Department of Removable Prosthodontics and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
School of Dentistry, Pitágoras Faculty, Uberlândia, MG, Brazil.
Clin Oral Investig. 2021 Jun;25(6):4059-4068. doi: 10.1007/s00784-020-03736-0. Epub 2021 Mar 25.
To evaluate the effect of ionizing radiation and cariogenic biofilm challenge using two continuous flow models, normal and reduced salivary flow, on the development of initial root-dentin caries lesions.
Microcosm biofilms were grown under two salivary flow rates (0.06 and 0.03 mL min) and exposed to 5% sucrose (3 × daily, 0.25 mL min, 6 min) dripped over non-irradiated and irradiated root-dentin blocks for up to 7 days. The vibration modes of root dentin, matrix/mineral (M/M), and carbonate/mineral (C/M) ratios were evaluated by FTIR. The mineral density was assessed by micro-CT.
With normal salivary flow, FTIR revealed an increase in the organic matrix (amide III) and a decrease in the mineral phase (ν ν PO, AII + ν CO, C/M) in caries lesions. Irradiated dentin exhibited a reduction in the mineral phase (ν, ν PO, ν CO, C/M). Differences in mineral densities were not significant. With reduced salivary flow, FTIR also revealed increased organic matrix (amide III) for irradiated caries lesions and decrease in mineral phase (v v PO, v CO, and C/M) in caries lesions. ν, ν PO precipitated on the surface of irradiated dentin and a lower mineral density was observed.
Initial caries lesions differed between non-irradiated and irradiated dentin and between normal and reduced salivary flow rates. Significant mineral loss with exposure of the organic matrix and low mineral density were observed for irradiated dentin with a reduced salivary flow rate.
Ionizing radiation associated with a reduced salivary flow rate enhanced the progression of root-dentin caries.
使用两种连续流动模型（正常和减少的唾液流率）评估电离辐射和致龋生物膜挑战对初始牙根牙本质龋损发展的影响。
微宇宙生物膜在两种唾液流速（0.06 和 0.03 mL min）下生长，并暴露于 5%蔗糖（每天 3 次，0.25 mL min，6 分钟）滴注在未辐射和辐射的牙根牙本质块上，最长可达 7 天。通过傅里叶变换红外光谱（FTIR）评估牙根牙本质的振动模式、基质/矿物质（M/M）和碳酸盐/矿物质（C/M）比。通过微 CT 评估矿物质密度。
在正常唾液流率下，FTIR 显示龋损中有机基质（酰胺 III）增加，矿物质相（ν ν PO、AII + ν CO、C/M）减少。辐照牙本质的矿物质相减少（ν、ν PO、ν CO、C/M）。矿物质密度的差异不显著。在减少的唾液流率下，FTIR 还显示出辐射龋损的有机基质（酰胺 III）增加，以及龋损中矿物质相（v v PO、v CO 和 C/M）减少。ν 在辐照牙本质表面沉淀，观察到较低的矿物质密度。
未辐照和辐照牙本质以及正常和减少的唾液流速之间的初始龋损不同。在减少的唾液流速下，辐照牙本质的有机基质暴露和矿物质密度降低，导致明显的矿物质损失。
与减少的唾液流速相关的电离辐射增强了牙根牙本质龋的进展。
