Framework Design; Metal Ceramic Fixed Partial Dentures Flashcards
What is the number one things for failure of FPDs
caries
What three things combined a make an optimal restoration
biologic
mechanical
esthetic
What four things are used in the prevention of restoration wear
minimizing sliding contacts
establish anterior guidance
have opposing contacts in same material
control parafunction
What are two clinical design factors to consider
avoid porcelain to gold contact
occlusal contact at least 1.5mm from metal-porcelain junction
Where should you not put the metal ceramic junction
at the contact
Glass will adhere to clean, gas-free metal if covered with what
adherent oxide and temperature raised where oxide is partially dissolves into the glass
Glass to metal bonding is strain free if and if thesis is the same over the entire temperature range
thermal expansion
Adhesive failure at porcelain-metal interface is caused by what three things
oxide layer missing
contaminated metal
contaminated metal oxide
Possible failure mode for cohesive failure in porcelain
maximun strength
Possible failure mode for cohesive failure in metal oxide
excessive oxidation
Possible failure mode for cohesive in metal
doesn’t happen
What are three advantages of anatomic contour waxing
even thickness of porcelain
smooth transition between metal and porcelain
accurate location of metal/porcelain junction
What two things result in insufficient porcelain thickness
esthetic problems
may be due to under-reduced preparation or excessive metal thickness
What 5 laboratory design factors
even porcelain thickness rounded internal angles 90 degrees metal/porcelain junction porcelain "wrap around" metal thickness at least 0.3mm
