A pilot study on dental implant with n-HA/PA66

Objective: To explore a new alloy substitute material for dental implant, a pilot study in dogs was taken with composite of nano-hydroxyapatite and polyamide (n-HA/PA).

Methods: A new biomedical composite material with nano-hydroxyapatite (n-HA 60wt%) and polyamide (PA66 40wt%) was prepared and formed to root-like dental implant based on the dogs' anterior teeth root shape and length. 5 adult dogs with anterior teeth extracted and implanted the root-like implant immediately were used in this study, and the biomedical effects were observed by X-ray and histopathological examination at 4, 8,12,16,20 weeks after operation.

Result: The bending modulus of n-HA/PA66 composite material was 5.5 GPa. 10 root-like n-HA/PA66 implant in 5 dogs were obtained good stability and one implant loosed in one dogs. The same dense of the root on X-ray film were observed with the n-HA/PA66 composite root and the natural root. And there were no significant difference observed on the X-ray film for the space of periodontal with the n-HA/PA66 composite root and the natural root. Good biocompatibility were observed between the alveolar bone and the n-HA/PA66 root by histopathological examination at 4,8,12,16,20 weeks after operation. And the vertical array of the fibers were observed at the periodontal space at 16 week and 20 week.

Conclusion: The bending modulus of n-HA/PA66 composite material is close to the natural alveolar bone. An interesting finding, periodontal space between the alveolar bone and the composite implant was observed by this pilot study. It is necessary to do series studies to evaluate the ability of repairing teeth with composite of nano-hydroxyapatite and polymide, and the feasibility use it as the titanium substitute material for dental implant.

Acknowledgments:The financial support from the project numbered 2007CB936103 by the Ministry of Science and Technology of China is gratefully acknowledged.