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Braz. dent. j ; 31(6): 605-610, Nov.-Dec. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132347


Abstract This study evaluated the efficiency of using a single instrument from three different rotary multi-file systems and compared them with that of a reciprocating single-file for endodontic retreatment by means of micro-CT. Sixty extracted canines were prepared using a size F2 ProTaper Universal file and obturated. After 30 days of storage at 37ºC and 100% humidity, the teeth were randomly divided into four groups (n=15) based on the type of instrument used to retreatment: ProTaper Next (PTN), ProTaper Gold (PTG), TRUShape 3D (TS), and WaveOne (WO). The canals were retreated using only the size 40 instrument from each system according to the manufacturer's recommendations for torque and speed. The time required to remove the filling material was recorded in seconds. The amount of initial and residual filling material and the quantity of dentin removed were assessed by means of micro-CT. Data were statistically analyzed (ANOVA and Kruskal-Wallis) at a 5% significance level. TS instruments required the highest (p<0.05) amount of time (mean, 384.80 ±144.92) compared with the WO (229.67±68.16) and PTG (248.67±64.22) and not so different from PTN instruments (327.67±133.3). No differences in the amount of dentin removed, initial and residual filling volume, and percentages of filling material were observed among the groups. The use of a single rotary instrument from the PTG, TS, and PTN systems was as effective as that of the single-file reciprocating WO system. However, none of the instruments was able to remove the filling materials completely.

Resumo Este estudo laboratorial avaliou por meio de micro-CT a eficiência do uso de um único instrumento de três sistemas rotatórios em retratamentos endodônticos, comparados a um instrumento único reciprocante. Sessenta caninos extraídos foram preparados usando o sistema ProTaper Universal (F2) e obturados. Após 30 dias de armazenamento a 37 ºC e 100% de umidade, os dentes foram divididos aleatoriamente em quatro grupos (n = 15), de acordo com o instrumento utilizado para remover as obturações endodônticas: ProTaper NEXT (PTN), ProTaper Gold (PTG), TRUShape 3D (TS) e WaveOne (WO). Os canais foram retratados usando apenas o instrumento tamanho 40 de cada sistema, seguindo as recomendações do fabricante para torque e velocidade. O tempo necessário para remover a obturação foi registrado em segundos. A quantidade de material remanescente e o volume de dentina removida foram avaliadas por meio de micro-CT. Análise estatística foi realizada (ANOVA e Kruskal-Wallis), com nível de significância de 5%. O tempo de trabalho no grupo TS foi significativamente maior (p<0.05) (média, 384,80 ± 144,92) comparado a WO (229,67 ± 68,16) e PTG (248,67 ± 64,22), e similar a PTN (327,67 ± 133,3). Não houve diferenças entre os grupos na quantidade de dentina removida e nas porcentagens de material obturador residual. O uso de apenas um instrumento rotatório dos sistemas PTG, TS e PTN foi tão eficaz quanto o do sistema WO reciprocante na remoção do material obturador. No entanto, nenhum dos instrumentos conseguiu remover completamente os materiais obturadores.

Root Canal Filling Materials , Root Canal Obturation , Titanium , Root Canal Preparation , Retreatment , Dental Pulp Cavity , Equipment Design , X-Ray Microtomography , Nickel
Article in Chinese | WPRIM | ID: wpr-751038


Objective @#To compare the shaping ability of 3 different nickel (Ni)-titanium (Ti) systems in simulated root canals in resin and to provide a reference for clinicians.@*Methods@#Forty-eight resin blocks were prepared using the F360 (Komet, Brasseler GmbH & Co., Lemgo, Germany) (Group 1), F6 SkyTaper (20/06) (Komet, Brasseler GmbH & Co., Lemgo, Germany) (Group 2), F6 SkyTaper (25/06) (Komet, Brasseler GmbH & Co., Lemgo, Germany) (Group 3) and Reciproc R25 systems (VDW, Munich, Germany) (Group 4) (n=12 canals/group). The images taken before and after preparation were superimposed and analyzed by Adobe Photoshop v7.0. The amount of resin removed by each system was measured, and the centering ability was assessed. The data were statistically analyzed using SPSS 20.0.@*Results @#At the 1 mm point, the transportation in Group 4 [(0.10 ± 0.03) mm] was significantly greater than that in Groups 2 [(0.05 ± 0.03) mm] and 3 [(0.05 ± 0.03) mm] (P < 0.05). At the 8 mm and 9 mm points, the transportation values in Group 4 [(0.12 ± 0.06) mm and (0.13 ± 0.05) mm] were significantly higher than those in Groups 2 [(0.05 ± 0.05) mm and (0.05 ± 0.05) mm] and 3 [(0.05 ± 0.04) mm and (0.06 ± 0.05) mm] (P < 0.05). At the 10 mm point, the transportation was significantly greater in Group 4 [(0.13 ± 0.06) mm] than in Group 2 [(0.06 ± 0.06) mm].@*Conclusion@#F6 SkyTaper exhibits better centering ability than Reciproc.

Article in Chinese | WPRIM | ID: wpr-750987


Objective @#To compare the removal efficiency and the amounts of apically extruded debris using Twisted File (TF), Twisted File Adaptive (TFA), ProTaper, and ProTaper Next combined with ultrasonic irrigation and to provide an experimental basis for the selection of root canal instrumentation in the clinic.@*Methods@#Forty mandibular premolars were randomly divided into 4 groups (n=10 teeth per group). The canals were cut using a Twisted File, Twisted File Adaptive, ProTaper, or ProTaper Next nickel-titanium instrument. The canals were irrigated with ultrasonic irrigation. The apically extruded debris were collected in preweighted Eppendorf tubes. The amount of dental tissue removed and extruded debris were assessed with an electronic balance.@*Results @#The amount of tooth tissue removed in groups A, B, C and D was 20.5 ± 2.0 mg, 17.8 ± 4.2 mg, 20.8 ± 3.9 mg and 16.5 ± 2.2 mg, respectively. Combined with ultrasonic irrigation, the Twisted File and ProTaper had a better removal efficiency than the ProTaper Next(P < 0.05). There was no significant difference in the amount of extruded debris (χ2=4.057, P=0.255) among four groups.@*Conclusion@#The Twisted File and ProTaper had a better removal efficiency than the ProTaper Next combined with ultrasonic irrigation. There was no significant difference in the amount of extruded debris using four Nickel-titanium instruments combined with ultrasonic irrigation.

Article in Chinese | WPRIM | ID: wpr-777773


Objective@# To compare the differences in the stress distribution in simulated first molars prepared with three rotary nickel-titanium instruments. @*Methods @#Four simulated first molars were prepared without instruments and with Reciproc, WaveOne and Protaper. Before and after preparation, each simulated molar was scanned by Micro-CT. The data were imported to Mimics 16.0 software to establish three-dimensional models. Finite element analysis was processed with Abaqus 6.14 software under conditions of longitudinal and lateral load. @*Results@# Under vertical load conditions, the maximum von Mises stress of the enamel increased by 1.36%, 21.48% and 20.99% in the Reciproc, WaveOne and Protaper groups, respectively, after preparation, while the maximum von Mises stress of the cementum increased by 55.98%, 41.18% and 33.04%, respectively, and the maximum von Mises stress of the alveolar bone increased by 45.55%, 40.37% and 24.09%, respectively. Under 45° lateral load conditions, the maximum von Mises stress of the enamel increased by 1.79%, -4.58% and 3.82% in the Reciproc, WaveOne and Protaper groups, respectively, after preparation, while the maximum von Mises stress of cementum increased by 16.33%, 7.58% and 4.32%, respectively, and the maximum von Mises stress of the alveolar bone increased by 46.82%, 36.40% and 8.29%, respectively. Under the same conditions, the von Mises stresses of the cementum and alveolar bones of the simulated molars were higher after preparation than before preparation, especially under lateral load conditions. The stress was focused on the border between the crown and the root. The von Mises stress of the cementum and alveolar bones increased much more in the Reciproc group than in the other two groups under both conditions.@*Conclusion@#The von Mises stress of simulated molars was greater after preparation than before preparation. The von Mises stress of the cementum and alveolar bones increased much more in the Reciproc group than in the other two groups.

Article in Chinese | WPRIM | ID: wpr-697498


Objective: To study the effect of the modified preparation method with root canal flushing of different solutions on the anti-fracture properties of mechanical nickel-titanium filings. Methods: A transparent resin model of root canal was established. ProTaper Universal (PTU F1) instrument was used to prepare the root canals. The number of prepared root canals by each PTU F1 with the various solutions(n = 20) was recorded and compared among groups. Results: 6. 13 ± 3. 52 root canals were prepared in distilled water group, 6. 25 ± 1. 76 in 0. 9%saline group, 6. 27 ± 2. 07 of 0. 2% chlorhexidine group, 6. 88 ± 3. 21 in 1% sodium hypochlorite group, 4. 31 ± 2. 34 in 5% sodium hypochlorite group and 3. 26 ± 2. 08 in dry drilling group. The number between each 2 of distilled water, 0. 9%saline group, 0. 2%chlorhexidine group and 1% sodium hypochlorite group, and the number between 5% sodium hypochlorite group and dry drilling group was not statistically significant(P> 0. 05). The number of prepared root canals in the first 4 groups was more than that in the latter 2 groups(P< 0. 05). Conclusion: Distilled water, 0. 9% saline, 0. 2% chlorhexidine or 1% sodium hypochlorite for root canal irrigation can improve mechanical nickel-titanium instrument for fatigue resistance in root canal preparation, but 5% sodium hypochlorite and dry drilling can not.

Article in Chinese | WPRIM | ID: wpr-691474


Objective: To compare the shaping ability of ProGlider, HyFlex EDM Glidepath File and RaCe ISO 10 with that of PathFile and stainless steel K-file hand instruments in simulated root canals. Methods: A total of 60 simulated resin blocks were divided randomly into five groups (n=12), each group prepared with each instrument, respectively. Preparation time was recorded. Pre-and post-operative images were obtained using a scanner and superimposed using Photoshop. The material removal from the inner and outer canal walls beginning from 0 mm at the end point of the canal were measured using ImageJ. Centering ability was determined, accordingly. The data were analyzed using the One-Way ANOVA at a significance level of P< 0. 05. Results: Preparation time for ProGlider was (61. 018 ± 5.020) s,significantly the fastest (P< 0.05),that for SS K-file (111. 100 ±6. 987) s, the slowest (P< 0.05),and the differences among the other 3 groups were not significant (P>0. 05). The removal of resin from the outer wall at the apical portion was significantly lower for HyFlex EDM Glidepath File than for ProGlider (P <0. 05),both of them were significantly lower than the other 3 groups (P< 0.05 ). For the removal from the inner wall at the curvature portion,ProGlider was the least whilst SS K-file the most (P< 0.05). At the straight portion,RaCe ISO 10 removed the most not only from the inner but also the outer wall (P <0. 05),HyFlex EDM Glidepath File the second most,and the other 3 groups among the same levels. As far as the centering ability was concerned,at the apical portion,HyFlex EDM Glidepath File was the best,ProGlider the second best,no significant difference identified among the other 3 groups. At the curvature portion,ProGlider and HyFlex EDM Glidepath File were the best,PathFile the second, RaCe ISO 10 the third, the worst was the SS K-file. At the straight portion, the difference amongt the 5 groups was not significant. Conclusion: The shaping abilities of ProGlider, HyFlex EDM Glidepath File and RaCe ISO 10 were better or comparable to that of PathFile,while the preparation time for ProGlider reduced significantly, and HyFlex EDM Glidepath File and RaCe ISO 10 removed significantly more resin at the straight portion of the canal.

Article in English | WPRIM | ID: wpr-714382


OBJECTIVES: The present study aimed to evaluate the shaping ability of 2 thermally treated nickel-titanium reciprocating systems in simulated curved canals. MATERIALS AND METHODS: Forty simulated canals were prepared to apical size 25 using Reciproc Blue R25 (VDW) and WaveOne Gold Primary (Dentsply Sirona) instruments. Standard pre- and post-preparation images were taken and superimposed. The removal of resin material was measured at 5 standard points: the canal orifice, halfway between the canal orifice and the beginning of the curve, the beginning of the curve, the apex of the curve, and the end-point of the simulated canal. The data were analysed using the independent sample t-test with a 5% significance threshold. RESULTS: The canals in which Reciproc Blue R25 was used showed a significantly greater widening than those in which WaveOne Gold was used at 4 of the 5 measurement points (p < 0.05). The Reciproc Blue R25 instrument removed significantly more resin from the inner aspect of the curve at 2 of the 5 points and similar amounts at the remaining 3 points. At the 2 apical points, there was no significant difference between the Reciproc Blue R25 and WaveOne Gold Primary instruments. CONCLUSION: Both instruments respected the original canal anatomy; however, WaveOne Gold resulted in a more conservative shape with less transportation.

Article in Chinese | WPRIM | ID: wpr-666909


Objective To compare the centering ability of three rotary nickel-titanium instruments Reciproc,Protaper and WaveOne in resin-simulated curved root canals.Methods A total of 30 resin-simulated curved canals(curvature=30°)were di-vided into 3 groups(n=10 each)using the random number table.They were prepared with Reciproc(group R),Protaper(group P)and WaveOne(group W)respectively.Pre-and post-operative images were obtained by a digital camera at the fixed position, and superimposed through Photoshop.The center displacement between pre- and post-operative images were measured at 10 points beginning at 1 mm from the end point of the canal with the software Digimizer at a ratio of 1 to 1.The data were analyzed through one-way ANOVA and Student-Newman-Kuels at a significance level ofα=0.05.Results The central point was shifted laterally to the curve at 1,2,and 3 mm from the end point of the canal,while it shifted medially to the curve at 6,7,and 8 mm.The centering ability was better in groups R and W than in group P with significant differences noted(P <0.05).No sig-nificant difference was found in the centering ability between group R and group W.Also there were no significant differences in the centering ability at 4,5,9 and 10 mm among the three groups(P >0.05).Conclusion Reciproc and WaveOne have similar centering ability.They preform better in terms of centering location than Protaper,especially at the apex and the most curved part of the canal.

Article in Chinese | WPRIM | ID: wpr-445192


Objective:To study the factors of nickel titanium instrument(NTI)seperation in posterior tooth root canal therapy.Meth-ods:NTIs were used in 1 498 patients with 1 562 involved posterio teeth and 3 518 root canals for RCT from Jun.2009 to May.2012. The relation of instrument seperation(IS)with gender,age,tooth position,working years of the dentists,bending degree of the in-volved tooth canal and the NTI form was analyzed statistically.Results:68 out off 1 198 applied NTIs(5.68%)were seperated in cal-nal preparation.Single factor analysis showed that IS incidence was not statistically different between male and femal(χ2 =0.013,P >0.05),it was statistically different among the patient ages(χ2 =-354.258,P <0.05),between molar and premolar(χ2 =-201.344,P <0.05),among working years of the dentists(χ2 =13.763,P <0.05),bending degree of involved teeth(χ2 =22.414,P <0.05),times of NTI uses(χ2 =16.807,P <0.05),taper of NTIs(χ2 =18.283,P <0.05)and diameter of NTIs(χ2 =21.312,P <0.05).Logistic analysis showed that age,tooth position,working years of dentists,bending degree of involved tooth canal,frequency of NTIs applica-tion and NTI form were independent risk factors for NTI seperation.Conclusion:Dentists should take appropriate technique and stand-ard operation sequence to reduce the incidence of nickel titanium instrument seperation.

ROBRAC ; 19(49)ago. 2010. graf, ilus
Article in Portuguese | LILACS-Express | LILACS | ID: lil-556310


O objetivo do presente estudo foi analisar a conicidade e regularidade dos canais radiculares preparados com instrumentos rotatórios de níquel-titânio Race® e K3®, utilizando contra ângulo redutor Dentfex®. O experimento envolveu canais me-siais de trinta molares humanos, superiores e inferiores, sendo aleatoriamente distribuídos em dois grupos de quinze, de acordo com os dois tipos de instrumentos rotatórios: RaCe® e K3®. A partir de então, realizou-se a moldagem dos canais radiculares, para em seguida submeter os dentes a desmineralização em ácido clorídrico a 35%, obtendo dessa forma o molde dos mesmos. Esses moldes foram analisados, onde se verifcou a conicidade e regularidade dos canais radiculares preparados. Os dados foram tabulados e submetidos à análise estatística por meio dos testes de Mann-Whitney e Qui-quadrado. Os resultados obtidos indicam a predominância de formas regulares cônicas, em todos os terços (cervical, médio, apical), nos sentidos mésio vestibular e mésio lingual e palatino dos canais preparados com os instrumentos Race® e K3®, mas houve diferença estatisticamente signifcante entre o número de ocorrência da forma irregular cilíndrica nos moldes dos canais mésio-vestibulares inferiores, preparados com os instrumentos RaCe®.

The aim of this study was to analyze the taper and regularity of root canals prepared with rotary nickel-titanium system Race® and K3®, using angle reducer Dentfex®. The experiment involved mesial canals of thirty human molars, upper and lo-wer were randomly assigned to two groups of ffteen, according to the two types of rotary instruments: RaCe® and K3®. Since then, there was casting of root canals, to then subject the teeth to demineralization in 35% hydrochloric acid, thereby obtaining the same mold. These paterns were analyzed, where there was a taper and regularity of root canals prepared. The data were tabulated and analyzed statistically by the Mann-Whitney and Chi-square. The results indicate the predominance of regular conical forms, in all thirds (cervical, middle, apical) in mesial buccal and mesial lingual and palatine canals prepared with Race® and K3®, but statistically signifcant diference between the number of occurrence of irregular cylindrical shape along the lines of mesiobuccal canals below, prepared with RaCe®.

Article in Chinese | WPRIM | ID: wpr-670963


Objective:To evaluate the shaping effects of multi-taper ProTaper combined with nickel-titanium(Ni-Ti) K file in simulated S-shaped canals. Methods:Thirty simulated S-shaped resinous canals were randomly divided into three groups and prepared with hand ProTaper, hand Ni-Ti K file, hand ProTaper combined with Ni-Ti K file respectively. The shaping effects were assessed by the amount of material removed from the inner and outer wall of canal as well as the width of canal after instrumentation. Results: The shaping files of ProTaper removed the least material in amount of materials from the same apical dimension. The finishing files of ProTaper removed the most amount of material at the inner side of curvature and outer side of apex. ProTaper combined with Ni-Ti K file removed the least material at the above parts and the widths of canals prepared were gradually decreased from the orifice to the apex. Conclusion:ProTaper combined with Ni-Ti K file exhibited good shaping effects in simulated S-shaped canals.

Article in Chinese | WPRIM | ID: wpr-544754


Objective: To evaluate shaping ability of nickel-titanium rotary instruments (Hero 642) in curved root canals. Methods:The computer assistant measure system of simulated root canal was used for quantitative analysis of root shape in eight simulated root canals during nickel-titanium rotary instruments (Hero 642) shaping process. Results:Nickel-titanium rotary instruments (Hero 642) could keep the curved angles in simulated canals very well. The cutting of Hero 642 in curved root canals was balanced and there was almost no transportation of canals central lines when the simulated canals were prepared to 0.02 taper 25~# and 30~# files. Conclusion:Nickel-titanium rotary instruments (Hero 642) has good shaping ability. In preparation of highly curved canals, the master apical file (MAF) may be Hero 642 0.02 taper 30# files.