Apical extrusion of debris with root canal instrumentation in primary teeth A systematic review

Aim: This study aimed to systematically review available literature of in vitro studies on apical extrusion of debris through rotary instrumentation in comparison to manual instrumentation in pediatric endodontics, and also to perform a comparison between various rotary instrumentation systems for assessment of debris extrusion. Materials and Methods: A comprehensive search was conducted on PubMed, Medline, Cochrane Library, Embase, Scopus, and Google Scholar without any language restriction and year of publication. A planned search strategy was made for PubMed and applied to other databases. After full-text reading, 7 articles were selected for quantitative synthesis. Modified CONSORT checklist of items for reporting in vitro studies of dental materials was used for quality assessment of included studies. Results: Root canal preparation with rotary instrumentation led to lesser apical debris extrusion than manual instrumentation. Self-adjusting file system was associated with the least debris extrusion among all included studies, followed by ProTaper Next, Kedo-S, ProTaper, K3, Mtwo, Revo-S, and Wave One. Conclusion: More apical debris extrusion was seen with manual instrumentation than rotary instrumentation. Furtrhermore, variance in debris extrusion was seen with different rotary file systems.

Assessment of the Performance and Surface Alteration of Two Single-file Systems According to the Number of Uses

Abstract The aim of this study was to assess the performance and surface alteration of two single-file systems according to the number of uses. Ten WaveOne Primary files (25/.08) and ten One Shape NG files (25/.06) were used for instrumentation of mesial root canals of mandibular molars. Each instrument was cleaned and sterilized after the preparation of two root canals and then reused. The time spent for instrumentation of each root canal was recorded and analyzed by using t-test. Microphotographs of the surface of the instruments were taken with a scanning electron microscope at different magnifications (i.e. 18x, 160x, 500x and 1000x) and at a distance of 4 mm from the instrument's tip before being analyzed by four observers. Presence of disruption of cutting edge, crack, craters and unwinding was assessed and submitted to Fisher's exact test. Both systems showed manufacturing defects and cracks. The presence of disruption of cutting edges was major in WaveOne files from the sixth use, whereas One Shape NG files showed more unwinding. Only preparation time using WaveOne files was influenced by the number of uses. One can conclude that WaveOne files had more disruption of cutting edges and took longer time for root canal preparation from the sixth use onwards, whereas the One Shape NG files showed more unwinding at the tenth use.

Evaluation of the waveone gold and one shape new generation in reducing enterococcus faecalis from root canal

Abstract The aim of this study was to evaluate the WaveOne Gold and One Shape New Generation systems regarding the bacterial removal from root canals infected with Enterococcus faecalis by comparing them to the conventional WaveOne and One Shape systems. Forty-eight distobuccal root canals of maxillary molars sterilized with ethylene oxide were infected with E. faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 4 groups according to the instrumentation: WaveOne Gold, One Shape New Generation, WaveOne and One Shape. After instrumentation, samples were collected with use of scraping and paper cones at immediate and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by Friedman test and intergroup analysis by Kruskal-Wallis with Dunn's post-hoc test, all at 5% significance. All techniques significantly reduced the number of bacteria in the root canal (p<0.05). WaveOne Gold and One Shape New Generation promoted higher bacterial reduction than WaveOne and One Shape systems (p<0.05), but no significant difference was found between WaveOne Gold and One Shape New Generation or between WaveOne and One Shape (p>0.05). Novel single-file systems promote better bacterial removal than the conventional single-file systems.

Resumo A proposta deste estudo foi avaliar os sistemas WaveOne Gold e One Shape New Generation em relação à remoção bacteriana de canais infectados com Enterococcus faecalis, comparando-os com seus sistemas convencionais WaveOne e One Shape. Quarenta e oito canais disto vestibulares de molares superiores esterilizados em óxido de etileno foram contaminados com E. faecalis por 21 dias, e então acoleta bacteriana inicial foi feita com cone de papel e plaqueadas em M-enterococcus agar. Os espécimes foram aleatoriamente divididos em quarto grupos de acordo com a instrumentação: WaveOne Gold, One Shape New Generation, WaveOne e One Shape. Após instrumentação, amostras foram coletadas utilizando limagem e cones de papel imediatamente e 7 dias após o preparo. A redução bacteriana foi calculada e então feita análise intra grupos com teste de Friedman, e entre grupos utilizando Kruskal-Wallis e teste de Dunn, todos a 5% de significância. Todas as técnicas reduziram significantemente o número de bactérias do canal radicular (p<0.05). WaveOne Gold e One Shape New Generation promoveram maior redução bacteriana que WaveOne e One Shape (p<0.05), mas nenhuma diferença significante foi encontrada entre WaveOne Gold e One Shape New Generation ou entre WaveOne e One Shape (p>0.05). Novos sistemas de lima-única promovem melhor remoção bacteriana que seus sistemas convencionais.

Instrument Design May Influence Bacterial Reduction During Root Canal Preparation

Abstract The aim of this study was to evaluate the bacterial reduction promoted by ProTaper Next and Twisted File by comparing to ProTaper Universal and manual technique. Sixty distobuccal root canals of maxillary molars sterilized with ethylene oxide were contaminated with Enterococcus faecalis broth culture. After incubation for 21 days, bacterial samples were collected and cultured on m-Enterococcus agar plates. The root canals were divided into 4 groups, according to the system used for instrumentation: ProTaper Next, Twisted File, ProTaper Universal, and crown down manual technique. Other 8 uncontaminated root canals were control asepsis. Bacterial samples were collected immediately and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by paired t-test and intergroup analysis by ANOVA and Tukey tests, all at 5% significance. All techniques significantly reduced the bacterial number in the root canal (p<0.05). ProTaper Next and Twisted File resulted in more bacterial reduction than ProTaper Universal and manual technique (p<0.05). ProTaper Next and Twisted File were similar (p>0.05). It can be concluded that ProTaper Next and Twisted File promote a higher bacterial reduction than Protaper Universal and manual technique.

Resumo A proposta deste estudo foi avaliar a redução bacteriana promovida pelos sistemas ProTaper Next e Twisted File comparando-os ao sistema ProTaper Universal e técnica manual. Sessenta raízes disto vestibulares de molares superiores esterilizadas com óxido de etileno foram contaminadas com Enterococcus faecalis. Após incubação por 21 dias, amostras foram coletas e cultivadas em m-Enterococcus agar. Os canais foram divididos em 4 grupos de acordo com o sistema de instrumentação: ProTaper Next, Twisted File, ProTaper Universal, e técnica manual crown-down. Outros 8 canais não contaminados foram utilizados como controle de assepsia. Amostra bacteriana foi coletada imediatamente após o prepare e aos 7 dias. A redução bacteriana foi calculada, e então feita a análise intergrupos utilizando teste t-pareado, e análise entre grupos utilizando os testes ANOVA e Tukey, todos com 5% de significância. Todas as técnicas reduziram significantemente o número de bactérias no canal radicular (p<0.05). ProTaper Next e Twisted File resultaram em maior redução bacteriana que ProTaper Universal e técnica manual (p<0.05). ProTaper Next e Twisted File foram semelhantes (p>0.05). Pode-se concluir que ProTaper Next e Twisted File promovem maior redução bacteriana que Protaper Universal e técnica manual.

Comparison of canal transportation in simulated curved canals prepared with ProTaper Universal and ProTaper Gold systems

OBJECTIVES: The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. MATERIALS AND METHODS: Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at alpha = 5%. RESULTS: Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). CONCLUSIONS: PTG system produced overall less canal transportation in the curved portion when compared to PTU system.

Comparison of canal transportation in simulated curved canals prepared with ProTaper Universal and ProTaper Gold systems

OBJECTIVES: The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. MATERIALS AND METHODS: Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at alpha = 5%. RESULTS: Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). CONCLUSIONS: PTG system produced overall less canal transportation in the curved portion when compared to PTU system.

Relationship between files that bind at the apical foramen and foramen openings in maxillary central incisors - a SEM study

Considering that instrumentation of the apical foramen has been suggested for root canal infection control, this study analyzed the relationship between the files that bind at the apical foramen and the foraminal openings in 50 maxillary central incisors. After preparation of the pulp chamber, access to the canal was obtained with #1 and 2 LA Axxess and K-files with tip cut were inserted up to the apical foramen until binding was felt. The files were fixed with methyl cyanoacrylate and the tooth-file sets were cross-sectioned 10 mm short of the apex. Scanning electron microscopic analysis was carried out and files and foraminal areas were measured using Image Tool software. Statistically significant difference (p<0.0001) was found between files and the apical foraminal areas. The mean foraminal area was 3.8 times larger than the mean file area. The results of this study suggest that it would require 4 files of greater size beyond the one that bound to the foramen in order to allow a better relationship between files and apical openings of maxillary central incisors.

Uma vez que a instrumentação do forame apical tem sido sugerida para o controle de infecção do canal radicular, este estudo analisou a relação entre as limas que se ajustam no forame apical e a abertura foraminal em cinquenta incisivos centrais superiores. Após o preparo da câmara pulpar, foi feito o acesso radicular com as brocas LA Axxess #1 e 2 e limas K com a ponta cortada foram inseridas até que oferecessem a sensação tátil de ajuste no forame apical. Foram fixadas com cianoacrilato de metila e o conjunto dente-lima foi seccionado a 10 mm aquém do ápice. Foi feita a microscopia eletrônica de varredura e as áreas das limas e dos forames foram medidas por meio do Image Tool software. A análise estatística demonstrou diferença significante entre as áreas das limas e dos forames (p<0,0001). A média da área dos forames apicais foi 3,8 vezes maior que a das limas. Os resultados deste estudo sugerem que seriam necessários 4 instrumentos de calibre maior além do que se ajustou para que haja melhor relação entre as limas e as aberturas foraminais nos incisivos centrais superiores.

CT evaluation of apical canal transportation associated with stainless steel hand files, oscillatory technique and ProTaper rotary system

This study used computed tomography (CT) to compare apical canal transportation in mesiobuccal canals of maxillary molars prepared with different techniques. Sixty teeth were assigned to 3 groups (n=20), according to the technique used for root canal instrumentation: hand instrumentation with K-Flexofiles, K-Flexofiles activated by an oscillatory system and ProTaper NiTi rotary system. Pre and post-instrumentation CT images were obtained 3 mm short of the apical foramen and were superimposed to compare canal transportation. Data were analyzed statistically by ANOVA and Tukey's test using the SPSS software (α=0.05). In the buccal direction, the manual technique produced significantly less canal transportation than the oscillatory technique (p<0.05) and both were similar to the rotary technique (p>0.05). In the distal and distopalatal directions, the oscillatory technique produced more canal transportation (p<0.05). In the mesiopalatal direction, the oscillatory technique produced more canal transportation than the manual technique (p<0.05), and both were similar to the rotary technique (p>0.05). In conclusion, all techniques produced canal transportation, and the oscillatory technique produced the greatest removal of root dentin toward the innerside of the root curvature.

Este estudo utilizou a tomografia computadorizada (TC) para comparar o transporte do canal radicular nos canais mésio-vestibulares de molares superiores preparados por diferentes técnicas. Sessenta molares superiores foram divididos em 3 grupos (n=20) de acordo com a técnica utilizada para o preparo do canal radicular: instrumentação manual com limas K-Flexofile, limas K-Flexofile acopladas a um sistema oscilatório e sistema rotatório ProTaper. Imagens de TC pré e pós-instrumentação foram obtidas 3 mm aquém do forame apical e superpostas para comparar o transporte do canal. Os dados foram analisados estatisticamente pela Análise de Variância (ANOVA) e Teste de Tukey utilizando o software SPSS (α=0,05). Na direção vestibular, a técnica manual produziu significantemente menos transporte do canal radicular do que a técnica oscilatória (p<0,05) e ambas foram similares a técnica rotatória (p>0,05). Nas direções distal e disto-palatina, a técnica oscilatória produziu mais transporte do canal radicular (p<0,05). Na direção mésio-palatina, a técnica oscilatória produziu mais transporte do canal radicular do que a técnica manual (p<0,05), sendo que ambas foram similares à técnica rotatória (p>0,05). Em conclusão, todas as técnicas produziram transporte do canal radicular e a técnica oscilatória produziu os maiores desgastes de dentina na direção interna da curvatura.

Canal transportation in simulated root canals instrumented with one progressive taper and two constant taper nickel-titanium rotary systems

This study investigated the occurrence of canal transportation in the apical third of simulated root canals instrumented with progressive and constant taper shaft designed rotary instruments. Thirty simulated resin canals were prepared with progressive taper (ProTaper Universal) and constant taper (Hero 642 and K3) Ni-Ti rotary systems, with 10 canals per group. The pre and post-instrumentation images of the canals were superimposed and the composite images were analyzed with Image Pro Plus 5.0 software. Centering ability of the instruments was assessed by subtracting the amount of resin removed at the inner wall from that removed at the outer wall. Total amount (in mm) of resin removed was recorded by adding the amount of resin removed at the inner and outer walls, comparing the pre and post-preparation images. Data were analyzed statistically by Kruskal Wallis and Median tests (α=5%). There was statistically significant difference (p<0.05) among the groups. ProTaper produced the greatest canal transportation in the apical third. In conclusion, canal transportation occurred in all groups; the constant taper rotary instruments (Hero 642 and K3) presented greater centering ability towards the original canal curve and caused less canal transportation than the progressive taper instruments (ProTaper).

Este estudo investigou a ocorrência do transporte do canal no terço apical de canais simulados preparados com instrumentos rotatórios de conicidade progressiva e constante. Trinta canais simulados em blocos de resina foram preparados com sistemas rotatórios de Ni-Ti de conicidade progressiva (ProTaper Universal) e de conicidade constante (Hero 642 e K3), com 10 canais simulados por grupo. As imagens pré e pós-operatórias dos canais foram superpostas e analisadas com o Programa Image Pro Plus 5.0. A capacidade de manter a centralização do canal foi avaliada pela subtração da quantidade de resina removida da parede interna daquela removida na parede externa. A quantidade total de resina (em mm) removida foi obtida por meio da soma da resina removida das paredes internas e externas do canal, comparando as imagens pré e pós-operatórias. Os dados foram analisados estatisticamente pelo teste de Kruskal Wallis e Teste das medianas (α=5%). Houve diferença estatisticamente significativa (p<0.05) entre os grupos. O Sistema ProTaper produziu o maior transporte do canal no terço apical. Em conclusão, o transporte do canal ocorreu em todos os grupos; os intrumentos rotatórios de conicidade constante (Hero 642 e k3) apresentaram uma grande capacidade de manter o canal centrado e causaram menos transporte do canal do que os instrumentos de conicidade progressiva (ProTaper).

In vitro comparative study of manual and mechanical rotary instrumentation of root canals using computed tomography

This in vitro study compared, using computed tomography (CT), the amount of dentin removed from root canal walls by manual and mechanical rotary instrumentation techniques. Forty mandibular incisors with dental crown and a single canal were selected. The teeth were randomly assigned to two groups, according to the technique used for root canal preparation: Group I - manual instrumentation with stainless steel files; Group II - mechanical instrumentation with RaCe rotary nickel-titanium instruments. In each tooth, root dentin thickness of the buccal, lingual, mesial and distal surfaces in the apical, middle and cervical thirds of the canal was measured (in mm) using a multislice CT scanner (Siemens Emotion, Duo). Data were stored in the SPSS v. 11.5 and SigmaPlot 2001 v. 7.101 softwares. After crown opening, working length was determined, root canals were instrumented and new CT scans were taken for assessment of root dentin thickness. Pre- and post-instrumentation data were compared and analyzed statistically by ANOVA and Tukey's post-hoc test for significant differences (p=0.05). Based on the findings of this study, it may be concluded that regarding dentin removal from root canal walls during instrumentation, neither of the techniques can be considered more effective than the other.

Este estudo in vitro avaliou comparativamente, por meio de tomografia computadorizada (TC), a quantidade de dentina removida das paredes do canal radicular utilizando-se as técnicas de preparo manual e automatizada de instrumentação rotatória. Foram selecionados 40 incisivos inferiores com coroa dental e um único canal. Os dentes foram divididos aleatoriamente em 2 grupos, de acordo com a técnica empregada para o preparo dos canais radiculares: Grupo I - técnica manual com limas manuais de aço inoxidável e Grupo II - técnica automatizada de movimentos rotatórios RaCe com limas de níquel-titânio. Em cada dente, procedeu-se à mensuração (em mm) da espessura da dentina radicular nas faces vestibular, lingual, mesial e distal dos terços apical, médio e cervical por meio de tomografia computadorizada multislice (Siemens Emotion, Duo). Os dados coletados foram armazenados utilizando-se os softwares SPSS versão 11.5 e SigmaPlot 2001 v. 7.101 (SPSS Inc.). Após a abertura coronária, o comprimento de trabalho foi estabelecido, os canais radiculares foram instrumentados e novas tomadas de tomografia computadorizada foram realizadas para mensuração da espessura das paredes dentinárias radiculares. Os dados obtidos antes e após o preparo biomecânico dos canais foram comparados. Os resultados foram estatisticamente por meio de análise de variância (ANOVA) com localização de diferenças post hoc de Tukey (p=0,05). Com base nos achados desse estudo, pode-se concluir que: com relação à remoção de dentina das paredes dos canais radiculares durante a instrumentação nenhuma das técnicas avaliadas pode ser apontada como mais efetiva que a outra.