• International Journal of Oral Biology
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• 제32권1호
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• pp.13-22
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• 2007

The stem cell research is emerging as a cutting edge topic for a new treatment for many chronic diseases. Recently, dental stem cell would be possible for regeneration of tooth itself as well as periodontal tissue. However, the study of the cell characterization is scarce. Therefore, we performed the genetic profiling and the characterization of mouse fetus/neonate derived dental tissue and cell to find the identification during dental development. We separated dental arch from mandibles of 14.5 d fetal mice and neonate 0 d under the stereoscope, and isolated dental cells primarily from the tissues. Then, we examined morphology and the gene expression profiles of the primary cells and dental tissues from fetus/neonate and adult with RT-PCR. Primary dental cells showed heterogeneous but the majority was shown as fibroblast-like morphology. The change of population doubling time levels (PDLs) showed that the primary dental cells have growth potential and could be expanded under our culture conditions without reduction of growth rate. Immunocytochemical and flow cytometric analyses were performed to characterize the primary dental cell populations from both of fetus (E14.5) and neonate. Alpha smooth muscle actin (${\alpha}-SMA$), vimentin, and von Willebrand factor showed strong expression, but desmin positive cells were not detected in the primary dental cells. Most of the markers were not uniformly expressed, but found in subsets of cells, indicating that the primary dental cell population is heterogeneous, and characteristics of the populations were changed during culture period. And mesenchymal stem cell markers were highly expressed. Gene expression profile showed Wnt family and its related signaling molecules, growth factors, transcription factors and tooth specific molecules were expressed both fetal and neonatal tissue. The tooth specific genes (enamelin, amelogenin, and DSPP) only expressed in neonate and adult stage. These expression patterns appeared same as primary fetal and neonatal cells. In this study we isolated primary cells from whole mandible of fetal and neonatal mice. And we investigated the characteristics of the primary cells and the profile of gene expressions, which are involved in epithelial-mesenchymal interactions during tooth development. Taken together, the primary dental cells in early passages or fetal and neonatal mandibles could be useful stem cell resources.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.637-646
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• 2007

Implants placed immediately after tooth extraction have been shown to be a successfully predictable treatment modality. Several clinical papers suggest that placing implants immediately after tooth extraction may provide some advantages: reduction of the number of surgical procedures or patient visits, preservation of the dimensions of alveolar ridge, and shortening of the interval between the removal of the tooth and the insertion of the implant supported restoration. In this case report, three patients received single immediate implant placements to replace a maxillary anterior tooth at the time of extraction. As the three cases were somewhat different, treatment protocols had to be modified as follows: Case 1. Immediate implant placement with healing abutment connection. Case 2. Immediate implant placement with immediate provisionalization. Case 3. Immediate implant placement with Guided Bone Regeneration(GBR). Every implant of these cases was placed in proper position buccolingually, mesiodistally and apicocoronally, The procedures following implantation such as immediate provisionalization and GBR were free of problem. Healing of each case was uneventful. In all cases, treatment outcomes were mostly satisfactory and the results maintained during follow-up periods. However, one case (Case 3) showed some papilla loss due to failure in delicate soft tissue handling during surgery. This papilla loss was compromised by prosthetic means. In conclusion, immediate implant placement in the fresh extraction socket can be a valid and successful option of treatment in aesthetic area. Moreover, this treatment protocol seems to maintain the preexisting architecture of soft and hard tissues in most cases.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.723-737
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• 1997

본 연구의 목적은 조직유도재생술의 초기치유시에 구강양치액으로 사용되어지는 0.1% 클로르헥시딘과 0.2% 클로르헥시딘을 사용했을 경우, 양치액을 사용하지 않았을 경우의 세균감염 정도를 비교하는 것이다. 30명의 성인형 치주염에 이환되어진 사람을 대상으로 하였다. 초기치료(Scaling/Root planing/Oral hygiene instruction)를 시행한 후에 한 사람에 한 군데씩 선정하여 2급이나 3급의 치근이개부를 가지고 임상적으로 혹은 방사선학적으로 치간골내낭을 보이지 않는 치아에 통법에 따라 Gore-TexTM를 위치시켰다. 술후 5일간 항생제 (UnasynTM 375mg tablet p.o.tid)를 투여하고 차폐막을 제거할 때까지(4주 혹은 6주) 10명의 환자에게는 0.1% 클로르헥시딘을, 다른 10명의 환자에게는 0.2% 클로르헥시딘으로 구강양치를 하게 하고, 또 다른 10명의 환자에게는 구강양치액을 사용하지 않도록 하였다. 또 1주일에 한번씩 전문가구강위생술식을 실시하였다. 4주나 6주 후에 차폐막을 제거하고 주사전자현미경, 혐기성 세균배양을 이용하여 세균감염정도를 비교하였다. 1. 주사전자현미경으로 관찰시에 0.1% 클로르헥시딘을 사용했을 경우와 0.2% 클로르헥시딘을 사용했을 경우, 클로르헥시딘을 사용하지 않은 경우에 별 차이를 발견할 수 없었다. 2. 혐기성 세균배양시에 0.2% 클로르헥시딘을 사용했을 경우, 0.1%클로르헥시딘을 사용했을 경우보다 적은 수의 세균 수를 보였으나 통계적으로 유의할 만한 차이는 보이지 않았다. 클로르헥시딘을 사용하지 않은 경우에는 다른 두 경우에 비해 통계적으로 유의할 만한 차이를 보였다.(P<0.05) 3. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia를 인지한 경우에는 세 경우 모두 비슷한 비율로 발견되었다.

• Journal of Periodontal and Implant Science
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• 제46권6호
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• pp.415-425
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• 2016

Purpose: The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach. Methods: This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation. Results: All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by $1.56{\pm}0.90mm$ in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by $0.25{\pm}0.66mm$. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure (P<0.05). Radiographic analysis showed that the hidden X suture had a significant effect in preserving horizontal width and minimizing vertical reduction in comparison to X suture (P<0.05). Conclusions: Our study provided clinical and radiographic verification of the efficacy of the hidden X suture in preserving the width of KT and the dimensions of the alveolar ridge after ARP.

• Journal of Periodontal and Implant Science
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• 제47권3호
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• pp.165-173
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• 2017

Purpose: The aim of this study was to radiographically and clinically compare the effect of extracellular matrix (ECM) membranes on dimensional alterations following a ridge preservation procedure. Methods: One of 2 different ECM membranes was applied during a ridge preservation procedure. A widely used ECM membrane (WEM; Bio-Gide, Geistlich Biomaterials, Wolhusen, Switzerland) was applied in the treatment group and a newly developed ECM membrane (NEM; Lyso-Gide, Oscotec Inc., Seongnam, Korea) was applied in the control group. Cone-beam computed tomography (CBCT) scans and alginate impressions were obtained 1 week and 6 months after the ridge preservation procedure. Results were analyzed using the independent t-test and the nonparametric Mann-Whitney U test. Results: There were no significant differences between the ECM membranes in the changes in the dimension, width, and height of the extraction socket or the quantity of bone tissue. Conclusions: The NEM showed comparable clinical and radiographic results to the WEM following the ridge preservation procedure.

• 대한소아치과학회지
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• 제36권4호
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• pp.640-646
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• 2009

치아에 외상을 받은 경우 치수 생활력의 상실은 흔한 일이다. 치수 생활력을 검사하는 방법으로는 임상적, 방사선학적으로 여러 가지가 있지만, 미성숙 외상치의 경우 일시적 현상과 가성 반응이 나타날 수 있으므로 치수 괴사에 대한 정확한 진단은 매우 어렵다. 생활력을 상실한 치아는 염증성 치근흡수, 치근단 낭종 등의 발생을 방지하기 위하여 치수 치료를 시행한다. 그러나 미성숙 영구치의 경우, 치수 치료를 시행 후 치근 성장이 정지될 수 있어 결과적으로 얇고 짧은 치근이 형성되어 장기적인 예후는 좋지 않다. 본 임상 증례에서는 외상으로 인하여 실활된 초기 영구치에서 치근단부의 최소한의 침습적 치근단 형성술로 계속된 치근 형성을 보여 이에 보고하는 바이다.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.689-711
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• 2001

The purpose of this study was to compare clinical results of guided tissue regeneration(GTR) using either a nonresorbable ePTFE membrane or a resorbable membrane made from a synthetic copolymer of glycolide and lactide(PLGA) in the treatment of human class Ⅱ furcation defects. The ePTEE membranes were applied to 16 patients with maxillary molar buccal class Ⅱ furcation defects as Group I, PLGA membranes were applied to 15 patients with maxillary molar buccal class Ⅱ furcation defects as Group Ⅱ, ePTFE membranes were applied to 20 patients with mandibular molar buccal class Ⅱ furcation defects as Group Ⅲ and PLGA membranes were applied to 20 patients with mandibular molar buccal class Ⅱ furcation defects as Group Ⅳ and bone graft materials(DFDBA) were applied in all groups. Probing depth, gingival recession, clinical attachment level, tooth mobility and sulcus bleeding index(SBI) were measured at baseline, 3, 6 and 12months postoperatively. In addition, membrane exposure levels were measured at surgery, 1, 2 and 6weeks postoperatively and postoperative complications were evaluated. The results were as follows: In all groups, there were statistically significant differences in probing depth reduction, gain of clinical attachment and mobility reduction at values of 3, 6 and 12months postoperatively compared to values of baseline, whereas no significant differences in SBI except Group I and gingival recession(p<0.05). Membrane exposure levels were increased at 1, 2 and 6weeks postopratively compared to value of baseline in Group I(p<0.05). There were no statistically significant differences between ePTFE and PLGA membrane in probing depth, clinical attachment level and SBI. There were minimal gingival recession and membrane exposure in Group Ⅳ and pain and swelling were the most common postoperative complications in Group Ⅱ, Ⅲ(p<0.05). In conclusion, this study showed that both nonresorbable membrane and resorbable membrane were effective similarly in the treatment of class Ⅱ furcation defects, without statistical differences in clinical measurements.

• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.149-156
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• 2009

Purpose: Deproteinized bovine bone substitutes are commonly used in dental regenerative surgery for treatment of alveolar defects. In this study, three different bovine bone minerals - OCS-B (NIBEC, Seoul, Korea), Bio-Oss (Geistlich - Pharma, Switzerland), Osteograft/N - 300 (OGN, Dentsply Friadent Ceramed. TN, USA) - were investigated to analyze the basic characteristics of commercially available bone substitutes. Methods: Their physicochemical properties were evaluated by scanning electron microscopy, energy dispersive X-ray spectrometer (EDS), surface area analysis, and Kjeldahl protein analysis. Cell proliferation and alkaline phosphatase (ALP) activity of human osteosarcoma cells on different bovine bone minerals were evaluated. Results: Three kinds of bone substitutes displayed different surface properties. Ca/P ratio of OCS - B shown to be lower than other two bovine bone minerals in EDS analysis. Bio-Oss had wider surface area and lower amount of residual protein than OCS - B and OGN. In addition Bio - Oss was proved to have lower cell proliferation and ALP activity due to lots of residual micro particles, compared with OCS - B and OGN. Conclusions: Based on the results of this study, three bovine bone minerals that produced by similar methods appear to have different property and characteristics. It is suggested that detailed studies and quality management is needed in operations for dental use and its biological effects on new bone formation.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.877-889
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• 2005

This study was designed to compare the effects of treatment using chitosan membrane $(Nanogide-C^{(R)})$ resorbable barrier with control treated by polylactic acid/polylacticglycolic acid membrane(PLA/PLGA membrane, $Biomesh^{(R)}$). 44 furcation defecs from 44 patients with class 2 furcation degree were used for this study, 22 sites of them were treated by chitosan membrane as experimental group and 22 site were treated by PLA/PLGA membrane as control group. Clinical parameters including probing depth, gingival recession, attachment level and radiographic examination were evlauated at base line, 1 month, 2 month and 3 month. after surgery. Statistical test used to analyze these data included paired t-test, one way ANOVA. The results are as follows : 1. Probing depth was significanlly decreased in the two group and there were significant differences between groups(p<0.05). 2. Gingival recession was not significanlly increased in the two group and there were no significant differences between groups(p<0.05). 3. Loss of attachment was statistically decreased in the two group and there were no significant differences between groups(p<0.05). 4. Horizontal bone level was significanlly increased in the two group and there were significant differences between groups(p<0.05). On the basis of these results, chitoans resorbable membrane has similar potential to PLA/PLGA membrane in GTR for furcation defect.

• Journal of Periodontal and Implant Science
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• 제49권4호
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• pp.258-267
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• 2019

Purpose: Increased bone regeneration has been achieved through the use of stem cells in combination with graft material. However, the survival of transplanted stem cells remains a major concern. The purpose of this study was to evaluate the viability of transplanted mesenchymal stem cells (MSCs) at an early time point (24 hours) based on the type and form of the scaffold used, including type I collagen membrane and synthetic bone. Methods: The stem cells were obtained from the periosteum of the otherwise healthy dental patients. Four symmetrical circular defects measuring 6 mm in diameter were made in New Zealand white rabbits using a trephine drill. The defects were grafted with 1) synthetic bone (${\beta}$-tricalcium phosphate/hydroxyapatite [${\beta}-TCP/HA$]) and $1{\times}10^5MSCs$, 2) collagen membrane and $1{\times}10^5MSCs$, 3) ${\beta}-TCP/HA+collagen$ membrane and $1{\times}10^5MSCs$, or 4) ${\beta}-TCP/HA$, a chipped collagen membrane and $1{\times}10^5MSCs$. Cellular viability and the cell migration rate were analyzed. Results: Cells were easily separated from the collagen membrane, but not from synthetic bone. The number of stem cells attached to synthetic bone in groups 1, 3, and 4 seemed to be similar. Cellular viability in group 2 was significantly higher than in the other groups (P<0.05). The cell migration rate was highest in group 2, but this difference was not statistically significant (P>0.05). Conclusions: This study showed that stem cells can be applied when a membrane is used as a scaffold under no or minimal pressure. When space maintenance is needed, stem cells can be loaded onto synthetic bone with a chipped membrane to enhance the survival rate.