Bacterial diversity of periodontal and implant-related sites detected by the DNA Checkerboard method.

The aim of this study was to compare the microbial composition of the subgingival biofilm from teeth and implant sulci in relation to contents originating from internal parts of the implant, abutment and implant prosthesis. Twenty subgingival biofilm samples from the mesial and distal aspects of each tooth/implant and 29 samples from the internal parts of titanium implants, abutments and implant prostheses were evaluated for the presence of 18 bacterial species using DNA Checkerboard and the differences between samples from teeth and implants were assessed with Pearson's correlation analysis. The periodontal and peri-implantar sulci presented significantly higher bacterial counts than the implant-related sites (p < 0.05 and p < 0.01, respectively). The highest counts were observed for Capnocytophaga gingivalis, Prevotella intermedia, P. nigrescens and P. micra. The correlation between the counts in the periodontal and peri-implantar sulci was r = 0.66 (p < 0.001). Weaker correlations between samples from the internal parts of the implants and periodontal sulcus (r = 0.49; p < 0.001) or peri-implant sulcus (r = 0.42; p < 0.001) were found. All 18 bacterial species were detected to be colonising the subgingival sulcus of teeth and implants, and implant components in the evaluated patients. Significant correlations between the microbiota were found, the strongest being between the periodontal and peri-implantar sulci.

Bacterial leakage along the implant-abutment interface of premachined or cast components.

In recent clinical studies, contamination of the inner parts of dental implants through bacterial penetration along the implant components has been observed. The aim of the present in-vitro study was to investigate leakage of Fusobacterium nucleatum through the interface between implants and premachined or cast abutments. Both premachined (n=10) and cast (n=10) implant-abutment assemblies were inoculated with 3.0 microL of microbial inoculum. The assemblies were completely immersed in 5.0 mL of tryptic soy broth culture medium to observe leakage at the implant-abutment interface after 14 days of anaerobic incubation. Bacterial growth in the medium, indicative of microbial leakage, was found only in 1 out of 9 samples (11.1%) in each group. Both premachined and cast abutments connected to external hexagonal implants provide low percentages of bacterial leakage through the interface in in vitro unloaded conditions if the manufacturer's instructions and casting procedures are properly followed.

Methods of experimental induction of periapical inflammation. Microbiological and radiographic evaluation.

AIM: To evaluate the influence of coronal filling and apical perforation on the induction of periapical inflammation. METHODOLOGY: Fifty-eight root canals in the teeth of dogs were divided into four groups. Groups I and II: root canals were exposed for 180 days; groups III and IV: root canals were exposed for 7 days and then the access cavity filled for 53 days. The root apices of groups I and III were perforated after the coronal opening, whilst those of groups II and IV remained intact. Standard radiographs were taken before and after the experimental periods. Digital images of the radiographs were created and then analysed by three examiners. After induction of periapical inflammation, the root canal contents were collected using paper points. Microbiologic evaluation of the type of microorganism was carried out by culture in different growth media. The radiographic and microbiologic data were statistically analysed using anova at a 5% significance level. RESULTS: There were a greater total number of microorganisms in groups I and II (P < 0.05). The number of anaerobes was greater than the number of aerobes (P < 0.05). The size of the periapical radiolucencies were not significantly different between the experimental groups. CONCLUSIONS: The different methods analysed induced similar areas of periapical radiolucency in dogs with predominantly anaerobic bacteria. However, the time required for induction was less when the method with coronal filling was used.

Er:YAG laser: antimicrobial effects in the root canals of dogs' teeth with pulp necrosis and chronic periapical lesions.

OBJECTIVE: Our goal in this study was to evaluate the antimicrobial effect of Er:YAG laser applied after biomechanical preparation of the root canals of dog's teeth with apical periodontitis. BACKGROUND DATA: Various in vitro studies have reported effective bacterial reduction in infected root canals using Er:YAG laser. However, there is no in vivo research to support these results. METHODS: Forty root canals of dogs' premolar teeth with pulp necrosis and chronic periapical lesions were used. An initial microbiological sample was taken, and after biomechanical preparation was carried out, a second microbiological sample was taken. The teeth were divided into two groups: Group I-biomechanical preparation was taken of root canals without Er:YAG laser application; Group II-biomechanical preparation was taken of root canals with Er:YAG laser application using 140-mJ input, 63-mJ output/15 Hz. After coronal sealing, the root canals were left empty for 7 days at which time a third microbiological sample was taken. The collected material was removed from the root canal with a #40 K file and placed in transport media. It was serially diluted and seeded on culture dishes selective for anaerobes, aerobes, and total streptococci. Colony-forming units per milliliter (CFU/mL) were counted. RESULTS: Groups I and II showed an increase of CFU/mL for all microorganisms 7 days after treatment, being statistically significant for anaerobes in Group I and for anaerobes and total streptococci in Group II. When comparing CFU/mL of Groups I and II, there was a statistically significant increase after 7 d for total streptococci in Group II. CONCLUSION: Er:YAG laser applied after biomechanical preparation did not reduce microorganisms in the root canal system.

Trypanocidal and antimicrobial activities of Moquinia kingii.

A chloroform crude extract (aerial part) and two compounds, apigenin (1) and cynaropicrin (2), isolated from Moquinia kingii were evaluated against Trypanosoma cruzi trypomastigotes in vitro. Antimicrobial activity was also screened using twenty-two strains including gram-positive and gram-negative bacteria and the yeasts Candida albicans and C. tropicalis. The chloroform crude extract, fractions and isolated compounds from M. kingii were active for both activities. The IC50 values for trypanocidal activity obtained for cynaropicrin and apigenin were 93.5 microg/ml and 181 microg/ml, respectively, while the minimum inhibitory concentrations (MICs) varied from 100 microg/ml to 2500 microg/ml, against the strains of bacteria and yeasts evaluated.

Bioactivity of crude extracts and some constituents of Blutaparon portulacoides (Amaranthaceae).

Crude extracts (aerial parts and roots, both dried), methylenedioxyflavonol, and a mixture of acyl steryl glycosides isolated from Blutaparon portulacoides, were assayed for their toxicity against Trypanosoma cruzi trypomastigotes and Leishmania amazonensis amastigotes from axenic cultures. The antimicrobial activity was also investigated, in a screening conducted using fifteen strains of Gram-positive and Gram-negative bacteria, along with the yeasts, Candida albicans and Candida tropicalis. To assess the antibacterial activity of the isolated compounds, the minimum inhibitory concentrations (MICs) were determined. There are no reports of acyl steryl glycosides in the genus Blutaparon and their biological activities are being evaluated for the first time.

Prevalence of mutans streptococci in 93 members from six Brazilian families.

Several studies report that mutans streptococci (MS) are closely associated with caries in humans and that there is a correlation between the number of carious lesions and the levels of MS in the saliva of children and adults. The presence of MS in the saliva of 93 members of six Brazilian families with at least 3 generations was investigated. Samples of whole unstimulated saliva were collected and diluted. Aliquots of 50 microliters of each suspension were dropped onto SB20 agar and incubated in a candle jar at 37 degrees C for 72 h. Colonies resembling MS were counted, collected, seeded in thioglycoilate medium and subjected to biochemical typing. Mutans streptococci were isolated from 80 subjects (86.0%) and the counts ranged from 3.0 x 10(2) (log 2.477) to 1.6 x 10(8) (log 8.204) CFU/ml of saliva. All of the 73 adults were colonized by MS, but the bacteria were detected in only 7 (35.0%) of the 20 children evaluated. Streptococcus mutans occurred in 78 subjects (97.5%), and 51 (63.7%) were monocolonized. S. sobrinus occurred in 29 individuals (36.3%) and 2 (2.5%) were monocolonized. Twenty-seven (33.8%) subjects were multicolonized with S. mutans and S. sobrinus. This study showed a high prevalence (86.0%) of mutans streptococci in the saliva of members of the studied families, which suggests the risk of intrafamilial transmission.

[Effect of antiseptic treatment of alveolar surgical wounds on bacterial growth on cotton suture threads]. / Efeito da anti-sepsia da ferida cirúrgica alveolar sobre o crescimento bacteriano em fios de sutura de algodão.

The objective of this study was to evaluate bacterial growth on cotton suture. The efficiency of cetylpyridinium chloride (50%), hydrogen peroxide (3%) and chlorhexidine (0.12%) in antisepsis was investigated. For that, 20 patients who were submitted to extraction of impacted lower third molars were studied. Five days after extraction, samples were obtained from the oral and alveolar sides of the sutures, before and after antisepsis of the wounds, and were submitted to bacteriological analysis. Bacterial growth was observed in all examined samples. The number of streptococci decreased after antisepsis and there were no statistically significant differences between the methods of antisepsis used.

In vitro evaluation of the antimicrobial activity of a castor oil-based irrigant.

The antimicrobial activity of irrigating solutions--Endoquil (castor oil detergent), 2% chlorhexidine gluconate solution, and 0.5% NaOCl solution-was evaluated against gram-positive cocci (Micrococcus luteus, Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus mutans, and Streptococcus sobrinus), gram-negative rods (Escherichia coli and Pseudomonas aeruginosa), and the yeast Candida albicans. Activity was evaluated using the two-layer agar diffusion technique. The base layer was obtained by pouring 10.0 ml of Muller Hinton Medium or 10.0 ml of Brain Heart Infusion agar in a Petri dish. After solidification a 5.0 ml seed layer of Muller Hinton Medium or Brain Heart Infusion agar with inoculum (106/ml) was added. Absorbent paper disks (6.0 mm in diameter) immersed in the solutions were placed at equidistant points. Plates were maintained at room temperature for 2 h for prediffusion of the solutions and incubated at 37 degrees C for 24 h. The candle jar system was used for the Brain Heart Infusion agar plates. All tests were performed in duplicate. After incubation the medium was optimized with 0.05 g% triphenyltetrazolium chlorate gel and inhibition halos were measured. All bacterial strains were inhibited by 2.0% chlorhexidine gluconate. Endoquil was effective against gram-positive microorganisms, and 0.5% NaOCl was effective only against S. aureus.

Microbial contamination of toothbrushes and their decontamination.

PURPOSE: The objective was to determine the level of contamination of toothbrushes by mutans streptococci using microbiological identification, to access the bacterial contamination using scanning electron microscopy (SEM) and to evaluate the efficacy of two toothbrush disinfectants. METHODS: Nineteen children used their toothbrushes once a day, for five consecutive days. The toothbrushes were then immersed into disinfectant solutions for 20 h: Group I--0.12% chlorhexidine gluconate; Group II--1% sodium hypochlorite; Group III--sterile tap water. They were then placed into test tubes containing CaSa B, for 3 to 4 days at 37 degrees C. The number of MS cfu was counted and the toothbrushes were submitted to SEM analysis. RESULTS: There was no bacterial growth in Groups I and II; Group III showed MS growth (range, 21 to 120 cfu). Scanning electron microscopy showed biofilm formation on toothbrush bristles. CONCLUSION: Immersion in 0.12% chlorhexidine gluconate and 1% sodium hypochlorite are efficient methods for toothbrush disinfection.

In vitro evaluation of antimicrobial activity of sealers and pastes used in endodontics.

The antimicrobial activity of four root canal sealers (AH Plus, Sealapex, Ketac Endo, and Fill Canal), two calcium hydroxide pastes (Calen and Calasept), and a zinc oxide paste was evaluated. Seven bacterial strains were used, six of them standard; Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 25922, and Enterococcus faecalis ATCC 10541. There was a wild strain of Streptococcus mutans isolated from saliva obtained in an adult dental clinic. Activity was evaluated using the agar diffusion method with Brain Heart Infusion agar and Müller Hinton medium seeded by pour plate. Calcium hydroxide-based sealers and pastes were either placed directly into 4.0 x 4.0 mm wells or by using absorbent paper points. The plates were kept at room temperature for 2 hr for diffusion. After incubation at 37 degrees C for 24 hr, the medium was optimized with 0.05 g% TTC gel and inhibition haloes were measured. All bacterial strains were inhibited by all materials using the well method. However, when the materials were applied with absorbent paper points, Enterococcus faecalis was not inhibited by zinc oxide, and Pseudomonas aeruginosa was not inhibited by AH Plus, Fill Canal, and the zinc oxide-based paste. We conclude that sealers and pastes presented antimicrobial activity in vitro and culture medium optimization with 0.05 g% TTC gel facilitated observation of the inhibition haloes.

Capacity of denture plaque/biofilm removal and antimicrobial action of a new denture paste.

The efficacy of a paste for complete dentures was analyzed in terms of denture plaque/biofilm removal and antimicrobial action against specific microorganisms by determination of colony forming units of mutans group streptococci and yeast from 120 full denture wearers with a healthy palatine mucosa. The patients were given a questionnaire to evaluate the experimental product in terms of important characteristics. The paste was widely accepted by the patients, and effective in denture plaque removal and antimicrobial action. The species of yeasts most frequently isolated were C. albicans, C. tropicalis and C. glabrata. We conclude that it is possible for complete denture wearers to keep their dentures clean with the regular use of a paste-like hygienic product.

Antimicrobial evaluation of calcium hydroxide in infected dentinal tubules.

The objective of this study was to evaluate the antimicrobial activity of calcium hydroxide in infected dentinal tubules. Four microorganisms, strains of ATCC (Streptococcus faecalis (ATCC-29212), Staphylococcus aureus (ATCC-6538), Bacillus subtilis (ATCC-6633), and Pseudomonas aeruginosa (ATCC-27853)) and one mixture of these were used. These strains were inoculated in brain heart infusion (BHI) and incubated at 37 degrees C for 24 h. Sixty-three human maxillary central incisors were prepared and sterilized by autoclaving. Five groups of 12 teeth each were contaminated for 28 days using new 24-h cultures every 72 h, prepared and adjusted to tube 2 of the MacFarland scale (6 x 10(8) cells/ml). Root canals were then irrigated with 5 ml of saline, dried, and completely filled with calcium hydroxide paste. At intervals of 0, 48, and 72 h, and 7 days, dressings were removed and teeth were immersed in 5 ml of BHI and incubated at 37 degrees C for 48 h to observe the growth and multiplication of the microorganisms. Three uninoculated teeth were maintained in a humid environment as an aseptic control. These teeth were immersed in BHI and maintained at 37 degrees C for 7 days to determine microbial growth. Bacterial growth was shown by turbidity of the culture medium and confirmed by seeding these broths on BHI agar at 37 degrees C for 24 h. The positive BHI tubes were selected, and inoculum was spread on the surface of BHI agar, followed by the same incubation conditions. Gram stain was conducted from BHI growth and from colonies growing on solid medium. Calcium hydroxide in infected dentinal tubules showed no antimicrobial effect on S. faecalis, S. aureus, B. subtilis, P. aeruginosa, or on the bacterial mixture used throughout the experiment.

In vivo antimicrobial activity of 2% chlorhexidine used as a root canal irrigating solution.

The aim of the present study was to evaluate the in vivo antimicrobial activity of 2% chlorhexidine gluconate (FCFRP-USP) used as a root canal irrigating solution in teeth with pulp necrosis and radiographically visible chronic periapical reactions. Culture techniques and measurement of the inhibition zone were used. Twenty-two root canals of incisors and molars of 12 patients were used. After accessing the canal, the first root canal sample was collected with two sterile paper points that were transferred to a tube containing reduced transport fluid. The root canal was instrumented using chlorhexidine solution. A small sterile cotton pellet was placed at the root canal entrance, and the cavity was sealed with zinc oxide-eugenol cement. The canals were maintained empty for 48 h. Three sterile paper points were then introduced to absorb the root canal fluid (second sample). One paper point was placed on an agar plate inoculated with Micrococcus luteus ATCC 9341 and incubated for 24 h at 37 degrees C, and the other two were submitted to microbiological evaluation. Present in 10 cases at baseline, mutans streptococci was reduced by 100% at the second assessment. Treatment showed an efficiency of 77.78% for anaerobic microorganisms at the second assessment. These data suggest that chlorhexidine prevents microbial activity in vivo with residual effects in the root canal system up to 48 h.

Evaluation of the antimicrobial activity of three irrigating solutions in teeth with pulpal necrosis.

The antimicrobial activity of 0.4% papaine gel (FCF-USP), an antibacterial product derived from 3.3% castor oil (IQSC-USP), and 0.5% sodium hypochlorite (FORP-USP) was evaluated in teeth with radiographically visible pulpal necrosis and periapical lesion in vivo. After cavity access, under aseptic conditions, a first harvesting was performed. The 3 irrigating solutions were used for biomechanical preparation. After 72 hours, a second harvesting was performed, also under aseptic conditions. The number of colony forming units (cfu) was counted with a stereomicroscope under reflected light. Castor oil and 0.5% sodium hypochlorite presented similar antimicrobial activities for the reduction of the anaerobe number, S. mutans and streptococci; however, the papaine gel showed lower activity. We conclude that both castor oil and sodium hypochlorite are effective as antimicrobial agents and can be used in the treatment of root canals with pulpal necrosis.

In vitro determination of direct antimicrobial effect of calcium hydroxide.

The objective of this study was to determine in vitro the time required for calcium hydroxide in direct contact with microorganisms to express its antimicrobial effect. The microorganisms used were: Micrococcus luteus (ATCC-9341), Staphylococcus aureus (ATCC-6538), Fusobacterium nucleatum (ATCC-25586), Pseudomonas aeruginosa (ATCC-27853), Escherichia coli, and Streptococcus sp. The strains were cultivated in Brain Heart Infusion (BHI), with the exception of F. nucleatum (BHI-PRAS). Pure and mixed suspensions of the microorganisms were prepared. Paper cones immersed in these substances were covered with calcium hydroxide paste, and after 0, 1, 2, 6, 12, 24, 48, and 72 h and 7 days they were transferred to an appropriate medium to observe the growth and multiplication of the microorganisms. Incubation was conducted at 37 degrees C for 48 h, according to the requirements of oxygen of each microorganism. The antimicrobial effect of calcium hydroxide was shown to occur after 12 h on M. luteus and F. nucleatum, 24 h on Streptococcus sp, 48 h on E. coli, and 72 h on S. aureus and P. aeruginosa. Mixture II (M. luteus + Streptococcus sp + S. aureus) was sensitive to calcium hydroxide antimicrobial potential after 48 h, whereas mixture I (M. luteus + E. coli + P. aeruginosa), mixture III (E. coli + P. aeruginosa), and mixture IV (S. aureus + P. aeruginosa) were inactivated after 72 h of exposure.

Relationship between clinical probing depth and reactivity to the BANA test of samples of subgingival microbiota from patients with periodontitis.

The enzymatic test BANA (N-benzoyl-DL-arginine-naphthylamide) was used to analyze the subgingival microbiota of 28 patients aged 26 to 55 years old with a diagnosis of adult periodontitis. Samples were collected with periodontal curettes at 513 sites, with a mean number of sites of 18.3 +/- 8.8 per patient. The results of the BANA test were correlated with the initial measurements of pocket depth. The data showed a statistically significant correlation between increasing probing depth and a positive BANA test. BANA test detected the presence of BANA-positive microorganisms at sites of < 3 mm probing depth in a statistically significant proportion. Negative (BANA 1) and weakly positive (BANA 2) BANA tests were inversely correlated with increasing pocket depth, and positive (BANA 3) BANA tests were directly correlated with increasing pocket depth. On the basis of the presents results, we consider the BANA test to be of practical applicability in periodontal clinical practice and to represent an important auxiliary diagnostic tool for patients with adult periodontitis.

Candida albicans morphotypes from oral cavity in several families

Se estudiaron 108 personas provenientes de 22 familias compuestas de 3 a 8 miembros cada una, para la búsqueda de morfotipos de candida albicans de la cavidad bucal con o sin piezas dentarias. Por la técnica de phongpaichit et. al., morfotipos idénticos o diferentes fueron detectados en 7 grupos familiares. En 10 familias, c. albicans fue aislada de la familia y de protesis dentarias removibles de un mismo individuo. La franja discontinua, considerada como probable indicador de virulencia fue detectada en 9 (16,7 porciento) de las cepas de c. albicans de personas con dentición completa y de saliva de usuarios y no usuarios de prótesis. La franja continua fue verificada en 5 (83,3 porciento) de las cepas de c. albicans aisladas de un mismo sitio. El morfotipo es simple, fácil de ejecutar, puede servir para detectar infección cruzada y como un posible indicador de riesgo de candidosis. C. albicans fue la especie prevalente (86,4 porciento), detectándose a lo menos en 2 miembros de 14 familias

Determination of the p-monochlorophenol residue in the calcium hydroxide + P-monochlorophenol combination used as an intracanal dressing in pulpless teeth of dogs with induced chronic periapical lesion.

To determine the presence of p-monochlorophenol in the calcium hydroxide (Calen) + p-monochlorophenol combination after its use as intracanal dressing, periapical lesions were induced in 60 root canals of upper and lower premolars of four dogs. After biomechanical preparation, the root canals received the intracanal medication, which was removed from the apical third after 2, 4, 7, and 14 days for chemical analysis by spectrophotometry. The results showed a p-monochlorophenol loss of approximately 50.0% in the dressing after 48 h, with no further significant loss after longer periods of times. p-Monochlorophenol was still present in the medication after 14 days.

Anaerobic microorganisms in root canals of human teeth with chronic apical periodontitis detected by indirect immunofluorescence.

Aiming to assess the presence of selected anaerobic microorganisms in root canals of human teeth with chronic apical periodontitis. 25 central and lateral upper incisors presenting with radiographic evidence of chronic apical periodontitis were studied. The pulp chamber was opened under aseptic conditions and samples of the root canal content were collected with sterile absorbent paper points, which were placed and dispersed in test tubes containing reduced transport medium RTT. Aliquots were dried on glass slides and stained by indirect immunofluorescence for detection of Actinomyces viscosus, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia. The results showed a positive indirect immunofluorescence reaction in 24 of the 25 samples. Fourteen were positive for the specie Actinomyces viscosus, 12 for Prevotella intermedia, 10 for Fusobacterium nucleatum and 4 for Porphyromonas gingivalis. A semiquantitative assay was easily implemented for assessment of degree of infection by the organisms in individual cases.