LESIONS IN THE PITS & FISSURES

what areas of the teeth are plaque stagnation areas

• occlusal

• buccal

• cingulum pits

• fissures

why are pits and fissures areas of plaque stagnation

• pits and fissures are often complex and inaccessible to oral hygiene measures - most common site to develop carious lesions

history of fissure sealants

in what two situations are fissure sealants used

1. a non-cavitated carious lesion

2. to protect sound pits and fissures in patients of high caries risk

how does fissure sealant protect against plaque development

FS provides a smoother, easier to clean surface compared to the anatomy of regular pits and fissures

what things should be considered in a caries risk assessment

what are indications for fissure sealant

• early pit and fissure carious lesions found during assessment

• prevention of caries in high-risk caries groups

• prevention of caries in a particularly complex fissure pattern that is proving difficult to clean

• DBOH recommends the sealing of all permanent molars in children and young adults of high caries risk

what are contraindications of fissure sealant

• cavitated carious lesions

• inadequates moisture control

  • FS are (mostly) resin-based and therefore hydrophobic

• no caries experience/ low caries risk

what are benefits of fissure sealants

• can be used to treat early carious lesions/ prevent caries in high-risk groups

• can suppress bacteria remaining in the fissure pattern by blocking their nutrient supply

• makes complex fissure patterns more cleansable

• proven to reduce caries incidence in high-risk groups

outline fissure sealant materials

there are two principal groups of materials:

• resin-based fissure sealants - most used

• glass-ionomer fissure sealants - more common in paediatric clinics

give an example of a situation where a glass-ionomer fissure sealant would be opted for

where moisture is more likely to be present e.g. fissure sealing a partially erupted tooth

instruments and materials needed to place a fissure sealant

• routine examination kit: mirror, probe, tweezers

• high-speed handpiece: adjusting and finishing the sealant

• slow-speed handpiece: used with bristle brush and pumice

• isolation kit

• etchant and microbrush

• resin-based sealant, composite gun and light-cure unit

• articulating paper and finishing burs

what is the most common cause of FS failure

saliva contamination

how many teeth should be isolated during FS

• single tooth isolation is sufficient for placing a FS

• often also need LA due to clamp pressure

outline tooth preparation for FS

• tooth must be plaque free and free from debris

• use a rubber cup/ bristle brush with pumice or any non-fluoride, non-oil based paste to clean the surface

• thoroughly wash and dry tooth to prepare for acid etching

outline enamel etching for FS

• cover the fissure pattern with etch - aim to etch a greater area than the area that will be covered by FS

• wait 30s and aspirate and wash the etch

• dry the tooth - the enamel must appear frosted/ chalky

what substance is used for acid etching

phosphoric acid [37%]

how does acid etch work

• etch slightly demineralises the enamel surface, creating porosities that the FS can flow into

if the tooth becomes wet via saliva contamination after the etching procedure, what should be done

re-etch but for a shorter period of 10-15s (you can tell if acid etching has not worked if the enamel is not chalky)

outline FS application

• place sealant into pits and fissures

  • can soak up with cotton pledgets if too much FS is dispensed

• lightly run a probe through the sealant to eliminate air bubbles

• light cure for 20s to set

• check margins with a probe

• check occlusion with articulating paper

• high spots can be adjusted with finishing burs in a high-speed handpiece

outline FS maintenance

• fissure sealants should be assessed at recurrent dental visits

• check for any loss of material (plaque retentive factor) and discolouration around the edges or under the sealant

what are common ways FS fail

• debonding

• fracture

• adhesive failure - poor moisture control upon placement

  • adhesive failures tend to be immediate

• porosities - may develop due to water contaminants during placement

• heavy occlusal contacts

• caries