Fixed Prosthodontic Lecture I & Ii

Front 1

What are common reason tooth are loss?

Back 1

-Caries
-Periodontal Disease
-Iatrogenia

Front 2

What are some uncommon reason tooth are loss?

Back 2

-Congenitally missing
-Trauma

Front 3

What are some are general considerations during crown cementation?

Back 3

-What kind of crown do I have?
-Does the crown type impact the cement I select?
-What kind of cement will I use?
-What step procedure will I follow to deliver the all-ceramic crown?

Front 4

The color of the cement will affect final shade, in most cases (T/F)?

Back 4

False: Only if the crown is translucent! (Veneers, Empress)

Front 5

What ceramic material can and can not be etched?

Back 5

-Etchable: Feldspathic porcelains, IPS Empress (Leucite)
-Non-Etchable: Alumina or Ziconia Core

Front 6

What material is etching of Silica based ceramics?

Back 6

-Hydrofluoric acid or Ammonium bifluoride

Front 7

What is the mechanism of Etching of Silica based ceramics?

Back 7

It creates microporosities on the porcelain. After intraoral manipulations during crown seating, restore etched surface with 15 sec. application of 37% phosphoric acid

Front 8

A 7-day delay between etching and silane application does affecting bonding (T/F)

Back 8

False, Doesn't affect bonding

Front 9

What kind of solution is Silan Application?

Back 9

Ethanol soln. of y-methacryloxypropyltrimethoxysilance (MPTS-EtOH)
-Increases the ceramic-resin bond by 20%

Front 10

Silane Application have high bonding to alumina or zirconia and will become more stable over time (T/F)

Back 10

False: Silane application bonding is low for alumina or zirconia and unstable over time.

Front 11

What type of bond occur between ceramics and silane coupling agent?

Back 11

Siloxane bond

Front 12

What type of resin luting cements would you use for All ceramic crown?

Back 12

-BIS-GMA resin and other methacrylates = modified composites
-Panavia 21
-Dual cure is recommended. Easy to clean up
-Powder-liquid, Paste-Paste consistencies

Front 13

What kind of system is Panavia 21?

Back 13

-Two-paste system
-Bis-GMA resin and silanated quartz fillers
-Phosphonate molecules very sensitive to O2, it reacts w/ Ca of tooth
-Required air barrier coating (at margins) to allow full set of cement

Front 14

What type of adhesion to enamel does Panavia 21 utilized?

Back 14

-Micromechanical interlocking of resin to the hydroxyapatite crystals and rods of etched enamel
-Strength of enamel to composite bond: 40-60 MPA

Front 15

___ sec application of etchant produces a zone of demineralized dentin (hybrid layer) of _____ micron and opens _____ nm channels around the collagen fibers.

Back 15

-15 sec
-2-5 microns
-20-30 nm

Front 16

What is the primer used for Adhesion to Dentin?

Back 16

HEMA or 4-META in multiple coats

Front 17

What are some things that can be done on Alumina/Zirconia Cores?

Back 17

-Can't be etched
-Silanation provides little benefit
-Sandblast w/ 50 microns Al2O3 (micro-mechanical retention)
-Bond strength about 22 MPA
-Bonding of cement to core material DOES NOT occur

Front 18

List the steps for the crown placement from beginging?

Back 18

-Inspect intaglio surface of crown
-Check crown on the die for accuracy of fit
-Remove provisional crown and remove temporary cement from prep.
-Seat crown, if not seated, Adjust Proximal contacts
-Mark Proximal contact w/ Accufilm II and adjust marked proximal area

Front 19

What instrument is used to adjust proximal contacts on all ceramic crown?

Back 19

Busch Silent Stone or Al2O3 stone

Front 20

What is done to verify internal "fit"?

Back 20

-All ceramic crown will fit loosely compare to other crowns
-Use Black GC Fit Checker
-Adjust w/ diamond and high speed w/ water

Front 21

What keeps the loosely fitting All ceramic crown stable while you're trying to adjust the occlusion?

Back 21

-Consider cementing the crown in place w/ GC Fit Checker wile occluding

Front 22

What is used to polish all ceramic crown and porcelain?

Back 22

Polish w/ Dilate procelain polishing kit, or characterize and re-glaze.

Front 23

When you plan to characterize the crown, what step should be take with adjacent teeth?

Back 23

Keep adjacent teeth moist with water or saliva or staining liquid, to prevent desiccation and color change

Front 24

What is used of Trial cements?

Back 24

Used to confirm final appearance

Front 25

What step is taken to clean the crown before placement into pt?

Back 25

Place crown in Acetone in Ultrasonic cleaner

Front 26

What you can do if pt. lost their provisonal and gingival tissue have grown over the prep?

Back 26

-Retract tissues w/ cords and possibly use LA to minimize trauma to pt.

Front 27

What is the steps that need to be done right before cementation of tooth?

Back 27

-Place thin Mylar Strip
-Etch tooth with 37% Phosphoric acid (20 seconds)
-Rinse and lightly dry and apply bonding agent (Don't dessicate tooth)
-Apply Dual cement and tack in place with small curing tip
-Before full curing remove gross XS and floss proximal
-Cure Cement completely
-Remove XS w/ 30-fluted finishing bur and use Scalpel # 12 to remove interproximal XS
-Polish intraorally any ares requiring polishing

Front 28

What are some reasons for Post-cementation Sensitivity?

Back 28

-Ass. w/ freshly prepped/etched prepared dentin
-Remnants of etching acid
-Low PH of certain cements
-Increase L/P ratio of glass-ionomer cements
-Over-etching, desiccation and collapse of dentinal tubules

Front 29

Can you temporarily cement All-ceramic crowns?

Back 29

-Usually no
-If so, don't use cement containing eugenol as it inhibits polymerization of the resin
-If eugenol cement was used, etching w/ 37% phosphoric acid after cleaning with pumice, may be best way to remove ZOE.