Comparative Evaluation of Dimensional Stability of Elastomeric Impression Materials Subjected to Ultraviolet Irradiation and Spray Atomized Disinfection: An In Vitro Study

Aim and background:The study was done to compare and evaluate the linear dimensional stability of three elastomeric impression materials, namely polyether (PE), polyvinyl siloxane (PVS), and polydimethylsiloxane (PDS) after subjecting to ultraviolet (UV) irradiation and spray disinfection techniques.Methods and methodology: Three elastomeric impression materials namely PE (3M ESPE Impregum soft), PVS (Zhermack elite P And P), and PDS (Zhermack Oranwash L and its indurater) of light body consistency were used.Ultraviolet rays and 2.5% chlorhexidine (CHX) gluconate (spray disinfection) were used as disinfectants.A master die was used to create 40 samples from each material.Three parallel lines of equal length were given in the die.A sample was accepted if two or three lines were reproduced continuously and were well-defined.A total of 120 samples were made and subjected to disinfection.Out of the 40 samples from each material, 20 samples were irradiated with UV light of approximately 200-280 nm for 20 minutes and the next 20 from each material were treated with spray atomized disinfection.The sample was sprayed and sealed in a plastic bag for 30 minutes.Measurements of the samples were done.Each line in the sample was evaluated under a stereomicroscope at 10× magnification.The average length of lines in each sample was compared to that in the die.The values obtained in the UV irradiation and spray disinfection were also compared.Results: A statistically significant difference was shown in the dimensional stability of all three elastomeric impression materials subjected to UV irradiation and spray disinfection when compared with that of the die.Polyether demonstrated a statistically significant difference when compared with UV and spray atomized samples whereas PVS and PDS showed dimensional change when compared with the die, but no statistically significant difference was found when samples treated with both the disinfection techniques were compared.Conclusion: Elastomeric impression materials of light body consistency had dimensional change when treated with UV irradiation for 20 minutes and spray atomization with 2.5% CHX gluconate.Clinical significance: Prevention of cross-contamination when handling impression materials without hampering their dimensional stability is mandatory to obtain a successful treatment.