The effect of nonionic surfactants on bubble entrapment in elastomeric impression materials

Area of Science:

• Materials Science
• Polymer Chemistry
• Dental Materials

Background:

• Silicone and polysulfide elastomers are widely used in dentistry for impression taking.
• Bubble entrapment in casts made from these elastomers can compromise accuracy.
• Improving the wettability of elastomers by casting materials like gypsum is desirable.

Purpose of the Study:

• To investigate the effect of nonionic surfactants on the wettability of silicone and polysulfide elastomers by gypsum products.
• To determine if surfactant addition reduces bubble entrapment in poured casts.
• To assess the impact of surfactants on elastomer properties such as working time, dimensional accuracy, and permanent deformation.

Main Methods:

• Incorporation of various nonionic surfactants into silicone and polysulfide elastomer formulations.
• Evaluation of elastomer wettability using gypsum products.
• Assessment of bubble entrapment in casts poured from treated elastomers.
• Measurement of working time, dimensional accuracy, and permanent deformation of the elastomers after surfactant addition.

Main Results:

• Nonionic surfactants significantly increased the wettability of both silicone and polysulfide elastomers by gypsum.
• Surfactant addition led to a noticeable reduction in bubble entrapment in poured casts.
• The effectiveness of surfactants varied between elastomer types and even brands.
• Rinsing the impression prior to pouring did not diminish the beneficial effect of the optimal surfactant.
• Surfactant addition increased the working time of silicone elastomers but had minimal effect on polysulfide elastomers.
• Dimensional accuracy and permanent deformation remained unaffected by surfactant incorporation in both elastomer types.

Conclusions:

• Nonionic surfactants are effective in enhancing the wettability of dental elastomers by gypsum, thereby reducing casting defects.
• Careful selection of the appropriate surfactant is critical for optimizing performance with specific elastomer types and brands.
• Surfactant treatment offers a viable method to improve cast quality without negatively impacting the essential physical properties of the elastomers.