Antibacterial and antifungal properties of crude extracts and isolated compounds from Lychnophora markgravii.

Antimicrobial activity of dichloromethane and ethanol extracts and five compounds: pinostrobin (I), pinocembrin (II), tectochrysin (III), galangin 3-methyl ether (IV) and tiliroside (V) isolated from Lychnophora markgravii aerial parts against fifteen microorganisms was determined. The structures of these compounds were elucidated based on ESI-MS and NMR spectroscopic data. Both extracts showed antimicrobial activity against several tested microorganisms. Pinostrobin, tectochrysin and galangin 3-methyl ether showed the strongest antibacterial and antifungal effects.

Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study

OBJECTIVES: The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. MATERIAL AND METHODS: Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12 percent chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5 percent significance level. RESULTS: The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. CONCLUSION: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12 percent chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.

Evaluation of home disinfection protocols for acrylic baseplates of removable orthodontic appliances: A randomized clinical investigation.

INTRODUCTION: In this randomized clinical trial, we investigated, using the microbial culture technique and scanning electron microscopy, the contamination of acrylic baseplates of removable orthodontic appliances by mutans streptococci (MS) and evaluated the efficacy of different home disinfection protocols with a 0.12% chlorhexidine gluconate spray (Periogard, Colgate-Palmolive, São Bernardo do Campo, Brazil). METHODS: Fifteen dental students were randomly enrolled in a 3-stage changeover system with a 1-week interval between each stage. The acrylic baseplates were worn full time except at meals to simulate the routine use of removable appliances under clinical conditions. Three 1-week home disinfection protocols were tested in all stages by a different group of students: protocol I, toothbrushing + baseplate brushing + sterile tap water spraying once a day; protocol II, toothbrushing + baseplate brushing + Periogard spraying on the seventh day after appliance placement; and protocol III, toothbrushing + baseplate brushing + Periogard spraying on the fourth and seventh days after appliance placement. After the first week, the volunteers received new baseplates, toothbrushes, and dentifrices, and the regimens were repeated 2 more times. At the end of each week, the baseplates had a randomized disinfection protocol and were sent for microbiologic analysis. A scanning electron microscope was used to examine 3 acrylic baseplates representing each home protocol. The Friedman test (α = 0.05) compared the home protocols for the formation of MS colonies or biofilms on the acrylic surfaces. RESULTS: MS colonies or biofilms were found on all acrylic baseplates after protocol I. Protocols II and III reduced significantly (P <0.05) the number of MS colonies and biofilms on the acrylic surfaces. No significant difference (P >0.05) was observed between protocols II and III. The scanning electron microscope analysis confirmed the results of the microbiologic cultures. CONCLUSIONS: Disinfection of baseplates of removable orthodontic appliances by using 0.12% chlorhexidine spray once or twice a week reduced the contamination by MS on the acrylic surface in vivo.

Microbial culture and checkerboard DNA-DNA hybridization assessment of bacteria in root canals of primary teeth pre- and post-endodontic therapy with a calcium hydroxide/chlorhexidine paste.

AIM: To investigate the root canal microbiota of primary teeth with apical periodontitis and the in vivo antimicrobial effects of a calcium hydroxide/chlorhexidine paste used as root canal dressing. DESIGN: Baseline samples were collected from 30 root canals of primary teeth with apical periodontitis. Then, the root canals were filled with a calcium hydroxide paste containing 1% chlorhexidine for 14 days and the second bacteriologic samples were taken prior to root canal filling. Samples were submitted to microbiologic culture procedure to detect root canal bacteria and processed for checkerboard DNA-DNA hybridization. RESULTS: Baseline microbial culture revealed high prevalence and cfu number of anaerobic, black-pigmented bacteroides, Streptococcus, and aerobic microorganisms. Following root canal dressing, the overall number of cfu was dramatically diminished compared to initial contamination (P <0.05), although prevalence did not change (P > 0.05). Of 35 probes used for checkerboard DNA-DNA hybridization, 31 (88.57%) were present at baseline, and following root canal dressing, the number of positive probes reduced to 13 (37.14%). Similarly, the number of bacterial cells diminished folowing application of calcium hydroxide/chlorhexidine root canal dressing (P = 0.006). CONCLUSION: Apical periodontitis is caused by a polymicrobial infection, and a calcium hydroxide/chlorhexidine paste is effective in reducing the number of bacteria inside root canals when applied as a root canal dressing.

Prevalence of mutans streptococci isolated from complete dentures and their susceptibility to mouthrinses.

The aims of this study were to evaluate the incidence of mutans streptococci (MS - sessile form) on complete maxillary dentures after use of a specific denture paste, and to determine the minimum inhibitory concentration (MIC) and maximum inhibitory dilution (MID) of 3 oral mouthrinses: Cepacol, Plax and Periogard. Seventy-seven complete denture wearers were randomly assigned into 2 groups, according to the product used for denture cleaning: Control group - conventional dentifrice (Kolynos-Super White); and Test group: experimental denture cleaning paste. Denture biofilm was collected at baseline and after 90 and 180 days after treatment by brushing the dentures with saline solution. After decimal serial dilution, samples were seeded onto agar sucrose bacitracin to count colonies with morphological characteristics of MS. MS identification was performed by the sugar fermentation tests. After this procedure, brain heart infusion broth (BHI) was added to oral mouthrinses (Plax, Cepacol e Periogard) and seeded on Petri dishes. The colonies were seeded using the Steers multiplier and, after the incubation, the MIC and MID of the mouthrinses were calculated. The results showed an incidence of 74.0% (n=57) of MS in the 77 complete dentures examined in the study, being 76.3% (n=29) of the Control group (conventional dentifrice) and 71.8% (28) of the Test group (experimental denture cleaning paste). In both groups, the number of positive cases for MS decreased from day 0 to day 180. In the Test group there was a slight decrease in the incidence of Streptococcus mutans 90 days after use of the experimental denture cleaning paste, which was not observed in the Control group. As regards to mouthrinses, for both groups, Periogard showed antimicrobial action with the highest dilution, followed by Cepacol and Plax. In conclusion, the incidence of MS in complete dentures was high and Periogard was the mouthrinse with the strongest antimicrobial action against MS. The experimental denture cleaning paste showed a slight action against S. mutans after 90 days of treatment.

Efficacy of microwaves and chlorhexidine on the disinfection of pacifiers and toothbrushes: an in vitro study.

PURPOSE: The purpose of this study was to evaluate, in vitro, the contamination of toothbrushes and pacifiers by Streptococcus mutans, and the efficacy of microwave and chlorhexidine for their disinfection. METHODS: Sixty pacifiers and 60 toothbrushes were contaminated with S mutans and then divided into groups according to the disinfection protocol: Group 1-chlorhexidine solution; Group 2-microwave sterilization; and Group 3-sterile tap water. The devices were evaluated microbiologically as to the formation of S mutans colonies/biofilms and were examined by scanning electron microscopy. The results were submitted for statistical analysis by Friedman's test at a 5% significance level. RESULTS: The results of both types of evaluation showed a large number of S mutans colonies/biofilms after spraying with sterile tap water, and chlorhexidine spraying and microwaving were effective in eliminate colonies/biofilms. Groups 1 and 2 were statistically similar to each other (P>.05) and differed significantly from Group 3 (P<.05). CONCLUSIONS: The 0.12% chlorhexidine solution spray and 7 minutes of microwave irradiation were effective for disinfection of pacifiers and toothbrushes.

Efficacy of antimicrobial sprays for disinfection of children's toothbrushes: a randomized clinical trial

The objective of this study was to evaluate the efficacy of three spray antimicrobial solutions for the disinfection of childrenÆs toothbrushes. A 4-stage changeover system was used. The solutions studied were: BrushtoxTM (Spray 1), CosmocilTM + basic formula (Spray 2), basic formula (Spray 3), and control û sterile water (Spray 4). Forty children used the solutions in all stages. In each stage, the children received a new toothbrush and performed a single 1-min brushing. Thereafter, the solutions were sprayed six times at different positions on the toothbrush bristles. After four hours, microbiologic culture of the toothbrushes was performed. BrushtoxTM, CosmocilTM + basic formula, and basic formula presented a similar effect on prevention of cariogenic biofilm formation which was better than basic formula alone or sterile water. BrushtoxTM showed the best antimicrobial efficacy.

Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study.

OBJECTIVES: The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. MATERIAL AND METHODS: Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12% chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5% significance level. RESULTS: The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. CONCLUSION: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12% chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.

Morphological differentiation between S. mutans and S. sobrinus on modified SB-20 culture medium.

Due to the major role of Streptococcus mutans and Streptococcus sobrinus in the etiology of dental caries, it is important to use culture media that allow for differentiating these bacterial species. The aim of this study was to evaluate the suitability of a modified SB-20 culture medium (SB-20M) for the isolation and morphological differentiation of S. mutans and S. sobrinus, compared to biochemical identification (biotyping). Saliva samples were collected using the spatula method from 145 children, seeded on plates containing the SB-20M, in which sucrose was replaced by coarse granular cane sugar, and incubated in microaerophilia at 37°C during 72 h. Identification of the microorganisms was performed under stereomicroscopy based on colony morphology of 4904 colonies. The morphological identification was examined by biochemical tests of 94 randomly selected colonies with the macroscopic characteristic of S. mutans and S. sobrinus using sugar fermentation, resistance to bacitracin and production of hydrogen peroxide. There was no statistically significant difference (p>0.05) between morphological identification in the SB-20M medium and biochemical identification (biotyping). Biotyping confirmed that S. mutans and S. sobrinus colonies were correctly characterized in the SB-20M in 95.8% and 95.5% of the cases, respectively. Of the mutans streptococci detected in the children 98% were S. mutans and 2% S. sobrinus. The SB-20M medium is reliable for detection and direct morphological identification of S. mutans and S. sobrinus.

Influence of Er:YAG laser frequency on dentin caries removal capacity.

The purposes of this study were to evaluate in vitro the influence of different frequencies of Er:YAG laser on the human dentin caries removal capacity. Thirty fragments obtained from third molars were randomly assigned into three groups (n = 10) according to the laser frequency used: 4, 6, and 10 Hz. The caries lesion (±1 mm deep) was induced before the irradiation by S.mutans cultures for 6 weeks. The specimens of all groups were irradiated with 200 mJ of energy in noncontact and focused mode under constant refrigeration (water flow: 2.5 mL/min). Quantitative analysis of the caries removal was performed by DIAGNOdent™ and the Axion Vision™ software. Qualitative analysis was performed by Scanning electron microscope (SEM) and light microscope (LM). Data were analyzed by ANOVA and Fishers' tests. The DIAGNOdent™ revealed that the caries removal was similar with 4 and 6 Hz and was superior with 10 Hz (P < 0.05). The analysis with Axion Vision™ software revealed that the caries removal was similar with 6 and 10 Hz and the 4 Hz group promoted the lowest caries removal. Through SEM morphologic analysis, some specimens irradiated with 4 Hz presented, under the demineralized dentin, a disorganized collagenous matrix. The LM images revealed that all frequencies used promoted irregular caries removal, being observed over preparations with 6 and 10 Hz. It can be concluded that the increase of Er:YAG laser frequency provided a higher dentin caries removal without selectivity to the disorganized dentin.

Prevalence of mutans streptococci isolated from complete dentures and their susceptibility to mouthrinses

The aims of this study were to evaluate the incidence of mutans streptococci (MS - sessile form) on complete maxillary dentures after use of a specific denture paste, and to determine the minimum inhibitory concentration (MIC) and maximum inhibitory dilution (MID) of 3 oral mouthrinses: Cepacol, Plax and Periogard. Seventy-seven complete denture wearers were randomly assigned into 2 groups, according to the product used for denture cleaning: Control group - conventional dentifrice (Kolynos-Super White); and Test group: experimental denture cleaning paste. Denture biofilm was collected at baseline and after 90 and 180 days after treatment by brushing the dentures with saline solution. After decimal serial dilution, samples were seeded onto agar sucrose bacitracin to count colonies with morphological characteristics of MS. MS identification was performed by the sugar fermentation tests. After this procedure, brain heart infusion broth (BHI) was added to oral mouthrinses (Plax, Cepacol e Periogard) and seeded on Petri dishes. The colonies were seeded using the Steers multiplier and, after the incubation, the MIC and MID of the mouthrinses were calculated. The results showed an incidence of 74.0 percent (n=57) of MS in the 77 complete dentures examined in the study, being 76.3 percent (n=29) of the Control group (conventional dentifrice) and 71.8 percent (28) of the Test group (experimental denture cleaning paste). In both groups, the number of positive cases for MS decreased from day 0 to day 180. In the Test group there was a slight decrease in the incidence of Streptococcus mutans 90 days after use of the experimental denture cleaning paste, which was not observed in the Control group. As regards to mouthrinses, for both groups, Periogard showed antimicrobial action with the highest dilution, followed by Cepacol and Plax. In conclusion, the incidence of MS in complete dentures was high and Periogard was the mouthrinse with the strongest antimicrobial action against MS. The experimental denture cleaning paste showed a slight action against S. mutans after 90 days of treatment.

O objetivo deste estudo foi avaliar a incidência de estreptococos do grupo mutans (forma séssil) de próteses totais superiores após o uso de uma pasta específica para higienização de próteses totais, bem como determinar a concentração inibitória mínima (CIM) e diluição inibitória máxima (DIM) de 3 enxaguatórios bucais: Cepacol, Plax e Periogard. Setenta e sete usuários de próteses totais foram distribuídos em 2 grupos: (A) grupo Controle: dentifrício convencional (Kolynos Super Branco) e (B) grupo Teste: pasta experimental para higiene de próteses (1). O biofilme das próteses foi coletado no início e após 90 e 180 dias dos tratamentos, por meio de escovação das próteses com solução salina. Após a diluição decimal seriada, as amostras foram semeadas em agar sacarose bacitracina para a contagem de colônias características de estreptococos do grupo mutans. A identificação dos estreptococos do grupo mutans foi realizada por meio de testes de fermentação de açúcares. Após este procedimento, o caldo de infusão de cérebro e coração (BHI) foi adicionado aos antissépticos (Plax, Cepacol e Periogard) e semeado em placas de Petri. As colônias foram semeadas usando o mutiplicador de Steers e após a incubação, a concentração inibitória mínima e a concentração inibitória máxima dos enxaguatórios foram calculadas. Os resultados mostraram que a incidência de estreptococos do grupo mutans nas 77 próteses totais examinadas foi de 74,0 por cento (n=57), sendo 76,3 por cento (n=29) do grupo Controle (pasta convencional) e 71,8 por cento (n=28) do grupo Teste (pasta experimental). Em ambos os grupos, o número de casos positivos para estreptococos do grupo mutans diminuiu, do início (0 dias) para 180 dias. Houve uma pequena diminuição da incidência de Streptococcus mutans após 90 dias do uso da pasta experimental, o que não foi observado no grupo controle. Com relação aos enxaguatórios, para ambos os grupos, o Periogard apresentou atividade antimicrobiana com diluições maiores, seguido do Cepacol e Plax. Pôde-se concluir que a incidência de estreptococos do grupo mutans em próteses totais foi elevada e que o Periogard foi o enxaguatório com melhor ação antimicrobiana contra os estreptococos do grupo mutans. A pasta experimental mostrou uma pequena ação contra S. mutans após 90 dias de tratamento.

Reação inflamatória periapical - repercussões sistêmicas / Apical periondontitis - systemic repercussions

A correlação entre as reações inflamatórias periapicais e a saúde orgânica ainda é um assunto polêmico no meio médico e odontológico. Diversos estudos têm aventado a possibilidade de as reações inflamatórias na região periapical ocasionarem alterações cardiovasculares, doenças respiratórias, diabetes, osteoporose, uveíte, abscesso intracraniano, bacteriospermia e subfertilidade, fascite necrosante, mediastinite e endocardite bacteriana pela disseminação por difusão, planos anatômicos, bactérias via corrente sanguínea, moléculas advindas de microrganismos e mediadores da resposta imune ou inflamatória. Entretanto, uma vez que esses estudos se baseiam em relatos de casos, pesquisas futuras se fazem necessárias para estabelecer os reais mecanismos de disseminação e em que intensidade os microrganismos presentes no biofilme apical, a resposta imuno-inflamatória periapical e as interações antígeno anticorpo são capazes de levar a reações sistêmicas.

The relationship between apical periodontitis and general health is a controversial subject in medical and dental . Several papers have suggested that chronic periapical inflammation may lead to cardiovascular events, respiratory diseases, diabetes, osteoporosis, uveitis, intracranial abscess, mediastinitis, and bacterial endocarditis. These alterations can occur due to dissemination throughout anatomic planes, blood stream bacterial spread, or due to host response against products and by-products from microorganisms. However these pieces of evidence are based on case reports and determination of the mechanisms by which bacteria present in the apical biofilm can reach other parts of the body and elicit systemic disturbances should shed light on this theory.

Apical negative pressure irrigation versus conventional irrigation plus triantibiotic intracanal dressing on root canal disinfection in dog teeth.

OBJECTIVE: The aim of this study was to compare in vivo the efficacy of 2 root canal disinfection techniques (apical negative pressure irrigation versus apical positive pressure irrigation plus triantibiotic intracanal dressing) in immature dog teeth with apical periodontitis. STUDY DESIGN: Two groups of root canals with pulp necrosis and apical periodontitis were evaluated according to the disinfection technique: group 1: apical negative pressure irrigation (EndoVac system); and group 2: apical positive pressure irrigation (conventional irrigation) plus triantibiotic intracanal dressing. The first sample (S1) was collected after lesions were radiographically visible, and the second sample (S2) was collected after apical negative pressure irrigation (group 1) or conventional irrigation/triantibiotic dressing (group 2). All samples were seeded in a culture medium for anaerobic bacteria. Colony-forming unit counts were analyzed statistically by the Mann-Whitney test (alpha = .05). RESULTS: Microorganisms were present in 100% of canals of both groups in S1. In S2, microorganisms were absent in 88.6% of group 1's canals and 78.28% of group 2's canals. There was no significant difference between the groups in either S1 (P = .0963) or S2 (P = .0566). There was significant (P < .05) bacterial reduction from S1 to S2 in both groups. CONCLUSION: In immature teeth with apical periodontitis, use of the EndoVac system can be considered to be a promising disinfection protocol, because it provided similar bacterial reduction to that of apical positive pressure irrigation (conventional irrigation) plus intracanal dressing with the triantibiotic paste, and the use of intracanal antibiotics might not be necessary.

Antimicrobial efficacy of chemical disinfectants on contaminated full metal crowns.

Prosthetic restorations that have been tried in the patient's mouth are potential sources of infection. In order to avoid cross-infection, protocols for infection control should be established in dental office and laboratory. This study evaluated the antimicrobial efficacy of disinfectants on full metal crowns contaminated with microorganisms. Full crowns cast in a Ni-Cr alloy were assigned to one control group (n=6) and 5 experimental groups (n=18). The crowns were placed in flat-bottom glass balloons and were autoclaved. A microbial suspension of each type of strain - S. aureus, P. aeruginosa, S. mutans, E. faecalis and C. albicans- was aseptically added to each experimental group, the crowns being allowed for contamination during 30 min. The contaminated specimens were placed into recipients with the chemical disinfectants (1% and 2% sodium hypochlorite and 2% glutaraldehyde) for 5, 10 and 15 min. Thereafter, the crowns were placed into tubes containing different broths and incubated at 35ºC. The control specimens were contaminated, immersed in distilled water for 20 min and cultured in Thioglycollate broth at 35ºC. Microbial growth assay was performed by qualitative visual examination after 48 h, 7 and 12 days. Microbial growth was noticed only in the control group. In the experimental groups, turbidity of the broths was not observed, regardless of the strains and immersion intervals, thus indicating absence of microbial growth. In conclusion, all chemical disinfectants were effective in preventing microbial growth onto full metal crowns.

Toothbrush contamination by Candida spp. and efficacy of mouthrinse spray for their disinfection.

The aim of the study was to evaluate toothbrush contamination in vivo by Candida spp. and the efficacy of Periogard and Neem Sattiva, in spray, in the disinfection of these toothbrushes. This study was performed in three phases in which mouthrinses and sterile distilled water (control group) were sprayed six times on toothbrush bristles used by 61 university students. Toothbrushes were then submitted to microbiological processing for the isolation and identification of Candida species. Fifty-nine students completed the three phases of this study, and 22 (37.3%) control group toothbrushes presented growth of Candida species. Periogard and Neem Sattiva eliminated growth of Candida spp. in 48.1 and 7.4% of toothbrushes, respectively. Contamination by Candida spp. was observed on various toothbrushes of the control group. Periogard was more efficacious than Neem Sattiva in eliminating growth of Candida spp. on the toothbrush bristles.

Antimicrobial efficacy of chemical disinfectants on contaminated full metal crowns

Prosthetic restorations that have been tried in the patient's mouth are potential sources of infection. In order to avoid cross-infection, protocols for infection control should be established in dental office and laboratory. This study evaluated the antimicrobial efficacy of disinfectants on full metal crowns contaminated with microorganisms. Full crowns cast in a Ni-Cr alloy were assigned to one control group (n=6) and 5 experimental groups (n=18). The crowns were placed in flat-bottom glass balloons and were autoclaved. A microbial suspension of each type of strain - S. aureus, P. aeruginosa, S. mutans, E. faecalis and C. albicans- was aseptically added to each experimental group, the crowns being allowed for contamination during 30 min. The contaminated specimens were placed into recipients with the chemical disinfectants (1 percent and 2 percent sodium hypochlorite and 2 percent glutaraldehyde) for 5, 10 and 15 min. Thereafter, the crowns were placed into tubes containing different broths and incubated at 35ºC. The control specimens were contaminated, immersed in distilled water for 20 min and cultured in Thioglycollate broth at 35ºC. Microbial growth assay was performed by qualitative visual examination after 48 h, 7 and 12 days. Microbial growth was noticed only in the control group. In the experimental groups, turbidity of the broths was not observed, regardless of the strains and immersion intervals, thus indicating absence of microbial growth. In conclusion, all chemical disinfectants were effective in preventing microbial growth onto full metal crowns.

Restaurações protéticas provadas na cavidade bucal dos pacientes são fontes potenciais de infecção. Para evitar infecção cruzada, protocolos de controle de infecção devem ser estabelecidos no consultório e laboratório odontológicos. Este estudo avaliou a eficácia antimicrobiana de desinfetantes químicos em coroas metálicas contaminadas com microorganismos. Coroas totais fundidas com liga de Ni-Cr foram divididas em grupo controle (n=6) e 5 grupos experimentais (n=18). As coroas foram colocadas em balões de vidro e esterilizadas em autoclave. A suspensão microbiana de cada tipo de cepa (S. aureus, P. aeruginosa, S. mutans, E. faecalis e C. albicans) foi assepticamente adicionada a cada grupo experimental, e as coroas foram deixadas contaminar por 30 min. Os corpos-de-prova contaminados foram colocados em recipientes com os desinfetantes químicos (hipoclorito de sódio 1 por cento e 2 por cento e glutaraldeído) por 5, 10 e 15 min. A seguir, as coroas foram colocadas em tubos contendo diferentes meios de cultura e incubadas a 35ºC. Os corpos-de-prova do grupo controle foram contaminados, imersos em água destilada por 20 min e a seguir colocados em tubos de ensaio com meio de cultura Thioglycollate e incubados a 35ºC. A análise do crescimento microbiano foi realizada pelo exame visual qualitativo após 48 h, 7 e 12 dias. Houve crescimento microbiano apenas no grupo controle. No grupo experimental não foi observada turvação dos meios de cultura, independentemente das cepas e períodos de imersão. Conclui-se que todos desinfetantes químicos foram eficazes para prevenir o crescimento microbiano.

Antibacterial activity of propolis-based toothpastes for endodontic treatment / Atividade antibacteriana de pastas dentífricas com base de própolis para tratamento endodôntico

This study evaluated the antibacterial activity of propolis-based toothpastes used as intracanal medication in endodontic treatment. The propolis-based toothpastes were prepared using an extract established in previous studies (identified as A70D and D70D). Calcium hydroxide paste was used as a control. The bacteria employed were Streptococcus mutans (ATCC 25175), Staphylococcus aureus (ATCC 6538), Staphylococcus aureus (ATCC 25923), Kocuria rhizophila (ATCC 9341), Escherichia coli (ATCC 10538), Pseudomonas aeruginosa (ATCC 27853), Enterococcus hirae (ATCC 10541), Streptococcus mutans (ATCC 25175). Five field strains isolated from saliva were used: Staphylococcus spp. (23.1 - coagulase positive), Staphylococcus spp. (23.5 - coagulase negative), Staphylococcus spp. (26.1 - coagulase positive), Staphylococcus spp. (26.5 - coagulase negative) and Staphylococcus epidermidis (6epi). The diffusion-well method on double-layer agar was used in a culture medium of Tryptic Soy Agar. The plates were kept at room temperature for two hours to allow the diffusion of pastes in the culture medium, and then incubated at 35º C for twenty-four hours in aerobiosis and in microaerophilia (S. mutans). After this period, the total diameter of the inhibition halo was measured. The results were analyzed by ANOVA analysis of variance, followed by the Tukey test at p<0.05. The propolis-based toothpastes presented antibacterial activity against 83.3 percent of the analyzed bacteria. For 66.7 percent of these bacteria, the propolis-based toothpastes exhibited greater antibacterial activity than calcium hydroxide. The present results allow us to conclude that the experimental pastes A70D and D70D showed good activity against aerobic bacteria, proving more effective than calcium hydroxide.

O objetivo deste estudo foi avaliar a atividade antibacteriana de formas farmacêuticas a base de própolis para uso no tratamento endodôntico como medicação intracanal. As formulações de própolis, em forma de pastas, foram preparadas a partir de um extrato pré-estabelecido em estudos anteriores e identificadas como A70D e D70D. Como controle, foi utilizado pasta de hidróxido de cálcio. As bactérias utilizadas foram: Streptococcus mutans (ATCC 25175), Staphylococcus aureus (ATCC 6538), Staphylococcus aureus (ATCC 25923), Kocuria rhizophila (ATCC 9341), Escherichia coli (ATCC 10538), Pseudomonas aeruginosa (ATCC 27853), Enterococcus hirae (ATCC 10541), Streptococcus mutans (ATCC 25175) e 5 cepas de campo isoladas da saliva: Staphylococcus spp. (23.1 - coagulase positiva), Staphylococcus spp. (23.5 - coagulase negativa), Staphylococcus spp. (26.1 - coagulase positiva), Staphylococcus spp. (26.5 - coagulase negativa) e Staphylococcus epidermidis (6epi). Foi utilizado o método poço difusão em camada dupla de ágar, em meio de cultura Tryptic Soy Agar. As placas foram mantidas à temperatura ambiente por 2 h para permitir a difusão das pastas no meio de cultura, e então incubadas a 35 ºC por 24 h em aerobiose e em microaerofilia (S. mutans). Após este período, foi medido o diâmetro total do halo de inibição. Os resultados foram submetidos ao teste de análise de variância ANOVA seguido do teste de Tukey com p<0,05. As pastas a base de própolis apresentaram atividade antibacteriana contra 83,3 por cento das bactérias analisadas. Para 66,7 por cento das bactérias, as pastas de própolis apresentaram maior atividade antibacteriana que o hidróxido de cálcio, e este foi mais efetivo apenas para Streptococcus mutans (ATCC 25175), Staphylococcus aureus (ATCC 25923) e Pseudomonas aeruginosa (ATCC 27853). De acordo com a metodologia utilizada, pode-se concluir que as pastas experimentais A70D e D70D apresentam boa atividade contra bactérias aeróbias...

Use of the DNA Checkerboard hybridization method for detection and quantitation of Candida species in oral microbiota.

The DNA Checkerboard method enables the simultaneous identification of distinct microorganisms in a large number of samples and employs up to 45 whole genomic DNA probes to gram-negative and gram-positive bacterial species present in subgingival biofilms. Collectively, they account for 55%-60% of the bacteria in subgingival biofilms. In this study, we present the DNA Checkerboard hybridization as an alternative method for the detection and quantitation of Candida species in oral cavities. Our results reveal that DNA Checkerboard is sensitive enough and constitutes a powerful and appropriate method for detecting and quantifying Candida species found in the oral cavity.

Bacterial culture and DNA Checkerboard for the detection of internal contamination in dental implants.

PURPOSE: The aim of this in vitro study was to evaluate the bacterial leakage along the implant-abutment interface by the conventional bacterial culture and DNA Checkerboard hybridization method. MATERIALS AND METHODS: Twenty Branemark-compatible implants with a 3.75-mm diameter and external hexagonal platform were randomly placed in two groups of ten implant-abutment assemblies each. One group was used to analyze bacterial counts by DNA Checkerboard hybridization and the other by a conventional bacterial culture. Suspensions of Fusobacterium nucleatum (3 microl) were injected into the grooved internal cylinders of each implant assembly, and the abutment was connected by a 32 Ncm torque. The combined implant-abutments were individually placed in tubes containing the CaSaB culture medium and incubated in a bacteriological constant temperature oven for 14 days. The samples were observed daily as to the presence of turbidity, and after the designated time the microorganisms were collected from the implant interiors and analyzed by the two methods. RESULTS: After 14 days, six implant-abutment assemblies showed turbidity. Both methods indicated reduced microorganism counts in samples from the interior of the implant-abutment assemblies after incubation in the culture medium; however, the number of counts of F. nucleatum was higher by the DNA Checkerboard method when compared to the group analyzed by conventional bacterial cultures (p < 0.05). CONCLUSION: The DNA Checkerboard method was shown to be more sensitive than conventional cultures in the detection of microorganisms.

Use of checkerboard DNA-DNA hybridization to evaluate the internal contamination of dental implants and comparison of bacterial leakage with cast or pre-machined abutments.

AIMS: To evaluate the checkerboard DNA-DNA hybridization method for detection and quantitation of bacteria from the internal parts of dental implants and to compare bacterial leakage from implants connected either to cast or to pre-machined abutments. MATERIALS AND METHODS: Nine plastic abutments cast in a Ni-Cr alloy and nine pre-machined Co-Cr alloy abutments with plastic sleeves cast in Ni-Cr were connected to Branemark-compatible implants. A group of nine implants was used as control. The implants were inoculated with 3 microl of a solution containing 10(8) cells/ml of Streptococcus sobrinus. Bacterial samples were immediately collected from the control implants while assemblies were completely immersed in 5 ml of sterile Tripty Soy Broth (TSB) medium. After 14 days of anaerobic incubation, occurrence of leakage at the implant-abutment interface was evaluated by assessing contamination of the TSB medium. Internal contamination of the implants was evaluated with the checkerboard DNA-DNA hybridization method. RESULTS: DNA-DNA hybridization was sensitive enough to detect and quantify the microorganism from the internal parts of the implants. No differences in leakage and in internal contamination were found between cast and pre-machined abutments. Bacterial scores in the control group were significantly higher than in the other groups (P<0.05). CONCLUSION: Bacterial leakage through the implant-abutment interface does not significantly differ when cast or pre-machined abutments are used. The checkerboard DNA-DNA hybridization technique is suitable for the evaluation of the internal contamination of dental implants although further studies are necessary to validate the use of computational methods for the improvement of the test accuracy.