The Influence of Different Obturation Systems on the Fracture Resistance of Endodontically Treated Roots. An in Vitro Study

This study aimed to compare the fracture resistance of endodontically treated roots filled by different obturation systems. Material and methods: Ninety-six upper central incisors were used and decoronated, retaining 12 mm of the roots. On the basis of obturation systems, the roots were divided into 4 groups (n=24): Group1 (COGR): control group (unprepared, unfilled), Group 2 (AVGR): ActiV GP points/ActiV GP sealer, Group3 (GPGR): Gutta percha points/AH plus sealer, and Group4 (GAGR): Gutta percha points/ActiV GP sealer. The last three groups were obturated with the single cone technique. The roots were then stored in 100% relative humidity at 37 °C for 2 weeks. A vertical compressive force was exerted with a universal testing machine until a fracture occurred. Data were statistically analyzed with one-way ANOVA. Results: Mean (SD) failure loads for groups ranged from 920.51 ± 210.37 to 1113.44 ± 489.42 N. The fracture resistance between the different study groups indicated no statistical difference. Conclusions: ActiV GP system did not exert a significant effect on the fracture resistance of endodontically treated teeth

Evaluation of the pulp response following direct pulp capping with exogenous nitric oxide and Mineral Trioxide Aggregate (MTA) a histologic study

Background: Recently, vital pulp therapy is widely used all over the world. It aims to maintain the viability and function of the injured dental pulp tissue. Direct pulp capping is recognized as one of the most common used techniques in this approach. Aim of the study: we aimed to compare the histopathological response of the dental pulp following direct pulp capping using two different capping materials; the exogenous nitric oxide (NOC-18) and Mineral Trioxide Aggregate (MTA) in dogs’ teeth. Methods and materials: The pulp of thirty-two premolars and canines from four dogs (eight teeth per each dog) the pulp was exposed and treated with either exogenous nitric oxide (NOC-18) and MTA (four teeth in each group). The treated teeth were extracted and prepared for histologic evaluation after one month and three months, respectively. The histologic study evaluated the formation of dentine bridge, the degree of pulpitis, calcification of the coronal pulp tissue and odontoblasts layer activity. We have the ethical approval to achieve this research from the scientific committee in Faculty of Dentistry, Damascus University. Results: The results showed that the active statue of odontoblasts layer in NOC-18 group was significantly more than in MTA group after a month of recall (P: 0.003). No significant difference was found between MTA and NOC-18 categories in the formation of dentine bridge after 3 months (P: 1.000). Conclusion: Exogenous nitric oxide (NOC-18) maybe has a positive impact on formation of calcified bridge and efficacy of odontoblasts layer on directly capped dog's teeth. Exogenous NO donors might offer alternative to current pulp capping agents in Vital Pulp Therapy in endodontic

The Influence of Different Obturation Systems on the Fracture Resistance of Endodontically Treated Roots. An in Vitro Study

This study aimed to compare the fracture resistance of endodontically treated roots filled by different obturation systems. Material and methods: Ninety-six upper central incisors were used and decoronated, retaining 12 mm of the roots. On the basis of obturation systems, the roots were divided into 4 groups (n=24): Group1 (COGR): control group (unprepared, unfilled), Group 2 (AVGR): ActiV GP points/ActiV GP sealer, Group3 (GPGR): Gutta percha points/AH plus sealer, and Group4 (GAGR): Gutta percha points/ActiV GP sealer. The last three groups were obturated with the single cone technique. The roots were then stored in 100% relative humidity at 37 °C for 2 weeks. A vertical compressive force was exerted with a universal testing machine until a fracture occurred. Data were statistically analyzed with one-way ANOVA. Results: Mean (SD) failure loads for groups ranged from 920.51 ± 210.37 to 1113.44 ± 489.42 N. The fracture resistance between the different study groups indicated no statistical difference. Conclusions: ActiV GP system did not exert a significant effect on the fracture resistance of endodontically treated teeth