• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.330-337
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• 2016

Gingival recession could occur after orthodontic or endodontic treatment. This could influence not only functional and aesthetic problem, but also patient's treatment satisfaction. There are a lot of techniques for preventing gingival recession, but laterally positioned flap with subepithelial connective tissue graft could get definite advantages such as increase of keratinized gingival width and harmonious color match between graft tissue and surrounding tissue. Clinician should select a right patient case and diagnosis with clinical and radiography exam. In a surgical procedure, getting enough amounts of subepithelial connective tissue and flap coverage should be taken into consideration. The clinical outcomes in this case report shows laterally positioned flap with subepithelial connective tissue graft could be a treatment with predictive outcome.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.437-449
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• 2001

The socket preservation procedure was a simple and effective technique, and has better prognosis for implantation. The socket preservation usually used barrier membrane in combination with/without alloplastic bone materials. A recently study had shown that a regenerative therapy to tooth extraction utilizing growth factors made better results. Platelet-rich plasma was clinically easy method that acquired the growth factors, and is known that accelerated new bone formation and mineralization of bone graft materials. The purpose of this study was to evaluate clinical and histopathologic results which occur following socket preservations using platelet-rich plasma and bovine bone powder. Twelve patients who required extraction of one or more teeth for implantation at the department of periodontics in Dankook University Dental Hospital were selected. Extraction sockets were treated by using platelet-rich plasma and bovine bone powder. 3 months later, we observed clinical and histopathological results as follows: 1. Internal vertical measurement was an average of 7.33mm preoperatively and statistically significantly decreased to an average of 1.42mm postoperatively(p<0.05). 2. External vertical measurement was an average of 3.33mm preoperatively and decreased to an average of 2.75mm postoperatively; therefore there was no significant difference. 3. Horizontal measurement was an average of 7.75mm preoperatively and statistically decreased to an average of 6.08mm postoperatively(p<0.05). 4. Osteocyte-like cells and new bone formation connected with bovine bone grafts were observed in histopathologic examination. This study implied that platelet-rich plasma and bovine bone powder grafts were effective treatment for socket preservation and regeneration of severe bony defect made by implantation failure.

• Restorative Dentistry and Endodontics
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• v.42 no.2
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• pp.105-110
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• 2017

Objectives: This study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos $Odontol\acute{o}gicos$) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated. Materials and Methods: Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). Results: There were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05). Conclusions: QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.350-357
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• 2007

Bone graft had been widely investigated for reconstruction of bone defects or acceleration of bone healing in orthopedics, neurosurgery and dental surgery. Autograft is the golden standard of bone graft but it is associated with donor site morbidity and is restricted in quantity. Xenograft has been researched an alternative method for autograft. The purpose of this study was to investigate the efficacy of new bone formation according to three different preparations of implants on rabbit xenograft. Cortical bone xenografts which made from bovine femoral cortical bone were treated by freezing, freeze-drying or defat-freezing implant preparations. They were transplanted into proximal diaphyseal shaft of bifibulae of 15 rabbits which were divided into three groups according to their implant preparation method. The fibulae transplantations were evaluated radiographically and examined osteoblast activity by bone alkaline phosphatase (BALP) biweekly for 16 weeks to observe new bone formation and union of the experimental defected region. New bone formation was observed in 7 cases in freeze-drying and defat-freezing group, respectively. Union of proximal and distal end of defected region, which was considered as success of bone graft, was observed in 4 cases (40%; 4 of 10 cases), respectively. In freezing group, new bone formation was observed in 6 cases but, there is no union observed. BALP value was increased over twice after two weeks of graft procedure in all union cases of freeze-drying and defat-freezing group (two of five animals, respectively) then gradually decreased to 16th week. In non-union cases, there is no significant variation in BALP value. Defat-freezing or freeze-drying preparations of implants are more efficacious in new bone formation than freezing method on rabbit xenograft. While it is difficult to propose which is superior between defat-freezing and freeze-drying, defatting of implants may enhance new bone formation in xenograft.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.468-476
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• 1998

The purpose of this study was to observe the morphologic change of dentinal surface, adhesion in interface between dentin and bonding agents, and penetration pattern of resin tags into dentinal tubles according to bonding procedure of ONE-STEP universal adhesive system. Ten extracted human molars were mounted in dental stone and sectioned to expose mid-coronal occlusal dentin and again sectioned tooth crown apically. Specimens were randomly assigned to three groups for dentin conditioning with 32% phoshoric acid, two coats of bonding agents after dentin conditioning, and bond of composite resin. The surfaces of dentin were treated with etch ant and applied bonding agent, and bonded composite resin according to the directions of manufacturer. Specimens which were boned composite were sectioned longitudinally for observing interfaces between resin and dentin. Two of specimens which were sectioned longitudinally were immersed in 6 N HCL for 30 seconds and 1% NaOCL for 12 hours to partially demineralize and deproteinize the dentin substrate. Each specimen was mounted on a brass stub, sputter-coated with gold and observed under SEM. The result were as follows : 1. On the dentinal surface which was conditioned with 32% phosphoric acid. the smear layer was completely removed. orifices of dentinal tubules were opened 3-$5{\mu}m$ wide. and dentinal surface was irregular. 2. On the dentinal surface which was applied ONE-STEP. bonding agent. resin particles were observed on the orifices of dentinal tubules and intertubular dentin. 3. There were close adaptation between dentin and resin and were the pattern which composite invaded into dentin. 4. 1-$3{\mu}m$-wide hybrid layer was visible in the interface between dentin and resin. 5. Long and funnel shaped resin tags were observed in demineralized specimens. and the surfaces of tags were rough.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.490-494
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• 2019

Abutment teeth supporting removable partial denture could be faced a number of problems including development of dental caries. If the existing removable partial denture is in clinically acceptable state and the patient does not want to replace the existing removable partial denture, then a new prosthesis for abutment teeth need to be made. The procedure of fabricating a new prosthesis of abutment teeth for existing removable partial denture is complicate and technically challenging. To fabricate the abutment crown, the original cast of patient obtained before any complication to the abutment teeth is required. The original cast should also contain teeth other than the abutment teeth as a reference point. Once the cast is prepared, CAD/CAM could be used to produce retrofitting prosthesis effortlessly and efficiently. This clinical report presents fabricating a crown to fit existing removable partial denture using CAD/CAM for a patient with post and core failure and dislodged prosthesis. The prosthesis had high stability with minimum adjustment yielding satisfying result.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.379-391
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• 2020

Purpose: The aims of this study were to evaluate the 5-year cumulative survival rate (CSR) of implants placed with guided bone regeneration (GBR) compared to implants placed in native bone, and to identify factors contributing to implant failure in regenerated bone. Methods: This retrospective cohort study included 240 patients who had implant placement either with a GBR procedure (regenerated bone group) or with pristine bone (native bone group). Data on demographic features (age, sex, smoking, and medical history), location of the implant, implant-specific features, and grafting procedures and materials were collected. The 5-year CSRs in both groups were estimated using Kaplan-Meier analysis. Risk factors for implant failure were analyzed with a Cox proportional hazards model. Results: In total, 264 implants in the native bone group and 133 implants in the regenerated bone group were analyzed. The 5-year CSRs were 96.4% in the regenerated bone group and 97.5% in the native bone group, which was not a significant difference. The multivariable analysis confirmed that bone status was not an independent risk factor for implant failure. However, smoking significantly increased the failure rate (hazard ratio, 10.7; P=0.002). Conclusions: The 5-year CSR of implants placed in regenerated bone using GBR was comparable to that of implants placed in native bone. Smoking significantly increased the risk of implant failure in both groups.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.223-228
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• 2018

Background and Objectives : Necortizing fasciitis in the cervical region is a very rare disease with high mortality and morbidity rates. The purpose of this study was to analyze the clinical characteristics, treatment results, complication and prognosis of necrotizing fasciitis patients. Materials and Methods : We retrospectively reviewed the inpatient charts treated for cervical necrotizing fasciitis at our Otorhinolaryngology clinic. We diagnosed necrotizing fasciitis by the clinical findings such as swelling, redness and pain of infected area and necrosis of subcutaneous fat layer and fascia observed during surgery. Twenty such patients were identified and treated from January 2011 to December 2016. Results : 20 adults consisting of 14 male and 6 females with cervical necrotizing fasciitis were diagnosed and treated. The most commonly known associated preceding illness were dental abscess and tonsillitis. The most pathogen was Streptococcus species (12/20), followed by Klebsiella pneumonia (6/20), Staphylococcus species (2/20). The mean duration of hospitalization was 32.2 days (range,14-86). The mean Modified Laboroatory Risk Indicator for Necrotizing Fasciitis (M-LRINEC) score is 7.4 and more than 4 points was eighteen. All patients received parenteral antibiotics and surgical drainage after admission. Conclusions : The reason for the high survival rate in the study was the early diagnosis, as well as the early surgical procedure and antibiotics. After the operation, frequent betadine irrigation could improve the patient's condition and recover without severe complication.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.195-201
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• 2022

Hemimandibulectomy and free fibular flap (FFF) in patients with squamous cell carcinoma could disturb the functional movement of the mandible. The muscular function in the sectioned side was compromised because of the incompetency of the muscle attachment to the mandible, leading to the unstable occlusal contact in the centric and eccentric occlusion. In this report, we present a case of a 63-year-old male who underwent cancer surgery and reconstruction with fibular graft, and he needed a fixed dental prosthesis to restore tooth loss in the anterior region. Occlusal contact change and instability were found according to the bite force in the centric relation and eccentric movement. This case report aimed to present the prosthetic procedure for fabricating the functionally optimized fixed prosthesis wherein the functionally generated path (FGP) technique and digital imaging method were applied to replicate mandibular movement and vertical dimension of the patient.

• Journal of Periodontal and Implant Science
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• v.52 no.5
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• pp.411-421
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• 2022

Purpose: In this study, we aimed to evaluate the degree of heat generation when a novel drill design with an irrigation slot was used with metal sleeve-free (MF) and metal sleeve-incorporated (MI) surgical guides in an environment similar to that of the actual oral cavity. Methods: A typodont with a missing mandibular right first molar and 21 bovine rib blocks were used. Three-dimensional-printed MF and MI surgical guides, designed for the placement of internal tapered implant fixtures, were used with slot and non-slot drills. The following groups were compared: group 1, MI surgical guide with slot drill; group 2, MI surgical guide with a non-slot drill; and group 3, MF surgical guide with a slot drill. A constant-temperature water bath at 36℃ was used. The drilling was performed in 6 stages, and the initial, highest, and lowest temperatures of the cortical bone were measured at each stage using a non-contact infrared thermometer. Results: There were no temperature increases above the initial temperature in any drilling procedure. The only significant difference between the non-slot and slot groups was observed with the use of the first drill in the MI group, with a higher temperature in the non-slot group (P=0.012). When the heat generation during the first and the second drilling was compared in the non-slot group, the heat generation during the first drilling was significantly higher (P<0.001), and there was no significant difference in heat generation between the drills in the slot group. Conclusions: Within the limitations of this study, implant-site preparation with the surgical guide showed no critical increase in the temperature of the cortical bone, regardless of whether there was a slot in the drill. In particular, the slotted drill had a cooling effect during the initial drilling.