This work aimed (1) to develop polyacid formulations by the one-step photoreduction of silver nanoparticles (AgNP) in a polyacrylate solution of conventional glass ionomer cement (GIC), imparting ...antibacterial activity; and (2) to evaluate handling and mechanical properties of experimental ionomers in comparison to a commercially available conventional GIC.
Formulations with increasing sub-stoichiometric amounts of AgNO3 were monitored during continuous UV light exposure by UV–vis spectroscopy and analyzed by transmission electron microscopy. The resulted synthesis of formulations containing small and disperse spherical nanoparticles (∼6 nm) were used to design the experimental nano-silver glass ionomer cements (NanoAg-GIC). The cements were characterized as to net setting time and compressive strength according to ISO 9917-1:2007 specifications. The antibacterial activity of these cements was assessed by Ag+ diffusion tests on nutritive agar plates (E. coli) and by MTT assay (S. mutans).
The higher concentration of silver (0.50% by mass) in the matrix of NanoAg-GIC allowed viable net setting time and increased in 32% compressive strength of the experimental cement. All groups containing AgNP induced statistically significant E. coli growth inhibition zones (p-value <.05), indicating diffusion of Ag+ ions on the material surroundings. Metabolic activity of S. mutans grown on NanoAg-GIG with higher concentration of silver was significantly affected compared to control (p-value <.01).
Silver nanoparticles one-step preparation in polyacrylate solution allowed the production of highly bioactive water-based cements within suitable parameters for clinical use and with large potential of dental and biomedical application.
Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and has been considered a risk factor for periodontal disease. The aim of this systematic review and ...meta-analysis was to verify the scientific evidence for the association of periodontal attachment loss with low BMD in postmenopausal women. A systematic search of the literature was performed in databases until August 2016, in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Eligibility criteria included studies that compared clinical attachment loss (CAL) between postmenopausal women with low and normal BMD. Studies using similar methodology, with lower and higher risk of bias, were pooled into 3 different meta-analyses to compare CAL among women with normal BMD, osteoporosis, and osteopenia. In the first meta-analysis, mean CAL was compared among groups. In the other 2 meta-analyses, the mean percentages of sites with CAL ≥4 mm and ≥6 mm were respectively compared among groups. From 792 unique citations, 26 articles were selected for the qualitative synthesis. Eleven of the studies were appraised as presenting low risk of bias, and the association between low BMD and CAL was observed in 10 of these studies. Thirteen cross-sectional articles were included in the meta-analysis for osteoporosis and 9 in the osteopenia analysis. Women with low BMD presented greater mean CAL than those with normal BMD (osteoporosis = 0.34 mm 95% confidence interval (CI), 0.20–0.49, P < 0.001; osteopenia = 0.07 mm 95% CI, 0.01–0.13, P = 0.02). Only studies with lower risk of bias were available for the analysis of CAL severity. Women with low BMD presented more severe attachment loss, represented as mean percentage of sites with CAL ≥4 mm (osteoporosis = 3.04 95% CI, 1.23–4.85, P = 0.001; osteopenia = 1.74 95% CI, 0.36–3.12, P = 0.01) and CAL ≥6 mm (osteoporosis = 5.07 95% CI, 2.74–7.40, P < 0.001). This systematic review and meta-analysis indicates that postmenopausal women with osteoporosis or osteopenia may exhibit greater CAL compared with women with normal BMD.
Transcranial Direct Current Stimulation (tDCS) and Transcranial Magnetic Stimulation (TMS) have been described as promising alternatives to treat different pain syndromes. This study evaluated the ...effects of TMS and tDCS in the treatment of chronic orofacial pain, through a systematic review.
An electronic search was performed in major databases: MEDLINE, Scopus, Web of Science, Cochrane, Embase, LILACS, BBO, Open Gray and CINAHL. The eligibility criteria comprised randomized clinical trials (RCTs) that applied TMS or tDCS to treat chronic orofacial pain. The variables analyzed were pain, functional limitation, quality of life, tolerance to treatment, somatosensory changes, and adverse effects. The risk of bias was assessed through the Cochrane Collaboration tool, and the certainty of evidence was evaluated through GRADE. The protocol was registered in the PROSPERO database (CRD42018090774).
The electronic search resulted in 636 studies. Thereafter, the eligibility criteria were applied and the duplicates removed, resulting in eight RCTs (four TMS and four tDCS). The findings of these studies suggest that rTMS applied to the Motor cortex (M1), the dorsolateral prefrontal cortex (DLPFC) and the secondary somatosensory cortex (S2) provide adequate orofacial pain relief. Two studies reported significant pain improvement with tDCS applied over M1 while the other two failed to demonstrate significant effects compared to placebo.
rTMS, applied to M1, DLPFC or S2, is a promising approach for the treatment of chronic orofacial pain. Moreover, tDCS targeting M1 seems to be also effective in chronic orofacial pain treatment. The included studies used a wide variety of therapeutic protocols. In addition, most of them used small sample sizes, with a high risk of biases in their methodologies, thus producing a low quality of evidence. The results indicate that further research should be carried out with caution and with better-standardized therapeutic protocols.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The
Streptococcus mutans
is commonly find in oral environment in both symbiont and dysbiotic conditions, where for the last one it causes the break in homeostatic balance and, in association with ...other microorganisms’ community, results in dental caries process. Additionally, it is important to determine the low molecular weight metabolites profile from
Streptococcus mutans
to distinguish the endogenous and exogenous compounds from patient subjected to salivary metabolomic studies. Thus, the objective of the present study was to characterize the in vitro metabolomic profile of the maturation of a single-species
Streptococcus mutans
biofilm using metabolomic approach by
1
H-nuclear magnetic resonance (NMR) spectroscopy. A distinct metabolomic profile was observed after 2 days of biofilm maturation, independently of the presence of enamel substrate. Sucrose, lactate, and fructose were the main metabolites responsible for the distinction. The sucrose was consumed by
S. mutans
in higher levels in the initial experimental periods than at 6 days of biofilm growth. Lactate and fructose were the main compounds secreted, regardless of the type of growth, but it was also observed production of propionate, iso-butyrate, and pyruvate. Pyruvate metabolism and glycolysis/gluconeogenesis were the main pathways related to biofilm growth. The results contribute to the determination of compounds that are resulted from oral microbial activity and help to guide further metabolomics studies.
Background
Controversial findings exist in the literature regarding the association between tobacco smoking and development of apical periodontitis or need for root canal treatment, with some studies ...reporting an increase in the prevalence of these outcomes in smokers, whilst others reporting no association.
Aim
To evaluate if there is scientific evidence to support an association between tobacco smoking and a greater prevalence of apical periodontitis and/or root canal treatments.
Data Sources
A systematic search was performed using MeSH terms and free terms in the PubMed, Scopus, Virtual Health Library (VHL), Cochrane library and Open Gray databases.
Study Eligibility Criteria, Participants and Interventions
Observational studies that evaluated the association between smoking and the development or healing of periapical lesion and/or the prevalence of root canal treatment in humans were included.
Study Appraisal and Synthesis Methods
A quality assessment of included studies was performed, and the relevant information and findings were evaluated. A meta‐analysis using nine included studies was performed through RevMan software, and the certainty of evidence was evaluated through GRADE.
Results
Fifteen studies were included, of which 10 were classified as low risk of bias, 4 were considered as moderate risk of bias and 1 as high risk of bias. Ten studies reported that smoking was associated with a greater prevalence of periapical periodontitis and/or root canal treatment. Five studies reported no association. Nine studies were included in the pooled meta‐analysis, comprising two subgroups: apical periodontitis and root canal treatment. From these nine studies, eight studies were included in the apical periodontitis subgroup meta‐analysis and demonstrated that this condition was significantly more prevalent in smokers when compared to the nonsmokers (odds ratio = 2.78CI: 1.60, 4.85, P < 0.001; I2 = 79%; no adjusted odds ratio). Three studies were included in the root canal treatment subgroup meta‐analysis and demonstrated an increased prevalence in smokers when compared to the nonsmokers (odds ratio = 2.73 CI: 1.06, 2.83, P < 0.001; I2 = 72%; no adjusted odds ratio). The pooled meta‐analysis demonstrated that smokers had twice the chance of having apical periodontitis and/or root canal treatment when compared to nonsmokers (odds ratio of 2.42 CI: 1.59, 3.68, P < 0.01; I2 = 85%). The GRADE analysis demonstrated moderate certainty of evidence.
Limitations
Several confounding factors were identified such as misinformation regarding the period of time subjects had smoked, as well as the frequency of smoking and the number of cigarettes consumed. No adjustment in odds ratio data for confounding was performed.
Conclusions and Implications of Key Findings
This systematic review and meta‐analysis indicate that tobacco smokers have an increased prevalence of periapical periodontitis and root canal treatments with moderate certainty of evidence.
Objective
To study the influence of peritoneal dialysis (PD) on the salivary metabolite profile of children and adolescents with renal failure.
Materials and methods
Healthy children/adolescents (
n
...= 31; mean age: 12.18 ± 3.76) and children/adolescents subjected to PD (
n
= 12; mean age: 10.10 ± 4.25) were recruited. Oral health status assessed by the dmft/DMFT and Volpe-Manhold calculus indices. The
1
H spectra were acquired in a 600-MHz Bruker nuclear magnetic resonance spectrometer and were subjected to multivariate analysis using partial least squares discriminant analysis (PLS-DA), orthogonal PLS-DA (O-PLS-DA), and univariate analysis through chi-square and
t
tests (SPSS 20.0, IL, USA), with a significance level of
p
< 0.05.
Results
A similar caries pattern (
p
= 0.57; chi-square test) was observed between the healthy (dmft = 0.72 ± 1.28 and DMFT 0.93 ± 2.30) and PD groups (dmft = 2.14 ± 3.67, DMFT 0.33 ± 0.71) and dental calculus (
p
> 0.05,
t
test). PLS-DA and O-PLS-DA were able to distinguish both groups (ACC = 0.85,
R
2
= 0.80,
Q
2
= 0.15). Salivary metabolites decrease in creatine, propionate, and sugar levels in the PD group and an increase in creatinine, butyrate, and lactate levels when compared with the healthy group.
Conclusions
Children and adolescents subjected to PD have a different salivary metabolic profile from that of their healthy subjects.
Clinical relevance
Complications of peritoneal dialysis procedures could be monitored by proper knowledge of saliva characteristics as predictors of peritonitis-related outcome. The use of metabolomics in pediatric nephrology may be an innovative methodology for the early diagnosis and monitoring of kidney diseases.
Aim
To answer the following focused question: ‘As regards microorganism load reduction for patients undergoing root canal treatment, is the use of ozone therapy comparable to conventional ...chemomechanical techniques using sodium hypochlorite (NaOCl)?’
Data sources
A systematic review was conducted using controlled vocabulary and free‐text key words in the following databases: PubMed, Science Direct, Scopus, Web of Science and Open Grey until 2 November 2018. Additional studies were sought through hand searching of endodontic journals.
Study eligibility criteria, participants and interventions
The inclusion criteria comprised studies that compared microbial reduction in root canals after treatments with ozone and NaOCl in extracted mature human teeth or randomized clinical trials.
Study appraisal and synthesis methods
The quality assessment of included laboratory studies was performed with the following parameters: (i) sample size calculation, (ii) samples with similar dimensions, (iii) control group, (iv) standardization of procedures, (v) statistical analysis and (vi) other risk of bias. For randomized clinical trials, the qualitative analysis of the studies was performed from the bias risk assessment using the tool ‘Bias Risk Assessment of Randomized Controlled Studies’ Cochrane Handbook 5.0.2.
Results
The search resulted in 180 published studies. After removal of duplicate studies and full‐text analysis, eight studies were selected and seven were considered low risk of bias (seven ex vivo studies and one random clinical trial). Overall, the results demonstrated that ozone therapy provides significantly less microbial load reduction than NaOCl. As an adjunct in chemomechanical preparation, ozone was ineffective in increasing the antimicrobial effect of NaOCl. Ozone performance was strongly associated with the application protocol used: it is dose, time and bacterial strain dependent, besides the correlation with the use of complementary disinfection sources.
Limitations
A restricted number of randomized clinical trial was found, and the difference amongst the methodology of the studies did not allow a meta‐analysis to be performed.
Conclusions and implications of key findings
Although the selected studies had limitations, this review reached a satisfactory methodological and moderate evidence quality contributing to important preliminary information regarding ozone therapy. As regards load reduction of microorganisms for patients undergoing root canal treatment, ozone is not indicated neither to replace nor to complement the antimicrobial action of NaOCl.
Saliva is a biofluid largely used in metabolomics for the assessment of local and systemic diseases. Our group has previously demonstrated the salivary metabolomic signature of children with dental ...caries (Fidalgo et al. Metabolomics 9(3):657–666,
2013
). The aim of the current study was investigation, using NMR spectroscopy, of the changes observed for metabolite markers for caries lesions before and after dental treatment. Saliva from children with and without dental caries before and after treatment was analyzed by NMR. Partial least squared discriminant analysis (PLS-DA) conducted on the spectroscopic data sets showed a clear separation of saliva metabolic profile of children with and without caries, and multilevel PLS-DA demonstrated difference before and after dental treatment. Our results demonstrate that organic acids are associated with disease activity because their reductions were observed after dental treatment. There was a demonstrated reduction here in the levels of acetate, propionate, fatty acid, butyrate and saccharides. We also observed a drop in the level of microorganisms upon dental treatment. The dental treatment therefore modified the properties of the oral cavity, leading to changes in the salivary profiles after treatment.
Aim: This in vivo experimental study investigated bacterial microbiome and metabolome longitudinal changes associated with enamel caries lesion progression and arrest.
Methods: We induced natural ...caries activity in three caries-free volunteers prior to four premolar extractions for orthodontic reasons. The experimental model included placement of a modified orthodontic band on smooth surfaces and a mesh on occlusal surfaces. We applied the caries-inducing protocol for 4- and 6-weeks, and subsequently promoted caries lesion arrest via a 2-week toothbrushing period. Lesions were verified clinically and quantitated via micro-CT enamel density measurements. The biofilm microbial composition was determined via 16S rRNA gene Illumina sequencing and NMR spectrometry was used for metabolomics.
Results: Biofilm maturation and caries lesion progression were characterized by an increase in Gram-negative anaerobes, including Veillonella and Prevotella. Streptococcus was associated caries lesion progression, while a more equal distribution of Streptococcus, Bifidobacterium, Atopobium, Prevotella, Veillonella, and Saccharibacteria (TM7) characterized arrest. Lactate, acetate, pyruvate, alanine, valine, and sugars were more abundant in mature biofilms compared to newly formed biofilms.
Conclusions: These longitudinal bacterial microbiome and metabolome results provide novel mechanistic insights into the role of the biofilm in caries progression and arrest and offer promising candidate biomarkers for validation in future studies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Modern pentathlon is a multidisciplinary sport that involves exhaustive training which can cause tissue damage and metabolic changes. However, few studies have evaluated the metabolic changes that ...occur in pentathletes. Accordingly, we aimed to evaluate the metabolomic profile of pentathletes during a 3-week training period before competition using nuclear magnetic resonance.
Blood samples from 6 members of a Brazilian modern pentathlon team were collected at the beginning (Pre1, Pre2, and Pre3) and end (Post1, Post2, and Post3) of each week. Low molecular-weight metabolite profiles were analyzed by nuclear magnetic resonance spectroscopy, and biochemical markers were assessed using enzyme-linked immunosorbent assays. Data were assessed using partial least-squares discriminant analysis and univariate statistical model.
Metabolic changes were observed between pre- and postdata of each week and over the 3 weeks before the competition in the partial least-squares discriminant analysis. Creatine kinase concentration increased in the first 2 weeks (P = .045 and P = .039), but there was no difference in the last week (P > .05). Lactate levels increased significantly after training in each week (P < .001). Cortisol levels at Post3 were different from all other time points (P < .05) and the concentrations of peroxides increased over the weeks (P < .05). Among all metabolites, sarcosine showed the greatest differences (P = .004) in the pretraining and posttraining periods of the 3 weeks.
Serum analysis of athletes using nuclear magnetic resonance showed metabolic changes depending on the intensity of the training performed each week.
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