Degradation
Polymer chain cleavage, enzymatic action or metallic corrosion changes the material. It need not immediately disappear.
THE SCIENCE
The material lifetime must match the medical task.
Degradation, absorption and functional performance are related, but they are not interchangeable measurements.
DIFFERENT PROCESSES
Functional life
Strength, stiffness, barrier properties or electronic performance can change well before full resorption.
Resorption
Biological processing, incorporation or clearance of degradation products must be characterized for the specific system.
What affects the timeline?
Molecular weight, crystallinity, composition, surface area, geometry, hydration, local pH, loading and tissue environment all influence material change. Materials do not carry a universally reliable resorption date independent of their design.
Some devices use several materials with different lifetimes, requiring component-level as well as system-level evaluation.
What needs measurement?
Relevant tests include mechanical-property retention, mass loss, molecular-weight evolution, corrosion behavior, degradation-product characterization, local tissue response and performance under intended conditions.
ISO 10993-1:2025 places biological evaluation within a risk-management process, rather than treating biocompatibility as an intrinsic material label.
DIRECT ANSWERS
Questions worth asking.
Is biodegradation the same as bioresorption?
No. Biodegradation is material breakdown; bioresorption additionally concerns the fate and clearance or incorporation of the breakdown products in a biological system.
Does an implant disappear once it loses strength?
Not necessarily. Molecular-weight decline and loss of function may precede major mass loss or full resorption.