ICP-17 Occlusal and Approx Cavity Prep of PRIMARY TEETH Flashcards
Why should we restore children’s teeth
- Eradicate disease and restore health
- To give child simplest form of treatment - easier to accept that pulpotomy or extraction
- Prevent pain and suffering
- Avoid infection
- Maintain arch length - presence space needed for eruption of permanent teeth
- Restore function
- Psychological benefits
- Quality of life
What are the differences between primary and permanent molars
- Primary = thinner enamel
- Primary = greater thickness of dentin over pulpal wall at the occlusal fossa
- Primary = higher pulpal horns, especially mesially, pulp chambers are proportionately larger
- Primary = more pronounced cervical ridges, especially on the buccal aspect of the first primary molars
- Enamel rods at cervix slope occlusal instead of gingivally
- Primary molars have a markedly constricted neck
- Roots of primary teeth = longer and more slender compared to crown size
- roots of primary molars flare out near the cervix
What must be taken into account when taking the decision to restore a child’s tooth
- developmental stage of child
- Caries risk assessment
- oral hygiene
- Parent compliance
- Child compliance
Name some restorative materials that can be used to restore primary molar teeth
- Composite
- GIC
- RMGIC
- Compomers (Polyacid modified composite resin)
- Stainless steel crowns (SSCs)
What are the advantages of choosing composite resin when restoring deciduous teeth
- Aesthetics
- Minimally invasive
- Can be used for PRRs/Fissure sealants/occlusal/small approx. in deciduous molars not extending beyond proxima line
- Approx. in permanent molars no more than one third of buc-lin intercuspal width
What are the disadvantages of choosing composite resin when restoring deciduous teeth
- Polymerisation shrinkage can occur
- Need good isolation/patient cooperation
- Technique sensitive and more time consuming to place
- Not suitable for large multiple surface restorations in posterior primary teeth
What are the advantages of choosing GIC when restoring deciduous teeth
- Chemical bonding to enamel and dentine
- thermal expansion similar to tooth
- biocompatibility
- uptake and release of fluoride
- less moisture sensitivity compared to resin composite
- Good for a shit ton of thing like: luting cement SSC, repainting restorations, cavity base and liner etc
What are the disadvantages of choosing GIC when restoring deciduous teeth
- Not as wear resistant as resin composite
- Not as good aesthetics as resin composite
- RMGIC has better wear resistance
What are the advantages of choosing SSCs when restoring deciduous teeth
- Durable
- Relatively inexpensive
- Minimal sensitivity
- Full coronal coverage
- good for hypo plastic teeth/extensive caries/Hall Tech/multiple lesions
What are the disadvantages of choosing SSCs when restoring deciduous teeth
Aesthetics
What are the considerations that you need to make in cavity preparations
- Risk of pulpal exposure as pulpal horns are higher in primary teeth
- Buccal and lingual wall should be parallel to the outer tooth surface
- Isthmus width should be 1/3 the intercuspal distance
- No bevel at the gingival rest
What is an isthmus
Central portion of the cavity preparation on the occlusal surface of a bicuspid or molar
Where is the isthmus found in a class I preparation
This is located between the mesial and distal dovetails
Where is the isthmus found in a class II preparation
This is located between two proximal flares or one proximal flare and dovetail
What are some important point to remember when preparing occlusal cavity
- Preserved marginal ridge
- Isthmus width 1/3rd of intercuspal distance
- Outline form of isthmus showing smooth flowing curves including all pits and fissures
