Transforming growth factor-ss1 accelerates resorption of a calcium carbonate biomaterial in periodontal defects

Dept. of Dental Science/박사[한글]변환 성장 유도 단백질인 Tranforming growth factor-ss1은 다양한 종류의세포들의 성장, 분화, 및 세포 기질의 생성에 관여한다고 알려져 왔다. 또,골모 세포들의 초기 생성에도 Tranforming growth factor-ss1 단백질이 활발하게 관여한다고 보고된 바 있어 TGF- ss1을 사용한 치주조직치유나 재생 실험들이 많이 진행되고 있다. 예전의 실험에서, Tranforming growth factor- ss1을calcium carbonate 운반체를 이용하여 상치조 결손부에 적용한 후 차폐막으로 덮고 골 형성에 어떤 영향을 미치는지 실험하였다. 대조군(control group)에서는 TGF-ss1을 적용하지 않은 채 Biocoral 운반체와 차폐막만 사용하였다.결과를 살펴보면 두 실험 군 간에 새롭게 생성된 골의 양이나 수직적인 높이에 있어서 유의성 있는 차이가 없었다. 이는 TGF- ss1이 본 상치조 결손부에서 치주조직재생에 부가적인 영향이 없는 것으로 해석될 수 있으나 몇가지 의문점을 남기게 되었다. 본 연구에서는 이러한 의문점 중 TGF-ss1이운반체로서 사용된 calcium carbonate (Biocoral)이라는 재료에 미치는 영향에대하여 조사하기 위해 새로운 조직계측학적 기준들을 첨가하여 실험을 재실시 하였다.새롭게 생성된 골의 양 (area)과 수직적인 높이 (height)는 두 실험 군간에 유의성 있는 차이가 없었고, 새로 생성된 백악질은 극히 제한적이었다. 잔존하는 운반체 (calcium carbonate)의 양을 비교해보았을 때, rhTFG-ss1군에서 운반체의 양이 현저히 감소됨을 관찰할 수 있었다. 결론적으로rhTFG-ss1이 calcium carbonate 운반체를 일련의 생물학적인 반응을 통하여흡수시킬 수 있다는 사실이 입증되었고, 이를 더 넓은 의미로 해석한다면치주조직재생에 사용되는 여러 성장인자들이 운반체로 사용되는 생물학적물질들에 영향을 미칠 수 있다는 결론을 내릴 수 있겠다. [영문]Background: In a previous study, recombinant human TGF-ss1 (rhTGF-ss1) in a calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for guided tissue regeneration (GTR) to study whether rhTGF-ss1 would enhance or accelerate periodontal regeneration. The results showed minimal benefits of rhTGF-ss1 and a clear account for this could not be offered. One potential cause may be that the rhTGF-ss1 formulation was biologically inactive. Several growth or differentiation factors have been suggested to accelerate degradation of biomaterials used as carriers. The objective of this study was to evaluate possible activity of rhTGF-ss1 on biodegradation of the calcium carbonate carrier.Methods: rhTGF-ss1 in a putty-formulated particulate calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for GTR in five Beagle dogs. Contralateral defects received the calcium carbonate carrier combined with GTR without rhTGF-ss1 (control). The animals were euthanized at week 4 week postsurgery when block-biopsies of the defect sites were collected for histologic and histometric analysis. Radiographs were obtained at defect creation, week 2 and week 4.Results: No statistically significant differences were observed in new bone formation (bone height and area) among the treatments. However, total residual carrier was significantly reduced in sites receiving rhTGF-ss1 compared to control (p=0.04). Similarly, carrier density was considerably reduced in sites receiving rhTGF-ss1 compared to control, the difference being borderline statistically significant (p=0.06).Conclusions: Within the limitations of the study, it may be concluded that rhTGF-ss1 accelerates biodegradation of a particulate calcium carbonate biomaterial indicating a biologic activity of the rhTGF-ss1 formulation apparently not encompassing enhanced or accelerated periodontal regeneration.ope

차폐막 노출이 발치 후 치조제 보존술의 결과에 미치는 영향에 관한 임상적 연구

Purpose: Following tooth extraction caused by severe periodontitis, alveolar ridge dimension lose their original volume. To reduce the alveolar ridge dimension, the ridge preservation technique has been introduced and tested in many clinical studies with membrane alone or membrane plus graft, achieving reduced ridge loss compared to extraction only. The aim of the present clinical study was to compare the post-extraction dimensional changes in the membrane exposure group to non-exposure group during healing period following ridge preservation technique. Methods: Ridge preservation was performed in 44 extraction sites. After extraction, deproteinized bovine bone mineral coated with synthetic oligopeptide (Ossgen-) or deproteinized bovine bone mineral (Bio-) was implanted into the socket. A collagen membrane (Bio-) was trimmed to cover the socket completely and applied to the entrance of the socket. Four clinical parameters were compared between baseline and 6 months. Results: During healing period, membrane exposure was observed at 19 sites. At the re-entry, hard newly formed tissue were observed at the ridge preservation site. The grafted socket sites were well preserved in their volume dimension. In both groups, horizontal ridge width was reduced and vertical height was increased. There were not statistically significant differences in horizontal (-1.32 mm vs -1.00 mm) and vertical ridge change (2.24 mm vs 2.37 mm at buccal crest, 1.36 mm vs. 1.53 mm at lingual crest) between two groups. Conclusions: The ridge preservation approach after tooth extraction effectively prevented resorption of hard tissue ridge in spite of membrane exposure during healing period.이 연구는 (주)나이벡의 지원으로 수행되었습니다

피브린 결합능을 가진 합성 펩타이드의 치주인대 세포에 대한 생물학적 영향

Purpose: Fibronectin(FN), one of the major components of ECM, mediates wide variety of cellular interactions including cell adhesion, migration, proliferation and differentiation. In this study, we used synthetic peptides based on fibrin binding sites of amino-terminal of FN and evaluated their biologic effects on periodontal ligament(PDL) cells. Materials and methods: PDL cells were cultured on synthetic oligopeptides coated dishes and examined for cell adhesion, proliferation via confocal microscope. For detection of ERK1/2, cells were plated and Western blot analysis was performed. Results: PDL cells on synthetic oligopeptide coated dishes showed enhanced cell adhesion and proliferation. Western blot analysis revealed increased level of ERK1/2 phosphorylation in cells plated on FN fragment containing fibrin-binding domain(FF1 and FF5) coated dishes. Conclusion: These results reveals that FN fragment containing fibrin-binding domain possess an enhanced biologic effect of PDL ligament cells

The cumulative survival rate of dental implants with micro-threads: a long-term retrospective study

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 external and 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.N

사람 치은 섬유아세포에서의 Tannerella forsythia 전세균, 막단백질, 당지질에 의한 염증성 사이토카인 발현

Purpose: The purpose of this study was to investigate induction of cytokine expression in human gingival fibroblasts (HGFs) by whole cell and the components of T. forsythia. Material and Methods: After HGFs were treated with lipopolysaccharide (LPS), membrane protein isolated from T. forsythia or culture media of T. forsythia, the induction of interleukin (IL)-1, IL-6 and IL-8 was examined with real-time PCR and ELISA. Their induction ability of cytokines was compared with whole bacteria. Result: The expression of IL-6 and IL-8 was significantly induced in HGFs by whole bacteria and membrane protein. The expression of IL- was induced by membrane protein of T. forsythia, not by whole bacteria. LPS and condition media of T. forsythia slightly activated HGFs. Conclusion: The membrane protein of T. forsythia could be one of virulence factors

민감성 치아에 대한 수산화인회석 함유 치약의 임상적 효과

Purpose: The aim of this study was to compare the effectiveness of hydroxyapatite containing toothpaste with positive control toothpastes in reducing dentine hypersensitivity. Materials and methods: This clinical trial was a double-blind, randomized, parallel group comparison of two, namely hydroxyapatite containing toothpaste and strontium chloride containing toothpaste. A total of 55 subjects were included in this study. The subjects were given randomly assigned one of the two toothpastes after received tooth brushing instruction at baseline. Some clinical indices(PI, GI, PD), verbal rating score(VRS) for sensitivity to stimulus, the effect in relieving sensitivity and visual analogue scale(VAS) for sensitivity at baseline, week 2, week 4 and week 8 were assessed. All data were evaluated by intention-to-treat analysis. Results: Overall, PI and GI scores were significantly reduced compare baseline in all groups(p0.05). Conclusion: This study demonstrated that the new hydroxyapatite containing toothpaste was similarly effective in reducing dentine hypersensitivity with pre-existing benchmark toothpaste.본 역구는 (주)디오의 연구비 지원으로 수행되었습니다

Survey study of powered toothbrush with guiding device for oral hygiene improvement

Purpose: This study was performed to evaluate the effect of powered toothbrush with a wireless remote display on the subjective and objective oral hygiene improvement. Methods: One hundred and fifteen subjects in healthy or mild gingivitis status between the ages of 20 and 90 were recruited and reviewed for study inclusion criteria. At first visit, 115 pre-screened subjects filled in the questionnaire form which consisted of demographic factors, behavioral factors (smoking, alcohol consumption), toothbrushing habits (brushing time and frequency), self-reported oral health status, and self-satisfaction. Baseline clinical indices (Plaque index, Gingival index) were also recorded by a periodontist. Subjects were instructed how to use powered toothbrush with a wireless remote display, and were provided with it. Thirty days after first visit, 90 subjects returned for the second assessment by self-reported questionnaire form and professional clinical checkup. Statistical analysis was performed using paired t-test for the difference between baseline and second visit data. The relationship among variables was examined with chi-square test and Fisher' s exact test. Results: Significant differences were not found on self-reported satisfaction related with sex, smoking, alcohol consumption (P<0.05). Self-reported tooth brushing habit was improved in the aspect of brushing time and frequency. Significant differences were found on the self-reported oral health status, self-satisfaction, and clinical indices between the baseline and second visit data (P<0.01). Clinical indices were significantly reduced after using powered toothbrush with a wireless remote display (P<0.01). No adverse reactions were reported during the study period. Conclusions: Powered toothbrush with a wireless remote display successfully promoted oral hygiene from the subjective and objective viewpoint after 30 days of home usage

Investigation of postnatal stem cells from canine dental tissue and bone marrow

Purpose: The aim of this study was to evaluate the stemness of cells from canine dental tissues and bone marrow. Methods: Canine periodontal ligament stem cells (PDLSC), alveolar bone stem cells (ABSC) and bone marrow stem cells(BMSC) were isolated and cultured. Cell differentiations (osteogenic, adipogenic and chondrogenic) and surface antigens (CD146, STRO-1, CD44, CD90, CD45, CD34) were evaluated in vitro. The cells were transplanted into the subcutaneous space of nude mice to assess capacity for ectopic bone formation at 8 weeks after implantation. Results: PDLSC, ABSC and BMSC differentiated into osteoblasts, adipocytes and chondrocytes under defined condition. The cells expressed the mesenchymal stem cell markers differently. When transplanted into athymic nude mice, these three kinds of cells with hydroxyapatite /- tricalcium phosphate (HA/TCP) carrier showed ectopic bone formation. Conclusions: This study demonstrated that canine dental stem cells have stemness like bone marrow stem cells. Transplantation of these cells might be used as a therapeutic approach for dental stem cell-mediated periodontal tissue regeneration.이 논문은 2008년도 과학기술부의 재원으로 한국과학재단의 지원을 받아 수행된 연구임(No. M10646010003-08N4601-00310)