• Journal of Periodontal and Implant Science
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• v.53 no.4
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• pp.295-305
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• 2023

Purpose: Various methods have been proposed to achieve the nearly complete decontamination of the surface of implants affected by peri-implantitis. We investigated the in vitro debridement efficiency of multiple decontamination methods (Gracey curettes [GC], glycine air-polishing [G-Air], erythritol air-polishing [E-Air] and titanium brushes [TiB]) using a novel spectrophotometric ink-model in 3 different bone defect settings (30°, 60°, and 90°). Methods: Forty-five dental implants were stained with indelible ink and mounted in resin models, which simulated standardised peri-implantitis defects with different bone defect angulations (30°, 60°, and 90°). After each run of instrumentation, the implants were removed from the resin model, and the ink was dissolved in ethanol (97%). A spectrophotometric analysis was performed to detect colour remnants in order to measure the cumulative uncleaned surface area of the implants. Scanning electron microscopy images were taken to assess micromorphological surface changes. Results: Generally, the 60° bone defects were the easiest to debride, and the 30° defects were the most difficult (ink absorption peak: 0.26±0.04 for 60° defects; 0.32±0.06 for 30° defects; 0.27±0.04 for 90° defects). The most effective debridement method was TiB, independently of the bone defect type (TiB vs. GC: P<0.0001; TiB vs. G-Air: P=0.0017; TiB vs. GE-Air: P=0.0007). GE-Air appeared to be the least efficient method for biofilm debridement. Conclusions: T-brushes seem to be a promising decontamination method compared to the other techniques, whereas G-Air was less aggressive on the implant surface. The use of a spectrophotometric model was shown to be a novel but promising assessment method for in vitro ink studies.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.705-715
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• 2003

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically compomer and Ketac Silver as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiostcal flap was elevated. Following decortication with 1/2 high speed round bur, furcation defect was made on maxillary premolar. 2 month later one premolar was filled with compomer and the other premolar was filled with Ketac Silver. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with H-E staining. Results were as follows. 1. Compomer & Ketac Silver restoration were encapsulated fine connective tissue. 2. In 4 weeks, compomer & Ketac Silver restoration slightly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, compomer & Ketac Silver restoration were less infiltrated iflammatory cell and encapsulated fine connective tissue. 4. Therefore, compomer & Ketac Silver filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances is possible clinical method and this technique is useful method for maxillary furcation involvement but it is thought that periodic maintenance should be needed

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.793-803
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• 2000

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically self-curing glass-ionomer cement and light-curing glass-ionomer cement as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on maxillary third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were self-curing glassionomer cement and light-curing glassionomer cement. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. Results were as follows. 1. In all experiment group, there were not epithelial down growth and glass ionomer cement were encapsulated connective tissue. 2. In 4 weeks experiment I group slighly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, experiment groups I, II were encapsulated fine connective tissue. 4. Therefore glass-ionomer cement filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances were possible clinical methods and this technique is useful method for Maxillary furcation involvement.

• Journal of the Korean Magnetics Society
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• v.26 no.1
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• pp.24-30
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• 2016

MFL (Magnetic flux leakage) type nondestructive testing has been used for inspection of underground gas pipelines to find metal defects by detecting magnetic leakage signal. Because the underground gas pipeline is exposed by environment such as high pressure with great humidity, external defects are easily formed on the surface of pipelines and they are being grouped respectively. These adjacent defects cause the signal distortion of leakage flux so that it is hard to estimate the shape information of defects. In this paper, we performed to study of the signal distortion and compensating method for multiple defects in MFL type nondestructive testing system by using 3D FEM simulation. This paper proposes the basic algorithm of defect signal analysis on multiple defects on the surface of 30 inch diameter pipeline.

• Journal of the Korean Vacuum Society
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• v.16 no.1
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• pp.27-32
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• 2007

We have investigated photoluminescence(PL) spectra of four $In_xGa_{1-x}N(x=0.15)/GaN$ multiple quantum well(MQW) structures with different well widths in order to study a phenomenon on crystal phase separation. The asymmetic behavior of PL spectra becomes stronger with increase of the well width from 1.5 nm to 6.0 nm, which indicates dual-peak nature. Analyzing the dual-peak fit PL spectra, we have observed that the intensity of low-energy shoulder peak rapidly becomes stronger, compared to that of high-energy peak corresponding to a transition in InGaN QW. It suggests that InGaN QW has two phases with tiny different In compositions, and that In-rich(InN-like) phase forms more and more relatively than stoichiometric InGaN(x=0.15) phase by the InN phase separation mechanism as the QW width increases. PL spectrum of 6.0-nm sample shows an additional peak at low-energy lesion(${\sim}2.0\;eV$) whose energy position is almost the same as a defect band of yellow luminescence frequently observed in GaN epilayers. It may be due to a defect resulted from In deficiency formed with development of the phase separation.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.391-398
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• 2011

The infraocclusion usually occurs in the mixed-dentition stage, and it is commonly accepted that the cause of the infraocclusion is ankylosis. The treatment options for patient with infraocclusion of primary molars are observation, restoration or surgical removal of the affected teeth. If the successors are present, most of the infraoccluded and ankylosed primary molars may occur normally. However, when the permanent successors are absent and the progression of infraocclusion is found, affected teeth may need to be extracted. In the case of infraocclusion which can cause vertical alveolar defect due to ankylosis, extraction before growth spurt should be performed for the future prosthetic treatment. A six-year-old female had the ankylosis and infraocclusion of multiple primary molars and congenital missing of premolars. The affected primary molars were extracted before growth spurt to avoid a significant vertical ridge defect and to promote the vertical development of alveolar bone, and the result was observed for many years. The purpose of this report is to report the management of multiple infraoccluded primary molars without permanent successors in a young patient.

• Archives of Reconstructive Microsurgery
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• v.10 no.2
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• pp.81-85
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• 2001

In the treatment of urethral stricture, many problems still remain with the current methods making it a field of further exploration for reconstructive surgeon. Furthermore, when total or multiple strictures of the penile urethra exist, the methods of surgery become difficult due to a necessity for a long neourethra. Introduction of vascularized free flap has broadened the choice and improved the results of reconstruction for the urethra. The authors used a sensate ulnar forearm free flap in a patient with multiple penile urethral strictures for reconstruction. Uroflowmetry, 30 months after surgery, revealed that maximal flow rate was 15.5 ml/sec, average flow rate was 9.5 ml/sec, and voided volume was 157 ml. A urethrogram was performed 30 months postoperatively and a good result was achieved. The ulnar forearm free flap used by the authors are thin and pliable and is good for providing sufficient length to reconstruct the neourethra for a long urethral defect.

• Archives of Craniofacial Surgery
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• v.10 no.1
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• pp.40-43
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• 2009

Purpose: Extensive midface defect following total maxillectomy with orbital exenteration and cheek skin resection should be three dimensionally reconstructed with a large flap that have a sufficient volume of tissue and multiple skin islands. We describe our transverse rectus abdominis myocutaneous(TRAM) free flap with three skin islands which was successfully used in this situation. Methods: A 58-year-old man was performed enbloc total maxillectomy including orbital contents and wide cheek skin because of invasive maxillary squamous cell carcinoma. He was immediately reconstructed with TRAM flap that was designed not vertical but transverse fashion for providing sufficient skin area. Also, deepithelialization procedure making for multiple skin islands was done in flap insetting period when appropriate modification according to the intraoperative situation was possible. Dead space was completely obliterated by bulky muscular tissue, and three skin islands were used for lining of lateral nasal wall, palatal surface, and cheek skin restoration. Results: Postoperative course was satisfying. Maintaining of proper ipsilateral nasal airway, loss of rhinolalia and oronasal regurgitation of food particles, and restoration of cheek contour were successfully obtained. Conclusion: We report clinical experience of threedimensional reconstruction using free TRAM flap after total maxillectomy with orbital exenteration.

• Journal of The Korean Dental Society of Anesthesiology
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• v.11 no.2
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• pp.177-182
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• 2011

There are five principal causes for excessive bleeding in the immediate postextraction phase ; (1) Vascular wall alteration (wound infection, scurvy, chemicals, allergy) (2) Disorders of platelet function (genetic defect, drug-aspirin, autoimmune disease) (3) Thrombocytopenic purpuras (radiation, leukemia), (4) Inherited disorders of coagulation (hemophilia, Christmas disease, vitamin deficiency, anticoagulation drug-heparin, coumarin, aspirin, plavix). If the hemorrhage from postextraction wound is unusually aggressive, and then dehydration and airway problem are occurred, the socket must be packed with gelatine sponge(Gelfoam) that was moistened with thrombin and wound closure & pressure dressing are applied. The thrombin clots fibrinogen to produce rapid hemostasis. Gelatine sponges moistened with thrombin provide effective coagulation of hemorrhage from small veins and capillaries. But, in dental alveoli, gelatine sponges may absorb oral microorganisms and cause alveolar osteitis (infection). This is a case report of bleeding and infection control by the circumferential suture and iodoform gauze drainage on infected active bleeding extraction socket under sedation and local anesthesia in a 71-years-old male patient with anticoagulation drug.

• Archives of Craniofacial Surgery
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• v.20 no.3
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• pp.203-206
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• 2019

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroectodermal carcinoma arising from mechanoreceptor Merkel cells. Multiple MCCs are even rarer. We report a case of two independent MCCs simultaneously present in the cheek of a patient, which were effectively and esthetically treated using a cheek flap. Punch biopsy performed in a 60-year-old woman admitted with a chief complaint of two skin-colored hard nodules in her left cheek, accompanied by an itching sensation, was suggestive of MCC. Accordingly, we performed sentinel lymph node biopsy through the modified Blair incision under general anesthesia, in cooperation with the head and neck surgery department. The defect was covered with a cheek flap by slightly extending the existing incision following wide excision with a safety margin of 1 cm. This paper is significant in that it introduces an effective reconstruction technique that maintains function using a cheek flap for the management of this rare case. In addition, this paper is the first to classify multiple MCCs according to the time of onset. We believe that this paper presents an effective alternative reconstruction technique with sentinel node biopsy through the modified Blair incision.