Theses
FORENSIC DENTISTRY:
DENTAL INDICATORS FOR IDENTIFICATION A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Master of Arts in The Department of Geography and Anthropology ABSTRACT The use of dentition for identification has been well established in the field of forensics. However, dental analysis has been employed primarily for positive personal identification. The purpose of this thesis research is to explore the possibility of using dental characteristics for general profiling of the decedent. Dental characteristics, including caries and dental restorations, were examined in the dentition of 41 modern forensic cases in the LSU FACES Collection. Twenty-one of these cases are positively identified individuals whose remains were donated to the university. The other 20 cases are active forensic cases which have not been identified. The general profiling information, including sex, age, race, and socioeconomic status, was compared with the dental characteristics to determine any correlations between the categories. In the 20 unidentified cases, socioeconomic status was not known and, therefore, these cases were not analyzed for socioeconomic status correlations. Many significant relationships exist between the dental characteristics and the identifiers, sex, race, age, and socioeconomic status. Socioeconomic status has the least number of correlations. Age and race have the most. download the full thesis Title: EFFECT OF GLASS JOINS ON PERFORMANCE OF LAYERED DENTAL CERAMIC SYSTEMS Authors: Saied, Mey Advisors: Lloyd, Isabel K Lawn, Brian R Department/Program: Material Science and Engineering Type: Dissertation Sponsors: Digital Repository at the University of Maryland University of Maryland (College Park, Md.) Keywords: 0794 Engineering, Materials Science 0541 Engineering, Biomedical 0567 Health Sciences, Dentistry ceramic, dental material, glass, interface toughness, layered structures, lead-free Issue Date: 2008 Abstract: Layered structures can be used to address the competing needs of systems like dental crown restorations where the exterior needs to be aesthetic and the interior needs to be strong and fatigue resistant. Dental crowns typically have an aesthetic porcelain veneer layered on a strong, fatigue resistant ceramic or metallic core. In current restorations, even when the core is shaped by a computer-aided design and manufacturing (CAD/CAM) or solid-freeform fabrication processes, the veneer is applied in sequential layers. This process is labor intensive, time consuming and may not optimize the long-term performance properties of the veneer layer. If the core and veneer layers were to be independently fabricated and then joined, their individual and the veneer-core system performance could be optimized. Some groups have explored the possibility of joining with filled epoxies, which is easier, but may not be long-lasting. In this project we explore the possibility of using more durable glassy joins. Dense, thermal-expansion-matched (to the core and veneer glass) joins can be fired at temperatures far enough below the melting and/or slumping temperatures to join veneers to cores without degradation. In this study, we design and fabricate joining glasses for bonding porcelain veneers to ceramic cores, specifically to dental aluminas and zirconias. We study the chemical bonding and mechanical integrity of the resulting layers. Finally, we assess the effects of glass joins on performance of layered dental ceramic systems. download the full thesis |
do babies take calcium from your teeth
No , babies do not take calcium from Mothers' teeth. There is a popular belief that it may be normal to lose teeth during pregnancy since the fetus draws calcium from its mother's teeth. In fact, the teeth of pregnant women do not decalcify. If the baby needs to find the calcium necessary for its growth, it will draw it from the reserves of the bones of the mother, hence the importance of following the recommendations concerning the daily consumption of calcium for pregnant women (1,300 mg /day).
Pregnancy is a time of upheaval, whether physical changes or changes in lifestyle. All of this can have an impact on dental health. For example, hormones like estrogen and progesterone increase the susceptibility of the gums to plaque buildup. They can also affect the ligaments and bone that support the teeth, which can make them mobile and cause the gums to bleed. In addition, morning sickness during the first trimester and gastric reflux during the third can increase the acidity in the mouth of pregnant women. source: http://www.teeth.baby/2022/11/do-babies-take-calcium-from-your-teeth.html Title: High elastic modulus nanopowder reinforced resin composites for dental applications Authors: Wang, Yijun Advisors: Lloyd, Isabel K. Greer, Sandra C. Department/Program: Material Science and Engineering Type: Dissertation Sponsors: Digital Repository at the University of Maryland University of Maryland (College Park, Md.) Keywords: 0794 Engineering, Materials Science 0567 Health Sciences, Dentistry 0794 Engineering, Materials Science alumina; nanocomposite; nanoindentation; dental crown; elastic modulus Issue Date: 27-Aug-2007 Abstract Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more attention and their popularity has risen because of their superior aesthetics and biocompatibility. However, their relatively high failure rate and labor-intensive fabrication procedure still limit their application. In this thesis, a new family of high elastic modulus nanopowder reinforced resin composites and their mechanical properties are studied. Materials with higher elastic modulus, such as alumina and diamond, are used to replace the routine filler material, silica, in dental resin composites to achieve the desired properties. This class of composites is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Most of the work focuses on nano-sized Al2O3 (average particle size 47 nm) reinforcement in a polymeric matrix with 50:50 Bisphenol A glycidyl methacrylate (Bis-GMA): triethylene glycol dimethacrylate (TEGDMA) monomers. Surfactants, silanizing agents and primers are examined to obtain higher filler levels and enhance the bonding between filler and matrix. Silane agents work best. The elastic modulus of a 57.5 vol% alumina/resin composite is 31.5 GPa compared to current commercial resin composites with elastic modulus <15 GPa. Chemical additives can also effectively raise the hardness to as much as 1.34 GPa. Besides>alumina, diamond/resin composites are studied. An elastic modulus of about 45 GPa is obtained for a 57 vol% diamond/resin composite. Our results indicate that with a generally monodispersed nano-sized high modulus filler, relatively high elastic modulus resin-based composite cements are possible. Time-dependent behavior of our resin composites is also investigated. This is valuable for understanding the behavior of our material and possible fatigue testing in the future. Our results indicate that with effective coupling agents and higher filler loading, viscous flow can be greatly decreased due to the attenuation of mobility of polymer chains. Complementary studies indicate that our resin composites are promising for the proposed applications as a stiff support to all-ceramic crowns. download the full thesis |