Investigation of the bone tissue response to glass-ionomer microimplants in the canine maxillary alveolar ridge.

This paper reports the results of experimental use of glass-ionomer microimplants in the augmentation of the maxillary alveolar ridge in dogs. The study included ten adult mongrel dogs 5 years of age, weighing between 50 and 70 pounds (25-30 kg), divided into 2 groups of 5 dogs each. In both groups, the maxillary 4th premolar and 1st molar were removed after the elevation of a buccal mucoperiosteal flap. The alveolar bone adjacent to the extracted teeth was also removed. In the experimental group (5 dogs), Ionogran a glass-ionomer microimplants (GIMIs) (Ionogran particle size of 0.5-1.0 mm, IONOS Medizinische Produkte GmbH & Co. KG, D-8031 Seefeld, Gemany) were used for augmentation and were inserted in the created defects. The extraction sockets and bone defects were augmented with an average amount of 2 g of GIMIs. In the control group, the bone defects were left unfilled as a control for bone healing. Histological examination showed that the glass-ionomer microimplants were extremely osteoconductive and inert materials. Stimulation of growth of new bone tissue in contact with the glass-ionomer microimplants was evident. No inflammatory cells were detected on or adjacent to the GIMIs. In the control group, incomplete bone healing with fibrous scar tissue and inflammatory cells was noted. These results indicate that glass-ionomer microimplants represent highly osteoconductive and biocompatible materials for use in bone surgery.