Week 3- Sealants, PRR & ART Flashcards
What are pits?
Small pinpoint depression located at junction or terminals of developmental grooves.
What are fissures?
Deep, very narrow channel, cleft, ditch or crevice formed at depth of developmental grooves during tooth development.
What depth of the fissure can be seen/accessed?
0.4mm
How do fissures form?
Calcification commences at the tips of the cusps and, as the cusps grow, they will fuse at the completion of the occlusal surface of the crown
What 5 types of fissures form when fusions are not complete?
V-type
U-type
I-type
IK-type
Inverted Y type
What is the issue with fissures?
- Provide ideal environment for caries
- Higher risk of undetected demineralisation
- Plaque retention
- Speed of penetration can be very fast with devastating results
What % of dental caries occur on occlusal surface?
80%
What are risk factors for pit and fissure caries?
Younger children
Permanent teeth
What are fissure sealants?
Introduction of a seal onto the occlusal, buccal and palatal pits and fissures of susceptible teeth creating a physical barrier to block biofilm nutrition and prevent acid-forming bacteria proliferation.
What is a useful tool to diagnose pit and fissure caries?
Bitewing radiographs
What is the benefit of fissure sealants?
- Important in preventing pit and fissure caries in high risk population
- Can arrest progression of early non-cavitated areas
What are the different sealant materials?
Resin based
GIC
What are the properties of resin based sealants?
- Durable
- Polymerization shrinkage = microleakage
- Stronger biofilm accumulation
What are the properties of GIC sealants?
- Chemical bond
- Fluoride release
- Occlusal forces – weaker
What are indications for fissure sealants?
- Presence of deep pits and fissures
- Suspected/initial occlusal caries in children and young adults
- Children susceptible to occlusal caries
- Children coming from non-fluoridated areas with increased caries experience
What are contraindications for fissure sealants?
- Shallow pits and fissures
- Well established carious lesions (cavitation)
- Teeth with proximal caries
- Partially erupted teeth (difficult for isolation)
What is the aim of fissure sealant materials?
Flow resin into depths of fissure
What are the steps of placing resin fissure sealant?
- Clean tooth with pumice/brush & water or minimal fissurotomy
- Rubber dam
- Etch and bond
- Apply sealant
- Check for overhangs and ditches
- Check occlusion
What is an alternative technique to clean the tooth prior to sealant placement?
Air abrasion
What are the steps of placing GIC fissure sealant?
- Clean tooth
- Condition with 10-20% polyacrylic acid for 10 secs
- Wash thoroughly with water and dry
- Isolate with cotton rolls
- Flow GIC in fissure (push in with lubricated gloved finger)
- Protect with Fuji coat or cocoa butter
Why may CR sealant fail?
- Partial lifting of sealant
- Resin has no antibacterial properties so caries can occur if seal is leaky
What are advantages of GIC sealants?
- Ion exchange adhesion
- True chemical adhesion
- Caries resistance from F release and presence of strontium
- F content can be recharged
- Micromechanical bond to enamel
Why should you place F varnish on GIC?
F is absorbed into filling and is recharged.
Are GIC or resin sealants lost more?
GIC
Are caries seen more with GIC or resin sealants?
Resin sealants
What is a PRR?
- Limited removal of carious tissue and restoration with composite resin or GIC.
- Fissure seal over the remaining sound, pits and fissures.
When doing PRR how much caries is removed?
Infected caries removed and affected left behind
What materials are used for PRR?
GIC, CR or both
Why should you seal GIC with resin coat?
Protects from water absorption while GIC matures
What is amorphous enamel and why is etching ineffective on this?
Mode adhesion with CR is through micromechanical retention. This is achieved by etching. Etching is effective if enamel rods are perpendicular to tooth structure. If rods are parallel, etching is ineffective. Amorphous enamel is outer structure of enamel where rods are parallel to eachother (not perpendicular). When you do fissurotomy, remove bacteria and amorphous enamel (to expose enamel to prismatic enamel). Then etching and bonding is effective.
What is required for caries to occur?
Strep mutans
What factors are part of risk assessment?
- Medical hx
- Social hx
- Dental hx
- OH + diet
- Lifestyle
What is ART?
Conservative method of managing carious lesions where traditional methods are not possible, viable or practical e.g. no rotary instruments, no electricity, non-compliant patient
What are the principles of ART?
Removal of dentine caries with hand instruments and restoration.
What are indications for ART?
General dentistry
Tx camps
School dental health program
Differently abled pts
Patients awaiting GA
Elderly-home bound
What is IRM?
Intermediate restorative material (ZOE). Has soothing effect on pulp.
What are contraindications for ART?
- Swelling
- Abscess or fistula
- Severe or prolonged toothache
- Cavity inaccessible
What are advantages of ART?
- Conservation of tooth structure
- Painless (no LA)
- Infection control simplified
- Cost effective
Why is GIC ideal for ART?
- Chemical bondage with tooth structure
- Non-irritant
- F releasing
What are advantages of silver fluoride (AgF)?
- Anti-microbial
- Promotes remineralization (Fl component)
- Inexpensive
- Non-invasive
- Can be administered by dental auxillaries (OHT)
How is AgF used?
- Tooth isolated
- Food debris removed but leave caries
- Apply AgF with microbrush to site for 1-3 minutes.
- Apply stannous fluoride to site (turns lesion black)
What is minimal intervention?
Maximum preservation of natural tooth structure to maintain strength and integrity.
What depth of dentine caries would be contraindicated for AgF?
Dentine caries need to be at least 1mm from pulp.
How can you differentiate between AgF and caries?
AgF makes tooth surface hard, caries are soft
What does it mean if AgF is lightening?
Caries are progressing
What is the highest risk fissure?
Bulbous widening + very short route to dentine
Can you do fissure sealant if dentine is involved?
No. If dentine is clearly involved (see in BW) go to a conservative PRR
What is the role of cavity conditioner?
Increases surface energy to improve wettability (does not etch)
