Clinical application of Pit and Fissure sealants

Question 1

Review the steps and procedures of Fissure Sealants

Answer 1

• Perform a bitewing radiograph to ensure no caries are evident
• Rubber Dam isolation and clamp
• Clean tooth with bristle brush
• Wash with water and dry
• Etch enamel with 37% orthophosphoric acid for 15 secs
• Wash with water for 15 secs to ensure complete remove of the phosphate salts which had dissolved from the tooth
• Dry with triplex
• Apply sealant with a thin brush/ ball applicator/ syringe and wait 5 seconds to allow it to flow into fissures. Bonding is not needed unless a flowable composite is used
• Apply sufficient material to cover all exposed pits and fissures
• Light cure for 20 seconds on each side of sealant surface
• A shiny, wet oxygen inhibition layer forms. Wipe it off with a cotton pellet because it has a nasty taste
* Do not overfill fissure systems as it will fracture easily

Question 2

Describe the bonding mechanism of fissure sealants

MENTION: Orthophosphoric acid

Answer 2

• For bonding, the enamel rods need to be etched
• This is achieved with 37% Orthophosphoric acid
• It is applied for 15-30 seconds
• An intermediate material/ bonding agent, low viscosity resin, are used. They are light cured
• The bonding agent is then able to chemically bond to the composite resin (IF RESIN IS NEEDED)
• The strength of the bonding agent with etched enamel is 25-30 MPs
* This is known as micromechanical bonding

Question 3

What are the properties of fissure sealants?

Answer 3

• Penetration coefficient: rate of flow of liquid into a capillary space
• Capillary action tends to draw sealant into orifice (openings) of pits and fissures
* Complete penetration of sealant is not necessary; so long as it occludes the neck region of a fissure, it does it’s job

Question 4

Discuss the indications for Pits and Fissure Sealants

Answer 4

• Consider age, oral hygiene, caries risk, diet, fluoride history, tooth type and tooth morphology
• Caries susceptible pits and fissures
* Ability to achieve moisture control

Question 5

Discuss the contra-indications for Pits and Fissure Sealants

Answer 5

• Evidence of caries: ICDAS 5
• Radiographic Code 4
* Unable to achieve rubber dam isolation

Question 6

What is the purpose of a pit and fissure sealant?

Answer 6

• They are lightly filled or unfilled resins
* Pit and fissure sealants serve as an effective preventative measure against the collection of bacteria and food bacteria which cannot be removed by a toothbrush in pits and fissures

Question 7

What is the different between a groove and a pit/fissure?

Answer 7

• Groove is a smooth depression on the occlusal surface of a tooth
• Pit/ fissure is an enamel fault which results from the noncoalescence (failure to meet) of enamel during tooth formation

Question 8

What are the materials used in fissure sealants?

Answer 8

• Low viscosity resins
• BIS-GMA (resin) dilutes with TEGDMA to reduce viscosity
• Colorant: titanium dioxide to make appearance slightly different from occlusal enamel
• Some inorganic filler particles are added for radiopacity, radiolucency and wear resistance
* For etching purposes, very little filler is used. (Too much filler = hard to penetrate)

Question 9

Describe ClinPro as a fissure sealant

Answer 9

• It is a fluoride releasing, pit and fissure sealant
• It starts off pink and changes to an opaque off-white when exposed to light
• Change of colour is not a cure indicator; it has to be cured with recommended time
• BIS-GMA/ TEGDMA resin composition
* Wipe off exhibition layer after curing

Question 10

Describe flowable composites as a fissure sealant

Answer 10

• Usually packed in syringes for direct application
• They have a higher inorganic filler content
* While this makes it more wear resistant, it also means the material cannot easily flow into etched enamel
* Thus, a bond is required before applying a flowable composite, as the flowable will adhere to the bond

Question 11

What is the difference between , unfilled/ lightly filled resin, flowable composites and composite resin?

Answer 11

Unfilled resin/ lightly filled resin:

• No filler/ little filler used
• Used mainly as a fissure sealant

Flowable composites:

• Has a higher filler content
• Requires a bonding agent

Composite resin

• Filled with many inorganic fillers
• Used on occlusal bearing surfaces
• Requires bonding surfaces