Vertebrate enamel formation is a unique synthesis of the function of highly specialized enamel proteins and their effect on the growth and organization of apatite crystals. Among tetrapods, the physical structure of enamel is highly conserved, while there is a greater variety of enameloid tooth coverings in fish. In the present study, we postulated that in enamel microstructures of similar orga...

modelling of crack propagation by finite element method under mixed mode conditions is of prime importance in fracture mechanics. this paper describes an application of finite element method to the analysis of mixed mode crack growth in linear elastic fracture mechanics. crack growth process is simulated by an incremental crack-extension analysis based on the maximum principal stress criterion,...

OBJECTIVES HIV prevalence among people who inject drugs (PWID) in Ottawa is estimated at about 10%. The successful integration of peers into outreach efforts and wider access to HIV point-of-care testing (POCT) create opportunities to explore the role of peers in providing HIV testing. The PROUD study, in partnership with Ottawa Public Health (OPH), sought to develop a model for community-based...

OBJECTIVE To examine relationships between parenting behaviors, parent-child relationship, and moderating effects of age on youth substance use among a community sample of African-American mothers who use crack cocaine and their children (12-17 years). METHODS Maternal-child dyads (n = 208) were recruited through street outreach and snowball sampling and completed interviews about substance u...

The mechanical properties of enamel and dentin were studied using test specimens having the same shape and dimensions because these properties might vary with the experimental conditions and specimen shapes and dimensions. Healthy human teeth were used as specimens for mechanical tests. The stress (MPa), strain (%), and elastic modulus (E, MPa) of the specimens were obtained from compression te...

in this paper, the crack detection and depth ratio estimation method are presented in beamlikestructures using elman networks. for this purpose, by using the frequencies of modes asinput, crack depth ratio of each element was detected as output. performance of the proposedmethod was evaluated by using three numerical scenarios of crack for fixed-simply supportedbeam consisting of a single crack...

The form of two hard tissues of the mammalian tooth, dentine and enamel, is the result of a combination of the phylogenetic inheritance of dental traits and the adaptive selection of these traits during evolution. Recent decades have been significant in unveiling developmental processes controlling tooth morphogenesis, dental variation and the origination of dental novelties. The enamel-dentine...

In the field of dentistry, the murine incisor has long been considered as an outstanding model to study amelogenesis. However, it clearly appears that enamel from wild type mouse incisors and molars presents several structural differences. In incisor, exclusively radial enamel is observed. In molars, enamel displays a high level of complexity since the inner part is lamellar whereas the outer e...

Presented here is an unusual case of teeth with aberrant enamel. One small and 3 large enamel pearls were identified in 2 maxillary third molars of a patient. One long enamel projection was connected to one of the large enamel pearls, along with 2 short cervical enamel projections. The ectopic enamel was associated with advanced localized periodontal destruction. After extraction, the molars we...

BACKGROUND Amelogenin is required for normal enamel formation and is the most abundant protein in developing enamel. METHODS Amelx+/+, Amelx+/- , and Amelx-/- molars and incisors from C57BL/6 mice were characterized using RT-PCR, Western blotting, dissecting and light microscopy, immunohistochemistry (IHC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), backscatte...