Angker Linny, Nockolds Clive, Swain Michael V, Kilpatrick Nicky
Biomaterials Science Research Unit, Faculty of Dentistry, University of Sydney, United Dental Hospital, 2 Chalmers Street, Surry Hills, NSW 2010 Sydney, Australia.
Arch Oral Biol. 2004 May;49(5):369-78. doi: 10.1016/j.archoralbio.2003.12.005.
The deterioration of the mechanical properties of carious dentine was assumed to be associated with the decrease in mineral content due to the carious process. This study aimed to compare the mechanical properties of carious dentine studied by an ultra-micro-indentation-system (UMIS) and the mineral content determined using backscattered scanning electron (BSE) imaging. Eight axial sectioned and fine polished primary molar teeth with untreated carious dentine were measured for hardness and elastic modulus using the UMIS. On each specimen two centrally located linear arrays of indentations were made from the pulp to lesion cavity floor, followed by the capture of a BSE image using a solid-state detector. The BSE intensity at the same spot as the indentation array on each specimen was analysed and compared to the UMIS results. The results show that the mechanical properties of dentine are dependent on its mineral content. The decrease in mechanical properties of carious dentine, namely hardness and elastic modulus are directly linked to the reduction in its mineral content (r2 = 0.93 and 0.92, respectively). The relationship between dentine hardness and elastic modulus values (y) can be expressed as an exponential function of the mineral content in wt.% (x) that is y = ae(bx).
龋损牙本质力学性能的恶化被认为与龋病过程中矿物质含量的降低有关。本研究旨在比较用超微压痕系统（UMIS）研究的龋损牙本质的力学性能和使用背散射扫描电子（BSE）成像测定的矿物质含量。使用UMIS对八颗带有未经治疗的龋损牙本质的轴向切片并精细抛光的乳磨牙进行硬度和弹性模量测量。在每个标本上，从牙髓到病变腔底部制作两个位于中心的线性压痕阵列，然后使用固态探测器采集BSE图像。分析每个标本上与压痕阵列相同位置的BSE强度，并与UMIS结果进行比较。结果表明，牙本质的力学性能取决于其矿物质含量。龋损牙本质力学性能的降低，即硬度和弹性模量，与矿物质含量的减少直接相关（r2分别为0.93和0.92）。牙本质硬度和弹性模量值（y）之间的关系可以表示为矿物质含量（重量百分比，x）的指数函数，即y = ae(bx)。
