Optimizing vancomycin therapeutic drug monitoring compliance in pediatric oncology: towards personalized medication management.

Aim: Vancomycin, a crucial treatment for Gram-positive bacteria, necessitates therapeutic drug monitoring (TDM) to prevent treatment failures. We investigated the healthcare professional's compliance toward TDM of vancomycin recommendations and follow-up levels. Materials & methods: We collected data from 485 patients who received vancomycin in the Children's Cancer Hospital Egypt 57357 medical records system (Cerner) over 4 months, from January to April 2020. Results: Our data shows that only 54% of patients had TDM requests from healthcare professionals for the total patients who received vancomycin treatment. The healthcare professionals' compliance with the recommendations was 91.7%, while the follow-up levels were 66.7%. Conclusion: While overall adherence to recommendations is strong, enhancing compliance with follow-up levels remains a priority for improvement.

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Clinical Pharmacogenetics Implementation Consortium Guideline (CPIC) for CYP2D6, ADRB1, ADRB2, ADRA2C, GRK4, and GRK5 Genotypes and Beta-Blocker Therapy.

Beta-blockers are widely used medications for a variety of indications, including heart failure, myocardial infarction, cardiac arrhythmias, and hypertension. Genetic variability in pharmacokinetic (e.g., CYP2D6) and pharmacodynamic (e.g., ADRB1, ADRB2, ADRA2C, GRK4, GRK5) genes have been studied in relation to beta-blocker exposure and response. We searched and summarized the strength of the evidence linking beta-blocker exposure and response with the six genes listed above. The level of evidence was high for associations between CYP2D6 genetic variation and both metoprolol exposure and heart rate response. Evidence indicates that CYP2D6 poor metabolizers experience clinically significant greater exposure and lower heart rate in response to metoprolol compared with those who are not poor metabolizers. Therefore, we provide therapeutic recommendations regarding genetically predicted CYP2D6 metabolizer status and metoprolol therapy. However, there was insufficient evidence to make therapeutic recommendations for CYP2D6 and other beta-blockers or for any beta-blocker and the other five genes evaluated (updates at www.cpicpgx.org).

De novo regeneration of dentin pulp complex mediated by Adipose derived stem cells in an immunodeficient albino rat model (Histological, histochemical and scanning electron microscopic Study).

Background: Dental tissue engineering is an alternative procedure for restoring damaged dental tissues. Adipose-derived stem cells are a new source of cells for regenerative endodontics in combination with scaffold materials. The descriptive data about this regenerative process is still insufficient. Objective: To evaluate the regenerative potential of Adipose-derived stem cells using a self-assembling polypeptide scaffold for the dentin-pulp complex in an emptied root canal space. Material and Methods: 40 root segments of human single-rooted teeth were transplanted into the albino rats' dorsal subcutaneous tissue. Root segments were divided into two groups: group I contained only a self-assembling polypeptide scaffold, and group II contained fluorescent-labeled Adipose-derived stem cells embedded in a self-assembling polypeptide scaffold. The newly formed tissues were assessed on the 60th and 90th days post-transplantation using routine histological examination, Masson trichrome staining, and scanning electron microscopy. Results: Group I showed granulation tissue without any signs of predentin formation or odontoblast-like cells. Group II revealed the presence of predentin tissue along the dentin margin, with arranged odontoblast-like cells. An organized connective tissue with abundant vasculature and calcific masses was observed in the pulp space. Conclusion: Adipose-derived stem cells can be considered as alternative stem cells for regenerating the dentin-pulp complex. Dentin pulp complex regeneration utilizing a self-assembling polypeptide scaffold alone would not yield successful results.

Virtual Fracture Clinic Patients' Satisfaction Outcomes.

Background During the COVID-19 pandemic, there was a need to balance optimum treatment service and the safety of patients and hospital staff. The British Orthopaedic Association recommended a virtual fracture clinic to give the right first-time decision and to minimize patient exposure to disease. This study aimed to evaluate the patients' satisfaction outcomes for the service provided through the virtual fracture clinic. Methodology From January to May 2022, all patients seen by the staff in the Emergency Department (ED) at Queens Burton Hospitals were enrolled in a prospective study. An Excel spreadsheet was provided to both ED personnel and the orthopaedic team for accessibility. Patients were continually added to the spreadsheet, and their cases were reviewed by the on-call consultant to devise treatment plans. A satisfaction questionnaire was collected from patients about their virtual clinic experience as a route to provide treatment service. Results The study comprised 150 patients, with an average age of 40 years. Distal radial fractures represented one-third of the cases. Different modalities of management were offered such as a sling, splint, cast, or referral to physiotherapy. Around 75% of cases were satisfied, understood the advice given over the phone, and were not required to attend the actual clinic. The remaining quarter attended the clinic either for further reassessment by an orthopaedic surgeon or for discussion of their injury as they could not get the full message over the phone due to fast calls, hearing struggles, or just listening to messages. Conclusions The virtual fracture clinic is an effective standalone service that gained around 75% satisfaction in patients' outcome questionnaires. It saved the actual fracture clinic slots and hospital resources. It is recommended to be part of the standard daily practice throughout the United Kingdom.

Efficacy and Toxicity of Vincristine and CYP3A5 Genetic Polymorphism in Rhabdomyosarcoma Pediatric Egyptian Patients.

BACKGROUND: Rhabdomyosarcoma (RMS) is a rare cancer that develops in soft tissue, particularly skeletal muscle tissue and occasionally hollow organs like the bladder or uterus. Vincristine (VCR) is the main therapy used in treatment of RMS, it is an alkaloid produced from vinca and it is one of the most commonly prescribed drugs in pediatric oncology for the treatment of a number of tumors. The CYP3A5 enzyme is responsible for vincristine metabolism. The effect of CYP3A5 genetic polymorphism on the efficacy and toxicity of VCR on RMS patients still needs further research. METHODS: Genotyping for CYP3A5 SNPs rs776746, rs10264272 and rs41303343 was performed using Taqman Real-Time PCR assays in a retrospective cohort study of 150 RMS pediatric patients treated with vincristine. The relationship between these genotypes and RMS survival was then examined. RESULTS: We found that patients with CYP3A5*3/*3 had the highest incidence of vincristine-induced neuropathy reaching 61.3%. Patients with CYP3A5*1/*3, CYP3A5*3/*6 and the normal metabolizers with CYP3A5*1/*1 had frequencies of 22%, 10.7%, and 4.7%. patients with the lowest frequency of 1.3% were those with the CYP3A5*1/*6 genotype. There was no correlation between the genotypes of CYP3A5*3, CYP3A5*6, CYP3A5*7, and RMS survival. Initial risk, metastasis, response, convulsions, unsteady gait and hepatotoxicity grade had a significant effect on overall survival with p<0.05. CONCLUSION: CYP3A5*1/*1 have less severe vincristine-induced neuropathy than CYP3A5 *1/*3, CYP3A5 *1/*6 and CYP3A5 *3/*3, CYP3A5 *3/*6. There is a significant influence of CYP3A5 mutation on neuropathy grade and assist of ADL as a part of neurotoxicity.

Structural aortic wall abnormalities following the Nikaidoh operation, which could be reversible and include a healing process.

The Nikaidoh operation continues to be used for patients with transposition of the great arteries, ventricular septal defect and left ventricular outflow tract obstruction. We recently reported structural and functional changes in the aortic root during the follow-up of a patient who underwent the Nikaidoh operation. These changes necessitated re-operation. The pathophysiology of these changes and their potential for reversibility have not yet been studied. In this communication, we describe the extensive structural changes in the aortic wall of the same patient.

Valvulogenesis of a living, innervated pulmonary root induced by an acellular scaffold.

Heart valve disease is a major cause of mortality and morbidity worldwide with no effective medical therapy and no ideal valve substitute emulating the extremely sophisticated functions of a living heart valve. These functions influence survival and quality of life. This has stimulated extensive attempts at tissue engineering "living" heart valves. These attempts utilised combinations of allogeneic/ autologous cells and biological scaffolds with practical, regulatory, and ethical issues. In situ regeneration depends on scaffolds that attract, house and instruct cells and promote connective tissue formation. We describe a surgical, tissue-engineered, anatomically precise, novel off-the-shelf, acellular, synthetic scaffold inducing a rapid process of morphogenesis involving relevant cell types, extracellular matrix, regulatory elements including nerves and humoral components. This process relies on specific material characteristics, design and "morphodynamism".

Outcomes Following Type C Distal Humeral Fracture Fixation Using Two Different Osteosynthesis Techniques.

BACKGROUND: Distal humeral fractures are notorious injuries, and they require surgical fixation. The reliability of reconstruction devices has been a subject of debate. Our primary outcome was to detect differences, if any, between two different groups of patients using the patient-reported outcomes measurement information system (PROMIS) Global-10 form and to compare it with the Mayo elbow performance score (MEPS) results. Other secondary outcomes included the difference in union time between patients who received a reconstruction plate vs those who received a pre-contoured anatomical plate. MATERIAL AND METHODS: It is a prospective randomised study which included a total of 30 cases equally distributed into two groups. RESULTS: The mean PROMIS and MEPS scores for group A were 31.5 SD 6.6 and 77.7, respectively, compared to 33.7 SD 6.66 and 73, respectively, for the other group. Time to union was 13.4 weeks for group A and 12.6 weeks for the other group. There was no statistically significant difference between the groups regarding union and function. However, reconstruction plates were more cost effective. The correlation between the MEPS and PROMIS G scores in both groups was statistically significant. CONCLUSION: 1. Recon plates continue to be a cost-effective method of treatment in simple intra-articular fractures. 2.PROMIS is a valuable tool to be used along with other scores in future studies.

Management of chronic myeloid leukaemia: current treatment options, challenges, and future strategies.

ABSTRACTSmall molecule therapy is a critical component of targeted anticancer treatment, with tyrosine kinase inhibitors (TKIs) being the first compounds to treat the clonal Chronic Myelogenous Leukaemia (CML) translocation t (9;22) (q34; q11) effectively since 2001. TKIs, such as imatinib, have improved the 10-year survival rate of CML patients to 80%. They bind the BCR::ABL1 kinase and inhibit downstream signaling pathways. However, therapy failure may be seen in 20-25% of CML patients due to intolerance or inadequacy related to BCR::ABL1 dependent or independent mechanisms. This review aimed to summarize current treatment options involving TKIs, resistance mechanisms and the prospective approaches to overcome TKI resistance. We highlight BCR::ABL1-dependent mechanisms of TKI resistance by reviewing clinically-documented BCR::ABL1 mutations and their consequences for TKI binding. In addition, we summarize BCR::ABL1 independent pathways, including the relevance of drug efflux, dysregulation of microRNA, and the involvement of alternative signaling pathways. We also discuss future approaches, such as gene-editing techniques in the context of CML, as potential therapeutic strategies.

Physiotherapy-Led Musculoskeletal Telephone Triage and Advice Service: A Valid Option for Patients Referred From the Emergency Department.

Introduction Musculoskeletal (MSK) conditions create a significant demand for healthcare services in the United Kingdom. The emergency department is one of the main providers of initial care for patients with MSK disorders or injuries. As attendances increase within the emergency department the demand for MSK physiotherapy services also increases. The MSK physiotherapy department at Queens Hospital, Burton, GBR introduced a telephone triage and advice (TTAD) service for patients referred from the emergency department to try and reduce waiting times and the number of initial appointments not attended. The primary outcome of the study was to investigate the number of patients discharged via the TTAD service. Secondly, the study aimed to assess if the TTAD service eased the pressures of face-to-face appointments as well as analyze the effects on the number of failed attendances and canceled appointments for both initial and follow-up face-to-face appointments. Method Data were collected retrospectively from the electronic medical records system Meditech Version 6 (Medical Information Technology, Inc., MA) from the months of August, September, and October in 2017 (pre-TTAD) and 2018 (post-TTAD). Once the data had been collected, analysis was performed comparing results from 2017 to 2018 using Statistical Product and Service Solutions (SPSS) (IBM SPSS Statistics for Windows, Armonk, NY) analysis software. Results The overall number of referrals from emergency to MSK physiotherapy increased by 11.2% between 2017 and 2018. Following the introduction of the TTAD service, 59.8% of the total referrals were offered a face-to-face initial appointment with 40.2% of patients referred being discharged via the TTAD service in 2018. The percentage of patients that failed to attend the initial appointment in 2018 also fell by 4.9%. Conclusion The introduction of a TTAD service for referrals from the emergency department has been demonstrated to be effective in reducing the number of face-to-face appointments required in the MSK physiotherapy management of these patients. Both initial and follow-up face-to-face appointments were lower in 2018 when compared to 2017, this is despite an 11.2% increase in the number of referrals throughout August, September, and October. It can therefore be concluded that the TTAD service also had a positive impact on the failed attendance rate of initial face-to-face appointments.

Comparison between platelet-rich plasma (PRP) and mechanically emulsified fat grafts in management of chronic wounds.

BACKGROUND: chronic wounds represent a challenge in treatment, due to diverse pathogenesis, resistance to ordinary treatment complex and lack of direct methods of treatment In this study, the aim is to compare the effect of Platelet -rich plasma (PRP) and mechanically emulsified fat grafts on the outcome of the healing process of chronic wounds. PATIENTS AND METHODS: In the current study, 30 patients with chronic wounds were divided into two groups (Group I, 15 patients had application of PRP on chronic wounds). Whereas (Group II, 15 patients had application of mechanically emulsified fat on chronic wounds). In both groups assessment of the healing rates and histopathological changes that were determined by observing the parameters of wound healing, including peri-lesional skin quality, observation of the wound size and depth, assessment of the pain indicated by Visual analog scale score. RESULTS: Patient were followed up for 6 months. Group II showed a better healing rate 64% in comparison to Group I 55%. Wound parameters and pain score were recorded in both groups with no statistically significant difference. CONCLUSION: Both PRP and mechanically emulsified fat grafts were found to be efficient treatment modalities in management of chronic "non-healing" wounds. But mechanically emulsified fat grafts represent a better treatment method for chronic wounds.

Healthcare workers' mental health and perception towards vaccination during COVID-19 pandemic in a Pediatric Cancer Hospital.

The consistent increase of Coronavirus disease 2019 (COVID-19) cases parallel with the rate of deaths and the controversial response regarding the vaccines caused an increase in the burden of psychological diseases. This study aimed to evaluate the psychological condition of healthcare workers (HCWs) in a pediatric cancer hospital and to identify the knowledge, attitude, and perception (KAP) of HCWs toward COVID-19 vaccination. A cross-sectional observational study was conducted between April to May 2021. A validated, confidential survey was employed to measure the mental health of HCWs and the KAP toward COVID-19 vaccines. The total responses were 395, of which 11.4% physicians, 18.5% pharmacists, and 70.1% were nurses. Sixty-six percent of HCWs had different degrees of anxiety and depression. Nurses significantly accounted for the highest anxiety levels (P = 0.003), while the cumulative anxiety score was significantly higher in HCWs who had a positive history of COVID-19 infection (P = 0.026). Although 67.6% of HCWs believe that "vaccines are essential for us,", the vaccination rate was 21.3%. The Factors associated with not receiving the vaccine were younger ages (P = 0.014), nurses (P = 3.6987 × 10-7), negative history of COVID-19 infection (P = 0.043) and believing that infections can happen after taking the vaccine (P = 1.5833 × 10-7). Healthcare organizations must take serious intervention to decrease the mental load on HCWs and facilitate the vaccination process.

Three-Dimensional tooth models for better teaching and treatment outcomes.

INTRODUCTION: The aim of this study was to fabricate 3-Dimensional (3D) tooth models to overcome procedural errors that occur during treatment and to improve endodontic management of teeth with complex pulp morphology and dental anomalies. MATERIALS AND METHODS: Three natural teeth were used to fabricate resinous tooth models (n = 90) and 90 natural teeth were used during root canal treatment. Models were fabricated from 1 mandibular canine (n = 30) and 2 maxillary molars (n = 60). Natural teeth were 30 mandibular canines, 30 mandibular molars and 30 maxillary molars. RESULTS: Natural teeth and opaque resin models were significantly better than the clear resin models during access preparation (p = .003). In addition, the clear resin models were significantly better than the natural teeth and opaque resin models during shaping, obturation and as an educational tool (p < .001, p < .001 and p < .001 respectively). CONCLUSIONS: Although it takes more time and effort to produce 3D (3D) tooth models from each natural tooth used in the study, it can give more accurate results during evaluation.

Results of Wedgeless Distal Femoral Osteotomy for the Treatment of Genu Valgus Deformity.

INTRODUCTION: Coronal plane knee deformities are common disorders affecting adolescents. Valgus deformities (tibiofemoral angle (TFA) > 12-15 degrees and intermalleolar distance (IMD) > 10 cm) often require corrective osteotomy and a wedgeless "V" distal femoral osteotomy is a good treatment option for such deformities. MATERIALS AND METHODS: Thirty adolescent patients (13-17 years) with valgus deformities were included. Patients with severe collateral ligament instability, subluxation, and sagittal plane deformity > 15 degrees or genu valgum due to tibial deformity were excluded. Preoperative clinical (Bostman's knee score, IMD, and knee-flexion test) and radiological evaluations were done. The surgery (wedgeless distal femoral V osteotomy) was performed and stabilized with two Kirschner wires (K-wires). Postoperative clinical and radiological parameters were recorded including complications. RESULTS: The preoperative TFA was 20.23 ± 3.63 degrees, which reduced to 5.5 ± 0.73 at six months postoperatively. The preoperative IMD was 12.45 ± 2.2 cm, which reduced to 1.63 ± 0.32 cm at six months. The mean mechanical axis deviation (MAD) and lateral distal femoral angle (LDFA) were recorded as 2.8 ± 0.39 and 87.7 ± 0.83, respectively, and the differences were statistically significant from preoperative values. The Bostman score was 26.2 ± 1.79 at three months and 29.47 ± 0.9 at six months. The complications included infection in two patients, a hypertrophic scar in one patient, and common peroneal neuropraxia in one patient. CONCLUSION: Wedgeless distal femoral osteotomy with K-wire fixation is a viable option for correction of genu valgus deformity with potential advantages of minimal blood loss, no leg length discrepancy, non-rigid fixation, and early union as compared to other treatment options.

Knowledge, attitudes and practice regarding pharmacovigilance and adverse drug reaction reporting among physicians and pharmacists in Egypt: a step toward personalized medicine implementation.

Aim: To assess the knowledge, attitudes, and practices of the healthcare professionals working at Children's Cancer Hospital Egypt regarding pharmacovigilance (PV) and adverse drug reaction (ADR) reporting, in addition to the ADR reporting barriers. Materials & methods: A cross-sectional study was conducted at Children's Cancer Hospital Egypt from July to September 2021 using a validated questionnaire. Results: About 37 physicians (20.3%) and 145 pharmacists (79.7%) responded to the survey. Overall, the knowledge (median: 40%) and practice (median: 50%) of PV and the reporting of ADRs were low; however, attitudes were mostly positive. The main barrier to reporting ADRs was The difficulty of determining whether or not ADRs occurred (42.3%). Conclusion: Understanding of PV and ADR reporting could improve the huge gap between ADRs experienced and ADRs reported. In order to be able to assess the impact of personalized medicine implementation, adequate ADR reporting should be well established.

Since no medication is completely safe, many of them are associated with multiple adverse reactions that may affect patients' health in terms of morbidity and, even worse, mortality. These concerns greatly increase the importance of reporting adverse drug reactions (ADRs), which highlights the essential role of pharmacovigilance (PV) centers. This study was performed at Children's Cancer Hospital using a validated questionnaire; to collect information on healthcare professionals' demographics and their knowledge of, attitudes toward and practices in PV; analyze reasons for the the under-reporting of ADRs; and recommend possible ways to improve reporting. The majority of the healthcare professionals had poor knowledge and practice of PV and ADR reporting, which clearly explains the huge gap between ADRs experienced and ADRs reported. However, they have a positive attitude toward PV and ADR reporting.

The Use of Fluoroscan in Hand Clinic During the Covid Pandemic to Optimise Conservative Treatment.

Introduction The study assessed the use of Fluoroscan (Hologic, Inc., Marlborough, MA) in hand clinic as advised by the British Orthopaedic Association (BOA) during the COVID-19 pandemic to facilitate treatment of fractures requiring manipulation and reduce admissions to evaluate if this should be embedded in practice permanently. Method Eighty-three wrist and hand fractures requiring manipulation were identified between April 2020 and March 2021. Demographics, mechanism of injury, timing of intervention, radiological outcome, further intervention and functional assessment by QuickDASH scoring were recorded. Results Sixty-eight cases were manipulated within the first week of fracture, simple pain control measures were used, and dose area product (DAP) averaged 1.3 Gy cm2 well below the dose limit set by the trust. Satisfactory fracture reduction was achieved in 59 cases avoiding admission. Further surgical intervention was offered to 24 patients: five re-manipulated while 19 had operation, all with a good functional outcome. Conclusion Fluoroscan use in fracture clinics achieved effective fracture control in 77% of cases. The use of Fluoroscan avoided admissions for surgery during the pandemic and lengthy clinic visits, four out of five did not need admission.

Knowledge, attitudes and practices of Egyptian healthcare professionals toward therapeutic drug monitoring service as a principal component of personalized medicine.

Aim: To assess pharmacists' and physicians' knowledge, attitudes and practices toward therapeutic drug monitoring (TDM) service at the Children's Cancer Hospital Egypt 57357. Materials & methods: This was a single-site cross-sectional study where all practicing pharmacists and physicians were eligible to participate. Results: A statistically significant difference in the knowledge scores between pharmacists and physicians (p = 0.022) was found. In general, attitudes toward TDM among pharmacists and physicians were positive. Regarding practices, pharmacists were more likely than physicians to agree or strongly agree that they have studied some scientific references on TDM (p = 0.034), but more physicians recommend the TDM service (p = 0.046). Conclusion: A multidisciplinary educational program in Egypt for TDM for both medicine and pharmacy staff will improve interprofessional collaboration in the clinical setting, leading to better personalized medication management.

The objective of the present survey was to evaluate the knowledge, attitudes and practices of pharmacists and physicians toward therapeutic drug monitoring (TDM) services at the Children's Cancer Hospital Egypt 57357. TDM is defined as 'measuring the amount of specific drugs in patients' blood to ensure that the concentrations of administered drugs are both effective and safe'. A single-centered study was conducted at the CCHE where all pharmacists and physicians participated. There was a remarkable difference in the knowledge scores between pharmacists and physicians. Generally, both pharmacists and physicians demonstrated positive attitudes toward TDM. In real-life practice, pharmacists were more likely than physicians to agree that they had scientific evidence about TDM. Multidisciplinary educational programs for TDM among physicians and pharmacists would improve interprofessional collaboration for the benefit of patients in Egypt.

Inflammatory response and immunohistochemical characterization of experimental calcium silicate-based perforation repair material.

This study compares the immunohistochemical reaction of a new experimental tricalcium silicate perforation repair material to mineral trioxide aggregate (MTA) and Biodentine. A total of 162 mature premolar teeth from 12 dogs were divided into three experimental groups (n = 54 teeth each) according to the evaluation period: 1, 2 and 3 months. Each group was further divided into two equal subgroups (n = 27 teeth each) according to the time of repair: immediate repair and delayed repair. Each subgroup was subdivided according to the material used into three experimental subdivisions (n = 8 teeth each): MTA, Biodentine (Septodont) and experimental material, and two control subdivisions: positive control (n = 2 teeth) and negative control (one tooth). Under general anaesthesia, access cavity was done. Cleaning and shaping were performed using ProTaper universal rotary instruments. The canals were obturated using cold lateral compaction technique with Gutta percha and Adseal sealer. Furcation perforations were created then randomly sealed using the three materials either immediately or after one month (delayed repair). Inflammatory cell count and immunohistochemical analysis of osteopontin-positive area fraction were digitally analysed using the ImageJ software. Delayed furcal perforation repair showed significantly higher inflammatory cell count than immediate repair. No significant difference in inflammatory cell count and immunohistochemical analysis was detected between the three tested materials. The immunohistochemical analysis revealed the highest immunopositive area fraction in the 3-month evaluation period. The experimental tricalcium silicate cement performed similarly to Biodentine and MTA regarding the osteopontin expression during perforation repair, suggesting it is a suitable alternative with favourable handling characters.

The antibacterial effect and the incidence of post-operative pain after the application of nano-based intracanal medications during endodontic retreatment: a randomized controlled clinical trial.

OBJECTIVE: This clinical trial aimed to evaluate the effect of nano-silver and nano-calcium hydroxide intracanal medicaments (ICM) during retreatment regarding their antibacterial effect and their effect on post-operative pain and flare-ups. MATERIALS AND METHODS: Sixty-nine patients scheduled for endodontic retreatment were included in this randomized clinical trial and randomly allocated to 3 equal groups (n = 23) according to the type of ICM used. The first microbial sampling (S1) representing the original microbiota was obtained after the removal of the old canal filling. After chemo-mechanical debridement, another sample (S2) was obtained representing the microbial state before ICM application. Patients were randomly allocated to receive either nano-silver (nano-Ag), nano-calcium hydroxide (nano-CH), or calcium hydroxide (CH) as ICM. Patients rated their pain pre-operatively and then after 6, 12, 24, 48, and 72 h. During the second visit (7 days later), the last microbial sample (S3) was obtained after removal of the ICM. Reduction of total bacterial and total E. faecalis counts and the biofilm-forming capability of the existing microbiota were determined. RESULTS: Results showed reduction in total bacterial count, total E. faecalis count and the biofilm-forming,capability of the existing microbiota after chemo-mechanical debridement (S1-S2) and after the application of ICM (S3-S2). However, the reduction after cleaning and shaping was significantly more pronounced (p < 0.001) compared to the effect of ICM application, with no difference between the 3 ICM (p > 0.05). Post-operative pain was significantly reduced at the 48- and 72-h intervals after the application of nano-Ag and nano-CH only (p < 0.001), with no significant difference between these two ICM (p > 0.05). The incidence of flare-ups in all groups was similar (p > 0.05). CONCLUSIONS: The antibacterial effect of the nano-Ag and nano-CH was equivalent to that of CH, but they contributed to better pain control. CLINICAL RELEVANCE: Nanoparticles may have a positive impact on post-endodontic pain.