[Bone density and biomechanics study of alveolar ridge augmentation with titanium nickel shape memory alloy distractor and acellular dermal matrix].

Objective: To observe the dynamic changes of bone density and bone strength after alveolar ridge augmentation with Titanium Nickel shake memory alloy (TiNi-SMA) distractor and acellular dermal matrix (ADM).

Methods: Twelve adult healthy male dogs were selected. After the animal model of alveolar atrophy was set up, on one side of mandible, two S-shaped distractors were placed. The diameter of S-shaped distractor was 1 mm and the rebound temperature was 33 degrees C. The ADM was placed on the distraction gap and fixed by the feet of distractors. The other side was placed only with distractors, serving as control side. Six dogs' mandibles were harvested after 1 and 3 months respectively. Dual energy X-ray absorptiometry (DEXA) was used to scan bone density around the distraction gap. Mechanical machine was used to test compression strength and elastic modulus.

Results: Months after distraction, the bone density of upper distraction gap, distraction gap and low distraction gap were respectively (0.714 +/- 0.238) g/cm2, (0.512 +/- 0.435) g/cm2 and (0.615 +/- 0.043) g/cm2 on experimental side. The compression strength and elastic modulus were (36.54 +/- 7.32) MPa and (1674.10 +/- 256.43) MPa. All of above were higher than those of control side.

Conclusions: ADM can improve the bone quality, increase bone density and intensity and is an ideal guided bone regeneration(GBR) membrane for alveolar ridge augmentation with TiNi-SMA distractor.