal treatment or retreatment, and realizing that our colleagues are starting to recognize and talk more openly about these issues…it makes sense to want to implement change, whether with praise or criticism.

We want patients to heal and have the highest chance for success (with one visit if possible).  Of all the technical approaches taken to find ways of improving success, clearing the apical field has demonstrated the highest improvement in outcomes.  Finding ways to maximize success and increase longevity are at the heart of endodontic patient care.