Effect of different manipulations on the physical,chemical and microstructural characteristics of Biodentine

ObjectiveThe water to powder ratio and method of mixing is important for the properties of hydraulic cements. For this purpose a number of clinicians prefer premixed materials. Dental manufacturing companies provide predosed materials, however the manufacturer instructions are not always adhered to. The aim of this research is to investigate physical and chemical alterations of the tricalcium silicate‐based cement Biodentine when manipulated according to the manufacturer’s instructions (control) or changing the doses and mixing of the material components.Methods6 groups were constituted according to different mixing and dosing of powder and liquid. The hydrated cements were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Calcium ion concentration of the leachate was also investigated. Assessment of the physical characteristics included setting time and microhardness.ResultsMicrostructural differences were visible only in the Biodentine mixed manually with water, in which early hydration rate was also affected, with lower calcium ion release. Increase of Biodentine liquid increased the calcium ion release, but also increased the setting time. Manual manipulation required more liquid (both water and Biodentine liquid) added to the mixture to guarantee a similar consistency to the control. A decrease in setting time was also noted. All groups showed higher values of microhardness at 24 h compared to the freshly set materials. In the freshly set materials, there was an overall decrease in microhardness in all groups when compared to group control, particularly significant when increasing the dosage of Biodentine liquid.SignificanceWhen mixing Biodentine, altering the mixing procedure in terms of type and amount of liquid added to the powder and mixing device chosen has an effect on the physical, chemical and mechanical characteristics and surface topography of the material, when compared to Biodentine mixed according to the manufacturer’s recommendations. Hence, the manufacturer’s instructions should be strictly followed.     

Evaluation of the salivary function of patients in treatment with radiotherapy for head and neck cancer submitted to photobiomodulation

Background Head and neck radiotherapy is typically associated with toxicities that can have profound effects on the patient''s quality of life. Xerostomia, which may or may not be related to hypofunction of the salivary gland, leading to negative consequences, mainly in quality of life, leaving patients more susceptible to the development of oral mucositis, dental caries, oral infection and difficulties in speech is one of the most common side effects of such treatment. The aim of the present study was to evaluate salivary function of patients in treatment with radiotherapy for head and neck cancer submitted to photobiomodulation. Material and Methods A cross-sectional study with a quantitative approach was carried out in the Dentistry Department of the Hospital de Câncer de Pernambuco between February and September 2019. Results The study sample comprised 23 patients of both genders, treated with radiotherapy for cancer in the head and neck region. The patients were submitted to photobiomodulation with infrared laser, as intraoral applications in order to prevent mucositis and extraoral applications to stimulate salivary glands. The applications were undertaken three times a week on alternate days throughout the radiotherapy period. The following parameters were used: Intraoral 15mW, 12J / cm2, 10s / point, 2.4 J / point, and extraoral 30mW, 7.5J / cm2, 10s / point, 0.3J / point, both with a wavelength of 830nm and area of 0.028cm². Subjective and objective symptoms were evaluated by measuring the unstimulated salivary flow (USF) using the spitting technique before, during and after radiotherapy treatment. For statistical analysis, a significance level of 5% was adopted. Most patients were male (70%) with 60 years of age on average. At the beginning of treatment, 22 patients had USF> 0.2 ml / min (grade 1), at the end of which 15 patients remained unchanged and only 3 patients progressed to grade 3. As for the subjective classification, most (52%) remained in grade 1 (absence of disability) throughout the treatment. Conclusions Based upon the results of this study it was possible to conclude that the use of photobiomodulation did not significantly interfere with the xerostomia complaint of patients in treatment with radiotherapy, however, it does seem to prevent patients from reaching higher degrees of xerostomia taking into account salivary flow measures. Key words:Photobiomodulation, head and neck neoplasms, radiotherapy, xerostomia, saliva.     

Prevalence of psychiatric disorders in the first trimester of pregnancy and factors associated with current suicide risk

This study aimed to describe the prevalence of psychiatric disorders and to identify the factors associated with Current Suicide Risk (CSR) in the first trimester of pregnancy. The Mini-International Neuropsychiatric Interview (M.I.N.I.) was employed to diagnose mental disorders in 239 women enrolled in a prospective cohort in Rio de Janeiro, Brazil. Serum lipids, leptin and socio-economic status were the independent variables. CSR, the dependent variable, was entered as binary (yes/no) variable into crude and adjusted Poisson regression models with robust variances. CSR was found to be the main psychiatric syndrome (18.4%), followed by agoraphobia (17.2%), major depressive disorder (15.1%) and generalized anxiety disorder (10.5%). Women with CSR showed higher mean levels of cholesterol (169.2 vs. 159.2; p=0.017), high density lipoprotein (50.4 vs. 47.7; p=0.031) and low density lipoprotein (102.8 vs. 95.6; p=0.022) when compared to women without CSR. The adjusted regression model showed a higher prevalence ratio (PR) of CSR among pregnant women with generalized anxiety disorder (PR=2.70, 95% CI: 1.36–5.37), with ≥two parturitions (PR=2.46, 95% CI: 1.22–4.93), and with major depressive disorder (PR=2.11, 95% CI: 1.08–4.12). We have shown that generalized anxiety disorder, major depressive disorder and higher parity are associated with CSR in the first trimester of pregnancy.     

Sulfated polysaccharides isolated from the green seaweed Caulerpa racemosa plays antinociceptive and anti-inflammatory activities in a way dependent on HO-1 pathway activation

Objective

Marine algae are abundant sources of sulfated polysaccharides with various biological activities. Consequently, their biomolecules are of great of commercial interest. In this study, we investigated the potential antinociceptive activity of a sulfated polysaccharide obtained from the green seaweed Caulerpa racemosa (CrII) and the involvement of the hemoxigenase-1 (HO-1) pathway in its anti-inflammatory effect.

Methods

We used a systemic evaluation to verify possible toxic effects of Crll after consecutive treatments. Swiss mice and Wistar rats were used for all experiments.

Results

In Swiss mice, CrII (0.01, 0.1 and 1.0 mg/kg) significantly reduced the number of abdominal contortions and the duration of paw licking in the second phase after treatment with acetic acid and formalin, respectively. However, CrII was unable to prolong the reaction time of thermally stimulated animals. The anti-inflammatory effect of CrII (0.01, 0.1 and 1.0 mg/kg) was evidenced by a decreased number of leukocytes in the peritoneal cavities of the rats. CrII (0.01, 0.1 and 1.0 mg/kg) also reduced the amount of paw edema induced by carrageenan (Cg) and dextran. The anti-inflammatory effect of CrII was confirmed by reduced levels of myeloperoxidase in the paw tissue of the Cg groups. After inhibition with ZnPP IX, a specific HO-1 phenotype inhibitor, the anti-inflammatory effect of CrII was no longer observed in Cg-induced paw edema tests. Consecutive Crll (1.0 mg/kg) for 14 days did not change any biochemical or histopathological parameters, or cause mortality of mice.

Conclusions

CrII did not produce any signs of toxicity and effectively decreased nociception and inflammation. Also, the anti-inflammatory effect of Crll is at least in part dependent on the integrity of the HO-1 pathway.     

Acaricide activity in vitro of Acmella oleracea against Rhipicephalus microplus

Cattle tick control has been limited by the resistance of these parasites to synthetic acaricides. Natural products are a possible alternative as they have different mechanisms of action. Acmella oleracea is a native plant with a large cultivated area in the Amazon region and could be easily used for large-scale preparation of a commercial product. This study evaluated the in vitro action of the hexane extract of the aerial parts of A. oleracea on larvae and engorged females of the cattle tick Rhipicephalus microplus. Spilanthol was the major constituent with a content of 14.8 % in the extract. The hexane extract of A. oleracea was highly effective against larvae of R. microplus with an LC₅₀ of 0.8 mg mL^?1. Against engorged females, hexane extract of A. oleracea reduced oviposition and hatchability of eggs with an LC₅₀ of 79.7 mg mL^?1. Larvae and engorged females were killed by the hexane extract with high efficiency (>95 %) at concentrations of 3.1 and 150.0 mg mL^?1, respectively. These results demonstrate that the hexane extract of A. oleracea has significant activity against R. microplus and has potential to be developed into formulations for tick control.     

Bone marrow cells migrate to the heart and skeletal muscle and participate in tissue repair after Trypanosoma cruzi infection in mice

Infection by Trypanosoma cruzi, the aetiological agent of Chagas disease, causes an intense inflammatory reaction in several tissues, including the myocardium. We have previously shown that transplantation of bone marrow cells (BMC) ameliorates the myocarditis in a mouse model of chronic Chagas disease. We investigated the participation of BMC in lesion repair in the heart and skeletal muscle, caused by T. cruzi infection in mice. Infection with a myotropic T. cruzi strain induced an increase in the percentage of stem cells and monocytes in the peripheral blood, as well as in gene expression of chemokines SDF‐1, MCP1, 2, and 3 in the heart and skeletal muscle. To investigate the fate of BMC within the damaged tissue, chimeric mice were generated by syngeneic transplantation of green fluorescent protein (GFP⁺) BMC into lethally irradiated mice and infected with Trypanosoma cruzi. Migration of GFP⁺ BMC to the heart and skeletal muscle was observed during and after the acute phase of infection. GFP⁺ cardiomyocytes and endothelial cells were present in heart sections of chimeric chagasic mice. GFP⁺ myofibres were observed in the skeletal muscle of chimeric mice at different time points following infection. In conclusion, BMC migrate and contribute to the formation of new resident cells in the heart and skeletal muscle, which can be detected both during the acute and the chronic phase of infection. These findings reinforce the role of BMC in tissue regeneration.     

Peripheral osteoma bilateral of the mandible without association with Gardner syndrome

Periosteal osteoma is a rare benign pathologic lesion in the jaws and the mandible is the anatomic region most frequently involved. Elective treatment consists of surgical excision. The aim of this report was to report a rare case of bilateral periosteal osteoma involving the mandible--a painless, firm, and well-circumscribed lesion, with more bony prominence on the left than on the right side. The patient had no history of facial trauma or systemic changes that could intervene with the progression of the lesion. It was diagnosed as a periosteal osteoma, and surgical excision was performed. No recurrence after 4 years of follow-up was demonstrated. Surgical excision of the periosteal osteoma was demonstrated to be a useful technical strategy that simplifies and accelerates the surgical procedures and probably contributes to establish harmony of the jaws. Periodical clinical and radiographic follow-ups after surgery are advised.     

The severity of dental caries in adults aged 35 to 44 years residing in the metropolitan area of a large city in Brazil: a cross-sectional study

Background

In recent decades, studies in the field of public health have increasingly focused on social determinants that affect the health-illness process. The epidemiological perspective considers oral health to be a reflection of socioeconomic and environmental aspects, and it is particularly influenced by the social context. The aim of the present study was to assess the association between the severity of dental caries among adults aged 35 to 44 years and characteristics on the different levels at which the determinants of caries operate (individual, social structure and social context).

Methods

A home-based, cross-sectional field study was carried out involving a sample of 1,150 adults (35 to 44 years of age) residing in metropolitan Belo Horizonte, Brazil. The DMFT (decayed, missing, filled tooth) index (≥14) was used to determine the severity of dental caries. Bivariate and multivariate analyses were carried out using the Poisson regression model with the level of significance set at 5% (p < 0.05) and 95% confidence intervals.

Results

The majority of the participants (68.5%) had high caries severity. The rate of high-severity caries in the group between 40 and 44 years of age was 1.15-fold (CI: 1.04-1.26) greater than that among those aged 35 to 39 years. A greater prevalence of high caries severity was found among those who frequently visited the dentist (PR = 1.18; CI: 1.07-1.30), those with a lower income (PR = 1.11; CI: 1.01-1.23), those who reported that their neighborhood did not come together in the previous year to petition political leaders for benefits (PR = 1.16; CI: 1.05-1.28) and those who are unable to make decisions (without empowerment) (PR = 1.12; CI: 1.01-1.24).

Conclusions

The present study revealed high dental caries severity in adults, which was associated with individual characteristics, health-related behavior and social structure and contextual variables. These findings underscore the importance of considering social determinants involved in the health-illness process when carrying out epidemiological studies on dental caries.

     

Caspase-3/caspase-8, bax and bcl2 in pulps of human primary teeth with physiological root resorption

OBJECTIVE. Physiological root resorption is a programmed event that takes place in primary teeth leading to elimination of all root structures. The mechanism behind pulp elimination indicates apoptosis, but its pathway has not been well characterised yet. To better understand this event, we evaluated the gene expression of bax, bcl-2, caspase-3 and caspase-8 through real-time polymerase chain reaction (PCR) and immunohistochemistry expression of Caspase-8 and Bax in pulps. METHODS. Samples were split into two groups: pulps from primary teeth with physiological root resorption (n = 40) and control (n =40), pulps from permanent teeth. Samples of each group were split into PCR (n = 20) and immunohistochemistry (n = 20). RESULTS. Pulps from primary teeth showed a higher caspase-3 mRNA level than pulps from permanent teeth. The expression of bax gene was more intense than caspase-8 but both did not show difference between groups. The bcl-2 mRNA level was incipient and similar between groups. Histopath slides did not show any evidence of inflammatory infiltration, which implies that extrinsic via is not likely to be involved. Immunohistochemistry reaction to Bax and Caspase-8 supported PCR results. CONCLUSIONS. Pulp apoptosis is likely to occur via caspase-3 activation through the mitochondrial pathway.