An infection control protocol: effectiveness of immersion solutions to reduce the microbial growth on dental prostheses

This investigation evaluated the effectiveness of an infection control protocol for cleansing and disinfecting removable dental prostheses. Sixty-four dentures were rubbed with sterile cotton swab immediately after they had been taken from patients' mouths. Samples were individually placed in the culture medium and immediately incubated at 37 +/- 2 degreesC. The dentures were scrubbed for 1 min with 4% chlorhexidine, rinsed for 1 min in sterile water and placed for 10 min in one of the following immersion solutions: 4% chlorhexidine gluconate, 1% sodium hypochlorite, Biocide (iodophors) and Amosan (alkaline peroxide). After the disinfection procedures, the dentures were immersed in sterile water for 3 min, reswabbed and the samples were incubated. All samples obtained in the initial culture were contaminated with micro-organisms. All the lower dentures immersed in Biocide showed positive growth, and the upper dentures were positive for growth in six of eight dentures. The 4% chlorhexidine gluconate, 1% sodium hypochlorite and Amosan solutions have been proved effective to reduce the growth of the micro-organisms in the 10 min immersion period. The protocol evaluated in this study seems to be a viable method to prevent cross-contamination between dental personnel and patients.

Biosecurity in public and private office

Biosecurity is currently a concern for all health-related services, including dentistry, since infection control has a relevant importance. In dental practice, health-related occupations have contact with a great number of individuals who are potentially capable to transmit pathogens. This study comprised a descriptive evaluation of the universal precaution measures for infection control adopted by dental practitioners working at public and private offices in the city of Araçatuba, SP. Data collection was performed by a quiz with questions about individual and collective protection equipments. The results showed that the use of caps was reported by 55% of the professionals working at the public sector and 90% for the private sector. The use of masks and gloves was reported by all professionals surveyed; nevertheless, glove change between patients was not reported by 40% of professionals working at the public sector. There were more flaws in public offices as to the use of protective barriers, since except for the use of gloves, gowns and masks, the frequency of use of those barriers was smaller than at private offices.

Antimicrobial activity of disinfectant agents incorporated into type IV dental stone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

HIV attitudes and practices among professors in a Brazilian dental school.

Although there is considerable published research on Acquired Immunodeficiency Syndrome (AIDS), individual biases persist because of lack of information regarding HIV virus transmission. As a result, both infected patients and health care professionals suffer. The objective of this study was to determine if there is prejudice among university professors at the School of Dentistry at Aracatuba's Sao Paulo State University (FOA-UNESP) concerning HIV-positive patients or HIV-positive health care professionals. Out of the seventy-seven professors who responded to the questionnaire, 62.3 percent (forty-eight) stated that they advise their students not to refuse to treat a patient with HIV. Although 96.2 percent (fifty-two) of the fifty-four professors who treat patients have reported that they treat patients who are HIV-positive, only 65.3 percent of them were aware of infection control precautions, and only 32.7 percent reported that they would treat an HIV-positive patient like any other patient. There is also prejudice regarding HIV-positive professionals because only 48.1 percent (thirty-seven) of the professors responded that they would be willing to be treated by an infected professional. It can be concluded that there is prejudice among some of the FOA-UNESP university professors regarding individuals who are HIV-positive.

Influence of microwave sterilization on the cutting capacity of carbide burs

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Densitometric analysis of the autogenous demineralized dentin matrix on the dental socket wound healing process in humans

The aim of this study was to evaluate the effects of the autogenous demineralized dentin matrix (ADDM) on the third molar socket wound healing process in humans, using the guided bone regeneration technique and a polytetrafluoroethylene barrier (PTFE). Twenty-seven dental sockets were divided into three groups: dental socket (Control), dental socket with PTFE barrier (PTFE), and dental socket with ADDM slices associated to PTFE banier (ADDM + PTFE). The dental sockets were submitted to radiographic bone densitometry analysis and statistical analysis on the 15th, 30th, 60th and 90th days using analysis of variance (ANOVA) and Tukey's test (p ≤ 0.05). The radiographic analysis of the ADDM + PTFE group showed greater homogeneity of bone radiopacity than the Control group and the PTFE group, during all the observation times. The dentin matrix gradually disappeared from the dental socket during the course of the repair process, suggesting its resorption during the bone remodeling process. It was concluded that the radiographic bone density of the dental sockets treated with ADDM was similar to that of the surrounding normal bone on the 90th day. The ADDM was biocompatible with the bone tissue of the surgical wounds of human dental sockets. The radiographic analysis revealed that the repair process was discreetly faster in the ADDM + PTFE group than in the Control and PTFE groups, although the difference was not statistically significant. In addition, the radiographic image of the ADDM + PTFE group suggested that its bone architecture was better than that of the Control and PFTE groups.

Immune response to Mycobacterium bovis-an5 infection in genetically selected mice (selection IV-A)

Mice genetically selected for high (H) and low (L) antibody production (Selection IV-A) were used as murine experimental model. The aim of the present work was to evaluate the macrophagic activity and to characterize the immune response in Mycobacterium bovis-AN5 infected mice (3×10 7 bacteria). The response profile previously observed in such strains was not similar to that obtained during M. bovis infection; however, it corroborated works carried out using Selection I, which is very similar to Selection IV-A regarding infection by M. tuberculosis and Bacillus Calmette-Guérin (BCG). Considering bacterial recovery, LIV-A mice showed higher control of the infectious process in the lungs than in the spleen, whereas HIV-A mice presented more resistance in the spleen. With respect to macrophagic activity, hydrogen peroxide (H2O 2) was probably not involved in the infection control since there was an inhibition in the production of this metabolite. Nitric oxide (NO) and TNF-α production seemed to be important in the control of bacterial replication and varied according to the strain, period and organ. Evaluation of the antibody production indicated that the multi-specific effect commonly observed in these strains was not the same in the response to M. bovis. Antibody concentrations were higher in LIV-A than in HIV-A mice at the beginning of the infection, being similar afterwards. Such data were compared with delayed-type hypersensitivity (DTH), which was more intense in HIV-A than in LIV-A mice, indicating that antibody production is independent of the capability to trigger DTH reactions and that cellular and humoral responses to M. bovis antigens show a polygenic control and an independent quantitative genetic regulation. Differences were observed among organs and metabolites, suggesting that different mechanisms play an important role in this infection in natural heterogeneous populations, indicating that NO, TNF-α and Th1 cytokines are involved in the infection control.

Effectiveness of six different disinfectants on removing five microbial species and effects on the topographic characteristics of acrylic resin

Purpose: The aim of this study was to evaluate the effectiveness of disinfectant solutions (1% sodium hypochlorite, 2% chlorhexidine digluconate, 2% glutaraldehyde, 100% vinegar, tabs of sodium perborate-based denture cleanser, and 3.8% sodium perborate) in the disinfection of acrylic resin specimens (n = 10/group) contaminated in vitro by Candida albicans, Streptococcus mutans, S. aureus, Escherichia coli, or Bacillus subtilis as measured by residual colony-forming unit (CFU). In a separate experiment, acrylic resin was treated with disinfectants to monitor potential effects on surface roughness, Ra (μm), which might facilitate microbial adherence. Materials and Methods: Three hundred fifty acrylic resin specimens contaminated in vitro with 1×10 6 cells/ml suspensions of standard strains of the cited microorganisms were immersed in the disinfectants for 10 minutes; the control group was not submitted to any disinfection process. Final counts of microorganisms per ml were performed by plating method for the evaluation of microbial level reduction. Results were compared statistically by ANOVA and Tukey's test (p ≤ 0.05). In a parallel study aiming to evaluate the effect of the tested disinfectant on resin surface, 60 specimens were analyzed in a digital rugosimeter before and after ten cycles of 10-minute immersion in the disinfectants. Measurements of superficial roughness, Ra (μm), were compared statistically by paired t-test (p ≤ 0.05). Results: The results showed that 1% sodium hypochlorite, 2% glutaraldehyde, and 2% chlorhexidine digluconate were most effective against the analyzed microorganisms, followed by 100% vinegar, 3.8% sodium perborate, and tabs of sodium perborate-based denture cleanser. Superficial roughness of the specimens was higher after disinfection cycles with 3.8% sodium perborate (p = 0.03) and lower after the cycles with 2% chlorhexidine digluconate (p = 0.04). Conclusion: Within the limits of this experiment, it could be concluded that 1% sodium hypochlorite, 2% glutaraldehyde, 2% chlorexidine, 100% vinegar, and 3.8% sodium perborate are valid alternatives for the disinfection of acrylic resin. © 2008 by The American College of Prosthodontists.

Avaliação das condutas de biossegurança em laboratórios de prótese dentária de João Pessoa, PB, Brasil

Objective: To evaluate the biosecurity measures adopted in dental prosthesis laboratories of the city of João Pessoa, PB, Brazil with respect to prosthetic works sent by dentists. Method: Twenty-five dental prosthesis technicians (DPT) of the city of João Pessoa, PB, filled out a questionnaire referring to their knowledge of the biosecurity principles, disinfection of impressions and other prosthetic items, and the use of individual protection equipment (IPE). Results: Although 92% of the interviewees believed in the possible occurrence of cross-infection between dental prosthesis laboratories and dental offices, 64% declared that the prosthetic works received in their laboratories do not undergo any disinfection procedure. It was also observed that, for disinfection of impressions and stone casts, the chemical substances are not used as recommended by the manufacturers or are innocuous to microorganisms. Regarding the use of IPE, 60% of the DPT used mask, but only 4% used gowns. With respect to the measures taken regarding the impressions received from dental offices, 56% of the interviewees only wash them in running tap water, and 56% of the stone casts that arrive at the laboratory are not disinfected in any way. Conclusion: There is a need for more motivation and instructions to DPT regarding the prevention of cross-contamination during sending and receiving of prosthetic works between dental prosthesis laboratories and dental offices because the DPT evaluated in this study were found negligent with respect to disinfection procedures.

Prevention of soil-transmitted helminth infection

Soil-transmitted helminths (STHs) form one of the most important groups of infectious agents and are the cause of serious global health problems. The most important STHs are roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus or Ancylostoma duodenale); on a global level, more than a billion people have been infected by at least one species of this group of pathogens. This review explores the general concepts of transmission dynamics and the environment and intensity of infection and morbidity of STHs. The global strategy for the control of soil-transmitted helminthiasis is based on (i) regular anthelminthic treatment, (ii) health education, (iii) sanitation and personal hygiene and (iv) other means of prevention with vaccines and remote sensoring. The reasons for the development of a control strategy based on population intervention rather than on individual treatment are discussed, as well as the costs of the prevention of STHs, although these cannot always be calculated because interventions in health education are difficult to measure. An efficient sanitation infrastructure can reduce the morbidity of STHs and eliminates the underlying cause of most poverty-related diseases and thus supports the economic development of a country.

Contaminação microbiana das soluções de processamento radiográfico: Risco de infecção cruzada

Objective: To evaluate the microbial contamination in samples of radiographic developing and fixing solutions, radiographic processing water, dental unit waterlines and dental office's external water supply. Methods: Samples of 50 private dental offices and 20 dental offices of the School of Dentistry de Araçatuba-UNESP were collected. The samples were subjected to neutralization of the residual inhibitory agents followed by pre-enrichment in peptone water and EVA broth and were inoculated in selective and non-selective culture media. The DNA of the samples was extracted and the presence of superinfectant microorganisms was evaluated by PCR. The differences in the prevalence of the microorganisms in the samples of the solutions were analyzed by repeated-measures analysis of variance for category data, while the Chi-Square and Mann-Whitney tests were used to evaluate the existence of associations between the total number of heterotrophic microorganisms and infection control protocols. The significance level was set at 5%. Results: Samples of radiographic fixing solution presented a remarkably less frequent contamination than radiographic developing solution and radiographic processing water. The latter exhibited microorganisms typically originated from the oral microbiota and human skin as well as microorganisms frequently found in dental unit waterlines. There was less contamination of radiographic processing water in the dental offices where the x-ray film packets were disinfected before processing or were covered by a plastic film. Additionally, all samples of dental office's external water supply were drinkable. Conclusion: Covering the x-ray film packets with a plastic film protection barrier was proven the best manner to reduce the contamination of the evaluated solutions.

Necrotizing soft tissue infection of the breast: Case report and literature review

Background: Necrotizing soft tissue infection (NSTI) is characterized by progressive infectious gangrene of the skin and subcutaneous tissue. Its treatment involves intensive care, broad-spectrum antibiotic therapy, and full debridement. Methods: We present two cases of NSTI of the breast, adding these cases to the 14 described in the literature, reviewing the characteristics and evolution of all cases. Case Report: On the fourth day after mastectomy, a 59-year-old woman with ulcerated breast cancer developed Type I NSTI caused by Pseudomonas aeruginosa, which had a favorable evolution after debridement and broad-spectrum antibiotics. The second patient was a 57-year-old woman submitted to a mastectomy and axillary dissection, who had recurrent seromas. On the 32nd post-operative day, after a seroma puncture, she developed Type II NSTI caused by β-hemolytic streptococci. She developed sepsis and died on the tenth day after debridement, intensive care, and broad-spectrum antibiotics. The cases are the first description of breast NSTI after mammary seroma aspiration and the first report of this condition caused by P. aeruginosa. Conclusion: Necrotizing soft tissue infection is rare in breast tissue. It frequently is of Type II, occurring mainly after procedures in patients with breast cancer. The surgeon's participation in controlling the focus of the infection is of fundamental importance, and just as important are broad-spectrum antibiotic therapy and support measures, such as maintenance of volume, correction of electrolytic disorders, and treatment of sepsis and septic shock. Once the infection has been brought under control, skin grafting or soft tissue flaps can be considered. The mortality rate in breast NSTI is 18.7%, all deaths being in patients with the fulminant Type II form. Surgical oncologists need to be alert to the possibility of this rare condition. © 2012, Mary Ann Liebert, Inc.