In this study, the elastohydrodynamic lubrication (EHL) behaviour of high-speed spur gear contacts is investigated under dynamic conditions. A non-linear time-varying vibratory model of spur gear pairs is introduced to predict the instantaneous tooth forces under dynamic conditions within both the linear and non-linear operating regimes. In this model, the periodically time-varying gear mesh st...

introduction:temporomandibular disorders (tmds) are referred to signs and symptoms involving masti catory muscles, temporomandibular joint and rele vant structures. having been prevalent noticeably, we decided to evaluate the frequency of tmd, among patients referred to the dental clinic of guilan university of medical sciences. materials and methods: in this cross-sectional study, a sample of ...

background and aims. bruxism is defined as a habitual nonfunctional forceful contact between occlusal tooth surfaces. in younger children bruxism may be a consequence of the masticatory neuromuscular system immaturity. the aim of this study was to assess the prevalence of bruxism and investigate the relationship between occlusal factors and bruxism among preschool children. materials and method...

In recent years, many dental professionals have changed their philosophy regarding the use of trays with at-home bleaching regimens. However, facts do not change--and successful vital tooth bleaching still occurs only when tooth surfaces are in direct contact with the appropriate concentration of active whitening agent for a specific amount of time. Because the science of tooth whitening is sti...

OBJECTIVES this study investigated the effects of growth and tooth loading on the structural adaptation of the developing alveolar bone adjacent to the tooth root as the tooth erupted into function. Growth and occlusal function were expected to lead to increased alveolar bone density. Meanwhile, the supporting alveolar bone was expected to develop a dominant trabecular orientation (anisotropy) ...

The purpose of this study was to validate the elastomeric impression after temporary tooth separation as a method of cavitation detection in proximal caries lesions in primary molars with outer half dentin radiolucency. Fifty-one children (4-10 years old), presenting radiolucency in the outer half of the dentin at the proximal surfaces of primary molars and proximal anatomic contact with the ad...

INTRODUCTION The aims of this study were to evaluate the stability of machined microimplant anchorage after immediate orthodontic loading in dogs and to ascertain clinical and histologic features. METHODS Sixty microimplants were placed in the buccal sides of the maxillae and mandibles of 4 dogs, including the interradicular area. Superelastic nickel-titanium coil springs were activated betwe...

In order to enhance the load capacity of gears, researchers take notice in the asymmetric tooth gears. Asymmetric gear which has higher pressure angle of back tooth aiming to improve banding strength has been analyzed (Deng, et al., 2003). Brown et al. (Brown, et al., 2010) investigate the asymmetric tooth from both point of view of bending and scuffing. Kruger et al. (Kruger et al., 2013) anal...

Abstract This article analyzes the cause of an abnormal defect in oil chromatogram a transformer, and puts forward control measures suggestions. It is analyzed that phase A B main transformer poor contact o f dynamic static contacts unloaded tap changer, high temperature overheatin g, development ablation, resulting chromatogram. The ablation no-load tap-changer may be due to installation trans...