Fissure Sealants Flashcards
1
Q
Principle of fissure sealant
A
- material applied to pits and fissures on occlusal surfaces of molars and premolars
2
Q
Aim of fissure sealant
A
- plaque accumulation in difficult to clean areas
- destruction of enamel by plaque acids
- reduce occurrence of occlusal caries
3
Q
Fissure sealant is designed to be minimally invasive. Explain
A
- preventative treatment
- intended to reduce the risk of larger restorations needed later
4
Q
Flow of fissure sealants
A
- must fill pits and fissures - into narrow spaces
- penetration inversely related to viscosity
- control to spread and cover the whole required area
5
Q
Manipulation of fissure sealant
A
- does it need mixing?
- how easy is the mixing - 2 paste, 1 tube
- how easy is it to place - flow vs viscosity
- how is setting achieved - chemical or light activation
- setting reaction - WT, ST and exothermic shrinkage
6
Q
Durability of fissure sealant
A
- retention - prevention only happens when it’s there
- adhesion - need to be good to enamel, prevents marginal leakage which can cause caries
- wear needed to resist abrasion from opposing tooth, food, toothpaste
- maintain seal
7
Q
Protection provided by fissure sealant
A
- prevents leakage - initial seal from adhesion, long term may need reapplication
- fluoride release - no clear clinical evidence
8
Q
Types of fissure sealant
A
- cyanoacrylate cements
- polyurethane
- dimethacrylate resin-based
- glass ionomer cements
- resin modified GICs
9
Q
Explain cyanoacrylate cements
A
- like superglue
- unpredictable handling, hydrolysed over time
10
Q
Explain polyurethane
A
- like boat varnish
- doesn’t bond to tooth
11
Q
Explain dimethacrylate resin based
A
- similar to monomers in composite
- bis-GMA and diluent monomer
- UDMA based
- similar chemistry to composite filling materials
12
Q
Setting mechanisms of dimethacrylate resin based sealants
A
- chemically activated means short WT, long ST uncomfortable for young patients
- light activated has a long WT, short ST better for young patients
- UV-activated has low retention over 24 months
- for modern materials, no significant difference between chemical and light activated
13
Q
Effect of filler concentration for dimethacrylate resin based sealants
A
- filler conc related to viscosity
- filled products behave like flowable composites - increase in filler conc leads to increased viscosity - may affect penetration
- no filler leads to low wear resistance
- adding filler has no retentive advantage, water resistance no a sig problem if sealer is monitored in case re-app needed
14
Q
Explain acid etch before adding dimethacrylate resin based sealants
A
- 37% phosphoric acid
- solution (lower viscosity for flow) or a gel (higher viscosity for control)
- no clinical evidence that choice has an effect
- 10s-30s - depends on product
- enamel variability, moisture control, technique sensitivity
15
Q
Dentine bonding agents for fissure sealant
A
- primers - reduce moisture effect
- etch, dentine bonding agent/primer, sealant
- does add increased cost and complexity and no proven advantage in retention
