Bioactive glass has been employed in several medical applications since its inception in 1969. The compositions of these materials have been investigated extensively with emphasis on glass network formers, therapeutic transition metals, and glass network modifiers. Through these experiments, several commercial and experimental compositions have been developed with varying chemical durability, induced physiological responses, and hydroxyapatite forming abilities. In many of these studies, the concentrations of each alkali and alkaline earth element have been altered to monitor changes in structure and biological response. This review aims to discuss the impact of each alkali and alkaline earth element on the structure, processing, and biological effects of bioactive glass. We explore critical questions regarding these elements from both a glass science and biological perspective. Should elements with little biological impact be included? Are alkali free bioactive glasses more promising for greater biological responses? Does this mixed alkali effect show increased degradation rates and should it be employed for optimized dissolution? Each of these questions along with others are evaluated comprehensively and discussed in the final section where guidance for compositional design is provided.

中文翻译：

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碱金属和碱土元素 (ALAE) 对生物活性玻璃的结构、加工和生物效应的尚未探索的作用

自 1969 年问世以来，生物活性玻璃已被用于多种医疗应用。这些材料的成分已得到广泛研究，重点是玻璃网络形成剂、治疗性过渡金属和玻璃网络改性剂。通过这些实验，已经开发出几种具有不同化学耐久性、诱导生理反应和羟基磷灰石形成能力的商业和实验组合物。在许多此类研究中，每种碱金属和碱土元素的浓度都已改变，以监测结构和生物反应的变化。本综述旨在讨论每种碱金属和碱土金属元素对生物活性玻璃的结构、加工和生物效应的影响。我们从玻璃科学和生物学的角度探讨有关这些元素的关键问题。是否应该包括生物影响很小的元素？无碱生物活性玻璃是否更有希望实现更大的生物反应？这种混合碱效应是否显示出降解率增加？是否应该采用它来优化溶解？这些问题中的每一个以及其他问题都将在最后部分进行全面评估和讨论，其中提供了组合设计的指导。