About composite resins restorations:
Composite resin dental restorations are made up of a mixture of plastic and fine glass particles. Broadly they are of two types – direct or indirect. These are generally small and large fillings, especially in front teeth or the visible parts of teeth; inlays. They easily last at least five years and more. These cost only one-third to twice as much as amalgam, but certainly less than gold.

The fillings or inlay are normally invisible. But the dentist has the option to choose a resin that matches the color of your teeth. This type of dental filling can be completed during one dental visit. An inlay may require two visits. Further, the composite fillings can bond directly to the tooth, making the tooth stronger than it would be with an amalgam filling. These fillings involve very less drilling than the amalgam fillings because your dentist does not have to shape the space as much to hold the filling securely. The bonding process holds the composite resin in the tooth. Indirect composite fillings and inlays are heat-cured, a process that increases their strength. The solid advantage is that composite resin can be easily combined with glass Ionomer to provide the benefits of both materials.

The downside is only the expression of doubt that although composite resins have become stronger and more resistant to wear, it's not clear whether they are strong enough to last as long as amalgam fillings under the pressure of chewing. These fillings take 10 to 20 minutes longer, or sometimes more, to place than amalgam fillings because each thin layer of the filling must be cured, or hardened, using a visible blue light. Indirect fillings and inlays take at least two visits to complete, as it involves dentist takes impressions at the first visit and places the filling or inlay at the second visit. Composite resin materials are available in self- curing two-paste systems and light-curing single-paste systems. Some brands offer several tooth color match selections; whereas, others are supplied in a universal shade. The shade must always be selected before the teeth are allowed to dry because dehydration results in lighter shades. Finally, when it comes to large cavities, composites may not last as long as amalgam fillings.

About ceramic restorations:
These are mostly of porcelain material and find applications as inlays, onlays and crowns. The Ceramics are tooth-colored and more resistant to staining and abrasion than composite resin. Ceramics are stronger and brittle than composite resins. A ceramic inlay or Onlay needs to be substantial to prevent breakage, so the tooth must be reduced in size to make room for the extra bulk.

About glass Ionomer restorations:
These are made up of acrylic and a component of glass called fluoroaluminosilicate. The type are resin-modified or hybrid composite and metal-reinforced. Ionomer find regular use as cementation for gold inlays, but is also used for fillings in front teeth. As filling material, glass Ionomer is typically used in people with a lot of decay in the part of the tooth that extends below the gum (root caries). It is also used for filling baby teeth (sealants) and as a liner for other types of fillings. These do not match the tooth color so esthetically. These do however find more application in fillings for kids’ dentistry when the use of drill is to be avoided. The Glass Ionomer release fluoride, which can help protect the tooth from further decay. Glass Ionomer restorations bond to the tooth, helping prevent leakage around the filling and further dental decay.

About cast gold and gold foil restorations:
These are made of gold alloy and mostly used for inlays, onlays and crowns. These do not corrode and withstand chewing pressures better. These are esthetically far better than the silver fillings, and are far too expensive. But it requires multiple visits to the dental office. It cannot be placed next to the tooth with silver amalgam, as passes electric current making saliva as medium and causing pain in the tooth. This is called "galvanic shock." The gold foil on the other hand is made of pure gold. It is very expensive and requires great skill and attention to details in making. Improper placement of gold foil can result in damage to the pulp or periodontal tissues.