all ceramic restorations

fixed dental prosthesis

the general term for any prosthesis that is securely fixed to a natural tooth or teeth, to one or more dental implants; it CANNOT be removed

examples of fixed dental prosthesis

• partial coverage restoration

• complete crowns

partial coverage restoration

an artificial replacement that restores missing tooth structure by surrounding part of the remaining structure w a material such as cast metal alloy, ceramics, or resin

indications for complete ceramic crowns (4)

• extensive loss of tooth structure

• existing complete crown

• major morphological modification

• significant shade change

types of complete crowns

• complete cast crown

• metal-ceramic crown

• all ceramic crown

advantages of all ceramic restoration

• superior esthetics

• good tissue response

• digital workflow capability

• higher mechanical strength

disadvantages of all ceramic crown

• critical preparation design

• strict bonding protocol

• opposing tooth wear

• brittle nature

indications for all ceramic restorations

• high esthetic requirements

• favorable distribution of occlusal load

contraindications of all ceramic restorations

• more conservative restorations applicable

• unfavorable distribution of occlusal load

how do you define a ceramic dental ceramic

ceramics contain strong, direction, ionic bonds between metals and oxygen that impart strength but will not tolerate distortion

2 phases that dental ceramics are composed of

• glassy phase

• one or more crystalline phases

inc the amount of crystalline phases lead to…

crystalline reinforcement and inc the resistance of crack propagation but also can dec translucent (zirconia)

rank these from inc (low to high) mechanical strength

glassy (feldspathic) → glass-dominated → crystalline-dominated → crystalline

rank these from inc (low to high) optical translucency

crystalline → crystalline- dominated → glass-dominated → glassy (feldspathic)

what is flexural strength

material’s ability to withstand bending forces without breaking or deforming

flexural strength of enamel

80-90 MPa

feldspathic ceramics are porcelains that are composed of primarily….

glassy phase w embedded leucite crystals

properties of feldspathic porcelain (4)

• high translucency

• highly esthetic results

• technique sensitivity

• low flexural strength

restorations that use feldspathic porcelain

• ceramic veneers

• metal-ceramic restorations

glass-dominated ceramics contains…

increased amounts of crystalline phase relativve to the glassy ceramic

crystals in glass-dominated dental ceramics may be ________ or _________

fluroapatite or leucite

leucite-reinforced glass properties

• sufficient translucency

• moderate esthetic results- only one shade so may have ot stain

• less technique sensitivity

• higher flexural strength- 85-112 MPa) than feldspathic

crystalline-dominated ceramics are composed of…

most (70% volume) of crystalline phase

what are the crystals in crystalline dominated ceramics

• spinel (MgAl₂O₄)

• zirconia (ZrO₂)

• alumina (Al₂O₃)

• lithium disilicate

crystalline ceramics are formed from either…

alumina or zirconia that has been doped, w other ions such as Mg or yttrium to optimize them for use in dental applications

zirconia is a ________ material

polymorphic

what are the 3 phases that zirconia can exist in

• monoclinic phase (m)

• tetragonal phase (t)

• cubic phase (c)

what phase is used more dental-wise

tetragonal phase

phases of zirconia are based on

temperature

temp change to get from monoclinic phase to tetragonal phase

1190 degree C

temp change to get from tetragonal phase to cubic phase

2370 degree C

the monoclinic phase of zirconia mechanical properties

exceptional mechanical properties

tetragonal phase of zirconia possesses _________ mechanical properties but…

superior mechanical properties BUT is NOT stable at room temp

how to achieve enhanced strength in zirconia

by incorporation of dopants into the zirconia so that the tetragonal phase is partially stabalized at room temp

two materials you would debate on if you were doing anterior full coverage ceramic crowns

• lithium disilicate

• zirconia

between lithium disilicate and zirconia, which would give you a higher esthetic outcome for anterior full-coverage crowns

lithium disilicate

when comparing the optical properties of lithium disilicate and zirconia, which is more translucent and which is more reflective

• zirconia: more reflective

• lithium disilicate: more translucent

if the anterior tooth substrate color is dark, and your pt wants “hollywood white” which material would you use for a full coverage all ceramic crown

lithium disilicate is still fine

if the anterior tooth has a gold foil on the tooth substrate, what material would you use for a full coverage all ceramic crown

zirconia → would rlly need to mask the gold

when comparing lithium disilicate and zirconia, which use either press or CAD/CAM tehcnique and the other only can use CAD/CAM technique

• zirconia: CAD/CAM

• lithium disilicate: press and CAD/CAM

why can’t you press zirconia

temp is too high

when comparing lithium disilicate and zirconia, which laminated/monolithic

both zirconia and lithium disilicate are laminated/monolithic

what is laminated

high strength core w porcelain- photo shows coping w zirconia and feldspathic layered ontop

laminated technique

uses a layered technique → get higher esthetics → more time consuming

what is monolithic

full contour ceramics w stain; only one material then aid custon shading

when would you lead towards the monolithic technique

posterior teeth for strength

when comparing lithium disilicate and zirconia, which has a higher flexural strength and what are each of the values

• zirconia IS HIGHER: 900-1200 MPa

• lithium disilicate: 215-400 MPa

survival and complications of monolithic single ceramic crowns

monolithic ceramic can be conisdered a favorable tx for single crowns and FPDs, w HIGH survival and LOW complication rates

although an in-vitro study reported that monolithic zirconia presented a high fx resistance than lithium disilicate crowns, ___________ was observed in the survival and complication rates

no difference