Prepolymerized vs. in situ-polymerized fiber-reinforced composite implants--a pilot study

Area of Science:

• Biomaterials Science
• Orthopedic Research
• Dental Materials

Background:

• Bioactive fiber-reinforced composites (FRC) show promise for bone implants.
• Polymerization methods can influence implant-tissue integration.
• Understanding FRC bone response is crucial for developing effective bone regeneration strategies.

Purpose of the Study:

• To compare bone response to FRC implants polymerized under two different conditions.
• To evaluate the osseointegration of prepolymerized versus in situ-polymerized FRC implants.
• To investigate the effect of polymerization technique on fibrous capsule formation around FRC implants.

Main Methods:

• Cylinder-shaped FRC implants made from glass-fiber-dimethacrylate composite were fabricated.
• Implants were tested in two forms: prepolymerized and polymerized in situ using blue light.
• Ten FRC implants were surgically placed into the tibias of three pigs using a press-fit technique.
• Histological analysis using light microscopy was performed after 12 weeks to assess bone response.

Main Results:

• Both prepolymerized and in situ-polymerized FRC implants elicited only a mild foreign-body reaction with minimal inflammatory cell accumulation.
• Prepolymerized FRC implants demonstrated full integration with the surrounding bone tissue.
• In situ-polymerized FRC implants were largely encapsulated by a fibrous capsule, indicating impaired osseointegration.

Conclusions:

• In situ polymerization of FRC implants leads to the formation of a fibrous capsule.
• This fibrous capsule formation prevents the integration of in situ-polymerized FRC implants with bone.
• Prepolymerization is a critical factor for achieving successful osseointegration of FRC implants.