Effect of different obturation techniques on sealer penetration into dentinal tubules after final irrigation with XP-Endo finisher file

The first objective of this research was to evaluate the effectiveness of XP-Endo Finisher on dentinal tubule penetration of irrigation solution using confocal laser scanning microscopy. The main purpose of this research was to compare the effect of cold lateral condensation, continuous wave obturation and core-carrier based techniques on sealer penetration. Sixty mandibular premolars were prepared and allocated into two experimental groups (n=30) as the final irrigation technique and obturation technique experiment. In the final irrigation technique experiment, final irrigation was performed with XP-Endo Finisher, passive ultrasonic irrigation (PUI) and conventional needle irrigation (CNI) (n=10). The roots in the obturation technique experiment were also assigned into 3 groups and obturated with cold lateral condensation, continuous-wave obturation and core-carrier techniques (n=10). The most effective activation method, which emerged as a result of the first part of this study, was used as the final irrigation method in the obturation technique experiment. Then, all roots were sectioned in 1-mm-thick slices at 3mm from the apex for scanning. In terms of depth and percentage of material penetration, CNI exhibited significantly the lowest values and no significant difference was found between others. Also, there was no significant difference among obturation methods. In conclusion, XP-Endo Finisher and PUI are more effective than CNI on irrigant penetration. Sealer penetration into dentinal tubules is independent of obturation techniques.

El objetivo principal de esta investigación fue evaluar la eficacia de XP- Endo Finisher en la penetración de la solución de irrigación en los túbulos dentinarios mediante microscopía de láser confocal. Se prepararon sesenta premolares mandibulares y se distribuyeron en dos grupos experimentales (n=30) según el tipo de método de evaluación utilizado. En el experimento de la técnica de irrigación final, la irrigación final se realizó con XP-Endo Finisher, irrigación ultrasónica pasiva (PUI) e irrigación con aguja convencional (CNI) (n=10). Las raíces en el experimento de la técnica de obturación también se asignaron en 3 grupos y se obturaron con técnicas de condensación lateral fría, obturación de onda continua y portador de núcleo (n=10). El método de activación más eficaz, que surgió como resultado de la primera parte de este estudio, se utilizó como método de irrigación final en el experimento de la técnica de obturación. Luego, todas las raíces se seccionaron en muestras de 1mm de espesor. En términos de profundidad y porcentaje de penetración del material, CNI exhibió significativamente los valores más bajos y no se encontraron diferencias significativas entre los demás. Además, no hubo diferencias significativas entre los métodos de obturación. En conclusión, XP-Endo Finisher y PUI son más efectivos que CNI en la penetración del irrigante. La penetración del sellador en los túbulos dentinarios es independiente de las técnicas de obturación.

Study on the effect of ultrasound intermediate frequency acupoint drug guiding technology on the recovery of gastrointestinal function in patients undergoing lumbar spine surgery / 中国医师进修杂志

Objective:To observe the effects of ultrasound intermediate frequency acupoint targeted drug guiding technology on the recovery of gastrointestinal function and serum gastrin levels in elderly patients after lumbar spine surgery under general anesthesia.Methods:This study used prospective research methods.A total of 90 elderly patients undergoing lumbar spine surgery after general anesthesia in the orthopaedic ward of Beijing Geriatrics Hospital from June 2019 to June 2021 were randomly divided into blank control group, drug control group, and drug-guided treatment group, with 30 cases each group. After the operation, no intervention was given to the blank control group, the drug control group received oral mosapride citrate tablets, the drug-guided treatment group used the D patch to guide the medicine at the two acupoints of Zusanli and Zhongwan with ultrasound medium frequency guided medicine instrument for 1 week each. The serum gastrin levels of the patients in each group were detected 1 d before operation, 3 d after operation, and 1 week after operation, and the time of first exhaust and first defecation after operation were recorded.Results:The results showed that the level of serum gastrin preoperativein the three groups was not significantly different ( P>0.05). On the third day after operation, the levelof serum gastrin in the drug guide treatment group, drug control group and blank control group were lower than those at 1 d before operation: (66.51 ± 5.34) ng/L vs. (69.36 ± 6.50) ng/L, (58.34 ± 5.71) ng/L vs. (68.75 ± 5.13) ng/L, (55.76 ± 6.23) ng/L vs. (70.20 ± 6.71) ng/L, the differences were statistically significant ( P<0.05), and showed a decreasing trend in turn. Among them, the level of serum gastrin in the drug guide treatment group was higher than that in the drug control group and blank control group, the difference was statistically significant ( P<0.05). One week after operation, the level of serum gastrin in the three groups increased compared with the third day after operation ( P<0.05), and the drug guiding treatment group was higher than the drug control group and the blank control group: (72.38 ± 6.78) ng/L vs. (67.15 ± 6.27) ng/L, (63.52 ± 5.38) ng/L, the differences were statistically significant ( P<0.05). The time of first exhaust and defecation after the operation of the three groups of patients, the drug-guided treatment group was significantly shorter than the drug control group and the blank control group: (15.25 ± 3.10) h vs. (20.38 ± 4.21) h and (28.52 ± 3.69) h, (24.14 ± 3.53) h vs. (36.15 ± 3.54) h and (49.51 ± 4.37) h, the differences were statistically significant ( P<0.05). Conclusions:Ultrasound intermediate frequency acupoint drug guiding technology can increase the patient′s serum gastrin level and promote the recovery of gastrointestinal function in elderly patients with lumbar spine surgery after general anesthesia.

Application progress of parallel artificial membrane permeation assay model in drug permeability screening of transdermal drug delivery system / 中国药房

The traditional model Franz diffusion cell method has always been the “gold standard” for evaluating the permeability of transdermal drug delivery system （TDDS） drug. However， in the high throughput screening of a large number of drug molecules， it has the disadvantages of low efficiency， high cost， difficulty to obtain isolated skin，poor reliability and large workload. The emergence of parallel artificial membrane permeation assay （PAMPA） model provides reliable pre-prediction data for the evaluation of permeability of TDDS drug. PAMPA model has been widely used in the permeability screening research of TDDS drugs and their preparations such as analgesics， local anesthetics， antioxidants， antipyretics， analgesics and anti-inflammatory drugs， vitamins， cholinesterase inhibitors， active ingredients of natural products， and has the characteristics of high reliability， good selectivity， high efficiency， low cost and data stability. PAMPA model has greatly improved the high throughput screening efficiency of TDDS drug permeability. With the extensive application and gradual maturity of this model， it will become a new and effective evaluation method in addition to the traditional evaluation model.

Reversing the PAI-1-induced fibrotic immune exclusion of solid tumor by multivalent CXCR4 antagonistic nano-permeator

Fibrosis is one of the key factors that lead to the immune exclusion of solid tumors. Although degradation of fiber is a promising strategy, its application was still bottlenecked by the side effects of causing metastasis, resulting in the failure of immunotherapy. Here, we developed an antimetastatic polymer (HPA) for the delivery of chemo-drug and antifibrotic siPAI-1 to form the nano-permeator. Nano-permeator shrank after protonation and deeply penetrated into the tumor core to down-regulate the expression of PAI-1 for antifibrosis, and further promoted the sustained infiltration and activation of T cells for killing tumor cells. Moreover, metastasis after fiber elimination was prevented by multivalent CXCR4 antagonistic HPA to reduce the attraction of CXCL12 secreted by distant organs. The administration of stroma-alleviated immunotherapy increased the infiltration of CD8+ T cells to 52.5% in tumor tissues, inhibiting nearly 90% metastasis by HPA in distant organs. The nano-permeator reveals the mechanism and correlation between antifibrosis and antimetastasis and was believed to be the optimizing immunotherapy for solid fibrotic tumors.

Recent progress in application of nanovaccines for enhancing mucosal immune responses

Mucosal vaccines that stimulate both mucosal and systemic immune responses are desirable, as they could prevent the invading pathogens at their initial infection sites in a convenient and user-friendly way. Nanovaccines are receiving increasing attention for mucosal vaccination due to their merits in overcoming mucosal immune barriers and in enhancing immunogenicity of the encapsulated antigens. Herein, we summarized several nanovaccine strategies that have been reported for enhancing mucosal immune responses, including designing nanovaccines that have superior mucoadhesion and mucus penetration capacity, designing nanovaccines with better targeting efficiency to M cells or antigen-presenting cells, and co-delivering adjuvants by using nanovaccines. The reported applications of mucosal nanovaccines were also briefly discussed, including prevention of infectious diseases, and treatment of tumors and autoimmune diseases. Future research progresses in mucosal nanovaccines may promote the clinical translation and application of mucosal vaccines.

The influence of sepsis on antimicrobials tissue penetration: The use of microdialysis technique to access free drug distribution

Abstract Sepsis is described as a life-threatening organ dysfunction caused by a host's response to infection, leading to an unbalance in body homeostasis. It is one of the leading causes of death in developed countries. Considering that in critically ill patients, such as those with sepsis, plasma concentrations do not necessarily reflect tissue concentrations, one way to assess tissue concentrations is through the microdialysis technique, which allows direct measurements of free drug at the site of action. This review was carried out after searching the Pubmed, Scielo and Web of Science databases, using the following descriptors: (microdialysis AND (sepsis OR septic shock OR severe sepsis OR septicemia)) OR (microdialysis AND (sepsis OR septic shock OR severe sepsis) OR septicemia) AND (antimicrobial OR antibiotic OR antifungal)). The physiological changes generated by sepsis may imply changes in pharmacokinetic parameters, such as in clearance, which may be reduced in these patients and in volume of distribution, which presents an expansion, mainly due to edema. Both events contribute to a high inter- individual variability in tissue penetration of antimicrobials which is generally observed in patients with sepsis.

Penetration ability and biological activity of fusion protein PTD4-Cu, Zn-SOD in human astrocytes in vitro by immunofluorescence test / 西安交通大学学报(医学版)

【Objective】 To observe the penetration and biological activity of PTD4-Cu, Zn-SOD into human astrocytes and whether it can mitigate hypoxia damages. 【Methods】 ①Immunohistochemistry and fluorescence test: We labeled the Cu, Zn-SOD by a monoclonal antibody, combined it with the fluorescent secondary antibody labeled with fluorescein isothiocyanate (FITC) to observe the effect of transduced PTD4-Cu, Zn-SOD on the viability of human astrocytes. ② The experimental group: After hypoxic damage model, the cells were divided into three groups: blank control, group Cu, Zn-SOD, and group PTD4-Cu, Zn-SOD. Group blank was added with DMEM medium (excluding serum) as control; DMEM medium was added to the other two for one hour (excluding serum) with its fusion proteins (Cu, Zn-SOD and PTD4 -Cu, Zn-SOD) with the final concentration of 2 μmoL/L. After the intervention, we used SOD and MDA test kits to observe PTD4-Cu, Zn-SOD and Cu, Zn-SOD in astrocytes after fusion protein intervention. 【Results】 The PTD4-Cu, Zn-SOD fusion protein could have aggregation distribution in the nucleus by FITC fluorescently labeled. After the intervention, it could increase the SOD activity in astrocytes in group PTD4-Cu, Zn-SOD and group Cu, Zn-SOD compared with control group, but the SOD activity was more obvious in the fusion proteins PTD4-Cu, Zn-SOD group. And the dose of MDA was reduced in group PTD4-Cu, Zn-SOD compared with group Cu, Zn-SOD and control group. 【Conclusion】 PTD4-Cu, Zn-SOD fusion protein can transcellular membrane of human astrocytes. The fusion protein PTD4-Cu, Zn-SOD can increase the SOD activity and reduce the content of MDA by human astrocytes from hypoxia injury.

The penetration effect of ultrasound and Er:YAG laser irrigation activation techniques on dentine of infected human root canals / 口腔疾病防治

Objective@#This ex vivo study evaluated the effect of ultrasound and Er:YAG laser irrigation activation techniques on the penetration of sodium hypochlorite solution into infected human root canal dentin, providing a reference for clinical infection control of infected root canals.@*Methods @#Thirty-six cases of infected root canals were collected and randomly divided into three groups according to the irrigation technique: 12 cases in the conventional syringe irrigation (CSI) group, 12 cases in the passive ultrasonic irrigation (PUI) group, 12 cases in the Er:YAG laser and photon-induced photoacoustic streaming (PIPS) group and 36 cases of clean root canals (12 cases in the CSI group, 12 cases in the PUI group, 12 cases in the PIPS group). All of the selected root canals were straight root canals of posterior teeth. After standardizing the root length, all canals were subjected to instrumentation and dynamic irrigation. 2% methylene blue solution was used to visualize the penetration of the irrigant. EXAKT cutting and grinding equipment was used to take transverse sections of 100-150 μm at the coronal, middle and apical thirds of the root canals. The data (maximum penetration depth, average penetration depth, and penetration percentage) were observed under a light microscope to evaluate the effect of dye penetration. @*Results @# With the three irrigation techniques, the maximum penetration depth, average penetration depth and penetration percentage of the infected root canals were significantly lower than those of clean root canals in the full length of the root canal (P<0.05). The penetration percentage, average penetration depth and maximum penetration depth of the PIPS group were significantly higher than those of the CSI group in the coronal, middle and apical thirds of the infected root canal, respectively (P<0.05). There was no significant difference in the maximum penetration depth, average penetration depth or penetration percentage between the PUI and CSI groups (P>0.05). There was also no significant difference in the maximum penetration depth, average penetration depth or penetration percentage between the PIPS and PUI groups (P>0.05). @*Conclusion @# The dentine permeability of infected root canals was weaker than that of clean root canals. Er:YAG laser-assisted irrigation activation technology could significantly improve the penetration of sodium hypochlorite solution into infected dentin, but passive ultrasonic irrigation did not significantly improve the penetration.

Mucus-penetrating nonviral gene vaccine processed in the epithelium for inducing advanced vaginal mucosal immune responses

Establishment of vaginal immune defenses at the mucosal interface layer through gene vaccines promise to prevent infectious diseases among females. Mucosal barriers composed of a flowing mucus hydrogel and tightly conjugated epithelial cells (ECs), which represent the main technical difficulties for vaccine development, reside in the harsh, acidic human vaginal environment. Different from frequently employed viral vectors, two types of nonviral nanocarriers were designed to concurrently overcome the barriers and induce immune responses. Differing design concepts include the charge-reversal property (DRLS) to mimic a virus that uses any cells as factories, as well as the addition of a hyaluronic acid coating (HA/RLS) to directly target dendritic cells (DCs). With a suitable size and electrostatic neutrality, these two nanoparticles penetrate a mucus hydrogel with similar diffusivity. The DRLS system expressed a higher level of the carried human papillomavirus type 16 L1 gene compared to HA/RLS in vivo. Therefore it induced more robust mucosal, cellular, and humoral immune responses. Moreover, the DLRS applied to intravaginal immunization induced high IgA levels compared with intramuscularly injected DNA (naked), indicating timely protection against pathogens at the mucus layer. These findings also offer important approaches for the design and fabrication of nonviral gene vaccines in other mucosal systems.

Medical micro- and nanomotors in the body

Attributed to the miniaturized body size and active mobility, micro- and nanomotors (MNMs) have demonstrated tremendous potential for medical applications. However, from bench to bedside, massive efforts are needed to address critical issues, such as cost-effective fabrication, on-demand integration of multiple functions, biocompatibility, biodegradability, controlled propulsion and in vivo navigation. Herein, we summarize the advances of biomedical MNMs reported in the past two decades, with particular emphasis on the design, fabrication, propulsion, navigation, and the abilities of biological barriers penetration, biosensing, diagnosis, minimally invasive surgery and targeted cargo delivery. Future perspectives and challenges are discussed as well. This review can lay the foundation for the future direction of medical MNMs, pushing one step forward on the road to achieving practical theranostics using MNMs.

Effect of three different conditioning agents on cavosurface microleakage and bond strength of glass ionomer restorations – An in vitro study

Aim: This study aimed to investigate the conditioning effects of phosphoric acid/5.25% sodium hypochlorite (NaOCl) mixture, 2% chlorhexidine (CHX) digluconate, and 10% polyacrylic acid on cavosurface microleakage and bond strength of glass ionomer (GI) restorations. Materials and Methods: Out of 68 extracted premolars, 34 teeth were selected for microleakage and 34 for bond strength evaluation. The samples were divided into the following four groups. Group 1: pretreatment with 50/50 volume% mixture of 5.25% NaOCl solution and 37% phosphoric acid (H3PO4), Group 2:pretreatment with 2% CHX digluconate, Group 3: pretreatment with 10% polyacrylic acid (positive control), and Group 4: no pretreatment (negative control). All the samples were then restored with glass ionomer cement (GIC). Microleakage was evaluated using a stereomicroscope and rhodamine-B dye penetration test. For bond strength, flat dentin surface was exposed and pretreated as mentioned previously and restored with GIC and was evaluated using universal testing machine. Results: Among all the four groups, Group 1 showed least microleakage and highest bond strength when compared with other groups. Whereas the Group 4 samples which were not pretreated with any of the conditioning agent showed the least shear bond strength with greatest cavosurface microleakage when compared to the groups which were pretreated with the conditioning agents. Conclusions: A combination of 50/50 volume % mixture of 37% H3PO4 and 5.25% NaOCl can be a good choice for surface pretreatment of GI restorations.

Evaluation of the dentinal tubule penetration of an endodontic bioceramic sealer after three final irrigation protocols

Introduction: This study aimed to evaluate the dentinal tubule penetration of an endodontic bioceramic sealer, Sealer Plus BC, after three final irrigation protocols. Methods: Thirty distobuccal roots of maxillary molars were selected. Root canal preparation was performed up to an #40.06 instrument (X1 Blue) under 2.5% sodium hypochlorite irrigation. Specimens were randomly divided into three groups (n=10), according to the final irrigation protocol: G-NaOCl (2.5% sodium hypochlorite + PUI), G-SS (0.9% saline solution + PUI) and G-H20 (Deionized water + PUI). After final irrigation protocols, all specimens were irrigated with phosphate buffer solution. Root canal obturation was performed using the single cone technique and Sealer Plus BC, stained with a specific fluorophore. Specimens were transversely sectioned and each root third was evaluated in a confocal scanning laser microscopy. Images obtained were analyzed for sealer penetration in the dentinal tubules. Results: Dentinal tubule penetration of Sealer Plus BC was not observed in any root third, regardless of the final irrigation protocol investigated. Conclusions: Sealer Plus BC dentinal tubule penetration was not observed after none of the protocols tested. Dentinal tubule penetrability of Sealer Plus BC may be related to other factors rather than the final irrigation protocol.

Simultaneous determination of LY3214996,abemaciclib,and M2 and M20 metabolites in human plasma,cerebrospinal fluid,and brain tumor by LC-MS/MS / 药物分析学报

A sensitive and rapid liquid chromatography tandem mass spectrometry(LC-MS/MS)method was established for the quantification of total and unbound concentrations of LY3214996,an extracellular signal-regulated kinase inhibitor;abemaciclib,a cyclin-dependent kinase 4/6 inhibitor;and abemaciclib active metabolites,M2 and M20,in human plasma,brain tumor,and cerebrospinal fluid samples.The method was validated over a concentration range of 0.2-500 nM within a total run time of 3.8 min using isocratic elution on a Kinetex? Fs column.Detection was performed on a Sciex QTRAP 6500+mass spectrometer employing multiple reaction monitoring mode under positive electrospray ionization.The intra-and inter-batch accuracy as well as the precision of the method for all matrices was within±20％and≤20％at the lower limit of quantification,and within±15％and≤15％for other quality control levels for all analytes.The unbound fractions of drugs and metabolites in spiked and patient samples were determined using an optimized equilibrium dialysis.The validated method was successfully applied in a phase 0/2 clinical trial to assess the central nervous system penetration of LY3214996 and abemaciclib.

Formulation development of anti-rheumatoid gel of Saraca asoca (Roxb. ) De Wilde hydroalcoholic extract containing eucalyptus oil and peppermint oil as penetration enhancer

Abstract In the present research investigation, various concentrations of hydro-alcoholic extract of Saraca asoca (Roxb.) De Wilde (family: Caesalpinaceae) dried bark and carbopol polymer at different temperature ranges were optimized for the preparation of gel formulation. Natural penetration enhancers, v.i.z., eucalyptus oil and peppermint oil were incorporated separately in the extract based gel formulations to study the rate of drug permeation across egg membrane, using franz diffusion cell. In vitro anti-arthritis potential of the formulations was also studied using inhibition of albumin denaturation, antiproteinase activity and membrane stabilization method. As per the results of current study, it is established that S. asoca dried bark hydroalcoholic extract based gel prepared using peppermint oil as penetration enhancer exhibited good permeation rate of 8.48% at the end of 3 h. The percentage inhibition of proteins by antiproteinase method at concentration of 50 µg/ml was 50.01±1.00% which was close to 53.92±0.99% as shown by the standard drug, Diclofenac. Also, the percent protein inhibition determined using membrane stabilization method was found to be 49.70±1.00%, however, it was 63.32±0.94% for the standard drug, Diclofenac. Hence, it is concluded that peppermint oil may act as a good candidate for the preparation of potent anti-rheumatic gel preparations.

Development of monolithic matrix type transdermal patches containing cinnarizine: Physical characterization and permeation studies

To overcome the problems associated with bioavailability and systemic side effects of the drug by oral administration, monolithic matrix type transdermal patches containing cinnarizine (CNZ) were developed. For this purpose, films based on hydroxypropyl methylcellulose and polyvinylpyrrolidone as matrix-forming polymers were designed. Physical characteristics of transdermal films and drug-excipient compatibility were investigated. Factors affecting in vitro drug release and ex vivo skin penetration and permeation of the drug were studied. It was confirmed that films displayed sufficient flexibility and mechanical strength for application onto the skin for a long time period. Ex vivo penetration experiments gave satisfactory results for transdermal drug delivery through rat skin. The parameters determining good skin penetration were also evaluated. The highest drug permeation rate was obtained with incorporation of Transcutol® (0.102 mg/cm2/h) into the base CNZ formulation, followed by propylene glycol (0.063 mg/cm2/h), menthol (0.045 mg/cm2/h), and glycerin (0.021 mg/cm2/h) as penetration enhancers (p < 0.05). As a result, the developed transdermal patches of CNZ may introduce an alternative treatment for various conditions and diseases such as idiopathic urticarial vasculitis, Ménière's disease, motion sickness, nausea, and vertigo. Thus, the risk of systemic side effects caused by the drug can be reduced or eliminated

Evaluation of copaiba oil as enhancer of ibuprofen skin permeation

Abstract The administration of medications on the skin through transcutaneous routes is a practice that has been used by mankind for millennia. Some studies have been reporting the use of terpenes and natural oils rich in terpenes as an enhancer of cutaneous penetration. Copaiba oil, due to its rich content of terpenes, presents itself as a great choice of penetration enhancer for drugs administered on the skin. In this study, we developed two cream formulations containing 5% of ibuprofen (IBU) and copaiba oil: IBCO5 and IBCO10 with 5% and 10% of copaiba oil respectively. Ex vivo cutaneous penetration/permeation studies of IBU were performed using pig ear skin as biological membrane in the Franz-type diffusion cells. The steady-state flux of IBU samples, IBCO5 (35.72 ± 6.35) and IBCO10 (29.78 ± 2.41) were significantly higher when compared with control without copaiba oil (10.32 ±1.52) and with a commercial product (14.44 ± 2.39). In the penetration analysis, the amount of IBU found in the samples IBCO5 and IBCO10 was markedly higher in the dermis than epidermis. Our results showed that copaiba oil possesses attracting properties in promoting skin penetration and permeation of IBU when added into cream formulations.

Research progress of delivery strategies related mucus barrier in mucosal drug delivery / 药学学报

The mucous barrier is a major physiological obstacle that the mucosal drug delivery system needs to deal with. In response to this physiological barrier, many achievements have been made in research of mucosal adhesion and mucus penetration. This review puts emphasis on the progress of the research on new mucosal adhesion strategies such as cationization, sulfhydrylization, maleimide functionalization, lectinization and catechol conjugation; polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly (2-alkyl-2-oxazoline) (POZ), zwitterionic polymers and other mucus-inert materials, strategies to enhance mucus penetration ability such as enzyme functionalization, reducing agent pretreatment and so on. The problems of each strategy are also analyzed and discussed, which can provide some references for clinical transformation.

Novel strategies for promoting tumor penetration of anticancer nanomedicines / 药学学报

There is a broad and urgent need for the clinical application of anticancer nanomedicine in tumor therapy, but the complex biological barrier in solid tumors has always been the main obstacle to infiltrating nanomedicine into the tumor. The traditional design of nanomedicine based on enhanced permeability and retention (EPR) effect still has some limitations in tumor permeability, it is urgent to find other design theories. Therefore, this review summarizes two novel strategies, active transcytosis and immune cell-mediated tumor penetration, for promoting tumor penetration of anticancer nanomedicine.

Capacidad de Penetración y Difusión de la Medicación, Intraconducto en Túbulos Dentinales, Conductos Laterales e Istmos. Una Revisión Sistemática

RESUMEN: El objetivo de la terapia endodóntica consiste en tratar o prevenir la periodontitis apical. La efectiva eliminación o disminución de microbiota es esencial para la reparación periapical. Debido a esto, se utiliza el empleo de medicamentos intraconductos para tratar químicamente el sistema de conductos radiculares, y cobra relevancia la capacidad de penetración y difusión de dicho medicamento para entrar en contacto directo con los microorganismos que penetren dentro de los túbulos dentinales, conductos laterales e itsmos. Se realizó una revisión de la literatura en bases de datos electrónicas con los buscadores "Pubmed, Scielo y Google Académico", utilizando palabras clave para identificar la literatura publicada relevante en inglés. El análisis y los criterios de elegibilidad se documentaron de acuerdo con los elementos de informe para revisiones sistemáticas y meta-análisis (Preferred Reporting Items for Systematic Reviews and Meta-Analysis, PRISMA). No se impusieron restricciones sobre la fecha de publicación. Se recogieron datos sobre capacidad de difusión de medicación intraconductos en túbulos dentinales, conductos laterales e itsmos radiculares y se sometieron a análisis descriptivo de datos. La búsqueda bibliográfica en bases de datos electrónicas según los criterios de inclusión arrojó 45 títulos y resúmenes. Entre ellos, 7 artículos fueron seleccionados. Se determinó un rango de penetración del medicamento muy variable, entre 27,7 - 2350 μm y rango de difusión de 200-500 μm. Hay pocos estudios publicados que reporten la capacidad de penetración y difusión de la medicación intraconductos. El vehículo empleado y diámetro de las partículas en la preparación del medicamento y la eliminación de la capa de desecho aumentaría la capacidad de penetración/difusión del medicamento intraconductos dentro del túbulo dentinal, conductos laterales e itsmo.

ABSTRACT: The objective of endodontic therapy is to treat or prevent apical periodontitis. The effective elimination or reduction of the microbiota is essential for periapical repair. Due to this, the use of intracanal drugs is used to chemically treat the root canal system, and the penetration and diffusion capacity of said drug becomes relevant to come into direct contact with the microorganisms that penetrate inside the dentinal tubules, lateral canals and isthmus. A literature review was carried out in electronic databases with the search engines "Pubmed, Scielo and Google Academic", using keywords to identify the relevant published literature in English. The analysis and eligibility criteria were documented according to the reporting items for systematic reviews and meta-analyzes (Preferred Reporting Items for Systematic Reviews and Meta-Analysis, PRISMA). No restrictions were placed on the date of publication. Data on intracanal drug diffusion capacity in dentinal tubules, lateral canals and root isthmus were collected and subjected to descriptive data analysis. The bibliographic search in electronic databases according to the inclusion criteria yielded 45 titles and abstracts. Among them, 7 articles were selected. A highly variable drug penetration range was determined, between 27.7 - 2350 μm and a diffusion range of 200-500 μm. There are few published studies that report the penetration and diffusion capacity of intracanal medication. The vehicle used and the diameter of the particles in the preparation of the drug and the elimination of the waste layer would increase the penetration / diffusion capacity of the drug within the dentinal tubule, lateral canals and isthmus.

Different biomechanical preparation protocols on the penetration and bond strength of the filling material to dentin

Abstract The aim of this study was to evaluate the influence of different instruments and mechanisms of agitation of the irrigating solution on the penetration by confocal laser scanning microscopy (CLSM), and the bond strength (BS) of the filling material to the dentin by push-out test. Human premolars were distributed in two experimental groups (n=30), according to the instrumentation system: ProTaper Next (PN) or XP-endo Shaper (XS) and three irrigation protocol (n=10): NaviTip (Nv), XP-endo Finisher (XF), passive ultrasonic irrigation/ XP-endo Finisher (PUIXF). The 2.5% NaOCl and 17% EDTA were the irrigating solutions used. The filling was performed using a lateral condensation technique, with AH Plus added to 0.1% rodhamine B. The roots were sectioned, obtaining 2 slices for each third of the root. The first slice was submitted to the sealer penetration analysis and the push-out test. The second slice was submitted to qualitative analysis (SEM) of the union interface. For the penetration (%) Tukey showed that PNXF (82.38±13.48), PNPUIXF (82.48± 12.02), XSXF (82.24±11.28) and XSPUIXP (86.23±10.45) presented the highest values, different (p<0.05) from PNNv (68.29±15.12) and XSNv (71.41±16.50). The BS (MPa) test evidenced that in the cervical third, PNPF (4.92±1.04) and XPSPF (5.03±0.70) obtained the highest values differing from the others groups (p<0.05). CSLM and SEM showed greater penetration of the sealer on the entire length of the root canal when the irrigation solution was stirred. In conclusion that the association PUI and XP-endo Finisher favored the penetration and bond strength of the filling material to the root dentin.

Resumo O objetivo neste estudo foi avaliar a influência de diferentes instrumentos e mecanismos de agitação da solução irrigadora na penetração e resistência de união (RU) do AH Plus à dentina. Pré molares humanos foram distribuídos em dois grupos experimentais (n=30), de acordo com o sistema de instrumentação: ProTaper Next (PN) ou XP-endo Shaper (XS) e de acordo com três protocolos de irrigação (n=10): NaviTip (Nv), XP-endo Finisher (XF), passive ultrasonic irrigation/ XP-endo Finisher (PUIXF). A irrigação do canal radicular foi realizada com NaOCl 2,5% e EDTA 17%. A obturação foi realizada por meio da técnica da condensação lateral, com AH Plus acrescido de rodhamina B 0,1%. As raízes foram seccionadas, obtendo-se 2 slices de 2,0 mm para cada terço radicular. O primeiro slice foi submetido a análise da penetração do cimento e ao teste de push-out e o segundo slice submetido a MEV para análise da interface de união. Para penetração (%) Tukey evidenciou que PNXF (82,38±13,48), PNPUIXF (82,48±12,02), XSXF (82,24±11,28) e XSPUIXF (86,23±10,45) apresentaram os maiores valores, diferentes (p<0,05) de PNC (68,29±15,12) e XPSC (71,41±16,50). Na RU (MPa) foi evidenciado que PNPF (4,92±1,04) e XPSPF (5,03±0,70), no terço cervical, obtiveram os maiores valores diferentes dos demais (p<0,05). MCVL e MEV evidenciaram maior penetração do cimento em toda extensão da parede do canal radicular inclusive nas regiões polares, quando foi realizada a agitação da solução irrigadora. Concluiu-se que a associação PUI e XP-endo Finisher favoreceu a penetração e resistência de união do material obturador à dentina radicular.