Amalgam or composite? Making an informed decision when choosing a filling material

Tooth decay is a lengthy multifactorial complex process. To put it simply when risk factors such as rate of acid attack, susceptible tooth surfaces, lack of adequate oral hygiene, specific strains of bacteria and low buffering rate of saliva occur concurrently for a prolonged period of time is when the decay process starts and eventually the tooth ends up with a ‘cavity’.Not all new spots of decay require fillings. For example, a new small spot of decay where the enamel is still intact (i.e. cavitation has not occurred) can be reversed over time given the proper guidance for the patient.Dentists at Dominion Dental Centre pride themselves in taking active preventative measures in these cases such as fluoride treatment, salivary testing, dietary counselling for the patients and routine monitoring of early/new spots of decay and teaching patients proper oral hygiene techniques for the best outcome.

For a tooth that is beyond repair a filling must be placed once the existing decay has been cleaned out. Historically amalgam was the material of choice as a filling material. It is made up of a mixture of elements such as silver, tin, copper and mercury. It is a biologically compatible material which has proven its strength and longevity over many years of use.

The biggest disadvantage of the use of amalgam is the aesthetics, hence it’s use is usually restricted to the posterior dentition. However amalgam is slowly becoming more controversial in recent times, especially when the addition of mercury to the alloy is concerned. The teaching at the Dental School of Otago University states that amalgam is a safe material to use. There have been hundreds and thousands of studies carried out around the world in regards to amalgam safety, specifically exposure to mercury vapour and it’s toxic effects. No published studies from reputable sources have proved amalgam to have detrimental effects on health.In our practice most of our patients choose to have white/composite fillings placed to achieve a better aesthetic result. Composite material is a mixture of plastic and glass, it comes in various shades and differing properties to suit each and every single tooth. Once a composite filling is placed and is shaped like a tooth, further characterisation can be achieved with staining to mimic the natural fissure or grooves of the tooth and can be polished to a high lustre to match that of naturally occurring enamel. At Dominion Dental Centre we use nano-hybrid composites due to it’s high strength and polishability.Composite material has improved vastly in recent years and many studies now show that they can last as long as an amalgam filling provided the operator is

skilled, the characteristics of the patient and the type and location of the damage is favourable. Composites can also be used to alter the shape/form of teeth to achieve a better smile anteriorly. We offer our smile makeover patients both porcelain veneers
and composite bonded veneers and discuss the pros and cons of choosing either option so they can make an informed decision. Composite build ups can also be used for more complex cases, for example where vertical height has been lost due to tooth wear and re-establishing the bite is required. This is achieved by building up every tooth after careful analysis of the patients bite has been carried out.

Dr Sumaya Ershad and Dr Thair Abdul-Hamid routinely attend seminars/courses run by different bodies such as the New Zealand Dental Association and the New Zealand Academy of Cosmetic Dentistry in order to upskill, keep up to date with the latest techniques and gadgets used for the use of composites taught by composite ‘guru’s around the world.