• The Journal of the Korean dental association
• /
• v.15 no.8
• /
• pp.623-626
• /
• 1977

The author made two implant blades of gold alloy metal, and applied CEKA attachment to one blade. These two blades were implanted at the sockets resulting from removal of both 3rd premolar of experimental dog. Simple crown and tooth supporting denture was constructed on the implanted blades the author observed above mentioned procedures for 8 weeks. The obtained results were as follows; 1) There is no remarkable necrosis of supporting alveolar bone on both sides So, metal reaction was favourable. 2) Masticatory force which is loaded on each tooth was not effective on the alveolar bone.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.2
• /
• pp.256-268
• /
• 1999

Submerged implants require secondary surgical uncovering of implants after healing period of 3-6 months. In surgical methods, there are surgical scalpel, tissue punch, electro-surgical, and laser-used uncovering, and so forth The objectives of this study are investigation and assessment of 1) thermal change in clinical application for uncovering of HA-coated implant and pure titanium implant irradiated by pulsed Nd-YAG, $CO_2$, and Er-YAG laser. 2) surface change of cover screws aaer irradiation using laser energy. The temperature of apex & side wall of implants were recorded at 10sec, 20sec, 30sec after 30sec irradiation to implant healing screw; 1) pulsed Nd-YAG laser; 2W, 20pps, contact mode 2) $CO_2$ laser; water-infused & non-water infused state, 2.5-3.5W, contibuous mode, noncontact mode 3) $CO_2$ laser ; non-water infused state, 3W, superpulse, noncontact. mode 4) Er-YAG laser; (1) non-water infused state, 10pps, 60mj, contact mode (2) water-infused state, 10pps, 60mj, 80mj, 101mj, contact mode. According to the results of this study, pulsed Nd-YAG laser is not indicated because of increased thermal change and pitting of metal surface of implant cover screw. By contrast, $CO_2$ laser & Er-YAG laser are presumed to indicate because of narrow range of thermal change & near abscence of thermal damage of metal surface. Dental laser is thought to be much helpful to surgical procedure when it is used as optimal power and time condition considering characteristics and indications of each laser. Further research is needed to verify that these techniques are safe and beneficial to implant success.

• The Journal of Korean Academy of Prosthodontics
• /
• v.62 no.3
• /
• pp.234-242
• /
• 2024

Immediate implant placement and restoration have the advantage of shortening the treatment period and maintaining aesthetics until final restoration. However, single implant restoration in the maxillary anterior region may be aesthetically difficult, and surgical trauma delivered to soft and hard tissues during implant placement may affect future aesthetic results. In order to obtain predictable results during anterior implant placement and restoration, surgery and restoration plans must consider the height of the interdental bone, characteristics of the gingiva, and morphological characteristics of the patient's teeth. In this case, we attempted to reproduce the emergence profile and stabilized soft tissue through gingiva modification and digital impression of a labially placed maxillary anterior implant in a patient who desired porcelain fused-metal (PFM) restoration due to economic issues.

• Imaging Science in Dentistry
• /
• v.37 no.3
• /
• pp.127-131
• /
• 2007

Purpose: To measure the differences of the splint pin angulation and the position of the planned implant site after conventional tomographic analysis. Materials and Methods: The angulation and the location of the metal splint pin retained in acrylic stent were compared with the corrected angulation and the location of the implant fixture on the 331 tomographic images. Results: The stent pins were located buccal in 40%, lingual in 10% to the corrected implant site after analysis of the conventional tomographic image. The angle and the location of the maxillary splint pin were mainly directed buccal on incisor and canine regions. The angle and the location of the splint pins in premolar and molar regions needed less corrections in both maxilla and mandible. Conclusions: This study demonstrated that the use of tomographs was essential for successful dental implant planning.

• Korean Journal of Computational Design and Engineering
• /
• v.13 no.3
• /
• pp.200-208
• /
• 2008

Total Hip Replacement(THR) is a surgical procedure that replaces a diseased hip joint with a prosthesis. A plastic or metal cup forms the socket, and the head of the femur is replaced by a metal ball on a stem placed inside the femur. Due to the various types and shapes of human hip joint of every individual, a selected commercial implant sometimes may not be the best-fit to a patient, or it cannot be applied because of its discrepancy. Hence extracting geometry parameters of hip joint is one of the most crucial processes in designing custom-made implants. This paper describes the framework of a methodology to extract the geometric parameters of the hip joint. The parameters include anatomical axis, femoral head, head offset length, femoral neck, neck shaft angle, anteversion, acetabulum, and canal flare index. The proposed system automatically recommends the size and shape of a custom-made hip implant with respect to the patient's individual anatomy from 3D models of hip structures. The proposed procedure creating these custom-made implants with some typical examples is precisely presented and discussed in this paper.

• Journal of information and communication convergence engineering
• /
• v.11 no.4
• /
• pp.288-292
• /
• 2013

In this paper, a carbon implant is investigated in detail from the perspectives of performance advantages and side effects for the thick n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET). Threshold voltage ($V_{th}$) adjustment using a carbon implant significantly improves the $V_{th}$ mismatch performance in a thick (3.3-V) n-MOS transistor. It has been reported that a bad mismatch occurs particularly in the case of 0.11-${\mu}m$ $V_{th}$ node technology. This paper investigates a carbon implant process as a promising candidate for the optimal $V_{th}$ roll-off curve. The carbon implant makes the $V_{th}$ roll-off curve perfectly flat, which is explained in detail. Further, the mechanism of hot carrier injection lifetime degradation by the carbon implant is investigated, and new process integration involving the addition of a nitrogen implant in the lightly doped drain process is offered as its solution. This paper presents the critical side effects, such as Isub increases and device performance shifts caused by the carbon implant and suggests an efficient method to avoid these issues.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.4
• /
• pp.402-411
• /
• 2000

The dental profession is currently experiencing a technology explosion. Processes are being replaced by modern, inexpensive, and precise techniques that can be used to solve complex restorative problems. Electrical discharge machining(EDM, known as spark erosion in Europe) is a nonconventional, industrial technique that has application in dentistry. EDM may be defined as a metal removal process using a series of sparks to erode material from a workpiece in a liquid medium under carefully controlled conditions. EDM is recently adopted in the dental laboratory to fabricate precision attachments, hybrid tele-scope crowns, Ti-ceramic crowns. EDM has also been used to achieve a passive precision metal-to-metal fit between the substructure bar and the removable superstructure and to correct the fit of implant retained restorations. In this article, a brief history and explanation of EDM is discussed and a description of the use of this process for fabricating attachments and crowns or for correcting the fit of cast restorations is presented.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.25 no.4
• /
• pp.403-415
• /
• 2009

The purpose of the study is to establish the effect of different abutment shapes and types of cements on the retention of the full veneer casted gold crowns. Metal dies that has the similar shape with the implant abutment were manufactured using a short(5mm) and long(10mm) dies with different convergence angles. Metal dies and gold crowns, which were made from the metal dies, were cemented with Temp-bond, Temp-bond mixed with petroleum jelly, ZPC and Premier implant cement. After that, these were tested for tensile force at the point of separation. The effect of convergence angle changes of different cement types on the retention was studied as well as the effects of the cement type changes with different convergence angles on the retention. In addition, study about the marginal gap of Premier implant cement used for this experiment was conducted. The results are as followed under the in-vitro experimental limits; 1. The retention of the Temp-bond mixed with petroleum jelly decreased as the convergence angle increased, and the retention was weakest among the cements. 2. The retention of ZPC decreased as convergence angle increased. When convergence angle was 5 degrees, ZPC showed stronger retention than Premier implant cement. 3. Premier implant cement had the weakest retention when the convergence angle was 5 degrees but when the convergence angle was 10 degrees, it had the strongest retention. As the angle increased more than 10 degrees, the retention decreased. 4. Premier implant cement showed bigger marginal gap when the convergence angle was 5 degrees than 10 degrees under the experimental condition.

• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.2
• /
• pp.164-173
• /
• 2009

Purpose: The purpose of this study was to evaluate the effect of abutment material on screw-loosening before and after cyclic loading. Among the different materials of abutments, zirconia and metal abutment were used. Material and methods: Two types of implant systems: external butt joint(US II, Osstem Implant, Korea) and internal conical joint(GS II, Osstem Implant, Korea) were used. In each type, specimens were divided into two different kinds of abutments: zirconia and metal(n=5). The implant was rigidly held in a special holding to device ensure fixation. Abutment was connected to 30 Ncm with digital torque gauge, and was retightened in 30 Ncm after 10 minutes. The initial removal torque values were measured. The same specimens were tightened in 30 Ncm again and held in the cycling loading simulator(Instron, USA) according to ISO/FPIS 1480. Cycling loading tests were performed at loads 10 to 250 N, for 1 million cycles, at 14 Hz,(by subjecting sinusoidal wave from 10 to 250 N at a frequency of 14 Hz for 1 million cycles,) and then postload removal torque values were evaluated. Results: 1. In all samples, the removal values of abutment screw were lower than tightening torque values(30 Ncm), but the phenomenon of the screw loosening was not observed. 2. In both of the implant systems, initial and postload removal torque of zirconia abutment were significantly higher than those of metal abutment(P<.05). 3. In both of the implant systems, the difference in removal torque ratio between zirconia abutment and metal abutment was not significant(P>.05). 4. In metal abutments, the removal torque ratio of GS II system(internal conical joint system) was lower than that of US II system(external butt joint system)(P<.05). 5. In zirconia abutments, the difference in removal torque ratio between the two implant systems was not significant(P>.05). Conclusion: Zirconia abutment had a good screw joint stability in the condition of one million cycling loading.

• Imaging Science in Dentistry
• /
• v.50 no.1
• /
• pp.23-30
• /
• 2020

Purpose: This study was conducted to assess the effectiveness of a metal artifact reduction (MAR) algorithm activated at different times during cone-beam computed tomography (CBCT) acquisition on the magnitude of artifacts generated by a zirconium implant. Materials and Methods: Volumes were obtained with and without a zirconium implant in a human mandible, using the OP300 Maxio unit. Three modes were tested: without MAR, with MAR activated after acquisition, and with MAR activated before acquisition. Artifacts were assessed in terms of the standard deviation (SD) of gray values and the contrast-to-noise ratio (CNR) in 6 regions of interest with different distances (10 to 35 mm, from the nearest to the farthest) and angulations(70° to 135°) from the implant region. Results: In the acquisitions without MAR, the regions closer to the implant(10 and 15mm) had a higher SD and lower CNR than the farther regions. When MAR was activated (before or after), SD values did not differ among the regions (P>0.05). The region closest to the implant presented a significantly lower CNR in the acquisitions without MAR than when MAR was activated after the acquisition; however, activating MAR before the acquisition did not yield significant differences from either of the other conditions. Conclusion: Both modes of MAR activation were effective in decreasing the magnitude of CBCT artifacts, especially when the effects of the artifacts were more noticeable.