Summary of current consensus on the effect of smoking on implant therapy

Implant therapy has become a very predictable treatment option in the general population; however, there are certain factors that increase the risk of implant failure. The 2008 National Health Interview Survey estimates that 24.8 million men and 21.1 million women are smokers. The literature regarding cigarette smoking and dental implants currently suggests that advising the patient to stop smoking completely is best, but if this approach is not tenable, then the patient should be warned of the increased risk of implant failure and postoperative complications.     

Feasibility of cervical intramedullary diffuse glioma resection using intraoperative magnetic resonance imaging

Intraoperative magnetic resonance imaging (iopMRI) actually has an important role in the surgery of brain tumors, especially gliomas and pituitary adenomas. The aim of our work was to describe the advantages and drawbacks of this tool for the surgical treatment of cervical intramedullary gliomas. We describe two explicative cases including the setup, positioning, and the complete workflow of the surgical approach with intraoperative imaging. Even if the configuration of iopMRI equipment was originally designed for cranial surgery, we have demonstrated the feasibility of cervical intramedullary glioma resection with the aid of high-field iopMRI. This tool was extremely useful to evaluate the extent of tumor removal and to obtain a higher resection rate, but still need some enhancement in the configuration of the headrest coil and surgical table to allow better patient positioning.     

Enamel white spot lesions can remineralise using bio-active glass and polyacrylic acid-modified bio-active glass powders

Objective

To evaluate the potential of bio-active glass (BAG) powder and BAG containing polyacrylic acid (PAA-BAG) to remineralise enamel white spot lesions (WSL).

Methods

32 human enamel samples with artificial WSLs were assigned to 4 experimental groups (n = 8); (a) BAG slurry, (b) PAA-BAG slurry, (c) “standardised” remineralisation solution (positive control) and (d) de-ionised water (negative control). Mechanical properties of enamel were assessed using surface and cross-section Knoop microhardness. Micro-Raman spectroscopy in StreamLine™ scan mode was used to scan lesion cross-sections. The intensity of the Raman phosphate peak at 959 cm⁻¹ was fitted and measured producing depth profiles analysed using a double-step fitting function. A further 20 samples (n = 5) were used to obtain 3D images of surfaces using non-contact white light profilometry permitting measurement of lesion step height in relation to the sound enamel reference level, and to scan the lesion surface using scanning electron microscopy (SEM). Data were analysed statistically using one-way ANOVA with Tukey's HSD post-hoc tests.

Results

BAG, PAA-BAG and the remineralisation solution exhibited statistically significantly higher surface and cross-section Knoop microhardness compared to the negative control. Micro-Raman spectroscopy detected significantly higher phosphate content within the treated groups compared to the negative control group. Lesions’ depth was not significantly reduced. SEM images revealed mineral depositions, with different sizes and shapes, within BAG, PAA-BAG and the positive control groups.

Conclusion

BAG and PAA-BAG surface treatments enhance enamel WSL remineralisation, assessed by the resultant improved mechanical properties, higher phosphate content and morphological changes within the artificial lesions.     

Basic metabolism: proteins

Proteins serve a range of physiological functions in health and in disease. Their overall structure is determined predominantly by the sequence of amino acids when they are synthesized, which in turn is a derivative of the sequence of nucleotides in the corresponding segment of DNA. There is a constant turnover of body protein, the rate of which exceeds dietary protein intake and therefore suggests a degree of recycling. Some amino acids that enter the body protein pool can be synthesized (‘non-essential’ amino acids) while others can only be obtained through dietary means (‘essential’ amino acids). During critical illness and significant trauma there appears to be dysregulation such that synthesis of some non-essential amino acids is limited, while there is an increase in amino acid oxidation. Modification of dietary intake to address the potential imbalance in illness is probably insufficient in isolation to prevent muscle wasting.