D6138 L-5 1

1.Luting cements a.Permanent & provisional indirect restorations

b.Orthodontic brackets

c. Post and cores

2.Restorative materials a.Permanent and provisional direct restorations

1) Class V restorations

3.Amalgam bonding agents (certain resin cements)

4.Cavity liners & Bases a.Pulp protection

5.Multiple applications a.No one cement can fulfill all requirements

Cement Setting mechanism

Applications

1 2

CaOH Acid-base Pulp cap agent

Liner

Zinc oxide eugenol

ZO non-eugenol Acid-base Temporary luting

Zinc polycarboxylate Acid-base Temporary luting

Zinc phosphate Acid-base Luting agent Base

Glass ionomer (GI) Acid-base Luting agent

Cl V restorations

Liner

Base

Resin-modified GI Acid-base AND polymerization

Luting agent

Class V

Liner

Base

Resin cement Polymerization Luting agent

Adhesive resin cement Polymerization Luting agent Amal bond

1. *Low film thickness (25 m)

2. *Adequate strength (minimum 70 MPa)

3. *Low solubility (0.2% max. @ 24h)

4. *Reasonable setting time (2.5-8.0 min)

5.Adequate working time

6.Biocompatible, not irritate pulp

7.Cariostatic

8.Adhesion to tooth structure and restorative

materials

*ADA and ISO specification requirement

D6138 L-5 2

1. Zinc-oxide eugenol cement

2. Zinc polycarboxylate cement

3. Zinc phosphate cement

4. Glass ionomer cement

5. Resin-modified glass ionomer

6. Resin cement

7. Adhesive resin cement

1. Powder: Zn Oxide; Liquid: Eugenol

a. Sedative, obtundent

2. Temporary cement and restorations

3. ZOE unmodified, TempBond

4. ZOE polymer-reinforced (IRM)

a.Temporary cement: Retention or time

b.Provisional/intermediate restoration

5. Not use prior to resin-based permanent

cement, Why?

1.Temporary cement

2.Eugenol replaced with other oils

3.Used prior to permanent resin-based

cement

4.TempBond NE

a.Slow set

b.Low retention

1. Powder: Zn oxide; Liquid: Polycarboxylic acid/H20

2. Low strength: a. Compressive, 55-67 MPa (ADA spec minimum = 70 MPa)

b. Highly viscoelastic, restoration dislodgement

3.Used as temporary cement

a. Better retention ZO eugenol or non-eugenol provisional cement

b. Chelation interaction: cement COO- & Ca+ tooth surface (Physical interaction + and -)

c. Bond strength: ~1-2 MPa

4. Durelon, Ultra-Temp

a. Can be used prior to resin cement Why?

D6138 L-5 3

1. Powder: Zn Oxide; Liquid: Phosphoric Acid/H2O

2. Low bond strength: micromechanical with

tooth and crown irregularities

a.No chelation interaction

b.Bond strength: 0.5-1.5 MPa

c. Preparation retention and resistance form

critical

3. Luting agent or base

1. Powder: Calcium fluoroaluminosilicate glass

Liquid: Polycarboxylic acid/H2O

2.Fluoride release

3.Bond strength: 3-5 MPa

a.Chelation, cement COO- and Ca+ tooth surface

4.Post-cementation hypersensitivity

a.Early protection (varnish) to prevent hydration and

dehydration of initially set cement

5.Brands: Ketac-Cem, GlassLute

FAS glass (powder)

ZnO (powder)

EUG

Phos acid Poly

acid

Zinc phosphate

cement (‘ZP’)

Zinc polycarboxylate cement (‘ZPC’)

Glass-ionomer cement (‘GI’)

Zinc oxide-eugenol cement (‘ZOE’)

Acid-base cements

Central Concepts in Dental Materials, EC Combe

1. “RMGI”

2. “Hybrid ionomer”

3. “Resin ionomer”

4. Introduced due to limitations of

conventional GI cements

a. Low initial mechanical properties

b. Moisture sensitivity

D6138 L-5 4

1. Powder

a.Fluoroaluminosilicate glass (same as GI)

2. Liquid

a.Polycarboxylic acid/H2O (same as GI)

b.Resin monomers, vary with products

1) HEMA

2) Bis-GMA

3) Replace some of the water of conventional GI

c. Photoactivator (Light-activated only)

1. Acid-base reaction (Conventional GI setting reaction)

Fluoroaluminosilicate glass + Polycarboxylic acids F, Al hydrogel

2. Monomer (methacrylate) polymerization

a. Chemically-activated

b. Light-activated

c. Dual-activated

1. Fluoride release (source?)

2. Low solubility: 0.07-0.40%

3. Bond strength

Material

Bond strength (MPa)

RMGI GI

Dentin *5-10 3-5

Alloy (Rexillium III) 7-12 5-7

All-ceramic (alumina or zirconia)

10-15 3-5

Amalgam core 5-10 3-5

Composite core 10-15 5-7

*Dentin bond agent (DBA) can increase RMGI dentin adhesion. However, DBA use contraindicated: 1) fluoride release 2) add another interface, RMGI/DBA

(Powers & Sakaguchi 06; 3M ESPE)

4. Expansion

a.Water sorption, hydrophilic resin (HEMA)

b.Decreased expansion with new formulations

1) Less HEMA

2) More BisGMA, hydrophobic resin

c. RMGI contraindicated: all-ceramic

restorations

1) Restoration fracture due to luting agent expansion

2) Glass and glass-infiltrated ceramics more prone to

fracture (discuss in later lecture)

D6138 L-5 5

1.Powder/liquid system (2 bottle)

a.Fluff powder

b.Equal number powder scoops &

liquid drops (bottle held vertically)

c. Rely X: crown (3 scoops); bridge (6 scoops) UMKC

d.Powder, liquid mixed within 30s

e.No light activation/chemical only

f. Brands: Rely X (3M ESPE);

Fuji Plus (GC); CX Plus (Shofu)

RelyX vs Vitrebond (liner/base) vs Vitremer (restorative/core) How are they different?

2. Capsulated powder/liquid system

a. Triturate 10 sec

b. No dispensing: less error, faster

c. Less voids than hand-mixed

d. Brands: Fuji Plus (GC)

3. Paste/Paste systems a. 2-tube dispenser

b. Mix on pad

c. Quicker dispensing

d. Less dispensing error

e. Brands:

1) Fuji Cem

2) RelyX Plus

Geristore (DenMat) •Not a luting agent •Liner, base, Class V, root caries, subgingival restorations, retrograde root filling

1. Dispense and mix immediately

a. Prevent water evaporation from liquid

2. Mixing time: 20-30 sec maximum

3. Working time: 2.5 min

4. Apply thin layer inside restoration

5. Seat restoration

a. Tooth should be clean and dry, NOT dessicated

1) Post-op sensitivity

6. Excess cement removed after 3 minutes

a. Difficult to remove later

7. Final set time: 5 minutes

a. If necessary, adjust occlusion and polish

D6138 L-5 6

1. Metal-supported crowns and fixed partial dentures

2. Prefabricated or cast endo posts

3. All-ceramic restorations?

4. Not high bond strength, not appropriate when retention compromised

1. “Poly-acid modified composite”

2. Fluoroaluminosilicate glass

3. Methacrylate monomer

a. Modified with polyacid groups

4. Polymerization rxn only

5. No initial polycarboxylic acid-base rxn

a. Possible later acid-base rxn with water from tooth?

6. NOT resin-modified GI

7. Brand: Principle (Dentsply),

1. Introduced in 1950s: unfilled resin

a. „Resin only‟ problems

1) High polymerization shrinkage

2) High coefficient of thermal expansion (higher than

tooth or crown)

3) Lead to microleakage and restoration failure

2.Current resin cements– late 1980s

1. Unfilled or filled (inorganic/glass filler particles) a. Resin cement vs Resin composite cement

2. Polymerization reactions

a. Light-activated (Light-cure)

b. Chemical-activated (Chemical-, Self-cure)

c. Dual-activated (Dual-cure)

3. Use of dentin bond agent (DBA)

a. Some resin cements do not require DBA 1) RC bonds directly to tooth (Adhesive RC)

b. With some, DBA applied to tooth prior to RC 1) DBA bonds to tooth, resin cement bonds to DBA

(Non-adhesive RC)

D6138 L-5 7

1. Physical bonding: very weak interaction, 2 bonds

2. Chemical bonding: strongest bond, 1 bonds

a. Limited occurrence, usually dissimilar materials

b. Example: composite bond to adhesive bond agent

3. Mechanical bonding:

a. Micromechanical retention

Powers and Sakaguchi 06

1. ZnPO4, GI, RMGI a. Cement locks into microscopic irregularities of

prepared tooth and crown internal surface

b.Additional chelation between Ca+ and COO-: GI, RMGI

1) Physical interaction +/- ions

c. Lower bond strengths

2.Resin cements a. Enamel: resin tags in etched enamel (minimal crown prep)

b. Dentin: hybrid layer

c. Dentin/Cement interface varies ---RC brand

1) Cement not requiring DBA:

a)Resin cement directly bonded to tooth Adhesive RC interface: Tooth/RC/Crown

2)Cement requiring DBA: a) DBA bonded to tooth and RC bonded to DBA

Non-adhesive resin cement interface: Tooth/DBA/RC/Crown (another level added)

3)15-30 MPa bond strength

1. Most of the current resin cements are filled

(resin composite cement)

a. Filler: solubility, polymerization shrinkage,

thermal expansion

2. Current unfilled resin cement:

a. C & B Metabond (Parkell)

D6138 L-5 8

1. Unfilled cement 2. Chemical-activation 3. Composition:

a.Base: 4-META/MMA (4-methyloxy ethyl

trimellitic anhydride/ Methylmethacrylate)

b.Catalyst: TBB (tributyl boron oxide)

c. Powder: Polymethylmethacrylate powder

NO glass filler particles - not a composite

d.Same composition as AmalgamBond

4-META/MMA-TBB Resin Cement C & B Metabond

4. Manipulation

a.Etch, rinse, dry tooth

b.Base/Catalyst/Powder mixed 10-22C

1) Highly exothermic reaction

2) Package warning: spontaneous combustion

5. Application: metal-based restorations

6. Advantages a.Direct bond to tooth, No DBA b.Medium-high strength bond (~17 MPa) c. Use with over-tapered preparations, short axial walls

7.Disadvantages

a.Bond strength NOT long-term:~10 MPa at 1 yr (Kitasako et al 02)

b.Higher solubility (related to bond strength): 1) MMA more soluble than Bis-GMA-based RC

2) No filler, also adds to increased solubility

c. Difficult removal of excess, Technique-sensitive product

8. „Short-term fix‟

a. Initial good bond. Over time, solubility counteracts

4-META/MMA-TBB Resin Cement

1. Basic Description

a.Bis-GMA based resin

b.Filler: Silanated glass, silica particles

c. Polymerization activation

1) Light, Chemical, Dual

d.Brand dependent use of DBA

D6138 L-5 9

1. No dentin bonding agent, RC directly linked

to tooth (Adhesive resin cement)

2. Chemical-activation

3. Composition

a. Bis-type methacrylate/TEGDMA

b. 10 MDP: Phosphate ester, Adhesive monomer for tooth

structure, metal, ceramics

c. Filled ~80 wt%: Silanated filler particles (Barium

glass, Silica)

Panavia 21 available at UMKC

4. Manipulation

a.Self-etching primer: ED primer (Liquid A & B)

1) Apply for 60 sec, then dry. Do not rinse.

2) Acidic HEMA primer: pH ~2-3

3) Do not use conventional phosphoric acid etch

b.Mix catalyst & base pastes, 20 sec 1) Spread thin on pad

2) Prevent premature set

c. Apply to restoration, seat

4. Manipulation

d. Clean excess cement

1) Use microbrushes, gauze

2) Floss to remove interproximal excess

e.Apply Oxyguard to margins & wait ~3-4 minutes

1) Panavia, anaerobic set

2) Oxyguard: prevent oxygen inhibition, chemical activators

included

3) Be sure no excess cement remains before Oxyguard

placement

4) After Oxyguard placement, the cement will set. Once set,

almost impossible to remove excess. Can bond teeth

together.

1.Same system as Panavia 21, except

a.Dual-activated

1) Additional photo-activator, light on margins prior to

Oxyguard

b.Sodium fluoride (fluoride release)

D6138 L-5 10

1. Advantages

a. Low solubility, sorption, expansion

b. High bond strengths

c. Hybrid layer, demineralized dentin + filled resin cement:

Micromechanical union

C: Panavia

D: Dentin

Hybrid layer

(arrows)

2. Disadvantages

a. Expensive

b. Multiple steps

c. Careful with clean-up, difficult to remove

after polymerized

d. Post-operative sensitivity

1) More common prior to self-etching primer (ED

primer)

3. Bond Strength (MPa):

a.Dentin: ~20-25

b.Enamel: ~30-35

c. Ceramics: ~35-40

d.Alloy (Noble and Base): ~35-40

1) High noble alloys: High gold (40%) alloys

(1) Must use Alloy Primer on alloy

(2) NOT Tin plate

Increases Panavia bond

strength to high noble

(gold) alloy

• Added to Panavia kit at UMKC • Kit instructions (NOT CURRENT) indicate Tin Plating • What happens if don’t use?

D6138 L-5 11

4. Applications

a.Metal-based and ceramic restorations

b.Posts, Post-cores

c. Amalgam bonding (directions in lecture

handout)

4. Applications

d. Resin-bonded fixed partial

dentures (“Maryland bridge”)

Bond strength (stress)=Occlusal Force/Bonding Area

1) Reduced bonding area:

Increased stress, higher bond strength required

e. Compromised retention restorations

1) Short, over-tapered crown

(decreased area, decreased resistance form)

4. Applications

e. Compromised retention restorations

2) Long-span, high stress, fixed partial dentures

a) FPD Flexibility length3

Double bridge length, 8x more flexible

i. As number of pontics between abutments increase,

increased flexibility of FPD

ii. Increased potential for restoration/cement breakdown

b) Use high modulus metal (high rigidity)

c) High bond strength cement

1. Resin cements not requiring DBA (Adhesive RC) a. Used for compromised retention

b. Minimal shade options, esthetics not primary consideration

c. Multilink (Ivoclar), RelyX Unicem (3M ESPE), Panavia (Kuraray)

2. Resin cements requiring DBA (majority of RC) a. Often shade options available, esthetic applications

1) Veneers, all-ceramic restorations

b. Calibra (Dentsply), NT Prime & Bond

c. Variolink II (Ivoclar), Syntac

d. RelyX ARC (3M ESPE), Single Bond

e. Many more DBA/RC products

D6138 L-5 12

1. UMKC options:

a. Calibra, NT Prime & Bond

b. Envision, Mirage bond agent

2. Try-in pastes

3. Higher bond strengths with adhesive RC a. No DBA (Adhesive RC)

1) Panavia, RelyX Unicem: ~ 20 MPa

b. DBA RC (esthetic, non-adhesive RC) 1) Variolink II, Calibra: ~ 20 MPa

4. Applications

a. High strength (compromised retention) applications: use Adhesive RC/non-DBA cement

b. Non-compromised retention situations: use DBA RC OR what is another cement option for alloy-based indirect restorations?

5. Cost: all expensive, $15-35/g

Plan to use RMGI or resin cement

What are the temporary cement options?

1. Premature occlusion

2. Pulpitis

3. Loosening of the restoration

4. Recurrent caries

5. Restoration incomplete seating

a.Often linked to other problems

D6138 L-5 13

1. Cement viscosity; Pseudoplasticity

2. Restoration morphology

a.Onlay vs. crown:

less force required

3. Seating force: excess force leads to

dentin rebound and potential restoration

dislodgement

Luting agent Tensile

Strength (MPa)

Solubility (% in 24h)

Dentin/Cement/Crown Bond Strength (MPa)

ZnPO4 5 0.2 max 0.5-1.5

GI 6-7 0.4-1.5 3-5

RMGI 15-25 0.07-0.40 ~5-10

Resin Cement (RC/DBA)

35-40 0.15 ~15-20 (Dentin/DBA/RC/Crown)

Adhesive Resin Cement

35-40 0.15 ~20-30

Luting Agent Strengths Weaknesses Application

ZnPO4

•100 yrs clinical experience

•Inexpensive

•High solubility

•Low Strength

•Routine metal- based restorations

GI •>20 yrs clinical experience

•Moisture sensitivity

•Low early MP

•P-op sensitivity

•Routine metal-based restorations

RMGI

•Medium strength

•Fluoride release

•Low solubility

•Little p-op sens

•Expansion

•Lower bond strength

•Routine metal-based restorations

Resin cements

•20 yrs clinical

experience

•Low solubility

•Good bond qualities

•Multiple steps

•Expensive

•Difficult remove excess

•Occasional p-op sensitivity

•Metal-based, Ceramic

•Lab composites

•Posts, Cores

•Compromised retention

(Adhesive RC)

•Resin-bonded FPD (Adhesive RC)

•Amalgam bonding (Panavia)

25 questions (2 pts each)

Multiple choice, short answer

Review:

Blackboard materials

List of Study Objectives in NOTES files