Amalgam Restorations Flashcards
What is a marginal ridge?
Edges of the tooth that deflects food from becoming trapped
What is an embrasure?
The v shaped spaces between adjacent teeth providing a route for food to escape during chewing
What needs to be considered in an amalgam restoration?
Method of retention for material of choice
Prevention of recurrent caries - elimination of micro leakage
Assist remineralisation of tooth tissue
Longevity under occlusal load
Protect tooth from mechanical failure
Aesthetics
What is a class 2 restoration?
Lesions occurring between posterior teeth only (mesial or distal)
What is retention provided by?
Convergent cavity walls
What features can increase retention?
Grooves, channels, slots, bonding,pins
Which bur could be used to create a lot?
Inverted cone bur - gives dovetail/ horse shoe
Groove can head towards dental pulp
What are amalgapins?
Drilling small holes into the dentine - 0.8 diameter, 2mm deep
Retains the amalgam
How are shelves produced?
Layer taken away around the outside of the tooth so amalgam catches on around outside - needs to be 2mm high
What does success of the restoration depend on?
Distribute forces around tooth
Consider directions of forces
Place features where they will resist likely loads
What are the advantages of bonded restorations?
Lower sensitivity
Retention rates exceed that of pins
Less iatrogenic damage
Better restoration survival
What are problems with bonded restorations?
Loss of bond layer - slightly soluble layer
Oxygen inhibition
Weakening of amalgam if more bond used
Adhesion to matrix bond - Vaseline?
Where should you avoid putting pins into the tooth?
Bifurcation, curved roots, thin dentine(lower incisors), pulp
Pin placement
Maximise all other retention Find a flat safe location Mark centre with 1/2 round bur Select drill angle Drill hole Clean Place pin Adjust pin if required
What happens if the pin placement goes wrong?
Pulp - endodontics
Perio - trim surgically if it protrudes or minor oral surgery
