Dental cements manipulation technique & instrumentsDrg. Hesti Witasari JE, SpKG

Fre

qu

ency

(n

)

Compressive Strength (MPa)

40 50 60 70 80 90

5

4

3

2

1

CEMENT MANIPULATION“20 different experienced dental assistants mixing the same cement”

Success / Failure Factors:

(1)

(2)

Operator

Design Factors

(3)

(4)

(5)

Materials Factors

Intraoral Location Factors

Patient Factors

CE

ME

NT

TH

ICK

NE

SS

(10

0

m)

CRACK

• 110 µm is average and 50-350 is typical.• ≤100 µm is generally considered ideal.

SEALING?

CROWN

TOOTHSTRUCTURE

???

80

70

60

50

40

30

20

10

0

TOOTH

CROWN100

90

Powder LARGEParticleCEMENT THICKNESS: POREErosion

RETENTION?Precipitation

RE

LA

TIV

E S

TR

EN

GT

H (

%)

R2 = 0.910140

20

0

100

80

60y = 100e-0.0598x

0 20 40 60 80 100

POROSITY (%)

Ryskewitsch. J Am Ceram Soc 1953;36:65. (Empirical suggestion σ =σoexp(-nP)where n=4-7 and P=volume fraction porosity.)

The instruments

Zinc Oxide Eugenol The zinc oxide is slowly wetted by the

eugenol Prolonged and vigorous spatulation is

required, especially for a thick mix A powder/liquid ratio of 3:1 or 4:1 must

be used for maximum strength

Zinc Oxide Eugenol

Zinc Phosphate Powder is dispensed and divided into 4-

6 portions Liquid is dispensed according to

manufacturer Mixing is gradual at 15 seconds

intervals for 60-120seconds Large strokes over a large area

Dividing P portionsand dispensing L.

Incremental additionsand stropping.

Mixing Procedure and PrecautionsZinc Phosphate Cement

Chilled glass slaband dispensing P.

Fleck’sMizzy

ZP Cement

Zinc Polycarboxylate The material should be carefully

proportioned and the freshly dispensed components mixed rapidly in 30 to 40 seconds

Mix should be used while it is still glossy The interior of restorations and tooth

surfaces should be clean and free of saliva

Powder and liquid should be store under cool conditions and kept sealed with a stopper

At luting consistency, the recommended powder/liquid ratio is about 1.5:1

Working time: 2,5-3,5 min Setting time: 6-9 min(37ºC)

Mixing Procedure and PrecautionsPolycarboxylate Cement

DispensingP and L.

Folding Pinto L.

A C

DB

E

Stropping.

Glass Ionomer Cement The material should be carefully

proportioned and the freshly dispensed components mixed rapidly in 30 – 40 sec.

Some brands are encapsulated, mechanically mixed, and injected

The powder/liquid ratio for luting is about 1,3 : 1 for the conventional types of glass-ionomers cement

The correct cementing mix is fluid, similar with zinc phosphate

Lining mix is more viscous The restorative mix should have putty-

like consistency and a glossy surface Tooth surfaces should be clean and free

from saliva but not dehydrated Restoration surfaces should be free from

debris and contamination

The cement hardens slowly and should be protected from loss or gain of moisture when set clinically

Restoration margins or filling surfaces should be protected with varnish or light-curing sealant

Setting time for luting : 6-9min Lining : 4-5 min Restorative materials : 3-4 min

Gambar varnish

Thankyou