Light curing based resins are extensively used in modern dentistry because they offer advantages, such as the ability to bond to the tooth structure and improved aesthetic characteristics. After polymerisation, there is a significant amount of organic compound residue unbound in the cured material. Post-cure heating of composite resin materials has recently become a popular restorative technique. With indirect composite polymerisation systems, an important perspective is the possibility of using post-polymerisation mechanisms associated with heat, pressure or high light intensity. The aim of this study is to evaluate the in vitro elution of monomers (Bis-GMA, TEGDMA, UDMA, Bis-DMA and Bis-EMA) from one composite resin during two different time periods after different polymerisation methods with high performance liquid chromatography. In the current study, the polymerisation methods affected the monomer release. The Inlay System exhibited the lowest monomer release. Post-cure heat application in autoclave after polymerisation increased the amount of released monomers.