Quartz 4

Root fillings - 2018_formatted_text

7 min read

The Rationale and Assessment of Root Canal Fillings123

“The outcome of endodontic treatment depends on how well the canals have been cleaned and disinfected …”

Pre-operative 2½ years later

The Two Core Aspects of Endodontics45

  • Treat the current / presenting problem
  • Prevent future infection

1. Treating the Current/Presenting Problem67

  • i.e. Pulpitis / infected canal + apical periodontitis

The process involves:

  • Diagnosis
  • Remove the cause (caries, cracks, restoration breakdown)
  • Remove pulp or infected debris
  • Clean and disinfect canal
  • Medicate
    • anti-inflammatory
    • anti-bacterial
  • Interim restoration

2. Preventing Future Infection89

  • i.e. Infected canal → apical periodontitis

This is achieved through:

  • Root canal filling
  • Coronal restoration
  • Oral hygiene, diet, etc

How do Root Canal Fillings (RCFs) Prevent Future Infection?10

  • Are they anti-bacterial?
    • Short term only - ?? Few days
  • Do they “seal” canals?
    • Doubtful
    • But much emphasis placed on this

The Role of the Canal Environment11

Conditions Favourable for Bacterial Colonisation of Root Canals12

  • Space
  • Co-colonising organisms
  • Low oxygen tension
  • Nutrients
    • Pulp tissue remnants
    • Necrotic debris
    • Saliva
    • Foods
    • Inflammatory exudate, etc

The main function of a RCF is to FILL the canal space and thus make it less favourable for bacterial colonisation to occur.

Louis Pasteur

“Don’t worry about the bacteria ….. …. it is the environment in which they live that is important”

Assessment of Root Canal Fillings (RCFs)1314

What makes a good RCF?

  • Clinically, we base our assessment on the radiographic appearance.

What do radiographs tell us about RCF’s?1516171819

  • Only how radiopaque the root filling material is and where it has been placed !!

1 yr later

  • ALSO: Radiographs do not indicate the degree of filling of the root canal SYSTEM

Lower 2nd Premolar (Dr Paul Fitz-Walter) Lower 1st Molar - Mesial root (J Endod 1986; 12: 354)

“Seal” vs. “Fill”: A Key Distinction20

SEAL-v-FILL
Block or preventObliterate the
entry into andcanal space
exit out of
the canal space

There is a DIFFERENCE !!

Aims of Root Canal Fillings21

APICAL “SEAL”CORONAL “SEAL”
Keep tissue fluids out of the canalKeep bacteria out of the canal
- Supply nutrients- Stop re-infection
Stop bacteria & / or endotoxins reaching the periapical regionKeep nutrients out of the canal
- Apical periodontitis- So bacteria can not survive
Need BOTH !!

Evaluating the “Seal”: Techniques and Materials22

  • How well do RCF’s seal canals?
    • Apically ?
    • Coronally ?
  • Is any technique better than others ?
  • Is any material better than others ?

Historical Background: The Focus on “Apical Seal”232425

One of the most commonly stated aims of endodontic treatment is to obtain an “apical seal”.

This is also described as:

  • A “three-dimensional root filling”
  • A “hermetic seal” (air -v- fluid?)

Commonly used clinical techniques for root canal fillings are largely based on early research work concerning “apical leakage”.

  • Mainly passive dye penetration studies
  • Some other techniques also used:
    • Electrochemical
    • Isotope penetration
    • Fluorometry
    • Spectrophotometry
    • Bacterial penetration

Critique of Early Leakage Studies2627

Apical Percolation and The “Washington Study”

The “Washington Study” attributed 60% of failures to apical “percolation” - BUT:

  • Apical percolation was not defined
  • Study was based on radiographic reviews
  • No evidence presented to support their claims about apical percolation
  • Apical percolation not actually tested
  • Study not controlled and not refereed

The Legacy of the “Washington Study”28

  • This study and other “leakage” studies formed the basis of many endodontic research projects for over 40 years.

  • Many refinements and recommendations for clinical techniques and materials were made as a result of these studies.

  • Most were either very poorly controlled experiments or had no controls at all

    • Typically “passive dye” studies

  • Time for penetration varies

    • e.g. 2 days, 3 days, 20 days, 30 days, 60 days, 90 days, etc.

Key Study: Ray & Trope - Int Endod J 1995293031

  • 1,010 teeth assessed radiographically for:
    • Outcome & standard of RCF’s and restorations
Findings (Ray & Trope - 1995)32

Percentage of cases with apical healing

RCF’s:Restorations:
GoodPoor
Good91.4 %44.1 %
Poor69.6 %18.1 %
Conclusion (Ray & Trope - 1995)33

“… The quality of the coronal restoration was more important than the quality of the RCF for apical periodontal healing …”

Example of coronal dye penetration

Revisiting the Purpose of RCFs34353637383940

So … if:

  • Apical dye penetration does not matter
  • Total filling of the canal is not essential
  • High technical standard is not essential

… why do we spend so much time and effort doing high quality RCF’s ??

Because … they:

  • Fill most of the space
  • Create an unfavourable environment for bacteria to survive in
  • Slow down the process of further infection and apical periodontitis
  • Give an indication of the overall technical standard of the endodontic treatment

The Realistic Role of RCFs in Preventing Future Infection414243

  • Root canal filling

  • Coronal restoration

  • Oral hygiene, diet, etc

  • BUT … Realistically …

    • RCF’s only slow down the onset of apical periodontitis

  • The “seal” of the coronal restoration is probably the most critical factor.

  • The RCF is not likely to have much effect on the outcome of the current treatment.

    • Only has a minor effect on how long the tooth may remain free of infection.

Criteria for When to Fill the Canal4445

The canal should be filled when all of the following have occurred:

  • Canal preparation and cleaning completed
  • There are no symptoms associated with the tooth
  • The canals can be dried
  • Mobility, percussion and palpation are normal
  • The draining sinus has healed - if present pre-op’ly
  • Swelling has resolved - if present pre-op’ly
  • Evidence of healing - if large lesion pre-op’ly

Footnotes

  1. Original PDF page 1: Root fillings - 2018, p.1 ↩

  2. Original PDF page 2: Root fillings - 2018, p.2 ↩

  3. Original PDF page 3: Root fillings - 2018, p.3 ↩

  4. Original PDF page 4: Root fillings - 2018, p.4 ↩

  5. Original PDF page 5: Root fillings - 2018, p.5 ↩

  6. Original PDF page 6: Root fillings - 2018, p.6 ↩

  7. Original PDF page 7: Root fillings - 2018, p.7 ↩

  8. Original PDF page 8: Root fillings - 2018, p.8 ↩

  9. Original PDF page 9: Root fillings - 2018, p.9 ↩

  10. Original PDF page 10: Root fillings - 2018, p.10 ↩

  11. Original PDF page 11: Root fillings - 2018, p.11 ↩

  12. Original PDF page 12: Root fillings - 2018, p.12 ↩

  13. Original PDF page 13: Root fillings - 2018, p.13 ↩

  14. Original PDF page 14: Root fillings - 2018, p.14 ↩

  15. Original PDF page 15: Root fillings - 2018, p.15 ↩

  16. Original PDF page 16: Root fillings - 2018, p.16 ↩

  17. Original PDF page 17: Root fillings - 2018, p.17 ↩

  18. Original PDF page 18: Root fillings - 2018, p.18 ↩

  19. Original PDF page 19: Root fillings - 2018, p.19 ↩

  20. Original PDF page 20: Root fillings - 2018, p.20 ↩

  21. Original PDF page 21: Root fillings - 2018, p.21 ↩

  22. Original PDF page 22: Root fillings - 2018, p.22 ↩

  23. Original PDF page 23: Root fillings - 2018, p.23 ↩

  24. Original PDF page 24: Root fillings - 2018, p.24 ↩

  25. Original PDF page 25: Root fillings - 2018, p.25 ↩

  26. Original PDF page 26: Root fillings - 2018, p.26 ↩

  27. Original PDF page 27: Root fillings - 2018, p.27 ↩

  28. Original PDF page 28: Root fillings - 2018, p.28 ↩

  29. Original PDF page 53: Root fillings - 2018, p.53 ↩

  30. Original PDF page 54: Root fillings - 2018, p.54 ↩

  31. Original PDF page 55: Root fillings - 2018, p.55 ↩

  32. Original PDF page 56: Root fillings - 2018, p.56 ↩

  33. Original PDF page 57: Root fillings - 2018, p.57 ↩

  34. Original PDF page 58: Root fillings - 2018, p.58 ↩

  35. Original PDF page 59: Root fillings - 2018, p.59 ↩

  36. Original PDF page 60: Root fillings - 2018, p.60 ↩

  37. Original PDF page 61: Root fillings - 2018, p.61 ↩

  38. Original PDF page 62: Root fillings - 2018, p.62 ↩

  39. Original PDF page 63: Root fillings - 2018, p.63 ↩

  40. Original PDF page 64: Root fillings - 2018, p.64 ↩

  41. Original PDF page 65: Root fillings - 2018, p.65 ↩

  42. Original PDF page 66: Root fillings - 2018, p.66 ↩

  43. Original PDF page 67: Root fillings - 2018, p.67 ↩

  44. Original PDF page 68: Root fillings - 2018, p.68 ↩

  45. Original PDF page 69: Root fillings - 2018, p.69 ↩

Graph View

Backlinks