Flexural Strength of an Indirect Composite Modified with Single-Wall Carbon Nanotubes

OBJECTIVES

 The low resistance to fracture has limited the use of indirect composite resins for dental restorations, particularly in regions that are exposed to strong occlusal forces. To overcome this issue, different types of reinforcement for composites have been proposed, one of which is carbon nanotubes (CNTs). The aim of this study was to evaluate the flexural resistance of one commercial indirect composite resin (Sinfony, 3M/ESPE) after incorporation of single-wall carbon nanotubes (SWCNTs; Sigma-Aldrich, Inc., St. Louis, Missouri, United States) with or without the silanization form.

MATERIALS AND METHODS

 Specimens of composite resin were fabricated in a Teflon mold. The composite resin was prepared according to the manufacturer's instructions (n = 10 for each group), with SWCNTs in three concentrations.

STATISTICAL ANALYSIS

 The SWCNTs and SWCNT/SiO2-ATES specimens were evaluated by transmission electron microscopy, and a flexural test was conducted according to the ISO 4049/2009. Flexural strength data in MPa were submitted to one-way ANOVA following Tukey (p < 0.05).

RESULTS

 The SWCNTs did not improve the flexural strength of indirect composite resin when compared with the control, independent of the concentration added (p > 0.05). However, when SWCNTs and SWCNTs/SiO2-ATES were compared, the SWCNTs/SiO2-ATES showed higher values than the three concentrations of SWCNTs (p < 0.05).

CONCLUSION

 The silanization process improves the SWCNTs strength proprieties, but the modification of chemical bonding between SWCNT and SWCNT/SiO2-ATES modified resins, in different concentrations, did not improve the composite resin flexural strength.

Association of salivary alpha-2-macroglobulin with glycemia and glycated hemoglobin in type 2 diabetes mellitus: a systematic review and meta-analysis study

BACKGROUND

Chronically elevated alpha-2-macroglobulin (A2MG) in the blood has been correlated with diabetes and the HbA1c profile; however, no systematic review has been conducted to evaluate the association of A2MG salivary levels and glycemia or HbA1c levels in diabetes mellitus type 2 (DM2) patients.

OBJECTIVE

To evaluate whether A2MG salivary levels are related to the glycemia or HbA1c levels in DM2 patients.

DESIGN AND SETTING

Systematic review developed at Universidade Federal de Uberlândia (UFU), Brazil.

METHODS

Eight databases were used as research sources. The eligibility criteria included studies that reported data regarding mean salivary A2MG and the correlation between glycemia and/or HbA1c levels of DM2 subjects (uncontrolled and well-controlled) and non-diabetic subjects. The risk of bias of the studies selected was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools for use in JBI systematic reviews. Pooled correlation coefficients were estimated using the Hunter-Schmidt method. Study estimates were weighted according to their sample size, and heterogeneity was calculated using the chi-square statistic.

RESULTS

Four studies on DM2 patients were included in this systematic review after careful analysis of 1482 studies. Three studies compared A2MG with HbA1c and glycemia. Overall, the correlation between A2MG and HbA1c was strong (r = 0.838). In contrast, the correlation between A2MG and glycemia was low (r = 0.354).

CONCLUSION

The strong association between HbA1C and salivary A2MG suggests that this salivary protein has the potential to be a surrogate for HbA1C, if corroboratory further evidence is obtained through large-scale studies.

Alternative Method for Full Oral Rehabilitation in Patients with Pycnodysostosis Syndrome: A Case Report

Pycnodysostosis (PYCD) is a rare autosomal recessive skeletal dysplasia arising from a change in the production of the cathepsin K enzyme and it is also known as Maroteaux-Lamy Syndrome. The main changes in the buccal and maxillofacial region are modifications of the facial bones (leading to the loss of the mandibular angle due to micrognathia), deep palate, premature and/or delayed tooth eruption, hypopneumatization of the maxillary sinuses, chin hypoplasia, hypercementosis, enamel hypoplasia, hyperdontia, incomplete dentin calcification, root hypoplasia, pulp chamber obliteration, and increased free functional space. This paper aims to report a case of a patient with PYCD, in which are highlighted the oral manifestations of this syndrome and present an option of oral rehabilitative treatment through a removable overdenture made on natural tooth of the patient. The technique of dental coating through overdenture is a simple, viable and conservative alternative for oral rehabilitation of patients with large maxillomandibular discrepancies, as in cases of pycnodysostosis, especially in the presence of increased free space - characteristic of patients with this syndrome. The result was quite satisfactory both aesthetically and functionally and provided a better life quality for the patient.

The quality of life of family health professionals: a systematic review and meta-synthesis

ABSTRACT Objectives: to perform a systematic review and meta-synthesis of qualitative studies about the work-related quality of life of Family Health Strategy professionals. Methods: this systematic review was developed to answer the following PVO question: “Which factors (variables) are associated with the work-related quality of life (outcome) of Family Health Strategy professionals (population)?” The PubMed, Scopus, Embase, SciELO, Web of Science, LILACS, Science Direct, OpenThesis, OpenGrey, and OATD databases were selected. The meta-synthesis analyzed the main codes and secondary codes of all included studies. Results: the database search resulted in 1,744 reports; six were considered eligible for the meta-synthesis. Four factors were considered for the quality of work life: working conditions; work processes; interpersonal relationships; and personal aspects. Conclusions: although this study confirms the adequacy of aspects commonly related to the quality of work life, other factors are important in the case of FHS professionals, especially work context.