A quality assessment of randomized controlled trial reports in endodontics.

AIM: To assess the quality of the randomized clinical trial (RCT) reports published in Endodontics between 1997 and 2012. METHODOLOGY: Retrieval of RCTs in Endodontics was based on a search of the Thomson Reuters Web of Science (WoS) database (March 2013). Quality evaluation was performed using a checklist based on the Jadad criteria, CONSORT (Consolidated Standards of Reporting Trials) statement and SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials). Descriptive statistics were used for frequency distribution of data. Student's t-test and Welch test were used to identify the influence of certain trial characteristics upon report quality (α = 0.05). RESULTS: A total of 89 RCTs were evaluated, and several methodological flaws were found: only 45% had random sequence generation at low risk of bias, 75% did not provide information on allocation concealment, and 19% were nonblinded designs. Regarding statistics, only 55% of the RCTs performed adequate sample size estimations, only 16% presented confidence intervals, and 25% did not provide the exact P-value. Also, 2% of the articles used no statistical tests, and in 87% of the RCTs, the information provided was insufficient to determine whether the statistical methodology applied was appropriate or not. Significantly higher scores were observed for multicentre trials (P = 0.023), RCTs signed by more than 5 authors (P = 0.03), articles belonging to journals ranked above the JCR median (P = 0.03), and articles complying with the CONSORT guidelines (P = 0.000). CONCLUSIONS: The quality of RCT reports in key areas for internal validity of the study was poor. Several measures, such as compliance with the CONSORT guidelines, are important in order to raise the quality of RCTs in Endodontics.

Atraumatic restorative treatment and Carisolv use for root caries in the elderly: 2-year follow-up randomized clinical trial.

OBJECTIVES: New preventive and treatment strategies are required to address the high prevalence of caries among the elderly. The main objective of this study was to analyze the effectiveness of Carisolv® gel to improve the clinical behavior of restorations obtained by atraumatic restorative treatment (ART) in root caries of elderly patients. A secondary objective was to determine the factors associated with the failure of ART restorations after a 2-year follow up. MATERIAL AND METHODS: A randomized controlled trial with 2-year follow-up was designed for this purpose. Candidate caries lesions were randomly assigned to an ART group for root caries treatment with the conventional ART technique, filling with glass ionomer, or an ART + Carisolv® gel for the same ART plus the application of a caries solvent (Carisolv®). Evaluations were conducted at 6, 12, and 24 months. RESULTS: A total of 81 restorations were performed, 37 in the ART group and 44 in the ART + Carisolv® gel group, with 22 and 26 restorations, respectively, surviving at the end of the 24-month follow-up. Survival rates at 24 months did not significantly differ between ART (63 %) and ART + Carisolv® gel (62 %) restorations. The best model for predicting the failure of the restorations included the number of tooth-brushings/day, the presence or not of prosthesis, the anterior or posterior location of the tooth, and the baseline plaque level. CONCLUSION: The application of Carisolv does not modify the survival rate of ART restorations in elderly patients. CLINICAL RELEVANCE: The use of Carisolv gel does not improve the outcomes of atraumatic restorative treatment.

Potential errors and misuse of statistics in studies on leakage in endodontics.

AIM: To assess the quality of the statistical methodology used in studies of leakage in Endodontics, and to compare the results found using appropriate versus inappropriate inferential statistical methods. METHODOLOGY: The search strategy used the descriptors 'root filling' 'microleakage', 'dye penetration', 'dye leakage', 'polymicrobial leakage' and 'fluid filtration' for the time interval 2001-2010 in journals within the categories 'Dentistry, Oral Surgery and Medicine' and 'Materials Science, Biomaterials' of the Journal Citation Report. All retrieved articles were reviewed to find potential pitfalls in statistical methodology that may be encountered during study design, data management or data analysis. RESULTS: The database included 209 papers. In all the studies reviewed, the statistical methods used were appropriate for the category attributed to the outcome variable, but in 41% of the cases, the chi-square test or parametric methods were inappropriately selected subsequently. In 2% of the papers, no statistical test was used. In 99% of cases, a statistically 'significant' or 'not significant' effect was reported as a main finding, whilst only 1% also presented an estimation of the magnitude of the effect. When the appropriate statistical methods were applied in the studies with originally inappropriate data analysis, the conclusions changed in 19% of the cases. CONCLUSIONS: Statistical deficiencies in leakage studies may affect their results and interpretation and might be one of the reasons for the poor agreement amongst the reported findings. Therefore, more effort should be made to standardize statistical methodology.

Trends in World Dental Research: an overview of the last three decades using the Web of Science.

OBJECTIVE: The objective of this paper is to analyse the scientific activity of dental sciences over the last 30 years. MATERIALS AND METHODS: Dental-research output was identified by retrieving all citable dental documents in the Web of Science (WoS) database in the periods 1986-1988, 1996-1998, and 2006-2008. For this, a two-phase search strategy was designed: firstly, output in Dentistry, Oral Surgery, and Medicine (DOSM) Journal Citation Reports (JCR) category journals were compiled; secondly, for journal documents of other JCR categories but related to Dentistry (Non-DOSM), an innovative search strategy was designed based on a double criterion, thematic and institutional. RESULTS: The results showed that DOSM production increased in absolute but decreased in relative terms over the last 30 years. The JCR categories where dental researchers publish also varied. Surprisingly, the geographic distribution of the production shows a growing concentration of the steadily fewer countries, a previously undescribed phenomenon, while the thematic analysis reveals that this production continued to form four broad thematic areas encompassing the remaining specialties: Dental Materials Prosthodontics, Orthodontics, and General Dentistry. CONCLUSIONS: Scientific production in dentistry has changed in the past three decades both quantitatively and qualitatively, as well as their geographical distribution despite being structured around the same specialties. CLINICAL RELEVANCE: In this study, along with some key messages about the key shifts in publication trends, in terms of subject, where published and by whom, we propose a new methodology which could be useful to professionals as well as researchers, in which the exhaustivity and precision rates for scientific information retrieval improve.

Bisphenol-A and chlorinated derivatives in adipose tissue of women.

Bisphenol-A (BPA) and chlorinated derivatives (Cl(x)BPA) were investigated in adipose tissue of women in Southeast Spain. BPA was above limit of detection (LOD) in 11 out of 20 samples (55%). Among Cl(x)BPA, Cl(2)BPA was the most frequent (80%) and abundant, constituting 94.6% of total chlorinated BPA in adipose tissue. Mean +/- S.D. of BPA, monochloro-BPA (ClBPA), dichloro-BPA (Cl(2)BPA), and trichloro-BPA (Cl(3)BPA) were 5.83 +/- 3.48, 3.05 +/- 0.28, 9.21 +/- 9.26, and 0.74 +/- 0.15 ng/g of adipose tissue, respectively. No tetrachloro-BPA (Cl(4)BPA) was found above LOD. There are no published data on BPA in human adipose tissue or on Cl(x)BPA in adipose tissue or blood, limiting comparisons. BPA levels were similar (w/w) to findings in blood (w/v) in other populations and below levels reported in placenta tissue (w/w). Because of the estrogen mimicking effects of BPA and its Cl(x)BPA, further research is needed to explore their combined effects on human health and trends in human exposure.

Determination of bisphenol A and related aromatic compounds released from bis-GMA-based composites and sealants by high performance liquid chromatography.

Most of the composites and sealants used in dentistry are based on bisphenol A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ polymerization is not complete and that free monomers can be detected by different analytic methods. Concerns about the estrogenicity of bisphenol A (BPA) and other aromatic components leached from commercial products have been expressed. We studied biphenolic components eluted from seven composites and one sealant before and after in vitro polymerization using HPLC and gas chromatography/mass spectrometry and we investigated how pH modifications affect the leaching of these components. We found BPA (maximal amount 1.8 microg/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 microg/mg), bisphenol A diglycidylether (6. 1 microg/mg), Bis-GMA (2.0 microg/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of different commercial products were maintained under controlled pH and temperature conditions. Our results confirm the leaching of estrogenic monomers into the environment by Bis-GMA-based composites and sealants in concentrations at which biologic effects have been demonstrated in in vivo experimental models. The main issue with implications for patient care and dentist responsibility is to further determine the clinical relevance of this estrogenic exposure.

Estrogenicity of resin-based composites and sealants used in dentistry.

We tested some resin-based composites used in dentistry for their estrogenic activity. A sealant based on bisphenol-A diglycidylether methacrylate (bis-GMA) increased cell yields, progesterone receptor expression, and pS2 secretion in human estrogen-target, serum-sensitive MCF7 breast cancer cells. Estrogenicity was due to bisphenol-A and bisphenol-A dimethacrylate, monomers found in the base paste of the dental sealant and identified by mass spectrometry. Samples of saliva from 18 subjects treated with 50 mg of a bis-GMA-based sealant applied on their molars were collected 1 hr before and after treatment. Bisphenol-A (range 90-931 micrograms) was identified only in saliva collected during a 1-hr period after treatment. The use of bis-GMA-based resins in dentistry, and particularly the use of sealants in children, appears to contribute to human exposure to xenoestrogens.

The estrogenicity of bisphenol A-related diphenylalkanes with various substituents at the central carbon and the hydroxy groups.

The chemical structure of hydroxylated diphenylalkanes or bisphenols consists of two phenolic rings joined together through a bridging carbon. This class of endocrine disruptors that mimic estrogens is widely used in industry, particularly in plastics. Bisphenol F, bisphenol A, fluorine-containing bisphenol A (bisphenol AF), and other diphenylalkanes were found to be estrogenic in a bioassay with MCF7 human breast cancer cells in culture (E-SCREEN assay). Bisphenols promoted cell proliferation and increased the synthesis and secretion of cell type-specific proteins. When ranked by proliferative potency, the longer the alkyl substituent at the bridging carbon, the lower the concentration needed for maximal cell yield; the most active compound contained two propyl chains at the bridging carbon. Bisphenols with two hydroxyl groups in the para position and an angular configuration are suitable for appropriate hydrogen bonding to the acceptor site of the estrogen receptor. Our data suggest that estrogenicity is influenced not only by the length of the substituents at the bridging carbon but also by their nature. Because diphenylalkane derivatives are widespread and their production and use are increasing, potential exposure of humans to estrogenic bisphenols is becoming a significant issue. The hazardous effects of inadvertent exposure to bisphenol-releasing chemicals in professional workers and the general populations therefore deserve investigation.

In vitro effect of the resin component bisphenol A on substrate adherence capacity of macrophages.

This study was design to investigate the "in vitro" effect of bisphenol A (BPA), a component of resin used in dentistry, on viability, and substrate adherence capacity of macrophages. Peritoneal macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. Viability was determined by trypan blue exclusion. As a test of macrophage adhesion, the adherence capacity of macrophages to a plastic surface was determined and the adherence index was calculated. Assays were conducted in Eppendorf tubes for 60 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2 in air. BPA did not alter significantly macrophage viability at concentrations as high as 10(-5) M, but BPA decreased in a dose-dependent manner the adherence index of rat peritoneal macrophages. Control peritoneal macrophages showed an adherence index = 81.5 +/- 7.9%. In the presence of 10(-8) M BPA, the Al of macrophages decreased to 41.4 +/- 12.2% (p < 0.05). Higher BPA concentrations (10(-7) to 10(-5) M) also caused a significant inhibition of the adherence index. Half-maximal inhibition (IC50) was obtained at 4.92 +/- 0.39 x 10(-6) M BPA. The in vitro study shows that the resin component BPA can alter macrophage adhesion. Taking into account that adhesion is the first step in the phagocytic process of macrophages and in antigen presentation, BPA could inhibit macrophage function and modulate immune and inflammatory responses in dental pulp and periapical tissues.

Computer simulation of elastic constants of hydroxyapatite and fluorapatite.

Hydroxyapatite (HAP) and fluorapatite (FAP) are essential components of dental enamel and bone. In this paper, we report a computational study of the elastic properties of HAP and FAP using ab initio and force field techniques. We have obtained the HAP and FAP elastic stiffness constants in hexagonal symmetry by fitting the Hooke law for both the energy-strain and stress-strain relations. Our ab initio HAP stiffness constants differ from the results of previous calculations, but follow similar trends. The HAP and FAP stiffness constants calculated with the ab initio method are very similar, although FAP is slightly stiffer than HAP in the hexagonal plane, and more compliant along the hexagonal axis. The pseudo-single-crystal HAP experimental stiffness constants in current use are critically reviewed. Combining the data from the ab initio simulations with the experimental FAP stiffness constants, several alternative sets of HAP stiffness constants are proposed. The mismatch in properties between HAP and FAP is evidently too small to assume it to be directly responsible for dental enamel mechanical degradation with fluorosis disease.

The effect of AH 26 and AH Plus on MCF-7 breast cancer cell proliferation in vitro.

AIM: The purpose of this study was to determine whether AH 26 and AH Plus have in vitro oestrogenic effects. METHODOLOGY: MCF-7 breast cancer cells were trypsinized and plated in 24-well plates at initial concentrations of 10,000 cells per well in 5% FBS in DME. Cells were allowed to attach for 24 h; then the seeding medium was replaced with 10% CDHuS-supplemented phenol red-free DME. Different concentrations of the test compound were added to sample wells (AH 26 and AH Plus at 1/100 to 1/1,000,000 dilutions), 10 pM estradiol-17beta to positive controL and no sub-stance to negative control (hormone-free control cells). The assay was stopped after 144 h. RESULTS: AH 26-powder induced MCF-7 cell proliferation in a dose-dependent manner. The cell yield obtained with AH 26-powder at 1/100 dilution sample was 2.5-fold greater than in control cultures. The sam-ple prepared with mixed AH 26 paste/powder 1:1 also induced MCF-7 cell proliferation, but showed less potency than AH 26-powder alone. The cell yield obtained with AH 26 paste/powder at 1/100 dilution sample was 1.9-fold greater than in control cultures. AH Plus did not show in vitro oestrogenic effect. CONCLUSIONS: AH 26 showed in vitro oestrogenic effect, but not AH Plus. The endodontist must consider the possible oestrogenic effect of AH 26, as well as the cytotoxic effects of root filling materials, and avoid the leakage of sealer through the apex during root canal treatment.