Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics.

Objective: To evaluate and compare "in vitro" the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu) and one type of sapphire monocrystalline bracket (Radiance) in dry and artificial saliva wet settings. Also, to evaluate the influence exerted by artificial saliva on the friction forces of those brackets.

Methods: Tests were performed in dry and artificial saliva wet setting (Oral Balance) by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.

The effect of the Ginkgo biloba extract in the expression of Bax, Bcl-2 and bone mineral content of Wistar rats with glucocorticoid-induced osteoporosis.

Objective: Evaluate the effects of the extract of Ginkgo biloba (EGb) in the glucocorticoid-induced-osteoporosis through the Bax and Bcl-2 expressions by osteoblast cells, the x-ray and bone density of the tibia.

Method: Rats were divided into five groups: osteoporosis; EGb1 (28 mg/kg); EGb2 (56 mg/kg); alendronate (0.2 mg/animal) and control.

A reliable positioning device for dorsoventral cephalometric radiography of the rat.

In dental research, dorsoventral cephalometric radiography is often used to assess skull growth and dental movement in rat models. To ensure that images can be reproduced, radiographers must use a cephalostat to maintain the rat's head in a consistent position across imaging sessions. The authors describe a positioning device they designed that connects easily to a standard dental X-ray machine.

Temporomandibular joint alterations after correction of a unilateral posterior crossbite in a mixed-dentition patient: a computed tomography study.

This article discusses the adaptive alterations of the temporomandibular joints of a boy, aged 8 years 5 months, who underwent correction of a unilateral posterior crossbite. The shape and position of the articular structures, imaged by helicoidal computed tomography at the end of the expansion period and 7 months after treatment, showed a tendency toward condylar centralization and articular symmetry.

Computed tomography evaluation of temporomandibular joint alterations in patients with class II division 1 subdivision malocclusions: condyle-fossa relationship.

Thirty persons with Class II Division 1 subdivision malocclusions, ranging in age from 12 years 8 months to 42 years, underwent computed tomography of the temporomandibular joints. The images obtained from sagittal slices were used to assess the depth of the mandibular fossa, the angulation of the posterior wall of the articular tubercle, the condyle-fossa relationship, and the concentric position of the condyles associated with this malocclusion. Paired Student t tests were applied, and Pearson product moment correlations (r) were determined after measurements on both Class I and Class II sides were obtained.