framework and pontic design

Question 1

what thickness is needed to avoid fracture on ceramic veneer? whats the min. for esthetic reasons?

Answer 1

2mm, 1mm.

Question 2

at what rate does enamel ware?

Answer 2

10 micrometers a year

Question 3

why is it a good idea to have metal on the lingual surface of maxillary incicors?

Answer 3

it wears less than ceramic against the natural teeth.

Question 4

what should you keep in mind while restoring opposing teeth?

Answer 4

contacting surfaces must be the same material, like ceramic opposing ceramic.

Question 5

what must you analyze before placing a pontic?

Answer 5

mesiodistal width, occlusocervical width, buccolingual width, and edentulous ridge area.

Question 6

what are biological considerations for successful pontic design

Answer 6

easy to clease, can access abutment teeth easily, no pressure on ridge

Question 7

what are esthetic considerations for successful pontic design?

Answer 7

shape of a tooth, appears to “grow” out of edentulous ridge, sufficient space for porcelain

Question 8

what are mechanical considerations fo successful pontic design?

Answer 8

rigid, strong connectors, metal ceramic framewor( to resist fracture)

Question 9

residual ridge ideal

Answer 9

smooth regular surface of attached gingiva, good height and width, no freenum attachment

Question 10

what would a loos in residual ridge result in?

Answer 10

open gingival embrasures and food compaction.

Question 11

pontic designs are classified into 2 general groups….

Answer 11

those that contact the oral mucosa and those that dont.

Question 12

selection mainly depends on …

Answer 12

esthetics and oral hygiene.
Anterior: pontic adapted to tissue, emerging from gingiva.
Posterior: less esthetic but amenable to oral hygiene.

Question 13

name the 5 pontics

Answer 13

Sanitary/Hygienic pontic
Saddle/Ridge Lap pontic
Modified Ridge Lap pontic
Conical pontic
Ovate pontic

Question 14

advantages and disadvantages of sanitary/hygienic pontic

Answer 14

A: easy cleaning
D: entrapment of food, may lead to tongue habits

Question 15

advantages and disadvantages of saddle/ridge lap ponitc

Answer 15

A: concave shape that overlaps ridge simulating emergence
D: not accessible to clean which leads to plaque and tissue inflammation.

( SAD=BAD)

Question 16

advantages and disadvantages of modified ridge lap pontic

Answer 16

A:combines best features of saddle and hygenic pontics, good esthetics and easy cleaning, overlaps ridge on facial side but not on lingual,( gingival surface must have no depressions), Most common pontic for visible teeth.

Question 17

advantages and disadvantages for conical pontic

Answer 17

AKA: egg, bullet, or heart shaped
A: easy cleaning,
Should be as convex as possible with only one contact at center of ridge, Most commonly used in mandibular incicors where esthetics is less important.

Question 18

advantages and disadvantages ovate pontic

Answer 18

A: esthetics and strength
D: meticulous hygiene required, surgical tissue management and cost.

most esthetically appealing, its convex surface is placed in a tissue depression on the ridge which appears as emergence. This also needs socket-preservation to create the tissue depression.