e. Precautions. The following precautions should be observed.
(1) Do not insert glass ionomer cement as a ball of material into deep
cavities or where the dentin is thin or where there is danger of pulpal involvement. In
these cases, set a calcium hydroxide liner in place before inserting the glass ionomer
There may be an allergic reaction to the glass ionomer cement in some
(3) Upon contact with eyes, the powder may cause irritation due to foreign
body reaction. Similarly, ingestion of the liquid may cause local irritation.
(4) All enamel, dentin, and metal surfaces must be clean and dry before use
of glass ionomer cement.
(5) Do not overfill the crown. Brush a thin coat of glass ionomer cement on
(6) Bottles of liquid or powder should be tightly closed after use to prevent
1-19. CHARACTERISTICS OF ZINC OXIDE AND EUGENOL
a. General. This material is used for many dental purposes ranging from
temporary restorative material to pulp capping. The material is composed of a powder
that is basically zinc oxide and a liquid that is called eugenol. Cavitec, a commercial
preparation, is an example of zinc oxide and eugenol. Generally, however, a generic
form is used in military dental clinics.
b. Chemical Composition. By National Bureau of Standards specifications, the
powder must contain between 70 and 100 percent zinc oxide. The manufacturer may
add hydrogenated resins to increase strength and zinc acetate to hasten the set.
Eugenol is usually derived from oil of cloves. The oil of cloves contains more eugenol
(82 percent) than do the oils of bay, orange, or cinnamon. Eugenol is an obtundent
(pain-relieving agent). It is a clear liquid that gradually changes to amber when exposed
c. Physical Properties. This material relieves pain, makes tissue less sensitive
to pain, is slightly antiseptic, and is low in thermal conductivity. It provides a good
marginal seal when placed in tooth cavities. The crushing strength (compression
strength) of pure zinc oxide and eugenol is about 2,000 psi, which is low in comparison
to other cements. The addition of hydrogenated resin increases the crushing strength
to 5,000 psi.