The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Brian R. Lawn - One of the best experts on this subject based on the ideXlab platform.
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role of multiple cusps in Tooth Fracture
Journal of The Mechanical Behavior of Biomedical Materials, 2014Co-Authors: Amir Barani, Mark Bush, Brian R. LawnAbstract:The role of multiple cusps in the biomechanics of human molar Tooth Fracture is analysed. A model with four cusps at the bite surface replaces the single dome structure used in previous simulations. Extended finite element modelling, with provision to embed longitudinal cracks into the enamel walls, enables full analysis of crack propagation from initial extension to final failure. The cracks propagate longitudinally around the enamel side walls from starter cracks placed either at the top surface (radial cracks) or from the Tooth base (margin cracks). A feature of the crack evolution is its stability, meaning that extension occurs steadily with increasing applied force. Predictions from the model are validated by comparison with experimental data from earlier publications, in which crack development was followed in situ during occlusal loading of extracted human molars. The results show substantial increase in critical forces to produce longitudinal Fractures with number of cuspal contacts, indicating a capacity for an individual Tooth to spread the load during mastication. It is argued that explicit critical force equations derived in previous studies remain valid, at the least as a means for comparing the capacity for teeth of different dimensions to sustain high bite forces.
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Fracture of Tooth enamel from incipient microstructural defects
Journal of the Mechanical Behavior of Biomedical Materials, 2010Co-Authors: Herzl Chai, J. J W Lee, Brian R. LawnAbstract:We present definitive evidence for crack growth from internal defects called 'tufts' in human enamel. Transverse slices (normal to the Tooth axis) sawn from extracted human teeth are embedded in a polycarbonate sandwich configuration and tested in simple flexural loading. The evolution of ensuing cracks across the enamel sections is viewed in situ by a video camera. The observations unequivocally identify tufts as sources of internal Tooth Fracture. In sufficiently thin slices the enamel becomes translucent, allowing for through-thickness observations of the crack topography. Crack segments that appear to be disjointed on a section surface link up into a contiguous primary crack below the surface, suggesting some crack resistance by 'bridging' behind the advancing crack tip. The role of these and other microstructural factors in determining the resilience of Tooth structures is considered.
D Arola - One of the best experts on this subject based on the ideXlab platform.
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on the mechanics of fatigue and Fracture in teeth
Applied Mechanics Reviews, 2014Co-Authors: Mobin Yahyazadehfar, Juliana Ivancik, Hessam Majd, Dongsheng Zhang, D ArolaAbstract:Tooth Fracture is a major concern in the field of restorative dentistry. However, knowledge of the causes for Tooth Fracture has developed from contributions that are largely based within the field of mechanics. The present manuscript presents a technical review of advances in understanding the Fracture of teeth and the fatigue and Fracture behavior of their hard tissues (i.e., dentin and enamel). The importance of evaluating the Fracture resistance of these materials, and the role of applied mechanics in developing this knowledge will be reviewed. In addition, the complex microstructures of Tooth tissues, their roles in resisting Tooth Fracture, and the importance of hydration and aging on the Fracture resistance of Tooth tissues will be discussed. Studies in this area are essential for increasing the success of current treatments in dentistry, as well as in facilitating the development of novel bio-inspired restorative materials for the future.
Sahar F Albarakati - One of the best experts on this subject based on the ideXlab platform.
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elementary school staff knowledge about management of traumatic dental injuries
Clinical Cosmetic and Investigational Dentistry, 2018Co-Authors: Fares S Alsehaibany, Danah Z Almubarak, Reem Alajlan, Mohammad A Aldosari, Nasser D Alqahtani, Nassr Almaflehi, Sahar F AlbarakatiAbstract:Aim This study investigated the knowledge of elementary school staff regarding the management of traumatic dental injuries (TDIs) in children. Methods The present cross-sectional study analyzed data collected between September 2016 and April 2017. The sample consisted of 2,027 elementary school staff members in Riyadh, Saudi Arabia. A stratified cluster random sampling technique was used to select the required sample. Those who agreed to participate in the study completed a 4-part self-administered questionnaire comprising questions regarding demographic data, knowledge on management of Tooth Fracture, and avulsion using photographs of TDI cases. Results The majority of the school staff showed inadequate basic knowledge regarding the importance of saving the broken piece of the Tooth and identifying the Tooth involved in the trauma (67% and 66.3%, respectively), P<0.05. However, they had a significantly high number of correct responses regarding the immediate management of TDIs for the 2 case scenarios presented in the questionnaire (P<0.05), and the majority (41%) reported normal saline as a suitable storage medium (P<0.01). Conclusion This study revealed a lack of knowledge in certain aspects of TDIs among elementary school staff.
Blaire Van Valkenburgh - One of the best experts on this subject based on the ideXlab platform.
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naturally occurring Tooth wear Tooth Fracture and cranial injuries in large carnivores from zambia
PeerJ, 2021Co-Authors: Blaire Van Valkenburgh, Paula A WhiteAbstract:Determining the incidence and causes of craniodental damage in wild carnivores is often constrained by limited access to specimens with associated ecological data, such as prey type and abundance. We assessed dental condition and cranial injuries in lion, leopard, and spotted hyena in relation to prey and predator populations in Zambia's Luangwa Valley, where large prey are more abundant and lion and leopard more numerous, and the Greater Kafue Ecosystem, where smaller prey species are more prevalent and lion and leopard less common. In Luangwa, lions had significantly higher rates of Tooth Fracture, and blunt trauma injuries attributable to prey-handling, compared to Kafue lions. In contrast, leopards in both regions had similar rates of Tooth wear and breakage. Overall, lions showed a significantly higher Tooth Fracture rate than leopards on a per Tooth basis. Spotted hyenas had the highest rates of Tooth wear and Fracture among all three carnivores, and greatly exceeded previously recorded rates based on historical samples. Despite larger numbers of lion and leopard in Luangwa, there was no difference in incidence of intraspecific injuries between regions. These results are consistent with a greater abundance of large prey species, especially buffalo, in the diets of Luangwa lions, and previous work showing a reliance on smaller prey species in Kafue throughout the large carnivore guild.
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Costs of carnivory: Tooth Fracture in Pleistocene and Recent carnivorans
Biological Journal of the Linnean Society, 2008Co-Authors: Blaire Van ValkenburghAbstract:Large, carnivorous mammals often break their teeth, probably as a result of Tooth to bone contact that occurs when carcasses are consumed more fully, a behaviour likely to occur under conditions of food stress. Recent studies of Pleistocene predators revealed high numbers of teeth broken in life, suggesting that carcass utilization and, consequently, food competition was more intense in the past than at present. However, the putative association between diet and Tooth Fracture frequency was based on a small sample of large, highly carnivorous species. In the present study, a greater diversity of extant carnivorans is sampled, including insectivorous, omnivorous, and carnivorous forms, ranging in size from weasels to tigers. Species that habitually consume hard foods (bones, shells) had the highest Fracture frequencies, followed by carnivores, and then insectivorous and/or omnivorous species. Predator and prey sizes were not associated with Tooth Fracture frequency, but more aggressive species did break their teeth more often. Comparison of the modern sample with five Pleistocene species confirms the previous finding of higher Tooth breakage in the past, although some extant species have Fracture frequencies that approach those of extinct species. Thus, the Pleistocene predator guild appears to have been characterized by relatively high levels of competition that are rarely observed today. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 68‐81.
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temporal variation in Tooth Fracture among rancho la brea dire wolves
Journal of Vertebrate Paleontology, 2002Co-Authors: Wendy J Binder, Elicia N Thompson, Blaire Van ValkenburghAbstract:ABSTRACT Canis dirus preserved in the late Pleistocene Rancho La Brea tar seep deposits display a remarkably high incidence of teeth broken in life as compared with modern species. This might reflect greater carcass utilization in the Pleistocene relative to the present. Here we compare Tooth Fracture frequencies in C. dirus between two localities at Rancho La Brea, Pit 13 (about 15 ka) and Pit 61/67 (about 12 ka). Results indicate that Pit 13 C. dirus exhibited heavier Tooth wear and Fractured their teeth about three times more often than those of the younger Pit 61/67. This might reflect a difference in diet between the two periods or a greater preservation of older individuals (which are more likely to have broken teeth) in Pit 13. To test for differences in the mortality profiles of the two pits, we estimated individual age C. dirus from pulp cavity dimensions of lower canine teeth, as measured from radiographs of preserved mandibles. We first verified the validity of the approach using a sample of ex...
James D Bader - One of the best experts on this subject based on the ideXlab platform.
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Risk indicators for posterior Tooth Fracture.
Journal of the American Dental Association (1939), 2004Co-Authors: James D Bader, Daniel A Shugars, Jean A MartinAbstract:ABSTRACT Background Identifying posterior teeth that are at heightened risk of developing cusp Fracture is an inexact science. Risk indicators based on controlled observations are not available, and dentists' assessments vary. Methods The authors conducted a case-control study of cusp Fracture in restored posterior teeth. They evaluated 39 potential risk indicators identified in previous uncontrolled studies for an association with Fracture in 200 patients with Fractures and 252 patients without Fractures. These risk indicators delineated patients' clinical characteristics and behaviors, as well as clinical characteristics of individual teeth. The authors used logistic regression to develop models identifying risk indicators associated with Fracture, both between case and control subjects and between case and comparison teeth in case subjects. Results Two risk indicators appeared in both models. The presence of a Fracture line and an increase in the proportion of the volume of the natural Tooth crown occupied by the restoration substantially increased the odds of Fracture ( P Conclusions Among posterior teeth with restorations, two clinical features were strongly associated with the risk of cusp Fracture: presence of a Fracture line in the enamel and proportional volume of the restoration. Clinical Implications Dentists assessing the risk of Fracture should consider a detectable Fracture line or a high ratio of restoration-to-total-crown volume as important indicators of elevated risk.
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using crowns to prevent Tooth Fracture
Community Dentistry and Oral Epidemiology, 1996Co-Authors: James D Bader, Daniel A Shugars, T M RobersonAbstract:Placing crowns to prevent Tooth Fracture is thought to be a common but infrequently documented treatment procedure. Two studies are described that provide information about dentists' use of crowns to prevent Tooth Fracture. North Carolina general dentists indicated that 44% of the crowns they placed were for the principal reason of Fracture prevention. However, when groups of dentists examined the same patients, there was little agreement about which teeth should be crowned due to risk of Fracture. These results suggest that the placing of crowns to prevent Fracture merits a careful determination of effectiveness and appropriateness.
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preliminary estimates of the incidence and consequences of Tooth Fracture
Journal of the American Dental Association, 1995Co-Authors: James D Bader, Jean A Martin, Daniel A ShugarsAbstract:The authors studied all Tooth Fractures identified within a two-week period among adult enrollees in a dental health maintenance organization to determine the incidence and severity of this condition. They found complete Fracture rates of 5.0 and 4.4 per 100 adults per year for all teeth and for posterior teeth, respectively, with 15 percent of Fractures resulting in pulpal involvement or extraction. These estimates, the first to be reported, provide information that is potentially useful to patients and dentists making decisions about treatment intended to prevent Tooth Fracture.
