Medication

Question 1

What are some advantages and disadvantages of single appointments (obturation without using medicaments?)

Answer 1

Advantage

• Decreased treatment time
• Better patient acceptance due to convenience
• Decreased cost (pt)
• Potentially increased profit (dentist)
• Immediate familarity with internal anatomy
• No risk of backterial leakage through temporary seal

Disadvantage:

• No easy access for post op flare up
• Clinician + patient fatigue
• No opportunity for intracanal disinfectant other than irrigant

Question 2

What are some advantages with using medicaments?

Answer 2

• No bacteria recoverable after one month
• Better removal of pulp tissue remnants
• Stimulation of hard tissue repair–>(stimulate hard tissue barrier in immature teeth with open apex to better facilitate obturation) (controversial)
• Reduced post op pain

Question 3

What factors should be considered when deciding whether to medicate?

Answer 3

• Time factor + patient ability to tolerate long procedures
• Haemorrhage control (if bleeding profusely should not continue to obturation)
• Management of post-op flare ups (more difficult after obturation, but takes 10 mins if medication in to flush out pus or inflammatory products)
• Case complexity
• Operator skill + experience

Question 4

How does biofilm grow? Why can antibiotics not remove root canal infection?

Answer 4

Adsorption of proteins to surface
Adhesion and cohesion of bacteria to each other and protein
Growth and metabolism of bacteria
As biofilm grows clumps get detached and travel to more distant sites
Properties:
Grow slowly, infection slow to produce overt symptoms
Antibiotics may relieve symptoms, but can not remove infection as can not access root canal space (same goes with host defence)
Therefore, once stop antibiotics can cause recurrent infection

Question 5

What are the ideal properties of medicaments?

Answer 5

Tissue effects:

• Antibacterial + Anti-inflammatory
• Pain reduction
• Non-irritant to periapical tissues
• Ability to stimulate hard tissue

Effectiveness

• Diffuse through dentine
• Quick acting + long lasting
• Effective in presence of pus + organic debris
• Water soluble

Operator + pt factors

• Non-staining
• Easy to use
• Inexpensive + long shelf life

Question 6

What medicaments should be used for:

• General endo cases
• Retereatment + dressing chagnes
• Trauma, luxation
• ROP

Answer 6

• Over 90% of cases use CaOH2
• Retreatment + dressing changes use chlorhex
• Trauma, luxation use odontopaste to treat resorption defects followed by CaOH2 to eliminate bacteria
• ROP (emergency with no time to remove entire pulpal structure) use leadermix or odontopaste to manage pain, followed by CaOH2 once preparation complete

Question 7

How should medicaments be delivered?

Answer 7

• Spiral fillers in slow speed with rubber point placed 4mm short of working length to avoid medicaments going beyond apex
• Hand files for teeth just accessed and canals very fine and unprepared or for canals with sharp curves→ reduced risk of fracturing rotary instruemnts
• Injection systems for wide open canal but be careful not to inject past apex

Question 8

What are the properties of CaOH and how does it worK? How long should it be left in the mouth?

Answer 8

• Aqueous or methylcellulose based
• Work via release of hydroxyl ions
• Produce highly alkaline environment that bacteria can not survive in
• Duration of dressing can vary from 1 week to several months (usually 1 week, but a fair amount is needed)

Properties:
-Bactericidal (pH 12.2)
Induces calcification by causing cell necrosis→ activates alkaline phosphatase→ calcific bridge formation)
-Promotes periapical healing (buffers acid prodcued in inflammatory fluids)
-Dissovles necrotic tissue
Inactivates endotoxin
pH decreases as get further out from main canal
-Effectiveness buffered/reduced by dentine + intracellular pH regulation (e.g. proton pump)

Question 9

What are the properties of chlorhexidine?

Answer 9

-Antimicrobial effects for 12 weeks
-Tends to be more effective antimicrobial than CaOH2 but no statistical significance
-Does not dissolve tissue
Less effective vs gram negative than gram positive bacteria
-Effectiveness reduced in presence of dentine powder and protein (like most other antimicrobial agents)
-Not in readily available formulation for endo

Question 10

What does odontopaste contain? Does it cause discoloration?

Answer 10

• Clindamycin hydrochloride 5% and triamcinolone acetonide 1% (can also get with pre-mixed 1-2% CaOH added)
• Does not cause discoloration