Antibacterial ability of different activated irrigation after root canal preparation: intratubular analyses.

This study assessed the intratubular antibacterial ability of different activated irrigations after chemical mechanical preparation. Seventy-two palatal root canals of upper molars were infected with Enterococcus faecalis for 4 weeks, and then initial bacterial collection from the main root canal was performed. The root canals were prepared by using a WaveOne Gold large (45/.05) and distributed into 6 groups according to the activation of the final irrigation: ultrasonic activation (UA), XP-Endo Finisher (25/.00), XP Clean (25/.02), EasyClean (25/.04) in reciprocating motion and continuous rotary motion (ECRot), and conventional irrigation. After final irrigation, another bacterial collection from the main root canal was performed, and the root was sectioned transversely in three-thirds and stained for analysis by confocal laser microscopy. Intratubular bacteria were collected through dentin powder and plated for bacterial viability analysis. Intergroup and intragroup comparisons were performed by using analysis of variance and repeated measures analysis of variance, respectively, both at 5% significance. ECRot had higher antibacterial ability than UA (p<0.05), and both were superior to the other groups (p<0.05) in both methodologies. It can be concluded that activation of final irrigation enhances the disinfection of the root canal system, and activators have different efficacies.

Tooth bleaching induces changes in the vascular permeability of rat incisor pulps.

PURPOSE: To evaluate the inflammatory response in dental pulps of rat incisors subjected to tooth bleaching protocols with different HP concentrations and application times. METHODS: 42 incisors from Wistar rats were submitted to tooth bleaching using concentrations of 25% or 35% HP for treatment times of 15, 30 or 45 minutes. Four non-bleached teeth were used as controls. The animals received an intravenous injection of India ink immediately after the bleaching procedure and were sacrificed 1 hour later. Six bleached teeth from each group and three controls were made transparent, and one sample from each group was processed for histological analysis. The data were statistically analyzed using Kruskal Wallis and Dunn's tests (P < 0.05). RESULTS: The amount of dental pulp ink content was significantly higher in the samples that were bleached with 35% HP for 30 minutes and with both HP concentrations (25 and 35%) for 45 minutes than in the controls. For the samples bleached with the same HP concentration, the ink content was higher in samples that were bleached for 45 minutes. These results indicate that HP tooth bleaching can induce an increase in vascular permeability in rat incisors. Importantly, this increase is more dependent on the length of the bleaching procedure than on the concentration of the bleaching agent.

Optimization of automated preparation of long oval-shaped root canals using supplementary instrumentation.

This study compared the preparation of long oval-shaped root canals using WaveOne Gold and XP-endo Shaper systems, both supplemented or not with manual instrumentation. Twenty-four long oval-shaped canals of mandibular incisors were distributed into two groups according to the instrumentation: WaveOne Gold Primary or XP-endo Shaper systems. All root canals were manually instrumented with a size 25 K-file after automated preparation. The specimens were scanned by using a micro-CT device (17.42 µm) before and after automated preparation and manual instrumentation. The increased surface of the root canal and the percentage of untouched areas were assessed. Both WaveOne Gold and XP-endo Shaper systems increased the root canal surface and had similar untouched areas (p>0.05). Supplementary instrumentation increased the surface of the root canal and decreased the untouched walls (p<0.05). WaveOne Gold and XP-endo Shaper systems provided a similar preparation of long oval-shaped canals and manual instrumentation improved their preparation.

Effect of human dental pulp stem cell conditioned medium in the dentin-pulp complex regeneration: A pilot in vivo study.

BACKGROUND: Dental trauma, restorative operative procedures and/or caries lesions can expose the dental pulp. Facing this clinical condition, where the maintenance of the dentin-pulp complex vitality is imperative, is challenging in Dentistry. Dental pulp stem cells conditioned medium contains trophic factors that could help in this task. This in vivo pilot study aimed to evaluate the effects of the human dental pulp stem cells conditioned medium on the dental pulp tissue response to vital pulp therapy. MATERIAL AND METHODS: Concentrated conditioned medium was obtained by incubating characterized human dental pulp stem cells with fresh culture medium. Pulp exposures performed at the first upper molars (n = 20) of Wistar rats were directly capped with: MTA or MTA + Conditioned Medium. Four and 8 weeks later, the samples were qualitatively analyzed in histological sections (H&E). RESULTS: When the conditioned medium was associated with MTA, there were a high percentage of samples presenting formation of dentin bridges and small percentage of pulp tissue with inflammatory signs in both experimental times. The conditioned medium improved the organization of the newly formed hard tissue. CONCLUSIONS: The association of dental pulp stem cell conditioned medium with MTA showed beneficial effects on dentin-pulp complex regeneration and has promising potential for studies in regenerative dentistry.

Confocal laser scanning microscopic analysis of the penetration of an epoxy resin-based sealer into dentinal tubules after calcium hydroxide dressing.

This study assessed the penetration of an epoxy resin-based sealer into dentinal tubules of root canals previously medicated with calcium hydroxide. Sixteen palatal root canals of upper molars were instrumented and distributed into two groups: (G1) root canals medicated with calcium hydroxide and obturated after its removal; (G2) root canals obturated without the use of dressing. Sealer mixed with rhodamine B provided fluorescence for confocal laser scanning microscopy. Measurements of area and linear penetration of the sealer were assessed in three thirds by ImageJ software. The data were statistically compared by Kruskal-Wallis, Dunn's and Mann-Whitney U tests (P < 0.01). The calcium hydroxide decreased the penetration of the sealer. The coronal and middle thirds had similar areas and linear penetrations in both groups, whereas the apical third had less penetration. In conclusion, the penetration of the epoxy resin-based sealer is influenced by the calcium hydroxide dressing used between appointments.

Development and characterization of a new chitosan-based scaffold associated with gelatin, microparticulate dentin and genipin for endodontic regeneration.

OBJECTIVE: An ideal scaffold for endodontic regeneration should allow the predictableness of the new tissue organization and limit the negative impact of residual bacteria. Therefore, composition and functionalization of the scaffold play an important role in tissue bioengineering. The objective of this study was to assess the morphological, physicochemical, biological and antimicrobial properties of a new solid chitosan-based scaffold associated with gelatin, microparticulate dentin and genipin. METHODS: Scaffolds based on chitosan (Ch); chitosan associated with gelatin and genipin (ChGG); and chitosan associated with gelatin, microparticulate dentin and genipin (ChGDG) were prepared by using the freeze-drying method. The morphology of the scaffolds was analyzed by scanning electron microscopy (SEM). The physicochemical properties were assessed for biodegradation, swelling and total released proteins. The biological aspects of the scaffolds were assessed using human cells from the apical papilla (hCAPs). Cell morphology and adhesion to the scaffolds were evaluated by SEM, cytotoxicity and cell proliferation by MTT reduction-assay. Cell differentiation in scaffolds was assessed by using alizarin red assay. The antimicrobial effect of the scaffolds was evaluated by using the bacterial culture method, and bacterial adhesion to the scaffolds was observed by SEM. RESULTS: All the scaffolds presented porous structures. The ChCDG had more protein release, adhesion, proliferation and differentiation of hCAPs, and bacteriostatic effect on Enterococcus faecalis than Ch and ChGG (p < 0.05). SIGNIFICANCE: The chitosan associated with gelatin, microparticulate dentin and genipin has morphological, physicochemical, biological and antibacterial characteristics suitable for their potential use as scaffold in regenerative endodontics.

Antibacterial ability of different activated irrigation after root canal preparation: intratubular analyses

Abstract This study assessed the intratubular antibacterial ability of different activated irrigations after chemical mechanical preparation. Seventy-two palatal root canals of upper molars were infected with Enterococcus faecalis for 4 weeks, and then initial bacterial collection from the main root canal was performed. The root canals were prepared by using a WaveOne Gold large (45/.05) and distributed into 6 groups according to the activation of the final irrigation: ultrasonic activation (UA), XP-Endo Finisher (25/.00), XP Clean (25/.02), EasyClean (25/.04) in reciprocating motion and continuous rotary motion (ECRot), and conventional irrigation. After final irrigation, another bacterial collection from the main root canal was performed, and the root was sectioned transversely in three-thirds and stained for analysis by confocal laser microscopy. Intratubular bacteria were collected through dentin powder and plated for bacterial viability analysis. Intergroup and intragroup comparisons were performed by using analysis of variance and repeated measures analysis of variance, respectively, both at 5% significance. ECRot had higher antibacterial ability than UA (p<0.05), and both were superior to the other groups (p<0.05) in both methodologies. It can be concluded that activation of final irrigation enhances the disinfection of the root canal system, and activators have different efficacies

Resumo Este estudo avaliou a capacidade antibacteriana intratubular de diferentes irrigações ativadas após o preparo químico-mecânico. Setenta e dois canais palatinos de molares superiores foram contaminados com Enterococcus faecalis por 4 semanas, e então a coleta bacteriana inicial do canal principal foi realizada. Os canais foram preparados com WaveOne Gold large (45/.05) e distribuídos em 6 grupos de acordo com a ativação da irrigação final: ativação ultrassônica (UA), XP-Endo Finisher (25/.00), XP Clean (25/.02), EasyClean (25/.04) em movimento reciprocante e em movimento rotatório contínuo (ECRot) e irrigação convencional. Após a irrigação final, outra coleta bacteriana do canal principal foi realizada, e a raiz foi seccionada transversalmente em três terços e corada para análise por microscopia laser confocal. Bactérias intra tubulares foram coletadas através de pó de dentina e cultivadas para análise de viabilidade bacteriana. As comparações entre grupos e intragrupos foram realizadas usando análise de variância e análise de variância de medidas repetidas, respectivamente, ambas com 5% de significância. ECRot apresentou maior capacidade antibacteriana que UA (p<0,05), e ambos foram superiores aos demais grupos (p<0,05) em ambas as metodologias. Pode-se concluir que a ativação da irrigação final melhora a desinfecção do sistema de canais radiculares, e os ativadores têm eficácias diferentes.

Estado actual de la infección focal y del éxito del tratamiento endodóntico / Current status of focal infection and the success of endodontic treatment

Frente a la difusión en medios de comunicación de medias verdades con enunciados alarmantes y anticientíficos, este editorial busca revisar las bases científicas para determinar el comportamiento clínico. Así, el texto discurre por el concepto de infección focal desde su origen, yendo al encuentro de sus transformaciones conceptuales a través de los descubrimien- tos científicos, teniendo en cuenta las características emocio- nales propias de cada paciente como un todo y los peligros a los que se puede estar expuestos frente a las medias verdades (AU)

Facing the diffusion of alarming and anti-scientific state- ments in the media, this editorial seeks the scientific bases to determine the clinical behavior. Thus, the text runs through the concept of focal infection from its origin and across its conceptual transformations through scientific discoveries, by considering the emotional characteristics of each patient as a whole and the dangers to which they may be exposed in the face of half-truths (AU)

Estado actual de la infección focal y del éxito del tratamiento endodóntico / Current status of focal infection and the success of endodontic treatment

Resumen Frente a la difusión en medios de comunicación de medias verdades con enunciados alarmantes y anticientíficos, este editorial busca revisar las bases científicas para determinar el comportamiento clínico. Así, el texto discurre por el concepto de infección focal desde su origen, yendo al encuentro de sus transformaciones conceptuales a través de los descubrimientos científicos, teniendo en cuenta las características emocionales propias de cada paciente como un todo y los peligros a los que se puede estar expuestos frente a las medias verdades.

Abstract Facing the diffusion of alarming and anti-scientific statements in the media, this editorial seeks the scientific bases to determine the clinical behavior. Thus, the text runs through the concept of focal infection from its origin and across its conceptual transformations through scientific discoveries, by considering the emotional characteristics of each patient as a whole and the dangers to which they may be exposed in the face of half-truths.

Invasive Cervical Resorption: Clinical Management in the Anterior Zone.

According to the high number of articles published on invasive cervical resorption (ICR), this pathology, as commonly believed, is a more frequent form of cervical resorption. ICR is often misdiagnosed as internal resorption or caries, which leads to inappropriate treatment and even unnecessary tooth loss. Despite a correct diagnosis, the treatment of this type of hyperplastic invasive external resorption poses a challenge for the clinician. The Heithersay classification and the use of cone-beam computed tomographic imaging have increased our knowledge of the pathology and helped improve its prognosis. Nevertheless, there is no standard protocol for the treatment of this type of lesion. This article proposes a treatment protocol for ICR based on the pattern and location of resorption. Three treatment approaches (internal access, external access, and intentional replantation) are presented through 3 clinical cases.

Immunohistological study of the effect of vascular Endothelial Growth Factor on the angiogenesis of mature root canals in rat molars.

Tissue bioengineering has been applied to Endodontics to seek a more biological treatment. The presence of blood vessels is crucial for cell nutrition during tissue formation. Objective This study analysed the application of vascular endothelial growth factor (VEGF) in the angiogenesis of mature root canals. Material and methods Upper first molars of twelve 13-week old Wistar male rats were used. The root pulp of the mesiobuccal canal was removed and the root canal instrumented with K-files up to size #25. Periapical bleeding was induced into the root canal by introducing a #15 K-file beyond the apex. The teeth on the right side of the arch were filled up with blood clot (G1), whereas those on the left side were filled up with blood clot plus 50 ng/ml of VEGF (G2). Teeth were sealed with light-curing glass-ionomer cement and the animals were sacrificed after 60 days. The maxilla was dissected and fixed before obtaining serial sections for histological processing with haematoxylin-eosin (HE) and immunohistochemical factor-VIII. Immunohistochemical labelling was evaluated using scores for statistical analysis. Results Immunohistological analysis demonstrated the presence of angiogenesis in both groups, but with higher angiogenic maturation in G2 during the experimental period (p<0.05). HE staining showed connective tissue with absence of odontoblasts in all specimens. Conclusions It can be concluded that it is possible to obtain angiogenesis in mature root canals with or without the use of VEGF, although the latter tends to accelerate blood vessel formation.

Nickel-titanium instruments in endodontics: a concise review of the state of the art.

The introduction of automated instrumentation in endodontics represented a major advance in progress for this specialty, with improvements in the quality and predictability of root canal preparation and a significant reduction in procedural errors. In recent years, endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments. In addition, new movements have also been incorporated to offer greater safety and efficiency, optimizing the properties of the NiTi alloy, especially through eccentric rotary motion. An understanding of the mechanical properties of these new NiTi instruments and their effect on the clinical performance of root canal preparation is essential if dental practitioners are to select the instruments that provide optimal clinical outcomes, especially in curved or flattened canals. The objective of this literature review is to present and discuss the characteristics of the NiTi alloys used in the major instrumentation systems available in the market, as well as the influence of the metallurgical and mechanical properties of NiTi instruments and the movements that drive them, to enable more accurate and predictable planning of root canal preparation.

Evaluation of the WaveOne Gold and One Shape New Generation in Reducing Enterococcus faecalis from Root Canal.

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.

Optimization of automated preparation of long oval-shaped root canals using supplementary instrumentation

Abstract This study compared the preparation of long oval-shaped root canals using WaveOne Gold and XP-endo Shaper systems, both supplemented or not with manual instrumentation. Twenty-four long oval-shaped canals of mandibular incisors were distributed into two groups according to the instrumentation: WaveOne Gold Primary or XP-endo Shaper systems. All root canals were manually instrumented with a size 25 K-file after automated preparation. The specimens were scanned by using a micro-CT device (17.42 µm) before and after automated preparation and manual instrumentation. The increased surface of the root canal and the percentage of untouched areas were assessed. Both WaveOne Gold and XP-endo Shaper systems increased the root canal surface and had similar untouched areas (p>0.05). Supplementary instrumentation increased the surface of the root canal and decreased the untouched walls (p<0.05). WaveOne Gold and XP-endo Shaper systems provided a similar preparation of long oval-shaped canals and manual instrumentation improved their preparation.

Resumo Este estudo comparou o preparo de canais radiculares ovais longos usando os sistemas WaveOne Gold e XP-endo Shaper, ambos complementados ou não com instrumentação manual. Vinte e quatro canais longos e ovais de incisivos inferiores foram distribuídos em dois grupos de acordo com a instrumentação: sistemas WaveOne Gold Primary ou XP-endo Shaper. Todos os canais foram instrumentados manualmente com uma lima K tamanho 25 após preparo automatizado. Os espécimes foram escaneados usando um dispositivo de micro-CT (17,42 µm) antes e após o preparo automatizado e instrumentação manual. O aumento de superfície do canal radicular e a porcentagem de áreas intocadas foram avaliadas. Ambos os sistemas WaveOne Gold e XP-endo Shaper aumentaram a superfície do canal radicular e apresentaram áreas intocadas semelhantes (p>0,05). A instrumentação complementar aumentou a superfície do canal radicular e diminuiu o percentual de áreas intocadas (p <0,05). Os sistemas WaveOne Gold e XP-endo Shaper tiveram o preparo de canais ovais longos semelhantes, e a instrumentação manual melhorou o preparo.

Determination of the minimum inhibitory concentration of four medicaments used as intracanal medication.

The aim of this study was to determine the minimum inhibitory concentration (MIC) of iodoform, calcium hydroxide, IKI (iodine potassium iodine) and CFC (ciprofloxacin, Flagyl (metronidazole) and calcium hydroxide) required to kill S. aureus, Pseudomonas aeruginosa, Enterococcus faecalis and B. fragilis. In the experiment, medicaments were added to bacterial species into test tubes, in 10 different concentrations. The MIC was the lowest concentration of the drug at which bacterial growth could not be observed. In this investigation, CFC was the most effective medicament against all bacteria. All drugs were able to eliminate E. faecalis and B. fragilis, while IKI was not effective against S. aureus. IKI and calcium hydroxide were not able to eliminate P. aeruginosa as well.

Evaluation of ethylenediaminetetraacetic acid (EDTA) solution and gel for smear layer removal.

The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P < 0.05) between Groups 1 and 2, and also between Groups 1 and 3. No difference was observed between Groups 2 and 3 (P > 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

Instrument Design May Influence Bacterial Reduction During Root Canal Preparation.

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.

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.

Influencia de la medicación intracanal con pasta de hidróxido de calcio en la penetración del cemento obturador / obturadorInfluence of intracanal medication with calcium hydroxide paste in the penetration of the shutter cement / Influência da medicação intracanal com pasta de hidróxido de cálcio na infiltração do cimento obturador

La eliminación del hidróxido de calcio en el conducto radicular es determinante para el éxito del tratamiento endodóntico, los remanentes pueden interaccionar negativamente con los selladores endodónticos aumen-tando las filtraciones y disminuyendo la calidad de la obturación. Objetivo: Evaluar el efecto de la medicación intraconducto con pasta de hidróxido de calcio en la penetración del cemento obturador en el interior de los túbulos dentinarios. Materiales y métodos: 20 raíces distales de molares superiores se instrumentaron uti-lizando el Sistema Wave One Large 40/.08. Se dividieron aleatoriamente en dos grupos: uno obturado con técnica de cono único y cemento Ah plus con rodamina-B y otro obturado con la misma técnica y cemento Ah plus con rodamina B, previa colocación por 15 días y remoción mediante recapitulación de la pasta de hidróxido de calcio. Posteriormente los dientes fueron cortados transversalmente y se realizaron fotomicro-grafías del tercio cervical, medio y apical a través de la técnica de microscopia confocal de barrido por láser. La profundidad máxima de penetración fue determinada a través del programa Image J. Resultados: El ce-mento sellador Ah plus presentó menores valores de penetración cuando fue empleada previamente la pasta de hidróxido de calcio como medicación intracanal (p<0,01). El tercio del conducto con mayor penetración fue el tercio cervical seguido por el tercio medio y por último el apical (p<0,01). Conclusión: Los remanentes de hidróxido de calcio disminuyen la penetración del cemento sellador Ah plus en los túbulos dentinarios en todos los tercios del conducto radicular.

The elimination of calcium hydroxide in the root canal is decisive for the success of endodontic treatment, the remnants can interact negatively with endodontic sealants increasing filtrations and decreasing the quality of the seal. Objective: To evaluate the effect of intra-duct medication with calcium hydroxide paste on the pen-etration of the sealing cement inside the dentinal tubules. Materials and methods: 20 distal roots of upper molars were instrumented using the Wave One Large 40 / .08 System. They were randomly divided into two groups: one sealed with a single cone technique and Ah plus cement with rhodamine-B and another sealed with the same technique and Ah plus cement with rhodamine B, previous placement for 15 days and removal by recapping the paste calcium hydroxide. Subsequently, the teeth were cut transversely and photomicro-graphs of the cervical, middle and apical third were performed using the laser scanning confocal microscopy technique. The maximum depth of penetration was determined through the Image J program. Results: The Ah plus sealing cement had lower penetration values when the calcium hydroxide paste was previously used as an intra-channel medication (p <0.01). The third of the duct with the highest penetration was the cervical third followed by the middle third and finally the apical (p <0.01). Conclusion: Remaining calcium hydroxide decreases the penetration of the sealing cement Ah plus in the dentinal tubules in all thirds of the root canal.

A eliminação do hidróxido de cálcio do canal radicular é determinante para o sucesso do tratamento endo-dôntico; os remanescentes podem interagir negativamente com os cimentos endodônticos, aumentando as filtrações e diminuindo a qualidade do selamento. Objetivo: Avaliar o efeito da medicação intracanal com pasta de hidróxido de cálcio na penetração do cimento de selamento no interior dos túbulos dentinários. Materiais e métodos: 20 raízes distais de molares superiores foram instrumentadas usando o sistema Wave One Large 40 /.08. Eles foram divididos aleatoriamente em dois grupos: um selado com técnica de cone único mais cimento Ah plus com rodamina-B e outro selado com a mesma técnica e cimento Ah plus com rodami-na-B, prévia colocação por 15 dias e remoção recolocação da pasta hidróxido de cálcio. Posteriormente, os dentes foram cortados transversalmente e fotomicrografias do terço cervical, médio e apical foram realizadas pela técnica de microscopia confocal de varredura a laser. A profundidade máxima de penetração foi de-terminada pelo programa Image J. Resultados: O cimento selante Ah plus apresentou menores valores de infiltração quando a pasta de hidróxido de cálcio foi utilizada anteriormente como medicamento intracanal (p <0,01). O terço do conduto com maior penetração foi o terço cervical, seguido pelo terço médio e finalmente o apical (p <0,01). Conclusão: O hidróxido de cálcio restante diminui a penetração do cimento selante Ah plus nos túbulos dentinários em todos os terços do canal radicular.

Bacterial removal promoted by 2 single-file systems: Wave One and One Shape.

INTRODUCTION: Different single-file systems are available for endodontic treatment; however, comparative studies are scarce. Thus, the present study evaluated bacterial reduction promoted by 2 single-file systems: Wave One (Dentsply Maillefer, Ballaigues, Switzerland) and One Shape (Micromega, Besancon, France). METHODS: Forty-five distobuccal root canals of upper molars sterilized with ethylene oxide were infected with Enterococcus 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 3 groups according to instrumentation (n = 15): Wave One, One Shape, and the crown-down manual technique (control group). The other 6 specimens without contamination were control asepsis. After instrumentation, samples were collected with the use of scraping and paper cones. The bacterial reduction was calculated, and then intragroup analysis was performed using the paired t test and intergroup analysis using analysis of variance (both at 5% significance). RESULTS: All techniques significantly reduced the number of bacteria in the root canal (P < .05), with no significant difference between them (P > .05). The aseptic control group did not show any bacterial growth. CONCLUSIONS: It can be concluded that the single-file systems Wave One and One Shape significantly reduce the bacterial number in the root canal and that there is no significant difference in their bacterial reduction abilities.