Composite resin restorative materials have become the primary choice in dentistry due to their ability to produce tooth-colored restorations with favorable mechanical properties. However, several challenges remain, including polymerization shrinkage, micro-leakage, and bacterial retention, which may lead to secondary caries. Research in dental materials continues to address these limitations by modifying resin compositions and filler materials. One recent innovation conducted by an FKG UGM student, Dwi Aji Nugroho, under the supervision of Prof. Dr. drg. Widjijono, S.U.; Prof. Dr. rer. nat. Nuryono, M.S.; and Prof. drh. Widya Asmara, S.U., Ph.D., involves the utilization of nanofibers as filler materials in composite resin. In the cited study, nano sisal fiber (“nanosisal”) was used as an alternative filler to enhance the mechanical and microbiological properties of composite resin.
Characteristics of Nanofibers in Composite Resin
1. Definition and Benefits
Nanofibers in this context refer to particles or fibers at the nanometer scale used as fillers within a resin matrix. Nanofillers offer several advantages:
- Their extremely small particle size enables more uniform distribution within the resin matrix, reducing the distance between filler particles and optimizing matrix–filler interactions.
- A larger surface area per unit mass of filler provides greater adhesion area and more effective coupling agent interaction.
- With nanofiber fillers, polymerization shrinkage is expected to be minimized, water and pigment permeability reduced, and resistance to bacterial retention improved.
2. Implementation in “Nanosisal” Research
The cited study developed composite resin using sisal fibers processed to nanoscale size, referred to as “nanosisal.” The study reported:
- Differences in shrinkage volume percentage: nanosisal composite showed shrinkage of approximately 9.407 ± 1.899%, and nanosisal with a coupling agent (diglycidyl ether bisphenol) showed about 7.107 ± 1.742%, compared to conventional nanofiller composite controls (~14.257 ± 0.863%).
- Flexural strength, microhardness, water absorption, and Streptococcus mutans adhesion were also evaluated. Results demonstrated that nanosisal with a coupling agent significantly reduced bacterial adhesion.
These findings indicate that the use of nanofibers as fillers has the potential to improve mechanical performance and reduce microbiological risks in composite resin restorations.
Clinical Considerations
Despite the advantages of nanofiber use in composite resin, several challenges must be considered:
- Filler dispersion and agglomeration: Although nanoscale size is advantageous, nanofillers tend to agglomerate if not properly processed, potentially creating weak points in the material.
- Matrix–filler interaction: Effective coupling agents are required to ensure optimal adhesion between nanofillers and the resin matrix, facilitating mechanical strength and microbiological resistance.
- Long-term stability: The effects of reduced shrinkage and bacterial retention still require long-term testing under real oral conditions, including evaluations of wear, discoloration, and marginal stability.
- Biocompatibility and safety: The use of natural fibers or new nanofillers must undergo safety and clinical feasibility testing before widespread application.
Clinical Implications and Future Prospects
The adoption of composite resin with nanofiber fillers may offer the following clinical benefits:
- Restorations with lower shrinkage → reduced risk of microleakage and secondary caries.
- Smoother and more aesthetic restoration surfaces due to uniform nanoparticle distribution → more natural appearance and improved polishability.
- Potential antimicrobial effects through reduced bacterial retention on modified filler surfaces, contributing to better peri-restorative tissue health.
- Opportunities for more environmentally friendly next-generation restorative materials, particularly when natural fillers such as sisal are used as alternatives to glass-based inorganic fillers.
In the future, integration of nanofibers with digital technologies (CAD/CAM), active nanotechnology (e.g., ion-releasing anti-caries fillers), and long-term clinical research will further establish this material as a new standard in aesthetic restorative dentistry.
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The use of nanofibers in composite resin represents a promising innovation to enhance dental restoration performance, both mechanically and microbiologically. Based on the cited research, nano sisal fillers (“nanosisal”) demonstrate potential in reducing shrinkage, decreasing bacterial retention, and improving flexural strength compared to control materials. Although further research—particularly under real clinical conditions—is still required, this development paves the way toward more durable, aesthetic, and biologically favorable restorations for patients.
References
DWI AJI NUGROHO, Prof. Dr. drg. Widjijono, S.U.; Prof.Dr.rer.nat.Nuryono, M.S.; Prof.drh.Widya Asmara, S.U., Ph.D. , “Pembuatan Material Tumpatan Resin Komposit Dengan Nanosisal sebagai Bahan Pengisi (Filler) (Kajian Mekanis dan Mikrobiologis)”, https://etd.repository.ugm.ac.id/penelitian/detail/177693
Author: Rizky B. Hendrawan | Photo: Freepik
