• Journal of Periodontal and Implant Science
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• 제52권4호
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• pp.338-350
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• 2022

Purpose: Various studies have investigated 3-dimensional (3D)-printed implants using Ti6Al-4V powder; however, multi-root 3D-printed implants have not been fully investigated. The purpose of this study was to explore the stability of multirooted 3D-printed implants with lattice and solid structures. The secondary outcomes were comparisons between the 2 types of 3D-printed implants in micro-computed tomographic and histological analyses. Methods: Lattice- and solid-type 3D-printed implants for the left and right mandibular third premolars in beagle dogs were fabricated. Four implants in each group were placed immediately following tooth extraction. Implant stability measurement and periapical X-rays were performed every 2 weeks for 12 weeks. Peri-implant bone volume/tissue volume (BV/TV) and bone mineral density (BMD) were measured by micro-computed tomography. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were measured in histomorphometric analyses. Results: All 4 lattice-type 3D-printed implants survived. Three solid-type 3D-printed implants were removed before the planned sacrifice date due to implant mobility. A slight, gradual increase in implant stability values from implant surgery to 4 weeks after surgery was observed in the lattice-type 3D-printed implants. The marginal bone change of the surviving solid-type 3D-printed implant was approximately 5 mm, whereas the value was approximately 2 mm in the lattice-type 3D-printed implants. BV/TV and BMD in the lattice type 3D-printed implants were similar to those in the surviving solid-type implant. However, BIC and BAFO were lower in the surviving solid-type 3D-printed implant than in the lattice-type 3D-printed implants. Conclusions: Within the limits of this preclinical study, 3D-printed implants of double-rooted teeth showed high primary stability. However, 3D-printed implants with interlocking structures such as lattices might provide high secondary stability and successful osseointegration.

• 한국토양비료학회지
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• 제6권3호
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• pp.141-152
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• 1973

화강암(花崗岩), 화강섬록암(花崗閃綠岩), 섬록암(閃綠岩), Arkose 질사암(質砂岩), 및 Tertiary 혈암(頁岩)등에 유래(由來)된 사과과수원(果樹園) 11개처(個處)의 하층토(下層土)에 대(對)해서 광물(鑛物)의 풍화과정(風化過程)과 토양생성작용(土壤生成作用) 및 광물조성(鑛物組成)과의 관계(關係)를 밝히기 위(爲)하여 일(一), 이차광물(二次鑛物)에 대(對)한 광물학적(鑛物學的) 연구(硏究)를 시도(試圖)한 결과(結果)는 다음과 같다. 1. 일차광물(一次鑛物)로서 Quartz, Changed-feldspar, Plagioclase, Alkali-feldspar 등은 거의 모든 시료(試料)에 존재(存在)하였고, 또 시료(試料)에 따라 Hornblende, Biotite, Muscovite 및 Plant opal를 가진 것도 있었으며, 그 밖에 양(量)은 적으나마 Pyroxene group, Tourmaline, Epidote, Cyanite, Magnetite, Volcanic glass 및 Zircon 등도 찾아 볼 수 있었다. 토양(土壤)의 광물학적조성(鑛物學的組成)은 모재(母材)의 특성(特性)을 어느정도(程度) 반영(反映)하고 있어서, 주(主)로 Granite, Granodiorite, Diorite, Arkose 또는 그들의 풍화생성물(風化生成物)이 서로 혼입(混入)된 것에 유래(由來)된 것으로 추정(推定)할 수 있었다. 2. 점토광물조성(粘土鑛物組成)은 팽창형(膨脹型) 또는 비팽창형(非膨脹型) ${\AA}14$광물(鑛物), Illite 및 Kaolin 광물(鑛物)이 주성분(主成分)으로 되고, 시료(試料)에 따라서는 Chlorite, Christobalite, Gibbsite와 일차광물(一次鑛物)인 Quartz 및 Feldspar를 가지고 있었으나 양적(量的)으로는 모재(母材)에 따라 차(差)가 있었다. 3. 비팽창형(非膨脹型) $14{\AA}$광물(鑛物)로는 2, 8면체(面體) Vermiculite가 주(主)이고, 그 층격자간(層格子間)에 Gibbsite 모양의 수산화(水酸化) Aluminium 층(層)을 끼워 있는 것으로 추정(推定)된다. 4. Arkose 또는 Tertiary 혈암계암석(頁岩系岩石) 풍화생성물(風化生成物)에 유래(由來)된 것은 Montmorillonite가 주성분(主成分)이 였다. 그러나 Arkose만으로 된 것은 Kaolin 광물(鑛物)과 Vermiculite가 주(主)이고, 또 산성암풍화생성물(酸性岩風化生成物)이 주(主)로 된 곳은 Kaolin 광물(鑛物)을 주성분(主成分)으로 하는 것과, Kaolin 광물(鑛物) 및 Vermiculite를 주성분(主成分)으로 하는 두 Group로 크게 나눌 수 있었다.