• 대한치과보철학회지
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• 제35권1호
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• pp.43-66
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• 1997

Dental implant may be immediately placed in postextraction socket which has alveolar bone defect. The purpose of this study was to compare the bone regeneration and bone quality around defects adjacent to implants that were placed into extraction sockets according to EFEB, GTAM barrier and GTAM barrier with DFDB. Mandibular P2, P3 and P4 were extracted bilaterally in dogs, and buccal defects were created about 4mm in depth and 3.3mm in width. Screwed pure titanium implants, 3.8mm in diameter and 10mm in length, were placed into the extraction sockets. The experimental groups were divided into four groups : the G group was covered with a GTAM barrier on the defective area, the D+G group was filled with DFEB and covered with a GTAM barrier, the D group was filled with DFDB only and the control group was sutured without any special treatment on the defective area. The experimental animals were killed after 12 weeks and specimens were prepared for light microscopic evaluation and fluorescent dyes were administered daily for 2 weeks after implantation, and injected on the 4th and 11th week for fluorescent microscopic examination to observe new bone formation and bone remodeling. The new Bone height of the buccal defect was measured and compared with the another for bone gain and the removal torque for the implant was measured for the comparison of bone density and bone-implant osseointegration. Results obtained were as follows : 1. Experimental groups showed bone regeneration in oder from D+G, G, D group and control. D+G and G group was significantly from D group and control(P<0.01). 2. In the defective area of control the regenerated alveolar bone showed poorly developed lamellated structure and fibrous tissue intervention into the bone-implant interface but the others showed well developed lamellated structure and osseointegration. 3. All implant groups showed no significaant difference in the removal torque for implant(P>0.05) These results suggest that immediate implants placed in defective sockets were successfully osseointegrated and utilizing placed in defective sockets were successfully osseointegrated and utilizing not only the combination of GTAM and DFDB but also only the GTAM was favorable for the predictable regeneration of the defective area.

• 한국언어정보학회지:언어와정보
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• 제13권1호
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• pp.127-143
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• 2009

Tough-construction is, undoubtedly, one of the most puzzling syntactic problems in the history of transformational grammar. Various approaches have been proposed including Deletion approaches (Akmajian, 1972; Lasnik and Fiengo, 1974) and movement approaches. Among the movement approaches, Chomsky (1977; 1981) argues for movement of null Operator, and Hornstein (2001) argues for a two-step movement equipped with Sideward movement. Most recently, Schueler (2004) and Hartman (2009) each have also argued for a kind of movement approach. With the development of the Minimalist syntax (Chomsky, 1995; Chomsky, 2000; Chomsky, 2001), tough-construction, an age old problem in the description of grammar, turns into another round toward to a more satisfactory answer. By examining the most recent competing analyses of tough-constructions, this paper defends and extends Schueler's (2004) analysis, rather than Hartman's (2009) two step movement approach. Furthermore, this paper proposes that tough-subject originates from the intermediate CP internal Spec-TopicP position rather than from the iterated CP layer (Authier, 1992). This approach has more descriptive power than it was originally argued for in Schueler (2004) and is a step closer toward Minimalism insofar as the conception of government is no longer utilized.