Effect of certain disinfecting solutions and surfactant on the wettability of silicone rubber impression materials

Abstract

Back ground: All dental impressions should be disinfected before pouring to control
cross contamination but disinfection may affect impression wettability. This study
evaluated the effect of disinfection and the use of surfactant agent on the
wettability of some silicone impression materials by contact angle registration of
the gypsum slurry on flat surfaces of the impressions.
Materials and methods: addition silicone regular body –automixing type- and
condensation silicone (light body)with two types of disinfecting solutions 0.2%
chlorhexidine gluconate and 1% povidone iodine for two disinfecting times and
one surfactant agent (soap) were used in this study. Three treatment regimes were
investigated: The first group of impression materials specimens was exposed to
saliva for 5 minutes (control group). Second group of specimens was exposed to
saliva then to disinfectant agents, and third group of specimens was exposed to
saliva, disinfectants and surfactant agent (experimental groups), a computerized
photographic procedure was used to measure the wettability of the specimens.
Statistical analysis was performed by using t-est at p<0.05.
Results: the results revealed that treatment with 0.2% chlorhexidine gluconate as a
disinfectant alone or when tested with the surfactant improved the wettability of
addition and condensation silicones at 30min. disinfection time ,but surfactant
coating of disinfected condensation silicone produced a significant increase of the
mean values at 60min. disinfection time. While treatment with 1% povidone
iodine disinfectant increased the mean contact angles for both addition and
condensation silicones significantly. Same result was seen when povidone iodine
was used in combination with the surfactant.
Conclusion: disinfection with 0.2% chlorhexidine gluconate produced a high-energy
impression surfaces for both addition and condensation silicones.