The biocompatibility and bond strength between the surfaces of dental restorations are highly influenced by the interaction between the core material (composite resin, ceramic, or metal) with fillers, coatings, and bioactivators that accelerate the formation of interfacial bonds. This article discusses the role of bioactivators in improving the interfacial bond in dental restorations, focusing on bioactivation mechanisms, effects on tissue remineralization, as well as potential antibacterial effects and stability within the oral environment.
This aligns with research conducted by a student of the Faculty of Dentistry, Universitas Gadjah Mada, Alifia Anandiza F, under the supervision of Dr. drg. Tri Endra Untara, M.Kes., Sp.KG(K) and Dr. drg. Wignyo Hadriyanto, M.S., Sp.KG(K), titled “The Role of Bioactive Glass as a Filler in Composite Resin on Remineralization and Antibacterial Properties.” The study emphasized improving interfacial bonds through the formation of bioactive layers on restoration joint surfaces.
Concept of Bioactivators and Their Mechanisms
- Mechanism of bioactive layer formation: the formation of phosphate apatite around the material surface that enhances chemical bonding with dentin tissue.
- Bond stabilization through ion release: the release of ions from bioactivators (e.g., Na⁺, Ca²⁺, SiO₄⁴⁻) can modulate biomineralization at the interface.
- Antibacterial and remineralization effects: bioactivators can reduce the risk of bacterial colonization at restoration joints while enhancing mineralization in the surrounding restoration area.
Methods of Evaluating Biocompatibility and Interfacial Bond
- In vitro studies: testing pulp/dentin cell viability, cell adhesion to surfaces, and analyzing apatite layer formation on the bioactivator material surface.
- Chemical-physical analysis: ion release profiles, changes in crystallinity, and surface oxide stability after finishing treatment.
- Mechanical tests: assessment of bond strength (shear/bond strength) between composite resin and bioactivator-treated surfaces, as well as evaluation of interfacial retention during simulation periods.
- Clinical tests/in vivo expression: evaluation of periodontal and mucosal tissue responses to restorations that use bioactivators.
Expected Results
- Improved interfacial bond strength through surface reconditioning and formation of bioactive layers that add chemical and mechanical adhesion.
- Remineralization of dentin tissue around restoration joints, enhancing structural strength and resistance to microbial corrosion.
- Antibacterial effects that reduce biofilm formation at the interface, thereby lowering the risk of secondary caries and restorative failure.
- Long-term stability of restoration joints against the dynamically acidic-alkaline oral environment.
Factors Affecting Bioactivator Effectiveness
- Type of bioactivator and composition: variations of bioactive glass, silica, or combinations of other bioactivators influence the speed and quality of apatite layer formation.
- Ion release level: maintaining a balance of ion release sufficient for remineralization without causing tissue irritation.
- Interaction with resin matrix: compatibility between bioactivator and resin matrix affects distribution, adhesion, and bond strength.
- Surface condition before application: smooth finishing is required to facilitate uniform bioactive layer formation.
Clinical Implications
Proper selection of bioactivators can improve restoration longevity through stronger interfacial bonds and remineralization around joints, thereby reducing cracks and damage caused by the oral environment.
References
Alifia Anandiza F, Dr. drg. Tri Endra Untara, M.Kes., Sp.KG(K); Dr. drg. Wignyo Hadriyanto, M.S., Sp. KG(K), The Role of Bioactive Glass as a Filler in Resin Composites on Remineralization and Antibacterial Effects, https://etd.repository.ugm.ac.id/penelitian/detail/218755
Author: Rizky B. Hendrawan | Photo: Freepik
