Journal of Research in Dental and Maxillofacial Sciences

en Effect of One- and Two-Step Processing Techniques on Flexural Strength of Denture Base Acrylic Resin in Dry and Wet Conditions Prosthodontics Prosthodontics Original article Original article <div> <table align="center" hspace="0" vspace="0"> <tbody> <tr> <td style="padding: 0cm 12px; text-align: justify;" valign="top">Background and Aim: This study compared the flexural strength (FS) of heat-cure acrylic resin following one- and two-step processing techniques in dry and wet conditions.   Materials and Methods: In this in vitro study, 60 acrylic specimens (3×10×65 mm) were fabricated (ISO20795-1) and flasked using a type III dental stone. The specimens were heated to 70°C for one hour and baked for 30 minutes at 100°C. After cooling and polishing, 30 specimens were randomly selected; of which, 15 were stored in 37°C water, and 15 in dry condition for one month. The remaining 30 were flasked again, baked, and divided into two subgroups for storage in dry and wet conditions. The FS of specimens was measured by a universal testing machine. Data were analyzed by one-way ANOVA and Tukey's post-hoc test (α=0.05). Results: The mean FS was 57.5±4.8 MPa and 61.7±4 <a name="_Hlk114138066">MPa</a> for specimens subjected to one-step processing and stored in wet and dry conditions, respectively. These values were 56.6±4 MPa and 64.7±2.9 MPa for specimens subjected to two-step processing and stored in wet and dry conditions, respectively (P<0.05). The difference in FS of specimens stored in dry and wet conditions was significant (P<0.05). Conclusion: The two-step processing technique increased the FS while water storage decreased the FS of acrylic resin. FS of specimens subjected to one-step processing with water storage was slightly higher than that of specimens subjected to two-step processing with water storage. FS experienced a greater reduction following two-step processing in a wet environment compared with one-step processing.  </td> </tr> </tbody> </table> </div> Acrylic Resins, Flexural Strength, Polymethyl Methacrylate 171 178 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-1097-2&slc_lang=en&sid=1 Sarira Mehraban Jahromi sariramehraban@yahoo.com 100319475328460012006 0000000240474396 No Department of Prosthodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Mohammad Alidad Naeeni Mohammadalidadnaeeni@gmail.com 100319475328460012007 0000000279280185 No Faculty of Dentistry, Tehran Medical Science, Islamic Azad University, Tehran, Iran Reza Mostafa Pour rezamost68@yahoo.com 100319475328460012008 0000000175856389 No Department of Prosthodontics, Faculty of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Reza Nahidi r.naidi@iautmu.ac.ir 100319475328460012009 0000000302195668 Yes Department of Prosthodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Ali Kaboudanian Ardestani alikaboudanian@gmail.com 100319475328460012010 0000000316625665 No Department of Prosthodontics, Faculty of Dentistry, Tehran Medical Science Islamic Azad University, Tehran, Iran