Abstract: Objective To evaluate the quantity of new bone formation through maxillary sinus bone augmentation using space maintaining device and to assess the influence of perforation on it.Methods Space maintaining devices were made by pure titanium to keep the elevated space.Three adult male beagle dogs were subjected to extraction of the third premolar and all molars of both sides to create a model with bone volume deficiency in the maxillary posterior region.After the natural healing 3 months later,space maintaining devices were installed simultaneously with the elevation of maxillary sinus membrane using the lateral approach without the use of bone substitutes.A perforation of 2 mm in diameter was randomly created in one side.Three animals were sacrificed 3 months after the surgery.Results The histological examination of the specimens showed bone formation was found underneath the space maintaining device but didn′t fill the space.The shape of new bone was in accord with the outline of the elevated membrane.The newly formed bone was immature woven bone and composed of trabecular bone structure.New bone area was (8.17±5.63) mm2 and (9.92±4.65) mm2 respectively in the condition of membrane intactness and perforation.The difference was not significant.Conclusions New bone formation can be found in nongrafted maxillary sinus bone augmentation using space maintaining device and the small perforation has no effect on it.The mechanism of new bone formation remains to be explored.

Key words: nongrafted , maxillary sinus bone augmentation, space maintaining , new bone formation , beagle dog