Luting agents – what are they?

In short a luting agent is a mouldable material which cements two faces together. For dentistry, the two surfaces are the tooth and the treatment component. This can be a cavity filling or a inlay. Any of these treatments require dental cement to hold the component or treatment that is being performed. If there was no cement the crown would drop off.

Composition of dental cements

Dental cement is hard but breakable materials and are made by combining two ingredients – a powder and a liquid. The powder is made from a different substances which contain a metal oxide and the most common in New Zealand is a carboxylate formulation.

Less common varieties of dental cement can be composed of resin, phosphate or phenolate.

What should a dental cement do?

The key requirement for a cement is that it sticks the two components together and it must be permanent. People do not want to have to return to the dentist to have maintenance treatment on the same tooth so permanent, solid bonding is an absolute must.

A dentist cement must be mouth-friendly to the flesh or the tooth pulp especially so in the case of the dental pulp in root canal work. This is because the cement comes into contact with the pulp which is the live part of the tooth. Any reaction with the pulp will cause severe discomfort to the patient.

Cement for dentistry should also be repellent to saliva. If the saliva was to cause the cement or liner to break down, then the treatment – the filling or crown would become loose and require further treatment. So saliva resistance is vital.

An increasing requirement for dental cement is that it looks good. Because more people choose cosmetic dental work, an obvious looking cement would destroy the aesthetic impact of the veneer or inlay. As a result the premium cements are translucent and can be had in a range of shades to complement the colour of the tooth.

Lastly dental cementing products must be easy for the dentist to handle. This means that the cement comes in different viscosities – one is good for easy cleaning on veneers while the other has lower viscosity for better flow.


At first glance, dental cements and liners look quite innocuous materials which few people ever think about. Yet for most people they are significant substances which have a major impact on us. If we did not have them, we would not be able to have simple dental work like fillings or elective treatment. Dental cements and liner are certainly important in our modern lives.