The evaluation of some properties of a synthetic polymer based root canal filling material and a resin based root canal sealer

THE EVALUATION OF SOME PROPERTIES OF A SYNTHETIC POLYMER BASED ROOT CANAL FILLING MATERIAL AND A RESIN BASED ROOT CANAL SEALERThe purpose of this study is (i) to evaluate the effects of 2% chlorhexidine and 5.25% sodium hypochlorite on the surface properties of Resilon cones with the atomic force microscopy, (ii) to compare gutta percha and Resilon by using two root canal obturation system (System-B Heat Source and Obtura II) on capability to replicate intracanal depressions with split tooth models, (iii) to assess the dentine tubule penetration and dentin wall adaptation of Epiphany root canal filling system with a scanning electron microscopy, (iv) to observe sealer distribution in root canals obturated with Epiphany root canal filling system by three obturation techniques, and (v) to compare the filling capability of Epiphany system and gutta percha on artificial lateral canals by using three obturation techniques.The Resilon cones were immersed in disinfecting agents (5.25% sodium hypochlorite and 2% chlorhexidine) at 1 and 5 min time intervals. Atomic force microscopy was used to evaluate topographical deviations of Resilon cones. Root mean square (RMS) parameters for topographic amplitudes were calculated. The cones exhibited statistically significant low RMS values at 5-min immersion in sodium hypochlorite and chlorhexidine groups compared to the all other groups (p<0.05). One-minute immersion did not show any significant deterioration on the Resilon surface (p>0.05). In conclusion, sodium hypochlorite and chlorhexidine solutions used for disinfection significantly decreased (p<0.05) the RMS values of Resilon cones at 5-min applications.Extracted two human maxillary central incisors were embedded in a clear acrylic resin blocks just below the CEJ. After root canal preparation, 4 artificial defects were created by using round bur on dentinal walls. Split models were obturated with gutta percha and Resilon using by warm vertical compaction (System B Heat Source) and thermoplastic injection technique (Obtura II) for 10 times for each groups. The samples were detected for defect replication and void formation. No statistically significant differences were found between the gutta percha and Resilon in void formation (p>0.05). Twenty five samples obturated with System-B and four samples obturated with Obtura II had voids (p<0.05). Narrow canal split model generated statistically more voids than wide canal split model (p<0.05). Gutta percha was statistically better than Resilon, and likewise wide canal was found better than narrow canal in replication of intracanal defects (p<0.05). No statistically significant differences were found between the System-B and Obtura II groups.Extracted thirty human anterior teeth with uncurved roots were collected and the crowns were seperated at the CEJ with a high speed water-cooled diamond bur. The root canals were instrumented with rotary instruments and divided into three groups. The groups were obturated with Resilon and epiphany by using lateral condensation, warm vertical condensation (System B) and thermoplastic injection technique (Obtura II). The roots were seperated vertically. SEM investigation was performed on Resilon-dentin interface at the medial third and digital images were captured. The dentin tubule penetration and dentin wall adaptation of the Epiphany root canal sealer was evaluated. Warm vertical condensation technique has had the best dentin penetration relative to the other groups.Thirty simulated resin blocks with curved canals were used for this part of the study. The canals were instrumented with rotary instruments and divided into three groups. The groups were obturated with Resilon and Epiphany by using lateral condensation, warm vertical condensation (System B) and thermoplastic injection technique (Obtura II). The resin blocks were sectioned perpendicular to the long axis at 5 mm and 10 mm from the canal orifice and 3 mm from the apex with a water cooled diamond coated saw. The digital images were captured with a digital camera attached to stereomicroscopy from each cross-section samples. The images were transferred to computer and analyzed by using Adobe Photoshop programme and the proportion of sealer to root canal fillings were calculated. Lateral condensation technique showed less root canal filling ratio at coronal section (p<0.05). Obtura II technique showed more sealer at apical third than coronal and medial thirds (p<0.05). System B didn?t show statistically significant differences among the sections. In conclusion, warm vertical condensation exhibited more homogen root canal fillings relative to other groups.Extracted sixty human anterior teeth with uncurved root were collected and the crowns were removed at the CEJ with a high speed water-cooled diamond bur. The root canals were prepared with rotary instruments and lateral canals at coronal, medial and apical thirds of the roots were created artificially and randomly divided into six groups. The groups were obturated with the following techniques; (1) gutta percha Ah Plus by using lateral condensation, (2) gutta percha Ah Plus by using warm vertical condensation, (3) gutta percha Ah Plus by using Obtura II, (4) Resilon and Epiphany by using lateral condensation, (5) Resilon and Epiphany by using warm vertical condensation, (6) Resilon and Epiphany by using Obtura II. The teeth were demineralized with a 5% nitric acid for 72 hours, cleared in methyl salicylate and examined under a stereomicroscope. Accessory canals were evaluated in the apical, middle and coronal thirds of each root canal and the depth of penetration of root filling material and cement into lateral canals was scored using a 5 grade scale. Warm vertical condensation technique showed significantly better penetration at all levels (p<0.05). Gutta percha and Resilon didn?t show any significant difference among the techniques, but significant differences were found at apical thirds.Key Words: Resilon, gutta percha, lateral condensation, System B, Obtura II.