Effect of the curing cycle on some properties of a polymethylmethacrylate denture base material

Abstract

The properties of a denture base material may be modified by altering both the temperature and the time of heating during the curing cycle. In this study a polymethylmethacrylate denture base containing no crosslinking agent was polymerised using four different curing cycles. The structure of the materials so obtained was investigated by an acid etching technique. The materials were characterized with respect to degree of cure, strength and water sorption. It was concluded that: 1. No correlation was observed between the curing cycles and polymer structure. 2. The curing cycle of 7 h at 70 degrees C plus 1 h at 100 degrees C produced best indentation strength and tensile strength. 3. A correlation was observed between residual monomer, indentation resistance, tensile strength and water sorption. This suggested that residual monomer concentration is the most important parameter in the determination of the properties of the material investigated in this study.

Impregnation with antimicrobials challenge bonding properties and water sorption behaviour of an acrylic liner

“…However, the possibility of leaching residual monomer increases as the water absorption increases. 26 Nevertheless, this polymeric system is suggested to be used for a temporary use with well documented biologically satisfactory characteristics. 11,27 Interestingly, a significant positive correlation between the water uptake measured in this study and the amount of drug leached reported previously was detected for all drugs.…”

Effect of microwave disinfection on physical and mechanical properties of acrylic resins

“…This fact is attributed to differences in the residual monomer levels due to the distinct polymerization cycles, considering that the hardness should establish an inversely proportional relationship with the amount of residual monomer (15).…”

Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles

“…The nature and duration of the conditions to which the molded acrylic resin subjected is described as the polymerization cycle 14,26 . The conventional method of polymerization cycle is a long, slow-temperature water-bath polymerization where the heat-polymerization of acrylic resin is processed for 9 h at 74ºC 26 .…”

“…The conventional method of polymerization cycle is a long, slow-temperature water-bath polymerization where the heat-polymerization of acrylic resin is processed for 9 h at 74ºC 26 . There are also post-polymerization cycles such as terminal boiling at 100ºC for durations of 30 min (short-term) or longer than 1 h (long-term) 10,12,14,32 . Furthermore, it has been reported that total polymerization time shorter than 2 h is widely preferred than the long polymerization cycles 3 .…”

“…Although there has been several reported variations of polymerization temperature and time, the conversion of monomer is not complete and this might result in unreacted, residual monomer in the denture base acrylic resin 2-5,10,12,14,25 . Methyl methacrylate (MMA) was the predominant residual monomer in the acrylic resin 32 .…”