Bone Abstracts

Objectives: The study is aimed at analysis of ultrastructure of biomineral of the ramus of mandible after implantation of manganese enhanced hydroxylapatite into the tibia.

Methods: The study involved 252 male rats. The 1st group comprised intact animals, the 2nd group – animals with 2.2 mm defect in the tibia, and the groups 3 through 6 – the animals with the defects filled with hydroxylapatite enhanced with 0.0, 0.1, 0.25, and 0.5% share of manganese. Biomineral of the ramus of mandible were prepared for X-ray scattering analysis.

Results: Fracture modeling (2.2 mm defect in tibia shaft) leads to instability of ultrastructure of biomineral of the ramus of mandible (enlargement of elementary cells and crystallites, and microtexture coefficient decrease) up to the 90 day of observation. Implantation of pure hydroxylapatite into defect also affects stability of crystal lattice of biomineral of the ramus of mandible; alterations are observed from the 15th to the 30th days of observation and after that crystal lattice began to restore. Manganese enhanced implants significantly reduce negative effects of fracture on instability of ultrastructure of biomineral of the ramus of mandible; the most effective were the implants with 0.25% of manganese. With manganese concentration increase up to 0.25% microtexture coefficient from the 15th to the 60th day was higher than those of the 3rd group by 5.62, 4.19 and 3.70%, and sizes of crystallytes from the 30th to the 180th day were lower than those of the 3rd group by 4.95, 6.14, 6.26 and 3.75% respectively (from here and on, all numeric values are significant with P<0.05). Implants with 0.5% of manganese cause manganese intoxication observed as decrease of microtexture coefficient from the 60th to the 180th days of observation with intensity peak at the 90th day of observation (microtexture coefficient decreased from the 60th to the 180th day as compared to the control values of the 3rd group by 3.30, 4.86 and 3.74% respectively).

Conclusions: Application of manganese enhanced implants significantly reduces negative effects of ultrastructure of the biomineral of the ramus of mandible. Implants with 0.25% share of manganese proved to be the most effective while implants with 0.5% share of manganese produced signs of manganese intoxication.