In vivo Dentin Microhardness beneath a Calcium-Phosphate Cement

A minimally invasive caries-removal technique preserves potentially repairable, caries-affected dentin. Mineral-releasing cements may promote remineralization of soft residual dentin. This study evaluated the in vivo remineralization capacity of resin-based calcium-phosphate cement (Ca-PO4) used for indirect pulp-capping. Permanent carious and sound teeth indicated for extraction were excavated and restored either with or without the Ca-PO4 base (control), followed by adhesive restoration. Study teeth were extracted after 3 months, followed by sectioning and in vitro microhardness analysis of the cavity floor to 115-µm depth. Caries-affected dentin that received acid conditioning prior to Ca-PO4 basing showed significantly increased Knoop hardness near the cavity floor. The non-etched group presented results similar to those of the non-treated group. Acid etching prior to cement application increased microhardness of residual dentin near the interface after 3 months in situ

The impact of social isolation on the health status and health-related quality of life of older people

Purpose: To investigate for socially isolated older people, and older people at risk of social isolation: (1) health status and health-related quality of life (HRQL); (2) the relationship between social isolation and health status/HRQL; (3) the relationship between two alternative measures of health status/HRQL. Methods: Older people at risk of social isolation (n = 393) completed the EQ-5D and the SF-12. Multiple regression analyses were performed to examine the relationship between levels of social isolation and health status/HRQL, controlling for demographic/clinical characteristics. The agreement between EQ-5D and SF-6D (SF-12) scores was explored using descriptive psychometric techniques. Results: Health status and health state values were much lower than UK general population age-matched norms. After controlling for depression, physical co-morbidities, age, gender, living alone status, employment and accommodation, social isolation was significantly associated, to a degree that was clinically relevant, with EQ-5D DSI, SF-6D (SF-12) and SF-12 MCS scores. The potential for ceiling effects on the EQ-5D with this population was identified. Conclusion: This work highlights the burden that social isolation may have on the health and well-being of older people. The potential HRQL gains from addressing social isolation may be considerable, with those at risk of social isolation also a key target group

In vivo Acid Etching Effect on Bacteria within Caries-Affected Dentin

Acid etching procedures may disrupt residual bacteria and contribute to the success of incomplete caries removal followed by adhesive restoration. This study evaluated the in vivo effect of acid etching on cariogenic bacterial activity within affected dentin after minimally invasive treatment of caries lesions. Twenty-eight carious permanent teeth received standardized selective caries removal and random acid etch treatment (E) or not (NE) prior to adhesive restoration. Baseline and 3-month dentin biopsies were collected. The number of bacteria and activity of total bacterial cells and Streptococcus mutans were determined by quantitative PCR and RT-PCR. No statistically significant differences were observed in total bacterial number and activity between E and NE treatments (p > 0.3008). For NE, however, the residual S. mutans bacterial cells were reduced (p = 0.0027), while the activity per cell was significantly increased (p = 0.0010) after reentry at 3 months after restoration. This effect was not observed in group E. Although no significant differences were found between groups, this study suggests that acid etching of affected dentin prior to adhesive restoration may directly or indirectly have an inhibitive effect on the activity of residual cariogenic bacteria. Further research is required to investigate this potential effect

Moldes de ABS construídos pelo processo de modelagem por fusão e deposição para injeção de PP e PEBD PP and LDPE injection in ABS molds built with fused deposition modeling

Os processos de prototipagem rápida (Rapid Prototyping - RP) e ferramental rápido (Rapid Tooling - RT) surgiram para reduzir os tempos de desenvolvimento de produtos na fase de projeto diminuindo a necessidade de retrabalhos e, conseqüentemente, antecipando a entrada de novos produtos no mercado. Neste trabalho foi utilizada uma das tecnologias de prototipagem rápida, denominada Modelagem por Fusão e Deposição (FDM), na construção de moldes em ABS com o objetivo de investigar sua aplicação na moldagem por injeção de termoplásticos. Amostras das peças injetadas foram submetidas a ensaios de difração de raios X, dureza Shore D e tração. Os resultados mostraram a viabilidade de fabricar pequenos lotes de peças em PEBD e PP com propriedades mecânicas bastante similares às encontradas em peças moldadas em moldes metálicos.<br>Rapid Prototyping and Rapid Tooling are aimed at reducing the development time of products in the design phase by minimizing re-workings and, consequently, reducing the time to launch new products. In this work one of the technologies of rapid prototyping, called Fused Deposition Modeling (FDM), was used in the construction of ABS molds with the objective of investigating its application in the injection molding of thermoplastics. Specimens of the molded parts were characterized with X-ray diffraction, Shore D hardness and tensile tests. The results demonstrated the viability to manufacture small batches of LDPE and PP parts with mechanical properties similar to those molded parts in metallic molds

Detection of C-polysaccharide in serum of patients with Streptococcus pneumoniae bacteraemia.

AIM--To investigate the fate of Streptococcus pneumoniae C-polysaccharide antigen in serum in patients with S pneumoniae bacteraemia. METHOD--In vitro dissociation experiments were performed to demonstrate that C-polysaccharide was masked by ligands in normal and acute phase serum. Serum samples from 22 patients with S pneumoniae bacteraemia were treated to dissociate immune complexes and then tested for C-polysaccharide by enzyme linked immunosorbent assay (ELISA). RESULTS--C-polysaccharide antigen was masked in normal and acute phase serum but could be released by EDTA treatment and detected by ELISA. Antigen was found in six patients ranging in concentration from 2.5 to 200 ng/ml. Patients with detectable antigen were more likely to die than those in whom antigen was not detected. CONCLUSION--This study demonstrates that C-polysaccharide antigen commonly circulates in patients with S pneumoniae bacteraemia but its presence is masked by ligands present in serum