1. Endodontic Retreatment
A Chance to Rewrite History
My plan for this evening [morning] is to give an overview of the information that was covered in the newsletter. I’ll also include my own cases and perspectives.
As we proceed, please feel free to interrupt me if you have questions. And, of course, I’ll be happy to answer questions after the presentation.

2. Up to 40 million endodontic cases treated annually in USA
Endodontic treatment is never a guaranteed success. In fact, it is estimated that roughly 10 percent of endodontic treatments fail. Unfortunately, with as many as 40 million endodontic cases treated in the U.S. each year, the number of failed treatments can be overwhelming! What does this mean to you and me? Well, for one thing, it means that we need to look into what causes endodontic treatment to fail and what we can do to improve the chances of success with the initial treatment. But it also means that we need to know more about retreatment and how, hopefully, we can help patients save their natural teeth.

3. treatments fail. In fact, it is estimated that
roughly 10 percent of endodontic
treatments fail.
this number of failed treatments can be overwhelming!
What does this mean to you ?

4. It means that we need to look into what causes endodontic treatment to fail.
and what we can do to improve the chances of success with the initial treatment.
we need to know more about retreatment and how, hopefully, we can help patients save their natural teeth.

5. Prognosis Prognosis is a key word
It refers to the prediction of success or failure in a given situation

6. @ development of more rationale TX methods.
The advantages of understanding the prognosis for RC procedures Include:
@ development of more rationale TX methods.
@ avoidance of factors that increases failure rate,
@and a better understanding of the healing process

7. Factors Influencing Success & Failure
Some of the factors that influence outcome are:
The presence of apical pathosis
Extension of obturation (short or long )
Quality and technique of obturation
Type of intracanal medication
Bacterial status of the canal before obturation
Observation period

8. When to Evaluate Suggested follow-up periods range from
6 months to 4 years
● probably 6 months is a reasonable evaluation period for the first recall and 4 years for the final
evaluation( while keeping in mind that failure may
occur many years later).

9. Methods of Evaluation Clinical Examination Radiographic Examination
Histologic Examination

10. Clinical Examination Clinical criteria for success include :
Absence of pain and swelling
2. Disappearance of sinus tract.
No loss of function
No evidence of soft tissue destruction, including probing defect.

11. Radiographic Finding
According to the findings, each case is classified as
Success,
failure, or
questionable

12. Success Is indicated by the absence of a radiographic apical lesion.
This means that a lesion present at the time of treatment has resolved or
that a lesion not present at the time of treatment has
Not developed.

13. Failure is the persistence or development or development of radiographically evident pathosis.
Specifically, this is a radiolucent lesion that
has Enlarged,
has Persisted, or
has Developed since the TX

14. Questionable indicates a state of uncertainty
Questionable indicates a state of uncertainty. The radiolucent lesion has neither become worse nor significantly improved.

15. What are the common causes of endo failure:
Leaking res
Root fractures
Untreated canals
Inadequately cleaned canals
Procedural errors
There are a number of common causes for endodontic failure. Among these are faulty restorations, coronal leakage, root fractures, untreated canals, inadequately cleaned canals, and operative errors, such as errors in placing posts, separated instruments, blocks, ledges, perforations, and transportations. We need to keep these problems in mind as we perform root canal treatment. No two patients are alike, and therefore no two canals are alike. Care should be taken in each case to make sure that no potential problem is overlooked.
As I mentioned earlier, even with a seemingly successful treatment, problems can arise months or even years after treatment. When this occurs, we need to examine the situation and then determine the best course of action.

16. Procedural errors, such as
errors in placing posts,
broken instruments,
perforations, blocks, ledges,

17. We need to keep these problems in mind as we perform root canal treatment.
No two patients are alike,
and therefore no two canals are alike.

18. Even with a seemingly successful treatment, problems can arise months or even years after treatment. When this occurs, we need to examine the situation and then determine the best
course of
action.

19. When should retreatment be considered
When should retreatment be considered ? When is it time to endodontically retreat a tooth ?
When is it time to endodontically retreat a tooth? That depends on a variety of circumstances. Retreatment may not always be necessary or even possible. It is up to you to assess each patient’s unique situation and determine the treatment that will provide the best outcome for the patient. Biological, clinical, esthetic, functional, and financial factors must be considered.

20. That depends on a variety of circumstances...
 Retreatment may not always be necessary or even possible.
 It is up to you to assess each patient’s unique situation and determine the treatment that will provide the best outcome for the patient.
 Biological, clinical, esthetic, functional, and financial factors must be considered.

21. Is retreatment possible for this case ????????????????

22. What do we have to evaluate before embarking upon Retreatment ?

23. A .Evaluate periodontal status
Periapical/bitewing
Attachment apparatus
Periodontal probing
Mobility
Crown-to-root ratio
You should begin by evaluating the status of the periodontal tissues surrounding the tooth. The ability to distinguish between an endodontic problem and a periodontal problem is of the utmost importance. If retreatment of the tooth is considered, you should first take periapical and bitewing radiographs. This will allow you to evaluate the status of the root, crown, and attachment apparatus. If there is a sinus tract, it should be traced to the source of origin using a flexible probe, such as a gutta-percha cone. Assess periodontal status by taking periodontal probings and examining mobility and crown-to-root ratios. When taking periodontal probings, look for a narrow, deep pocket, which can indicate vertical root fracture. Each of these factors can affect the success of the retreatment procedure.

24. The ability to distinguish between an endodontic problem and a periodontal problem is of the utmost importance.

25. If retreatment of the tooth is considered, you should first take periapical and bitewing radiographs. to evaluate the status of the root, crown, and PDT.
If there is a sinus tract, it should be traced to the source of origin using a a gutta-percha cone.

26. Assess periodontal status by taking periodontal probings and examining mobility and crown-to-root ratios.
When taking periodontal probings, look for a narrow, deep pocket, which can indicate vertical root fracture.

27. B. Evaluate tooth restorability
Remaining tooth structure
Strategic value
Next, evaluate the restorability of the tooth. Retreatment should be chosen because it is the best option available. Because the natural tooth is better than a replacement, an attempt at retreating a tooth should be made unless the outlook is questionable.
There are several factors to be considered. Is the periodontal support adequate? What is the strategic value of the tooth? Is it a front tooth that is important esthetically? Will the tooth be a bridge abutment? Is it a molar that is an important part of the patient’s occlusion? You must also consider the stability of the tooth structure. Has too much dentin been destroyed during previous endodontic treatment or by caries or fracture? Is there at least 2 millimeters of sound tooth structure above the depth of the sulcus on which to place the crown? If not, the crown and/or post and core will eventually fail. Is crown lengthening surgery required? If so, what are the cost factors? The esthetic concerns? All of these factors are important in determining the restorability of the tooth.

28. There are several factors affecting the restorability:
Is the periodontal support adequate?
What is the strategic value of the tooth?
Will the tooth be a bridge abutment?
Is it a front tooth that is important esthetically?
Is it a molar that is an important part of the patient’s occlusion?

29. You must also consider the stability of the tooth structure:
Has too much dentin been destroyed during previous endodontic treatment or by caries or fracture?
Is there at least 2 millimeters of sound tooth structure above the depth of the sulcus on which to place the crown?
If not, the crown and/or post and core will eventually fail.
Is crown lengthening surgery required? If so,
what are the cost factors?
what are the esthetic concerns?

30. C. Consider impact of retreatment
Consider the impact that retreatment will have on the overall treatment plan. Is the prognosis reasonable?
If this was your tooth, would you have it retreated, given a similar set of circumstances?
Remember, however, that the tooth and the treatment decision ultimately belong to the patient.

31. D. Assess patient concerns
Expectations
Motivation
Cost
As with all forms of treatment, it is important to assess the patient’s concerns. Will the patient be happy with the results of the treatment? Does the patient value his or her dental health enough that he or she will follow treatment with a timely restoration? If not, it may not be worth considering retreatment as an option. It is also important to determine if the results will justify the expense.

32. As with all forms of treatment, it is important to assess the patient’s concerns.
Will the patient be happy with the results of the treatment?
Does the patient value his or her dental health enough that he or she will follow treatment with a timely restoration?
If not, it may not be worth considering retreatment as an option.
It is also important to determine if the results will justify the expense.

33. Retreatment often involves other problems as well — problems that aren’t seen in initial endodontic treatments.
These problems include separated instruments, perforations, ledges, and obstructions such as resins/cements, posts, and calcification.
Can you handle any problem that might arise during retreatment?
Do you have the latest technologies that will help you to achieve the best possible outcome?
Have you had sufficient experience in successful retreatment to give the patient the best possible prognosis?

34. Most importantly, before you make the decision to retreat a tooth endodontically:
you must present the facts objectively to the patient.
Explain the diagnosis and discuss the different treatment options that are available, explaining the pros and cons of each option.
Help the patient to determine which option is best for him or her.

35. Most importantly, before you make the decision to retreat a tooth endodontically:
You don’t want to give the patient false hope that retreatment is going to be a simple procedure, and you definitely don’t want to guarantee success.
Keep in mind that you should always anticipate the worst case scenario.
The key is to be honest and present all the facts. Your patient will thank you for it later!

36. Treatment Options Nonsurgical retreatment vs. Surgical intervention vs
Treatment Options Nonsurgical retreatment vs. Surgical intervention vs. Extraction
While periodontal status, tooth restorability, patient concerns, and practice productivity are all very important in the decision to retreat, perhaps the most important thing to consider is what strategy will offer the best prognosis. You already know that something must be done about the tooth. Now you must decide whether to nonsurgically retreat it, to surgically intervene, to consider both treatment options, or to extract the tooth. What procedure will produce the best outcome?

37. the most important thing to consider is what strategy will offer the best prognosis.
You already know that something must be done about the tooth. Now you must decide:
whether to nonsurgically retreat it,
to surgically retreat it,
to consider both treatment options, or
to extract the tooth.
What procedure will produce the best outcome?

38. Nonsurgical retreatment is performed because:
It is the Best option
It Reduces need for surgery
It Improves prognosis for future surgery
In most cases, nonsurgical retreatment is performed to reduce the need for surgery or to increase the prognosis for a future surgery, so nonsurgical retreatment, when possible, is obviously the treatment of choice. And with the latest advances in technology — including magnification, illumination, ultrasonics, apex locators, rotary instrumentation, variably tapered shaping instruments, contemporary filling techniques, and devices to remove intracanal obstructions — non-surgical treatment is often possible and highly successful.

39. Extraction because of Nonrestorability Guarded periodontal prognosis
Vertical root fracture
Sometimes, neither endodontic retreatment nor surgery offers a reasonable prognosis. For example, surgery may be contraindicated due to the patient’s compromised health, although extraction can often be more traumatic. Sometimes the tooth may not be restorable, or the procedural errors in the initial treatment cannot be repaired. A guarded periodontal prognosis is another factor which would often lead to extraction. And a split tooth or a tooth with a vertical root fracture would almost always need to be extracted. Again, these factors do not always warrant extraction, and each case needs to be evaluated individually.
Let’s examine a few cases.

40. Case Study #1 Previously treated with post Apical resorption
Severe decay
Post perforation
Not retreatable
Logical option is Extraction
In case #1, we have a 47-year-old woman with a previously endodontically treated tooth. The tooth serves as an anterior abutment for a failing fixed bridge. The radiograph shows apical resorption and significant decay under the anterior abutment.
What would you do in this case? Clearly the tooth cannot be retreated endodontically. The logical option is extraction of the tooth. Let’s look at another case.

41. Case Study #2 Significant decay Crown leakage Symptoms
In Case #2, we have a 42-year-old man who cannot chew due to the pain in the first mandibular molar. There is significant decay under the distal margin of the crown which is evidence of coronal leakage. Radiolucencies are evident and the crown needs to be removed. You can see from the radiograph that the mesial roots contain silver cones and the distal root is filled with a gutta-percha cone.
How would you treat this case?

42. Case Study #2 Crown removed Filling materials removed
Retreated entirely
New amalgam core
This case was treated by dismantling the crown and removing the filling materials. The tooth was retreated entirely and a new amalgam core was placed.

43. Restoration removal
Disassembling restorations has been facilitated by advances in technology, including ultrasonic, crown and bridge removers, and instruments to loosen and remove posts.
But removing the restoration isn’t always possible
As in Case #2, when non-surgical retreatment is chosen as the best treatment option, restoration removal is the first step. It is a step that can tell you a lot about the case. Once the restoration is removed, you may be able to identify what caused the initial procedure to fail — caries, restoration failures, fractures, untreated canals, blockages, ledges, and perforations. Determining the causes of previous failure can help you to be more successful with the retreatment procedure.
Disassembling restorations has been facilitated by advances in technology, including ultrasonics, crown and bridge removers, and instruments to loosen and remove posts. But removing the restoration isn’t always possible.

47. Once the restoration is removed,
you may be able to identify what caused the initial procedure to fail — caries, restoration failures, fractures, untreated canals, blockages, ledges, and perforations.
Determining the causes of previous failure can help you to
be more successful with the retreatment procedure.

48. Restoration removal alternatives
If you can not remove restoration consider:
Retreatment through the crown
Surgical treatment
Sometimes the restoration should be left in place because of the cost of replacing a complex restoration, patient comfort, dental function, or esthetics. If you determine that the restoration should not be removed, it may be necessary to retreat the tooth through the existing crown or restoration. By leaving the restoration in place, you can often access the root canals through it, and remove the post/cores and filling materials and successfully retreat the tooth. If this is not an option, you must prepare for surgical treatment.

49. Sometimes the restoration should be left in place because of the
cost of replacing a complex restoration,
patient comfort,
dental function,
or esthetics.

50. If the option to keep the existing restoration, you must prepare for surgical treatment.

51. If the option is : Remove the restoration
Then we should consider, removal of:
The crown
The post
The obturation material
When removing a post, consider the length, diameter and direction of the post, as well as the cementing agent used, if that can be determined. Note the design of the post, whether it is threaded, tapered, or cast. Each of these will affect how the post is removed.

52. Removing gutta-percha
Rotary Files ( D1, D2,D3)
Heat
Ultrasonics
Solvents chloroform
Any combination of these
Gutta-percha can be removed using any combination of rotary instruments, heat, ultrasonics, or solvents. The best technique depends on the shape of the canal, the quality of the obturation, and whether or not objects, such as broken instruments, are present. Gutta-percha is fairly easy to remove using a combination of these techniques.

58. Why this root canal failed???

60. Three carrier-based obturators were removed from this lower molar
Three carrier-based obturators were removed from this lower molar. Then, the root canal system was thoroughly recleaned, reshaped, and obturated. Healing of the apical radiolucency was observed at a six-month recall examination, shown in the bottom radiograph.

62. Removing paste
The fourth type of obturation material that might be encountered is paste. Practitioners may encounter two types of paste — white eugenol-based paste, which is usually soft and penetrable within the canal, and reddish-brown resin-based paste, which is brick-hard and extremely difficult to remove. Solvents are available for many types of paste to aid in their removal, but it is important to identify which type of paste has been used so that you can select the appropriate solvent.

63. Retreatment of paste filling
was done
through
the existing
restoration

65. Thank you!
If you have further questions, I’ll be happy to talk with you after the meeting, and I do have (extra copies of the newsletter, business cards, referral slips, etc.) for anyone who is interested in more information. Thank you for your time and attention. You’ve been a wonderful audience.