Hamoudi Walid K, Shakir Zinah S, Ismail Raid A, Al-Jumaily Hassanien A, Sahib Shama Anees, Abedulwahhab Abdullah R
Al-Farabi University College, Department of Optics Techniques, Baghdad, Iraq.
University of Technology, Department of Applied Science, Baghdad, Iraq.
J Lasers Med Sci. 2021 Dec 26;12:e82. doi: 10.34172/jlms.2021.82. eCollection 2021.
Dental decay is caused by the fermentation of carbohydrates and the production of acids which demineralize teeth. The fermented food debris lowers the pH under 5.5, resulting in the mineral loss of teeth. Anti-decay factors are used to reduce decay rates and increase dental protection. Fifteen sectioned teeth samples were immersed in Ag NPs solution and then irradiated with laser pulses. Structures, morphologies, chemical compositions and microhardness were studied using the Vickers micro-hardness tester, energy dispersive x-ray machine, atomic force microscope and scanning electron microscopes. Nine mature extracted human third molars, cleaned and placed in plastic molds then filled with a warm epoxy resin, were sectioned longitudinally and polished. The samples were then cleaned ultrasonically and stored in distilled water and taken immediately one by one for laser treatment. Sharper, overlapping, interconnected rods and higher resistance against enamel decay were demonstrated with little alterations of the mineral percentages of the teeth samples. The combination of laser light and silver annoparticles improved the decay resistance; where regular inter-connected chain-like merged grains were formed. These laser-induced modifications in enamel components have reduced the lattice stress and enamel solubility and improved resistance against decay. The computer model indicated a possible prediction of the laser-treated profile prior to laser treatment.
龋齿是由碳水化合物发酵以及产生使牙齿脱矿的酸所引起的。发酵后的食物残渣会使pH值降至5.5以下，导致牙齿矿物质流失。防龋因子用于降低龋齿发生率并增强牙齿保护。将15个切片牙齿样本浸入银纳米颗粒溶液中，然后用激光脉冲照射。使用维氏显微硬度测试仪、能量色散X射线仪、原子力显微镜和扫描电子显微镜研究其结构、形态、化学成分和显微硬度。9颗成熟拔除的人类第三磨牙，清洗后放入塑料模具中，然后用温热的环氧树脂填充，纵向切片并抛光。然后将样本进行超声清洗，保存在蒸馏水中，并逐一立即取出进行激光处理。结果表明，牙齿样本的矿物质百分比变化不大，但出现了更尖锐、重叠、相互连接的棒状物，且对牙釉质龋的抵抗力增强。激光与银纳米颗粒的结合提高了抗龋能力；形成了规则的相互连接的链状合并颗粒。这些激光诱导的牙釉质成分改变降低了晶格应力和牙釉质溶解度，提高了抗龋能力。计算机模型表明，在激光治疗之前可能对激光治疗后的轮廓进行预测。
