en Prosthodontics Prosthodontics Original article Original article <div style="text-align: justify;"><span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Background and Aim</span></span></span></b><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">:</span></span></span></b> <span style="font-size:9.0pt"><span style="font-family:" verdana="">Hybrid ceramics are gaining popularity for cosmetic dental restorations due to their advantageous mechanical properties and optimal esthetic results. However, the potential effects of bleaching on their color stability are still a subject of interest. This study aimed to assess the effect of bleaching on stained hybrid ceramics in comparison with IPS e.max. </span></span>&nbsp;</span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Materials and Methods: </span></span></span></b><span style="font-size:9.0pt"><span style="font-family:" verdana="">This in vitro study was conducted on 48 specimens fabricated from IPS e.max CAD, Vita Enamic, and Cerasmart (n=16) ceramics. The baseline color coordinates of the specimens were measured by a spectrophotometer. Eight specimens from each ceramic type underwent accelerated aging, and their color coordinates were measured again to calculate the color change (&Delta;E1). The remaining 8 specimens in each ceramic group were immersed in tea solution, and their &Delta;E was calculated (&Delta;E2). Subsequently, all specimens were exposed to 20% carbamide peroxide for 8 hours/day for 10 days, and &Delta;E3 and &Delta;E4 were calculated. Data were analyzed by two-way ANOVA and Tukey&rsquo;s test (alpha=0.05).</span></span>&nbsp;</span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Results: </span></span></span></b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#0e101a">Type of ceramic, type of intervention (aging, immersion in tea solution, bleaching), and their interaction significantly affected the &Delta;E (P=0.0001). The maximum and minimum &Delta;E values were recorded for Cerasmart and IPS e.max ceramic, respectively.</span></span></span><span style="font-size:9.0pt"><span style="font-family:"Verdana",sans-serif"></span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Conclusion:</span></span></span></b> <span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#0e101a">Both accelerated aging and immersion in tea solution caused staining of hybrid ceramics. The minimum &Delta;E after bleaching occurred in aged ceramics. Bleaching of stained ceramics improved their color.</span></span></span></span></span><br> &nbsp;</div> Ceramics, Color, IPS e.max CAD LT, Spectrophotometry, Tooth Bleaching Agents 271 281 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-1603-1&slc_lang=en&sid=1 Zahra Jaberi Ansari zahrajaberiansari@yahoo.com 100319475328460013331 100319475328460013331 No Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iranof Medical Sciences, Tehran, Iran. Azam Valian Avalian14@yahoo.com 100319475328460013332 100319475328460013332 No Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Anahit Afrasiabi Anahit.afrasiabi@yahoo.com 100319475328460013333 100319475328460013333 No Dental Research Center, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Parisa Amdjadi amdjadiparisa@gmail.com 100319475328460013334 100319475328460013334 Yes Department of Dental Biomaterials, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran