BACKGROUND Multiple risk factors have been identified for traumatic dental injuries, including crown fractures, in various age groups and various populations. The objective of this study was to determine the prevalence, risk factors and family related factors for crown trauma among 8 to 16 year-old children in a suburban population, Nigeria. METHODS This is a secondary analysis of a data of 2...

CAD/CAM technology in dentistry offers high-end ceramic restorations, known for its quality, preciseness, swiftness and repeatability. However, some features are still human-dependent. A young female patient required smile enhancement, since suffering from colour change on three devitalized frontal teeth. After fiber post placement, teeth were prepared for metal-free restoration. Consequently, ...

We present observations of a long-lived solar filament cavity with soft X-ray sources along its axis. This structure appeared above the southern polar crown polarity-inversion line for approximately three rotations during 1997 June–August, centered at a west-limb passage on approximately July 3. At the limb, the Yohkoh soft Xray data showed a bright region situated above and around the projecte...

Dental trauma can lead to a wide range of injuries of which crown and root fractures are examples. Crown-root fractures often need complex treatment planning. This case report describes the use of MTA in the multidisciplinary management of a patient with a horizontally fractured central incisor and luxation in a different central incisor. A 42-year-old female patient presented within 1 h of rec...

2,4-dithiouracil (DTU) forms in the crystals the H-bonded monohydrates of a 1:1:1 ratio with 18-crown-6 (18C6) 1, cis,syn,cis-isomer of dicyclohexano-18-crown-6 (DCH6A) 2, and benzo-18-crown-6 (B18C6) 3, while the anhydrous adduct with cis,anti,cis-isomer of dicyclohexano-18-crown-6 (DCH6B) 4 is of a 2:1 ratio. In 1-3 the components reproducibly alternate in the chains, while in 4 the chains ar...

Theoretical and experimental investigations indicate that at high loads such as 3/4 throttling or more speeds 3000 rpm more, the exhaust gas temperatures of Internal Combustion engines are about 900-1000 K. The amount heat wasted with is equivalent to power them. By considering this feature engines, a Hybrid engine consisting an (IC) gamma type Stirling was proposed analyzed from thermodynamic ...

Crown profile models were developed for north, east, south, and west crown directions of dominant trees, intermediate trees, and suppressed trees in planted stands of Larix olgensis Henry in Northeast China. A total of 139 sample trees were randomly selected, and all branches of each tree were measured. A segmented power equation, segmented polynomial equation, modified Weibull equation, and Ko...

Supramolecular cations formed by monoprotonated pyridazinium cations and cis-anti-cis-dicyclohexano[18]-crown-6 (DCH[18]-crown-6) or dibenzo[18]-crown-6 (DB[18]-crown-6) were introduced into [Ni(dmit)2]− salts (where dmit2− = 2-thione-1,3-dithiole-4,5-dithiolate). X-ray crystal structure analysis of (pyridazinium+)(DCH[18]-crown-6)[Ni(dmit)2]− (1) revealed a chair-type conformation of the DCH[1...

The synthesis and cation-binding properties of a series of Calixarene derivatives possessing alkyl chain groups, ester groups and crown ether rings have been investigated. The syntheses of Calix[4]arene crown ethers and Calix[6]arene derivatives possessing alkyl chain, ester group and crown ether ring have been described. In order to evaluate their monovalent cation binding abilities, solvent e...

Abrasion of dental crown and the shape of denture occlusal surface are significant indicators in age determination of domestic mammals. The factors that significantly influence age determination of Eneolithic deer game in conditions of an open wildlife habitat are climatic changes that influenced their survival, as well as specific features of teeth morphological structure. In this paper the ag...