ZINCOXIDE EUGENOL Department Of Conservative and Endodontics Dentistry

INTRODUCTION • Used since 1890’s • In general they are cements of low strength,

CONTINUED……. . • Usually dispensed in the form of powder and liquid or sometimes

CLASSIFICATION • Acc. to ADA specification no. 30, Type 1 zoe : Temporary cementation.

COMPOSITION Powder Zn. O : 69% (principle ingredient) white rosin : 29. 3%(reduces brittleness

• Liquid Euginol : 85% (reacts with zno) Olive oil : 15% (plasticizer)

SETTING REACTION • In 1 st reaction hydrolysis of Zn. O to its hydroxide

PROPERTIES • Mechanical properties: 1) COMPRESSIVE STRENGTH, Relatively weak cements. RANGES FROM 3 TO

FACTORS AFFECTING SETTING TIME • Complete reaction takes about 12 hrs. • PARTICLE SIZE

CONTINUED…. • THERMAL CONDUCTIVITY: 3. 98 * 10 -4 / OC SOLUBILITY : 0.

MANIPULATION • P/L RATIO : 4: 1 TO 6: 1 BY wt. • Bottles

MODIFIED ZOE CEMENTS • Introduced to improve mechanical properties of Zo. E cements. •

MODIFIED ZOE CEMENTS • COMPOSITION : POWDER Zn. O → 70% , ALUMINA→ 30%.

MANIPULATION • Glass slabs are recommended. • After dispensing, the powder is incorporated into

POLYMER REINFORCED ZOE CEMENTS • USES : As luting agents, as bases, temporary filling

PROPERTIES • • COMPRESSIVE STRENGTH → 48 MPa TENSILE STRENGTH → 4. 1 MPa

MANIPULATION • Proper powder and liquid is dispensed on the glass slab. • The

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ZINC-OXIDE EUGENOL Department Of Conservative and Endodontics Dentistry Explorer

INTRODUCTION • Used since 1890’s • In general they are cements of low strength, least irritating of all dental cements and have sedative effect on exposed dentin. • To improve strenght many modified zoe have been introduced ; eg, eba –alumina modified and polymer- reinforced zoe cements. • Also non- euginol zinc oxide cements are now available for patients who are sensitive to euginol Dentistry Explorer

CONTINUED……. . • Usually dispensed in the form of powder and liquid or sometimes as two paste system. • A wide variety of zoe formulations are available for temporary and intermediate restorations, cavity liners, thermalinsulating bases, and temporary and permanent luting cements. • They also serve as root canal sealants and periodontal dressing. Dentistry Explorer

CLASSIFICATION • Acc. to ADA specification no. 30, Type 1 zoe : Temporary cementation. Type 2 zoe : Permanent cementation of restorations outside mouth Type 3 zoe : Temporary restoration and thermalinsulating bases. Type 4 zoe : Cavity liners. Dentistry Explorer

COMPOSITION Powder Zn. O : 69% (principle ingredient) white rosin : 29. 3%(reduces brittleness of set cement) Zn stearate : 1. o % (accelarator, plasticizer) Mg oxide : added in some powders reacts with euginol like Zn. O. Zn acetate : 0. 7% (accelarator, improves strength) Dentistry Explorer

• Liquid Euginol : 85% (reacts with zno) Olive oil : 15% (plasticizer) Setting time : 4 -10 min Dentistry Explorer

SETTING REACTION • In 1 st reaction hydrolysis of Zn. O to its hydroxide takes place. Zno + H 2 O → Zn(OH)2 + 2 HE → Zn. E 2 + 2 H 2 O acid salt (eugenol) (Zn eugenolate) Dentistry Explorer

PROPERTIES • Mechanical properties: 1) COMPRESSIVE STRENGTH, Relatively weak cements. RANGES FROM 3 TO 4 MPa UPTO 50 -55 MPa. 2) TENSILE STRENGTH : RANGES FROM 0. 32 TO 5. 3 MPa. 3) MODULUS OF ELASTICITY : 0. 22 TO 5. 4 GPa Dentistry Explorer

FACTORS AFFECTING SETTING TIME • Complete reaction takes about 12 hrs. • PARTICLE SIZE : Smaller Zn. O particles set faster. • P: L RATIO : higher the ratio, faster the set. • Cooling the mixilg slab slows the setting reaction. Dentistry Explorer

CONTINUED…. • THERMAL CONDUCTIVITY: 3. 98 * 10 -4 / OC SOLUBILITY : 0. 4% wt FILM THICKNESS : 25µm ADHESION : Do not adhere well to enamel and dentin. BIOLOGICAL PROPERTES : p. H : 6. 6 TO 8. O BACTERIOSTATIC PROPERTIES Dentistry Explorer

MANIPULATION • P/L RATIO : 4: 1 TO 6: 1 BY wt. • Bottles are shaken gently. • Measured quantity of p and l isdispensed on cool glass slab. • Powder is incorporated in the liquid in increments and spatulated thoroughly in a circular motion with a stainless steel spatula for 30 secs. • Two paste system : equal lengths of each paste are dispensed and mixed until a uniform mix is obtained. Dentistry Explorer

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MODIFIED ZOE CEMENTS • Introduced to improve mechanical properties of Zo. E cements. • Types : a) EBA- alumina modified cements. b) Polymer reinforced. Dentistry Explorer

MODIFIED ZOE CEMENTS • COMPOSITION : POWDER Zn. O → 70% , ALUMINA→ 30%. LIQUID EBA→ 62. 5% , EUGENOL → 37. 5% • PROPERTIES : COMPRESSIVE STRENGTH : 55 MPa TENSILE STRENGTH : 4. 1 MPa MODULUS OF ELASTICITY : 2. 5 GPa FILM THICKNESS : 25µm SOLUBILITY AND DISINTEGRATION IN WATER : 0. 05% wt. Dentistry Explorer

MANIPULATION • Glass slabs are recommended. • After dispensing, the powder is incorporated into the liquid in bulk and kneaded for 30 secs and then stopped for an additional 60 secs with broad strokes of the spatula to obtain a creamy consistency. • They have long working times. • Setting time : 9. 5 min Dentistry Explorer

POLYMER REINFORCED ZOE CEMENTS • USES : As luting agents, as bases, temporary filling material, cavity liners. • COMPSITION : POWDER Zn. O → 70% LIQUID EUGENOL ACETIC ACID→ACCELARATOR THYMOL → ANTIMICROBIAL • SETTING TIME : 6 TO 10 min Dentistry Explorer

PROPERTIES • • COMPRESSIVE STRENGTH → 48 MPa TENSILE STRENGTH → 4. 1 MPa MODULUS OF ELASTICITY → 2. 5 GPa FILM THICKNESS → 32µm SOLUBILITY AND DISINTEGRATION → 0. 03% PULP RESPONSE IS MODERATE. IMPROVED ABRASION RESISTANCE AND TOUGHNESS. Dentistry Explorer

MANIPULATION • Proper powder and liquid is dispensed on the glass slab. • The powder is incorporated into liquid in small increments • The powder is mixed with vigorous spatulation. • To obtain a smooth , creamy mix. Dentistry Explorer