en Restorative Dentistry Restorative Dentistry Original article Original article <div style="text-align: justify;"><span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Background and Aim</span></span></span></span></b><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">:</span></span></span></span></b> <span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana="">Fiber-reinforced composite (FRC) restoration is a relatively new method used to enhance the durability of composite restorations. This study measured the fracture resistance of unsupported enamel in composite restorations reinforced with fiber ribbon in comparison with conventional composite restorations. &nbsp;</span></span></span>&nbsp;</span></span></span><br> <span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Materials and Methods: </span></span></span></span></b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana="">In this in vitro study, 30 freshly extracted sound premolars were randomly divided into three groups (n=10): (I) control group: intact teeth, (II) mesio-occluso-distal (MOD) preparation followed by restoration with Filtek P60 composite, and (III) deep MOD preparation and cusp reduction, followed by reinforcement with Interlig fiber ribbon, and subsequent restoration and cusp coverage with Filtek P60 composite. The teeth were stored in saline for one week. Next, their fracture resistance was measured by a universal testing machine. The load at fracture was recorded in Newtons (N). One-way ANOVA followed by the Tamhane post-hoc test was used to compare the groups (alpha=0.05). </span></span></span>&nbsp;&nbsp;</span></span></span><br> <span style="font-size:13pt"><span style="line-height:105%"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#2e74b5">Results: </span></span></span></span></b><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:" verdana=""><span style="color:#0e101a">Fracture resistance of enamel in both experimental groups was significantly reduced compared to intact teeth (P<0.05). Fracture resistance of enamel in FRC restorations was significantly higher compared to the conventional composite restorations (P<0.05).</span></span></span></span><span style="font-size:9.0pt"><span style="line-height:105%"><span style="font-family:"Verdana",sans-serif"></span></span></span></span></span></span><br> <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">FRC restorations significantly increased the fracture resistance of unsupported enamel compared to the conventional composite restorations under in vitro settings.</span></span></span></div> Composite Resins, Dental Enamel, Dental Materials, Tooth Fractures 184 191 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-617-9&slc_lang=en&sid=1 Golnaz Abbaspour Golnazabbaspour0531@gmail.com 100319475328460015527 100319475328460015527 No Dentist, Private Practice, Tehran, Iran. Negin Barzegar Reyhani barzegarnegin@gmail.com 100319475328460015528 100319475328460015528 No Dentist, Private Practice, Tehran, Iran. Shadab Safarzadeh Khosroshahi shadab.kh@gmail.com 100319475328460015529 100319475328460015529 No Department of Restorative Dentistry, TeMS.C., Islamic Azad University, Tehran, Iran. Shahriar Jalalian shahriar.jalalian@yahoo.com 100319475328460015530 100319475328460015530 Yes Department of Restorative Dentistry, Member of Dental Material Research Center, TeMS.C., Islamic Azad University, Tehran, Iran.