Effect of bioresorbable fibres (Polyfibre®) and a bioresorbable foam (Polyfoam®) on new bone formation: A short term experimental study on the rabbit skull

Abstract

The aim of the study was to evaluate two bioresorbable polylactic acid (PLA) filler materials in a guided bone regeneration (GBR) model system. The first was Polyfibre®, a fibrous PLA filler material. Polyfoam®, the second material tested, consisted of a spongy PLA filler material. In each group there were eight rabbits. In test rabbits a flap was raised uncovering the calvaria. A hemispherical PLA dome was filled with Polyfibre® or Polyfoam® material and periphereal blood and anchored onto the calvaria. Eight rabbits with the same domes, filled with blood alone, served as controls. The rabbits were sacrificed at 1 or 2 months. Histomorphometric measurements of regenerated total tissue volume, bone height and bone volume were carried out in undecalcified sections under a light microscope. At 1 month the totally filled volume attained 87% (range 82-91) in the fibre group, including 25% (23-27) fibres, 87% (85-95) in the foam group, including 15% (15-16) foam, and 55% (16-100) in the controls. The volume of mineralized bone was 12% (7-15) in the fibre group, 15% (12-18) in the foam group and 6% (1-11) in control domes. Bone height attained 48% (27-79) in the fibre group, 37% (31-58) in the foam group and 45% (14-67) in the control group. At 2 months, tissue volume attained 86% (85-87) including 26% (22-29) fibres, bone volume attained 13% (7-21) and bone height attained 56% (42-78) in the Polyfibre® group. In the Polyfoam® group, they were 83% (55-99) including 18% (15-19) foam, 13% (7-24) and 49% (29-74). In control domes, tissue volume was 82% (35-100), bone volume 20% (9-27) and bone height 86% (60-100). The Polyfibre® and Polyfoam® material was excellently integrated. No adverse reactions were found in the surrounding tissues. Direct bone apposition was observed onto the material. In conclusion, Polyfibre® and Polyfoam® material had a positive effect on initial bone and tissue formation but was a hindrance to increasing tissue volume, bone volume or bone height at 2 months compared to control specimens. The Polyfibre® and Polyfoam® material provoked no adverse reactions in the surrounding tissues and allowed for extensive angiogenesis.