Improved wettability of an experimental silicone rubber denture soft lining material

Abstract

The purpose of this study was to improve the wettability of an experimental silicone rubber soft lining material (Sildent) to increase patient comfort. Sildent was modified by the addition of polyalkylene oxide poly(dimethylsiloxane) surfactants. The various surfactants were added directly to the polymeric matrix in the quantities 5, 10, 20% w/w. The surfactants were also added to a one part silicone sealant, which was then painted onto the surface of already cured Sildent. Contact angle measurements were made on samples using a dynamic contact angle analyzer. Results showed that incorporation of surfactants A (Silwet L7600) and B (Silwet L7607) effectively improved the wettability of Sildent. This improvement was still evident after 6 months storage in distilled water at 37 degrees C suggesting retention of the surfactants matrix via physio-chemical bonding. Formulations with surfactants added directly to the matrix showed unacceptable water absorption after 2 months in distilled water. Samples with surfactant charged sealant painted on the surface showed a lower water absorption. In conclusion, Sildent formulations modified with polyalkylene silicone surfactants showed improved wettability compared to unmodified Sildent. Further work is needed to reduce water uptake and determine the effect on key mechanical properties.

An antifungal coating for dental silicones composed of chlorhexidine nanoparticles

“…Contact angle of denture soft lining materials is clinically significant as it is related to retention and patient comfort. 28 For this reason, surface treatments or cleansing agents which increase the contact angle are not considered favourable, as this might negatively affect function. The contact angles of the unmodified and coated silicones (mean 108.58, range 102.3-119.18), were similar to other contact angle measurements of silicone soft lining materials (mean 112.08).…”

Contact angle of unset elastomeric impression materials

“…Polyalkylene oxide surfactants, similar to other surfactants used with PVS materials, contain hydrophilic regions (alkylene oxide) and hydrophobic regions (siloxane). 22 The hydrophobic region of the surfactant allows it to be dispersible in the silicone matrix while the hydrophilic region allows interaction with water. 20 If the surfactant is too low in molecular weight and too hydrophilic, it may diffuse from the impression material into the aqueous phase of the adherent.…”

“…This can result in an initial improvement in wettability. 22 The results of this study demonstrate that the novel surfactants in the modified PVS cause a significant decrease in the contact angle produced with water.…”

“…The surfactants of set PVS impression materials lower the contact angle [19][20][21] and reduce voids in the recovered cast; however, contact angles of unset impression materials are generally greater than those measured against set material. 18,22,23 The surfactant in the PVS impression materials must be allowed time to migrate to the surface to induce the hydrophilicity of the surface. 18 The purpose of this study was to compare the hydrophilicity of 7 different unset elastomeric impression materials throughout their polymerization by measuring their contact angles at 5 different times with 2 adherents (water and saliva).…”

Hydrophilic nano-silica coating agents with platinum and diamond nanoparticles for denture base materials

“…Several studies have therefore focused on modifying the denture base to be hydrophilic to prevent hydrophobic interaction 11,14) . One promising approach is the use of coating materials because these do not change the bulk properties of the denture base material but can modify the surface properties 15,16) . Although a previous study indicated that a silica coating agent can make the denture base material hydrophilic 17) , the durability of the agent has not been clarified.…”