Comparison of Macro-and Micro-porosity of a Titanium Mesh for Guided Bone Regeneration: An In Vivo Experimental Study

Guided bone regeneration (GBR) is one of the surgical methods used for vertical ridge augmentation prior to dental implant placements. Titanium meshes have been used for osteogenic space maintenance in GBR sites by clinicians. We aimed to compare the influence of micropores and macropores in a titanium mesh on bone regeneration in a rat calvarial vertical GBR model.

The calvaria of nine rats were exposed, and plastic cylinders were set bilaterally. Eighteen surgical sites were randomly allocated into three groups according to the materials of titanium lid and bone substitutes: microporous titanium lid+deproteinized bovine bone mineral (DBBM), macroporous titanium lid +DBBM, microporous titanium lid+carbonate apatite. Newly generated bone inside the cylinders was evaluated using micro-computed tomography (micro-CT). Furthermore, bone regeneration and angiogenesis were evaluated histologically at 12 weeks.

Quantitative volumetric analyses using micro-CT showed a gradual increase in bone volume inside the cylinders in all three groups. Histological observation confirmed vigorous bone regeneration in the microporous groups compared to that in the macroporous group. In the upper part of the cylinders, soft tissue invaded the GBR site by passing through the pores of the macroporous mesh. The blood vessels in the upper part of the cylinders were smaller in the microporous groups than in the macroporous group. There was no difference in bone formation between cylinders filled with DBBM or carbonate apatite.

Microvasculature penetrates 50-μm diameter micropores and accelerates bone formation inside the cylinder, which was set on rat calvaria. The microporous titanium mesh can facilitate angiogenesis from both the dura mater and periosteal in vertical ridge augmentation. Our data showed superiority of microporous titanium vascular permeability and osteoconductivity, supporting bone growth.