Tricalcium Silicate Cements as Dental Pulp Protection Materials Flashcards
Biodentine is composed of a powder and liquid; what are the powder constituents?
- Tricalcium silicate (main core material)
- Dicalcium silicate (2nd core material)
- Calcium carbonate and oxide (fillers)
- Iron oxide (shade)
- Zirconium dioxide (radiopacifier)
What are the liquid constituents of Biodentine?
- Hydrosoluble polymer - water reducing agent which has a surfactant effect
- Calcium chloride (accelerator)
What is the special feature of the hydrosoluble polymer?
It’s a superplasticising agent which reduces water content of the mixture while helping to retain it workability
What’s the setting reaction for Biodentine?
- Cement + water react = hydration reaction (hydraulic cements)
- Calcium silicates are partially dissolved in the liquid = hydrogel of hydrated silicate
- This precipitates on the remaining silicate particles’ surface and in the space between particles
- = decrease in material’s porosity + increase in compressive strength
- Material has hydrating tricalcium silicate cement grains surrounded by a matri of silicate hydrate, calcium hydroxide and calcium carbonate
- Calcium carbonate acts as an nucleating site on which calcium silicate hydrates - responsible for high calcium ion release
What are the physical properties of Biodentine?
- Similar compressive strength and hardness to dentine
- Similar flexural modulus as dentine
- High dimensional stability
- Low fluid uptake and sorption
- Doesn’t discolour
How does Biodentine appear on a radiograph?
- Similar radiopacity to dentine so more difficult to discern radiographically
What are the biological properties of Biodentine?
- Designed to be placed on both dentine and vital pulp tissue
Biodentine is “Bioactive”, what does this mean and what are the implications?
- Induces a biological response
- Induces pulpal cell proliferation and cytokine release
- Hard tissue formed with an interface synthesised with dentine via a dynamic mineral interaction zone similar to hydroxyapatite composition
- Plugs of material have been found in dentinal tubules
Biodentine is “Biocompatible”, what does this mean and what are the implications?
- Low risk of pulp or tissue reaction
- pH of 8.2 (slightly alkaline), promotes inflammatory cell recruitment
- Forms a good seal and has better microleakage resistance than RMGIC
- Excellent marginal adaption to cavity
- It can bond to affected dentine - if you treat with Sodium Hypochorite then you will have improved bond strength
What are the indications of Biodentine?
- Deep cavities - used as a dentine substitute
- Reversible pulpitis - use as a dressing and then smoothed down for subsequent restoration
- Trauma
- Pulpotomy in primary molars
- Perforation repair of the pulpal floor (going into the pulp)
Why would you use Biodetine rather than Calcium hydroxide?
- More effective for maintaining long-term pulp vitality after indirect and direct pulp-capping
- Higher success rate - less pulpal inflammatory response and more predictable hard dentine bridge formation than calcium hydroxide
Outline the clinical protocol for Biodentine
- Tooth isolation using rubber dam
- Prepare the cavity
- Clear margins
- Remove the infected dentine using a slow speed or excavator
- Mix the material - 6 drops of water and 30 sec mix
- Place in cavity
- Allow to set (12 mins)
- Leave as a dressing then smooth down for subsequent restoration
OR
Cover with resin composite or dental amalgam
- Follow up clinically and take radiograph
What shouldn’t you do if you’re placing Biodentine?
- Layer with GIC (reacts acid/base)
- Only use selective etch
- Use more than 2mm of resin composite to mask opacity
- Don’t desiccate as this will cause microleakage
