Development of Translucent Three-dimensional Vital Microscopy in Dental Research

Objectives: Our team examines the vasoactive materials related reactions of gingival superficial venules with vital microscopy. The lack of tissue transparency and the missing of one dimension (depth) constrained our work so far. In order to access the deeper vascular network, it became necessary to develop a biocompatible substance that helps to increase the gingival translucency so as to have visual access to the profound layers. Development and determination of in vivo feasibility of this supporting solution and a unique 3D vital microscopy system have become the main goal of our research group. Methods: The tissue clearing test solutions were adjusted similar to the extracellular fluid, and the absorbance change induced was measured in vitro using different tissue samples (skeletal muscle, submandibular gland, intestine, liver, kidney). Moreover, our staff developed a 3D imaging system, which consists of a stereo microscope, 2 stereo converters, 2 high-resolution cameras connected to the ocular of the stereo microscope, 2 monitors with a special glass plate used for imaging, and a computer software with 3D measuring capability. We tested the system in vivo on rat microcirculation and secretion (gingiva, submandibular gland). Repeated Measures ANOVA was applied for statistical analysis. Results: We demonstrated that the developed solutions significantly increased the transparencies of the treated tissues. The absorbance values of the samples were reduced by nearly 50-60 % after 60 minutes, when they reached a plato phase and remained stable in the following 60 minutes. In vivo preliminary experiments confirm this fact. Conclusions: The solution, the protocol and the set up which have been developed, technically allow the implementation of translucent 3D vital microscopy, a cutting edge, incomparable investigation method that allows to make high fidelity 3D observations in vivo in different organs in a so far unavailable manner. Supports: Hungarian OTKA T049708, Faculty Research Application FOK/DH/3-5/2011.