Purpose: This study aimed to evaluate the long-term cumulative survival rate (CSR) of dental implants with micro-threads in the neck over a 10-year follow-up period and to examine the factors influencing the survival rate of dental implants. Methods: This retrospective study was based on radiographic and dental records. In total, 151 patients received 490 Oneplant ® dental implants with an implant neck micro-thread design during 2006–2010 in the Department of Periodontology of Seoul National University Dental Hospital. Implant survival was evaluated using Kaplan–Meier analysis. Cox proportional hazard regression analysis was used to identify the factors influencing implant failure. Results: Ten out of 490 implants (2.04%) failed due to fixture fracture. The CSR of the implants was 97.9%, and no significant difference was observed in the CSR between externaland internal-implant types (98.2% and 97.6%, respectively,P=0.670). In Cox regression analysis, 2-stage surgery significantly increased the risk of implant failure (hazard ratio: 4.769, P=0.039). There were no significant differences in influencing factors, including sex, age, implant diameter, length, fixture type, location, surgical procedure, bone grafting, and restoration type. Conclusions Within the limitations of this retrospective study, the micro-thread design of the implant neck was found to be favorable for implant survival, with stable clinical outcomes.

Purpose: This study investigated the adjunctive effect of light-emitting diodes (LEDs) in the treatment of experimental periodontitis. Methods: Experimental periodontitis was induced by placing ligatures around the mandibular second, third, and fourth premolars of 6 beagles for 3 months. After ligature removal, periodontitis progressed spontaneously for 2 months. The animals’ hemimandibles were allocated among the following 3 groups: 1) no treatment (control), 2) scaling and root planing (SRP), and 3) SRP with LED irradiation at 470-nm and 630-nm wavelengths (SRP/LED). The probing pocket depth (PPD) and gingival recession (GR) were measured at baseline, 6 weeks, and 12 weeks. The clinical attachment level (CAL) was calculated. After 12 weeks, histological and histomorphometric assessments were performed. The distances from the gingival margin to the apical extent of the junctional epithelium (E) and to the connective tissue (CT) attachment were measured, as was the total length of soft tissue (ST). Results: PPD and CAL increased at 12 weeks compared with baseline in the control group (6.31±0.43 mm to 6.93±0.50 mm, and 6.46±0.60 mm to 7.61±0.78 mm, respectively). PPD and CAL decreased at 12 weeks compared with baseline in the SRP group (6.01±0.59 to 4.81±0.65 mm, and 6.51±0.98 to 5.39±0.93 mm, respectively). PPD and CAL decreased at 12 weeks compared with baseline in the SRP/LED group (6.03±0.39 to 4.46±0.47 mm, and 6.11±0.47 to 4.78±0.57 mm, respectively). The E/ST and CT/ST ratios significantly differed among the 3 groups (P<0.05). The clinical parameters and histologic findings demonstrated that 470-nm and 630-nm wavelength LED irradiation accompanying SRP could improve treatment results. Conclusions Within the study limitations, 470 nm and 630 nm wavelength LED irradiation might provide additional benefits for periodontitis treatment.

Purpose: Endosseous titanium dental implants are widely regarded as the gold standard for replacing missing teeth. Despite the proven osseointegration of titanium implants, particularly those with enhanced surface modifications, concerns remain regarding esthetics, the risk of peri-implantitis, and potential hypersensitivity. Consequently, alternative materials, such as zirconia, have received increasing attention in recent years. This study evaluated the osseointegration parameters of zirconia implants placed in the mandibles of beagle dogs, as a preliminary in vivo evaluation of zirconia dental implants in South Korea. Materials and Methods: Seven 8-month-old beagle dogs underwent premolar extraction followed by placement of implants in the healed mandibular ridges. The following implants were used in this study: six turned-surface titanium implants, six rough-surface titanium implants, and six zirconia implants, following which the implants and surrounding tissues were harvested en bloc for histological analyses. Bone-to-implant contact (BIC) and new bone area (BA) percentages (%) were calculated and compared between the groups. Statistical analyses were conducted using ANOVA, with the significance level set at p < .05. Results: Histological analysis revealed no statistically significant difference in BIC between the rough-surface titanium and zirconia implants, although the turned-surface titanium implants exhibited significantly lower BIC than the other two groups (p < .05). No significant differences were found among the three groups in terms of BA. Conclusion The results of this study demonstrate that zirconia implants achieve BIC comparable to that of rough-surface titanium implants, suggestive of their potential clinical application.

Purpose: Endosseous titanium dental implants are widely regarded as the gold standard for replacing missing teeth. Despite the proven osseointegration of titanium implants, particularly those with enhanced surface modifications, concerns remain regarding esthetics, the risk of peri-implantitis, and potential hypersensitivity. Consequently, alternative materials, such as zirconia, have received increasing attention in recent years. This study evaluated the osseointegration parameters of zirconia implants placed in the mandibles of beagle dogs, as a preliminary in vivo evaluation of zirconia dental implants in South Korea. Materials and Methods: Seven 8-month-old beagle dogs underwent premolar extraction followed by placement of implants in the healed mandibular ridges. The following implants were used in this study: six turned-surface titanium implants, six rough-surface titanium implants, and six zirconia implants, following which the implants and surrounding tissues were harvested en bloc for histological analyses. Bone-to-implant contact (BIC) and new bone area (BA) percentages (%) were calculated and compared between the groups. Statistical analyses were conducted using ANOVA, with the significance level set at p < .05. Results: Histological analysis revealed no statistically significant difference in BIC between the rough-surface titanium and zirconia implants, although the turned-surface titanium implants exhibited significantly lower BIC than the other two groups (p < .05). No significant differences were found among the three groups in terms of BA. Conclusion The results of this study demonstrate that zirconia implants achieve BIC comparable to that of rough-surface titanium implants, suggestive of their potential clinical application.

Purpose: Endosseous titanium dental implants are widely regarded as the gold standard for replacing missing teeth. Despite the proven osseointegration of titanium implants, particularly those with enhanced surface modifications, concerns remain regarding esthetics, the risk of peri-implantitis, and potential hypersensitivity. Consequently, alternative materials, such as zirconia, have received increasing attention in recent years. This study evaluated the osseointegration parameters of zirconia implants placed in the mandibles of beagle dogs, as a preliminary in vivo evaluation of zirconia dental implants in South Korea. Materials and Methods: Seven 8-month-old beagle dogs underwent premolar extraction followed by placement of implants in the healed mandibular ridges. The following implants were used in this study: six turned-surface titanium implants, six rough-surface titanium implants, and six zirconia implants, following which the implants and surrounding tissues were harvested en bloc for histological analyses. Bone-to-implant contact (BIC) and new bone area (BA) percentages (%) were calculated and compared between the groups. Statistical analyses were conducted using ANOVA, with the significance level set at p < .05. Results: Histological analysis revealed no statistically significant difference in BIC between the rough-surface titanium and zirconia implants, although the turned-surface titanium implants exhibited significantly lower BIC than the other two groups (p < .05). No significant differences were found among the three groups in terms of BA. Conclusion The results of this study demonstrate that zirconia implants achieve BIC comparable to that of rough-surface titanium implants, suggestive of their potential clinical application.

Recent several reports have demonstrated that periodontitis is prevalent and adversely affects the survival in patients with chronic kidney disease (CKD) or end-stage kidney disease. However, its impact on transplant outcomes remains uncertain. Methods: This retrospective cohort study included 136 and 167 patients, respectively, who underwent living donor kidney transplantation (KT) at Seoul National University Hospital from July 2012 to August 2016 and Korea University Hospital from April 2008 to October 2018. We divided patients into three groups according to stages of periodontitis based on a new classification system. Results: Patients with severe periodontitis were older, had a higher prevalence of diabetes, a higher body mass index and C-reactive protein level, a lower cardiac output, and were more likely to be smokers, indicating its association with chronic systemic inflammation. After KT, stage IV periodontitis was independently associated with a lower incidence of acute T cell-mediated rejection, suggesting the possible effect of periodontitis on immune function. However, 1-year and 3-year estimated glomerular filtration rates were not different. Among the KT recipients followed up more than 3 years, new-onset cardiovascular disease occurred in nine patients, and coronary artery disease occurred more frequently in patients with stage IV periodontitis. However, diabetes was the independent predictor of new-onset coronary artery disease in multivariate logistic regression analysis. Conclusion: Our findings showed that periodontitis might be an important player in determining posttransplant outcomes in recipients. Further interventional trials to test whether treating periodontitis could modify transplant outcome are needed.

PURPOSE: Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. MATERIALS AND METHODS: Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. RESULTS: In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. CONCLUSION: The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.
Brain ; Carcinoma, Non-Small-Cell Lung ; Compliance ; Hippocampus ; Lung Neoplasms ; Neoplasm Metastasis ; Prospective Studies ; Radiation Oncology ; Radiotherapy

PURPOSE: Direct application of atmospheric-pressure plasma jets (APPJs) has been established as an effective method of microbial decontamination. This study aimed to investigate the bactericidal effect of direct application of an APPJ using helium gas (He-APPJ) on Porphyromonas gingivalis biofilms on sandblasted and acid-etched (SLA) titanium discs. METHODS: On the SLA discs covered by P. gingivalis biofilms, an APPJ with helium (He) as a discharge gas was applied at 3 different time intervals (0, 3, and 5 minutes). To evaluate the effect of the plasma itself, the He gas–only group was used as the control group. The bactericidal effect of the He-APPJ was determined by the number of colony-forming units. Bacterial viability was observed by confocal laser scanning microscopy (CLSM), and bacterial morphology was examined by scanning electron microscopy (SEM). RESULTS: As the plasma treatment time increased, the amount of P. gingivalis decreased, and the difference was statistically significant. In the SEM images, compared to the control group, the bacterial biofilm structure on SLA discs treated by the He-APPJ for more than 3 minutes was destroyed. In addition, the CLSM images showed consistent results. Even in sites distant from the area of direct He-APPJ exposure, decontamination effects were observed in both SEM and CLSM images. CONCLUSIONS: He-APPJ application was effective in removing P. gingivalis biofilm on SLA titanium discs in an in vitro experiment.
Bacterial Load ; Biofilms ; Decontamination ; Helium ; In Vitro Techniques ; Methods ; Microbial Viability ; Microscopy, Confocal ; Microscopy, Electron, Scanning ; Plasma Gases ; Plasma ; Porphyromonas gingivalis ; Porphyromonas ; Stem Cells ; Titanium

PURPOSE: The purpose of this retrospective study with 4–12 years of follow-up was to compare the marginal bone loss (MBL) between external-connection (EC) and internal-connection (IC) dental implants in posterior areas without periodontal or peri-implant disease on the adjacent teeth or implants. Additional factors influencing MBL were also evaluated. METHODS: This retrospective study was performed using dental records and radiographic data obtained from patients who had undergone dental implant treatment in the posterior area from March 2006 to March 2007. All the implants that were included had follow-up periods of more than 4 years after loading and satisfied the implant success criteria, without any peri-implant or periodontal disease on the adjacent implants or teeth. They were divided into 2 groups: EC and IC. Subgroup comparisons were conducted according to splinting and the use of cement in the restorations. A statistical analysis was performed using the Mann-Whitney U test for comparisons between 2 groups and the Kruskal-Wallis test for comparisons among more than 2 groups. RESULTS: A total of 355 implants in 170 patients (206 EC and 149 IC) fulfilled the inclusion criteria and were analyzed in this study. The mean MBL was 0.47 mm and 0.15 mm in the EC and IC implants, respectively, which was a statistically significant difference (P < 0.001). Comparisons according to splinting (MBL of single implants: 0.34 mm, MBL of splinted implants: 0.31 mm, P=0.676) and cement use (MBL of cemented implants: 0.27 mm, MBL of non-cemented implants: 0.35 mm, P=0.178) showed no statistically significant differences in MBL, regardless of the implant connection type. CONCLUSIONS: IC implants showed a more favorable bone response regarding MBL in posterior areas without peri-implantitis or periodontal disease.
Alveolar Bone Loss ; Dental Implant-Abutment Design ; Dental Implants ; Dental Records ; Follow-Up Studies ; Humans ; Peri-Implantitis ; Periodontal Diseases ; Retrospective Studies ; Splints ; Tooth

PURPOSE: The aim of this study was to evaluate the capacity of single and combined applications of the bark of the stems and roots of Magnolia officinalis Rehd. et Wils. (Magnoliae Cortex) and Zea mays L. (maize) to modulate inflammation in RAW 264.7 cells stimulated with Porphyromonas gingivalis. METHODS: RAW 264.7 cells were stimulated with P. gingivalis, and Magnoliae Cortex and/or maize was added. Cytotoxicity and the capacity to modulate inflammation were determined with a methylthiazol tetrazolium (MTT) assay, nitrite production, enzyme-linked immunosorbent assay (ELISA), and western blotting. RESULTS: Treatment with Magnoliae Cortex and/or maize inhibited nuclear transcription factor κB (NF-κB) pathway activation and nuclear p44/42 mitogen-activated protein kinase (MAPK) and inducible nitric oxide synthase (iNOS) protein expression in P. gingivalis-stimulated RAW 264.7 cells. Moreover, the treatments suppressed cytokines (prostaglandin E2 [PGE2], interleukin [IL]-1β, and IL-6) and nitrite production. CONCLUSIONS: Both Magnoliae Cortex and maize exerted an anti-inflammatory effect on P. gingivalis-stimulated RAW 264.7 cells, and this effect was more pronounced when the extracts were combined. These findings show that these extracts may be beneficial for slowing the progression of periodontal disease.
Blotting, Western ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Inflammation ; Interleukins ; Magnolia ; Mitogen-Activated Protein Kinase 3 ; Nitric Oxide Synthase Type II ; Periodontal Diseases ; Porphyromonas gingivalis ; Porphyromonas ; Protein Kinases ; RAW 264.7 Cells ; Transcription Factors ; Zea mays