OBJECTIVE: To evaluate the filling quality of single cone obturation in root canal model with irregular structure (Hus&Kim Ⅴ, Yin Ⅱ-type isthmus) which established by 3D printing technology using slices and radiographic methods, in order to provide reference for clinical practice. METHODS: (1) Extracted fresh premolars with Hus&Kim Ⅴ and Yin-type Ⅱ isthmus were collected and scanned by cone-beam computed tomography (CBCT), then standard root canal models were designed and printed. Rhodamine B staining and bias fitting were used to verify the availability of the models. (2) 30 root canal models were randomly divided into 3 groups according to different filling methods (n=10). CONTROL GROUP: vertical compaction obturation; Experimental group 1: single cone obturation with 0.06-taper cone (30#); Experimental group 2: single cone obturation with 0.04-taper cone (35#), GuttaFlow 2 as canal sealers. Slices were taken at 2, 4, 6, and 8 mm from the root apex in the direction perpendicular to the long axis of the root and observed under a stereomicroscope to calculate the percentage of filling area (PAV), percentage of gutta-percha-filled area (PGFA), percentage of sealer filled area (PSFA). (3) On the basis of the above results, two groups (n=4) were selected to further analyze the filling quality by micro-computed tomography (Micro-CT), the filling volume of main root canal and the isthmus were obtained, and the percentage of filling volume (PFV) was calculated. Two-way ANOVA was used to evaluate the differences between the groups, and Tukey' s multiple comparison was used to compare the data between the groups and within the groups. RESULTS: (1) Rhodamine B staining solution could overflow the apical foramen, and the main root canal system and the isthmus area were stained, showed no remnants of support material. The 3D standard deviation of the printed model data was 0.03 mm, and the average fitting distance was 0.02 mm. (2) The PFA of the two experimental groups were both significantly lower than that of the control group (F=45.04, P < 0.01). There was no statistical difference of the PFA at apical 2 and 4 mm between the two experimental groups (P>0.01), but at the middle and coronal portions of the root canal (6, 8 mm), the PFA of the experimental group 1 was higher than that of the experimental group 2 (P < 0.01). PFA in the apical 2, 4 mm of the two experimental groups were both lower than that in the middle and coronal portions 6, 8 mm of the canal (P < 0.01). There was no difference in the PGFA and PSFA between the two experimental groups at the apical 2, 4 mm (F=2.383, P>0.01). (3) The results of Micro-CT showed that the PFV of the experimental group 1 was statistically different with the control group (F=47.33, P < 0.01). The PFV of the experimental group 1 was 54.33%±4.35% in the isthmus and 78.31%±4.21% in the main root canal, which were both lower than the PFV of the control group of 76.48%±4.89% (isthmus) and 86.90%±3.29% (main root canal, P < 0.01). The PFV of the main root canal in the experimental group 1 was higher than that in the isthmus (P < 0.01), while there was no difference between the isthmus and the main root canal in the control group (P>0.01). CONCLUSION In the irregular root canal structure with isthmus, using large-taper gutta-percha can improve the filling quality of the middle and upper part of the canal, but the percentage of filling volume in the isthmus is lower than that of the main canal, and more technical improvements are needed.
Humans ; Root Canal Obturation/methods* ; Cone-Beam Computed Tomography ; Root Canal Filling Materials ; Dental Pulp Cavity/diagnostic imaging* ; Printing, Three-Dimensional ; In Vitro Techniques ; Gutta-Percha ; Bicuspid

OBJECTIVES: We aimed to compare the apical sealing properties of three endodontic sealers, namely, C-Root SP (C-R), iRoot SP, and GuttaFlow Bioseal (GFB) in vitro. METHODS: Eighty-two single-rooted premolars and anterior teeth were prepared by using M3 machine with nickel-titanium file and randomly divided into six experimental groups (n=12) and two control groups (n=5). Group A1: single-cone technique (SC)+C-R; group B1: SC+iRoot SP; group C1: SC+GFB; group A2: single-cone with ultrasonic activation (SU)+C-R; group B2: SU+iRoot SP; group C2: SU +GFB; group D: positive control group, and group E: negative control group. Dye penetration length and lateral root canal filling in each group were measured by dye penetration test. A scanning electron microscope (SEM) was used to observe the interface between gutta pertscha, root canal sealer, and dentin wall. Dye penetration length was measured and analyzed by Kruskal-Wallis test, and data on lateral root canal filling were evaluated using Chi-square. RESULTS: The dye penetration length in group A1 was lower than that in groups C1 and A2 (P<0.05) but was not significantly different from the other groups (P>0.05). Lateral root canal filling was not significantly different among all groups (P>0.05). SEM showed that GFB was slightly better than C-R and iRoot SP in binding to gutta pertcha and dentin wall. CONCLUSIONS GFB, C-R, and iRoot SP demonstrate excellent apical sealing ability. Under the conditions tested in this study, SU did not yield significantly improve the apical sealing ability of the three root canal sealers.
Root Canal Filling Materials/chemistry* ; Humans ; Gutta-Percha ; Microscopy, Electron, Scanning ; Root Canal Obturation/methods* ; Ceramics ; Dimethylpolysiloxanes ; Drug Combinations

OBJECTIVES: This study aimed to evaluate the filling effects of three biomaterial root canal sealers [iRoot SP, C-Root SP, and GuttaFlow Bioseal (GFB)] by using Micro-CT. METHODS: Sixty single-canal detached premolars were selected. After crown amputation, their uniform working length was set at 12 mm and prepared to a 06 taper 30# with M3 nickel-titanium file. The samples were randomly divided into six groups with different sealers and obturation techniques: iRoot SP+single-cone technique (SC), C-Root SP+SC, GFB+SC, iRoot SP+single cone-mediated ultrasonic technique (SU), C-Root SP+SU, and GFB+SU. Samples were scanned by Micro-CT, and the total and segmented filling rates were calculated with Mimics 22.0 software after 3D reconstruction. RESULTS: The overall filling rate of the three biomaterial root canal sealers was higher than 90%. The overall and coronal third and middle third segment filling rate of groups iRoot SP+SC, C-Root SP+SC was higher than that of group GFB+SC (P<0.01), with no significant difference between groups iRoot SP+SC and C-Root SP+SC (P>0.05). On the apical third, no significant difference was found among each group (P>0.05). The overall and segment filling rate of groups iRoot SP+SU and C-Root SP+SU was higher than that of GFB+SU (P<0.01), with no significant difference between groups iRoot SP+SU and C-Root SP+SU (P>0.05). The filling rate of the apical 1/3 of group C-Root+SC was lower than that of group C-Root+SU (P<0.01), and the filling rate of the coronal 1/3 of group GFB+SC was higher than that in the GFB+SU (P<0.01). Nevertheless, no significant difference was found in other filling rate of two obturation techniques (P>0.05). CONCLUSIONS The overall filling rate of the three biomaterial root canal sealers using SC and SU are satisfactory. iRoot SP and C-Root SP have similar filling rates, which are significantly higher than that of GFB. C-Root SP combined with SU technique can improve the filling quality of the root apical.
Root Canal Filling Materials ; X-Ray Microtomography ; Humans ; Root Canal Obturation/methods* ; Gutta-Percha ; Dimethylpolysiloxanes ; Drug Combinations ; Dental Pulp Cavity/diagnostic imaging* ; Bicuspid

Compared with cold lateral condensation and continuous wave of condensation which are classically used in clinical, newly emerging single-cone obturation technique is easy-to-operate as well as time-saving. Especially when combined with bioceramic root canal sealers of improved physicochemical and biological properties, single-cone obturation technique showed satisfactory short-term outcomes in clinical observations. However, difficulties still exist in avoiding the root canal overfilling and in operating the retreatment. Besides, the long-term effects of single-cone obturation with bioceramic sealers still remain unclear. This article makes an overview on the history and development of single-cone obturation ,and provides analysis of its pros and corns. Furthermore, we would also like to summarize its clinical application and look into its future improvements.
Epoxy Resins/chemistry* ; Gutta-Percha/chemistry* ; Retreatment ; Root Canal Filling Materials/therapeutic use* ; Root Canal Obturation/methods* ; Root Canal Therapy

OBJECTIVES: The aims of this study were to quantify tug-back by measuring the pulling force and investigate the correlation of clinical tug-back pulling force with in vitro gutta-percha (GP) cone adaptation score using micro-computed tomography (µCT). MATERIALS AND METHODS: Twenty-eight roots from human single-rooted teeth were divided into 2 groups. In the ProTaper Next (PTN) group, root canals were prepared with PTN, and in the ProFile (PF) group, root canals were prepared using PF (n = 14). The degree of tug-back was scored after selecting taper-matched GP cones. A novel method using a spring balance was designed to quantify the tug-back by measuring the pulling force. The correlation between tug-back scores, pulling force, and percentage of the gutta-percha occupied area (pGPOA) within apical 3 mm was investigated using µCT. The data were analyzed using Pearson's correlation analysis, one-way analysis of variance (ANOVA) and Tukey's test. RESULTS: Specimens with a strong tug-back had a mean pulling force of 1.24 N (range, 0.15–1.70 N). This study showed a positive correlation between tug-back score, pulling force, and pGPOA. However, there was no significant difference in these factors between the PTN and PF groups. Regardless of the groups, pGPOA and pulling force were significantly higher in the specimens with a higher tug-back score (p < 0.05). CONCLUSIONS: The degree of subjective tug-back was a definitive determinant for master cone adaptation in the root canal. The use of the tug-back scoring system and pulling force allows the interpretation of subjective tug-back in a more objective and quantitative manner.
Dental Pulp Cavity ; Gutta-Percha ; Humans ; In Vitro Techniques ; Methods ; Root Canal Obturation ; Tooth ; X-Ray Microtomography

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA-PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.
Aluminum Compounds ; therapeutic use ; Calcification, Physiologic ; physiology ; Calcium Compounds ; therapeutic use ; Crystallization ; Dental Pulp Cavity ; microbiology ; Dentin ; microbiology ; Drug Combinations ; Enterococcus faecalis ; ultrastructure ; Humans ; Methylmethacrylates ; therapeutic use ; Microscopy, Electron, Scanning ; Oxides ; therapeutic use ; Root Canal Filling Materials ; therapeutic use ; Root Canal Obturation ; methods ; Root Canal Preparation ; instrumentation ; Silicates ; therapeutic use ; Time Factors ; Zinc Oxide-Eugenol Cement ; therapeutic use

Mineral trioxide aggregate (MTA) is considered at the present time as the gold standard for root-end filling in endodontic surgery. However, this biocompatible material presents several drawbacks such as a long setting time and handling difficulties. The aim of this article is to present a new commercialized calcium silicate-based material named Biodentine with physical improved properties compared to MTA in a clinical application. Two endodontic microsurgeries were performed by using specific armamentarium (microsurgical instrumentation, ultrasonic tips) under high-power magnification with an operatory microscope. Biodentine was used as a root-end filling in order to seal the root canal system. The two cases were considered completely healed at 1 year and were followed for one more year. The 2-year follow-up consolidated the previous observation with absence of clinical symptoms and radiographic evidence of regeneration of the periapical tissues.
Calcium Compounds ; therapeutic use ; Female ; Follow-Up Studies ; Humans ; Microsurgery ; instrumentation ; Middle Aged ; Periapical Diseases ; therapy ; Periapical Tissue ; diagnostic imaging ; physiology ; Radiography, Bitewing ; Regeneration ; physiology ; Retrograde Obturation ; methods ; Root Canal Filling Materials ; therapeutic use ; Root Canal Preparation ; instrumentation ; Silicates ; therapeutic use ; Ultrasonic Surgical Procedures ; instrumentation ; Wound Healing ; physiology

This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation because of difficulty in negotiating all canals. Periapical radiographs and cone-beam computed tomography (CBCT) were taken. All roots were connected and fused to one root, and all canals seemed to be connected to form an O-shape. The apical 3 mm of the root were resected and retrograde filled with resin-modified glass ionomer. Intentional replantation as an alternative treatment could be considered in a maxillary first molar having an unusual O-shaped root.
Adult ; Anatomic Variation ; Apicoectomy ; methods ; Cone-Beam Computed Tomography ; methods ; Dental Pulp Cavity ; diagnostic imaging ; pathology ; Glass Ionomer Cements ; therapeutic use ; Humans ; Male ; Maxilla ; Molar ; diagnostic imaging ; pathology ; Periapical Periodontitis ; therapy ; Retrograde Obturation ; methods ; Root Canal Filling Materials ; therapeutic use ; Root Canal Preparation ; methods ; Tooth Replantation ; methods

One-step apexification using mineral trioxide aggregate (MTA) has been reported as an alternative treatment modality with more benefits than the use of long-term calcium hydroxide for teeth with open apex. However, orthograde placement of MTA is a challenging procedure in terms of length control. This case series describes the sequence of events following apical extrusion of MTA into the periapical area during a one-step apexification procedure for maxillary central incisor with an infected immature apex. Detailed long-term observation revealed complete resolution of the periapical radiolucent lesion around the extruded MTA. These cases revealed that direct contact with MTA had no negative effects on healing of the periapical tissues. However, intentional MTA overfilling into the periapical lesion is not to be recommended.
Adolescent ; Adult ; Aluminum Compounds ; adverse effects ; Apexification ; methods ; Calcium Compounds ; adverse effects ; Dental Fistula ; therapy ; Dental Pulp Necrosis ; therapy ; Drug Combinations ; Female ; Follow-Up Studies ; Foreign Bodies ; etiology ; Gutta-Percha ; therapeutic use ; Humans ; Incisor ; pathology ; Longitudinal Studies ; Male ; Oxides ; adverse effects ; Periapical Abscess ; therapy ; Root Canal Filling Materials ; adverse effects ; Root Canal Obturation ; adverse effects ; Root Canal Preparation ; methods ; Silicates ; adverse effects ; Tooth Apex ; pathology ; Treatment Outcome ; Wound Healing ; physiology

The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scanning electron microscopy (SEM). Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials: (i) white-colored MTA (WMTA), (ii) etched WMTA (EWMTA), (iii) gray-colored MTA (GMTA) and (iv) etched GMTA (EGMTA). After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the Kruskal-Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of (0.007 1±0.004) mm(3), (0.053±0.002) mm(3), (0.003 6±0.001) mm(3) and (0.005 9±0.002) mm(3) respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be (492.3±13.8) µm, (594.5±17.12) µm, (543.1±15.33) µm and (910.7±26.2) µm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found (P<0.05). No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA.
Acid Etching, Dental ; methods ; Aluminum Compounds ; chemistry ; Apicoectomy ; methods ; Calcium Compounds ; chemistry ; Dental Bonding ; Dental Marginal Adaptation ; Dental Pulp Cavity ; ultrastructure ; Dentin ; ultrastructure ; Drug Combinations ; Humans ; Materials Testing ; Microscopy, Electron, Scanning ; Oxides ; chemistry ; Retrograde Obturation ; methods ; Root Canal Filling Materials ; chemistry ; Root Canal Preparation ; instrumentation ; methods ; Silicates ; chemistry ; Surface Properties ; Time Factors ; Tooth Apex ; ultrastructure ; X-Ray Microtomography