Gingival biopsy is easy to obtain and mostly complete healing takes place with out any complications
Gingival histological features may be correlated with difficult to obtain biopsy i.e. brain,spinal cord, kidney spleen ,eye and other area
The gingival involvement and perhaps biopsy may help in patients with GPA especially is there is strawberry gingivitis
Given the association between periodontitis and systemic diseases, it would seem sensible to use gingival biopsies as a surrogate for more hard-to-reach tissues. However, this relies on the gingivae adequately reflecting/being influenced by systemic health in a way that can be differentiated from systemically healthy individuals. In both cases, systemically healthy or not, the gingival tissues are much more likely to show the condition of the gingivae, with inflammatory infiltrate based on level of gingival inflammation, than the systemic health of the patient.
Hope than answers your question.
Gingival biopsy is also least invasive way to diagnose amyloidosis.