dental cement dental material

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DENTAL CEMENTS 2014

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Dental cement dental material

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Page 1: Dental cement dental material

DENTAL CEMENTS

2014

Page 2: Dental cement dental material

CementsSubstances used to glue 2 solid objects together

2014

Page 3: Dental cement dental material

2014

In addition to the gluing function,

Dental Cements own many different applications

Page 4: Dental cement dental material

2014

3 main Categories

Page 5: Dental cement dental material

2014

Zinc Oxide

Alumino Silicate Glass

Phosphoric Acid Polyacrylic Acid

Eugenol

ZOE & Ca(OH)2

Zinc Polycarboxylate

Glass IonomerSilicate

Zinc Phosphate

Cements set via Acid-Base Rx

Page 6: Dental cement dental material

ZINC OXIDE EUGENOL (ZOE) CEMENT

2014

Page 7: Dental cement dental material

2014

Presentation forms

Powder Liquid

• Zinc oxide• Magnesium oxide• Zinc Acetate- Accelerator

• Eugenol• Olive oils• Acetic acid- Accelerator

Two paste system(Base & Catalyst)

Eugenol-Containing

Eugenol-Free

Single paste – sets in contact with water

Page 8: Dental cement dental material

2014

How it sets? via acid-base Rx (Chelation)

• ZnO + H2O Zn(OH)2 (1) • Zn(OH)2 + E Zinc Eugenolate (2)

Mixingon either paper pad or glass slab using a stainless steel spatula at high P/L ratio (4 :1)•Thin mix for temp. cementation •Thick mix for temp. filling

Set materialMatrix of zinc eugenolate (chelate) + Dispersed non-reacted Zinc oxide particles

• Presence of water is essential – Saliva could help• Zinc acetate dissolves faster in water zinc hydroxide

Page 9: Dental cement dental material

2014

Controllin

g the Rx sp

eed (setting time)

1. ↓ Powder p

article siz

e

reaction

2. Temperature

reaction

3. Acce

lerators

reaction

4. P/L ra

tio

re

action

5. M

ixing rate (sp

eed or time)

re

action

Page 10: Dental cement dental material

2014

1. Biological Characteristics• Bacteriostatic -- kills bacteria of carious cavities• Low thermal diffusivity -- insulate thermal and electrical irritations• Obtundent effect -- reduces the pulpal pain• High sealing ability -- minimize the leakage in temp. restored cavities

Material’s Characteristics (BMIECP)

Page 11: Dental cement dental material

2014

2. Mechanical Characteristics• Weak cement -- could not withstand either masticatory forces -- could not withstand amalgam’s condensation forces

4. Esthetic Characteristics• Opaque – not used to lute translucent ceramic restorations

3. Interfacial Characteristics• Mechanically-retained -- to both tooth and restorations’ surfaces -- adapt well to cavity walls

Page 12: Dental cement dental material

2014

5. Chemical Characteristics• Water soluable -- dissolves in oral saliva

• Eluted Eugenol -- changes the color of overlying composite restoratives -- retard the polymerization of overlying composite restoratives -- swallowed E causes gastric troubles

6. Practicability• Easily mixed – no special precautions but – it is better to mix it in thick consistency

Page 13: Dental cement dental material

2014

Applications

1. Temporary cementation

2

. Temporary filling

3. Cavity

liner

4. In

direct p

ulp capping

5. Endodontic sealer

6. Surgical packs

Page 14: Dental cement dental material

2014

Modified Materials

Page 15: Dental cement dental material

2014

CALCIUM HYDROXIDE

Page 16: Dental cement dental material

2014

Presentation forms

Ca(OH)2 powder

Single paste – methyl cellulose- sets in air

Light-cured Ca(OH)2 paste – resin matrix

Two paste -- the only sets via an acid-base Rx

Base Catalyst

• Calcium hydroxide• Zinc oxide• Zinc Acetate- Accelerator• Liquid vehicle

• di-salicylate, • Radio-opacifers,• Fillers

Page 17: Dental cement dental material

2014

1. Biological Characteristics --- related to material’s alkalinity (pH= 11-13)• Bacteriostatic -- kills bacteria of carious cavities• Neutralizes the acids produced by the cariogenic bacteria• Help differentiate pulpal stem cells -- reparative dentin stimulator

Material’s Characteristics (BMIECP)

2. Mechanical Characteristics• Weak cement -- could not withstand amalgam’s condensation forces

4. Esthetic Characteristics• Opaque – not used to lute translucent ceramic restorations

3. Interfacial Characteristics• Mechanically-retained -- does not adhere to the tooth structure

5. Chemical Characteristics• Quite soluble -- dissolves in liquids even under leaked restorations

Page 18: Dental cement dental material

2014

Applications

1. Dire

ct & indire

ct pulp ca

pping 4

. temp. endodontic fi

lling

2. Cavity

liner

5

. Temporary cementation

2. Endodontic s

ealer

6. pulpotomy

Page 19: Dental cement dental material

2014

ZINC PHOSPHATE CEMENT

Page 20: Dental cement dental material

2014

Powder Liquid

• Zinc oxide• Magnesium oxide• Other oxides &

fluorides

• Phosphoric acid (H3PO4)• Water (30-40%)• Buffering agents -- Zinc oxide, zinc

hydroxide

Presentation forms

Mixingon thick, cool glass slab using stainless steel spatula powder is added to the liquid in small incrementsMixing over a wide area•Thin mix for cementation •Thick mix for cavity base /temp. filling

Page 21: Dental cement dental material

2014

How it sets? Through a Fast , exothermic acid-base Rx (Crystallisation)

ZnO + H3PO4 Zn3(Po4)2 + H2O

Set material matrix of zinc phosphate salt+ dispersed non-reacted zinc oxide particles

Controlling the Rx speed (setting time)1. ↓ Powder particle size reaction2. Temperature reaction3. ↓ Buffers reaction4. P/L ratio reaction5. Mixing rate (speed or time) reaction6. Acid concentration reaction

Page 22: Dental cement dental material

2014

1. Biological Characteristics• Pulp irritant -- fresh mix is highly acidic (pH 1.6-3.6) -- Ca(OH)2 liner is needed in deep cavities -- Thin mix is more irritant than the thick mix -- Set material becomes neutral in 48 hrs• Low thermal diffusivity -- insulate thermal and electrical irritations

Material’s Characteristics (BMIECP)

2. Mechanical Characteritics• Stronger than ZOE and weaker than GI -- withstand amalgam’s condensation forces (cavity bases)-- could withstand masticatory forces ( permanent cementation /temp filling)

3. Interfacial Characteristics• Mechanically-retained -- to both tooth and restorations’ surfaces• Film thickness similar to that of zinc phosphate cement (15μm)

Page 23: Dental cement dental material

4. Esthetic Characteristics• Opaque – not used to lute translucent ceramic restorations

5. Chemical Characteristics• Water soluble -- dissolves in oral saliva -- thin mix dissolves more than the thick mix

2014

6. Practicability• Material is successfully used for a long time• Needs well-trained operator due to its short S.T.• precautions –

1. Liquid bottle should be tightly closed all the time2. Liquid with cloudy appearance should be discarded3. Shake the powder bottle before dispensing the correct ratio 4. never use powder of other cements (e.g. ZOE…) or of other manufacturer

Page 24: Dental cement dental material

2014

Applications

1. Final cementation

2.Cavity base

3. Temporary filling

4

. Cementation of orthodontic bands

5. Dentin building-up

Page 25: Dental cement dental material

2014

POLY-ACARYLIC ACID

in comparison to phosphoric acid•Has lower acidity •Has higher molecular weight --More viscous•Bonds chemically to the inorganic part of tooth structure

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2014

ZINC POLYCARBOXYLATE CEMENT

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2014

1. Powder Liquid

• Zinc oxide• Magnesium oxide• Flourides

• Poly-acrylic acid (30-40%)• Water

2. Powder in a single bottle

water settable material

Freeze dried acid is blended with the powder

3. Capsules

Presentation forms

Page 28: Dental cement dental material

2014

MixingOn a glass slab using stainless steel spatulaPAA is viscous and needs more effort during material’s mixing •Thin mix ( P/L ratio 1.5:1) for cementation •Thick mix ( P/L ratio 2.5:1) for cavity base /temp. filling

How it sets? Through a acid-base Rx

ZnO + PAA Zn-polyacarylate + H2O

Set material matrix of zinc polyacrylate salt+ dispersed non-reacted zinc oxide particles

Page 29: Dental cement dental material

2014

Controllin

g the Rx speed (setting time)

1. ↓ Powder p

article size

reaction

2. Temperature

reaction

3. P/L ratio

reaction

4. Mixing rate (sp

eed or time)

reaction

5. Acid concentra

tion

reaction

Page 30: Dental cement dental material

2014

1. Biological Characteristics• Pulp irritant -- fresh mix is acidic But less than zinc phosphate cement is -- Ca(OH)2 liner is needed in deep cavities -- Thin mix is more irritant than the thick one -- Set material becomes neutral in 48 hrs• Low thermal diffusivity -- insulate thermal and electrical irritations

Material’s Characteristics (BMIECP)

2. Mechanical Characteristics• Its strength is comparable to that of zinc phosphate cement-- withstand amalgam’s condensation forces (cavity bases)-- could withstand masticatory forces ( permanent cementation /temp filling)

3. Interfacial Characteristics• Chemically adhere -- to the tooth and base metal restorations• Film thickness similar to that of zinc phosphate cement (15μm)

Page 31: Dental cement dental material

2014

4. Esthetic Characteristics• Opaque – not used to lute translucent ceramic restorations

5. Chemical Characteristics• More soluble in water than zinc phosphate cement -- thin mix dissolves more than the thick mix

6. Practicability• Viscous liquid make the mixing process a little pit difficult• All metallic instruments should be cleaned up while the cement still unset• To achieve better bonding

1. Tooth surface should be cleaned and dried from saliva

2. Mixed cement should be applied to tooth structure as fresh as possible

Page 32: Dental cement dental material

2014

Applications

1. Final cementation

2.Cavity base

3. Temporary filling

4

. Cementation of orthodontic bands

5. Dentin building-up

Page 33: Dental cement dental material

2014