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- Detection of Staphylococcus aureus (MRSA/MSSA) in surfaces of dental medicine equipmentPublication . Gonçalves, Eva; Carvalhal, Rui; Mesquita, Rita; Azevedo, Joana; Coelho, Maria João; Magalhães, Ricardo; Ferraz, Maria Pia; Manso, M. Conceição; Gavinha, Sandra; Pina, Cristina Maria San Román Gomes de; Cardoso, Inês LopesMethicillin-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.
- Microorganisms: the reason to perform endodonticsPublication . Teles, Ana Moura; Manso, M. Conceição; Loureiro, Sara; Pina, Cristina Maria San Román Gomes de; Cabeda, José ManuelThat we perform Endodontics because there are microorganisms is now beyond doubt. Nevertheless, not only the microorganisms, but also the host response have a profound effect on the progression of the disease. Many papers confirmed the polymicrobial nature of pulpal and periapical diseases of endodontic origin and the efficiency of the chemo-mechanical procedures based on physical and chemical elimination of their etiologic factors, whose principles were first presented as far as 1928 by Hall. Since not only bacterial load may be related to the clinical outcome, but also the bacterial composition of the microbiological canal ecosystem, we aimed at the enumeration of the microorganisms present in the different types of endodontic infections. Although the emerging picture is clearly a complex one, not allowing clear-cut association of bacteria and clinical situation, only the further pursuit of elucidation of the many factors involved (including geographical variability) will ultimately lead to rational treatment solutions.
- Bacterial contamination of gutta-percha points from different brands and the efficacy of a chairside disinfection protocolPublication . Bracciale, Francesca; Marino, Nicole; Noronha, Anariely; Manso, M. Conceição; Gavinha, Sandra; Cardoso, Inês Lopes; Pina, Cristina Maria San Román Gomes de; Teles, Ana MouraObjective: 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.
- Is MRSA/MSSA a contamination risk on surfaces of the dental equipment?Publication . Gonçalves, Eva; Carvalhal, Rui; Mesquita, Rita; Azevedo, Joana; Coelho, Maria João; Magalhães, Ricardo; Ferraz, Maria Pia; Manso, M. Conceição; Gavinha, Sandra; Cardoso, Inês Lopes; Pina, Cristina Maria San Román Gomes de
- A review of microbiologic root canal sampling: updating an emerging picturePublication . Teles, Ana Moura; Manso, M. Conceição; Pina, Cristina Maria San Román Gomes de; Cabeda, José ManuelObjectives: The significance of microorganisms in root canals with regard to the aetiology of periapical infection and the need for crucial bacteria control during treatment are undeniable. In this study, we report and discuss a review of the literature on Microbiological Root Canal Sampling (MRS). The procedure is analyzed in detail, discussing its powers, limitations and the influence of sample collection procedures on the incidence of true and false positive results. Data sources: MEDLINE/PUBMED, B-On and library files of Oporto University were accessed. Selection: Papers were selected using the keywords: “root canal sampling”; “apical periodontitis”; “endodontic pathogens”; “root canal infection”; “Culture”; “molecular biology”. The references were selected under inclusion criteria such as English language, accessibility, relevance to the theme and scientific rigor. Conclusions: This review illustrated the absolute need to adhere to strict methodology procedures if valid samples are to be obtained. A combination of Culture and molecular identification approaches have confirmed the polymicrobial nature of endodontic infections with a predominance of anaerobic bacteria. Nucleic acid-based techniques provide significant additional information particularly regarding the not-yet-cultivable species of the microbial community, but greatly increase the budget of the procedure. Thus, assessment of the endodontic microflora, in the context of a polymicrobial biofilm ecosystem, and its relevance to endodontic treatments must rely in the complementariness of Culture and Metagenomics approaches as they are neither mutually exclusive nor competitive, but strongly complementary.
- In vivo evaluation of microbial reduction after chemo-mechanical preparation of necrotic root canals with or without apical periodontitisPublication . Teles, Ana Moura; Manso, M. Conceição; Pina, Cristina Maria San Román Gomes de; Cabeda, José ManuelObjectives: 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 < 0.001), showing a significant decrease from S1 to S2 (Wilcoxon test; p < 0.004), followed by a significant increase from S2 to S3 (p < 0.001) for the CHX group, maintenance for the Ca(OH)2 group in aerobic/anaerobic (Wilcoxon test; p = 0.777/0.227), and increase in the microaerofilic culture (Wilcoxon test; p = 0.047). The two groups only differed significantly in S3 (Mann–Whitney test; p ≤ 0.001), with a worse performance in the CHX group. Conclusions: Treatment significantly reduced the number of bacteria but failed to render all root canals sterile. Ca(OH)2 performed better than CHX gel.
- Identification of yeast and non-pigmented cultivable endodontic bacteria in adult portuguese patientsPublication . Teles, Ana Moura; Manso, M. Conceição; Loureiro, Sara Manuela Marinho; Silva, Ricardo; Madeira, Inês; Pina, Cristina Maria San Román Gomes de; Cabeda, José ManuelIntroduction This study has focused on the identification of the yeasts and non-pigmented bacteria present on adult patients with necrosis or apical periodontitis and the ones who resisted chemomechanical preparation and intracanal dressing with calcium hydroxide paste (Ca(OH)2) or 2% chlorohexidine digluconate gel (CHX). Methods 69 single-rooted teeth of adult patients with necrosis associated or not with apical periodontitis were selected (strict inclusion criteria); CHX group: 34 teeth; Ca(OH)2 group: 35 teeth. Bacteria samples were taken at baseline (S1), after chemo-mechanical preparation (S2) and after 14 days of intracanal dressing (S3). Bacteria and fungal presence was evaluate by means of culture in three atmospheres (aerobic, anaerobic, microaerofilic) in appropriate culture broads. Strict techniques were used for serial dilution, plating, incubation and identification. Results The most represented, abundant and prevalent strains of non-pigmented bacteria were Propionibacterium acnes (detected in S1, S2 and S3), Gemella morbillorum and Clostridium difficile. Candida albicans was found in 9 patients. The higher number of isolates proceeded from S1, being S2 the moment with lowest number of isolates. CHX had a worst performance in disinfection of the root canal system; consequently the number of isolates from S3 samples was bigger compared to Ca(OH)2. The number of identified bacterial species per canal/moment of sampling, varied from zero till 5, including yeasts (Candida albicans). Conclusions: Our findings confirm that the microbiota from primary endodontic infections is polymicrobial, and the anaerobes Gram-positive non-pigmented bacteria are well represented. CHX performed worse, consequently the number of isolates from S3 samples was bigger when compared to Ca(OH)2 as well as with diagnosis of necrosis.