Knowledge and attitudes of Korean dentists towards human immunodeficiency virus/acquired immune deficiency syndrome

PURPOSE: Infection with human immunodeficiency virus (HIV) remains a major global threat, and although the prevalence is comparatively still very low, the number of HIV-positive Koreans is increasing. However, there are no official guidelines as to how to treat people living with HIV/acquired immunodeficiency syndrome (AIDS) (PLWHA) or how to screen for potentially infectious people. This study assessed the level of knowledge and attitudes of dentists in Korea toward PLWHA, and their attitudes to screening patients for HIV infections. METHODS: A cross-sectional prospective survey targeting dentists working in Korea was conducted using a self-administered questionnaire. RESULTS: A satisfactory level of knowledge about HIV/AIDS and a relatively positive attitude toward PLWHA was found. Most of the respondents preferred rapid HIV testing using oral fluid as a specimen. The general attitude of dentists toward HIV/AIDS is sufficiently positive to enable provision of the best treatment to the patients in need. CONCLUSIONS: Most of the dentists require HIV testing in dental clinics. In spite of their needs, there are several obstacles. It is hoped that financial considerations and official legal requirements related to HIV testing strategies will be considered.ope

Novel analysis model for implant osseointegration using ectopic bone formation via the recombinant human bone morphogenetic protein-2/macroporous biphasic calcium phosphate block system in rats: a proof-of-concept study.

PURPOSE: The osseointegration around titanium mini-implants installed in macroporous biphasic calcium phosphate (MBCP) blocks was evaluated after incubation with recombinant human bone morphogenetic protein-2 (rhBMP-2) in an ectopic subcutaneous rat model. METHODS: Mini-implants (φ1.8×12 mm) were installed in MBCP blocks (bMBCPs, 4×5×15 mm) loaded with rhBMP-2 at 0.1 mg/mL, and then implanted for 8 weeks into subcutaneous pockets of male Sprague-Dawley rats (n=10). A histomorphometric analysis was performed, and the bone-to-implant contact (BIC) and bone density were evaluated. RESULTS: Significant osteoinductive activity was induced in the rhBMP-2/bMBCP group. The percentage of BIC was 41.23±4.13% (mean±standard deviation), while bone density was 33.47±5.73%. In contrast, no bone formation was observed in the bMBCP only group. CONCLUSIONS: This model represents a more standardized tool for analyzing osseointegration and bone healing along the implant surface and in bMBCPs that excludes various healing factors derived from selected animals and defect models.ope

Histological characteristics of newly formed cementum in surgically created one-wall intrabony defects in a canine model

PURPOSE: Periodontal regenerative therapies for defects created by severe periodontitis are mainly focused on bone regeneration. Although cementum regeneration needs to be better understood, it is believed to play an important role in periodontal regeneration. The first step toward a full understanding of cementum regeneration is to compare repaired cementum to pristine cementum. This study, which used histological techniques, was designed to focus on cementum regeneration and to compare pristine cementum to repaired cementum after surgical procedures with 8 and 24 week healing periods in a canine model. 0aMETHODS: Buccal and lingual mucoperiosteal flaps of 10 beagle dogs were surgically reflected to create critical-sized defects. Intrabony one-wall defects, of which dimension is 4 mm width and 5 mm depth, were made at the distal aspect of mandibular second premolars and the mesial aspect of mandibular fourth premolars in the right and left jaw quadrants. Animals were sacrificed after 8 and 24 weeks post-surgery for histological specimen preparation and histometric analysis. 0aRESULTS: The repaired cementum was composed mostly of acellular cementum and cellular mixed fiber cementum and was thicker in the apical area than in the coronal area. The acellular cementum of the supracrestal area appeared to be amorphous. The newly formed cellular cementum was partially detached from the underlying circumpulpal dentin, which implied a weak attachment between new cementum and dentin, and this split was observed to a lesser extent in the 24 week group than in the 8 week group. The vertical height of the repaired cementum was greater in the 24 week group than in the 8 week group. 0aCONCLUSIONS: Within the limitations of this study, we can conclude that repaired cementum after root planing was mainly acellular cementum and cementum tissue that matured to a shape similar to pristine cementum as the healing progressed from 8 to 24 weeksope

Development of the implant surgical technique and assessment rating system

PURPOSE: There has been no attempt to establish an objective implant surgical evaluation protocol to assess residents' surgical competence and improve their surgical outcomes. The present study presents a newly developed assessment and rating system and simulation model that can assist the teaching staffs to evaluate the surgical events and surgical skills of residents objectively. METHODS: Articles published in peer-reviewed English journals were selected using several scientific databases and subsequently reviewed regarding surgical competence and assessment tools. Particularly, medical journals reporting rating and evaluation protocols for various types of medical surgeries were thoroughly analyzed. Based on these studies, an implant surgical technique assessment and rating system (iSTAR) has been developed. Also, a specialized dental typodont was developed for the valid and reliable assessment of surgery. RESULTS: The iSTAR consists of two parts including surgical information and task-specific checklists. Specialized simulation model was subsequently produced and can be used in combination with iSTAR. CONCLUSIONS: The assessment and rating system provided may serve as a reference guide for teaching staffs to evaluate the residents' implant surgical techniques.ope

In situ dental implant installation after decontamination in a previously peri-implant diseased site: a pilot study

PURPOSE: The aim of this study was to examine whether a previous peri-implantitis site can affect osseointegration, by comparing implant placement at a site where peri-implantitis was present and at a normal bone site. A second aim of this study was to identify the tissue and bone reaction after treating the contaminated implant surface to determine the optimal treatment for peri-implant diseases. METHODS: A peri-implant mucositis model for dogs was prepared to determine the optimal treatment option for peri-implant mucositis or peri-implantitis. The implants were inserted partially to a length of 6 mm. The upper 4 mm part of the dental implants was exposed to the oral environment. Simple exposure for 2 weeks contaminated the implant surface. After 2 weeks, the implants were divided into three groups: untreated, swabbed with saline, and swabbed with H(2)O(2). Three implants from each group were placed to the full length in the same spot. The other three implants were placed fully into newly prepared bone. After eight weeks of healing, the animals were sacrificed. Ground sections, representing the mid-buccal-lingual plane, were prepared for histological analysis. The analysis was evaluated clinically and histometrically. RESULTS: The untreated implants and H(2)O(2)-swabbed implants showed gingival inflammation. Only the saline-swabbed implant group showed re-osseointegration and no gingival inflammation. There was no difference in regeneration height or bone-to-implant contact between in situ implant placement and implant placement in the new bone site. CONCLUSIONS: It can be concluded that cleaning with saline may be effective in implant decontamination. After implant surface decontamination, implant installation in a previous peri-implant diseased site may not interfere with osseointegration.ope

Comparative evaluation of roughness of titanium surfaces treated by different hygiene instruments

PURPOSE: The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. METHODS: Thirty-seven identical disks (5 mm in diameter) were investigated in this study. The specimens were divided into eight groups according to the types of instrumentation and the angle of application. Ultrasonic scaling systems were applied on a titanium disk to simulate standard clinical conditions. The equipment included a piezoelectric ultrasonic scaler with a newly developed metallic tip (NS group), a piezoelectric ultrasonic scaler with a conventional tip (CS group), a piezoelectric root planer ultrasonic scaler with a conventional tip (PR group), and a plastic hand curette (PH group). In addition, the sites treated using piezoelectric ultrasonic scaler systems were divided two sub-groups: 15 and 45 degrees. The treated titanium surfaces were observed by scanning electron microscopy (SEM), and the average surface roughness (Ra) and mean roughness profile depth (Rz) were measured with a profilometer. RESULTS: SEM no significant changes in the titanium surfaces in the NS group, regardless of the angle of application. The PH group also showed no marked changes to the titanium surface, although some smoothening was observed. All CS and PR sites lost their original texture and showed irregular surfaces in SEM analysis. The profilometer analysis demonstrated that the roughness values (Ra and Rz) of the titanium surfaces increased in all, except the PH and NS groups, which showed roughness decreases relative to the untreated control group. The Ra value differed significantly between the NS and PR groups (P<0.05). CONCLUSIONS: The results of this study indicated that changes in or damage to titanium surfaces might be more affected by the hardness of the scaler tip than by the application method. Within the limitations of this study, the newly developed metallic scaler tip might be especially suitable for peri-implant surface decontamination, due to its limited effects on the titanium surface.ope

Periodontal regenerative effect of a bovine hydroxyapatite/collagen block in one-wall intrabony defects in dogs: a histometric analysis

PURPOSE: The aim of this study was to elucidate the effect of a bovine hydroxyapatite/collagen (BHC) block in one-wall intrabony periodontal defects in dogs. METHODS: A one-wall intrabony periodontal defect (4 mm wide and 5 mm deep) was prepared bilaterally at the mesial side of the mandibular fourth premolar in five beagle dogs. After thorough root planing, block-type BHC (4×5×5 mm) was placed on one side. The contralateral defect area did not receive any material as a sham-surgery control. Histological analysis of the sites was performed after an 8-week healing period. RESULTS: Two of five samples in the experimental group healed well without dissipation of the graft materials, and histological analysis revealed excellent regeneration of the periodontal tissues. However, most of the grafted materials had been displaced in the other three samples, leaving only a small portion of the graft. The measured parameters exhibited large standard deviations, and the mean values did not differ significantly between the experimental and sham-surgery control sides. CONCLUSIONS: The application of BHC alone-without a barrier membrane-to wide, one-wall intrabony periodontal defects yielded inconsistent results regarding both periodontal regeneration and substantivity of the graft materials. Thus, the use of a barrier membrane for noncontained-type defects is recommended to improve the stability of the grafted material, and to condense it.ope

Early Implant Placement in the Esthetic Zone with Hard Tissue and Soft Tissue Augmentation

Early implant placement is one of the treatment options for postextraction rehabilitation in the anterior region. Implant placement to replace a single tooth in the esthetic zone is challenging to the clinician, particularly in sites with soft tissue or bone deficiency. This report describes an early implant placement in the esthetic zone, with hard tissue and soft tissue augmentation, providing favorable esthetic outcome on the facial gingival and interdental gingiva height. However, long-term follow up results should be studied.ope

사람치주인대의 염증성 조직에서 분리된 사람 치주인대줄기세포의 in vitro 및 in vivo 분석

Dept. of Dental Science/박사Mesenchymal stem cells could be isolated from healthy periodontal ligaments (PDL). The aims of this study were to isolate and characterize human PDL stem cells (hPDLSCs) from inflamed PDL tissue, and to evaluate their regenerative potential.Inflamed hPDLSCs (ihPDLSCs) were isolated from the inflamed PDL tissue obtained from intrabony defects during flap surgery, and characterized by immunohistochemical staining, colony-forming-unit assay, fluorescence-activated cell-sorting, cell surface antigens, and mRNA expression in comparison to healthy hPDLSCs obtained from extracted teeth for orthodontic purpose. The proliferative potential and migratory potential was assessed, and compared to healthy hPDLSCs. Regenerative potential was assessed by an in vivo ectopic transplantation model.ihPDLSCs were successfully isolated and characterized as mesenchymal stem cells. In vitro osteogenic/cementogenic and adipogenic potentials of ihPDLSCs were similar to those of hPDLSCs. The proliferative potential did not differ between healthy hPDLSCs and ihPDLSCs, while the migratory capacity was significantly increased in ihPDLSCs (p < 0.05). Both groups exhibited new cementum-like tissue and related PDL fiber regeneration in an in vivo transplantation model.ihPDLSCs could be successfully isolated from inflamed PDL tissue, and they retained the regenerative potential for cementum and related PDL tissues.restrictio

모바일 기기의 적응형 메뉴를 위한 사용자-시스템 협력 방안

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