In the face of advanced materials and techniques in dental restoration, restorative fillings may appear as more traditional and rather outdated means of restoring natural teeth. Still, their usefulness is acknowledged on account of their qualities like strength and durability. These qualities do count when filling back teeth, which have to exert the greatest chewing forces.

Some of the common restorative materials used very often are

• Composite: also called white fillings or cosmetic fillings
• Glass ionomers: Fluoride releasing
• Resin ionomers: Combination of composites and glass ionomers
• Amalgams: Also called silver fillings
• Ceramics: porcelain
• Indirect composites
• Metals etc

Factors Involved in the Choice of Restorative Filling

Following factors mainly determine what kind of restorative filling you need to choose:

• Oral and general health of the patient
• Composition of the filling material
• Place and mechanism of filling
• The chewing load on the tooth where filling is needed
• Duration and number of visits needed for restoration

Direct and Indirect Dental Restorations

Direct restorative fillings require a single visit in which the filling is placed immediately into a prepared cavity. The dentist prepares the tooth and places the filling, followed by adjusting the restorative and the job is finished. These fillings include:

• Dental amalgam
• Glass ionomers
• Resin ionomers
• Resin composite fillings

Indirect restoration requires at least two visits. The first visit includes preparation of the tooth and making an impression of the area that is to be restored. In the next visit, the filling (coming from the dental lab) is placed and adjustment is made. Types of fillings include:

• Gold alloys
• Base metal alloys
• Ceramics
• Indirect Composites

Composite Fillings

Composite fillings, also called filled resins , consist of a mixture of glass or quartz (silica) filler placed in a resin medium. As a filling it appears as tooth-colored. Composite fillings exhibit the following properties:

• Good durability
• Resistance to fracture
• Withstanding moderate chewing pressure
• Adhesively holding in cavity
• Making a smaller filling than amalgam
• Requiring longer to be placed than amalgam filling

Glass Ionomers

Glass ionomers are translucent mixtures containing acrylic acids and fine glass powders. These are used in cavity filling, especially cavities found on the root surfaces of teeth.

A little fluoride is released by these fillings which is useful against tooth decay. Since their resistive power is low, they are used in places where chewing load is not very high.

Resin Ionomers

These are also made from glass filler with acrylic acids and acrylic resin. They exhibit low to moderate resistance to fracture. Like glass ionomers, they too are used for small, less-load bearing fillings like those between the teeth.

Amalgam Fillings

Amalgam fillings are the most popular of all restoratives. It is an alloy containing mercury, copper, silver, tin, and a few minor elements. Amalgam fillings can withstand great chewing loads and are also useful in restoring deep fillings below gum line. Some concern has been raised about the mercury content of these fillings but authorities in health (FDA, WHO, and others) have found it to be safe. Their greater popularity rests on several reasons like:

• Durability
• Ease of use
• Greater resistance to wear
• Relatively inexpensive in cost

Gold Alloys

These alloys consist of gold, copper and a few other metals. Together these form a strong and effective filling, crown or a bridge. Their primary use lies in inlays, onlays, crowns and fixed bridges. Gold alloys are known for:

• High resistance to corrosion and tarnishing
• High strength and toughness against wear and fracture
• Requiring the removal of minimum amount of healthy tooth structure
• Feeling gentle to opposing teeth
• A drawback to gold fillings is that their color does not look like natural teeth.

Base Metal Alloys

These are high strength and toughness, non-noble metal alloys having a silver appearance. They show high resistance to corrosion, tarnishing, fracture, and wear. Some people may have allergic sensitivity to base metals. Also, some initial discomfort may be encountered from hot and cold.

Ceramic Materials

Ceramic fillings require a minimum of two visits. These include porcelain, ceramic or glasslike fillings and crowns. These are highly resistant to wear but prone to fracture under stress and on impact.

Indirect Composites

These filling materials are similar to those of direct restoration fillings. Their color is like those of teeth. These fillings do not excessively wear opposing teeth. They show less strength and durability than porcelain or metal restorations. In addition, they wear and discolor relatively easily.