Can strontium replace calcium in bioactive materials for dental applications?

Bioactive materials have been widely studied for dental and medical applications due to their ability to interact with biological systems. Calcium is a common component in these materials, but recent interest has shifted to strontium as a potential substitute. However, concerns remain about the stability of strontium-substituted materials and their potential toxicity. Prior research has shown that calcium-based materials can cause elemental deposition in organs like the kidneys. This gap motivated investigations into whether strontium can replace calcium without harmful effects. No prior work had resolved the long-term tissue compatibility of strontium-substituted materials. Understanding the local and systemic effects of these materials is essential for clinical translation. The need for safer alternatives in dental applications has driven this line of inquiry. Researchers aim to confirm whether strontium can serve as a viable replacement without triggering inflammation or toxicity.

This study aimed to assess the feasibility of replacing calcium with strontium in bioactive dental materials. The specific problem addressed was whether strontium substitution affects material stability and tissue compatibility. Researchers developed bioactive materials with partial or full calcium substitution using strontium. The motivation stemmed from the potential benefits of strontium, such as its role in bone metabolism and reduced elemental migration compared to calcium. The study sought to evaluate material degradation and tissue responses over time. Animal models were used to simulate real-world conditions. The goal was to determine if strontium-substituted materials can be safely used in dental applications. The findings could guide the development of safer and more effective bioactive materials.

Researchers synthesized bioactive materials by substituting calcium with strontium in varying proportions. The materials included bioactive glass, hydroxyapatite, and hydraulic calcium silicate. Two substitution levels—50% and 100%—were tested to assess their properties. The set materials were characterized immediately after setting and after 30 and 180 days in solution. Subcutaneous implantation was performed in an animal model to evaluate tissue interactions. Histological analysis was conducted to assess inflammation and angiogenesis. Elemental migration was tracked using mapping techniques in local tissues and peripheral organs. The study focused on material stability, leaching patterns, and long-term biocompatibility.

Strontium substitution resulted in partially substituted phases and leaching at all time points. Over half of the implanted strontium silicate cements could not be retrieved, indicating high material digestion. Inflammation was observed in all materials after 30 days but subsided by 180 days with angiogenesis. Strontium was not detected in local tissues or peripheral organs. Calcium-containing materials caused calcium deposition in the kidneys. Strontium silicate showed elemental migration of calcium and silicon in local tissues but no systemic deposition. The absence of strontium in peripheral organs suggests minimal systemic effects. These findings indicate that strontium substitution is biocompatible and safe for dental applications.

The authors propose that strontium can replace calcium in bioactive materials without adverse effects. The study suggests that strontium substitution does not cause systemic toxicity or persistent inflammation. The absence of strontium in peripheral organs implies low migration risk. The observed angiogenesis after 180 days indicates tissue healing and integration. The material digestion rate suggests good biocompatibility. The findings support the use of strontium-substituted materials in dental applications. The study does not claim strontium is superior to calcium but suggests it is a viable alternative. The authors conclude that strontium substitution may offer a safer option for bioactive materials in clinical settings.