Root Canal Disinfection Research Articles

Regenerative endodontic therapy in immature teeth using photobiomodulation and photodynamic therapy; a histomorphological study in canine model

BackgroundRegenerative endodontic therapy (RET) is still coming up short to demonstrate histological evidence for true regeneration with clinically feasible protocol of cell homing in single visit approach.AimThe aim of the present study is to evaluate the regenerative potential of photobiomodulation (PBM) on RET in immature roots when photodynamic therapy (PDT) protocol is implemented for root canal disinfection in canine model.Materials and methodsSeventy-two root canals were recruited, with sixty assigned to experimental groups and twelve to positive and negative controls. Following the induction of pulp necrosis and apical periodontitis, the roots were divided into two experimental groups: Group I received RET followed by PBM (seven sessions with an 808 nm diode laser at 300 mW for 90 s), and Group II received RET without PBM. Follow-ups were conducted at 1, 2, and 3 months (subgroups A, B, and C respectively). Qualitative and quantitative assessment was carried out histologically. All data were statistically analyzed with the Mann-Whitney U test and Bonferroni’s adjustment, as well as Chi square test.ResultsThe newly formed hard tissue highly resembled true dentine where the dentinal tubules looked well organized lined by poly layers palisading pattern of rounded odontoblast-like cells with cytoplasmic processes extending through the predentine layer. GI exhibited statistically significantly higher scores of vital tissue infiltration and hard tissue deposition in subgroups A and B (P ≤ 0.05). The inflammatory cells scores were significantly lower in GI than in GII at all time intervals. However, no significance could be detected regarding apical closure.ConclusionThe disinfection protocol of PDT and subsequent irradiation with low power laser in PBM protocol pose a promising potential for regenerative endodontics in immature teeth.

Evaluating the effectiveness of a novel training model in dental preclinical regenerative endodontic education.

Regenerative endodontic procedures (REPs) are tissue engineering-based treatments aimed at regenerating the pulp-dentin complex. However, these procedures are not widely practiced or well-known among dentists due to a lack of training. This study aims to develop a practical hands-on training model for REPs to enhance students' theoretical knowledge and practical skills. A cost-effective, easy-to-operate, and reusable training model for preclinical training of REPs was developed. A total of 125 undergraduates were divided into an experimental group (REPs model) and a control group (traditional teaching). The students' theoretical knowledge and operational skills were assessed through examinations and practical assessments. Student perceptions were assessed by questionnaires. The experimental group achieved higher scores in theoretical knowledge and operational skills compared to the control group (p < .001). The process evaluation of the experimental group demonstrated a high level of proficiency in executing root canal disinfection steps, with pass rates ranging from 93.5% to 95.2%. Students in both groups perceived the model as valuable for improving critical thinking, stimulating interest, and enhancing their confidence and proficiency. The developed REPs training model is a practical and effective tool for teaching and training regenerative endodontics. It bridges the gap between preclinical and clinical education, enhancing students' confidence and clinical competence.

A Novel pH-Responsive Nano-Sized Lanthanum-Doped Polyvinyl Alcohol-Carbon Quantum Dot Composite for Root Canal Irrigation.

The primary goals of endodontic therapy are to eliminate microbes and prevent reinfection. Persistent root canal infections and failure of root canal therapy are primarily attributed to the presence of bacteria, particularly E. faecalis. Chemical irrigants play a crucial role in complementing mechanical instrumentation in ensuring adequate disinfection. However, current techniques and available irrigants are limited in their ability to achieve optimal sterilization of the root canal system. In this study, we developed a novel material called La@PCDs by combining CQD-PVA and lanthanum for root canal irrigation. A one-pot hydrothermal method was used to prepare composites of lanthanum and CQD-PVA (La@PCDs). Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and the particle size were employed to characterize La@PCDs. ROS generation was evaluated by measuring the fluorescence intensity emitted at 525 nm from 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). In vitro experiments were conducted to assess the effectiveness of the nanoparticles in combating Enterococcus faecalis and eradicating in situ biofilm eradication in root canal. Furthermore, cytotoxicity assessments were carried out to demonstrate the safety of La@PCDs. SEM and FTIR results showed that La@PCDs were successfully prepared and exhibiting a homogeneous size distribution and irregular morphology. ROS assessment demonstrated that La@PCDs have a synergistic effect, promoting the production of a large number of ROS. This effect only occurred under acidic PH conditions. The inherent acidity in the biofilm microenvironment can act as internal stimulus. In vitro experiments revealed superior antibacterial efficiency under acidic conditions without causing significant cytotoxicity compared to the commonly used NaClO irrigant. The biosafety of La@PCDs was confirmed. Compared to existing materials, these nanoparticles exhibit favorable antibacterial and anti-biofilm properties, along with improved biocompatibility. These findings emphasize the potential of the integrated La@PCDs as a promising option for enhancing root canal irrigation and disinfection.

O USO DA OZONIOTERAPIA EM ENDODONTIA: UMA REVISÃO NARRATIVA DA LITERATURA

Introduction: Ozone, a powerful oxidizing agent, has antimicrobial, analgesic and anti-inflammatory properties, making it a promising alternative in dentistry, especially in endodontics. Objectives: This study aims to review the literature on the use of ozone therapy as an adjuvant therapy in the disinfection of root canals. Materials and Methods: A narrative review of scientific articles published between 2020 and 2024 was carried out, using databases such as PubMed, SciELO, LILACS and Google Scholar. Nine relevant articles focusing on the application of ozone in endodontics were selected. Discussion: Ozone has demonstrated efficacy in inactivating microorganisms without causing damage to human tissues, presenting itself as a viable option to sodium hypochlorite (NaOCl), which, although effective, has adverse effects. The use of ozone therapy can complement traditional methods, improving disinfection. Conclusion: Ozone therapy represents an effective and safe alternative for endodontic disinfection, but more studies are needed to establish standardized protocols and ensure their application in clinical practice.

A EFICÁCIA DA TERAPIA FOTODINÂMICA NO TRATAMENTO ENDODÔNTICO EM DENTES IMATUROS COM DIAGNÓSTICO DE NECROSE PULPAR: RELATO DE CASO CLÍNICO

Photodynamic Therapy (PDT) has been very effective in endodontics due to its benefits in eliminating resistant microorganisms in root canals. Being combined with a photosensitizing agent such as Methylene Blue, enhancing the effect of PDT, complementing conventional disinfection treatments, improving the effectiveness of endodontic treatment. The objective of this study was to report a clinical case on the use of photodynamic therapy in immature teeth with pulp necrosis, emphasizing the procedures performed, clinical and radiographic results obtained, as well as the effectiveness of different methods for disinfecting root canals. Research was carried out in electronic databases: Pubmed and Virtual Health Library from 2018 to 2024. The present work concluded that having knowledge about diagnosis and management in cases of immature teeth with pulp necrosis is extremely important to the dentist so that a good prognosis can be obtained in the treatment and so that the patient has the functionality of their oral environment reestablished.

Guided Endodontics in Calcified Canals: Literature Review

Endodontic treatment controls the root canal microbiota by shaping, disinfecting and filling the canals to promote periapical healing. The calcification process is linked to pulp alterations, usually caused by an inflammatory process due to caries, loss of tooth surface, trauma or pulp exposure. This study aimed to emphasize the influence of computed tomography-guided endodontics on the accuracy and efficacy of endodontic treatments compared to conventional techniques. Articles were selected from PubMed, SCIELO and BVS databases using the descriptors "endodontics OR root canal treatment AND dental calcification AND pulp cavity AND cone beam computed tomography". The study included articles published from 2013 to 2023. After analyzing the inclusion and exclusion criteria, 20 articles were selected. Endodontic treatment of calcified teeth is challenging and can result in failures in root canal instrumentation and disinfection. Also, it leads to complications such as perforation and weakening of the tooth structure due to excessive wear. Thus, minimally invasive endodontics is gaining prominence in contemporary endodontics. New techniques, such as guided endodontics, are emerging and have helped to reduce the risk of root perforation.

Comparative Assessment of the Antimicrobial Efficacy of Photoactivated Disinfection Employing Distinct Photosensitizers: A Morphological Analysis Using Scanning Electron Microscopy and Confocal Laser Scanning Microscopy.

Background The complex morphology of the root canal system and bacterial infiltration to greater depths precludes complete debridement by mechanical preparation alone. Despite promising characteristics of photodynamic inactivation (PDI) and different photosensitizers (PSs), there has been limited research on the antibacterial efficacy of chitosan (CS)-based PS combinations for root canal disinfection. We aimed to evaluate and compare the antimicrobial efficacy of photoactivated disinfection (PAD) using two different PSs as an adjunct to final irrigation in root canal treatment. Methodology Forty single-rooted human teeth were divided into four groups: Group A (positive control) = chemo-mechanical debridement (5.25% sodium hypochlorite(NaOCl)); Group B = chemo-mechanical debridement (5.25% NaOCl) + 15 μg/ml of methylene blue (MB) with T1 = 30 sec + diode laser (650 nm) and T2 = 30 sec; Group C = chemo-mechanical debridement (5.25% NaOCl) + 15 μg/ml of chlorin e6 (Ce6)with T1 = 30 sec + diode laser (650 nm) and T2 = 30 sec; Group D = chemo-mechanical debridement (5.25% NaOCl) + 15 μg/ml of Ce6 and CS with T1 = 30 sec + diode laser (650 nm) and T2 = 30 sec. Bacterial culture, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM) analysis were used to examine microbial coverage. The data were analyzed using IBM SPSS Statistics software, version 25 (IBM Corp., Armonk, NY); ANOVA followed by Tukey's post-hoc analysis was used to compare colony counts among the four groups. Results While inter-group comparison of pre-irrigation bacterial counts did not reveal a significant difference, post-irrigation counts were greater for NaOCl, followed by MB, Ce6, and Ce6+CS. However, all groups showed a significant reduction in counts post irrigation (Group A = 20.28 vs. 1.36; Group B = 20.12 vs. 1.11; Group C = 20.16 vs. .62; Group D = 20.20 vs. .33; all values in *10). Conclusion Based on colony counts and SEM and CLSM analysis, we found better anti-microbial properties for Ce6+CS, followed by Ce6, MB, and NaOCl, despite not having a difference in their colony counts before irrigation.

Synergistic bactericidal activity of chlorhexidine loaded on positively charged ionic liquid-protected silver nanoparticles as a root canal disinfectant against Enterococcus faecalis: An ex vivo study

The advancement of nanotechnology and the development of nanocomplexes offer promising solutions to address the limitations in biofilm management within endodontics. Current cleaning and disinfection methods often fail to completely eliminate bacterial biofilms from the complex anatomical structures of root canals, making the invention of new disinfectants or disinfection methods highly relevant. Previously, chlorhexidine-loaded positively charged ionic liquid-protected silver nanoparticles (CHX@AgNPs⁺) were introduced as an innovative root canal irrigation solution, demonstrating significant antibacterial efficacy against Enterococcus faecalis in vitro. This study aimed to further evaluate the antibiofilm activity of CHX@AgNPs⁺ in the root canals of extracted human teeth contaminated with E. faecalis biofilm. Fifty single-rooted human teeth with mature apices were randomly assigned to five experimental groups based on the irrigants used: CHX@AgNPs⁺, AgNPs⁺, 2.5 % NaOCl, 2 % CHX, and normal saline (n = 10 per group). The root canals were contaminated with E. faecalis, and biofilm formation was confirmed. Initial sampling (S1) was performed, followed by mechanical preparation of the root canals using ProTaper F3 files and irrigation with the respective test solutions. Post-instrumentation sampling (S2) was then conducted. The results demonstrated that CHX@AgNPs⁺ exhibited antibiofilm properties comparable to 2.5 % NaOCl, with no significant difference between them. Additionally, CHX@AgNPs⁺ significantly enhanced antimicrobial efficacy compared to CHX alone (P < 0.05), highlighting its potential as an effective root canal disinfectant.

Antimicrobial efficacy of nanoparticle calcium hydroxide and silver nanoparticles on Enterococcus faecalis: An in vitro study.

In root canal disinfection, intracanal medicaments play a vital role. Typical intracanal medicament, calcium hydroxide (CH), has the lowest efficacy against the biofilm of Enterococcus faecalis. Nanoparticles and their combinations may increase antimicrobial activity, making them better than conventional CH. The aim is to determine the efficacy of nanoparticle CH (NPCH) and silver nanoparticles (AgNP) against E. faecalis. A total of 60 premolars were chosen. The samples were cleaned and decoronated. Cleaning and shaping were done. The apices were tightly sealed with modeling wax before being injected with 5 μl of E. faecalis (ATCC 29212) bacterial suspension, and then left to incubate. Samples were categorized into CH (G-I), NPCH (G-II), AgNP (G-III), and a combination of NPCH + AgNP (G-IV) according to the intracanal medication used. Eppendorf tubes were used to transfer dentin chips after they had been incubated for 7 days. The process of obtaining bacterial colony-forming units (CFUs) involves inoculating sediments onto blood agar. The findings are statistically significant, number of CFUs seen with the Combination of NPCH + AgNP is lower than the other experimental groups, the group treated with CH had the largest number of CFUs. The highest antibacterial effect was seen in combination of NPCH + AgNP.

Quantitative analysis of antibacterial efficacy of herbal irrigants against endodontic microflora - A clinical study.

The study aimed to assess the antimicrobial effectiveness of green tea and neem extract compared to sodium hypochlorite (NaOCl) against various root canal microorganisms. Thirty patients with pulpal necrosis were selected, providing 60 samples before and after irrigation. Groups were assigned as follows: Group A: 3% NaOCl (control), Group B: green tea, and Group C: neem extract. Samples were collected before and after irrigation in two phases. Samples were collected maintaining a strict sterile condition and stored in buffer solution at -80°C for bacterial-load measurement through real-time Polymerase chain reaction (PCR). Statistical analysis included within-group comparisons using Wilcoxon's test and the paired t-test and inter-group comparisons using the Kruskal-Wallis test with post hoc Dunn's test and one-way analysis of variance with post hoc Tukey's honestly significant difference test (P ≤ 0.05). While no irrigant achieved complete bacterial eradication, all solutions exhibited significant antimicrobial activity postirrigation. NaOCl yielded the most effective results, with green tea nearly comparable, and neem extract demonstrating the lowest efficacy. Herbal irrigants, particularly green tea, can serve as effective alternatives to chemical solutions. However, neem extract proved less effective than both green tea and NaOCl, indicating its inferiority in root canal disinfection.

Clinical effectiveness of ultrasonic irrigation during root canal therapy: An umbrella review

ABSTRACT Aim: The aim of this study was to synthesize available knowledge on the efficiency of ultrasonic irrigation (UI) on the reduction of bacteria, postoperative pain reduction, and radiographic assessment of periapical healing during nonsurgical root canal treatments depicted by previous published systematic reviews (SRs). Methods: SRs with or without meta-analyses published in any language, assessing outcomes of UI on the reduction of bacteria, postoperative pain reduction, and radiographic assessment of periapical healing during nonsurgical root canal treatment were included. Two reviewers worked independently on study selection, data extraction, and appraisal of the included reviews. Disagreements were settled with the assistance of a third reviewer. Results: Seven SRs were included. The “Joanna Briggs Institute [JBI] critical appraisal tool” which consists of 11 items was used for evaluation of the quality of included SRs. Each JBI item was given a score of 1 if the criterion was met or 0 if the criterion was not met or the information was unclear. Conclusion: In clinical practice, UI provides similar outcomes in root canal disinfection and periapical healing compared to other irrigation methods and achieves better postoperative pain reduction and canal cleanliness when compared to syringe irrigation.

Testing the Inhibitory Activity of Bajakah Tampala (Spatholobus littoralis Hassk) Wood Extract from South Kalimantan on the Growth of Pseudomonas aeruginosa Bacteria

Background: Dental root canal treatment aims to eliminate microorganisms that cause infection in the tooth root canal, one of which is Pseudomonas aeruginosa bacteria. Disinfection of dental root canals with 0.5% - 5.25% NaOCl irrigation solution is still constrained so it is necessary to look for alternatives. The bajakah tampala plant (Spatholubus littoralis Hassk) is known to contain antibacterial compounds, namely flavonoids, saponins, tannins, and polyphenols. Objective: To evaluate the inhibitory activity of bajakah tampala wood extract (Spatholobus littoralis Hassk) from South Kalimantan against the growth of Pseudomonas aeruginosa bacteria. Method: Post test-only with control group design. The test groups were 100%, 75%, 50% bajakah tampala wood extract solution and positive control 2.5% NaOCL solution. Extraction using maceration method. Bacterial growth inhibition was tested by well diffusion method. Inhibition zone was measured using a caliper. Results: The growth inhibition from the largest to the smallest was shown by 75%, 100% and 50% bajakah wood extracts with mean inhibition zone diameters of 5.05 mm, 3.84 mm and 2.02 mm respectively, meanwhile the positive control was 16.14 mm. One Way Anova test showed significant difference in inhibition (p&lt;0.05) in all groups. Post hoc test showed no significant difference in the inhibition of 75% bajakah tampala wood extract with 100% extract. The inhibition of 100% and 75% extracts was significantly greater than 50% extract. The inhibition of NaOCL 2.5% was significantly greater than all groups of test extracts. Conclusion: Bajakah tampala wood extract has inhibitory activity against the growth of Pseudomonas aeruginosa bacteria.

Efficacy of Glycyrrhizin as an Intracanal Medicament on Bacterial Load Reduction in Primary Infected Root Canals: A Randomized Clinical Trial.

This study was done to clinically investigate the efficacy of glycyrrhizin-based intracanal medication (ICM) compared to calcium hydroxide Ca(OH)2 and Ledermix on the bacterial counts inside the root canals of necrotic teeth with chronic periapical periodontitis. Thirty-six patients having single-rooted and single-canaled necrotic teeth with chronic periapical periodontitis were enrolled in this research. Aseptic control measures were taken before clinical steps. Access cavity preparation was done. First bacteriological samples (S1) were collected immediately after access cavity preparation and before cleaning and shaping inside the root canals. Cleaning and shaping were performed on the root canals. Patients were randomly allocated into 3 groups according to the type of intracanal medicament used [Ca(OH)2, Ledermix, Glycyrrhizin]. Second bacteriological samples (S2) were collected after 1 week from placing the ICMs. S1 and S2 were transferred to the lab of microbiology for culturing on blood agar dishes in anaerobic conditions, and the bacteria on the plates were enumerated as colony-forming units (CFUs) by the manual counting method. The anti-bacterial efficacy of the ICM was estimated by the percentage reduction in the bacterial colonies from S1 to S2. All tested ICM documented a significant reduction in the CFUs from S1 to S2 (p < 0.05). Regarding S1, there was no significant difference between the three tested materials (p > 0.05). Regarding S2, Glycyrrhizin and Ledermix showed significantly lower CFUs than Ca(OH)2. There was no significant difference between Glycyrrhizin and Ledermix. Under the conditions of the present study, Glycyrrhizin and Ledermix showed comparable antimicrobial effects that were better than the commonly used Ca(OH)2 ICM. Glycyrrhizin may be a promising ICM. Herbal medicine can be considered as an alternative antimicrobial material for root canal disinfection because it has many benefits, like low toxicity, absence of microbial resistance, and favorable antimicrobial efficacy. This study highlights the clinical efficacy of Glycyrrhizin as a promising ICM. How to cite this article: Eltantawi AR, Abdel-Razik GM, Elhawary YM, et al. Efficacy of Glycyrrhizin as an Intracanal Medicament on Bacterial Load Reduction in Primary Infected Root Canals: A Randomized Clinical Trial. J Contemp Dent Pract 2024;25(6):540-546.

Evaluating the Impact of Modern Laser Technologies on Dentistry in European Union Countries

Introduction: In dentistry, understanding laser wavelength interactions with oral tissues enhances patient management. Over two decades, lasers have been used in dental practices for diagnostics, caries detection, calculus identification, hard tissue cutting, and root canal disinfection. They reduce patient anxiety and the need for anesthesia in hard tissue applications Aim. The objective of this research is to provide a review on how European dentistry has been affected by the use of modern laser technology between 2020 and 2024. This was done by classifying the types of lasers, examining their uses in different dental treatments, investigating the problems that may arise as a result, and appraising the benefits for oral health and patient outcomes. Methods: A systematic literature review was conducted from 2020 to 2024, focusing on modern laser technologies in dentistry within European countries. Using the PRISMA flow diagram, studies were identified, screened, and included based on keywords related to dentistry and laser technologies. Initial searches identified 17,130 records, narrowed down to 27 relevant studies through various criteria. Inclusion required studies to focus on dental laser applications in specified European countries, published between 2020 and 2024, and be peer-reviewed. Results: The review covered studies from 2020 to 2024, highlighting various dental specialties and laser technologies like Erbium, CO2, Diode, Nd, Excimer, and Fiber lasers. Findings indicated lasers improved precision, reduced discomfort, and enhanced patient outcomes with minimal postoperative pain and faster recovery times. Noted risks included thermal damage and specific complications like bleeding and pain. Conclusions: The review highlights lasers' transformative potential in EU dental care, offering precision and improved outcomes. Future research should standardize protocols, assess long-term benefits and risks, focus on safety, and integrate patient-centered outcomes to enhance the evidence base supporting laser technologies in routine dental care.

Evaluating the Impact of Ultrasonic Irrigation on Bacterial Levels and Activity Following Chemomechanical Procedures

IntroductionThis single-arm interventional trial aimed to investigate the efficacy of ultrasonic irrigation as a supplementary disinfection approach after chemomechanical procedures (CMP) using molecular techniques based on ribosomal RNA (rRNA) and rRNA genes (referred to as DNA). MethodsSamples were collected from 35 single-rooted teeth with radiographic evidence of apical periodontitis. Samples were taken after gaining root canal access (S1), (S2), and ultrasonic irrigation (S3). DNA-targeted quantitative polymerase chain reaction using universal primers was used to estimate total bacterial levels, while rRNA-targeted quantitative polymerase chain reaction was used to assess bacterial activity. Ratios between rRNA and DNA levels were calculated to search for active bacteria in the samples (rRNA/DNA ≥ 1). Wilcoxon matched-pairs signed-rank test was used to compare the differences in DNA levels between samples and DNA and rRNA levels within samples (P < .05). ResultsDNA-based methods revealed a significant decrease in bacterial levels from S1 to S2 and S2 to S3 (both P < .05). Notably, 11 out of 35 (31.4%) root canals did not harbor bacterial DNA after CMP, whereas ultrasonic activation increased DNA-negative samples to 17 (48.6%). However, all DNA-positive samples were also positive for rRNA, with significantly higher rRNA than DNA levels (P < .05), indicating bacterial activity at the sampling time. ConclusionsUltrasonic irrigation improved the disinfection of root canals after CMP by reducing bacterial levels. However, persisting bacteria remained active in the root canals after CMP and ultrasonic irrigation.

Effectiveness of LED-curing light photodynamic therapy with curcumin (cur-aPDT) as a disinfection method in root canal

Background: Root canal treatment (RCT) is an endodontic treatment that reduces microbial growth and provides a suitable environment to induce periradicular healing. The prevalence of root canal treatment failure caused by Enterococcus faecalis bacteria reaches 90% because the bacteria form biofilms to defend themselves against antibacterial agents. Although the conventional use of NaOCl as a disinfectant has been well-known for a long time, improved disinfection methods are needed to optimize root canal treatment. One of the treatments that can provide better results through reducing the number of microbes is photodynamic therapy (aPDT) mediated with curcumin compound (Cur- aPDT) as a photosensitizer. Curcumin is a compound that can be used as a root canal disinfecting agent which can increase dentin bond strength through its antimicrobial and antioxidant activities with its natural pigment as a photosensitizer. Materials and Methods: The literature review was carried out on PUBMED, MDPI, and Sciencedirect databases with a limit of 2019-2024 to identify published research on the antimicrobial effectiveness of Cur-aPDT as a root canal disinfection method. Conclusion: This review shows that Cur-aPDT is an effective method to disinfect root canals.

Preparation, structure, osteogenic differentiation ability, and biosafety of bioglass for root canal disinfection

In this paper, SiO2-P2O5-Ca(Sr/Zn)O-Na2O-F system glasses with varying CaO:SrO and CaO:ZnO ratios were prepared by traditional melting method, which combined the remineralization properties of bioglass with the special functions of Zn2+ and Sr2+. The evolution of glass composition and its thermal properties, network structure, and biological properties was investigated by DSC, FTIR, and biological experiment. The results showed that all the extracts of glass powder could promote the osteogenic differentiation of human periodontal ligament cells (HPDLCs). Among them, the two kinds of glass containing 6 wt% SrO and only 2 wt% ZnO had the greatest potential to accelerate the bone tissue reconstruction. Hematoxylin-eosin (HE) staining histological results showed that 3 months after the two kinds of glass were implanted in the animal model of periapical inflammation, the bone matrix formed a good seal in the apical foramen, and new bone and capillaries were formed in the apical area, which has a clinical application and transformation prospect.

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

AimImpact 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 methodSingle 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. ResultGroup 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. CONCLUSIONCNPs-RBP activated by DL as the final irrigant provided satisfactory antibacterial activity, SL removal, and bond strength outcomes compared to other tested groups.

New Insights Regarding the Use of Relevant Synthetic Compounds in Dentistry.

Worldwide, synthetic compounds are used for both in-office and at-home dental care. They are a valuable resource for both prophylactic and curative treatments for various dental problems, such as tooth decay, periodontal diseases, and many more. They are typically preferred due to their broad range of actions and ability to produce targeted, rapid, and long-lasting effects. Using a 0.12% chlorhexidine mouthwash is capable of reducing the plaque index from 47.69% to 2.37% and the bleeding index from 32.93% to 6.28% after just 2 weeks. Mouthwash with 0.1% OCT is also highly effective, as it significantly lowered the median plaque index and salivary bacterial counts in 152 patients in 5 days compared to a control group (p < 0.0001), while also reducing the gingival index (p < 0.001). When povidone-iodine was used as an irrigant during the surgical removal of mandibular third molars in 105 patients, it resulted in notably lower pain scores after 2 days compared to a control group (4.57 ± 0.60 vs. 5.71 ± 0.45). Sodium hypochlorite is excellent for root canal disinfection, as irrigating with 1% NaOCl completely eliminated the bacteria from canals in 65% patients. A 0.05% CPC mouthwash proved effective for perioperative patient care, significantly decreasing gingival bleeding (p < 0.001) and suppressing Streptococcus levels even one week post-surgery. Lastly, a 6% H2O2 paint-on varnish and 6% H2O2 tray formulations successfully bleached the teeth of 40 patients, maintaining a noticeably whiter appearance up to the 6-month follow-up, with significant color differences from the baseline (p < 0.005). Synthetic compounds have a large research base, which also provides a greater awareness of their mechanism of action and potential adverse effects. For a better understanding of how they work, several methods and assays are performed. These are protocolary techniques through which a compound's efficacy and toxicity are established.

Effects of the Irrigation Needle Design on Root Canal Disinfection and Cleaning

IntroductionThis ex vivo study evaluated the disinfecting and cleaning effects of root canal preparation using sodium hypochlorite irrigation with 3 different needle designs. MethodsMesial roots from extracted mandibular molars with Vertucci class II configuration were anatomically matched based on micro-computed tomography (micro-CT) analyses and distributed into 3 groups (n = 18/group). The canals were contaminated with a mixed bacterial culture for 30 days and then subjected to preparation using 2.5% sodium hypochlorite irrigation with open-ended flat needle (3 mm short of the working length - WL), closed-ended side-vented irrigation needle (1 mm short of the WL), or a closed-ended plastic needle with 2 lateral outlets (TruNatomy) (1 mm short of the WL). Bacteriological samples were taken from the canals before (S1) and after preparation (S2). After another micro-CT scan, the roots were sectioned and samples were also taken from the apical canal segment (S3). Bacterial reduction was assessed by quantitative real-time polymerase chain reaction. The amount of accumulated hard tissue debris was evaluated by micro-CT. ResultsA substantial reduction in bacterial counts was observed in all 3 groups when comparing S1 with S2 (99.95%, 98.93%, and 98.90% in the open-ended, closed-ended, and TruNatomy needle groups, respectively) (P < .01). No significant differences were observed between groups for bacterial reduction in the full and apical canal (P > .05). There were no intergroup differences in the amount of accumulated hard tissue debris either (P > .05). The open-ended needle group showed significantly more specimens with quantitative real-time polymerase chain reaction negative results for bacteria in S3 than TruNatomy (P < .05). ConclusionWhen used up to an appropriate insertion depth, the 3 needle types result in similar antibacterial and cleaning performance, provided variables such as needle size and irrigant type, volume and flow rate are controlled. Exclusive analysis of the apical segment, including the isthmus, revealed that the open-ended needle yielded more cases negative for bacteria.