Evaluation of the Trifecta obturating technique

Abstract – The aim of this project was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta‐percha or the Trifecta obturating system. One hundred freshly extracted human mature, single‐rooted teeth were divided into four identical groups of 25 teeth on the basis of root canal shape. The root canals of two groups were prepared in such a way as to produce a relatively parallel canal shape with little or no flare towards the coronal orifice. The root canals of the other two groups were prepared in such a way as to produce a canal shape that was deliberately more flared to ensure that they were wider at the orifice than at the endpoint of the preparation. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one flared and one parallel group were obturated using cold lateral condensation and the canals of the other two groups were obturated using the Trifecta system. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a 4‐point scale. Canals filled with thermoplasticised gutta‐percha had significantly less apical dye penetration than those obturated by lateral condensation (P<0.001). Lateral condensation achieved significantly better scores for radiographic quality than thermoplasticised gutta‐percha from both the bucco‐lingual (P<0.001) and the mesio‐distal views (P<0.001). Root canals obturated using the Trifecta technique showed significantly more apical extrusion of sealer than those obturated by lateral condensation (P<0.001). Under laboratory conditions the Trifecta technique had better sealability but poorer radiographic quality than lateral condensation.     

A technique for obturating palatal fistulas

Use of nontoxic self-adhesive material is described to obturate residual hard palate fistulas. This material may be used during perceptual and aerodynamic speech assessments to evaluate speech distortion and the relative contributions of velopharyngeal port and fistula to nasal air leakage during speech. It may also be used as an interim obturator prior to surgical repair of a fistula.     

Comparison of cold lateral condensation and a warm multiphase gutta-percha technique for obturating curved root canals

AIM: The aim of this project was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta-percha or multiphase gutta-percha obturation (Alphaseal). METHODOLOGY: A total of 108 freshly extracted human, mature single-rooted teeth were divided into two identical groups of 54 teeth on the basis of root canal shape. The canals were prepared to a minimum 0.055 taper and enlarged to size 35 at the apex. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one group were obturated using cold lateral condensation of gutta-percha and the canals of the other group were filled using a warm multiphase gutta-percha obturation technique. The extrusion of sealer and/or gutta-percha through the apex of the teeth was recorded using a simple yes/no scheme. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a four-point scale. RESULTS: Root canals filled by multiphase obturation had significantly more extrusion of sealer (P < 0.001) and gutta-percha (P < 0.001) than canals filled by lateral condensation. Canals filled by multiphase gutta-percha obturation had significantly less apical dye leakage than those obturated by lateral condensation (P < 0.05). Lateral condensation achieved significantly better scores for radiographic quality than multiphase obturation from the bucco-lingual view (P < 0.01). CONCLUSIONS: Under laboratory conditions multiphase gutta-percha had better sealability but poorer radiographic quality than lateral condensation.     

Comparison of different techniques for obturating experimental internal resorptive cavities

Abstract – Forty extracted maxillary central incisors were instrumented at the working length to a #50 file. The roots were sectioned transversely with a diamond disk at 7 mm from the anatomical apex. At the opening of the root canal of each section, hemi‐circular cavities were drilled with a specially designed bur. The corresponding root sections were cemented with glue, thus obtaining root canals with similar cavities that simulated internal resorptions. Teeth were embedded in plaster casts to facilitate their handling. The specimens were randomly separated into four groups of 10. The following obturation techniques were evaluated: lateral compaction (group A), hybrid technique (group B), Obtura II (group C), and Thermafil (group D). AH26 was used as the sealer. After obturation, the plaster was removed and the teeth were radiographed in buccolingual and mesiodistal directions to evaluate the quality of the obturation at the IRC. The incisors were then cut with a scalpel at the same level as the previous section, to examine, under a stereomicroscope, the type of material that filled the IRC. Obtura II gave the best results and in most of the specimens obturated with this technique, the IRC were filled mainly with gutta‐percha. Statistical analysis of the data indicated that the differences between group C and the other groups were significant (P<0.05).     

Comparison of different techniques for obturating experimental internal resorptive cavities

Forty extracted maxillary central incisors were instrumented at the working length to a #50 file. The roots were sectioned transversely with a diamond disk at 7 mm from the anatomical apex. At the opening of the root canal of each section, hemicircular cavities were drilled with a specially designed bur. The corresponding root sections were cemented with glue, thus obtaining root canals with similar cavities that simulated internal resorptions. Teeth were embedded in plaster casts to facilitate their handling. The specimens were randomly separated into four groups of 10. The following obturation techniques were evaluated: lateral compaction (group A), hybrid technique (group B), Obtura II (group C), and Thermafil (group D). AH26 was used as the sealer. After obturation, the plaster was removed and the teeth were radiographed in buccolingual and mesiodistal directions to evaluate the quality of the obturation at the IRC. The incisors were then cut with a scalpel at the same level as the previous section, to examine, under a stereomicroscope, the type of material that filled the IRC. Obtura II gave the best results and in most of the specimens obturated with this technique, the IRC were filled mainly with gutta-percha. Statistical analysis of the data indicated that the differences between group C and the other groups were significant (P < 0.05).     

不同根管充填技术对椭圆形根管充填效果的比较

目的:通过比较3种不同方法充填椭圆形根管后的牙胶充填面积百分数来评价各种充填法的效果。方法:选取人离体单根管前磨牙30个,手用ProTaper预备后随机分为3组,分别用冷牙胶侧方加压法、热塑牙胶注射加压法(ObturaⅢ)和连续波充填法(System B+ObturaⅢ)进行充填,然后分别在距根尖2、5、8 mm处横断,各个横断面在手术显微镜下拍照,再用图像分析软件记录横断面的根管面积和牙胶充填面积,从而计算出牙胶充填面积百分数。结果:在2 mm处,3种充填法的牙胶充填面积百分数无显著性差异(P>0.05);在5 mm处,ObturaⅢ组和SystemB+ObturaⅢ组无显著性差异(P>0.05),但都显著大于冷牙胶侧压组(P<0.05),8 mm与5 mm处结果相同。结论:在5,8 mm水平,ObturaⅢ和SystemB+ObturaⅢ充填法的效果好于冷牙胶侧压法,而在2 mm水平,3种充填法的的效果无明显差别。     

氧化锌充填糊剂与霉菌性上颌窦炎的关系

目的根管过度充填常导致氧化锌丁香油酚充填糊剂进入上颌窦内，本研究的目的是深讨进入窦腔的充填剂同霉菌性上颌窦炎的关系。方法回顾分析33例霉菌性上颌窦炎住院手术患者，男14例，女19例。年龄25～65岁，平均41．3岁，其中12例有患侧上牙行根管治疗史，所有患者行鼻内窥镜手禾治疗，结果术中发现，窦内发现牙原性异物6例，其中牙根1例，充填材料5例，另外发现3例窦腔内有超填的根尖裸露。手术后所有病例随访1～2年无复发。结论含氧化锌充填荆可促使局部霉菌的生长，可能是霉菌性上颌窦炎的一个原因，根管治疗时应避免超填，鼻内窥镜手术是治疗此病的一种新型有效的手段。     

Effect of new obturating materials on vertical root fracture resistance of endodontically treated teeth

The aim of this study was to compare vertical forces at fracture of teeth obturated with different materials. Single-rooted teeth were divided into five groups. The first group served as a negative control. The remaining four groups were shaped using ProTaper rotary files (Dentsply Maillefer, Ballaigues, Switzerland). The second group was obturated with gutta percha and a zinc oxide sealer. The third group was obturated with EndoRez points and EndoRez sealer (both from Ultradent, South Jordan, UT). The fourth group was obturated with Resilon (Pentron Clinical Technologies, Wallingford, CT) and RealSeal sealer (Pentron Clinical Technologies). The fifth group was obturated with Guttaflow (Colténe/Whaledent, Altst?tten, Switzerland). Roots were then fixed into a universal testing machine and loaded with a spreader until fracture. It was found that forces at fracture were statistically significantly higher in the Resilon and EndoRez groups. It was concluded that obturation of roots with resin-based obturation materials (Resilon and EndoRez) increased the resistance of root canal filled teeth to vertical root fracture.     

EZ-FILL双螺旋器法根管充填的微渗漏测定

目的:测定EZ-FILL双螺旋器法和侧方加压根管充填的微渗漏差别.方法:选择50个离体单根管前牙和前磨牙,开髓后预备至0.08锥度,根尖孔预备至#35.样本随机分为4组.A组20例用Ez-FILL双螺旋技术进行根管充填.B组20例用根管侧方加压技术充填.C组5例为阳性对照组,D组5例为阴性对照组.用匍萄糖氧化酶比色测定法测定第1、2、4、7、10、15、20、25、30 d时根尖微渗漏的情况.结果:EZ-FILL根管充填组的微渗漏比侧方加压组稍低,但两组之间的差别无统计学意义(P>0.05).结论:Ez-FILL双螺旋器法充填根管操作简单迅速,同样可以达到侧方加压法相同的根尖封闭效果,有较好的应用前景.     

Apical extrusion of thermoplasticized obturating material in canals instrumented with Profile 0.06 or Profile GT

The purpose of this in vitro study was to compare the extrusion of thermoplacticized gutta-percha in teeth instrumented with Profile 0.06 or Profile GT, and obturated with Thermafil Plus and Thermafil GT, respectively. A total of 120, extracted, human maxillary central incisors were divided into four equal groups. Group 1 was instrumented with Profile 0.06 and obturated with Thermafil Plus. Group 2 was instrumented with Profile 0.06 and obturated using warm vertical condensation (negative control). Group 3 was instrumented with Profile GT and obturated with Thermafil GT. Group 4 was instrumented with Profile GT and obturated like Group 2 (negative control). Extrusion was graded as present or absent. Results found 9 of 30 extruded for group 1, 1 of 30 for group 2, 15 of 30 for group 3, and 2 of 30 for group 4. The results suggest that, in vitro, Thermafil GT may be more prone to extruding gutta-percha past the apical foramen than Thermafil Plus.     

Short-term cytotoxicity assessment of components of the epiphany resin-percha obturating system by indirect and direct contact millipore filter assays

The Epiphany Resin-Percha Obturating System was assessed for cytotoxicity, compared with gutta-percha and AH-Plus sealer. Specimen disks (Resilon, gutta-percha), filled glass rings (sealers), or imbibed cellulose disks (primer, thinning resin) were placed over Millipore filters in direct or indirect contact with HeLa cell monolayer, incubated for 2 hours, and stained with tetrazolium blue. Cytotoxicity was rated by the surrounding unstained zone: none (0 mm), mild (12 mm). Data were analyzed with one-way ANOVA and post hoc pairwise t tests. Unstained zones indicating moderate cytotoxicity were significantly larger (p < 0.05) for Epiphany primer than for thinning resin and for freshly mixed AH-Plus than for Epiphany sealer. Set sealers (24 and 48 hours), gutta-percha, and Resilon elicited noncytotoxic responses. In conclusion, cytotoxicity of set Epiphany sealer and Resilon was comparable with that of set AH-Plus and gutta-percha. Cytotoxicity of freshly mixed Epiphany sealer, primer, and thinning resin did not exceed that of freshly mixed AH-Plus.     

Evaluation of human tooth structure with the ultrasonic imaging technique

In recent years, ultrasonic waves have been an interesting subject for studies due to their wide range of applications in medical diagnoses. In this study, the acoustic properties of the structure of human teeth was determined with the ultrasonic imaging technique. This study may offer some fundamental findings related to the clinical application of the ultrasonic imaging technique in the further development of a virtual system for dental education and research. Twenty freshly-extracted permanent human teeth (10 molars and 10 premolars) were used to investigate their acoustic velocity and impedance by the ultrasonic image analyzing system with a high-resolution focusing probe. Additionally, the relationship between the acoustic properties and the hardness of the teeth was evaluated. It was found that the acoustic properties of the human teeth were influenced by factors related to their structure, such as degree of calcification, distribution of dentinal tubules, and volume of the dentin matrix. The acoustic velocity and impedance showed an apparent correspondence to the hardness of tooth. This analyzing system provides visual information related to tooth structure that can easily quantitatively evaluate their acoustic properties. It is expected that this system will have a wide range of applications and be further developed for clinical uses.     

Evaluation of the Akinosi mandibular block technique in oral surgery

The Akinosi mandibular block technique for administration of local anesthesia was compared with conventional nerve block techniques in patients undergoing the removal of impacted third molars using a within-subject experimental design. Success rates were equivalent, and both techniques resulted in acceptable quality of anesthesia. Buccal nerve anesthesia was achieved with the Akinosi technique in 80% of cases. The Akinosi technique appears to be a successful alternative to traditional mandibular block techniques for oral surgery.     

Effect of different root canal obturating materials on push-out bond strength of a fiber dowel

Purpose: During dowel space preparation, the instrumentation forms a thick smear layer along with sealer‐occluded dentinal tubules. The purpose of this study was to evaluate the effect of different obturating materials on push‐out bond strength of a fiber dowel. Materials and Methods: Fifty human uniradicular teeth were decoronated and prepared using the step‐back technique. The specimens were divided into five groups on the basis of obturating materials: group I received no obturation; group II (ZOE) gutta‐percha and zinc oxide eugenol sealer; group III (ZOAH) gutta‐percha and AH plus sealer; group IV (GF) GuttaFlow; and group V (RE) with Resilon Epiphany system. Dowel spaces were made with manufacturer's provided drills, and a fiber dowel was luted. Horizontal slices were obtained from the middle third, and push‐out bond strength (S) was evaluated. Statistical analysis was carried out using one‐way ANOVA and post hoc Tukey's test. Results: The push‐out bond strength values in the control group, ZOE, ZOAH, GF, and RE were 9.303 ± 0.565 MPa, 8.859 ± 0.539 MPa, 8.356 ± 0.618 MPa, 9.635 ± 0.435 MPa, and 8.572 ± 0.256 MPa, respectively. There was no statistically significant difference between the S values of all the groups (p > 0.05). Conclusion: There was no effect of different tested obturating materials on the push‐out bond strength of fiber dowels; however, further studies should be conducted.     

Evaluation of the castability of a Co-Cr-Mo-W alloy varying the investing technique

The purpose of this study was to compare the castability of Co-Cr-Mo-W (Remanium 2000), Ni-Cr (Durabond) and Co-Cr-Mo (Vera PDI) alloys invested with either conventional (phosphate- and silica-based) or mixed investing techniques. A 10 X 10 mm square-shaped nylon net containing 100 open squares served as a template for construction of wax patterns, which were invested with phosphate-based investment (Termocast), silica-based investment (Refrafil) and mixed investing technique (2-mm layer phosphate investment plus filling with silica investment). Forty-five cast specimens (5 per experimental condition) were obtained and sandblasted with aluminum oxide. The number of completely reproduced cast segments was counted to obtain a percentage designated "castability value", which indicated the accuracy of the alloy to reproduce mold details. Statistical analysis using two-way ANOVA and Tukey's test showed that, comparing the alloys, Remanium 2000 had statistically similar castability (p>0.05) to Vera PDI and lower than Durabond (p<0.05). Considering the mixed technique results, Remanium 2000 yielded lower castability value (p<0.05) than Durabond and Vera PDI alloys, which showed similar results to each other (p>0.05). In conclusion, the castability of the Co-Cr-Mo-W alloy (Remanium 2000) was comparable to that of the Co-Cr alloy (Vera PDI) and worse than that of the Ni-Cr alloy (Durabond). Except for Remanium 2000, the mixed investing technique considerably improved the accuracy of the alloys to reproduce cast details, compared to the phosphate-based investment. The mixed investing technique appears as a viable alternative to improve castability of base metal alloys without decreasing the surface quality of the metallic pieces.