Tabriz University of Medical Sciences Journal of Dental Research, Dental Clinics, Dental Prospects 2008-210X 15 2 2021 05 25 Reinforcement effect of intra-orifice barrier materials in teeth treated with regenerative endodontic procedure: Research article 111 114 10.34172/joddd.2021.019 EN Sevinç Aktemur Türker https://orcid.org/0000-0001-8740-2480 Keziban Olcay Sena Kaşıkçı Fatma Zühal Yurdagül Journal Article 10.34172/joddd.2021.019 2020 08 11 2020 12 15 Background. Regenerative endodontic treatment (RET) is a clinically advanced procedure for necrotic immature teeth. However, root canal walls of these teeth are brittle especially in the cervical region and need reinforcement. This in vitro study is conducted to evaluate the effect of intra-orifice barrier materials on the fracture resistance of immature teeth treated with regenerative procedure. Methods. Forty-eight maxillary central incisors were used. Twelve intact teeth were selected for the control group. Remained teeth were prepared using peeso drills to simulate immature teeth and assigned into three groups according to the intra-orifice barrier material placed over MTA (n=12); Composite resin (CR), ProRoot MTA and Resin-modified glass ionomer cement (RMGIC). Fracture strength test was applied using a universal testing machine. One-way ANOVA and Tukey post hoc tests were used at P=0.05. Results. A significant difference was obtained among groups (P<0.05). MTA showed the lowest fracture resistance (P<0.05). However, no significant difference was found among RMGIC, CR, and control groups (P>0.05). Conclusion. Intra-orifice restorative materials have reinforcement affect in immature teeth treated with regenerative endodontic procedure. RMGIC or CR can be regarded as a viable choice to reduce the occurrence of cervical root fracture of immature teeth treated with a regenerative therapy.