Antimicrobial and Antibiofilm Properties of Bioceramic Materials in Endodontics

Microbes are prevalent in the root canals of necrotic teeth, and they are the cause of primary and post-treatment apical periodontitis. Bacteria can dwell within the infected root canal system as surface-adherent biofilm structures, which exhibit high resistance to antimicrobial agents. Bioceramic materials, with their biocompatible nature and excellent physico-chemical properties, have been widely used in dental applications, including endodontics. This review focuses on the application of bioceramic technology in endodontic disinfection and the antibiofilm effects of endodontic bioceramic materials. Different bioceramic materials have shown different levels of antibiofilm effects. New supplements have emerged to potentially enhance the antibiofilm properties of bioceramics aiming to achieve the goal of microbial elimination in the root canal system.

Comparative evaluation of 5% sodium hypochlorite and Nd:YAG laser in reducing endotoxins level from infected root canals – An in vivo microbiological study

Objectives: Endodontic infection is one of the most challenging aspects of dental treatment which is primarily caused by Gram-negative anaerobic bacterial species. The primary objective in the management of endodontic treatment is eradication of bacteria, as well as elimination of endotoxin. The aim of this study was to compare the effectiveness of 5% sodium hypochlorite, a mixture of calcium hydroxide+2% chlorhexidine (CHX) gel and Nd:YAG lasers for decreasing the level of endotoxin in infected root canals. Material and Methods: Forty four patients in the age group of 18–50 years were carefully chosen for the study and divided into control (Group 1, n = 11) and experimental group (Group 2, n = 33). Experimental group was further split into three subgroups according to the medicaments used. Samples were collected after the access opening (pre-operative specimens), after the biomechanical preparation (intermediate samples), and after the application of intracanal medicament for 15 days. The concentration of endotoxin in each sample was measured using quantitative chromogenic limulus amebocyte lysate assay. The data collected were statistically analyzed using SPSS for Windows (Statistical Package for the Social Sciences, Inc., Chicago, IL,) Version 15.0 Statistical Analysis Software. The level of significance was set at 0.05 for all tests. Results: Pretreatment endotoxins level observed was 6.783EU/ml in Control group and 7.261EU/ml, 6.963EU/ml, 7.247EU/ml in experimental subgroups. After biomechanical preparation and use of medicaments endotoxins level reduced to 3.919EU/ml in Control group and 0.5222EU/ml (sodium hypochlorite) 1.164EU/ml (calcium hydroxide+chlorhexidine), 0.841EU/ml (laser). Conclusion: This study concluded after analyzing the data that use of 5% sodium hypochlorite and Nd:YAG laser was effective in decreasing the level of endotoxins and use of intracanal medicament (2% CHX+ calcium hydroxide) for 15 days further helps to reduce the endotoxin level.

Identification of Oil Palm’s Consistently Upregulated Genes during Early Infections of Ganoderma boninense via RNA-Seq Technology and Real-Time Quantitative PCR

Basal stem rot (BSR) disease caused by pathogenic fungus Ganoderma boninense is a significant concern in the oil palm industry. G. boninense infection in oil palm induces defense-related genes. To understand oil palm defense mechanisms in response to fungal invasion, we analyzed differentially expressed genes (DEGs) derived from RNA-sequencing (RNA-seq) transcriptomic libraries of oil palm roots infected with G. boninense. A total of 126 DEGs were detected from the transcriptomic libraries of G. boninense-infected root tissues at different infection stages. Functional annotation via pathway enrichment analyses revealed that the DEGs were involved in the defense response against the pathogen. The expression of the selected DEGs was further confirmed using real-time quantitative PCR (qPCR) on independent oil palm seedlings and mature palm samples. Seven putative defense-related DEGs consistently showed upregulation in seedlings and mature plants during G. boninense infection. These seven genes might potentially be developed as biomarkers for the early detection of BSR in oil palm.

Analysis of TCP Transcription Factors Revealed Potential Roles in Plant Growth and Fusarium Oxysporum F.Sp. Cubense Tolerance in Banana (cv. Rasthali)

The TCP transcription factor gene family is highly conserved among the plant species. It plays a major role in the regulation of flower symmetry, cell division, development of leaf, fibre and nodule in the plants by controlling the synthesis of various plant hormones. Banana is a major staple crop in the world. However, Fusarium oxysporum f. sp. cubense (Foc) infection is a major threat to banana production. The role of TCP gene family during the Foc infection is not explored till now. Herein, a total of 27 non-redundant TCP (MaTCP) gene sequences were retrieved from the banana genome and analysed for structural characteristics, phylogenetic correlation, subcellular, and chromosomal localizations. Phylogenetic analysis showed that the MaTCP proteins were highly conserved among different species and found to be the closest relative of the Oryza sativa and Zea mays. Promoter analysis of the TCP sequences showed that the cis-acting regulatory elements are associated with various stresses, environmental and hormonal signals. The higher transcripts accumulation in developing tissues (fruit finger, leaves, and stem) than of mature tissues (peel and pulp) showed a significant role of MaTCP in banana (cv. Rasthali) growth and development. Further, higher expression of the certain MaTCPs (MaTCP2, MaTCP4, MaTCP6, MaTCP9 and MaTCP11) in Foc race 1 infected root and leaf tissues of Rasthali indicated their promising role during Fusarium infection. This study will underpin the facet of TCP transcription factors on the development of biotic (Foc) stress tolerance in banana.

Digital Planning on Guided Endodontics Technology

The aim of this review is to discuss the digital planning and the use of guided technology in Endodontics. The complexity of the root canals anatomy and the challenges in the microorganism’s control represent risk factors for failure after the infected root canal’s treatment. Scientific improvements associated with technological advances have enabled better predictability of therapeutic procedures results. The development of efficient and modern devices provided safer root canal treatments, with shorter clinical visits and greater patient comfort. Digital endodontics incorporated different tools and developed its own, advancing even further in resolving complex cases. The faithful copy of the internal anatomy provided by the advancement of CBCT devices and software’s, associated with the digital resources of 3D planning and printing, enabled the advent of guided endodontics. This technique is used at different stages of endodontic treatment, with specific indications and greater result predictability. Therefore, this study critically reviewed the potential clinical application of this guided access technique, and the operative steps for its safe performance in managing complex endodontic cases. The main indications are accessing calcified root canals, performing endodontic surgeries in difficult access areas, removing fiberglass posts, and accessing teeth with developmental anomalies. In summary, guided endodontics has been a precise strategy, effective, safe, and clinically applicable. This procedure represents incorporating technological resources and digital planning in the Endodontist clinical practice, increasing predictability to complex cases.

Disease Incidence, Severity and Phenotypic Variation Among the Isolates of Rhizoctonia Bataticola Infected in Root Rot Disease of Mulberry in Different Mulberry Fields of Karnataka

The present investigation was carried out in view of destructive nature of root rot disease of mulberry caused by Rhizoctonia bataticola. The pathogen is a soil inhabiting fungus which is causing serious threat to more than 500 plant species. This study will enable to have a clear view of the root rot pathogen, R. bataticola in respect to variability, distribution and economic impact on mulberry plant. Root rot disease of mulberry is a devastating disease among the mulberry diseases. The part of study was conducted in Ramanagara district of Karnataka which is the largest market for silk cocoons in Asia, followed by Kanakapura in Karnataka, India. A field survey was conducted on disease incidence in various mulberry cultivating fields in Kanakapura and Ramanagara areas of Karnataka. Disease incidence of 78% and 53.60% with an average leaf yield loss of 39.73% covering 80 mulberry gardens has been reported in Kanakapura and Ramanagara respectively. From the infected root samples the phytopathogen, R. bataticola was isolated and its phenotypic variation was studied by growing the fungal pathogen on different fugal isolation media such as potato dextrose agar, richard’s agar and czapek dox agar under laboratory conditions. This study revealed the prevalence of the mulberry root rot disease in major mulberry growing locations in Karnataka. Incidence and severity of the mulberry root rot disease varied significantly among the locations under cropping seasons. This study was limited to southern Karnataka and did not cover other mulberry production locations in the different agro-ecological zones in Karnataka state. Therefore a study should be undertaken to evaluate the disease prevalence in other locations.

Antimicrobial Activity of Calcium Hydroxide Synthesized from Indonesian Limestone against Enterococcus faecalis

Recurrent endodontic infections of treated teeth are mainly linked to microbial persistency in the root canal system. Enterococcus faecalis is a bacterium that is often identified in these recurrent infections. Calcium hydroxide (Ca(OH)2) is a widely used root canal medicament and is now being developed to be produced from natural materials. Ca(OH)2, which is synthesized from natural limestone from Palimanan, Indonesia, has a structure similar to Ca(OH)2, which is often used as a root canal medicament. The purpose of this study was to determine the antimicrobial property of Ca(OH)2 paste synthesized from natural limestone compared to conventional Ca(OH)2 paste. This study is an in vitro experimental study consists of 3 groups (n=24, namely, conventional Ca(OH)2 paste, limestone synthesized Ca(OH)2 paste, and saline as the negative control, for 2 intervals of time and evaluated by Total Plate Counting (TPC) method. Samples were mandibular first premolar root canal prepared by root canal preparation and contaminated with E. faecalis (ATCC 29212). The infected root canals of each group were treated by the medicaments, and samples from the root canals were taken on day 7 (n=4) and 14 (n=4). Results showed that both Ca(OH)2 groups had antimicrobial activities against E. faecalis. The limestone Ca(OH)2 paste group had the least amount of bacterial colonies on the 7th day compared to other groups. In contrast, on the 14th day, the conventional Ca(OH)2 paste had the least bacterial colonies. It can be concluded that the Ca(OH)2 paste synthesized from natural limestone has an antimicrobial effect on E. faecalis, the antimicrobial effect was higher on the 7th day but decreases on the 14th day, whereas the conventional Ca(OH)2 had a higher antimicrobial effect on day 14 compared to day 7. Further studies are expected to improve the long-term antimicrobial effectiveness and sustainability of the natural limestone synthesized Ca(OH)2 paste.

Effect of the Passive Ultrasonic Irrigation and the Apical Diameter Size on the Debridement Efficacy of Infected Root Canals: A Multivariate Statistical Assessment of Histological Data

The removal of necrotic and vital pulp substrates and microorganisms and their toxins from the root canal system (RCS) has been found to be the basis for a successful endodontic treatment. In this study, our aim was to evaluate the effect of passive ultrasonic irrigation (PUI) on the elimination of the organic remnant tissue from infected, narrow and curved mandibular root canals during their instrumentation. For this purpose, mesiobuccal canals from mandibular first molars were instrumented with the RaCe rotary system, using PUI activation or conventional irrigation (CI) and two apical diameters (#25 and #35). The root canal cleanness of the samples was evaluated by microscopy and using a modified Langeland’s ordinal scale. Parametric and non-parametric statistical analyses and principal coordinates analysis (PCoA) of the samples were performed. When PUI was used, there was a significant reduction of the organic remnant in the apical enlargement of 25 at 2 mm from the apex (p < 0.001). After pooling the groups, regardless of the depth of the observation (2 and 4 mm from the apex), the pair #35 + PUI vs. #25 + CI showed statistically significant differences (p < 0.001). The effect of PUI explained 65% of the overall variance when compared with the CI samples. The use of PUI reduced the organic material of narrow infected and curved root canals with an apical enlargement of #25 and #35. When PUI is not used, a biomechanical instrumentation up to a diameter ≥#35 is recommended.

Photodynamic Inactivation of an Endodontic Bacteria Using Diode Laser and Indocyanine Green-Loaded Nanosphere

Apical periodontitis, an inflammatory lesion causing bone resorption around the apex of teeth, is treated by eradicating infectious bacteria from the root canal. However, it has a high recurrence rate and often requires retreatment. We investigated the bactericidal effect of antimicrobial photodynamic therapy (aPDT)/photodynamic antimicrobial chemotherapy (PACT) using indocyanine green (ICG)-loaded nanospheres coated with chitosan and a diode laser on a biofilm of Enterococcus faecalis, a pathogen of refractory apical periodontitis. Biofilm of E. faecalis was cultured in a porcine infected root canal model. ICG solution was injected into the root canal, which was then irradiated with a laser (810 nm wavelength) from outside the root canal. The bactericidal effect was evaluated by colony counts and scanning electron microscopy. The result of the colony counts showed a maximum 1.89 log reduction after irradiation at 2.1 W for 5 min. The temperature rise during aPDT/PACT was confirmed to be within a safe range. Furthermore, the light energy transmittance through the root was at a peak approximately 1 min after the start of irradiation, indicating that most of the ICG in the root canal was consumed. This study shows that aPDT/PACT can suppress E. faecalis in infected root canals with high efficiency.

Cymbopogon citratus essential oil: an active principle of nanoemulsion against Enterococcus faecalis root canal biofilm

Aim: The objective was to formulate and characterize the nanoemulsion based on Cymbopogon citratus oil, intended for use in teeth infected root canal therapy. The investigation of the antioxidant and antibiofilm potential toward Enterococcus faecalis was aimed as well. Materials & methods: Characterization of oil (by GC/MS analysis) and nanoemulsion (by dynamic light scattering instrument), and determination of antibacterial (by microdilution assay), antibiofilm (by crystal violet assay) and antioxidant properties (by 2,2-diphenyl-1-picryl-hydrazyl-hydrate and thiobarbituric acid assay methods) were provided. Antibiofilm efficacy of irrigation procedure including nanoemulsion was screened on extracted teeth (by CFU counting assay). Results: Notable antibacterial and antibiofilm activity, both against forming and preformed biofilms of oil, was observed. Irrigation involved nanoemulsion showed remarkable antibiofilm potential. Both substances induced some antioxidant activity. Conclusion: Results encourage further research with the aim of application of the nanoemulsion in dental practice.