Endodontic Medicaments Flashcards
What are the aims of endodontic treatment?
Remove all microorganisms from the root canal system
Remove all canal contents that may lead to growth of micro-organisms or the breakdown of toxic products and their release into periapical tissues
To prepare the canal for its disinfection and to develop a shape that permits a simple and effective root canal filling to be placed
To prevent micro-organisms from entering the tooth again and re-establishing infection in the root canal system as this causes apical periodontitis
Why are inter-appointment antibacterial dressings necessary?
Bystrom and sundqvist + Sjogren and Sundqvist observed that there were increased bacterial numbers in the empty canals between appointments.
Why are medicaments used?
Anti-bacterial action: Residual bacteria in the canals, tubules, fins, etc, contaminants between visits, periapical region contamination, periodontal tissues.
Reduce periapical inflammation
Prevent or reduce pain
Stimulate periapical repair
Prevent or inhibit inflammatory resorption
- Inactivating endotoxins and killing bacteria is why medicaments are so important for treatment during RCT *
What did microbiological analysis of teeth with failed endodontic treatment reveal?
ONE STUDY: 12% of microbes were present at the time of root filling only 33% of the cases healed.
88% no microbes were present and in these 80% healed.
The 47% difference was statistically significant
ANOTHER STUDY: All teeth were initially infected and 40% still had bacteria after instrumentation.
94% of the negative culture RCFs completely healed after 5 years and 68% of cases with positive culture RCF completely healed.
The 26% difference was statistically significant.
CONCLUSION: If there are organisms in the canals at time of treatment they will likely still be there after preparation and irrigation and so there is an emphasis on eliminating the bacteria from canals prior to placing the RCF.
Why should root canal treatment be done over several visits?
Canals need to be removed from canals prior to placing RCF.
This cannot be reliably achieved in one visit.
This demonstrates that it is not possible to remove all organisms from root canals without the support of inter-appointment anti-microbial dressings.
NOTE:
Some root canals heal after initial treatment with one visit
What has ledermix been shown to do to post-op pain?
Significantly less post-operative pain than the Ca(OH)2 group and the control group. (Ehrmann et al - IEJ 2003)
Why is bacteria removed from the canal?
Direct result of bacteria in the canal is inflammation. Removing them will reduce that. 2 type of inflammatory resorption internal and external.
Why is ledermix paste used?
Ledermix paste is an effective intracanal medicament for control of post-operative pain associated with acute apical periodontitis. (better than treatment with calcium hydroxide only and better than control group)
Reducing inflammation and killing bacteria with steroid + Antibiotic.
How long is ledermix paste used on the canal for?
3 to 4 months
Why are 2 or more visits used for treatment of teeth in need of RCT?
To increase the predictability of periapical healing by destroying more bacteria and by changing the environment within the canal and to reduce post-operative pain and external inflammatory root resorption.
Why should multiple visits still be used in cases of “elective endodontics” or pulpitis treatment?
Canals were found to be infected with bacteria in 29% of samples taken from root canal and pulp tissue.
Irreversible pulpitis often has primary acute apical periodontitis associated with it.
Why is there still pain following removal of pulp in a RCT?
Removing pulp implies severing the nerve fivers which will invoke periapical inflammation.
Neural response to removing the pulp is a derangement of the plexus of the nerves around the apical third of the root and axon sprouting/branching.
Inflammatory and neural changes continue for at least one year after RCT. (in cats)
This can explain the different sensation/discomfort reported by patients following endodontic treatment.
How can amount of nerve sprouting be reduced?
Corticosteroids can reduce the amount of nerve sprouting considerably but not totally.
How effective are corticosteroids for reducing pain?
C-Sts are even more effective than NSAIDs at reducing pain.
What is the purpose for using ledermix and calcium hydroxide?
Ledermix paste is a good agent to reduce inflammation while also having antibiotic properties.
Antibacterial action is mostly controlled by the calcium hydroxide.
Hard tissue repair is assisted heavily by calcium hydroxide.
How is odontopaste different to ledermix?
It is similar to ledermix but the antibiotic is clindamycin.
Also 1 - 2% Ca(OH)2
However, only one paper published about it. It is an alternative sometimes used when needed.
Can ledermix discolour teeth if used?
Only if not used correctly. It is an operator problem.
What are the components of ledermix paste?
Triamcinolone - 1% (corticosteroid)
Demeclocycline - 3% (antibiotic)
In a water soluble paste of:
Triethanolamine NF
Calcium chloride
Zinc oxide
Sodium sulphite
Polyethylene glycol
Distilled water
How does ledermix paste act on the rest of the tooth after application?
They diffuse through the dentinal tubules to the pulpal tissue and apical tissues
How is ledermix paste released?
Initially very rapidly and then slow and steady release.
Antibiotic diffuses slower than steroid due to binding with the calcium component of the hard tissue
How can medicaments diffuse through the tooth?
Normal diffusion within the canal/pulp.
Laterally through the dentinal tubules
Through the apex of the tooth.
What are the benefits of using ledermix paste?
Anti-inflammatory function to reduce and prevent pain and reduce nerve sprouting.
Anti bacterial action to reduce inflammation and start healing process
Inhibition of clastic cells reducing resorption of tooth and bone
Inhibition of PMN neutrophil collagenase reducing tissue destruction.
What preparations does calcium hydroxide come as?
Saline base (calasept plus, DT)
Methyl-cellulose base (Pulpdent paste)
Powder - to mix with various liquids
Impregnated on GP points (Roeko)
What jobs is calcium hydroxide used for?
Treating infected RCS and apical periodontitis is a use. Calcium hydroxide stimulates hard tissue repair.
5 - External apical inflammatory resorption.
6- lateral resorption. (Ledermix paste is used to treat external and lateral resorption initially. Then Calcium hydroxide is used to repair resorbed tissue.)
7- Apical inflammatory resorption.
8- internal inflammatory resorption that starts within the tooth. Treatment starts with the use of ledermix paste.
9 - accident known as a perforation into the canal calcium hydroxide is sometimes used depending on size of the perforation.
10 - Transverse root fracture or horizontal root fracture.
What is calcium hydroxide used for most often?
Most used because of antibacterial properties and hard tissue formation.
Only medicament that detoxifies bacterial LPS
Also dissolves necrotic tissue.
Has a high pH.
Calcium hydroxide should always be used as for control of infection.
What are the limitations to using calcium hydroxide?
Toxicity - initial and long-term
Increased replacement resorption
Increased ankylosis
May promote inflammatory resorption
What are the benefits of using a 50:50 mix of ledermix and calcium hydroxide?
Slower release of ledermix paste components and no change in activity of components meaning the dressing can last longer and maintain canal sterility for longer.
Increased anti-bacterial spectrum compared to using ledermix paste alone
Only a small reduction in pH levels reached in dentine
Lower tissue toxicity compared with calcium hydroxide
For how long should medicaments be used?
Absolute minimum time is 2 weeks since inflammation takes 10 - 14 days to resolve.
Most beneficial and maximum time for ledermix paste is 4 -> 6 weeks. For 50:50 solution that becomes 4 weeks to 3 months.
Maximum pH and stablity takes about 4 weeks for calcium hydroxide.
How are medicaments applied?
Spiral filler is the preferred and most effective/easiest method only if the canal has been enlarged.
If not apply with file
Injection is not advised and neither is paper point.
What are the risks of applying medicament via injection?
No control
Over-extension is likely via this method.
How is 50:50 mix of CS / Ab and Ca(OH)2 applied?
Saline-based Ca(OH)2: It is pre-mixed on a glass slab then applied witha file or spiral filler.
Methyl cellulose based Ca(OH)2: It is placed as CS/Ab in the canal first then the Ca/(OH)2 is applied with file or spiral filler
Ca(OH)2 powder: Pre-mixed on a glass slab then applied with file or spiral filler.
How is the first appointment arranged for RCT?
Consult: History, exam, radiographs, clinical tests. (Identify what is wrong and the cause)
Discussion, recommendations, management options
LA and rubber dam, remove all previous restorations, caries, and cracked portions of teeth. Assess feasibility of endodontics and a new restoration.
Access the pulp chamber check for pulpitis or infected canals. If pulpitis pulpectomy or pulpotomy. If infected canals remove debris or existing RCF.
Locate, negotiate and irrigate (EDTAC) all root canals.
Root canal medication - depends on diagnosis. Pulpitis = ledermix, infected canal = 50:50 mix ledermix + Ca(OH)2
Close the puip chamber - CW + Cavit
Interim restoration of tooth - usually GIC +/- band
Check and relieve tooth from all occlusal contacts
Post-operative instructions and discussion
How is the second appointment arranged for RCT?
Check the tooth and surrounding tissues
L.A. and rubber dam (Cuff technique usually)
Access cavity - through the interim restoration
Negotiate canals to estimate lengths
Establish working lengths with radiographs
Chemo-mechanically prepare the canals. (15% EDTAC + 1% NaOCl +15% EDTAC)
Medication - depends on the original diagnosis. Pulpitis = 50:50 mix ledermix + Ca(OH)2, infected canal Ca(OH)2 alone.
Close the cavity
How is the third appointment arranged for RCT?
LA not required. (Sensitivity should alert the operator to a problem that requires correction before RCF completed)
Rubber dam (cuff technique) and access cavity.
Irrigate (EDTAC) + use smaller file than master file.
Irrigate (EDTAC) + use smaller file than master file.
RCF - GP + AH 26
Close the canal cavity - CW, Cavit + IRM
Final Radiograph
Arrange the final restoration and review appointments
