Role of chitin beads in the formation of jaw bone by guided tissue regeneration

Abstract

It has been reported that local application of bone grafts or synthetic bone substitutes (filler materials) may favour bone formation when used in combination with guided tissue regeneration (GTR). Therefore, the aim of the present investigation was to evaluate the effect of application of chitin beads (a bioabsorbable natural polymer) as a bone substitute in bone formation by GTR. The experiment was carried out in 25 rats. The mandibular ramus was exposed on one side after elevation of a muscle-periosteal flap, and a teflon capsule filled with chitin beads (2.0 mm in diameter) was placed with its opening facing the lateral aspect of the ramus. On the contralateral side of the jaw, serving as control, an empty teflon capsule was placed in the same manner. Groups of 5 animals were sacrificed at 7, 15, 30, 60 and 120 days following capsule placement. Histological analysis demonstrated that the amount of newly formed bone was similar in both experimental and control specimens, amounting to approximately 3% of the central/largest, cross-sectional area created by the capsule at 15 days, and to approximately 9% of this area at 30 days following capsule placement. At 60 and 120 days, however, the amount of newly formed bone observed in the control specimens was twice as large as that observed in the test specimens, amounting to approximately 31% of the cross-sectional area created by the capsule at 60 days, and to approximately 45% at 120 days. It is concluded that, although chitin beads (2.0 mm in diameter) are biocompatible, their presence retards bone formation in the model system used.