Introduction and objective:
Polydioxanone (PDO), a biodegradable synthetic polymer, has been proposed for small orbital reconstructions due to its absorbable nature. However, past findings have raised concerns about its inflammatory response, warranting further investigation. The aim of this study is to evaluate the inflammatory profile and behaviour of periorbital tissue in rabbits using a PDO membrane.

Material and methods:
The trial was carried out in 17 male rabbits of the species Oryctolagus Cunilicus, in which one of the orbits was submitted to surgical exposure and positioning a PDO membrane (intervention). In the contralateral orbit, a titanium sheet (TS) was positioned (positive control). The orbits were evaluated to identify the inflammatory profile (neutrophils, plasma cells, lymphocytes, and blood vessels) by histometry at 7, 15, and 60 days.

Results:
The PDO group had more plasma cells in the 7 days than the titanium group (p = 0.012). In the 15 days, the PDO group had a higher number of lymphocytes (p = <.001), neutrophils (p = <.001), and plasma cells (p = <0.004) compared to the titanium group. Analysis of the granulation tissue area revealed a higher mean around the PDO in the periods of 7 and 15 days (p = 0.009 and p = <.001). PDO assessment did not suffer significant changes between the periods, and no remnants of the membrane were observed at 60 days. In contrast, the titanium group showed a significant decrease between 7–15 days (p = 0.041), and no changes between 15–60 days.

Conclusions:
Considering the limitations, it was concluded that the PDO membrane caused a greater inflammatory process than TS, however, this inflammation did not extend to adjacent periorbital tissues or result in relevant clinical changes during post-operative follow-up.