Antimicrobial Potential of Cannabinoids: A Scoping Review of the Past 5 Years Maria João Coelho, Maria Duarte Araújo, Márcia Carvalho, Inês Lopes Cardoso, Maria Conceição Manso, et al. Microorganisms, 2025 In the scenario of fighting bacterial resistance to antibiotics, natural products have been extensively investigated for their potential antibacterial activities. Among these, cannabinoids—bioactive compounds derived from cannabis—have garnered attention for their diverse biological activities, including anxiolytic, anti-inflammatory, analgesic, antioxidant, and neuroprotective properties. Emerging evidence suggests that cannabinoids may also possess significant antimicrobial properties, with potential applications in enhancing the efficacy of conventional antimicrobial agents. Therefore, this review examines evidence from the past five years on the antimicrobial properties of cannabinoids, focusing on underlying mechanisms such as microbial membrane disruption, immune response modulation, and interference with microbial virulence factors. In addition, their synergistic potential, when used alongside standard therapies, underscores their promise as a novel strategy to address drug resistance, although further research and clinical trials are needed to validate their therapeutic use. Overall, cannabinoids offer a promising avenue for the development of innovative treatments to combat drug-resistant infections and reduce the reliance on traditional antimicrobial agents.
Degree of Contamination of Gutta-Percha Points by Staphylococcus aureus (MRSA/MSSA) Strains Ana Moura Teles, Cristina Pina, Inês Lopes Cardoso, Antea Tramontana, Miguel Cardoso, et al. International Journal of Molecular Sciences, 2024 Methicillin-resistant Staphylococcus aureus (MRSA) is considered one of the most harmful bacteria to human health. Dentistry, like all healthcare disciplines, places great emphasis on preventing scenarios that may result in cross-infection. Although various tested and already used materials are suitable for filling the root canal system, Gutta-Percha (GP) remains the preferred and widely accepted gold standard. Objective: We performed an in vitro analysis of the contamination of GP points, regarding the strains of Methicillin-resistant (MRSA) and Methicillin-sensitive (MSSA) Staphylococcus aureus, using classical microbiology methods and molecular biology techniques. Methods: Gutta-Percha points of two different brands from opened packages (already in use for 1 month) were collected for analysis. The assessment involved incubating the GP points in Brain Heart Infusion (BHI) medium to detect microbial growth. Growing microorganisms were plated on a selective and differential chromogenic medium for MRSA/MSSA strains, and the identification of isolates was confirmed by Polymerase Chain Reaction (PCR). In the case of microbial growth, the GP point was submitted to a disinfection protocol. Results: From the 315 collected GP points, only 6 (1.9%) resulted in being positive for microbial growth. After confirmation by PCR, only one sample of the six GP points was contaminated by MRSA, and the remaining five were MSSA-contaminated. The disinfection protocol was effective in all contaminated GP points. Conclusions: The Gutta-Percha points from opened pre-sterilized packages showed a very low degree of contamination by MRSA/MSSA. However, the detection of MSSA and MRSA strains raises concerns about potential contamination in dental clinic environments, and this risk cannot be considered negligible.
Relevant factors for dental care in planning the response against covid-19 - a narrative review Inês Lopes Cardoso Journal of Medical Pharmaceutical and Allied Sciences, 2022 The main objective of this work was to analyze, through a review of current references, how different factors correlate to shape the response measures implemented by health authorities to the ongoing pandemic event, in the context of dental care.The COVID-19 pandemic has claimed more than 14million lives directly or indirectly, being a special challenge for society and health care systems. The role of dentists during a pandemic crisis is to provide essential dental care while preventing transmission of the virus. However, this virus has some traits that may increase the risk of cross infection in dental offices, due to aerosols produced during several dental treatments. To address this problem, health authorities have prepared specific protocols to prevent cross-contamination by this virus in dental offices, allowing patients to continue receiving dental care during the pandemic period.
Bacterial Contamination of Gutta-Percha Points From Different Brands and the Efficacy of a Chairside Disinfection Protocol Francesca Bracciale European Endodontic Journal, 2020 Objective: To evaluate the bacterial contamination of different brands of Gutta-Percha (GP) points routinely used in clinical practice and the efficacy of a chairside disinfection protocol with sodium hypochlorite. Methods: GP points (n=240), in sizes A, B, C, D, K15, K20, K25, K30, K35, K40, F1, F2, F3 (Dentsply®, Proclinic®, ProTaper® and R&S®), were randomly sampled from commercial packages already in use. These were added directly to Fluid Thioglycolate Medium (one GP point per tube) and incubated at 37ºC for 21 days. During this period, the presence/absence of turbidity was evaluated. To evaluate the efficacy of a chairside disinfection protocol, all detected contaminated GP points were immersed for 1 minute in 10 mL of 5.25% sodium hypochlorite, followed by 5 minutes in 10 mL of detergent solution (3% Tween 80 and 5% sodium thiosulfate) and a final rinse with 10 mL of sterile distilled water and incubated. The data was analysed using the chi-square test and differences between characteristics of dichotomic variables were performed using the binomial test. The significance level was set at P<0.05. Results: Bacterial growth was observed in 22.9% of the total study samples. Dentsply® and R&S® showed the highest level of contamination, 47.3% each, although without significant differences to the other commercial brands. The most contaminated GP point size was K30 (16.4%). The chairside disinfection protocol was effective in disinfection of 76.4% of GP points (P<0.001). Conclusion: A real small number of GP points in clinical use harboured bacteria, including after the Chairside Disinfection Protocol that, anyway, proved to be effective. No significant difference was observed between tested commercial brands.
Detection of Staphylococcus aureus (MRSA/MSSA) in surfaces of dental medicine equipment Eva Gonçalves, Rui Carvalhal, Rita Mesquita, Joana Azevedo, Maria João Coelho, et al. Saudi Journal of Biological Sciences, 2020 Methicillin-Resistant Staphylococcus aureus (MRSA) represents one of the major causes of nosocomial infections, leading to high mortality. Surfaces in clinics, as well as the attending uniform and the hands of the dental doctor can be MRSA reservoirs. Having this in mind, the purpose of this study was to evaluate the presence of Methicillin-Sensitive Staphylococcus aureus (MSSA) and MRSA on dental medicine equipment surfaces. 354 Samples were collected from six equipment surfaces in six attendance areas before and after patient consultation and cultured in a selective medium. Polymerase Chain Reaction (PCR) was used to confirm the identity of bacterial strains as MRSA or MSSA. Data analysis was performed with chi-square tests with Bonferroni correction. It was observed 55.6% of uncontaminated samples. Contamination was: 17.5% MRSA (5.9% of samples collected before patient attendance and 11.6% after); 39.3% MSSA (14.1% collected before and 25.2% after). The prevalence of MRSA and MSSA was significantly higher after patient care. Integrated Clinic represented the most contaminated attendance area (MRSA − 41.7%, MSSA − 51.2%), the chair arm rest was the most contaminated surface for MRSA (29.7%) and the dental spittoon the most contaminated surface for MSSA (23.5%). Although a low level of contamination was observed, dental clinics, through patients possibly carrying bacteria, may be reservoirs for MRSA and MSSA transmission, and might contribute to potential nosocomial infections.
In vivo evaluation of microbial reduction after chemo-mechanical preparation of necrotic root canals with or without apical periodontitis Ana Moura Teles, M. Conceição Manso, Cristina Pina, José Cabeda Revista Portuguesa De Estomatologia Medicina Dentaria E Cirurgia Maxilofacial, 2014 Objectives Assessment of bacterial reduction after chemo-mechanical preparation (using 3% sodium hypochlorite) with or without intracanal dressing (calcium hydroxide paste (Ca(OH)2) or 2% chlorhexidine digluconate gel (CHX)) in necrotic pulps associated or not with apical lesion. Methods Prospective clinical trial, in 69 adult patient's teeth with pulpal necrosis associated or not with apical periodontitis. Microbiological root-canal-sampling occurred before treatment (S1), after chemo-mechanical preparation (S2) and after 14 days intracanal dressing (S3). Colony Forming Units (CFU) were counted after growth in aerobic, anaerobic and microaerofilic cultures. Comparison of the median CFUs treatments and culture media was done with the Friedman test. Comparison of the intracanal dressing effect at S3 was done with the Wilcoxon and the Mann–Whitney tests. Because of the huge differences in bacterial counts variations were expressed as log 10 to analyze differences among intracanal medication groups. S2 and S3 counts were expressed as percentage of CFU reduction regarding S1 counts. Results Significant differences were detected between S1, S2 and S3 (Friedman test; p Conclusions Treatment significantly reduced the number of bacteria but failed to render all root canals sterile. Ca(OH)2 performed better than CHX gel.
Effectiveness of two intracanal dressings in adult Portuguese patients: A qPCR and anaerobic culture assessment A. M. Teles, M. C. Manso, S. Loureiro, R. Silva, I. G. C. Madeira, et al. International Endodontic Journal, 2014 AIM To quantify bacterial equivalents before and after chemomechanical preparation using 3% sodium hypochlorite (NaOCl) and intracanal dressing with calcium hydroxide paste (Ca(OH)2 ) or 2% Chlorhexidine digluconate gel (CHX) in necrotic pulps associated or not with apical periodontitis and to further compare this quantification with counts of anaerobic microorganisms. METHODOLOGY Prospective clinical trial in 69 single-rooted adult teeth (strict inclusion criteria); CHX group: 34; Ca(OH)2 group: 35. Bacteria samples were taken at baseline (S1), after chemomechanical preparation (S2) and after 14 days of intracanal dressing (S3). Bacterial equivalents were assessed by broad-range real-time polymerase chain reaction (qPCR), and live viable bacteria measured with conventional anaerobic culture (CFU/mL). Descriptive/inferential analysis was performed with spss vs. 20.0 (α = 0.05) using the Kruskal-Wallis, Mann-Whitney and chi-squared tests and Spearman's correlation coefficients. RESULTS Both groups showed a significant decrease between S1 and S2 (Mann-Whitney U-test; P < 0.001) both in qPCR and in culture. In the Ca(OH)2 -group, no variation was observed between S2 and S3 by qPCR and culture. In contrast, the CHX group showed a significant increase from S2 to S3 by both techniques. The two groups were only significantly different in S3 (Mann-Whitney U-test; P ≤ 0.001), with a worse performance in the CHX group. Again, these results were congruent by both approaches. Data from both approaches correlate reasonably (rS < 0.5). CONCLUSIONS Infected root canals contained a high bacterial load, and the chemomechanical root canal preparation reduced bacterial equivalents by 99.1% and anaerobic counts by 98.5%. Intracanal dressings were not efficient at reducing bacterial load, but the 14-day intracanal dressing with Ca(OH)2 performed significantly better than CHX, particularly in cases with apical periodontitis.
Air quality assessment during dental practice: Aerosols bacterial counts in an universitary clinic Patrícia Manarte-Monteiro, Alexandrine Carvalho, Cristina Pina, Hélder Oliveira, Maria Conceição Manso Revista Portuguesa De Estomatologia Medicina Dentaria E Cirurgia Maxilofacial, 2013 Objective The main aim of this study was to assess the clinic atmosphere quality regarding the Index of Air Microbial contamination (IMA), according to dental aerosols bacterial counts, when different dentistry procedures are performed. Material and methods The aerosols generated by dentistry and endodontic procedures were analyzed in 26 dental units of the dental clinic. Blood agar plates ( n = 244) were incubated at 37 °C/48 h and the colony forming units (CFU) were calculated. All statistical analysis methods were conducted using the SPSS ® vs.17.0 software (SPSS Inc., IL, Chicago, USA), using α = 0.05 for the comparison tests used (non parametric tests of Mann–Whitney and Wilcoxon). Results The IMA median value in the dental clinic was of 10.4 CFU/dm 2 /h. Aerosols’ CFU counts were significantly higher at 0.5 m and during endodontic treatments. Longer treatment times were associated with higher CFU counts both in dentistry and endodontic procedures. The use and time of turbine use did not significantly affect the CFU counts. Micrococcus sp., Staphylococcus sp. and Streptococcus sp. were identified with presumptive tests after isolation of representative colonies. Conclusion Considering the IMA, the dental clinic atmosphere quality was found to be good.
Evaluation and insights into chitosan antimicrobial activity against anaerobic oral pathogens E.M. Costa, S. Silva, C. Pina, F.K. Tavaria, M.M. Pintado Anaerobe, 2012 The objective of this study was to assess the antimicrobial capability of non-chemically altered chitosan as an alternative to traditional antimicrobials used in the treatment of oral infections. The action mechanism of chitosan was also ascertained. High and low molecular weight chitosan showed antimicrobial activity at low concentrations for all tested bacteria with the MICs varying between 1 and 7 mg/ml with a drop of efficacy relatively to the action of LMW chitosan. In addition chitosan showed also to be an effective bactericidal presenting bactericidal effect within 8 h at the latest. Additionally the evaluation of chitosan's action mechanism showed that both MWs acted upon the bacterial cell wall and were not capable of interacting with the intracellular substances, as showed by the inefficacy obtained in the flocculation assay.
