According to its purpose filling materials are divided into: For permanent filling:

• Cements

• Amalgams

• Composites

• Compomers

For temporary filling and dressing:

• Dentine paste

• Artificial dentine

For linings:

• Isolating

• Curative

For root canal fillings.

Dental fissure sealants.

Cements – dental filling materials, composed of powder and liquid.

Cements (D. S. Smith, 1995):

• Phosphate (Zinc-phosphatic, Silico-phosphatic, Silicate)

• Phenol (Zinc-eugenol, Ca(OH)₂-salycylatic)

• Polycarboxylate (Zinc-polycarboxylate, Glass-ionomer)

• Acrylic (Polymetacrylic, Dimethylacrilic)

Chemical composition of dental cements

Powder	Liquid
	Phosphoric acid	Polyacrylic acid
Zinc oxide	Zinc-phosphate cement	Zinc-polycarboxylate cement
Zinc oxide + Aluminum-silicate glass	Silico-phosphate cement	------------
Aluminum-silicate glass	Silicate cement	Glass-ionomer cement

Phosphate-based cements

Zinc-phosphate cements («Phosphate-cement» («VladMiVa», Russia); «Uniphas» («VladMiVa», Russia); «Adhesor» («Spofa Dental», Chesh Republic); «Zn Phosphate» («PSP Dental», Great Britain).)

Composition:

• powder – zinc oxide (75-90%), magnesium oxide (5-13%), silicone oxide (0,05-5%);

• liquid –water solution of phosphoric acid (45-64%), aluminum (2-3%), zinc (0-9%).

Advantages:

• low toxicity;

• thermoisolation properties;

• factor of thermal expansion is similar to factor of thermal expansion of enamel and dentine;

• plasticity;

• easy to work;

• hardens fast.

Disadvantages:

• low mechanical strenth;

• absence of antibacterial effect;

• fragility;

• weak adhesion to enamel and dentine;

• solubility in oral fluids.

Indications for use:

• isolating lining for pulp protection in deciduous and permanent teeth;

• permanent fillings in deciduous teeth at stage of root resorption;

• long-lasting temporary fillings (1-2 months).

Mixing: 2 parts of powder + 3 drops of liquid

Mixing is performed at smooth surface of glass plate with metal spatula. Powder is divided into 4 equal parts (1/4), than 1/4 part is divided into 2 parts (1/8) and 1/8 part is also divided into 2 parts (1/16). Then we mix all the parts (1/4, 1/4, 1/4. 1/8, 1/16, 1/16) are mixed with liquid for 45-60 seconds to formation of homogenous mass. Correctly mixed zinc-phosphate cement does not stick to the spatula. When we take off spatula from cement mass it forms strings of 1 mm in length. If cement mass is too tight we can’t add liquid, we must mix new portion of cement. Working time – 2-3 minutes. Modeling of filling or isolating liner must be less than 1 minute. Time of hardening – 7-9 minutes in the oral cavity.

Silicate cements («Silicyn», «Silicyn–2» («Medpolymer», Russia); «Belacyn» («VladMiVa»; Russia); «Fritex» («Spofa Dental», Chesh Republic); «Silicap» («Vivadent»).)

Composition:

• powder - aluminosilicate glass (silicon oxide - 29-47%, aluminum oxide - 15-35%, calcium oxide - 0,27-14%, sodium fluoride - 5-15%);

• liquid – solution of the phosphoric acid, containing aluminum, zinc and magnesium phosphate.

Advantages:

• mechanical strength is better than those of zinc-phosphate cements;

• factor of thermal expansion is similar to factor of thermal expansion of enamel and dentine;

• plasticity;

• anti-carious action;

• satisfactory esthetics.

Disadvantages:

• weak adhesion;

• not sufficient mechanical strength;

• fragility;

• solubility in oral fluids;

• significant shrinkage during hardening;

• high toxicity to pulp (because of high acidity of cement mass after mixing (pH=1,6) which lasts for 24 hours) that’s why they can be used only with isolating liners;

• not contrast at X-ray.