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