Propylene Glycol Potentiates the Inhibitory Action of CTZ Paste on Antibiotic-Resistant Enterococcus faecalis Isolated from the Root Canal: An In Vitro Study.

This study aimed to evaluate if the change of vehicle for CTZ (Chloramphenicol, Tetracycline, zinc oxide, and Eugenol) paste improves the inhibition of Enterococcus faecalis in vitro. The vehicles evaluated alone and mixed with CTZ were Eugenol, propylene glycol (PG), super-oxidized solution (SOS), grapefruit-seed extract (GSE), and 0.9% saline solution as a negative control. A clinical isolate of E. faecalis was morphologically and biochemically characterized, and its antimicrobial susceptibility was tested using 20 antimicrobial agents. Once characterized, the clinical isolate was cultivated to perform the Kirby-Bauer disc diffusion method with paper discs embedded with the different vehicles mixed or used alone, and incubated at 37 °C for 24 h. Data were analyzed using one-way ANOVA, and the means were compared using Tukey test with a significance level of p < 0.05. For vehicles used alone, GSE presented the greatest inhibition showing a statistically significant difference with the rest of the vehicles. When vehicles were mixed with the CTZ paste, PG showed a greater inhibition with a statistically significant difference from the rest of the vehicles. In conclusion, the vehicle used to mix the CTZ paste plays an important role in the inhibition of E. faecalis in vitro; therefore, we consider that this can be an important factor to achieve success in the use of this technique.

Differences in erythrocytes size and shape in prediabetes and diabetes assessed by two microscopy techniques and its association with dietary patterns. Pilot study.

Hemorheology and microcirculation alterations are caused by erythrocyte size and shape (ESS) modifications. People´s diets can alter erythrocyte functions and membrane fluidity by changing cell membrane components. The aim was to identify differences in ESS obtained by scanning electron (SEM) and atomic force microscopy (AFM) in people with prediabetes and type 2 diabetes (T2DM) and assess their relationship with dietary patterns. The study population included 31 participants (14 healthy, 11 with prediabetes, and 6 with T2DM). Dietary intake was assessed by a food frequency questionnaire, and dietary patterns were obtained using principal component analysis. ESS (diameter, height, axial ratio, thickness, and concave depth) were obtained by SEM and AFM. Differences in ESS between groups were observed with SEM (height) and AFM (height, axial ratio, and concave depth). T2DM presented smaller erythrocytes, more elongated and more altered forms. Two dietary patterns were identified: (1) Unhealthy: more refined cereals, high-fat dairy, fast food, sugary beverages, and fewer fruits, fish, seafood, low-fat dairy, and water. (2) Prudent: higher consumption of refined cereals, vegetables, poultry, low-fat dairy and nuts, and lower tortillas, eggs, high-fat dairy, and legumes. Tertile 3 of the Unhealthy dietary pattern had 80% of healthy participants. A difference in diameter and height (0.44 and 0.32 µm, respectively) obtained by SEM was observed when comparing tertile 2 (smaller erythrocytes) versus tertile 3 in the Unhealthy dietary pattern. SEM and AFM are excellent tools to assess ESS. Unhealthy dietary patterns might be associated with altered ESS. HIGHLIGHTS: SEM and AFM are excellent tools to assess erythrocyte size and shape modifications. Two dietary patterns were identified: healthy and prudent. Smaller erythrocytes were observed in the second tertile of the unhealthy pattern.

Anti-Adherence and Antimicrobial Activities of Silver Nanoparticles against Serotypes C and K of Streptococcus mutans on Orthodontic Appliances.

Background and Objectives: Streptococcus mutans (S. mutans) is the main microorganism associated with the presence of dental caries and specific serotypes of this bacteria have been related to several systemic diseases limiting general health. In orthodontics, white spot lesions (WSL), represent a great challenge for clinicians due to the great fluctuation of their prevalence and incidence during conventional orthodontic treatments. Although silver nanoparticles (AgNP) have been demonstrated to have great antimicrobial properties in several microorganisms, including S. mutans bacteria, there is no available information about anti adherence and antimicrobial properties of AgNP exposed to two of the most relevant serotypes of S. mutans adhered on orthodontic materials used for conventional therapeutics. The objective of this study was to determine anti-adherence and antimicrobial levels of AgNP against serotypes c and k of S. mutans on conventional orthodontic appliances. Materials and Methods: An AgNP solution was prepared and characterized using dispersion light scattering (DLS) and transmission electron microscopy (TEM). Antimicrobial and anti-adherence activities of AgNP were determined using minimal inhibitory concentrations (MIC) and bacterial adherence testing against serotypes c and k of S. mutans clinically isolated and confirmed by PCR assay. Results: The prepared AgNP had spherical shapes with a good size distribution (29.3 ± 0.7 nm) with negative and well-defined electrical charges (−36.5 ± 5.7 mV). AgNP had good bacterial growth (55.7 ± 19.3 µg/mL for serotype c, and 111.4 ± 38.6 µg/mL for serotype k) and adherence inhibitions for all bacterial strains and orthodontic wires (p < 0.05). The serotype k showed statistically the highest microbial adherence (p < 0.05). The SS wires promoted more bacterial adhesion (149.0 ± 253.6 UFC/mL × 104) than CuNiTi (3.3 ± 6.0 UFC/mL × 104) and NiTi (101.1 ± 108.5 UFC/mL × 104) arches. SEM analysis suggests CuNiTi wires demonstrated better topographical conditions for bacterial adherence while AFM evaluation determined cell wall irregularities in bacterial cells exposed to AgNP. Conclusions: This study suggests the widespread use of AgNP as a potential anti-adherent and antimicrobial agent for the prevention of WSL during conventional orthodontic therapies and, collaterally, other systemic diseases.

Noninvasive Glucose Measurements Through Transcutaneous Raman Spectroscopy: A Review.

BACKGROUND: People living with diabetes need constant glucose monitoring to avoid health complications. However, they do not monitor their glucose levels as often as recommended, probably because glucose measurement devices can be painful, costly, need testing strips or sensors, require lancing the finger or inserting a sensor with risk of infection, and can be inaccurate or have failures. Therefore, developing new alternatives for noninvasive glucose measurements that overcome these disadvantages is necessary, being Raman spectroscopy (RS) a solution. OBJECTIVE: This review aims to provide an overview of the current glucose-monitoring technologies and the uses and advantages of RS to improve noninvasive transcutaneously glucose-monitoring devices. RESULTS: The skin has been used to assess glucose levels noninvasively because it is an accessible tissue where glucose can be measured in the interstitial fluid (ISF) in the epidermis (especially in the stratum corneum). The most selected skin sites to apply RS for noninvasive glucose measurements were the nailfold, finger, and forearm because, in these sites, the penetration depth of the excitation light can reach the stratum corneum (10-20 µm) and the ISF. Studies found that RS is a good optical technique to measure glucose noninvasively by comparing glucose levels obtained by RS with those from invasive methods such as glucose meters with testing strips during an oral glucose tolerance test (OGTT). CONCLUSIONS: New alternatives for noninvasive glucose measurements that overcome the disadvantages of current devices is necessary, and RS is a possible solution. However, more research is needed to evaluate the stability, accuracy, costs, and acceptance.

Corrigendum to "In Vitro Determination of Genotoxicity Induced by Brackets Alloys in Cultures of Human Gingival Fibroblasts".

[This corrects the article DOI: 10.1155/2020/1467456.].

Application of atomic force microscopy to assess erythrocytes morphology in early stages of diabetes. A pilot study.

The study aim was to assess the application of atomic force microscopy (AFM) to evaluate erythrocyte morphology in early stages of type 2 diabetes mellitus, and the association with biochemical, anthropometric, diet, and physical activity indicators. This was a pilot cross-sectional study with four groups: healthy individuals, people with prediabetes (PDG), metabolic syndrome (MSG), and diabetes mellitus group (DMG). Blood samples were obtained to assess the erythrocyte morphology and biochemical parameters. Anthropometrical measurements were taken. Besides, a diet and a physical activity questionnaire were applied. The evaluation of the erythrocyte morphology through the AFM showed quantitative and qualitative alterations in the cell's form and size. Compared to the healthy group, the PDG had a reduction in height (-0.80 µm, p < 0.05), and an increase in axial ratio (-0.09 µm, p < 0.05); the MSG had lower concave depth (-0.19 µm, p < 0.05); and the DMG had a decreased height (-0.46 µm, p < 0.05) and concave depth (-0.29 µm, p < 0.05), and higher axial ratio (+0.08 µm) and thickness (+0.32 µm, p < 0.05). The PDG vs. DMG had a statistically significant difference in concave depth (+0.23 µm, p < 0.05) and thickness (-0.26 µm, p < 0.05). The MSG was different than the DMG in variables like axial ratio (-0.05 µm) and thickness (-0.25 µm). Besides, higher values of age, HbA1c, triglycerides, body mass index, waist-to-hip ratio, and physical inactivity were associated with altered erythrocyte morphology. AFM is a promising instrument to assess early but subtle changes in erythrocyte morphology (height, axial ratio, concave depth, thickness) before significant pathological conditions, such as type 2 diabetes mellitus. HbA1c might have a major effect in altered morphology, vs. metabolic parameters like high triglycerides, body mass index, waist, and physical inactivity.

Comparison of the retention of conventional dentures after the use of common adhesive brands on poor denture foundations: an in vitro study / Comparación de la retención de dentaduras convencionales con el uso de marcas comerciales de adhesivos en procesos alveolares deficientes: un estudio in vitro

There is no information about the possible impact in denture retention after the use of common denture adhesives (DAs) when poor denture foundations (PDF) are present. Moreover, there is a lack of information about which current formulation provides greater retention and for how long. Twelve models from edentulous patients with different ridge shape and border height were used and complete dentures were manufactured. Four different formulation brands of DAs were tested after 10 minutes and three, six, nine, and 12 hours of DA application using a universal testing machine. The Fittydent® and Fixodent® adhesives had the highest retention at 12 hours. The PDF group increased on average its retention by 400 %. However, the group presented lower retention compared to the good denture foundation group. In conclusion, DAs significantly increased denture retention. The PDF group were the most benefited with the application of DAs. The Fixodent® paste had the highest retention.

No existe información acerca del posible impacto en la retención de dentaduras después del uso de adhesivos dentales comunes (DAs) cuando existen rebordes alveolares deficientes (PDF). Más aun, existe una falta de información acerca de cuál formula actual provee mayor retención y por cuanto tiempo. Doce modelos de pacientes edentulos con diferentes formas y alturas en sus rebordes alveolares fueron usados, y dentaduras completas les fueron realizadas. Cuatro diferentes fórmulas y marcas de DAs fueron evaluadas después de 10 minutos, tres, seis, nueve y 12 horas de que se aplicó el DA usando una maquina universal de pruebas. Los adhesivos Fittydent® y Fixodent® presentaron la retención más alta a las 12 horas. El grupo con PDF incrementó su retención hasta en un 400 %. Sin embargo, el grupo presentó menor retención cuando se comparó con el grupo que posee adecuados procesos alveolares. Los DAs incrementaron significativamente la retención de las dentaduras. El grupo PDF fue el más beneficiado con la aplicación de DAs. La pasta Fixodent® provee la más alta retención.

Dental plaque microbiota of pet owners and their dogs as a shared source and reservoir of antimicrobial resistance genes.

OBJECTIVE: This investigation aimed to detect coincidences in the antimicrobial resistance genes (ARG) profiles between members of a group living in a household and to compare them between other groups in order to establish if an exchange of ARG occurs and if dental plaque microbiota can be considered as a source and reservoir of ARG that can be shared between humans and pets. METHODS: One hundred sixty dental plaque samples were obtained from four groups: Shelter dogs group (n=20), adult pet owners and dogs group (AD group, n=40), adult pet owners, children and dogs group (ACD group, n=60), and adult non-pet owners and children group (AC group, n=40). DNA was obtained, and specific primers with polymerase chain reaction for ARG detection were used. RESULTS: The AD group exhibited the most coincidences in their ARG profiles, 14 (70%) of the 20 profiles coincided in 100% followed by the ACD group with 9 (45%) coincidences. While the AC group was the less coincident group, only 7 (35%) of the 20 profiles coincided. tetM was the most prevalent with 53.1%, followed by tetQ with 52.5% and cfxA with 51.2%, while the less prevalent were tetW with 31.8%, blaTEM-1 with 27.5%, and ermC with 18.7%. CONCLUSION: Dental plaque microbiota can be considered as a source and reservoir of ARG that can be shared between humans and dogs living in a household. The dogs seem to play an important role in the transference of ARG, and the children appear to be the most affected by carrying the most significant number of ARG.

In Vitro Determination of Genotoxicity Induced by Brackets Alloys in Cultures of Human Gingival Fibroblasts.

Orthodontic brackets release ions that can be reabsorbed in the oral mucosa, potentially causing complications, including cytotoxic effects and mutagenic alterations. The aim was to evaluate the genotoxicity induced by orthodontic appliance alloys in cultures of human gingival fibroblasts by comet assay. Eluates were obtained from the following brackets alloys: EconoLine (SS: stainless steel), MiniMirage (Ni-Ti: nickel-titanium), Nu-Edge (Co-Cr: cobalt-chromium), In-Vu (PC-polycrystals (PC) aluminum oxide), and Monocrystal IZE (monocrystalline (MC) aluminum oxide). Each bracket was sterilized and exposed to a corrosive process for 35 days. The obtained eluates were tested for genotoxicity of human gingival fibroblasts (HGFA) by the alkaline comet assay. All study groups showed genotoxic effects; there was a significant difference (p < 0.0001) among groups. The eluates obtained from Ni-Ti showed a 16-times greater genotoxic effect. There were differences in genotoxicity after comparing the Ni-Ti with SS (p < 0.01) and Co-Cr brackets (p < 0.001). The ceramic was more genotoxic than metallic brackets (SS and Co-Cr), but less than the Ni-Ti. This in vitro model will be useful for further study of early DNA damage caused by brackets and other biomaterials used in the oral cavity before their introduction into the clinical setting.

Antimicrobial activity of endodontic sealers and medications containing chitosan and silver nanoparticles against Enterococcus faecalis.

BACKGROUND: The main microorganism associated with the failure of endodontic treatments is Enterococcus faecalis. Although several endodontic therapeutics have demonstrated antimicrobial activity against E. faecalis, the antimicrobial effectiveness of chitosan (CsNPs) and silver nanoparticles (AgNPs) included into conventional endodontic sealers for endodontic therapies is still unclear. AIM: The objective of this study was to evaluate the antibacterial activity increment (AAI) of endodontic sealers containing CsNPs and AgNPs as well as some chemical components against E. faecalis by direct contact assays. METHODS: CsNPs and AgNPs were synthesized by reduction and ionic gelation methods, respectively. Nanoparticles were characterized by dynamic light scattering and energy dispersive X-ray analysis. The bactericidal activity was tested on monolayers on agar plates and collagen membrane surface assays against E. faecalis. RESULTS: The size of CsNPs was 70.6±14.8 nm and zeta potential was 52.0±5.4 mV; the size of AgNPs was 54.2±8.5 nm, and zeta potential was -48.4±6.9 mV. All materials, single or combined, showed an AAI, especially when CsNPs, chlorhexidine (Chx), and the combination of CsNPs-Chx were added. However, the combination of CsNPs-Chx showed the highest (55%) AAI, followed by Chx (35.5%) and CsNPs (11.1%), respectively. There was a significant statistical difference in all comparisons (p < 0.05). Tubliseal (40%) and AH Plus (32%) sealants showed a higher AAI on E. faecalis in the monolayer test and collagen membrane assay analyzed by scanning electron microscopy. CONCLUSIONS: Tubliseal and AH plus sealers combined with nanoparticles, especially CsNPs-Chx, could be used for conventional endodontic treatments in the control of E. faecalis bacteria.

Prevention of infective endocarditis and bacterial resistance to antibiotics: A brief review.

The purpose of this statement is to debate the recommendations of the American Heart Association (AHA) for the prevention of infective endocarditis through an antibiotic prophylaxis protocol and its relation with bacterial resistance to antibiotics. Since dental infections involve biofilms that include several bacterial species (Gram-negative and Gram-positive), it is essential, from the dental point of view, to consider the frequency, magnitude, and duration of bacteremia associated with active dental infections before applying antibiotic prophylaxis. The actual guidelines for antibiotic prophylaxis should be revised according to recent evidence of bacterial resistance. Amoxicillin/clavulanic acid and moxifloxacin should be considered due to their effectiveness against bacteria associated with oral, GU, and GI infections and the low rates of antibiotic resistance associated with these antibiotics, instead of the actual protocol, which includes amoxicillin (2 g) or clindamycin (600 mg) administered an hour before the dental procedures. The breaking point to test the antibiotic bacterial resistance (ABR) had a wide range in the different studies that were analyzed, which could explain the widely varied ABR percentages reported for the various antibiotics used for antibiotic prophylaxis.

Altered erythrocyte morphology in Mexican adults with prediabetes and type 2 diabetes mellitus evaluated by scanning electron microscope.

AIM: To evaluate the erythrocyte morphology in people with prediabetes, T2DM and healthy subjects in a Mexican population and its association with biochemical parameters. METHODS: Cross-sectional study consisted of three groups: healthy (HG), people with prediabetes (PG) and with T2DM (DMG). A blood sample was obtained from all participants to assess the erythrocyte morphology, and levels of HbA1c, glucose and lipid profile. Anthropometrical parameters were also evaluated. RESULTS: It was observed that compared with healthy individuals, people with prediabetes presented a significant decrease in the diameter (-0.08 µm, P = 0.014) and height (-0.07 µm, P = 0.004), as well as people with T2DM (-0.33 µm, P < 0.001 in diameter; and -0.36 µm, P < 0.001 in height). Besides, it was found a significant difference in diameter (-0.25 µm, P < 0.001) and height (-0.29 µm, P < 0.001) between the PG and DMG. No significant differences in the axial ratio between groups. Also, HbA1c, glucose, triglycerides, cholesterol, LDL cholesterol, systolic blood pressure, weight, BMI, waist and hip circumference were significantly associated with diameter and height. CONCLUSIONS: Erythrocyte morphological alterations can serve as an indicator of early diagnosis of T2DM and a factor implicated in the course of the clinical condition, so the correction of these alterations could serve as a treatment for prediabetes and T2DM. It is essential to promote constantly checkups of biochemical and anthropometrical parameters, as well as erythrocyte morphological alterations to prevent the onset of prediabetes and T2DM and possible clinical complications.

Interproximal caries and premature tooth loss in primary dentition as risk factors for loss of space in the posterior sector: A cross-sectional study.

Dental caries-a highly prevalent public health problem in preschoolers and school children-is the main cause of premature dental loss during childhood, and this may be related to loss of space in the posterior sector. The objective of this study was to evaluate whether interproximal caries and premature tooth loss (D and/or E) are risk factors for loss of space in the posterior sector.A comparative cross-sectional study (split-mouth type) was performed in schoolchildren (6-8 years old). Seventeen gypsum models were evaluated. These children presented with unilateral loss of a dental organ or interproximal caries (teeth D and/or E) and without such affectations on the other side. Measurements were made with a digital Vernier caliper. The dependent variable was the difference (loss of space, mm) between the control and case sides. The independent variables were type of affectation (interproximal caries or tooth loss), sex, age, arcade, and number of interproximal surfaces affected.The mean age was 6.82 ±â€Š0.44 years and 64.7% were boys. The average space loss was 1.09 ±â€Š0.18 mm (control vs case; P < .0001). A greater loss of space was observed among those who lost a dental organ than those with interproximal caries (P = .0119). A correlation was observed between the variable loss of space and the number of interproximal surfaces affected (r = 0.5712, P = .0166).Interproximal caries and tooth loss were risk factors for loss of space in the posterior segment in this sample of Mexican schoolchildren.

In vitro retention efficiency of temporary type zinc oxide cement for orthodontic forced eruption.

OBJECTIVE: To assess the retention efficiency of three types of temporary zinc oxide cement trademarks on forced eruption using intracranal wire device. METHODS: An in vitro evaluation included intracanal wire device displacement and detachment at 50g load force for 120 days and then the retention resistance at maximum load force. RESULTS: All groups of temporary zinc oxide cements were efficient to support 50g load forces after 120 days. None statistical differences were found between groups. Zinc oxide cements supported a maximum retention load force, which exceeded in more than 84 times the lowest value obtained in controls (420g). CONCLUSION: Zinc oxide cements are efficient to retain intracanal wire devices on forced eruption processes in vitro and allows removal of both when necessary (wire device and cement, respectively).

Oral findings and its association with prenatal and perinatal factors in newborns.

PURPOSE: This study aimed to determine the frequency of abnormalities in the newborn oral cavity and to evaluate the association with prenatal and perinatal factors. METHODS: This cross-sectional study evaluated 2,216 newborns. Oral findings were assessed in the first 24 hours of life using visual examination. Sex, weight, length, gestational age, and medical disorders at birth were recorded. Maternal demographic and medical information was also obtained. RESULTS: The most common oral findings were Bohn's nodules, Epstein's pearls, and dental lamina cysts. Other intraoral findings included odontogenic cysts, ankyloglossia, and natal teeth, among others. In logistic regression analyses, folic acid consumption during pregnancy was significantly associated with Bohn's nodules (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.23-2.55; P=0.002), Epstein's pearls (OR, 1.63; 95% CI, 1.14-2.33; P=0.007), and dental lamina cysts (OR, 1.45; 95% CI, 1.02-2.05; P=0.038). Moreover, preterm births were negatively associated with prevalence of Bohn's nodules (OR, 0.63; 95% CI, 0.50-0.80; P≤0.0001). Comparison between newborns with and without oral inclusion cysts showed that maternal folic acid and iron intake were significantly different (P<0.05). CONCLUSION: Maternal folic acid and iron intake were associated with the prevalence of oral inclusion cysts.

Determination and identification of antibiotic-resistant oral streptococci isolated from active dental infections in adults.

OBJECTIVE: To determine and identify antibiotic-resistant bacteria (ARB) of oral streptococci from active dental infections in adults and its association with age and gender. MATERIAL AND METHODS: This cross-sectional study included 59 subjects from 18 to 62 years old. Ninety-eighth samples obtained from the subjects were cultivated in agar plates containing antibiotics amoxicillin/clavulanic acid (A-CA), clindamycin, and moxifloxacin (concentrations of 16, 32 or 64 µg/ml). PCR assay was performed to identify bacterial species. RESULTS: The bacterial species that showed more antibiotic-resistance (AR) was S. mutans (45.9%), followed by S. gordonii (21.6%), S. oralis (17.6%), S. sanguinis (9.5%), S. salivarius (5.4%) and S. sobrinus (0%). Moreover, clindamycin (59.4%) showed the highest frequency of AR. Moxifloxacin and A-CA showed an susceptibility >99.1%, while clindamycin showed the lowest efficacy (93.3%); there was a significant statistically difference (p < .01). The age group between 26 and 50 years old (32.2%) and females (28.8%) showed more multiresistance. Clindamycin showed a statistical difference (p < .05) when comparing groups by gender. CONCLUSIONS: Clindamycin was the antibiotic with the highest frequency of ARB and lower bactericidal effect. Moxifloxacin and A-CA showed the highest efficacy and the lowest ARB frequency. Streptococcus mutans was the bacterial specie that showed an increased frequency of AR.

Morphological changes in erythrocytes of people with type 2 diabetes mellitus evaluated with atomic force microscopy: A brief review.

Prevalence of type 2 diabetes mellitus (T2DM) has been increasing worldwide. Cardiovascular diseases are one of the main causes of death among people with T2DM. Morphological changes in erythrocytes have been associated with higher risk of cardiovascular diseases. Atomic force microscopy (AFM) is a new technique that allows non-invasive imaging of cells and the evaluation of changes in mechanical properties. AIM: To evaluate by AFM the erythrocytes morphological changes of people with T2DM METHODS: Search was conducted from in PubMed, ScienceDirect, Scielo, and Lilacs. Erythrocyte, type 2 Diabetes Mellitus and, Microscopy, Atomic Force were the keywords used for the search. Papers included were cross-sectional studies performed in humans. RESULTS: Five of seven articles fulfilled the inclusion criteria. Compared with healthy cells, the erythrocytes from individuals affected by T2DM had morphological changes such as a decreased concave depth, diameter, height and a deformation index, while axial ratio, stiffness, adhesive force, aggregation, and rigidity index were increased. The results regarding the erythrocyte roughness were inconclusive. CONCLUSIONS: The AFM is an excellent instrument to study the altered erythrocytes of subjects affected by T2DM. Morphology changes in erythrocytes could lead to cardiovascular events, which are major complications in people living with this disease.

Stimulatory effect of Aggregatibacter actinomycetemcomitans DNA on proinflammatory cytokine expression by human gingival fibroblasts.

OBJECTIVE: While different virulence factors have been reported of Aggregatibacter actinomycetemcomitans (Aa), there is little information about the stimulatory effect of its DNA. The main purpose of this study was to assess the inflammatory response of human gingival fibroblasts (HGFs) stimulated with A. actinomycetemcomitans DNA. DESIGN: Cytokine levels of IL-6, IL-1α and TNF-α were measured on the supernatant of HGFs activated with 10, 25, 50 and 100µg/ml DNA of Aa during 24h. Primary cultures of HGFs were infected with Aa and its DNA at different times and concentrations to compare its cytotoxic effect. Cell damage and adhesion of Aa to HGFs were evaluated under light microscopy and Scanning electron microscopy respectively. RESULTS: There was a statistical difference (p<0.05) in cytokine expression in HGFs activated by bacterial DNA with a dose dependent on IL-6 expression and a significantly elevated expression of IL-1α and TNF-α compared to Human DNA negative control. Substantial morphological alterations were observed after infection of A. actinomycetemcomitans in HGFs but not with bDNA exposure. Aggregatibacter actinomycetemcomitans showed a high rate of adhesion and cell damage to HGFs after 30min. CONCLUSIONS: Genomic DNA of A. actinomycetemcomitans could be a factor in the pathogenesis of periodontitis that might play a major role in the inflammatory response.

Association of cytokines polymorphisms with chronic peridontitis and rheumatoid arthritis in a Mexican population.

OBJECTIVE: Historically, it has been shown that rheumatoid arthritis (RA) and periodontitis (PE) share pathophysiological similarities and possibly a genetic background. In order to elucidate the genetic background between both diseases, we evaluated the distributions of five SNPs genotypes and all the possible haplotypes composed in subjects with isolated RA, PE, combined diseases and healthy controls. MATERIALS AND METHODS: The study population consisted of 280 Mexican subjects. Genomic DNA was isolated from buccal epithelial cells collected by cheek scrapings and analyzed for the determination of the following SNPs: IL-1α + 4845 (rs17561), IL-1α -889 (rs1800587), IL-1ß + 3954 (rs1143634), IL-1ß -511(rs16944) and TNF-α -308 (rs1800629). RESULTS: After adjustment for age, sex and smoking status, multiple logistic regression analysis revealed a no significant association in the genotype frequencies of TNF-α -308 and IL-1α + 4845 SNPs. Otherwise a significant association was observed in IL-1ß + 3954 and IL-1ß -511 (p < 0.05) while IL-1α -889 was of borderline statistical significance (p = 0.054). Also, we found three negative associated haplotypes with PE: IL-1α + 4845 G/IL-1ß -511 A, IL-1ß + 3954 C/IL-1ß -511 A and interestingly IL-1α -889 C/IL-1ß -511 A also with a positive association with RA. CONCLUSIONS: Some genotypes and haplotypes are associated with the diseases. But it seems that the genetic background of the association between RA and PE needs to be explored deeper.

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes.

(1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria.