Objectives:In this research, the morphological changes of gingival microvasculature after ultrasonic tooth preparation were observed three-dimensionally by the microvascular resin cast method.

Methods:Premolars and molars with healthy periodontal tissues of four beagle dogs were used. First, preparation was carried out with a rough diamond bar by a dental turbine in general form along the height of the gingival margin, after which a newly developed diamond tip with ultrasonic wave (32khz) instruments was used to create the deep chamfer preparation. As a control, the same size and structure of a conventional diamond bar was used with the dental turbine. The micro vascular resin cast model was made, synthetic resin was injected from the alveolar arteries and peripheral tissues were dissolved with a 10% Hcl and 15% KOH solution. These specimens were examined under a scanning electron microscope (SEM).

Results:In the observation of the micro vascular cast, a healthy gingival vasculature beneath the sulcular epithelium was arranged in dense vascular loops. The vascular network beneath the attached epithelium was made up of a squamous mesh. In the ultrasonic preparation group, the vasculature closely resembles healthy gingiva and in the dental turbine group, the vascular network of the sulcular epithelium changed into a dilated renal glomerulus-like form. The injected vascular resin leaked out from the blood vessels beneath the epithelium.

Conclusions:The leakage of the resin from the blood vessels was observed in the dental turbine group, which means not only the destruction of blood vessels but also that the endothelial cell gap opens by hyper permeability in the attached epithelium area. In the ultrasonic preparation, the blood vessels did not changed and the vasculature showed a form equal to the healthy gingiva. These results suggest that preparation by ultrasonic instruments minimizes damage to the gingival tissue.

Back to the Prosthodontics Research Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

Top Level Search