||Titanium bone plates and screws are commonly used in oral and maxillofacial surgery for internal fixation. Although titanium plate is good for fixation of bone fractures, there are still somemany disadvantages of the material. Biodegradable materials are considered to be good alternatives for treatment of the facial bone fractures.|
Poor wound healing in diabetic animals and human was well known.
The aims of the studies were to compare the strength and tissue reaction of the poly lactic-co-glycolic acid （PLGA） with titanium plates used as fixation material in fractured-femora of diabetic and normal animals.
The results of the studies show that the wounds of the control group healed quite well and there was no discharge around the wound. However, bullas formation was found in all the diabetic wounds fixed with PLGA. There was fistula with pus and gas discharge around the bullas. In the control group, the diameter of the PLGA-fixed femur was larger than the titanium-fixed femura. There was a large amount of callus formation around the PLGA-fixed fracture femur.
At the 20th day, the defects of both groups of the PLGA treated were not healed. A large amount of new bone formation in normal titanium-treated rats was found, while in diabetic rats, mainly a fibrous tissue reaction.
At the 40th day, the diabetic PLGA-fixed femora were poorly healed with a large amount of fibrous tissue. Similarly, after 40 days in the titanium-fixed femora of diabetic rats, extensive fibrosis of the defect was also present. In normal PLGA-fixed fractured femora, there was a large amount of cartilage present around the defect. Most of the normal PLGA-fixed fractured femora were distorted in shape.
At the 40th day, lamellar bone formation was found around the screw in normal titanium-fixed femora and the defect was healed.
In conclusion, the PLGA plate is not suitable for fixation in the fractured-femora of the rats in either normal or diabetic groups when compared with those from titanium plate treat groups. It is because of less strength of the PLGA plate and the material easily cause tissue reaction in the rat which result in the formation of large amount of fibrous tissue around the PLGA screw instead of bone.