The main objective of Project 8, Structure/Properties of Altered Forms of Dentin and Cementum, is to determine specific material """"""""signatures"""""""" for key variations and alterations of dentin and cementum in both primary (deciduous) and permanent teeth. The material """"""""signature"""""""" will be defined by characteristic microstructures, composition and selected properties (mechanical and demineralization) for each form or variation of dental hard tissue. We hypothesize that the """"""""signatures"""""""" will provide a unique identifier for each alteration. These """"""""signatures"""""""" should prove instrumental for developing improved clinical approaches to preventive and conservative, restorative dentistry. We will carry out this work in an ordered, repeated measures design involving a variety of advanced methods including x-ray tomographic microscopy (XTM), atomic force microscopy (AFM) for imaging, demineralization and nanoindentation measurements, small angle x-ray scattering (SAXS) and other standard tools, allowing determination of characteristics of mineral, and collagen fibril structure, repeat distances and cross-links.
Aim 1 will define the """"""""signature"""""""" for transparent dentin associated with coronal caries and attrition in primary and permanent dentin; sclerotic cervical lesions, endodontically treated teeth, and aging of the root. It will also evaluate the mineral level, structure and nanomechanical properties variations of the zones in active and arrested root caries, and identify unique characteristics of dentin associated with Dentinogenesis Imperfecta (DI-II).
Aim 2 will focus on changes associated with collagen cross-link patterns and fibril structure for each variation.
Aim 3 evaluates the """"""""signature"""""""" of secondary and tertiary dentin in primary and permanent teeth, and evaluates the dependence of tertiary dentin """"""""signature"""""""" on the nature of the stimulus.
Aim 4 will determine the age-dependent key components of the """"""""signature"""""""" i.e., structure and properties of cellular and acellular cementum, the cementun-dentin junction (CDJ), and the cementun-enamel junction (CEJ) using the same approach and generally the same teeth as those used for dentin. The """"""""signatures"""""""" from this project will provide fundamental information that will be used to develop a model in Project II, understand the substrate for bonding in Project III and will serve as a baseline for comparison with the """"""""signatures"""""""" of mouse teeth in Project IV.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Program Projects (P01)
Project #
2P01DE009859-11A1
Application #
6534897
Study Section
Special Emphasis Panel (ZDE1-PW (03))
Project Start
1991-08-01
Project End
2007-01-31
Budget Start
1991-08-01
Budget End
2007-01-31
Support Year
11
Fiscal Year
2002
Total Cost
$173,958
Indirect Cost
Name
University of California San Francisco
Department
Type
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Brauer, Delia S; Hilton, Joan F; Marshall, Grayson W et al. (2011) Nano- and micromechanical properties of dentine: Investigation of differences with tooth side. J Biomech 44:1626-9
Brauer, Delia S; Marshall, Grayson W; Marshall, Sally J (2010) Variations in human DEJ scallop size with tooth type. J Dent 38:597-601
Chang, Jolie L; Brauer, Delia S; Johnson, Jacob et al. (2010) Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-? and Runx2 in bone is required for hearing. EMBO Rep 11:765-71
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Ho, Sunita P; Senkyrikova, Pavla; Marshall, Grayson W et al. (2009) Structure, chemical composition and mechanical properties of coronal cementum in human deciduous molars. Dent Mater 25:1195-204
Staninec, Michal; Nguyen, Harrison; Kim, Paul et al. (2008) Four-point bending evaluation of dentin-composite interfaces with various stresses. Med Oral Patol Oral Cir Bucal 13:E81-4
Balooch, M; Habelitz, S; Kinney, J H et al. (2008) Mechanical properties of mineralized collagen fibrils as influenced by demineralization. J Struct Biol 162:404-10
Hsu, Kuang-Wei; Marshall, Sally J; Pinzon, Lilliam M et al. (2008) SEM evaluation of resin-carious dentin interfaces formed by two dentin adhesive systems. Dent Mater 24:880-7
Koester, Kurt J; Ager 3rd, Joel W; Ritchie, Robert O (2008) The effect of aging on crack-growth resistance and toughening mechanisms in human dentin. Biomaterials 29:1318-28

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