[Attention should be paid to the treatment of traumatic pancreatitis].

Traumatic pancreatitis(TP) is an acute non-infectious inflammation secondary to pancreatic injury.TP can be masked by analgesia or other organ damage after pancreatic injury. So it is difficult to diagnosis in the early stage, easy to missed and misdiagnosis, subsequently prone to infection of pancreatic necrosis (IPN).At present, the treatment of TP is advocated as a step-by-step treatment strategy, which takes minimally invasive surgery as the guidance and takes into account of the principles of multiple injury treatment, inflammation control, infection and necrosis clearance, which runs through the two important links of pancreatic injury and IPN management.

The dehydration effect on mechanical properties of tooth enamel.

Exploring the subtle mechanical property changes of tooth enamel in different conditions is important for dental research. However, some experimental results can be deceptive and may lead to misunderstanding. In particular, we show the dehydration associated with increased mechanical properties of tooth enamel as monitored by Nanomechanical System Testing (NST) can be misleading. The results indicate that the friction coefficient decreased with an increase of hardness of enamel upon dehydration, which appears to imply that dehydrated enamel has better mechanical properties than hydrated enamel. However, more critical scrutiny of the actual situation, suggests dehydrated teeth enamel are more prone to damage and greater wear. To appreciate the basis for the contrast between the experimental results and reality of natural hydrated enamel, which has better resistance to wear, and is critical for an understanding of the aetiology of enamel resistance to fracture.

Factorial analysis of variables influencing mechanical characteristics of a post used to restore a root filled premolar using the finite element stress analysis combined with the Taguchi method.

AIMS: To identify the contributions of various mechanical factors related to cast posts in a root filled tooth by integration of finite element analysis and the Taguchi method. The investigated factors included post-length (Post-L), post-diameter (Post-D), ferrule height (Ferrule-H) and periodontal bone loss (Bone-H). METHODOLOGY: Three-dimensional finite element models of a mandibular premolar were developed to simulate a root filled tooth. For each investigated factor, three levels and values were selected, and based on a Taguchi orthogonal array, nine models were established. An inclination load of 100 N was applied on the buccal cusp tip, and the dentine peak von Mises stress was used as the evaluation index. RESULTS: Among the four investigated factors, Bone-H was the predominant mechanical factor, with a contribution of more than 97%. Among the other three controllable factors of post-design, Post-D was the primary contributing factor and was almost five times more substantial than the least contributing factor, Ferrule-H. CONCLUSION: Bone-H was the predominant factor influencing the stress of the dentine on a post-restored root filled tooth, followed by the Post-D, Post-L and Ferrule-H. For patients with severe periodontal bone loss, a large post-diameter is essential for endodontic post-restoration treatment.

Horizontal and vertical resistance strength of infrazygomatic mini-implants.

This study assessed the adequacy of anchorage strength of infrazygomatic mini-implants in vertical and horizontal directions. Each brand of infrazygomatic mini-implant tested provided acceptable skeletal anchorage.

Thickness vibrations of a piezoelectric plate under biasing fields.

Thickness vibrations of a piezoelectric plate under uniform initial thermoelectromechanical fields are investigated in this article. An exact solution is obtained for materials with general anisotropy. A plate of langasite, a relatively new piezoelectric material with strong piezoelectric coupling, is analyzed with imposed uniform acceleration as the biasing field as an example. The results show that the biasing fields have remarkable effect on the free vibrations of piezoelectric plate.