An algorithm to track laboratory zebrafish shoals.

In this paper, a semi-automatic multi-object tracking method to track a group of unmarked zebrafish is proposed. This method can handle partial occlusion cases, maintaining the correct identity of each individual. For every object, we extracted a set of geometric features to be used in the two main stages of the algorithm.

Stress distribution of an internal connection implant prostheses set: a 3D finite element analysis.

Objective: This study evaluated the stress distribution by loads, under a internal connection implant system with two sort of abutment screws and prosthetic crown models at ten observation points.

Materials And Method: The analysis were made in two models with internal butt joint, and with gold and titanium screw, respectively. The load was 382N with 90 masculine to the occlusal surface and 15 masculine to the implant axis at 4 and 6 mm from the implant center.

The influence of the Nd:YAG laser bleaching on physical and mechanical properties of the dental enamel.

Background And Objectives: The Nd:YAG laser can be used in Dentistry to remove soft tissue, disinfect canals in endodontic procedures and prevent caries. However, there is no protocol for Nd:YAG laser application in dental bleaching. The aims of this in vitro study were: (a) to observe the tooth shade alteration when hydrogen peroxide whitening procedures are associated with dyes with different wavelengths and irradiated with Nd:YAG laser or halogen light; (b) to measure the Vickers (VHN) enamel microhardness before and after the whitening procedure; (c) to evaluate the tensile bond strength of two types of adhesive systems applied on bleached enamel; (d) to observe the failure pattern after bond strength testing; (e) to evaluate the pulpal temperature during the bleaching procedures with halogen light or laser; (f) to measure the kinetic reaction of hydrogen peroxide.

Creating three-dimensional tooth models from tomographic images.

Unlabelled: The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur.

Development of a device to measure bracket debonding force in vivo.

The purposes of this study were to develop a device to measure bracket debonding force in vivo and to evaluate, in vitro, the bond strength obtained with the device and with tensile and shear bond strength (SBS) tests performed in a universal testing machine. The device was developed using polypropylene pliers (3M Unitek). The basic principle consisted of measuring the applied force to debond, using two strain gauges (Kyowa) bonded to the region of major deformation of the plier handles.