Quantitative analysis of periodontal pathogens present in the saliva of geriatric subjects

Shet, Uttom K.,Oh, Hee-Kyun,Kim, Hye-Jeong,Chung, Hyun-Ju,Kim, Young-Joon,Kim, Ok-Su,Choi, Hong-Ran,Kim, Ok-Jun,Lim, Hoi-Jeong,Lee, Seok-Woo Korean Academy of Periodontology 2013 Journal of Periodontal & Implant Science Vol.43 No.4

Purpose: At present, information regarding periodontal disease in geriatric patients is scarce. The purpose of this study was to quantify the periodontal pathogens present in the saliva of Korean geriatric patients and assess the relationship between the bacterial levels and the periodontal condition. Methods: Six putative periodontal pathogens were quantified by using a real-time polymerase chain reaction assay in geriatric patient groups (>60 years) with mild chronic periodontitis (MCP), moderate chronic periodontitis (MoCP), and severe chronic periodontitis (SCP). The copy numbers of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Prevotella intermedia were measured. Results: It was found that the bacterial copy numbers increased as the severity of the disease increased from MCP to SCP, except for P. intermedia. For P. intermedia, it was found that samples in the MCP group yielded the largest amount. It was also found that the quantities of P. gingivalis, T. forsythia, and T. denticola, the so-called "red complex" bacteria, were lower than those of F. nucleatum, A. actinomycetemcomitans, and P. intermedia in all of the samples. Conclusions: Collectively, the results of this study suggest that the levels of P. gingivalis, T. forsythia, F. nucleatum, and T. denticola present in saliva are associated with the severity of periodontal disease in geriatric patients.

Synthesis and characterization of band gap-reduced ZnO:N and ZnO:(Al,N) films for photoelectrochemical water splitting

Shet, Sudhakar,Ahn, Kwang-Soon,Deutsch, Todd,Wang, Heli,Ravindra, Nuggehalli,Yan, Yanfa,Turner, John,Al-Jassim, Mowafak Cambridge University Press (Materials Research Soc 2010 Journal of materials research Vol.25 No.1

<P>ZnO thin films with significantly reduced band gaps were synthesized by doping N and codoping Al and N at 100 °C. All the films were synthesized by radiofrequency magnetron sputtering on F-doped tin-oxide-coated glass. We found that codoped ZnO:(Al,N) thin films exhibited significantly enhanced crystallinity compared with ZnO doped solely with N, ZnO:N, at the same growth conditions. Furthermore, annealed ZnO:(Al,N) thin films exhibited enhanced N incorporation over ZnO:N films. As a result, ZnO:(Al,N) films exhibited better photocurrents than ZnO:N films grown with pure N doping, suggesting that charge-compensated donor-acceptor codoping could be a potential method for band gap reduction of wide-band gap oxide materials to improve their photoelectrochemical performance.</P>

Effects of substrate temperature and RF power on the formation of aligned nanorods in ZnO thin films

Shet, Sudhakar,Ahn, Kwang-Soon,Nuggehalli, Ravindra,Yan, Yanfa,Turner, John,Al-Jassim, Mowafak Springer-Verlag 2010 JOM Vol.62 No.6

Humoral immune responses to periodontal pathogens in the elderly

Shet, Uttom,Oh, Hee-Kyun,Chung, Hyun-Ju,Kim, Young-Joon,Kim, Ok-Su,Lim, Hoi-Jeong,Shin, Min-Ho,Lee, Seok-Woo Korean Academy of Periodontology 2015 Journal of Periodontal & Implant Science Vol.45 No.5

Purpose: Elderly people are thought to be more susceptible to periodontal disease due to reduced immune function associated with aging. However, little information is available on the nature of immune responses against putative periodontal pathogens in geriatric patients. The purpose of this study was to evaluate the serum IgG antibody responses to six periodontal pathogens in geriatric subjects. Methods: The study population consisted of 85 geriatric patients and was divided into three groups: 29 mild (MCP), 27 moderate (MoCP), and 29 severe (SCP) chronic periodontitis patients. Serum levels of IgG antibody to Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Prevotella intermedia were measured by enzyme-linked immunosorbent assay (ELISA) and compared among the groups. Results: All three groups showed levels of serum IgG in response to P. gingivalis, A. actinomycetemcomitans, and P. intermedia that were three to four times higher than levels of IgG to T. forsythia, T. denticola, and F. nucleatum. There were no significant differences among all three groups in IgG response to P. gingivalis (P=0.065), T. forsythia (P=0.057), T. denticola (P=0.1), and P. intermedia (P=0.167), although the IgG levels tended to be higher in patients with SCP than in those with MCP or MoCP (with the exception of those for P. intermedia). In contrast, there were significant differences among the groups in IgG levels in response to F. nucleatum (P=0.001) and A. actinomycetemcomitans (P=0.003). IgG levels to A. actinomycetemcomitans were higher in patients with MCP than in those with MoCP or SCP. Conclusions: When IgG levels were compared among three periodontal disease groups, only IgG levels to F. nucleatum significantly increased with the severity of disease. On the contrary, IgG levels to A. actinomycetemcomitans decreased significantly in patients with SCP compared to those with MCP. There were no significant differences in the IgG levels for P. gingivalis, T. forsythia, T. denticola, and P. intermedia among geriatric patients with chronic periodontitis.

Humoral immune responses to periodontal pathogens in the elderly

Uttom Shet,오희균,정현주,김영준,김옥수,임회정,신민호,이석우 대한치주과학회 2015 Journal of Periodontal & Implant Science Vol.45 No.5

Purpose: Elderly people are thought to be more susceptible to periodontal disease due to reduced immune function associated with aging. However, little information is available on the nature of immune responses against putative periodontal pathogens in geriatric pa¬tients. The purpose of this study was to evaluate the serum IgG antibody responses to six periodontal pathogens in geriatric subjects. Methods: The study population consisted of 85 geriatric patients and was divided into three groups: 29 mild (MCP), 27 moderate (MoCP), and 29 severe (SCP) chronic periodonti¬tis patients. Serum levels of IgG antibody to Porphyromonas gingivalis, Tannerella forsyth¬ia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nuclea¬tum, and Prevotella intermedia were measured by enzyme-linked immunosorbent assay (ELISA) and compared among the groups. Results: All three groups showed levels of serum IgG in response to P. gingivalis, A. actino-mycetemcomitans, and P. intermedia that were three to four times higher than levels of IgG to T. forsythia, T. denticola, and F. nucleatum. There were no significant differences among all three groups in IgG response to P. gingivalis (P=0.065), T. forsythia (P=0.057), T. denticola (P=0.1), and P. intermedia (P=0.167), although the IgG levels tended to be high¬er in patients with SCP than in those with MCP or MoCP (with the exception of those for P. intermedia). In contrast, there were significant differences among the groups in IgG levels in response to F. nucleatum (P=0.001) and A. actinomycetemcomitans (P=0.003). IgG lev¬els to A. actinomycetemcomitans were higher in patients with MCP than in those with MoCP or SCP. Conclusions: When IgG levels were compared among three periodontal disease groups, only IgG levels to F. nucleatum significantly increased with the severity of disease. On the contrary, IgG levels to A. actinomycetemcomitans decreased significantly in patients with SCP compared to those with MCP. There were no significant differences in the IgG levels for P. gingivalis, T. forsythia, T. denticola, and P. intermedia among geriatric patients with chronic periodontitis.

Quantitative analysis of periodontal pathogens present in the saliva of geriatric subjects

Uttom K. Shet,오희균,김혜정,정현주,김영준,김옥수,최홍란,김옥준,임회정,이석우 대한치주과학회 2013 Journal of Periodontal & Implant Science Vol.43 No.4

Purpose: At present, information regarding periodontal disease in geriatric patients is scarce. The purpose of this study was to quantify the periodontal pathogens present in the saliva of Korean geriatric patients and assess the relationship between the bacterial levels and the periodontal condition. Methods: Six putative periodontal pathogens were quantified by using a real-time polymerase chain reaction assay in geriatric patient groups (>60 years) with mild chronic periodontitis (MCP), moderate chronic periodontitis (MoCP), and severe chronic periodontitis (SCP). The copy numbers of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Prevotella intermedia were measured. Results: It was found that the bacterial copy numbers increased as the severity of the disease increased from MCP to SCP, except for P. intermedia. For P. intermedia, it was found that samples in the MCP group yielded the largest amount. It was also found that the quantities of P. gingivalis, T. forsythia, and T. denticola, the so-called “red complex” bacteria, were lower than those of F. nucleatum, A. actinomycetemcomitans, and P. intermedia in all of the samples. Conclusions: Collectively, the results of this study suggest that the levels of P. gingivalis, T. forsythia, F. nucleatum, and T. denticola present in saliva are associated with the severity of periodontal disease in geriatric patients.

수직 치조골 신장술 후 증대된 치조골과 임플란트의 예후 평가

Uttom Kumar Shet,국민석(Min-Suk Kook),정승곤(Seunggon Jung),오희균(Hee-Kyun Oh) 대한구강악안면외과학회 2011 대한구강악안면외과학회지 Vol.37 No.5

Introduction: The purpose of this study was to evaluate the clinical result of vertical alveolar distraction, especially the distracted alveolar bone and installed implants. Materials and Methods: Twenty-one patients who have been received the vertical alveolar distraction and implant installation on 22 areas (3 maxilla and 19 mandible) using intraoral alveolar distraction device were examined. After consolidation period of 3-4 months, distraction devices were removed and 91 implants were installed in the distracted alveolar bone. The distracted bone and implants were evaluated clinically and radiographically. Results: Mean height of distracted alveolar bone was 7.5±3.2 mm (range: 2.5-15.0 mm). Mean follow-up period after completion of the distraction was 3.1 years (range: 1.4-11.5 years). Mean resorption of distracted alveolar bone was 1.6±1.8 mm. The success and survival rates of implants was 95.3% and 100%, respectively.. Conclusion: Results of this study indicate that vertical alveolar distraction procedure is a useful and stable method for alveolar ridge augmentation and implantation.

자가 온레이 블럭골 이식 후 증대된 치조골과 임플란트의 평가

Uttom Kumar Shet,조민성(Min-Sung Cho),허정우(Jung-Woo Hur),오철중(Chul-Jung Oh),정광(Kwang Chung),박홍주(Hong-Ju Park),국민석(Min-Suk Kook),정승곤(Seung-Gon Jung),오희균(Hee-Kyun Oh) 대한치과의사협회 2012 대한치과의사협회지 Vol.50 No.6

Introduction: The purpose of this study is to evaluate the clinical results of vertical alveolar ridge augmentation using autogenous block bone graft, especially resorption rate, and outcomes of dental implants placed in the grafted site. Patients and Methods: Medical records and radiographs were reviewed. Twenty-seven patients who have been received the autogenous block bone graft which harvested from chin, ramus, and ilium, and the implant installation on 31 areas(22 maxillas and 9 mandibles) were included. Eight implants were installed simultaneously at the time of bone graft in 4 patients, and 65 implants were installed after 4.9 months(range 2~18 months) of autogenous block bone graft in 23 patients. The resorption amount and rate of augmented bone, and the success and survival rates implants were evaluated. Results: Mean height of the augmented block bone was 5.9??2.3 ㎜(range from 2.5 to 13.0 mm). Mean follow-up period after block bone graft was 30.4 months(range from 16 to 55 months). Mean resorption of the augmented block bone was 2.0??1.5 ㎜ (range from 0.5 to 7.24 ㎜). The success and survival rates of the implants were 78.1% and 98.6%, respectively. Conclusion: This study indicates that the autogenous block bone graft is a useful and stable method for alveolar ridge augmentation for dental implant. And more augmentation is needed to compensate the resorption of the grafted bone.

Amorphous copper tungsten oxide with tunable band gaps

Chen, Le,Shet, Sudhakar,Tang, Houwen,Ahn, Kwang-soon,Wang, Heli,Yan, Yanfa,Turner, John,Al-Jassim, Mowafak American Institute of Physics 2010 JOURNAL OF APPLIED PHYSICS - Vol.108 No.4

Identification of Enterococcus faecalis antigens specifically expressed in vivo

이석우,Uttom K. Shet,박상원,임현필,윤귀덕,강성수,김세은 대한치과보존학회 2015 Restorative Dentistry & Endodontics Vol.40 No.4

Objectives: Molecular mechanism of the pathogenicity of Enterococcus faecalis (E. faecalis), a suspected endodontic pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here we report the identification of in vivo expressed antigens of E. faecalis by using a novel immunoscreening technique called change-mediated antigen technology (CMAT) and an experimental animal model of endodontic infection. Materials and Methods: Among 4,500 E. coli recombinant clones screened, 19 positive clones reacted reproducibly with hyperimmune sera obtained from rabbits immunized with E. faecalis cells isolated from an experimental endodontic infection. DNA sequences from 16 of these in vivo-induced (IVI) genes were determined. Results: Identified protein antigens of E. faecalis included enzymes involved in housekeeping functions, copper resistance protein, putative outer membrane proteins, and proteins of unknown function. Conclusions: In vivo expressed antigens of E. faecalis could be identified by using a novel immune-screening technique CMAT and an experimental animal model of endodontic infection. Detailed analysis of these IVI genes will lead to a better understanding of the molecular mechanisms involved in the endodontic infection of E. faecalis.