**Treatment Outcomes, Persistent Radiolucencies, Options for Management** **W/Prof. Paul V. Abbott AO** --- **Evaluation of Endodontic Treatment** **Winthrop Prof. Paul V. Abbott AO** *BDSc, MDS, FRACDS(Endo), FPFA, FADI, FICD, FACD, FIADT* Specialist Endodontist Winthrop Professor of Clinical Dentistry - The University of Western Australia --- **That root-filled tooth now has a periapical area .....** **What next ???** --- *2nd Year DMD - 2020* *Page 1* # **Treatment Outcomes, Persistent Radiolucencies, Options for Management** **W/Prof. Paul V. Abbott AO** *BDSc, MDS, FRACDS(Endo), FPFA, FADI, FICD, FACD, FIADT* Specialist Endodontist Winthrop Professor of Clinical Dentistry - The University of Western Australia --- ## **That root-filled tooth now has a periapical area ..... What next ???** > [!example] Case Example > ==When a root-filled tooth presents with a periapical radiolucency, a practitioner must diagnose the cause and determine the next steps. For example, a tooth with both periapical and lateral radiolucencies was successfully retreated. The healing of both areas suggested the cause was an infected root canal system, including an infected lateral canal, rather than a crack or perforation. This illustrates the core principle: successful outcomes are achieved by correctly diagnosing the problem (the cause), removing that cause (e.g., bacteria), and preventing reinfection.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 2 --- **That root-filled tooth now has a periapical area ..... What next ???** - **Why was there healing?** - **Diagnosis** - Provisional - Investigated - Confirmed - **Cause(s)** - Identified - Removed --- **Endodontic Treatment** - What is “success” ? - What is “failure” ? **OUTCOME of Treatment** --- 2nd Year DMD - 2020 Page 2 - **Why was there healing?** - **Diagnosis** - Provisional - Investigated - Confirmed - **Cause(s)** - Identified - Removed --- ## **Evaluation of Endodontic Treatment** - What is “success” ? - What is “failure” ? > [!info] > ==Evaluating the outcome of root canal treatment is crucial for both the patient and the practitioner. It helps determine if the treatment has worked and if the tooth remains stable over time. A root-filled tooth is still susceptible to long-term issues like restoration breakdown and bacterial reinfection, similar to a vital tooth.== **OUTCOME of Treatment** > [!abstract] Success vs. Outcome > ==The traditional terms **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 3 Flowchart showing Outcome of Endodontic Treatment with categories: Favourable, Uncertain (Need more time), Unfavourable, and Not known (Patient has not returned for review) ```mermaid flowchart TD A[100 Root Canal Treatment] A --> B[Favourable<br>35] A --> C[Uncertain<br>12] A --> D[Unfavourable<br>3] A --> E[Not known<br>50] B --> F[+45] C --> G[+10] D --> H[+2] F --> I[=70%] G --> J[=90%] E --> K[10 Favourable] E --> L[20 Uncertain] E --> M[10 Unfavourable] K & L & M --> N[=55% = 65%] ``` ```mermaid flowchart TD A[100 Root Canal Treatment] A --> B[Favourable<br>35] A --> C[Uncertain<br>12] A --> D[Unfavourable<br>3] A --> E[Not known<br>50] B --> F[+45] C --> G[+10] D --> H[+2] F --> I[=70%] G --> J[=90%] E --> K[10 Favourable] E --> L[20 Uncertain] E --> M[10 Unfavourable] K & L & M --> N[=55% = 65%] ``` **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 5 --- **Outcome of Endodontic Treatment** - What CRITERIA should be used to assess the outcome of endodontic treatment? - Histological - Clinical - Radiographic - Functional - Patient’s perceptions --- **Outcome of Endodontic Treatment** **Histological Criteria** - No inflammatory cells - No scar tissue - Hard tissue repair - Bone - Cementum - No resorption - Tooth - Bone > **The IDEAL results !!!** > **BUT ... We can NOT assess these criteria in the clinical situation with our patients !!!** --- ## **Outcome of Endodontic Treatment** ### **Criteria for Assessment** - What CRITERIA should be used to assess the outcome of endodontic treatment? - Histological - Clinical - Radiographic - Functional - Patient’s perceptions **Use a combination of these criteria** ### **Histological Criteria** - No inflammatory cells - No scar tissue - Hard tissue repair - Bone - Cementum - No resorption - Tooth - Bone > **The IDEAL results !!!** > **BUT ... We can NOT assess these criteria in the clinical situation with our patients !!!** **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 6 --- **Outcome of Endodontic Treatment** **Histological Criteria** - No inflammatory cells - No scar tissue - Hard tissue repair - Bone - Cementum - No resorption - Tooth - Bone **However .....** **These criteria MUST be used to evaluate endodontic treatment during RESEARCH** **Results of research can then be used clinically to provide more predictable treatment outcomes** --- **Outcome of Endodontic Treatment** **What CRITERIA should be used to assess the outcome of endodontic treatment?** - Histological - Clinical - Radiographic - Functional - Patient’s perceptions **Use a combination of these criteria** --- 11 12 **However .....** **These criteria MUST be used to evaluate endodontic treatment during RESEARCH** **Results of research can then be used clinically to provide more predictable treatment outcomes** # Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 7 ## Outcome of Endodontic Treatment ### CRITERIA for a Favourable Outcome: - Lack of symptoms > But a lack of symptoms does not imply the lack of disease #### The “Toronto study” - JoE 2003 - 95% of cases had no symptoms … but: - Only 85% had repair evident radiographically --- ## Outcome of Endodontic Treatment ### CRITERIA for a Favourable Outcome: - Lack of symptoms - Lack of evidence of ongoing pathosis - Radiographic signs of bone repair > Or no new radiolucency developing - No radiographic signs of resorption - Function maintained - Patient - comfortable tooth, no complaints ### **CRITERIA for a Favourable Outcome:** - Lack of symptoms > But a lack of symptoms does not imply the lack of disease - Lack of evidence of ongoing pathosis > [!info] > ==There is no swelling, draining sinus tract, or other soft tissue abnormalities.== - Radiographic signs of bone repair > Or no new radiolucency developing > [!info] > ==A pre-existing radiolucency has healed or is progressively getting smaller.== - No radiographic signs of resorption - Function maintained - Patient - comfortable tooth, no complaints #### **The “Toronto study” - JoE 2003** - 95% of cases had no symptoms … but: - Only 85% had repair evident radiographically > [!info] > ==This large study highlighted the discrepancy between symptoms and disease. This reinforces that many dental conditions, including chronic apical periodontitis, are asymptomatic.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 8 --- **Outcome of Endodontic Treatment** **WHEN should we assess the outcome?** - **6 months** - initial indication - **1 - 3 years** - more accurate assessment - **5 years** - generally considered the time required to *accurately* assess outcome of the endodontic treatment - **> 5 years** - now really assessing the *restoration* rather than the RCF --- *Byström et al Endod Dent Traumatol 1987; 3: 58-63* Graph showing healing over time with observation periods labeled 6 months to 10 years, and reference to Byström et al study. ### **WHEN should we assess the outcome?** > [!info] > ==There is no single ideal time interval for assessment, as healing rates vary significantly between patients. A Swedish study showed that large lesions could heal in 6 months, while smaller ones could take up to 5 years.== - **6 months** - initial indication - **1 - 3 years** - more accurate assessment - **5 years** - generally considered the time required to *accurately* assess outcome of the endodontic treatment - **> 5 years** - now really assessing the *restoration* rather than the RCF > [!info] > ==The root filling has done its job; the longevity of the tooth now depends on preventing reinfection.== *Byström et al* *Endod Dent Traumatol* *1987; 3: 58-63* **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 9 --- **Outcome of Endodontic Treatment** **CRITERIA for an *Unfavourable Outcome*:** → Anything that does not achieve the desired results for a favourable outcome - Usually because of either: → *Bacteria persisting in canals* → *New bacteria entering the canals* → *Ongoing periapical disease* → true cyst, extra-radicular infection, FBR --- **Outcome of Endodontic Treatment** **Unfavourable Outcomes** *Byström et al* *Endod Dent Traumatol* *1987; 3: 58-63* Bar chart showing "Size of the Lesion (mm)" vs. "Observation Period (Years)" with reference to Byström et al 1987. ### **CRITERIA for an *Unfavourable Outcome*:** → Anything that does not achieve the desired results for a favourable outcome - Usually because of either: → *Bacteria persisting in canals* → *New bacteria entering the canals* → *Ongoing periapical disease* → true cyst, extra-radicular infection, FBR > [!info] > ==Unfavourable outcomes are often evident earlier than favourable ones, as the radiolucency may fail to decrease in size or may even enlarge.== *Byström et al* *Endod Dent Traumatol* *1987; 3: 58-63* **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 10 --- **Outcome of Endodontic Treatment** **Criteria for Uncertain / Surviving cases** → When at least one of the criteria for a favourable outcome has not been achieved but the other criteria have been achieved - for example: → The pre-operative radiolucency has not healed completely or has not healed at all → The patient has no symptoms → There are no other clinical signs → The patient can function normally on the tooth → Typically noted at a review appointment --- **Outcome of Endodontic Treatment** **Uncertain / Surviving cases** *Byström et al* *Endod Dent Traumatol* *1987; 3: 58-63* Graph showing "SIZE OF THE LESION" vs "OBSERVATION PERIOD (YEARS)" with multiple declining curves labeled with years (e.g., 1, 2, 3, 4). A box notes "Byström et al Endod Dent Traumatol 1987; 3: 58-63". ### **Criteria for Uncertain / Surviving cases** → When at least one of the criteria for a favourable outcome has not been achieved but the other criteria have been achieved - for example: - The pre-operative radiolucency has not healed completely or has not healed at all - The patient has no symptoms - There are no other clinical signs - The patient can function normally on the tooth - Typically noted at a review appointment > [!info] > ==This may indicate the presence of **periapical scar tissue**. Such teeth have *Byström et al* *Endod Dent Traumatol* *1987; 3: 58-63* **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 11 **A new way to consider root-filled teeth with periapical radiolucencies:** - Based on **WHEN** the radiolucency occurs: **① Early** - occur soon after treatment → May be a true “failure” of the endodontic treatment - or the operator!!! → OR: may be due to a true cyst, an extra-radicular infection, a foreign body reaction or a periapical scar **② Late** - occur many years later → A “new disease” - rather than a “failure” of endodontic treatment Radiographic sequence showing Pre-op 1988, RCF 1988, 1 Yr Recall 1989, 5 Yrs Recall 1993, 8 Yrs Recall 1996, 16 Yrs Recall 2004 — labeled “Example: Uncertain / Surviving Case” with green and red arrows indicating radiolucency changes over time. ## **Considering Root-Filled Teeth with Periapical Radiolucencies** A new way to consider root-filled teeth with periapical radiolucencies is based on **WHEN** the radiolucency occurs: **① Early** - occur soon after treatment > [!note] > ==**(Persistent Radiolucency < 5 years post-treatment)**== → May be a true “failure” of the endodontic treatment - or the operator!!! → OR: may be due to a true cyst, an extra-radicular infection, a foreign body reaction or a periapical scar **② Late** - occur many years later > [!note] > ==**(New Radiolucency > 5 years post-treatment)**== → A “new disease” - rather than a “failure” of endodontic treatment **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 12 --- **Unfavourable Endodontic Outcomes** - **True “failures” of endodontic treatment** - Occur a short time after treatment - Due to bacteria being left behind at the time of the previous treatment - Up to 5 years after treatment - Probably due to: - Inadequate treatment techniques - Inadequate asepsis during treatment - Inadequate temporaries during treatment - Inadequate restoration after the RCF - Etc, etc --- **Time Since Previous Endodontic Treatment until Re-Treatment Required** *Allen et al – J Endod 1987* <table> <thead> <tr> <th>No. of Years</th> <th>% of cases</th> <th>Cum. %</th> </tr> </thead> <tbody> <tr> <td>&lt; 1</td> <td>21.9 %</td> <td>21.9 %</td> </tr> <tr> <td>1 - 2</td> <td>37.3</td> <td>59.2</td> </tr> <tr> <td>2 - 5</td> <td>13.7</td> <td>72.9</td> </tr> <tr> <td>&gt; 5</td> <td>27.1</td> <td>100.0</td> </tr> </tbody> </table> *No. of cases examined: 1300* ## **Unfavourable Endodontic Outcomes** ### **True “failures” of endodontic treatment** - Occur a short time after treatment - Due to bacteria being left behind at the time of the previous treatment - Up to 5 years after treatment - Probably due to: - Inadequate treatment techniques - Inadequate asepsis during treatment - Inadequate temporaries during treatment - Inadequate restoration after the RCF - ==The patient failing to have a permanent restoration placed== - Etc, etc ### **Time Since Previous Endodontic Treatment until Re-Treatment Required** *Allen et al – J Endod 1987* | No. of Years | % of cases | Cum. % | | :--- | :--- | :--- | | < 1 | 21.9 % | 21.9 % | | 1 - 2 | 37.3 | 59.2 | | 2 - 5 | 13.7 | 72.9 | | > 5 | 27.1 | 100.0 | *No. of cases examined: 1300* > [!info] > ==The study found that **73%** of cases required retreatment within 5 years of the original procedure. This data supports the concept that early radiolucencies are often linked to shortcomings in the initial treatment.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 13 --- ### Time Since Previous Endodontic Treatment until Re-Treatment Required **Abbott 1998** <table> <thead> <tr> <th>No. of Years</th> <th>% of cases</th> <th>Cum. %</th> </tr> </thead> <tbody> <tr> <td>&lt; 1</td> <td>21.2 %</td> <td>21.2 %</td> </tr> <tr> <td>1 - 2</td> <td>15.8</td> <td>37.0</td> </tr> <tr> <td>2 - 5</td> <td>24.0</td> <td>61.0</td> </tr> <tr> <td>&gt; 5</td> <td>39.0</td> <td>100.0</td> </tr> </tbody> </table> No. of cases examined: **575** --- ### “Infected Canal Disease Cycle” - Small number of bacteria in the canal **Left at time of treatment** - Gradual proliferation / increase in numbers **Chronic situation for some time** - Periapical response develops **No symptoms until response well established** - Gradual increase in periapical involvement **Acute phase when conditions suitable** - Many factors can affect the “balance” situation **e.g. Other illness, treatment, stress, tiredness, etc** - **This cycle can take ?? 3 mths - 5 yrs** ### **Time Since Previous Endodontic Treatment until Re-Treatment Required** **Abbott 1998** | No. of Years | % of cases | Cum. % | | :--- | :--- | :--- | | < 1 | 21.2 % | 21.2 % | | 1 - 2 | 15.8 | 37.0 | | 2 - 5 | 24.0 | 61.0 | | > 5 | 39.0 | 100.0 | No. of cases examined: **575** > [!info] > ==The speaker's own practice data showed a similar trend, with approximately **60%** of retreatments occurring within 5 years.== ### **“Infected Canal Disease Cycle”** > [!info] > ==When a small number of bacteria are left in the canal or enter during treatment, they typically cause asymptomatic chronic apical periodontitis. Over months or years, the bacteria multiply, and the periapical lesion grows. Symptoms (an acute exacerbation or - Small number of bacteria in the canal **Left at time of treatment** - Gradual proliferation / increase in numbers **Chronic situation for some time** - Periapical response develops **No symptoms until response well established** - Gradual increase in periapical involvement **Acute phase when conditions suitable** - Many factors can affect the “balance” situation **e.g. Other illness, treatment, stress, tiredness, etc** - **This cycle can take ?? 3 mths - 5 yrs** **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 14 --- **“Infected Canal Disease Cycle”** --- **A new way to consider root-filled teeth with periapical radiolucencies:** - Based on **WHEN** the radiolucency occurs: **① Early** - occur soon after treatment → May be a true “failure” of the endodontic treatment - or the operator!!! → OR: may be due to a true cyst, an extra-radicular infection, a foreign body reaction or a periapical scar **② Late** - occur many years later → A “new disease” - rather than a “failure” of endodontic treatment Pre-op 21 | 3 mths - RCF 21 | 9 mths - R/C 21 **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 15 --- **Root-Filled Teeth with Radiolucencies** × Radiolucency may occur many years after endodontic treatment **NOT a FAILURE of endodontics......** **...... But a NEW DISEASE** --- **Root-Filled Teeth with Radiolucencies** × Radiolucency may occur many years after endodontic treatment **NOT a FAILURE of endodontics......** **...... But a NEW DISEASE** **Bacteria re-enter the tooth** **Through:** • Broken down restorations • Caries • Cracks • Trauma - fractures • Etc, etc --- 29 30 ## **Late Occurrences: A > [!info] > ==When a radiolucency develops on a tooth more than 5 years after a root canal treatment that was previously deemed healed, it should be considered a **new disease process**, not a failure of the original endodontic therapy.== "New Disease"** - A radiolucency may occur many years after endodontic treatment. - **NOT a FAILURE of endodontics......** - **...... But a NEW DISEASE** - This occurs when **Bacteria re-enter the tooth** through: - Broken down restorations - Caries - Cracks - Trauma - fractures - Etc, etc # Treatment Outcomes, Persistent Radiolucencies, Options for Management **W/Prof. Paul V. Abbott AO** **2nd Year DMD - 2020** **Page 16** --- ## Restoration Breakdown - **All restorations have a finite life span** - **Bacterial penetration may be occurring for a long time before:** - **Symptoms** - **Clinical signs** - **Caries** - **Fracture** - **Dislodgment** - **etc, etc.....** --- ## Restoration Breakdown Figure illustrating dye penetration at crown/tooth interface and pulp chamber, referencing Pashley 1990 and Goldman et al 1992. ### **Restoration Breakdown** - **All restorations have a finite life span** > [!info] > ==Bacteria can penetrate through failing margins long before there are any clinical or symptomatic signs of failure.== - **Bacterial penetration may be occurring for a long time before:** - **Symptoms** - **Clinical signs** - **Caries** - **Fracture** - **Dislodgment** - **etc, etc.....** Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 17 Restoration Breakdown slide showing two images labeled "Labial view" and "Proximal view" with text "Example of coronal dye penetration" Restoration Breakdown slide showing two teeth with blue dye penetration, labeled "Coronal dye penetration" **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 18 --- ### **Bacterial Migration** - Many studies have demonstrated that various bacteria can migrate along the entire length of a root canal filling **Coronal → Apical** - Time for penetration varies e.g. 2 days, 3 days, 20 days, 30 days, 60 days, 90 days, etc. --- ### **Traditional Concept of Dentine** Diagram showing bacterial migration from coronal to apical through root canal filling (RCF) into broth, labeled with “Bacteria”, “RCF”, and “Broth” Cross-section diagram of tooth structure labeled: “Cementum”, “Dentine”, “Dentinal Tubule”, and “Pulp / Root Canal” ### **Bacterial Migration** > [!info] > ==Even under clinically and radiographically sound restorations, micro-gaps can allow fluid and bacteria to penetrate towards the pulp space. An experimental model demonstrated this process.== - Many studies have demonstrated that various bacteria can migrate along the entire length of a root canal filling. **Coronal → Apical** - Time for penetration varies - e.g. 2 days, 3 days, - 20 days, 30 days, - 60 days, 90 days, - etc. ### **Concepts of Dentine** - **1980's Concept of Dentine** - Cementum - Dentine - Dentinal Tubule - Pulp / Root Canal - **Now: The Dentine-Pulp Complex** - Cementum - Dentine - Dentinal Tubule - Pulp / Root Canal Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 19 **1980's Concept of Dentine** Cementum Dentine Dentinal Tubule Pulp / Root Canal **Now: The Dentine-Pulp Complex** Cementum Dentine Dentinal Tubule Pulp / Root Canal 37 38 **Treatment Outcomes, Persistent Radiolucencies, Options for Management** **W/Prof. Paul V. Abbott AO** --- **Dentine – Pulp complex** *Dr. Hien Ngo* 39 --- **The presence and distribution of bacteria in dentinal tubules of root-filled teeth** *Kwang S, Abbott PV.* *Int Endo J - 2014: 47, 600 - 610.* 40 --- **2nd Year DMD - 2020** **Page 20** #### **Dentine – Pulp complex** > [!info] > ==The dentine is not a solid barrier. It is a highly complex, porous structure. Scanning electron microscopy (SEM) reveals that dentinal tubules are not just simple parallel tubes but form an intricate, interconnected network.== *Dr. Hien Ngo* #### **The presence and distribution of bacteria in dentinal tubules of root-filled teeth** *Kwang S, Abbott PV.* *Int Endo J - 2014: 47, 600 - 610.* > [!info] > ==SEM studies on teeth from the bacterial leakage model showed that bacteria do not just stay in the main canal. They migrate extensively through the interconnected dentinal tubule network, eventually reaching the periapical tissues to cause a new lesion.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 21 **Experimental Model** Experimental model diagram showing a test tube with labeled layers: Bacteria (pink top layer), RCF (middle layer), Broth (orange bottom layer), with a red arrow indicating downward flow. Microscopic image (SEM) showing a surface with a circled area indicating a specific feature, labeled with imaging parameters: Acc.V 16.0 kV, Spot Magn 250x, Det SE, WD 11.4, scale bar 200 µm. ### **Experimental Model** Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 22 Microscopic images showing coronal entry points with annotations and scale bars. **Treatment Outcomes, Persistent Radiolucencies, Options for Management** **W/Prof. Paul V. Abbott AO** **45** **46** **2nd Year DMD - 2020** **Page 23** SEM micrograph showing surface texture with red arrow indicating feature, scale bar 20 µm SEM micrograph showing similar surface texture with red arrow indicating feature, scale bar 20 µm Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 24 Microscopic images labeled 6 and 7 showing surface structures with red annotations highlighting specific features. **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 25 Microscopic image labeled "Root canal wall" with red annotation and scale bar (20 µm). Composite microscopic image with numbered sections (4, 5, 6, 7, 8) and a red arrow indicating direction. **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 26 --- **Effect of Coronal Restorations** *Ray & Trope Int Endod J 1995* **Treatment Outcome - Favourable** <table> <thead> <tr> <th>RCF’s:</th> <th>Restorations: Good</th> <th>Restorations: Poor</th> </tr> </thead> <tbody> <tr> <td>Good</td> <td>91.4 %</td> <td>44.1 %</td> </tr> <tr> <td>Poor</td> <td>69.6 %</td> <td>18.1 %</td> </tr> </tbody> </table> --- **Effect of Coronal Restorations** *Ray & Trope Int Endod J 1995* **Concluded:** “… The quality of the coronal restoration was more important than the quality of the RCF for apical periodontal healing …” --- 51 52 ### **Effect of Coronal Restorations** *Ray & Trope Int Endod J 1995* **Treatment Outcome - Favourable** | RCF’s: | Restorations: Good | Restorations: Poor | | :--- | :--- | :--- | | Good | 91.4 % | 44.1 % | | Poor | 69.6 % | 18.1 % | **Concluded:** “… The quality of the coronal restoration was more important than the quality of the RCF for apical periodontal healing …” > [!success] > ==This underscores that the long-term longevity of a root-filled tooth is primarily dependent on the seal provided by the final restoration.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 27 --- **Outcome of Endodontic Treatment** - High quality endodontic treatment, based on sound biological principles, will improve the number of favourable outcomes - By removing intra-radicular bacteria - with accurate diagnosis, removal of the cause, aseptic techniques, mechanical cleaning, disinfection via irrigation and medication, interim and temporary restorations, good RCF’s, final restoration, etc - By reducing the extrusion of foreign bodies into the periapical tissues --- **Outcome of Endodontic Treatment** - **BUT**: there will be an *upper ceiling* to the number of favourable outcomes that can be achieved by conventional endodontic treatment - Due to the role played by true cysts and extra-radicular bacteria - The highest possible number of favourable outcomes will be limited by the incidence of these pathological entities --- 53 54 ## **Summary of Treatment Outcomes** - High quality endodontic treatment, based on sound biological principles, will improve the number of favourable outcomes. - By removing intra-radicular bacteria - with accurate diagnosis, removal of the cause, aseptic techniques, mechanical cleaning, disinfection via irrigation and medication, interim and temporary restorations, good RCF’s, final restoration, etc - By reducing the extrusion of foreign bodies into the periapical tissues - **BUT**: there will be an *upper ceiling* to the number of favourable outcomes that can be achieved by conventional endodontic treatment. - Due to the role played by true cysts and extra-radicular bacteria - The highest possible number of favourable outcomes will be limited by the incidence of these pathological entities. **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 28 --- **Persistent Radiolucencies** Due to: - **Intra-Radicular Infection** - **Extra-Radicular Infection** - **Foreign Body Reaction** - **Periapical True Cyst** - **Periapical Scar** --- **Guidelines for considering periapical radiolucencies associated with root-filled teeth** | Due to: | Initial Management | |--------------------------|----------------------------| | **Intra-Radicular Infection** | **Endodontic Re-treatment** | | **Extra-Radicular Infection** | **Periapical Surgery** | | **Foreign Body Reaction** | **Observe and Reassess** | | **Periapical True Cyst** | **Observe and Reassess** | | **Periapical Scar** | **Observe and Reassess** | 55 56 ## **Persistent Radiolucencies: Causes** Due to: - **Intra-Radicular Infection** - **Extra-Radicular Infection** - **Foreign Body Reaction** - **Periapical True Cyst** - **Periapical Scar** ### **Guidelines for considering periapical radiolucencies associated with root-filled teeth** | Due to: | Initial Management | | :--- | :--- | | **Intra-Radicular Infection** | **Endodontic Re-treatment** | | **Extra-Radicular Infection** | **Periapical Surgery** | | **Foreign Body Reaction** | **Observe and Reassess** | | **Periapical True Cyst** | **Observe and Reassess** | | **Periapical Scar** | **Observe and Reassess** | **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 29 --- **Guidelines for considering periapical radiolucencies associated with root-filled teeth** **Due to:** - **Intra-Radicular Infection** - **Extra-Radicular Infection** - **Foreign Body Reaction** - **Periapical True Cyst** - **Periapical Scar** **BUT the problem is that we can not clinically differentiate between all these conditions** --- **Spot the Difference!!** Four radiographic images labeled: Periapical True Cyst, Extra-Radicular Infection, Intra-Radicular Infection, Foreign Body Reaction, and Periapical Scar, with green arrows pointing to each. **BUT the problem is that we can not clinically differentiate between all these conditions** ### **Spot the Difference!!** > [!question] > ==An exercise with five different radiographs demonstrated that it is often impossible to differentiate between these five causes based on radiographic appearance alone. While some clues may exist (e.g., extruded material suggesting a foreign body reaction, or draining sinuses suggesting extra-radicular infection), the presentation is often ambiguous.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 30 **Guidelines for considering periapical radiolucencies associated with root-filled teeth** Due to: - **Intra-Radicular Infection** - **Extra-Radicular Infection** - **Foreign Body Reaction** - **Periapical True Cyst** - **Periapical Scar** **How common are each of these?** **Incidence of Radicular Cysts** *Nair et al - OS:OM:OP:OR:Endo 1996* <table> <thead> <tr> <th>Reference</th> <th>Cysts (%)</th> <th>Granuloma (%)</th> <th>Others (%)</th> <th>Total lesions (n)</th> </tr> </thead> <tbody> <tr><td>Sorenson<sup>28</sup></td><td>6</td><td>64</td><td>10</td><td>227</td></tr> <tr><td>Black et al.<sup>29</sup></td><td>8</td><td>94</td><td>—</td><td>220</td></tr> <tr><td>Sommer and Oh<sup>30</sup></td><td>7</td><td>93</td><td>—</td><td>227</td></tr> <tr><td>Lindberg et al.<sup>31</sup></td><td>9</td><td>80</td><td>11</td><td>110</td></tr> <tr><td>Wang<sup>32</sup></td><td>14</td><td>84</td><td>2</td><td>90</td></tr> <tr><td>Patterson et al.<sup>33</sup></td><td>14</td><td>84</td><td>2</td><td>90</td></tr> <tr><td>Stewart<sup>34</sup></td><td>17</td><td>54</td><td>23</td><td>100</td></tr> <tr><td>Stockdale & Chandler<sup>35</sup></td><td>17</td><td>77</td><td>6</td><td>1308</td></tr> <tr><td>Lin et al.<sup>36</sup></td><td>19</td><td>79</td><td>61</td><td>150</td></tr> <tr><td>Nicholson and Del Rio<sup>37</sup></td><td>22</td><td>79</td><td>19</td><td>150</td></tr> <tr><td>Rasmussen and Baxstrom<sup>38</sup></td><td>26</td><td>74</td><td>—</td><td>121</td></tr> <tr><td>Marksman et al.<sup>39</sup></td><td>41</td><td>48</td><td>11</td><td>796</td></tr> <tr><td>Bhaskar<sup>40</sup></td><td>42</td><td>52</td><td>6</td><td>1658</td></tr> <tr><td>Lehman and Loomis<sup>41</sup></td><td>44</td><td>45</td><td>11</td><td>800</td></tr> <tr><td>Schier et al.<sup>42</sup></td><td>51</td><td>43</td><td>6</td><td>87</td></tr> <tr><td>Prich et al.<sup>43</sup></td><td>61</td><td>46</td><td>—</td><td>101</td></tr> </tbody> </table> **Cysts: 6 - 55%** **Granuloma: 0 - 94%** **“Others”: 0 - 81%** ------------------------------- **Total: 18,026 lesions** ### **How common are each of these?** #### **Incidence of Radicular Cysts** *Nair et al - OS:OM:OP:OR:Endo 1996* <table> <thead> <tr> <th>Reference</th> <th>Cysts (%)</th> <th>Granuloma (%)</th> <th>Others (%)</th> <th>Total lesions (n)</th> </tr> </thead> <tbody> <tr><td>Sorenson<sup>28</sup></td><td>6</td><td>64</td><td>10</td><td>227</td></tr> <tr><td>Black et al.<sup>29</sup></td><td>8</td><td>94</td><td>—</td><td>220</td></tr> <tr><td>Sommer and Oh<sup>30</sup></td><td>7</td><td>93</td><td>—</td><td>227</td></tr> <tr><td>Lindberg et al.<sup>31</sup></td><td>9</td><td>80</td><td>11</td><td>110</td></tr> <tr><td>Wang<sup>32</sup></td><td>14</td><td>84</td><td>2</td><td>90</td></tr> <tr><td>Patterson et al.<sup>33</sup></td><td>14</td><td>84</td><td>2</td><td>90</td></tr> <tr><td>Stewart<sup>34</sup></td><td>17</td><td>54</td><td>23</td><td>100</td></tr> <tr><td>Stockdale & Chandler<sup>35</sup></td><td>17</td><td>77</td><td>6</td><td>1308</td></tr> <tr><td>Lin et al.<sup>36</sup></td><td>19</td><td>79</td><td>61</td><td>150</td></tr> <tr><td>Nicholson and Del Rio<sup>37</sup></td><td>22</td><td>79</td><td>19</td><td>150</td></tr> <tr><td>Rasmussen and Baxstrom<sup>38</sup></td><td>26</td><td>74</td><td>—</td><td>121</td></tr> <tr><td>Marksman et al.<sup>39</sup></td><td>41</td><td>48</td><td>11</td><td>796</td></tr> <tr><td>Bhaskar<sup>40</sup></td><td>42</td><td>52</td><td>6</td><td>1658</td></tr> <tr><td>Lehman and Loomis<sup>41</sup></td><td>44</td><td>45</td><td>11</td><td>800</td></tr> <tr><td>Schier et al.<sup>42</sup></td><td>51</td><td>43</td><td>6</td><td>87</td></tr> <tr><td>Prich et al.<sup>43</sup></td><td>61</td><td>46</td><td>—</td><td>101</td></tr> </tbody> </table> **Cysts: 6 - 55%** **Granuloma: 0 - 94%** **“Others”: 0 - 81%** ------------------------------- **Total: 18,026 lesions** > [!warning] Interpreting Historical Data > ==Older biopsy studies reported a wide and often high incidence of cysts (6-55%). However, these studies were flawed because they did not use complete serial sectioning. The landmark work by **Nair** used meticulous serial sectioning and found that in his specific sample of 256 lesions, only **9% were true cysts** and 6% were pocket cysts. 50% were abscesses and 35% were granulomas. It is crucial to note this is 9% of his specific sample, not 9% of all periapical lesions in the general population.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 31 --- ### **Biopsy Reports – Various Studies** <table> <thead> <tr> <th>Diagnosis</th> <th>Nair et al 1996</th> <th>Abbott 1999</th> </tr> </thead> <tbody> <tr> <td>Periapical Granuloma</td> <td>35%</td> <td>61%</td> </tr> <tr> <td>Periapical Abscess</td> <td>50%</td> <td>4%</td> </tr> <tr> <td>Periapical Cyst</td> <td>6% - Pocket<br>9% - True</td> <td>14%</td> </tr> <tr> <td>Periapical Scar</td> <td>N/R</td> <td>1%</td> </tr> <tr> <td>Foreign Body Reaction</td> <td>N/R</td> <td>20%</td> </tr> <tr> <td>Extra-Radicular Infection</td> <td>N/R</td> <td>2%</td> </tr> <tr> <td>Actinomycosis</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Keratocyst</td> <td>N/R</td> <td>N/R</td> </tr> </tbody> </table> **Notes:** - Few patients had pain - Not all teeth had RCF - Most had extensive caries or coronal breakdown - All teeth were extracted - Periapical soft tissue lesion had to be attached to tooth apex - “Represented an unknown fraction of all teeth extracted with periapical radiolucencies” - Complete serial sectioning - Light microscopy and TEM --- ### **Biopsy Reports – Various Studies** <table> <thead> <tr> <th>Diagnosis</th> <th>Nair et al 1996</th> <th>Abbott 1999</th> </tr> </thead> <tbody> <tr> <td>Periapical Granuloma</td> <td>35%</td> <td>61%</td> </tr> <tr> <td>Periapical Abscess</td> <td>50%</td> <td>4%</td> </tr> <tr> <td>Periapical Cyst</td> <td>6% - Pocket<br>9% - True</td> <td>14%</td> </tr> <tr> <td>Periapical Scar</td> <td>N/R</td> <td>1%</td> </tr> <tr> <td>Foreign Body Reaction</td> <td>N/R</td> <td>20%</td> </tr> <tr> <td>Extra-Radicular Infection</td> <td>N/R</td> <td>2%</td> </tr> <tr> <td>Actinomycosis</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Keratocyst</td> <td>N/R</td> <td>N/R</td> </tr> </tbody> </table> **Notes:** - Biopsies during surgery - Most teeth had Root Canal Re-treatment before surgery - Half had previous apical surgery – esp. with retrograde amalgam - Many had over-extended previous RCF - Some had continual pain or infection despite RC Re-tx - Light microscopy – only a few sections viewed --- **Page 61** **Page 62** ### **Biopsy Reports – Various Studies** **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 32 --- ### **Biopsy Reports – Various Studies** <table> <thead> <tr> <th>Diagnosis</th> <th>Nair et al 1996</th> <th>Abbott 1999</th> <th>Love & Firth 2009</th> <th>Schultz et al 2009</th> <th>Wang et al 2004</th> <th>Becconsall-Ryan et al 2010</th> </tr> </thead> <tbody> <tr> <td>Periapical Granuloma</td> <td>35%</td> <td>61%</td> <td>77%</td> <td>70%</td> <td>83%</td> <td>65%</td> </tr> <tr> <td>Periapical Abscess</td> <td>50%</td> <td>4%</td> <td>3%</td> <td>5%</td> <td>N/R</td> <td>3%</td> </tr> <tr> <td>Periapical Cyst</td> <td>6% - Pocket<br>9% - True</td> <td>14%</td> <td>18%</td> <td>23%</td> <td>14%</td> <td>32%</td> </tr> <tr> <td>Periapical Scar</td> <td>N/R</td> <td>1%</td> <td>3%</td> <td>1%</td> <td>3%</td> <td>1%</td> </tr> <tr> <td>Foreign Body Reaction</td> <td>N/R</td> <td>20%</td> <td>25% in a granuloma<br>2% in cysts<br>1% in scars</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Extra-Radicular Infection</td> <td>N/R</td> <td>2%</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Actinomycosis</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Keratocyst</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>1%</td> <td>N/R</td> <td>N/R</td> </tr> </tbody> </table> **Biopsies during surgery** **R’lucency persisting for >4 years or enlarging** **Some patients had pain** **RCT not possible - or already performed but no healing** **Light microscopy – up to four sections viewed** --- **63** **64** <table> <thead> <tr> <th>Diagnosis</th> <th>Nair et al 1996</th> <th>Abbott 1999</th> <th>Love & Firth 2009</th> <th>Schultz et al 2009</th> <th>Wang et al 2004</th> <th>Becconsall-Ryan et al 2010</th> </tr> </thead> <tbody> <tr> <td>Periapical Granuloma</td> <td>35%</td> <td>61%</td> <td>77%</td> <td>70%</td> <td>83%</td> <td>65%</td> </tr> <tr> <td>Periapical Abscess</td> <td>50%</td> <td>4%</td> <td>3%</td> <td>5%</td> <td>N/R</td> <td>3%</td> </tr> <tr> <td>Periapical Cyst</td> <td>6% - Pocket<br>9% - True</td> <td>14%</td> <td>18%</td> <td>23%</td> <td>14%</td> <td>32%</td> </tr> <tr> <td>Periapical Scar</td> <td>N/R</td> <td>1%</td> <td>3%</td> <td>1%</td> <td>3%</td> <td>1%</td> </tr> <tr> <td>Foreign Body Reaction</td> <td>N/R</td> <td>20%</td> <td>25% in a granuloma<br>2% in cysts<br>1% in scars</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Extra-Radicular Infection</td> <td>N/R</td> <td>2%</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Actinomycosis</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> </tr> <tr> <td>Keratocyst</td> <td>N/R</td> <td>N/R</td> <td>N/R</td> <td>1%</td> <td>N/R</td> <td>N/R</td> </tr> </tbody> </table> **Notes on Studies:** - **Nair et al 1996:** - Few patients had pain; most had extensive caries or coronal breakdown. - All teeth were extracted with the lesion attached. - Represented an "unknown fraction" of all extracted teeth with radiolucencies. - Utilized complete serial sectioning and microscopy (Light and TEM). - **Abbott 1999:** - Biopsies taken during surgery. - Most teeth had undergone Root Canal Re-treatment before surgery. - Half had previous apical surgery, especially with retrograde amalgam. - Many had over-extended previous RCFs or continual pain/infection despite re-treatment. - Utilized light microscopy on only a few sections. - **Love & Firth 2009, Schultz et al 2009, Wang et al 2004, Becconsall-Ryan et al 2010:** - Biopsies taken during surgery for radiolucencies persisting >4 years or enlarging. - Some patients had pain. - RCT was not possible or had already been performed with no healing. - Utilized light microscopy on up to four sections. > [!abstract] Summary > ==The key takeaway from comparing various clinical biopsy studies is that the reported incidence of cysts and other conditions varies widely depending on the sample population and diagnostic criteria.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** **W/Prof. Paul V. Abbott AO** **2nd Year DMD - 2020** **Page 33** --- ### **Outcome of Endodontic Treatment** - **BUT**: even with high quality “intracanal treatment”, there will still be an **upper limit** to the number of favourable outcomes that can be achieved by conventional endodontic treatment. Largely determined by the incidence of: - **Residual intracanal bacteria** → ?? 35 - 83 % - **Extra-radicular infection** → ?? 2 % - **Peri-radicular true cysts** → ?? 9 % - **Foreign body reactions** → ?? 20 - 25 % - **Periapical scars** → ?? 1 - 3 % > **Biopsy studies - limited value - only the % of the biopsies examined, not the % in all patients** --- ### **Specialist Endodontic Practice Service Mix - Surgical Cases** - **1986 - 1990** - **10.6% of all cases treated** > Abbott - J Endod 1994; 20: 253-7 - **1995 - 1999** - **1% of cases** - **2005 - 2010** - **0.1% of cases** --- **65** **66** ### **Implications for Treatment Outcome** - **BUT**: even with high quality “intracanal treatment”, there will still be an **upper limit** to the number of favourable outcomes that can be achieved by conventional endodontic treatment. Largely determined by the incidence of: - **Residual intracanal bacteria** → ?? 35 - 83 % - **Extra-radicular infection** → ?? 2 % - **Peri-radicular true cysts** → ?? 9 % - **Foreign body reactions** → ?? 20 - 25 % - **Periapical scars** → ?? 1 - 3 % > [!success] Clinical Takeaway > ==The relatively low incidence of true cysts and extra-radicular infections means that the vast majority of periapical radiolucencies are caused by **intra-radicular infections** (granulomas or abscesses) and are therefore treatable with non-surgical root canal retreatment.== > **Biopsy studies - limited value - only the % of the biopsies examined, not the % in all patients** ### **Specialist Endodontic Practice Service Mix - Surgical Cases** - **1986 - 1990** - **10.6% of all cases treated** > Abbott - J Endod 1994; 20: 253-7 - **1995 - 1999** - **1% of cases** - **2005 - 2010** - **0.1% of cases** > [!info] > ==This reflects a better understanding in the profession that most cases can and should be managed non-surgically first.== **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 34 --- **Guidelines for considering periapical radiolucencies associated with root-filled teeth** **Due to:** - **Intra-Radicular Infection** - **Extra-Radicular Infection** - **Foreign Body Reaction** - **Periapical True Cyst** - **Periapical Scar** > *Usually also have an infected root canal system — often the first problem* --- **Guidelines for considering periapical radiolucencies associated with root-filled teeth** - **Ideally: do endodontic re-treatment first** since most periapical radiolucencies are caused by, or are associated with, intra-radicular bacteria - Then the treatment will be more predictable and the rate of favourable outcomes will be higher → *Since the cause of the radiolucency is addressed* - **If still no healing, consider periapical surgery** - If re-treatment before surgery: 24% higher rate of healing than when surgery done alone (Grung et al - 1990) --- 67 68 ## **Management Guidelines for Persistent Radiolucencies** - The causes of persistent radiolucencies often include an infected root canal system, which is frequently the primary problem. - **Intra-Radicular Infection** - **Extra-Radicular Infection** - **Foreign Body Reaction** - **Periapical True Cyst** - **Periapical Scar** > [!info] > ==**Intra-radicular Infection** (bacteria inside the canal system) is the *most common cause*. The management depends entirely on the diagnosis, but all five conditions can appear as a radiolucency on an x-ray.== - **Ideally: do endodontic re-treatment first** since most periapical radiolucencies are caused by, or are associated with, intra-radicular bacteria. - Then the treatment will be more predictable and the rate of favourable outcomes will be higher. → *Since the cause of the radiolucency is addressed* - **If still no healing, consider periapical surgery. > [!tip] Fundamental Principle > ==The fundamental principle is to **retreat the root canal system first**. Surgery is only considered if non-surgical retreatment fails to lead to healing.== ** - If re-treatment before surgery: 24% higher rate of healing than when surgery done alone (Grung et al - 1990) **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 35 --- **Root-filled Tooth with a Periapical Radiolucency** - Non-Endodontic Origin - Persistent Periapical Radiolucency - New Periapical Radiolucency **Abbott - Endodontic Topics 2011** **Differential diagnoses for periapical radiolucencies associated with root-filled teeth** 1. A lesion that mimics a periapical radiolucency but is not endodontic in origin 2. A persistent radiolucency on a recently root-filled tooth (< 5 years ago) due to one of the following: - An intra-radicular infection - An extra-radicular infection - A foreign body reaction - A periapical true cyst, or - A periapical scar 3. A new radiolucency due to: - Any of the above presenting as a new lesion on a tooth that had the RCF done > 5 years ago --- Flowchart: Root-filled Tooth with a Periapical Radiolucency branching into Non-Endodontic Origin, Persistent Periapical Radiolucency, and New Periapical Radiolucency. Labelled "Abbott - Endodontic Topics 2011". ## **Differential Diagnoses for Periapical Radiolucencies on Root-Filled Teeth** *Abbott - Endodontic Topics 2011* 1. A lesion that mimics a periapical radiolucency but is not endodontic in origin. 2. A persistent radiolucency on a recently root-filled tooth (< 5 years ago) due to one of the following: - An intra-radicular infection - An extra-radicular infection - A foreign body reaction - A periapical true cyst, or - A periapical scar 3. A new radiolucency due to: - Any of the above presenting as a new lesion on a tooth that had the RCF done > 5 years ago. **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 36 --- **Differential diagnoses for periapical radiolucencies associated with root-filled teeth** 1. A lesion that mimics a periapical radiolucency but is not endodontic in origin --- **Root-filled Tooth with a Periapical Radiolucency** ```mermaid flowchart TD A[Root-filled Tooth with a Periapical Radiolucency] --> B[Non-Endodontic Origin] B --> C[See Table] C --> D[Refer patient to appropriate dental and/or medical specialist] D --> E[Review to confirm diagnosis and to ensure healing with no dental problems] ``` --- 71 72 ### **1. Non-Endodontic Origin** A lesion that mimics a periapical radiolucency but is not endodontic in origin. > [!info] > ==Examples include a lateral periodontal cyst, benign or malignant tumor, or an anatomical variation. If the tooth tests vital and there is no other evidence of an endodontic problem, the patient should be referred to the appropriate specialist (e.g., oral surgeon) for diagnosis and management.== ```mermaid flowchart TD A[Root-filled Tooth with a Periapical Radiolucency] --> B[Non-Endodontic Origin] B --> C[See Table] C --> D[Refer patient to appropriate dental and/or medical specialist] D --> E[Review to confirm diagnosis and to ensure healing with no dental problems] ``` **Treatment Outcomes, Persistent Radiolucencies, Options for Management** **W/Prof. Paul V. Abbott AO** **2nd Year DMD - 2020** **Page 37** --- **Differential diagnoses for periapical radiolucencies associated with root-filled teeth** 2. A persistent radiolucency on a recently root-filled tooth (< 5 years ago) due to one of the following: **A. An intra-radicular infection** **B. An extra-radicular infection** **C. A foreign body reaction** **D. A periapical true cyst, or** **E. A periapical scar** --- ```mermaid graph TD A[Root-filled Tooth with a Periapical Radiolucency] --> B[Persistent Periapical Radiolucency] B --> C[Endodontic Re-treatment] C --> D[Reassess & Review Healing] D --> E[Healed (Periapically Normal)] D --> F[No Change in Size of Radiolucency] D --> G[Healing (Radiolucency smaller)] F --> H[Assume Periapical Scar – but to reassess] H --> I[Review again] I --> J[No Further Change in Size of Radiolucency] J --> K[Assume Periapical Scar - Continue to Reassess & Review] K --> L[Review Every 3-5 yrs] G --> M[Continue to Review] M --> N[Review again] N --> O[No Further Change in Size of Radiolucency] O --> P[Assume Periapical Scar - Continue to Reassess & Review] P --> Q[Review Every 3-5 yrs] F --> R[Radiolucency Increased in Size] R --> S[Assume a Periapical Condition] S --> T[Periapical Surgery] S --> U[Extraction ± Prosthesis] C --> V[Treatment details known + RCF is Rad’ly Satisfactory] V --> W[Review again] W --> X[Review again] ``` ### **2. Persistent Radiolucency (< 5 years post-RCF)** A persistent radiolucency on a recently root-filled tooth (< 5 years ago) due to: **A. An intra-radicular infection** **B. An extra-radicular infection** **C. A foreign body reaction** **D. A periapical true cyst, or** **E. A periapical scar** > [!info] > ==Since the most likely cause is an **intra-radicular infection**, the primary management is **non-surgical retreatment**.== ```mermaid graph TD A[Root-filled Tooth with a Periapical Radiolucency] --> B[Persistent Periapical Radiolucency] B --> C[Endodontic Re-treatment] C --> D[Reassess & Review Healing] D --> E[Healed (Periapically Normal)] D --> F[No Change in Size of Radiolucency] D --> G[Healing (Radiolucency smaller)] F --> H[Assume Periapical Scar – but to reassess] H --> I[Review again] I --> J[No Further Change in Size of Radiolucency] J --> K[Assume Periapical Scar - Continue to Reassess & Review] K --> L[Review Every 3-5 yrs] G --> M[Continue to Review] M --> N[Review again] N --> O[No Further Change in Size of Radiolucency] O --> P[Assume Periapical Scar - Continue to Reassess & Review] P --> Q[Review Every 3-5 yrs] F --> R[Radiolucency Increased in Size] R --> S[Assume a Periapical Condition] S --> T[Periapical Surgery] S --> U[Extraction ± Prosthesis] C --> V[Treatment details known + RCF is Rad’ly Satisfactory] V --> W[Review again] W --> X[Review again] ``` **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 38 --- **Differential diagnoses for periapical radiolucencies associated with root-filled teeth** **3. A new radiolucency due to:** Any of the following presenting as a new lesion on a tooth that had the RCF done > 5 years ago **A. Apical Periodontitis** → 2º Acute Apical Periodontitis → Chronic Apical Periodontitis → Foreign Body reaction **B. Infection** → 2º Acute Apical Abscess → Chronic Apical Abscess → Extra-Radicular Infection **C. Periapical Cyst** → Pocket Cyst → True Cyst **D. Periapical Scar** *Most common + due to an infected root canal system* --- ```mermaid graph TD A[Root-filled Tooth with a Periapical Radiolucency] --> B[Healed Periapically Normal] A --> C[No Change in Size of Radiolucency] A --> D[Radiolucency Increased in Size] B --> E[Review Every 3-5 yrs] C --> F[Assume Periapical Scar - Continue to Reassess & Review] D --> G[Further Increase in Radiolucency Size - Assume a Periapical Condition] G --> H[Continue to Review] D --> I[Endodontic Re-treatment] D --> J[Periapical Surgery] D --> K[Extraction ± Prosthesis] I --> L[No Further Change in Size of Radiolucency] L --> M[Continue to Review] I --> N[Healing Radiolucency smaller] N --> O[Reassess & Review Healing] I --> P[Healed Periapically Normal] P --> Q[Review Every 3-5 yrs] ``` ### **3. New Radiolucency (> 5 years post-RCF)** A new radiolucency on a tooth that had the RCF done > 5 years ago, due to: - **A. Apical Periodontitis** → 2º Acute Apical Periodontitis → Chronic Apical Periodontitis → Foreign Body reaction - **B. Infection** → 2º Acute Apical Abscess → Chronic Apical Abscess → Extra-Radicular Infection - **C. Periapical Cyst** → Pocket Cyst → True Cyst - **D. Periapical Scar** *Most common + due to an infected root canal system* > [!info] > ==This represents a **new disease** due to reinfection, almost always from a failing coronal restoration. The management is the same as for a primary infection: **non-surgical retreatment**.== ```mermaid graph TD A[Root-filled Tooth with a Periapical Radiolucency] --> B[Healed Periapically Normal] A --> C[No Change in Size of Radiolucency] A --> D[Radiolucency Increased in Size] B --> E[Review Every 3-5 yrs] C --> F[Assume Periapical Scar - Continue to Reassess & Review] D --> G[Further Increase in Radiolucency Size - Assume a Periapical Condition] G --> H[Continue to Review] D --> I[Endodontic Re-treatment] D --> J[Periapical Surgery] D --> K[Extraction ± Prosthesis] I --> L[No Further Change in Size of Radiolucency] L --> M[Continue to Review] I --> N[Healing Radiolucency smaller] N --> O[Reassess & Review Healing] I --> P[Healed Periapically Normal] P --> Q[Review Every 3-5 yrs] ``` **Treatment Outcomes, Persistent Radiolucencies, Options for Management** W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 39 --- **SUMMARY** - **Do endodontic re-treatment first !!!** --- **Managing Persistent Radiolucencies** - Ideally: do endodontic re-treatment first since most periapical radiolucencies are caused by, or are associated with, intra-radicular bacteria - Therefore the rate of favourable outcomes will be higher - As shown by Grung et al (1990): → If re-treatment before surgery - 24% higher rate of healing than when surgery was done alone ## **SUMMARY** - **Do endodontic re-treatment first !!!** ### **Managing Persistent Radiolucencies** > [!abstract] A systematic, review-based approach should be followed: > 1. ==**Perform non-surgical retreatment.**== > 2. ==**Review at 6 months.**== > 3. ==**Assess the outcome:**== - ==**Healed:** Place the patient on a long-term (3-5 year) recall schedule.== - ==**Smaller / Unchanged:** Continue to review annually. If the lesion stabilizes but does not fully resolve, it may be a periapical scar, which only requires monitoring.== - ==**Larger:** If the lesion has increased in size, review again in 6 months. If it continues to enlarge, this suggests a true cyst, extra-radicular infection, or foreign body reaction. At this point, **periapical surgery** or **extraction** should be considered.== - Ideally: do endodontic re-treatment first since most periapical radiolucencies are caused by, or are associated with, intra-radicular bacteria. - Therefore the rate of favourable outcomes will be higher. - As shown by Grung et al (1990): → If re-treatment before surgery - 24% higher rate of healing than when surgery was done alone Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 40 **Conservative Treatment of a Large P-ap Lesion** GP + AH26 Pre-op 1 Yr later 1 Yr RC **Conservative Treatment of a Large P-ap Lesion** GP + AH26 Pre-op 1 Yr later *Courtesy Dr Geoff Heithersay – Adelaide* 79 80 # **Conservative Treatment of a Large Periapical Lesion** ## **Case 1: GP + AH26** - Pre-op - 1 Yr later - 1 Yr RC ## **Case 2: GP + AH26** - Pre-op - 1 Yr later - *Courtesy Dr Geoff Heithersay – Adelaide* Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO 2nd Year DMD - 2020 Page 41 **Conservative Treatment of a Large P-ap Lesion** *GP + AH26* Pre-op Ca(OH)₂ – 3 mths Ca(OH)₂ – 13 mths RF 13 mths *Courtesy Dr Geoff Heithersay – Adelaide* **Conservative Treatment of a Large P-ap Lesion** *MTA in the apical half / GP + sealer in coronal half* Pre-op 6 mths Post-op 2 yrs Post-op *Courtesy Dr George Bogen – Calif, USA* ## **Case 3: GP + AH26 with Calcium Hydroxide** *GP + AH26* - Pre-op - Ca(OH)₂ – 3 mths - Ca(OH)₂ – 13 mths - RF 13 mths - *Courtesy Dr Geoff Heithersay – Adelaide* ## **Case 4: MTA and GP** *MTA in the apical half / GP + sealer in coronal half* - Pre-op - 6 mths Post-op - 2 yrs Post-op - *Courtesy Dr George Bogen – Calif, USA* Treatment Outcomes, Persistent Radiolucencies, Options for Management W/Prof. Paul V. Abbott AO **Management Options** - **What are the options?** - No treatment - Extraction - Surgery - Re-treatment > **It depends on the DIAGNOSIS !!!** 83 2nd Year DMD - 2020 Page 42 # **Management Options** ## **What are the options?** - No treatment - Extraction - Surgery - Re-treatment > **It depends on the DIAGNOSIS !!!** - ==**No Treatment / Monitor:** Appropriate for a suspected periapical scar in an asymptomatic, functional tooth.== - ==**Extraction:** If the tooth is non-restorable or the patient declines other options.== - ==**Periapical Surgery:** Reserved for cases that do not heal after adequate non-surgical retreatment or where retreatment is not feasible.== - ==**Non-Surgical Retreatment:** The primary and initial treatment of choice for the vast majority of cases, as they are caused by intra-radicular infection.== [[O3 Treatment Outcomes, Persistent Radiolucencies, Options for Management.pdf#page=1|O3 Treatment Outcomes, Persistent Radiolucencies, Options for Management, 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