Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA 19140, USA.
Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA 19122, USA.
Biomater Adv. 2025 Jan;166:214049. doi: 10.1016/j.bioadv.2024.214049. Epub 2024 Sep 26.
Predicting how tooth and dental material bonds perform in the mouth requires a deep understanding of degrading factors. Yet, this understanding is incomplete, leading to significant uncertainties in designing and evaluating new dental adhesives. The durability of dental bonding interfaces in the oral microenvironment is compromised by bacterial acids, salivary enzymes, and masticatory fatigue. These factors degrade the bond between dental resins and tooth surfaces, making the strength of these bonds difficult to predict. Traditionally studied separately, a combined kinetic analysis of these interactions could enhance our understanding and improvement of dental adhesive durability. To address this issue, we developed and validated an original model to evaluate the bond strength of dental restorations using realistic environments that consider the different mechanical, chemical, and biological degradative challenges working simultaneously: bacteria, salivary esterases, and cyclic loading. We herein describe a comprehensive investigation on dissociating the factors that degrade the bond strength of dental restorations. Our results showed that cariogenic bacteria are the number one factor contributing to the degradation of the bonded interface, followed by cyclic loading and salivary esterases. When tested in combinatorial mode, negative and positive synergies towards the degradation of the interface were observed. Masticatory loads (i.e., cycling loading) enhanced the lactic acid bacterial production and the area occupied by the biofilm at the bonding interface, resulting in more damage at the interface and a reduction of 73 % in bond strength compared to no-degraded samples. Salivary enzymes also produced bond degradation caused by changes in the chemical composition of the resin/adhesive. However, the degradation rates are slowed compared to the bacteria and cyclic loading. These results demonstrate that our synergetic model could guide the design of new dental adhesives for biological applications without laborious trial-and-error experimentation.
预测牙齿和牙科材料在口腔中的结合性能需要深入了解降解因素。然而，这种理解并不完整，导致在设计和评估新的牙科胶粘剂时存在很大的不确定性。口腔微环境中的牙齿粘结界面的耐久性受到细菌酸、唾液酶和咀嚼疲劳的影响。这些因素会降解牙科树脂和牙齿表面之间的粘结，使得这些粘结的强度难以预测。这些因素传统上是分开研究的，对这些相互作用进行综合动力学分析可以增强我们对牙科胶粘剂耐久性的理解和改进。为了解决这个问题，我们开发并验证了一种原始模型，该模型使用考虑到不同机械、化学和生物降解挑战同时作用的真实环境来评估牙科修复体的粘结强度：细菌、唾液酯酶和循环加载。我们在此描述了一项全面的研究，旨在分离降解牙科修复体粘结强度的因素。我们的结果表明，致龋细菌是导致粘结界面降解的首要因素，其次是循环加载和唾液酯酶。当以组合模式测试时，观察到对界面降解的负协同和正协同作用。咀嚼负荷（即循环加载）增强了乳酸细菌的产生和粘结界面处生物膜的覆盖面积，导致界面处更多的损伤，并使粘结强度降低了 73%，与未降解的样品相比。唾液酶也会导致树脂/胶粘剂化学成分的变化而产生粘结降解。然而，与细菌和循环加载相比，降解速率较慢。这些结果表明，我们的协同模型可以指导用于生物应用的新型牙科胶粘剂的设计，而无需繁琐的反复试验。
