DENTAL COMPOSITE FILLING MATERIALS AS A POTENTIAL RISK OF TOXICITY FOR HUMAN ORGANISM

Overview

Introduction, aim: Composite materials used in dentistry are increasingly used for several reasons – aesthetics, hypersensitivity of some individuals to amalgam and concerns about the possible release of amalgam metals, and at the same time limiting its use due to the negative impact on the environment both during production and disposal. Composite materials consist of monomers, filler, polymerization initiation system and other substances that improve the properties of the filler. After application to the cavity, the filler material solidifies by a polymerization process which is initiated chemically, by light or dual. The conversion of monomers used in dentistry will never reach 100%, which is one of the weaknesses of these materials. Upon contact of the composite materials with water, alcohol as well as an acidic environment, it has been found that some components, such as non-polymerized monomers, can be gradually released from the composite. In the oral cavity, composite fillings are exposed to the constant action of saliva as well as food and beverages, which affect the release of composite components. They can cause local allergic reactions, but they can also affect the whole human body by swallowing saliva-containing monomers.

Methods: In this work, the amount of unpolymerized monomers released from selected composite materials, prepared in the shape of a cylinder with a height of approx. 2 mm and diameter of 3 mm, weighing approximately 0.05 g and cured – polymerised according to the procedure specified by the manufacturer, was determined. Subsequently, the composites were immersed in unstimulated saliva at 37 °C and the amount of monomers released was determined at several time intervals. A high performance liquid chromatography with a UV detector was used for saliva analysis. The amount of monomers released into saliva over time from the curing of the composite was monitored.

Results: During the elution of monomers from composite fillers into saliva, their amount gradually increases, different monomers leach out at different concentration levels. The largest amount of released monomers was measured from composite materials containing triethylene glycol dimethacrylate, while bisphenol A-glycidyl methacrylate was eluted in the smallest quantity.

Conclusion: Due to the relatively high levels of released monomers, it is important in the development of composite materials to monitor their levels in saliva in the first hours after application as well as in the long term in order to produce a more biologically compatible composite.

Keywords:

composite material – Saliva – monomer release – chromatography