The comparative study of temperature rise, time consuming and cut quality among piezosurgery, conventional rotary instruments and Er: YAG laser in apicectomy.

OBJECTIVES: This study aimed to compare the temperature rise, time consuming and cut quality of apicectomy using three different methods. MATERIALS AND METHODS: Twenty-four single-rooted teeth were collected and divided into four groups operating apicectomy with a NINJA tip of a piezoelectric device (G1), a diamond bur with 300,000 rpm (G2), and Er: YAG laser at 200 mJ/ 30 Hz (G3) as well as 250 mJ/ 30 Hz (G4). The temperature elevation and time were recorded and the cut quality was evaluated via stereomicroscope and scanning electronic microscopy (SEM). RESULTS: The temperature increases for G1 was significantly higher than for G2. However, there was no significant difference between G1 and G2 with laser groups respectively. The median time for apicectomy was: 100.14s for G1, 22.65s for G2, 33.58s for G3, and 21.80s for G4. G1 is the most time-consuming group and there was no statistically significance in the comparisons with G2, G3 and G4. Cut quality was assessed by crack occurrence, smear layer formation and dentinal tubules exposed. The percentage of cracked teeth in G1 and G2 was 33.33% and for laser groups the percentage was 16.67% each. SEM showed that no smear layer formed and almost all dentinal tubules were exposed on resected surfaces for G3&G4, surfaces from G2 were partly covered by smear layer, and surfaces from G1 were fully covered by smear layer and with no dentinal tubules exposed. CONCLUSIONS: Er: YAG laser and conventional rotary instruments were safe and efficient for apicectomy and with a better cut quality when compared with piezoelectric equipment. Er: YAG laser could be a promising technique for apicectomy and further studies are necessary, especially larger sample in vivo investigations, to verify the feasibility of Er: YAG laser in endodontic surgery.

Chitosan nanoparticles, Rose Bengal-chitosan activated photodynamic therapy as final irrigant on pushout bond strength, smear layer removal efficacy and antibacterial effectiveness against E.faecalis.

AIM: Impact of final root canal disinfectants diode laser (DL), Rose Bengal photosensitizer (RBP), Chitosan Nanoparticles (CNPs), and CNPs modified RBP on Enterococcus faecalis (E.faecalis) survival rate, smear layer (SL) removal efficacy and push out bond strength (PBS) of resin sealer to the radicular dentin. MATERIAL AND METHOD: Single rooted seventy-five human mandibular premolar teeth were sectioned at a level of cementoenamel (CEJ) and root canal treatment was performed using a ProTaper rotary instrument. To assess the antibacterial efficiency E.faecalis inoculation was performed using a pour plate method. The samples were arbitrarily allocated into five groups based on the final disinfectant received (n = 15) Group-1 (NaOCl+17 % EDTA), Group-2 (NaOCl+DL), Group-3 (NaOCl+CNPs), Group-4 (NaOCl+RBP activated by DL) and Group-5 (NaOCl+CNPs-RBP activated by DL). SEM analysis for SL removal was performed on five specimens from each group. Root canal obturation and sectioning were performed at cervical, middle, and apical levels. PBS and failure mode were analyzed using a universal testing machine (UTM) and stereomicroscope respectively. The data was subjected to analysis using one-way analysis of variance (ANOVA) and Tukey's post hoc test. RESULT: Group 1 (NaOCl+17 % EDTA) (0.36 ± 0.01 CFU/mL) unveiled the maximum survival rate of tested bacteria. However, Group 5 (NaOCl+CNPs-RBP activated by DL) (0.11 ± 0.01 CFU/mL) displayed minimum survival of E.faecalis. The highest SL removal (1.44 ± 0.11) and bond integrity scores (12.23 ± 0.24 MPa) were recorded in the coronal section of Group 5 (NaOCl+ CNPs-RBP activated by DL) treated roots. However, the lowest removal of SL (3.15 ± 1.09) and PBS (7.24 ± 0.09 MPa) were recorded in Group 4 (NaOCl+RBP activated by DL) treated canals. CONCLUSION: CNPs-RBP activated by DL as the final irrigant provided satisfactory antibacterial activity, SL removal, and bond strength outcomes compared to other tested groups.

Dual- or single rinse? The tubular sealer penetration of endodontic chelating agents.

INTRODUCTION: In this study, we aimed to compare the effectiveness of various chelating agents, ethilenediaminetetraacetic acid (EDTA), citric acid (CA), and etidronic acid (HEDP) mixed in two different forms, in removing the smear layer and promoting the penetration of an endodontic sealer into the dentinal tubules of extracted single-rooted teeth. METHODS: The study used 75 teeth divided into five groups: 17% EDTA, 10% CA, 9% HEDP + NaOCl, 9% HEDP + distilled water (DW), and a control (DW) group. Scanning electron microscopy was used to assess smear layer removal and confocal laser microscopy was used to evaluate tubular sealer penetration at different depths from the apical tip. RESULTS: Sealer penetration was highest with 17% EDTA and 10% CA as compared with the other agents (p<0.001). At the cervical third, the sealer penetration for EDTA, HEDP + NaOCl, and HEDP + DW groups were significantly different than those in DW (p = 0.020). For the middle third, EDTA, CA, and HEDP + NaOCl groups were significantly higher than those of the DW group (p<0.001). Cervical-level values were significantly higher than apical-level values for HEDP + NaOCl, HEDP + DW, and DW (p<0.001). Smear layer removal was lower with 9% HEDP + DW than with 17% EDTA and 10% CA at all depths (p<0.001). A significancy in smear layer removal was observed between 10% CA and control (p = 0.015) in middle depth. CONCLUSION: Within the limitations of this study, highest values were seen in EDTA and CA in terms of sealer penetration and smear layer removal. In the light of these findings, the use of strong chelating agents highlights better clinical efficiency than dual-rinse or single HEDP irrigation.

Glycolic acid on push-out bond strength of fiber post and smear removal: an in vitro study.

This study aims to investigate glycolic acid (GA) as a final irrigant on push-out bond strength of fiber post and smear removal. Ninety mandibular premolars were stabilized with a silicone key and photographed, and canal cross-section was calculated by image processing software. Round canal morphology was selected. The specimens were divided into five groups (n = 18); 10%GA, 17%EDTA, NaOCl + 10%GA, NaOCl + 17%EDTA, and the control. Fifteen specimens were used for the push-out. Three specimens were evaluated using a scanning electron microscope after post space preparation. Two-way ANOVA and Chi-square were used for statistics. GA presented higher strength than EDTA (p < 0.05). The NaOCl + GA showed higher strength than the NaOCl + EDTA (p < 0.05). The highest values were observed in cervical and lowest in apical thirds (p < 0.05). The most failure type was between dentin and resin (p < 0.05). GA removed the smear in the post space including the apical third. The NaOCl + GA has superiority to NaOCl + EDTA on push-out strength. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA.

Effectiveness of a new endodontic irrigation system for removing smear layer and dissolving simulated organic matter.

OBJECTIVES: The study aimed to evaluate the potential for the dissolution of organic tissue in areas of simulated complexity and cleaning of root canal walls of the new iVac® endodontic irrigation system. MATERIAL AND METHODS: Thirty mandibular premolars were evaluated by scanning electron microscopy before and after biomechanical preparation. Then, they were distributed according to the final irrigation protocol into groups with conventional irrigation, ultrasonic agitation with metallic insert (UA), and iVac® system, and new photomicrographs were obtained. For tissue dissolution analysis, glass capillaries filled with catgut were attached to the cervical and apical thirds of twenty-one prototyped upper incisors. They were weighed before and after the previously mentioned irrigation protocols. The data were statistically compared with a significance level of 5%. RESULTS: The final irrigation provided greater cleaning of the root canal walls in the cervical, middle, and apical thirds of the root canals (P < 0.05), with no statistically significant difference between UA and iVac®, regardless of the analyzed thirds. Both ultrasonic irrigation protocols dissolved a significantly greater volume than the conventional irrigation protocol (P < 0.05), with no difference between the two protocols (P < 0.05). CONCLUSIONS: The iVac® system showed root canal wall cleaning and tissue dissolution similar to UA with a metallic insert, and both were superior to conventional irrigation. CLINICAL RELEVANCE: The new irrigation system iVac is more effective than conventional irrigation and has similar root canal wall cleaning and tissue dissolution to UA.

Does luminosity and smear layer influence 810 nm laser energy transmission through human dentine?

PURPOSE: The aim of this study was to evaluate the influence of luminosity values and smear layer on transmission characteristics of 810 nm near infrared laser energy through dentine, using extracted human teeth. METHODS: A total of 200 teeth treated with endodontic medicaments to cause discolouration (Ledermix, Doxypaste or Odontopaste) were selected, to give a range of values for tooth shade (luminosity values). Sectioned teeth had smear layer created or removed. Near-infrared laser energy transmission was assessed using an 810 nm diode laser (90 mW, CW mode) with the tip placed at 2 mm and 4 mm from the external root surface, and a laser power metre. RESULTS: Both tooth shade and smear layer had independent attenuating effects. Transmission of laser energy was significantly lower in teeth with darker shades. There was a strong positive correlation between relative luminosity (lighter tooth colour) and transmitted laser power (r = 0.9271 for the Spearman rank correlation, P = 0.0022). When a smear layer was present, this significantly reduced the transmission of laser energy through the sample, compared to when no smear layer was present. CONCLUSION: The results of this laboratory study highlight the attenuating influence of a darker tooth shade and the presence of smear layer on the transmission of 810 nm light when directed onto the surface of human dentine. Such effects may be relevant to photo biomodulation, Photodynamic Therapy and other dental laser treatments.

Effect of Glycolic Acid, Maleic Acid, and EDTA in the Removal of Smear Layer from Root Canal Dentin

ABSTRACT Objective: To assess the efficacy of 5% Glycolic Acid (GA), 17% ethylenediaminetetraacetic acid (EDTA) and 7% maleic acid (MA), in removing the smear layer (SL). Material and Methods: For the experiment, forty single-rooted human teeth were selected. To perform the chemo‑mechanical preparation, the root canals were instrumented to an apical size of #30, along with simultaneous irrigation of 2.5% NaOCl. The samples were allotted to the experimental groups based on the final irrigating solution (n=10): (1) The GA group: 05%, (2) the EDTA group: 17%, (3) the MA group: 7%, and (4) the control group: Distilled water. The teeth were evaluated for the presence or absence of SL using SEM. Results: Comparing the 5% GA, 7% MA and 17% EDTA groups, no statistically significant differences were found at the coronal and middle thirds (p>0.05). However, in the apical third, MA had greater efficacy than EDTA (p=0.002) and GA (p=0.041), with a significant difference in the SL removal, while there was no significant difference between the latter (p=0.148). Conclusion: Thus, it was concluded that 7% maleic acid as a final irrigating solution is more efficacious than 17% EDTA and 5% glycolic acid in eliminating the smear layer from the apical portion of the root canal.

An in vitro comparative assessment of manual hand file, rotary protaper ni-ti, erbium:yttrium-aluminum-garnet laser, canal brush, and ultrasound methods for smear layer removal.

Background: Selection of instruments is important to prevent any complications such as ledge formation and instrument breakage. The main drawback linked with instrumentation is smear layer formation. Objectives: This study was done for comparison of manual hand file, rotary ProTaper Ni-Ti, erbium:yttrium-aluminum-garnet (Er:YAG) laser, ultrasound, and CanalBrush (CB) methods for smear layer removal. Methodology: Sixty freshly extracted single-rooted mandibular first premolars extracted for orthodontic treatment purpose were selected and classified into six groups. Group I was negative control in which no final agitation of irrigant was performed. In Group II, solution activation was performed with ProTaper Universal System, in Group III, solution activation was done with canal brush, in Group IV, ultrasound activation was done, in Group V, solution agitation was performed with Er:YAG laser agitation, and in Group VI, canal preparation with hand files was performed. Smear layer score was evaluated after canal preparation with each method. Results: Score 1 was seen in 3 (30%) in Group IV and 6 (60%) in Group V, score 2 was seen in 3 (30%) in Group I, 8 (80%) in Group II, 7 (70%) in Group III, 5 (50%) in Group IV, 3 (30%) in Group V, and 4 (40%) in Group VI. Score 3 was observed in 7 (70%) in Group I, 2 (20%) in Group II, 3 (70%) in Group III, 2 (20%) in Group IV, 1 (10%) in Group V, and 6 (60%) in Group VI. A statistically significant difference was found in smear layer removal score in all groups (P < 0.05) except between Group I versus VI (P > 0.05). Conclusion: Complete removal of the smear layer was not observed in any of the methods used in the study; however, Er: YAG laser was found to be better as compared to other methods.

Résumé Contexte: La sélection des instruments est importante pour éviter toute complication telle que la formation de rebords et la rupture d'instruments. Les Le principal inconvénient lié à l'instrumentation est la formation d'une couche de frottis. Objectifs: Cette étude a été réalisée pour comparer des limes manuelles, méthodes rotatives ProTaper Ni-Ti, laser erbium:yttrium-aluminium-grenat (Er:YAG), ultrasons et CanalBrush (CB) pour l'élimination des frottis. Méthodologie: Soixante premières prémolaires mandibulaires monoracinaires fraîchement extraites à des fins de traitement orthodontique ont été sélectionnées et classés en six groupes. Le groupe I était un témoin négatif dans lequel aucune agitation finale de l'irrigant n'a été effectuée. Dans le groupe II, l'activation de la solution a été réalisée avec le système universel ProTaper, dans le groupe III, l'activation de la solution a été effectuée avec une brosse canalaire, dans le groupe IV, l'activation par ultrasons a été fait, dans le groupe V, l'agitation de la solution a été effectuée avec une agitation au laser Er:YAG, et dans le groupe VI, la préparation du canal avec des limes manuelles a été effectué. Le score de la couche de frottis a été évalué après la préparation du canal avec chaque méthode. Résultats: le score 1 a été observé chez 3 (30 %) dans le groupe IV et 6 (60 %) dans le groupe V, le score 2 a été observé chez 3 (30 %) dans le groupe I, 8 (80 %) dans le groupe II, 7 (70 %) dans le groupe III, 5 (50 %) dans le groupe IV , 3 (30%) dans le groupe V, et 4 (40 %) dans le groupe VI. Le score 3 a été observé chez 7 (70 %) dans le groupe I, 2 (20 %) dans le groupe II, 3 (70 %) dans le groupe III, 2 (20 %) dans Groupe IV, 1 (10 %) dans le groupe V et 6 (60 %) dans le groupe VI. Une différence statistiquement significative a été trouvée dans le score d'élimination des frottis dans tous les groupes (P < 0,05) sauf entre le groupe I et VI (P > 0,05). Conclusion: L'élimination complète de la frottis n'a été observée dans aucun des méthodes utilisées dans l'étude; cependant, le laser Er:YAG s'est avéré meilleur par rapport aux autres méthodes. Mots-clés: Brosse canalaire, erbium : laser yttrium-aluminium-grenat, ProTaper, frottis, ultrasons.

In vitro assessment of interaction between lidocaine hydrochloride and irrigating solutions on root canal dentin: a scanning electron microscope study / Evaluación in vitro de la interacción entre el clorhidrato de lidocaína y las soluciones de irrigación en la dentina del conducto radicular: un estudio con microscopio electrónico de barrid

Aim: To investigate the precipitate formed from the interaction between 2% lidocaine hydrochloride with adrenaline (LA) with 2.5% sodium hypochlorite (NaOCl) and 0.2% chitosan nanoparticles on root canal dentin, using scanning electron microscopy (SEM). Material and Methods: Sixty mandibular premolars were decoronated, and the root length standardised. The specimens were randomly distributed into the following groups: Group 1 (control): 2% LA mixed with sterile water without root canal instrumentation, Group 2: 2% LA with 2.5% NaOCl in water without root canal instrumentation, and Group 3: 2% LA with 0.2% chitosan nanoparticles in water without root canal instrumentation. Teeth specimens were split and subjected to SEM analysis at cervical, middle, and apical root thirds. On observing precipitate formation in Group 2, 10 premolars were decoronated and treated with 2% LA and 2.5% NaOCl and subjected to root canal instrumentation. Results: Group 1 and Group 3 showed patent dentinal tubules and no precipitate formation. Group 2 showed precipitate blocking dentinal tubules in all the three sections, and the precipitate could not be removed completely after cleaning and shaping. Conclusion: NaOCl forms an insoluble precipitate on interaction with local anaesthetic solution that cannot be removed after chemo-mechanical preparation. Chitosan nanoparticles do not form any such precipitate and show patent dentinal tubules. Hence, chitosan can be used as a flushing irrigant.

Objetivo: Investigar el precipitado formado a partir de la interacción entre el clorhidrato de lidocaína al 2% con adrenalina (LA), el hipoclorito de sodio al 2,5% (NaOCl) y nanopartículas de quitosano al 0,2% en la dentina del conducto radicular, mediante microscopía electrónica de barrido (SEM). Material y Métodos: Se decoraron 60 premolares mandibulares y se estandarizó la longitud de la raíz. Los especímenes se distribuyeron aleatoriamente en los siguientes grupos: Grupo 1 (control): 2% la que fue mezclado con agua estéril sin instrumentación del conducto radicular, Grupo 2: 2% LA con 2,5% de NaOCl sin instrumentación del conducto radicular y Grupo 3: 2 % LA con 0,2% de nanopartículas de quitosano sin instrumentación del conducto radicular. Las muestras de dientes se dividieron y se sometieron a análisis SEM en los tercios radiculares cervical, medio y apical. Al observar la formación de precipitado en el Grupo 2, 10 premolares fueron decorados y tratados con LA al 2% y NaOCl al 2,5% y sometidos a instrumentación de conductos radiculares. Resultado: El Grupo 1 y el Grupo 3 mostraron túbulos dentinarios permeables y sin formación de precipitados. El grupo 2 mostró precipitado que bloqueaba los túbulos dentinarios en las tres secciones, y el precipitado no se pudo eliminar por completo después de limpieza y conformación. Conclusión: el NaOCl forma un precipitado insoluble al interactuar con la solución anestésica local que no se puede eliminar después de la preparación quimiomecánica. Las nanopartículas de quitosano no forman ningún precipitado de este tipo y muestran túbulos dentinarios permeables. Por lo tanto, el quitosano se puede utilizar como irrigante para el lavado.

Herbal Agents versus Ethylene Diamine Tetra Acetic Acid on Removal of the Smear Layer-A Systematic Review of In Vitro Studies.

This systematic review aimed to compare the efficacy of herbal agents with ethylene diamine tetraacetic acid (EDTA) in removing the smear layer during root canal instrumentation. The research question in the present study was to assess: "Is there a significant difference in reducing smear layer comparing EDTA and herbal agents?" Electronic databases (PubMed, Scopus, and Web of Science) were searched from their start dates to April 2022 using strict inclusion and exclusion criteria, and reviewed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines. Only in vitro studies comparing herbal agents with EDTA were included in the current systematic review. Two reviewers independently assessed the included articles. A total of 625 articles were obtained from an electronic database. Eighteen papers were included for review of the full text, out of which, ten papers were excluded because they did not meet the inclusion criteria. Finally, eight articles were included in the systematic review. The present systematic review considered only in vitro studies; hence, the result cannot be completely translated to strict clinical conditions. The results of the present systematic review have shown that quixabeira, morindacitrifolia, oregano extract, and neem show better smear layer removal compared to other herbal agents, whereas they showed reduced smear layer removal when compared with EDTA. Although, it was seen that most of the included studies did not report a high quality of evidence. Hence, the present systematic review concludes that herbal agents have reported to show inferior smear layer removal when compared to EDTA. Thus, as far as herbal based alternatives are concerned, there is no highest level of evidence to state its real benefit when used as a chelating root canal irrigant.

Effect of irrigation protocols on chemical smear layer formation over the post-space dentin.

This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n = 10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p = .05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p < .05), but without difference between them (p > .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p > .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p > .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

Lineamientos para el uso de terapias pulpares en dientes primarios con pulpas no-vitales / Diretriz sobre o uso de terapia pulpar devitalizada para dentes decíduos / Guidelines for the use of pulp therapy in primary teeth with non-vital pulps

Objetivo: Presentar lineamientos basados en evidencia para el tratamiento de pulpas no vitales debidas a caries profundas o traumatismos en dientes primarios. Métodos: el Grupo de Trabajo de la Academia Americana de Odontología Pediátrica AAPD realizó una revisión sistemática/meta-análisis de estudios acerca de terapia para pulpa no vital en dientes primarios, producto de caries o trauma, usando el enfoque GRADE para determinar el nivel de certeza de la evidencia para recomendaciones clínicas. Resultados: La determinación de GRADE fue de elevada a muy baja. Al comparar dientes con o sin resorción radicular, el éxito de la pulpectomía fue mayor (p<0,001) en los que no presentaban resorción radicular antes del tratamiento. El éxito de las pulpototmías obturadas con ZO/yodoformo/HC EndoflasTM(Laboratorios Sanlor, Cali, Colombia) y ZOE (óxido de zinc con eugenol) no fue diferente al yodoformo(yodoformo + hidróxido de calcio, VitapexTM o MetapexTM) después de 18 meses (p= 0,55); sin embargo el éxito de ZO/iodoformo/HC y ZOE fue cercano al 90% mientras que el del yodoformo fue 71% o menor. El análisis de red demostró que ZO/iodoformo/HC y ZOE son mejores que yodoformo. ELRP fue mejor que pulpectomía (p<0,001) en dientes con resorción radicular previa al tratamiento, pero la pulpectomía fue superior si las raíces estaban íntegras (p= 0,09). La instrumentación de los conductos radiculares fue significativamente más rápida (p<0,001) que la instrumentación manual, pero la calidad de la obturación no presentó diferencia (p= 0,09) y ambas técnicas presentaron éxito similar. El análisis de red clasificó al ZO/iodoformo/HC como mejor, ZOE en segundo lugar, y yodoformo en último lugar a los 18 meses. La tasa de éxito no fue impactada por el método de obturación, método de determinación de la longitud radicular, tipo de diente, número de citas, agentes de irrigación, remoción de la capa de desechos dentinarios o momento/tipo de restauración definitiva. Conclusiones: La tasa de éxito a 18 meses para pulpectomías demuestran que ZO/iodoformo/HC y ZOE son superiores al yodoformo. Las indicaciones de ELRP están limitadas a dientes con resorción radicular y requiere la realización de un seguimiento cercano.

Objetivo: Apresentar uma orientação baseada em evidência para terapias pulpar não vitais de cárie profundas ou trauma em dentes deciduos. Métodos: Um grupo de trabalho da AAPD realizou uma revisão/análise sistemática para estudos não vitais de dentes deciduos resultantes de trauma ou cárie e utilizou a abordagem GRADE para avaliar o nível de certeza de evidência para recomendações clínicas. Resultados: O GRADE foi avaliado de nível alto à muito baixo. Comparando os dentes com/sem reabsorção radicular, o sucesso da pulpectomia foi melhor (p<0,001) naqueles sem reabsorção radicular pré-operatória. OZ/iodofórmio/HC (óxido de zinco + iodofórmio + hidróxido de cálcio; EndoflasTM) e OZE (óxido de zinco e eugenol) o sucesso da pulpectomia não diferiu do iodofórmio (iodofórmio + hidróxido de cálcio; VitapexTM, MetapexTM) (p= 0,55) após 18 meses; contudo, as taxas de sucesso de OZ/iodofórmio/HC e OZE permaneceram perto de 90% enquanto que o iodofórmio foi de 71% ou menos. As taxas de análise da rede mostraram que o OZ/iodofórmio/HC e OZE era melhor do que o iodofórmio. LERT foi melhor (p<0,001) do que a pulpectomia nos dentes com reabsorção radicular pré-operatória, mas os resultados da pulpectomia foram melhores (p= 0,.09) se as raízes estivessem intactas. A instrumentação rotatória dos canais radiculares foi significativamente mais rápida (p<0,001) do que manual, mas a qualidade do preenchimento não diferiu (p= 0.09) e ambos tiveram sucesso comparável. A análise de rede classificou OZ/iodofórmio/HC como o melhor, OZE segundo, e iodofórmio como o mais baixo aos 18 meses. As taxas de sucesso não foram influenciadas pelo método de obturação ou determinação do comprimento da raiz, tipo de dente, número de visitas, irrigantes, remoção da lama dentinária, ou tempo/tipo de restauração final. Conclusões: As taxas de sucesso da pulpectomia de 18 meses favoreceram pulpectomias com OZ/iodofórmio/HC e OZE sobre iodofórmio. O LERT demonstrou indicação limitada para dentes com raízes reabsorvidas e requer um acompanhamento assíduo.

Abstract: Purpose: To present an evidence-based guideline for non-vital pulp therapies due to deep caries or trauma in primary teeth. Methods: The authors, working with the American Academy of Pediatric Dentistry, conducted a systematic review/meta-analysis for studies on non-vital primary teeth resulting from trauma or caries and used the GRADE approach to assess level of certainty of evidence for clinical recommendations. Results: GRADE was assessed from high to very low. Comparing teeth with/without root resorption, pulpectomy success was better (P<0.001) in those without preoperative root resorption. Zinc oxide plus iodoform plus calcium hydroxide ([ZO/iodoform/CH]; EndoflasTM) and zinc oxide and eugenol (ZOE) pulpectomy success did not differ from iodoform (iodoform plus calcium hydroxide; VitapexTM, MetapexTM) (P=0.55) after 18-months; however, ZO/iodoform/CH and ZOE success rates remained near 90 percent while iodoform was 71 percent or less. Network analysis ratings showed ZO/iodoform/CH and ZOE better than iodoform. Lesion sterilization tissue repair (LSTR) was better (P<0.001) than pulpectomy in teeth with preoperative root resorption, but pulpectomy results were better (P=0.09) if roots were intact. Rotary instrumentation of root canals was significantly faster (P<0.001) than manual, but the quality of fill did not differ (P=0.09) and both had comparable success. Network analysis ranked ZO/iodoform/CH the best, ZOE second, and iodoform lowest at 18 months. Success rates were not impacted by method of obturation or root length determination, type of tooth, number of visits, irrigants, smear layer removal, or timing/type of final restoration. Conclusions: Pulpectomy 18-month success rates supported ZO/iodoform/CH and ZOE pulpectomy over iodoform.

Adhesión a dentina part II: estrategias para optimizar la adhesión a dentina y protocolos adhesivos / Dentin bonding part II: strategies to optimize dentin bonding and adhesive protocols

La adhesión a dentina con sistemas adhesivos polimé-ricos representa un desafío que surge de la necesi-dad de vincular un sustrato dentario heterogéneo y variable con materiales que presentan todavía cier-tos aspectos a atender para poder conseguir el máxi-mo desempeño. El propósito del presente artículo es evaluar algunas de las estrategias propuestas para mejorar la adhesión a dentina, y sugerir un protocolo de trabajo con los diferentes tipos de sistemas adhesivos (AU)

Dentin bonding with polymeric adhesive systems represents a challenge that arises from the need to link a heterogeneous and variable dental substrate with materials that still have certain aspects to be addressed in order to achieve maximum performance. The aim of this article is to evaluate some of the proposed strategies to improve dentin bonding and to suggest a protocol for each different type of bonding systems (AU)

A Comparative Evaluation of Root Surface Biomodification with Erbium-Doped Yttrium Aluminum Garnet Laser, Ethylenediaminetetraacetic Acid Gel, and Titanium Nitride Curette: In Vitro Scanning Electron Microscope and Profilometry Analyses.

Objective: This study aims to evaluate the in vitro effects of different biomodification treatment methods on extracted tooth/root surfaces in terms of biologically acceptable changes favoring better periodontal healing. Background data: The use of various agents for root surface biomodification (RSB), during periodontal procedures is of critical importance to increase the success of the treatments through healing. Ethylenediaminetetraacetic acid (EDTA) is the most frequently used chemical RSB agent in periodontal clinical practice. Erbium-doped yttrium aluminum garnet (Er:YAG) lasers have well-known advantages on blood cell adhesion and fibrin network formation on root surfaces. Recently, novel titanium nitride (TIN) curettes are of great interest due to smoother surface changes obtained after their application. Materials and methods: Forty-four dentine specimens from extracted single-rooted teeth were randomly divided into four groups: Group 1: No treatment; Group 2: Er:YAG laser irradiation; Group 3: EDTA gel application; Group 4: TIN curette instrumentation. All specimen surfaces were wet polished before treatments. Before and after root surface roughness parameters of all specimens were assessed with a profilometer. Further, all scanning electron microscopy micrographs were analyzed and scored for root surface and smear layer morphology characteristics by two different blinded researchers. Results: There were no statistical differences between the initial roughness of all groups (p = 0.687). After treatments, EDTA gel group revealed an intact intertubular area, some smear debris on dentine surfaces, and partially occluded dentine tubules. Er:YAG laser created the highest roughness (p < 0.05) among all treatment groups with no smear layer and exhibited fully exposed dentine tubules and collagen fibrils. Surfaces instrumented with TIN curette were the smoothest (p < 0.05) and covered with a compact and thick smear layer. Conclusions: Within the limits of this study, Er:YAG laser-irradiated surfaces exhibited exposed collagen fibrils, and Er:YAG laser irradiation was found as the only method yielding the desired surface characteristics for better periodontal healing, where the fibrils are exposed in the absence of smear layer.

Efecto de los extractos fitoquímicos en la eliminación del barro dentinario en el tratamiento de conductos radiculares / Effects of phytochemical extracts on smear layer removal in root canal treatment

Introduction: Studies suggested that phytochemical products are considered potential solutions to smear layer removal due to their biological safety in cleaning root canal systems, lower toxicity, lower irritant effect and antimicrobial effect. Objective: The aim of the present study was to perform a systematic review to evaluate smear layer removal of root canal systems by different natural product solutions. Methods: systematic review. Search of the literature was performed on Pubmed, Scopus, Cochrane, Web of Science, Scielo and Google Scholar according the PRISMA protocol. Studies were included if they performed the experiments of smear layer removal on extracted permanent human teeth. Articles published in any language without restriction of year of publication were included in this review. The risk of bias assessment in the included studies was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies. The search strategy resulted in the retrieval of 6221 publications. After the eligibility criteria application, 8 articles were selected for analysis. Results: It was observed that some natural products solutions showed effects on smear layer removal, especially on coronal third. The phytochemical products such as Salvadora persica, chamomile alcohol extract and grape seed extract demonstrated good potential of smear layer removal, however, its effectiveness and clinical applicability are still unclear. Conclusions: Although the limitations of this study, it is possible to highlight those phytochemical products such as Salvadora persica, chamomile alcohol extract and grape seed extract that demonstrated good potential on SL removal(AU)

Introducción: Los productos fitoquímicos se consideran soluciones potenciales para la eliminación del barro dentinario debido a su seguridad biológica en la limpieza del sistema de conductos radiculares, menor toxicidad, menor efecto irritante y efecto antimicrobiano. Objetivo: Evaluar la eliminación del barro dentinario de los sistemas de conductos radiculares mediante diferentes soluciones de productos naturales. Métodos: La búsqueda de la literatura se realizó en Pubmed, Scopus, Cochrane, Web of Science, SciELO y Google Scholar, según el protocolo PRISMA. Los estudios se incluyeron si realizaron los experimentos de eliminación del barro dentinario en dientes humanos permanentes extraídos. En esta revisión se incluyeron artículos publicados en cualquier idioma, sin restricción de año de publicación. La evaluación del riesgo de sesgo en los estudios incluidos se evaluó mediante la lista de verificación de evaluación crítica del Instituto Joanna Briggs para estudios cuasiexperimentales. La estrategia de búsqueda resultó en la recuperación de 6221 publicaciones. Después de la aplicación de los criterios de elegibilidad, se seleccionaron 8 artículos para su análisis. Resultados: Se observó que algunas soluciones de productos naturales mostraron efectos sobre la eliminación del barro dentinario, especialmente en el tercio coronal. Los productos fitoquímicos como salvadora pérsica, extracto de alcohol de manzanilla y extracto de semilla de uva demostraron un buen potencial de eliminación del barro dentinario; sin embargo, su efectividad y aplicabilidad clínica aún no están claras. Conclusiones: A pesar de las limitaciones de este estudio, es posible destacar aquellos productos fitoquímicos como salvadora pérsica, extracto de alcohol de manzanilla y extracto de semilla de uva demostraron buen potencial de eliminación del barro dentinario(AU)

The presence of smear layer affects the antimicrobial action of root canal sealers.

AIM: To assess the chemical and microstructural characteristics of dentine after the use of two irrigation protocols and correlate this with the antimicrobial properties of hydraulic calcium silicate cement (HCSC) sealers and changes to the dentine structure/chemistry after sealer placement. METHODOLOGY: Two irrigation protocols - Protocol A using 2% NaOCl used 5 mL/5 min and Protocol B with 2% NaOCl (5 mL/5 min) followed by 17% EDTA (5 mL/3 min) - were used to prepare dentine. The chemical and microstructural changes following irrigation were assessed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy (n = 5) on dentine obtained from the mid-root and coronal parts of extracted human teeth. Four sealers (AH Plus, BioRoot, MTA Fillapex, TotalFill) were characterized by SEM/EDS (n = 3). The ability of the sealers to eradicate intratubular Enterococcus faecalis biofilms was assessed by live/dead dye and confocal laser scanning microscopy to measure the percentage of living cells. The effect of combined irrigation and root filling on dentine was assessed by SEM and EDS analysis (n = 5). Statistical analysis was undertaken using one-way anova and a number of post hoc tests to detect intergroup differences. The F-test was used for comparison of variances in the microbiology testing. RESULTS: The use of NaOCl alone left the smear layer intact, with traces of chlorine remaining on dentine. The use of BioRoot sealer restored the calcium levels of dentine which had been depleted by the irrigation with EDTA. BioRoot exhibited antimicrobial properties against intratubular bacteria even in the presence of smear layer (Protocol A). Smear layer removal improved the bactericidal effect of all sealers and Ca2+ leaching. The use of a chelating agent was important for the intratubular sealer penetration for AH Plus but not the other sealers. CONCLUSION: The removal of smear layer was necessary for penetration of AH Plus into the dentinal tubules. BioRoot was a more effective sealer in reducing the bacterial load in the dentinal tubules than the other materials tested and the presence of smear layer did not affect its activity.

Effect of Optimized Irrigation With Photon-Induced Photoacoustic Streaming on Smear Layer Removal, Dentin Microhardness, Attachment Morphology, and Survival of the Stem Cells of Apical Papilla.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the effect of optimized irrigation with photon-induced photoacoustic streaming (PIPS) activation of different irrigants (distilled water or ethylenediaminetetraacetic acid [EDTA]) on smear layer removal, dentin microhardness, attachment morphology, and survival of stem cells of the apical papilla (SCAP) in an organotypic root canal model. STUDY DESIGN/MATERIALS AND METHODS: A total of 144 standardized root segments were randomly allocated into 6 groups for irrigation: (i) NaOCl group, (ii) NaOCl + EDTA group, (iii) NaOCl + PIPS (distilled water) group, (iv) NaOCl + PIPS (EDTA) group, (v) NaOCl + EDTA + PIPS (distilled water) group, and (vi) NaOCl + EDTA + PIPS (EDTA) group. Each group was divided into four subgroups for assessment: (i) dentin cleanliness; (ii) dentin microhardness; (iii) cell attachment morphology; and (iv) viable SCAP quantification. RESULTS: Compared with the control groups, the NaOCl + EDTA + PIPS (EDTA) group showed higher efficiency in smear layer removal and in increasing SCAP viability with more stretched cellular morphology. There were no statistically significant differences in either smear layer removal effect, dentin microhardness, attachment morphology, or survival of SCAP among the other groups when optimized with PIPS (distilled water or EDTA) (P > 0.05). CONCLUSIONS: Our findings indicated that irrigation optimized with PIPS activation of EDTA for 40 seconds was conducive to smear layer removal without additional dentin microhardness decrease. Additionally, this irrigation created more cell-friendly dentin conditioning than other approaches, which was beneficial for the attachment and survival of SCAP. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Comparison of irrigant activation devices and conventional needle irrigation on smear layer and debris removal in curved canals. (Smear layer removal from irrigant activation using SEM).

AIM: To compare the effectiveness of smear layer and debris removal in the final rinse of curved canals of permanent molars using different commercially available irrigant activation devices. METHODS: The mesial roots of 74 extracted maxillary and mandibular molars were instrumented using the Mtwo nickel-titanium rotary system (VDW GmbH, Munich, Germany). They were then randomly assigned to one of three groups, varying in their final rinse protocol. Group 1 (n = 15) - conventional needle irrigation with 4% NaOCl; Group 2 (n = 19) - EndoActivator® (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) with 4% NaOCl; Group 3 (n = 17) - XP-endo® Finisher (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) with 4% NaOCl. After the final rinse, all canals were flushed with 1 mL 15% EDTA for 60 s and then flushed with saline. The roots were split longitudinally and prepared for scanning electron microscope imaging. ImageJ for Windows was utilised to assess the images for smear layer removal, while two blinded investigators assessed debris presence in the middle and apical thirds using a 5-point scale. RESULTS: There was no significant difference in smear layer and debris removal between treatment and control groups in the same canal zones. A significant difference was noted across different canal zones both within and across the groups. CONCLUSION: There is no statistically significant difference in effectiveness between activated irrigation techniques and manual activation. Further investigations are required to evaluate all methods available and determine the most efficient technique to irrigate successfully.

In vitro study on conditioned dental root surfaces: evaluation of wettability, smear layer, and blood clot adhesion.

OBJECTIVES: The aim was to investigate the efficacy of citric acid and ethylenediaminetetraacetic acid (EDTA)-based treatments on smear layer removal and blood clot formation and stabilization. METHOD AND MATERIALS: After scaling and root planing, 126 root samples were divided into seven groups treated with: deionized water; saline; citric acid solution; Ultradent Citric Acid gel; EDTA solution; EDTA-based PrefGel; or untreated. Each group was divided into three subgroups: I for the evaluation of smear layer removal and surface wettability, II and III for the evaluation of blood clot formation and stabilization in static or dynamic rinsing conditions. RESULTS: Conditioning agent treatments increased surface wettability with respect to untreated samples (Ultradent: 45 ± 1 degrees, P = 6.2 × 10-3; EDTA: 36 ± 5 degrees, P = 8.9 × 10-7; PrefGel: 47 ± 7 degrees, P = 3.2 × 10-2). Smear layer removal (30% to 60% with respect to untreated samples) was observed for all the conditioning agents. Clot was absent on untreated samples and samples treated with deionized water. Clot quality was significantly higher for samples treated with conditioning agents (P < .05) and similar between group II and III (P > .05). A statistically significant difference (P = .027) was observed for clot coverage of the saline group, comparing static and dynamic rinsing, confirming the positive effect of treatments on clot stabilization. CONCLUSIONS: The use of conditioning agents improves smear layer removal and clot formation and stabilization with respect to scaling and root planing procedure only, which is, however, considered an essential procedure to promote wound healing in periodontal surgery.

[Comparison of the clinical value of three reciprocating single nickel-titanium instruments in preparation of simulated curved root canals].

PURPOSE: To explore the application value of three reciprocating single nickel-titanium instruments in preparation of simulated curved root canals. METHODS: One hundred and fifteen single-curved resin simulation root canals were selected and divided into Reciproc group (group A, 28), One file group (group B, 29), Wave One group (group C, 29) and control group (group D, 29) by random graph method. The simulated root canals were prepared according to the specifications of the instructions, root canal preparation, resin removal, root canal cleaning effect, center positioning ability and root canal width were compared. SPSS 22.0 software package was used for statistical analysis. RESULTS: There was no significant difference in quality and curvature among four groups(P＞0.05). The difference in root canal preparation time among the four groups was statistically significant (P＜0.05), and the root canal preparation time in group B was the shortest(P＜0.05). Comparison of resin removal at the root canal orifice and the midpoint of the bending start point among four groups, the difference was statistically significant(P＜0.05). The root canal wall debris scores and smear layer scores in four groups were significantly different(P＜0.05). Compared with group A, B and D, the root canal wall debris scores of the crown, middle and tip of group C were the lowest, the scores of smear layer on the crown and middle of the root canal wall was the lowest(P＜0.05). There was no significant difference in the center positioning ability of the four groups at 5 mm, 6 mm and 7 mm from the apical foramen(P＞0.05). There was no significant difference in root canal width among four groups (P＞0.05). CONCLUSIONS: Reciproc, One file and Wave One reciprocating single nickel-titanium instruments can maintain the original shape of the simulated root canal. Compared with Reciproc and Wave One, One file has better root canal shaping ability and cleaning effect.