• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.116-126
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• 2022

Purpose: This study evaluated the efficacy of treating periodontitis using subgingival nano-hydroxyapatite powder with an air abrasion device (NHAPA) combined with scaling and root planing (SRP). Methods: A total of 28 patients with stage III periodontitis (grade B) were included in this study, although 1 was lost during follow-up and 3 used antibiotics. The patients were divided into a test group and a control group. All patients first received whole-mouth SRP using hand instruments, and a split-mouth approach was used for the second treatment. In the test group, the teeth were treated with NHAPA for 15 seconds at 70% power per pocket. Subgingival plaque samples were obtained from the 2 deepest pockets at the test and control sites before treatment (baseline) and 3 months after treatment. The full-mouth plaque index (PI), gingival index (GI), papillary bleeding index (PBI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and at 1- and 3-month post-treatment. Real-time polymerase chain reaction was used to determine the colonisation of Treponema denticola (Td), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans in the subgingival plaque. Results: From baseline to the first month, the test group showed significantly larger changes in BOP and CAL (43.705%±27.495% and 1.160±0.747 mm, respectively) than the control group (36.311%±27.599% and 0.947±0.635 mm, respectively). Periodontal parameters had improved in both groups at 3 months. The reductions of PI, GI, BOP, PD, and CAL in the test group at 3 months were greater and statistically significant. The total bacterial count and Td and Pg species had decreased significantly by the third month in both groups (P<0.05). Conclusions: Applying NHAPA in addition to SRP improves clinical periodontal parameters more than SRP alone. Subgingival NHAPA may encourage clot adhesion to tooth surfaces by increasing surface wettability.

• The korean journal of orthodontics
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• v.51 no.3
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• pp.199-216
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• 2021

Objective: The aim of this systematic review was to evaluate the complications and side effects associated with the clinical use of orthodontic miniscrews by systematically reviewing the best available evidence. Methods: A survey of articles published up to March 2020 investigating the complications associated with miniscrew insertion, in both the maxilla and mandible, was performed using 7 electronic databases. Clinical studies, case reports, and case series reporting complications associated with the use of orthodontic miniscrew implants were included. Two authors independently performed study selection, data extraction, and risk-of-bias assessment. Results: The database survey yielded 24 articles. The risk-of-bias assessment revealed low methodological quality for the included studies. The most frequent adverse event reported was root injury with an associated periradicular lesion, vitality loss, pink discoloration of the tooth, and transitory loss of pulp sensitivity. Chronic inflammation of the soft tissue surrounding the miniscrew with mucosal overgrowth was also reported. The other adverse events reported were lesion of the buccal mucosa at the insertion site, soft-tissue necrosis, and perforation of the floor of the nasal cavity and maxillary sinus. Adverse events were also reported after miniscrew removal and included secondary bleeding, miniscrew fracture, scars, and exostosis. Conclusions: These findings highlight the need for clinicians to preliminarily assess generic and specific insertion site complications and side effects.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.3
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• pp.187-195
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• 2022

Background: This retrospective study investigated the incidence rate of accidental foreign body aspiration and ingestion according to patient sex, age, and dental department. This study aimed to verify whether the incidence rate is higher in geriatric than in younger patients and whether it is different among dental departments. Methods: Accidental foreign body aspiration and ingestion cases were collected from electronic health records and the safety report system of Yonsei University Dental Hospital from January 2011 to December 2017. The collected data included patients' age, sex, medical conditions, treatment procedures, and foreign objects that were accidentally aspirated or ingested. The incidence rate was calculated as the number of accidental foreign body aspirations and ingestions relative to the total number of patient visits. Differences depending on the patients' sex, age, and dental department were statistically identified. Results: There were 2 aspiration and 37 ingestion cases during the 7-year analysis period. The male to female incidence ratio was 2.8:1. The incidence rate increased with age and increased rapidly among those aged 80 years or older. Seven of the 37 patients with accidental foreign body ingestion had intellectual disability, Lou Gehrig's disease, dystonia, or oral and maxillofacial cancer. The incidence rate was highest in the Predoctoral Student Clinic and the Department of Prosthodontics. The most frequently swallowed objects were fixed dental prostheses and dental implant components. Conclusion: The incidence rate of accidental foreign body aspiration and ingestion differed according to patient sex, age, and dental department. Dental practitioners must identify high-risk patients and apply various methods to prevent accidental foreign body aspiration and ingestion in dental clinics. Inexperienced practitioners should be particularly careful.

• Journal of Veterinary Clinics
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• v.39 no.4
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• pp.185-191
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• 2022

An Amur softshell turtle with multiple shell injuries was admitted to the Seoul Wildlife Center on 19 May 2021. The most severe lesion was a puncture wound requiring urgent closure. In addition to routine supportive therapy, the damaged shell was patched with biocompatible polymethyl methacrylate (PMMA) materials (bone cement and dental acrylic) and fiberglass. Despite a few methods to repair the carapace or plastron of hard-shelled turtles, shell repair in the Amur softshell turtle has rarely been reported. This paper reports the repair process of a puncture wound in the carapace of a softshell turtle using polymethyl methacrylate (PMMA). PMMA is a biocompatible acrylic polymer that forms a tight structure that holds the implant against tissue defects, such as skin, bones, and dentures. Fiberglass, a preferred fiber in various medical fields, was used with PMMA to provide extra strength and waterproof capability. After the procedure, there were no signs of edema, inflammation, bleeding, skin discoloration, or any other complications. Accordingly, this can be a method of choice in softshell turtles using biocompatible materials to cover the lesion in the carapace and provide appropriate wound management, supportive therapy, and a suitable course of antibiotics considering all other circumstances.

• Journal of Periodontal and Implant Science
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• v.53 no.1
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• pp.54-68
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• 2023

Purpose: The purpose of this study was to determine whether metformin (MF) could alleviate the expresssion of reactive oxygen species (ROS) and improve the osteogenic ability of bone marrow mesenchymal stem cells derived from diabetic rats (drBMSCs) in vitro, and to evaluate the effect of MF on the ectopic osteogenesis of drBMSCs in a nude mouse model in vivo. Methods: BMSCs were extracted from normal and diabetic rats. In vitro, a cell viability assay (Cell Counting Kit-8), tests of alkaline phosphatase (ALP) activity, and western blot analysis were first used to determine the cell proliferation and osteogenic differentiation of drBMSCs that were subjected to treatment with different concentrations of MF (0, 50, 100, 200, 500 µM). The cells were then divided into 5 groups: (1) normal rat BMSCs (the BMSCs derived from normal rats group), (2) the drBMSCs group, (3) the drBMSCs + Mito-TEMPO (10 µM, ROS scavenger) group, (4) the drBMSCs + MF (200 µM) group, and (5) the drBMSCs + MF (200 µM) + H₂O₂ (50 µM, ROS activator) group. Intracellular ROS detection, a senescence-associated β-galactosidase assay, ALP staining, alizarin red staining, western blotting, and immunofluorescence assays were performed to determine the effects of MF on oxidative stress and osteogenic differentiation in drBMSCs. In vivo, the effect of MF on the ectopic osteogenesis of drBMSCs was evaluated in a nude mouse model. Results: MF effectively reduced ROS levels in drBMSCs. The cell proliferation, ALP activity, mineral deposition, and osteogenic-related protein expression of drBMSCs were demonstrably higher in the MF-treated group than in the non-MF-treated group. H₂O₂ inhibited the effects of MF. In addition, ectopic osteogenesis was significantly increased in drBMSCs treated with MF. Conclusions: MF promoted the proliferation and osteogenic differentiation of drBMSCs by inhibiting the oxidative stress induced by diabetes and enhenced the ectopic bone formation of drBMSCs in nude mice.

• Korean Journal of Materials Research
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• v.33 no.8
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• pp.337-343
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• 2023

3Y-TZP (3 mol% yttria-stabilized tetragonal zirconia polycrystals) ceramics have excellent mechanical properties including high fracture toughness, good abrasion resistance as well as chemical and biological stability. As a result, they are widely used in mechanical and medical components such as bearings, grinding balls, and hip implants. In addition, they provide excellent light transmittance, biocompatibility, and can match tooth color when used as a dental implant. Recently, given the materials' resemblance to human teeth, these ceramics have emerged as an alternative to titanium implants. Since the introduction of CAD/CAM in the manufacture of ceramic implants, they've been increasingly used for prosthetic restoration where aesthetics and strength are required. In this study, to improve the surface roughness of zirconia implants, we modified the 3Y-TZP surface with a biocomposite of hydroxyapatite and forsterite using room temperature spray coating methods, and investigated the mixed effect of the two powders on the evolution of surface microstructure, i.e., coating thickness and roughness, and biological interaction during the in vitro test in SBF solution. We compared improvement in bioactivity by observing dissolution and re-precipitation on the specimen surface. From the results of in vitro testing in SBF solution, we confirmed improvement in the bioactivity of the 3Y-TZP substrate after surface modification with a biocomposite of hydroxyapatite and forsterite. Surface dissolution of the coating layer and the precipitation of new hydroxyapatite particles was observed on the modified surface, indicating the improvement in bioactivity of the zirconia substrate.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.1.1-1.13
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• 2021

Objectives: The aim of this study was to evaluate the dystrophic mineralization deposits from 3 calcium silicate-based cements (Micro-Mega mineral trioxide aggregate [MM-MTA], Biodentine [BD], and EndoSequence Root Repair Material [ESRRM] putty) over time after subcutaneous implantation into rats. Materials and Methods: Forty-five silicon tubes containing the tested materials and 15 empty tubes (serving as a control group) were subcutaneously implanted into the backs of 15 Wistar rats. At 1, 4, and 8 weeks after implantation, the animals were euthanized (n = 5 animals/group), and the silicon tubes were removed with the surrounding tissues. Histopathological tissue sections were stained with von Kossa stain to assess mineralization. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX) were also used to assess the chemical components of the surface precipitates deposited on the implant and the pattern of calcium and phosphorus distribution at the material-tissue interface. The calcium-to-phosphorus ratios were compared using the non-parametric Kruskal-Wallis test at a significance level of 5%. Results: The von Kossa staining showed that both BD and ESRRM putty induced mineralization starting at week 1; this mineralization increased further until the end of the study. In contrast, MM-MTA induced dystrophic calcification later, from 4 weeks onward. SEM/EDX showed no statistically significant differences in the calcium- and phosphorus-rich areas among the 3 materials at any time point (p > 0.05). Conclusions: After subcutaneous implantation, biomineralization of the 3-calcium silicate-based cements started early and increased over time, and all 3 tested cements generated calcium- and phosphorus-containing surface precipitates.

• Journal of Periodontal and Implant Science
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• v.53 no.3
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• pp.184-193
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• 2023

Purpose: The present study was designed to compare the incidence of periodontitis according to menopausal status and to investigate the possible effect of hormone replacement therapy (HRT) on periodontitis in postmenopausal women using a common data model (CDM) at a single institution. Methods: This study involved retrospective cohort data of 950,751 patients from a 20-year database (2001 to 2020) of Ewha Womans University Mokdong Hospital converted to the Observational Medical Outcomes Partnership CDM. One-way analysis of variance models and the χ² test were used to analyze the statistical differences in patient characteristics among groups. A time-dependent Cox regression analysis was used to calculate hazard ratios and 95% confidence intervals, and P values less than 0.05 were considered to indicate statistical significance. Results: Of the 29,729 patients, 1,307 patients were diagnosed with periodontitis and 28,422 patients were not. Periodontitis was significantly more common among postmenopausal patients regardless of HRT status than among the non-menopausal group (P<0.05). Time-dependent Cox regression analysis showed that the postmenopausal patients had a significantly higher chance of having periodontitis than non-menopausal patients (P<0.05), but after adjustment for age, body mass index, and smoking status, the difference between the non-menopausal and post-menopausal HRT-treated groups was insignificant (P=0.140). Conclusions: Postmenopausal women had a significantly greater risk of periodontitis than non-menopausal women. Additionally, the use of HRT in postmenopausal women could reduce the incidence of periodontitis.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.103-114
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• 2024

Objective : Decompressive craniectomy (DC) with duroplasty is one of the common surgical treatments for life-threatening increased intracranial pressure (ICP). Once ICP is controlled, cranioplasty (CP) with reinsertion of the cryopreserved autologous bone flap or a synthetic implant is considered for protection and esthetics. Although with the risk of autologous bone flap resorption (BFR), cryopreserved autologous bone flap for CP is one of the important material due to its cost effectiveness. In this article, we performed conventional statistical analysis and the machine learning technique understand the risk factors for BFR. Methods : Patients aged >18 years who underwent autologous bone CP between January 2015 and December 2021 were reviewed. Demographic data, medical records, and volumetric measurements of the autologous bone flap volume from 94 patients were collected. BFR was defined with absolute quantitative method (BFR-A) and relative quantitative method (BFR%). Conventional statistical analysis and random forest with hyper-ensemble approach (RF with HEA) was performed. And overlapped partial dependence plots (PDP) were generated. Results : Conventional statistical analysis showed that only the initial autologous bone flap volume was statistically significant on BFR-A. RF with HEA showed that the initial autologous bone flap volume, interval between DC and CP, and bone quality were the factors with most contribution to BFR-A, while, trauma, bone quality, and initial autologous bone flap volume were the factors with most contribution to BFR%. Overlapped PDPs of the initial autologous bone flap volume on the BRF-A crossed at approximately 60 mL, and a relatively clear separation was found between the non-BFR and BFR groups. Therefore, the initial autologous bone flap of over 60 mL could be a possible risk factor for BFR. Conclusion : From the present study, BFR in patients who underwent CP with autologous bone flap might be inevitable. However, the degree of BFR may differ from one to another. Therefore, considering artificial bone flaps as implants for patients with large DC could be reasonable. Still, the risk factors for BFR are not clearly understood. Therefore, chronological analysis and pathophysiologic studies are needed.

• Journal of Periodontal and Implant Science
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• v.53 no.6
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• pp.429-443
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• 2023

Purpose: The aim of this study was to determine 1) the bone-regenerative effect of porcine bone block materials with or without collagen matrix incorporation, 2) the effect of a collagen barrier, and 3) the effect of adding recombinant human bone morphogenetic protein-2 (rhBMP-2) to the experimental groups. Methods: Four treatment modalities were applied to rabbit calvaria: 1) deproteinized bovine bone mineral blocks (DBBM), 2) porcine bone blocks with collagen matrix incorporation (PBC), 3) porcine bone blocks alone without collagen matrix incorporation (PB), and 4) PBC blocks covered by a collagen membrane (PBC+M). The experiments were repeated with the addition of rhBMP-2. The animals were sacrificed after either 2 or 12 weeks of healing. Micro-computed tomography (micro-CT), histologic, and histomorphometric analyses were performed. Results: Micro-CT indicated adequate volume stability in all block materials. Histologically, the addition of rhBMP-2 increased the amount of newly formed bone (NB) in all the blocks. At 2 weeks, minimal differences were noted among the NB of groups with or without rhBMP-2. At 12 weeks, the PBC+M group with rhBMP-2 presented the greatest NB (P<0.05 vs. the DBBM group with rhBMP-2), and the PBC and PB groups had greater NB than the DBBM group (P>0.05 without rhBMP-2, P<0.05 with rhBMP-2). Conclusions: The addition of rhBMP-2 enhanced NB formation in vertical augmentation using bone blocks, and a collagen barrier may augment the effect of rhBMP-2.