Endodontics Treatment outcome

TREATMENT OUTCOME

Objectives

Q1 - What is meant by the outcome of endodontic treatment?

Q2 - How do you classify the outcome of endodontic treatment?

Q3 - What factors influence the outcome of root canal treatment and retreatment?

Q4 - What factors influence the outcome of surgical endodontics?

Q5 - How do you assess the outcome of endodontic treatment?

Q6 - Why are the reported outcomes diverse?

الفشل و النجاح بتاع المثل

االندو و الجراحه بين مقارنه

Mayan Cosmetic Dentist

Scott Rice, Jewel Inlays by the Cosmetic Dentists of the Maya, ricedentistry (949) 238-6745;2014

Progressive development of apical scar. This permanent artifact frequently follows through and-through osseous destruction of both labial and palatal cortical plates. A Before cyst enucleation. B, Six months following surgery. C, One year following surgery. D, Two years following surgery; scar is permanent. E, A similar nonpathologic radiolucent area was removed and examined; it is filled with fibrous connective tissue, no inflammatory cells.

(A-D, Photos courtesy of Or M. Krasnoff; E, Photos courtesy of Dr. S,N. Bhaskar)


Success and Failure

Success rate of different studies

Subjective terms, Ambiguous Terms

from the clinician’s point of view,

this endodontic treatment has clearly not been a success.

Case:


An endodontically treated tooth

symptom free and functional, with sinus tract and periapical radiolucency which is increasing in size,

The patient not experiencing symptoms and can use their tooth,

patient may call it,

SUCCESS

The Principles of Endodontics, By Shanon Patel, Justin J. Barnes


1-No Symptoms. 2-No Clinical Signs Of Disease3-No Periapical Radiolucency

Endodontic treatment to be deemed a success.

This is the ideal

However, it may be unrealistic to achieve in all cases.

immediate post-operative radiograph showing a periapical

radiolucency

one year later showing full

resolution of the periapical

radiolucency

Strict/ Stringent criteria:

- no symptoms, - no clinical signs of disease, - a decrease ( or at least no increase)

in the size of the preoperative periapical radiolucency

The Principles of Endodontics, By Shanon Patel, Justin J. Barnes

loose/lenient criteria:

This is a more realistic approach

- especially as it is currently not possible to sterilize the entire Root canal system so that it is microbe-free


endodontic treatment to be deemed a success.

(a) immediate post – operative radiography:

(b) radiograph taken one year later showing a reduction in size of the periapical radiolucency .

patient being asymptomatic and able to use the endodontically treated tooth. “it doesn’t take into account whether periapical periodontitis has been cured or prevented following endodontic treatment.

Asymptomatic functional tooth “Functional retention”:

Similar to the dental implant assessment criteria


• Clinical normalcy with or without a persistent radiolucency, decreased or unchanged.

A- C, Mandibular first molar with apical periodontitis, associated with gingival recession, probing depth beyond the apex, and extensive bone loss on the buccal aspect. The patient was advised of poor prognosis, but decided to proceed with treatment in an attempt to retain the tooth in function as long as possible. D, E, Completed root canal treatment and application of a resorbable guided tissue regeneration membrane. F, G, At 6 months, the radiolucency has been considerably decreased and the gingival tissue appears healthy, Although the prognosis remains poor, the patient's goal has been achieved. Replacement of the defective crown has been deferred by the patient.

(Friedman 2002. )


“Functional retention”

Effective, Ineffective

Current guidelines published by the European Society of Endodontology

Healed, Healing, Diseased

Healing, Disease, and Function – Clear Terms

Success is generally defined as ‘the accomplishment of an aim or purpose’ (Oxford Dictionary).

The outcome, is best defined in direct relation to the specific aim.

In the Endodontic ttt, the aim is to eradicate the disease and allow healing.

Accordingly, in order to promote effective communication within the profession and with patients, the outcome of Endodontic Treatment should be related to ‘healing’

A combined clinical (no signs and symptoms) and radiographic (no residual radiolucency) normalcy. Included in this classification is the strictly defined, typical appearance of a scar.

Friedman 2002


- Healed:

A, Maxillary second molar with apical periodontitis extending along the mesial root surface, and associated sinus tract (traced with a gutta-percha cone)

B, Completed treatment. C, At 1 year, the radiolucency is completely resolved and the tooth is symptom free, indicating the lesion has healed.

Reduced radiolucency combined with clinical normalcy, in follow-up periods shorter than 4 years. This is consistent with the strict definition of ‘uncertain’ healing.

Friedman 2002.

- Healing (in progress):


A, Three prefabricated posts in mandibular molar with post treatment disease,

B, Access was prepared through the crown and posts were removed: canals were dressed with calcium hydroxide

C, Completed root canal re-treatment.

D, At 6 months, the lesion is reduced and the tooth is symptom free, indicating that healing is in progress.

- Persistence of radiolucency (an expression of apical periodontitis) with or without clinical signs and symptoms ,

- presence of symptoms even when the radiographic appearance is normal.

Friedman 2002.

Persistent disease “diseased”:


A, Immediate post operative radiograph of maxillary second molar with no evidence of apical periodontitis.

B, Emerged disease at 3 years. C, Further expansion of disease at 6 years. In spite of the presence of disease, the tooth is symptom free.

Q2:How do you classify the outcome of endodontic treatment?

•Patient symptom free•The endodonticaly treated tooth is functional•Clinically: The associated tissues are healthy •Radiographicaly: the associated periapical tissue appear healthy or there is evidence of healing by scare tissue formation.

Clinical evidence of a favorable outcome associated with a mandibular lateral incisor tooth (a) preoperative sinus tract; (b) the sinus tract healed one year later


1-Criteria for a favorable outcome

•Patient may be complaining from symptoms or symptoms free•Clinicaly: may be low grade tenderness to palpation or percussion•Radiographically: periapical radiolucency has persisted (remind the same size or only reduced in size) within the four year assessment period

Radiographic evidence of an uncertain outcome associated with maxillary central incisor tooth


2-Criteria for uncertain outcome

(a) immediate post operative radiography

(b) radiograph taken one year later shows no change in the size of the periapical radiolucency

•The patient is complaining of symptoms “pain , swelling”.•The endodontically treated tooth not functional “the patient avoid eating on the tooth due to aggravation of symptoms”•Clinically: there are signs of infection, eg sinus tract, swelling.•Radiographically:-A new periapical radiolucency has developed post-treatment.-the periapical radiolucency has increased in size post treatment- the periapical radiolucency has persisted (remained the same size or only reduced in size) at or after a four year assessment period.

Radiographic evidence of an unfavorable outcome associated with a maxillary first molar tooth


3-Criteria for an unfavorable outcome:

(a) immediate post-operative radiograph

(b) radiograph taken one year shows an increase in the size of the periapical radiolucency (yellow arrow)

Favorable, Uncertain, Unfavorable


Diagram summarizing the review process (Adapted from guidelines published by the European society of endodontology)


Q3:What factors influence the outcome of root canal treatment and retreatment?

Factors that influence the outcome:-Preoperative statues of the periapical tissue.- Quality of the root canal filling-Quality of the coronal restoration.

Factors that may influence outcome:-Medical statues of the patient. -Preoperative sinus tract statues.-Experience of the clinician.- Use of rubber dam.- Type of files used for preparation.- Type of irrigant used.- Number of visits complete treatment.- Type of medicaments used- Type of root canal filling used- Technique used to fill the root canal.

Factors that have no influence outcome:-Gender of patient- Age of patient-Type of tooth


Factors that influence the outcome

The outcome of endodontic treatment is more likely to be favorable in:-teeth with vital pulps - teeth with inflamed pulps(e.g. irreversible pulpitis)-Teeth with necrotic uninfected pulps. 95%

Radiographically: these teeth would not have signs of preoperative periapical radiolucency.

In teeth with signs of periapical periodontitis (i.e. periapical radiolucency on radiography) the probability of achieving a favorable outcome (i.e. curing an existing periapical periodontitis) after endodontic treatment is in the region of 85 percent.

This is likely to be due to teeth affected by periapical

periodontitis having a more established infection in the root canal system when compared to teeth

unaffected by periapical periodontitis.

1-Preoperative status of the periapical tissue:

85 %


The literature has conflicting conclusions on the influence of the size of the preoperative periapical lesion

on outcome of treatment.

The likelihood of a favorable outcome appears to be higher when the size of the preoperative periapical lesion is small

(<5mm).


2-Quality of root canal filling:

Favorable outcome is lower when:-the root canal filling is overextended “long”.Microbes and infected debris are extruded into the periapical tissue.

Overextended root canal fillings and associated periapical radiolucency.

It’s not necessary due to the overextended root canal filling material itself.

Q3:What factor treatment s influence the outcome of root canal and retreatment?

- The root canal filling is underextended “short”. This is because the portion of the root canal which does contain any filling material is likely to contain residual microbes due to inadequate mechanical and chemical preparation.

Underextended root canal fillings with visible patent root canal space apically and associated periapical radiolucencies


-This is because spaces within the root canal filling may allow periapical tissue fluid to enter the root canal and provide a nutrient of any residual microbes, a place for any residual microbes to multiply. Passage of microbes and their toxins from the root canal space into the periapical tissue.

Voids within root canal filling and associated periapical radiolucencies

The root canal filling contain voids.


3-Quality of the coronal restoration:A satisfactory of the coronal restoration has no marginal deficiencies, defects, or recurrent caries. Defects on the coronal restoration present routes for reinfection of the root canal space from the mouth.

Unsatisfactory quality root canal fillings and coronal restorations, and associated periapical radiolucencies


Factors that may influence outcome


Body’s ability to heal periapical periodontitis may be impaired in certain medical conditions.” Poorly controlled diabetes, immunosuppressant medication”.

-Medical status of the patient:


May indicate a higher number or virulence of endodontic microbes. There is some evidence to suggest that the probability of achieving a favorable outcome is higher with no preoperative sinus tract.

-Sinus tract: Q3:What factors influence the outcome of

root canal treatment and retreatment?

Ng Y-L, Mann V, Gulabivala K. A prospective study of the factors affecting outcomes of nonsurgical root canal treatment: part 1: periapical health. International Endodontic Journal.

General dental practitioner versus specialist in endodontics.

-Experience of the clinician


-Using of rubber dam:

Failure to use rubber dam has been shown to influence the choice of root canal irrigant, has a negative impact on treatment outcome and places the patient at risk of swallowing or aspirating materials and instruments.

Ahmad IA1, Rubber dam usage for endodontic treatment: a review. Int Endod J, 42(11):963-72 2009


Shanon Patel, Justin J. Barnes: stainless steel versus nickel titanium (NiTi), there are many benefits to using niti file systems to prepare root canals, (reduce mechanical preparation time, less clinician fatigue, however there is insufficient data to show that a particular type of file will achieve a higher outcome of endodontic treatment.

-Type of files used for preparation


Gary S.P. Cheung, and Christopher S.Y. 2009 :Concluded that There was a higher incidence of procedural errors and a lower success rate for primary root canal treatment of teeth prepared with stainless steel files compared with the use of NiTi instruments in a continuous reaming action

Gary S.P. Cheung, and Christopher S.Y. , A Retrospective Study of Endodontic Treatment Outcome between Nickel-Titanium Rotary and Stainless Steel Hand Filing Techniques, J Endod 35:938–943, 2009

The Principles of Endodontics By Shanon Patel, Justin J. Barnes

irrigants which are antimicrobial and can dissolve organic materials has better outcome “sodium hypochlorite (NaOCl) is the gold standard irrigant.

-Type of irrigant used:


New research suggest that there is no significant difference in the outcome between single and multiple visit treatment.

-Number of visits to complete treatment:


Sathorn et al 2005:stated that single-visit root canal treatment appeared to be slightly more effective than multiple visit, i.e. 6.3% higher healing rate. However, the difference in healing rate between these two treatment regimens was not statistically significant (P ¼ 0.3809).

C. Sathorn, P. Parashos & H. H. Messer, Effectiveness of single- versus multiple-visit endodontic treatment of teeth with apical periodontitis: a systematic review and meta-analysis, International Endodontic Journal, 38, 347–355, 2005

no solid evidence to support one type of medicament over than another in term of increasing the probability of achieving a favorable outcome.

-Type of inter-appointment medicament:

Gutta-Percha (GP), Polymer based materials, calcium silicate cements, in the 1990s there was a flurry of literature purporting that GP leaked and polymer based materials were more likely to seal the root canal system, the methodology and clinical relevance of these mainly laboratory based studies has been criticized, presently, there is insufficient data to suggest that one type of root canal filling material significantly increases the probability of achieving favorable outcome.

-Type of root canal filing material used: Q3:What factors influence the outcome of

root canal treatment and retreatment?

cold compaction, warm compaction, there are many pros and cons to the various root canal filling technique.

-Technique used to fill the root canal system:


Chu CH, Lo ECM & Cheung GSP. Outcome of root canal treatment using Thermafil and cold lateral condensation filling techniques. International Endodontic Journal, 38, 179–185, 2005

Q4: What factors influence the outcome of surgical endodontics?

Outcome of surgical endodontics more likely to be favorable when using:-Contemporary surgical equipment (micro-surgical instruments, operating microscope, endoscope.


Contemporary techniques : resecting the root end without bevel, using ultrasonic tips to prepare the root end cavity's.


Contemporary materials: MTA ,IRM, EBA, G.P.


Q5 - How do you assess the outcome of endodontic treatment?

The most accurate way to examine the periapical area after endodontic treatment by block dissection and serial histological sections of the tooth and the surrounding jaw bone

Q5:How do you assess the outcome of endodontic treatment?

-Which is replaced by :

1-Assessment of the patient symptoms 2-Clinical examination 3-Radiographic examination

WHICH IS IMPOSSIBLE…!!!

(a) immediate post-operative radiograph;

(b) radiograph taken one year later shows bony infill

Radiographic Outcome AssessmentAssessment of radiographic images has been shown to be highly inconsistent. The consistency of assessment can be significantly improved when structured observer and calibration strategies are applied, as suggested for endodontic treatment.

Goldman M, Pearson AH, Darzenta N. Reliability of radiographic interpretations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1974:38:287-93

Q5:How do you assess the outcome of endodontic treatment?

(b) radiograph taken 1 year after treatment showing no periapical radiolucences.

Patel S, Wilson R, Dawood A, Foschi F, Mannocci F (2012) the detection of periapical pathosis using digital periapical radiography and cone beam computed tomography – Part 2: a 1- year post treatment follow-up, international endodontic journal, 45,711-23,

(c) reformatted cone beam computed tomography (CBCT) images reveal no preoperative periapical radioulucent but

(a)Preoperative radiography of mandibular left first molar tooth

(d) 1 year later, there are new periapical radioluces (as indicated by the arrows)

Q6:Why are the reported outcomes diverse?

Success rate of different studies

Case selection criteria

• The process of case selection involves the differentiation of potential candidates for treatment according to their prognosis; therefore, it is likely to determine the results of a clinical study .

In the majority of studies, cases were included without specific inclusion or exclusion criteria.

• Therefore, the reported outcomes may have been affected by inclusion of teeth with poor prognosis.


Case selection : inclusion of teeth with a compromised prognosis in the study sample.

If the sample of a clinical study includes many teeth with a compromised prognosis, the healing rate is

lower than if such teeth are not included.

Skoglund A and Persson G.1985


Multi-rooted teeth – individual roots vs. the whole tooth as the evaluated unit.

• The whole tooth was the evaluated as a unit in a clinical study (Friedman et al 1991), contributing one unit recorded as persistent disease.

• In contrast, if the roots were evaluated independently, the tooth would contribute two units: one healed and the other having persistent disease.

Tooth location and number of roots


Initial treatment or retreatment

Re-treatment 1 year

Root end filling 1 year Courtesy of Dr Steven Cohen, Toronto, Canada


Treatment providers

Providers of treatment in the different studies varied from oral and maxillofacial surgeons to endodontists, and from resident students to qualified specialists, with the reported outcomes varying accordingly.


Outcome of predominantly assessed by radiographs

limitations of radiographs:Radiographs are poorly standardized,

Subjected to changes in angulation and contrast. Different observers may not agree with what

they see on a radiograph, and the same observer may disagree with himself or herself if asked to reassess the same radiograph later.

Interpretation of radiographs is subject to bias.

These limitations of radiographs may undermine the reliability of the results.

• To minimize bias and inconsistency, assessment by blinded examiners who are calibrated for standardized interpretation is essential.

• This requirement has not been fulfilled in the majority of studies, and thus the reported outcomes are likely to reflect differences in radiographic interpretations.

Interpretation of radiographs


Follow-up period

• Healing after apical surgery is a dynamic process, requiring sufficient time for completion.

• There has been some debate about the appropriate follow-up period to demonstrate success. Some studies have reported significant lesion reduction within 1 year but have required as much as 3 years for full resolution.

• Kvist & Reit in a study reported 45 teeth that were healed at the 1-year follow-up, however recurrence of disease in four teeth (9%) at the 4-year follow-up.

Thus, short-term studies may not reflect the true, long-term outcome of apical surgery .

Because studies vary considerably in the extent of follow-up periods, their reported

outcomes are likely to reflect this variability


Extent of the follow-up period : outcome classification as ‘healing’ vs. ‘healed’.

-large excess of sealer -persistent apical periodontitis

root-end filling with MTA

3 months lesion is not reduced.

After 6 months 1 year and 8 months

The lesion is replaced with new bone; at the longer-term end-point. the outcome is assessed as ‘healed.’Ørstavik D, Pitt Ford TR, eds.

Essential Endodontology: Prevention and Treatment ofApical Periodontitis. Oxford: Blackwell Science, 1998.


Coronal restoration

The majority of studies do not provide detailed information about the restorative status of the treated teeth.

It is likely that in many studies the reported

outcomes are adversely influenced by inclusion of

teeth with defective or missing restorations.


Recall rate

• When subjects included in a study are not available for follow-up, their treatment outcome is unknown.

• The results may be considered invalid, unless the unavailable subjects are deceased or cannot be reached, suggesting that their absence is not related to the outcome.

• For this reason, a recall rate of at least 80% is required for a high level of evidence.

• The recall rates in the different studies vary from 18% to over 90%, while in many of them studies the recall rate is not even reported .

This may be one of the reasons for the inconsistent outcomes reported among all the studies.

For example, with a recall rate of 85%, Wang et al. report that 74% of the teeth have healed.According to their calculation, in the best-case scenario 80% of the teeth would be healed, while in the worst case scenario 57% would be healed.


The key to achieving a favorable outcome after endodontic treatment is related to controlling infection of the root canal system (i.e. eliminating infection, and preventing reinfection). Clinicians should be striving to achieve higher treatment outcomes by taking a biological approach to endodontic treatment and not simply concentrating on achieving a radiopaque line in root canal.

Conclusion

-Three main prognostic factors influence the outcome of root canal treatment and retreatment, the preoperative status of the periapical tissue, the quality of the root canal filling And the quality of the coronal restoration

Summary points

-Endodontically treated teeth should be reviewed to assess outcome- conventionally, this is done at least one year after the completion of endodontic treatment.

-The outcome of endodontic treatment may be deemed to be favorable, uncertain, or unfavourable, it is advisable to avoid using the terms “Success” and “Failure”.

-The probability of achieving a favorable outcome following endodontic treatment. i.e. the tooth is symptom- free and functional and the associated tissue appear clinically and radiographically healthy, can be over 95 percent.

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