Research progress of periodontal tissue regeneration by combined biomaterials of dental derived mesenchymal stem cells / 口腔医学

@#The ultimate treatment goal of periodontitis is the structural and functional regeneration of periodontium. However, existing methods for periodontal regeneration have difficulties in regenerating the hierarchical structure. Therefore, stem cell-based tissue engineering has attracted more and more attention for its advantages of self-renewal and multi-lineage differentiation potential. This review summarized the progress of research on periodontal tissue regeneration by combined biomaterials of dental-derived stem cells. It is pointed out that the application of autologous stem cell transplantation is limited by the donor source, and the subsequent research should focus on the development of multi-phase scaffold materials and the attempt to establish a stem cell bank.

Applicatoin of chitosan-based hydrogel in oral tissue engineering / 中南大学学报(医学版)

Pulpitis, periodontitis, jaw bone defect, and temporomandibular joint damage are common oral and maxillofacial diseases in clinic, but traditional treatments are unable to restore the structure and function of the injured tissues. Due to their good biocompatibility, biodegradability, antioxidant effect, anti-inflammatory activity, and broad-spectrum antimicrobial property, chitosan-based hydrogels have shown broad applicable prospects in the field of oral tissue engineering. Quaternization, carboxymethylation, and sulfonation are common chemical modification strategies to improve the physicochemical properties and biological functions of chitosan-based hydrogels, while the construction of hydrogel composite systems via carrying porous microspheres or nanoparticles can achieve local sequential delivery of diverse drugs or bioactive factors, laying a solid foundation for the well-organized regeneration of defective tissues. Chemical cross-linking is commonly employed to fabricate irreversible permanent chitosan gels, and physical cross-linking enables the formation of reversible gel networks. Representing suitable scaffold biomaterials, several chitosan-based hydrogels transplanted with stem cells, growth factors or exosomes have been used in an attempt to regenerate oral soft and hard tissues. Currently, remarkable advances have been made in promoting the regeneration of pulp-dentin complex, cementum-periodontium-alveolar bone complex, jaw bone, and cartilage. However, the clinical translation of chitosan-based hydrogels still encounters multiple challenges. In future, more in vivo clinical exploration under the conditions of oral complex microenvironments should be performed, and the combined application of chitosan-based hydrogels and a variety of bioactive factors, biomaterials, and state-of-the-art biotechnologies can be pursued in order to realize multifaceted complete regeneration of oral tissue.

Research progress on basic fibroblast growth factor in promoting periodontal tissue regeneration / 口腔疾病防治

@#Basic fibroblast growth factor (bFGF) exhibits superior biological functions by improving periodontal inflammation, promoting the migration and proliferation of periodontal-related stem cells, promoting the formation of blood vessels and periodontal ligament-like tissue, and regulating the formation of bone/cementum. It plays an important role in tooth development, repair and regeneration. bFGF can be combined with seed cells and scaffold materials for periodontal tissue regeneration, which has been verified in a number of experimental studies. However, the application of bFGF alone as a drug in clinical treatment requires further research.

Effect of miR-21 on the proliferation and osteogenic differentiation of human periodontal ligament stem cells / 口腔疾病防治

Objective @# To explore the effect of miR-21 on human periodontal ligament stem cells (PDLSCs) proliferation and osteogenesis and to provide a theoretical basis for the stem cell treatment of periodontitis.@*Methods@#hPDLSCs were isolated and cultured with the enzymatic tissue block method, and surface molecules (CD34, CD45, CD90 and CD105) were detected by flow cytometry. An miR-21 mimics (pre-miR-21) and inhibitor (anti-miR-21) were transfected into hPDLSCs by Lipofectamine 2000. The experiment groups: mimics-NC group, mimics group, inhibitor group, and inhibitor-NC group. The transfection efficiency of miR-21 was determined by qRT-PCR. Proliferation was detected by CCK-8 and flow cytometry. The osteogenic differentiation ability of hPDLSCs was determined by alizarin red staining. Western blot was used to detect the protein expression of osteogenic related genes: Runx2.@*Results@#The mRNA expression of miR-21in the mimics group was significantly higher than that in the mimics-NC group; additionally, the expression in the inhibitor group was significantly weaker than that in the inhibitor-NC group (P < 0.05). hPDLSCs proliferation and the S phase cell ratio in the mimics group were stronger than those in the mimics-NC group(P < 0.05); those in the inhibitor group were weaker than those in the inhibitor-NC group (P < 0.05). After alizarin red staining, the mimics group was found to have more mineralized modules than mimics-NC group, and the inhibitor group had fewer than that in the inhibitor-NC group. Runx2 protein expression in the mimics group was higher than that in the mimics-NC group (P <0.05), and expression was lower in the inhibitor group than in the inhibitor-NC group (P < 0.05).@*Conclusion@#miR-21can promote the proliferation and osteogenesic differentiation of hPDLSCs.

Research progress on cell sheet technology and its application in periodontal tissue regeneration / 口腔疾病防治

@#At present, conventional periodontal treatment cannot achieve complete and effective periodontal tissue regeneration. Cell sheet technology (CST) is a kind of cell transplantation method without scaffold material that can maintain complete extracellular matrix, important ion channels of cells, growth factor receptors, etc., and ensure the interaction between cells and the extracellular matrix. In this paper, the application and research progress of the cell sheet in the field of periodontal tissue regeneration are reviewed. Different types of seed cells can be prepared into monolayer cell sheet, multilayer cell sheet, cell sheet fragments and cell sheet polymers. Among them, the monalayer cell sheet is easily damaged and requires high deoperator; the multilayer cell sheet shows improved mechanical properties, but its thickness needs to be controlled to avoid cell necrosis. The cell sheet fragment can be used in the narrow space between the alveolar bone and root cementum to reduce the difficulty of operation and improve the mechanical properties of the cell sheet. Cell sheet polymers are three-dimensional structures that can provide strong mechanical support and improve the stability of the cell sheet, but the stability of their biological activity needs to be further improved. In methods for construction of the cell sheet, the antifibrosis and antiangiogenesis properties of the amniotic sheet have shown that this structure is suitable as the matrix of cell culture; the method of using a temperature-sensitive culture dish is simple and easy; continuous induction with vitamin C can retain some important proteins on the cell surface; and the magnetic tissue engineering method can increase cell adhesion and easily form a stable cell sheet. The above methods have their own characteristics. In clinical applications, monolayer cell sheet is mainly used for direct transplantation to the receiving site to construct periodontal tissue; multilayer cell sheet of the same or different species overlap and are then transplanted to the receiving site; and multilayer cell sheet of the same kind are wrapped with scaffold material and then transplanted to the receiving site to construct a three-dimensional structure. Overall, cell sheet technology has shown good potential in periodontal tissue regeneration.

Application of 3D printing technology in preparation of scaffolds for periodontal tissue regeneration / 口腔疾病防治

@#How to obtain ideal regeneration of periodontal tissue remains a challenge in the clinical treatment of periodontitis. Three-dimensional printing technology is based on computer-aided design, which produces materials with specific 3D shapes by layer-by-layer superposition, and has been applied to periodontal tissue regeneration therapy, this method offers hope to achieve ideal periodontal regeneration. This article reviews the application of 3D printing technology in the field of periodontal tissue regeneration. The literature review results show that 3D printing technology can design three-dimensional structures using computer software in advance and produce materials with specific three-dimensional structures. 3D printing technology mainly includes selective laser sintering, selective laser melting, extrusion forming printing and 3D bioprinting. At present, the support materials prepared by 3D printing technology include ceramic materials, polymer materials and metals. Submaterials have been extensively studied given their high adjustability, and 3D-printed personalized titanium mesh has been applied in the clinic. Multiphase materials prepared by 3D-printing technology can regenerate periodontal tissue in animal experiments, but the effect is not good in patients with periodontitis. In addition, 3D printing of composite scaffolds for periodontal tissue regeneration need to be further studied.

Effect of recombinant human amelogenin-loaded PCLA-PEG-PCLA hydrogels on biological properties of human periodontal ligament fibroblasts / 上海交通大学学报（医学版）

Objective • To determine the effect of recombinant human amelogenin (rhAm)-loaded PCLA-PEG-PCLA hydrogels on cell proliferation, immigration, attachment and osteogenic differentiation of human periodontal ligament fibroblasts (HPDLFs). Methods • HPDLFs were obtained by tissue block method in vitro from extracted premolars and the 3rd-5th passages of HPDLFs were treated with DMEM medium (control group), 20 μg/mL rhAm (rhAm group) or rhAm-loaded PCLA-PEG-PCLA hydrogels (rhAm-loaded hydrogel group). Proliferation activity was measured by CCK-8, while cell migration was assayed both by wound-healing experiment in vitro and Transwell experiment. Cell attachment was measured by hemocytometer and observed by scanning electron microscope. Osteogenic differentiation was measured by real-time PCR, with ALP, Runx2, CEMP1 and CAP as the target genes. Results • RhAm-loaded PCLA-PEG-PCLA hydrogels had no significant effect on cell growth curve of HPDLFs, but promoted cell proliferation after 3 days (P<0.05). RhAm accelerated cell migration mostly both in wound-healing experiment and Transwell experiment, with rhAm-loaded hydrogels in the second place. RhAm-loaded hydrogels promoted cell attachment, and in the 4th hour the promotion was of statistic significance (P<0.05). Meanwhile cells of rhAm group and rhAm-loaded hydrogel group had a better stretch condition than control group under the scanning electron microscope. After culture with rhAm-loaded hydrogels, ALP, Runx2, CEMP1, and CAP mRNA were upregulated in different time points. Conclusion • Recombinant human amelogenin-loaded PCLA-PEG-PCLA hydrogels can significantly improve proliferation, attachment and osteogenic differentiation of HPDLFs, but has no effect on cell migration on a statistical scale.

Endodontic-periodontal combined therapy for type Ⅲ dens invaginatus in maxillary lateral incisor: a case report / 华西口腔医学杂志

We report a clinical case of type Ⅲ dens invaginatus with endodontic-periodontal lesion in a maxillary lateral incisor. The palatal radicular anomaly predisposed the tooth to periodontal lesions. The caries along the palatal groove caused tooth pulp necrosis and periapical lesions. By means of microscopic root canal therapy, apical surgery, and guided periodontal tissue regeneration, the apical and periodontal infection were controlled, and the affected tooth was retained.

Effects of bacterial lipopolysaccharide on the mineralization and differentiation of periodontal ligament stem cells / 医学研究生学报

Objective Periodontal tissue engineering has shown a highlight prospect in the treatment of periodontitis,but the related clinical experiments have not achieved the predetermined goal. In this study,we analyzed the reasons for the limited clinical efficacy of periodontal tissue engineering. Methods We primarily cultured the periodontal tissue from the young permanent teeth extracted for or-thodontic treatment,isolated periodontal ligament stem cells (PDLSCs),and transplanted the well-grown third-generation PDLSCs onto the fluorapatite-polycaprolactone (FA-PCL) nanofiber scaffolds and PCL nanofiber scaffolds. We randomly divided the cells into groups A (cultured with 10 ng/mL porphyromonas gingivalis lipopo-lysaccharide (Pg-LPS)+FA-PCL),B (cultured with 10 ng/mL PG-LPS+PCL),C (cultured with 10 μg/mL PG-LPS+FA-PCL),D (cultured with 10 μg/mL PG-LPS+PCL),E (cultured with FA-PCL),and F (cultured with PCL),and observed their proliferation,differentiation and mineralization. Results The PDLSCs adhered and grew well after transplanted onto the nanofiber scaffolds and their proliferation significantly increased in groups A and B but decreased in C and D as compared with E and F. At 7 days,the expres-sions of ALP and mineralization-related genes runx2 and SPP1 in the PDLSCs were significantly higher in group E than in the other five groups (P<0.05),but higher groups A and C than in B and D as well as in A than in C. At 28 days,alizarin red and Von Kossa stai-ning showed a higher positivity in group E than in the other five groups,but higher groups A and C than in B and D as well as in A than in C. Conclusion The inflammatory environment not only affects the proliferation of PDLSCs,but also inhibits their differentiation and mineralization. The FA-PCL scaffold can reduce the cytotoxic effect of PG-LPS.

Histologic evaluation of various membranes on periodontal tissue regeneration of 1-wall intrabony defects in dogs / 대한치주과학회지

PURPOSE: In dental clinical fields, various periodontal membranes are currently used for periodontal regeneration. The periodontal membranes are categorized into two basic types: resorbable and non-resorbable. According to the case, clinician select which membrane is used. Comparing different membranes that are generally used in clinic is meaningful. For this purpose, this study evaluates histological effects of various membranes in canine one wall intrabony defect models and it suggest a valuation basis about study model. MATERIAL AND METHOD: The membranes were non-resorbable TefGen Plus(R), resorbable Gore Resolut XT(R) and resorbable Osteoguide(R). One wall intrabony defects were surgically created at the second and the mesial aspect of the fourth mandibular premolars in either right or left jaw quadrants in two dogs. The animals were euthanized 8 weeks post-surgery when block sections of the defect sites were collected and prepared for histological evaluation. RESULTS: 1. While infiltration of inflammatory cells were observed in control, TefGen Plus(R) and Gore Resolut XT(R), it was not observed in Osteoguide(R). 2. TefGen Plus(R) had higher integrity than others and Osteoguide(R) was absorbed with folding shape. Gore Resolut XT(R) was divided everal parts during resorbtion and it was also absorbed from inside. 3. Quantity of new bone and new cementum was not abundant in all membranes. 4. For histologic evaluation of membranes we should consider infiltration of inflammatory, migration of junctional epithelium, integrity of membrane, quantity of new bone and new cementum, connective tissue formation and aspect of resorption. CONCLUSION: This histologic evaluation suggests that Osteoguide(R) provides periodontal regenerative environment with less inflammatory state. It is meangful that this study model suggests a valuation basis about other study model.

The clinical effects of Calcium Sulfate combined with Calcium Carbonate in treating intrabony defects / 대한치주과학회지

PURPOSE: If bone grafts and guided tissue regeneration are effective individually in treating osseous defects, then the question is, what would happen when they are combined. Bone grafts using Calcium Carbonate(Biocoral) and Guided Tissue Regeneration using Calcium Sulfate(CALMATRIX) will maximize their advantages and show the best clinical results in intrabony defects. This study was to compare the effects of a combination of CS and CC with control treated only with modified widman flap in a periodontal repair of intrabony defects. MATERIALS AND METHODS: 30 patients with chronic periodontitis were used in this study. 10 patients were treated with a combination of CS and CC as the experimental groupII and another 10 patients were treated with CC as the experimental groupI, and the remaining 10 patients, the control group were treated only with modified widman flap. Clinical parameters including probing depth, gingival recession, bone probing depth and loss of attachment were recorded 6 months later. RESULTS: The probing depth changes were 3.30+/-1.34 mm in the control group, 4.2+/-1.55 mm in the experimental groupI(CC) and 5.00+/-1.33 mm in the experimental groupII(CS+CC). They all showed a significant decrease 6 months after surgery(p <0.01). There was a significant difference(p <0.05) between the control and experimental group. However there were no significant difference(p <0.05) between the experimental groupIand II. The gingival recession changes w -1.30+/-1.25 mm in the control group, This is a significant difference(p <0.01). However, there was a -0.50+/-0.53 mm change in the experimental groupI(CC) and -0.60+/-0.97 mm in the experimental groupII(CS+CC). In addition, in terms of gingival recession, there was a no significance difference(p <0.05) among the groups. The clinical attachment level changes were 2.00+/-1.33 mm in the control group, 3.60+/-1.58 mm in the experimental groupI(CC) and 4.40+/-1.17 mm in the experimental groupII(CS+CC). They all showed a significant decrease 6 months after surgery(p <0.01). There was a significant difference(p <0.05) between the control and experimental group. However there was a no significance difference(p <0.05) between the experimental groupI andII. The bone probing depth changes were 0.60+/-0.52 mm in the control group, 3.20+/-1.48 mm in the experimental groupI (CC) and 4.60+/-1.43 mm in the experimental groupII(CS+CC). All of them showed a significant decrease 6 months after surgery(p <0.01), there was a significance difference(p <0.05) among the groups. CONCLUSION: Treatment using a combination of CS and CC have a potential to improve periodontal parameters in intrabony defects and More efficient clinical results can be expected in intrabony defects less than 2 walls grafted with CS and CC.

Effects of mixture of fibrin-fibronectin sealant system and calcuim carbonate in periodontal intrabony defects / 대한치주과학회지

Calcium carbonate(CC) is biocompatible and gradually absorb to be replaced by bone when implanted into bone tissue. Fibrin-fibronectin sealant system (FFSS) is a product of human-derived plasma. The effect is hemostasis, tissue fixation and adhesion, We expect synergic effects of this two materials in periodontal regeneration. When FFSS was grafted with bone graft in intrabony defects, could be eliminated exofolication of bone graft materials. This study evaluated above materials for periodontal regeneration of 6mm intrabony defects in 36 patients. Flap surgery was carried in 14 defects of control group. experimental group 1 was 11 defects grafted with calcium carbonate, experimental group 2 was 11 defects which were grafted with calcium carbonate with FFSS. The clinical parameters evaluated included changes in attachment level, probing depth, gingival recession at 6 months. Postsurgery probing depth reduction was 3.1 +/- 0.9mm in control, 3.8 +/- 1.6mm in experimental group 1, 4.1 +/- 1.1mm in experimental group 2. The result clinically and statistically improved compared to baseline(P<0.01), but the difference found among the groups were not statistically significant. Postsurgery clinical attachment level was 1.6 +/- 1.2mm in control, 3.5 +/- 2.0mm in experimental group 1, 3.3 +/- 1.2mm in experimental group 2. All of the control and experimental groups resulted in a statistically significant reduction from baseline(P<0.01). The reduction of the experimental groups were statistically significant from control(P<0.05). But the change between experimental group 1 and experimental group 2 was not statistically significant. We conclude that mixture of CC and FFSS is effective to periodontal regeneration in intrabony defect.

Effects of enamel matrix protein derivatives on the periodontal ligament like fibroblast and osteoblast like cells / 대한치주과학회지

Recent study on the enamel matrix derivatives explained on the effects of new bone and new attachment formation in infrabony pocket of periodontal defects. The purpose of this study was to investigate on the biological effects of enamel matrix derivatives to attachment, proliferation and activation of periodontal ligament and osteoblast cells. After treatment of osteoblast and PDL cells with various Emdogain concentration level(0.03microgram/ml, 3microgram/ml, 300 microgram/ml), activation of osteogenetic factor, calcified nodule formation and measuring alkaline phosphatase activity(ALP) were performed. 1. Both osteoblast and PDL cell showed increasing initial cell attachment with 300microgram/ml Emdogain concentration. 2. At the level of 300microgram/ml, accelerated proliferation of oseoblast and PDL cell was appeared. 3. As Emdogain's concentration increased, increased ALP activation of osteoblast was shown. In case of PDL cell, Emdogain increased ALP activation prominently at the level of 300microgram/ml. 4. No statistically significant activating change were founded at all of the concentrations of Emdogain on the activating of transcript factor Runx2 for differentiating osteoblast. 5. At the level of 300microgram/ml, calcified nodule formation was increased prominently to compare with other concentration. These results indicated that Emdogain should activate initial attachment, proliferation and activation, but not on Runx2 activation and can be used for useful tool of the treatment of periodontal tissue regeneration.

Clinical Long-term Assessment of Bioactive Glass Graft / 대한치주과학회지

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. To achieve periodontal regeneration, various kinds of methods have been investigated and developed, including guided tissue regeneration and bone graft. Bone graft can be catagorized into autografts, allografts, xenografts, bone substitutes. And materials of all types have different biological activity and the capacity for periodontal regeneration, but ideal graft material has not been developed that fits all the requirement of ideal bone graft material. Recently, bioactive glass that has been utilized in plastic surgery is being investigated for application in dental practice. But, there has not been any long-term assessment of bioactive glass when used in periodontal intrabony defects. The present study evaluates the long-term effects of bioactive glass on the periodontal regeneration in intrabony defects of human and the effect of plaqu control on long term treatment results after dividing patients into those who underwent 3-month regular check-up and those who didn't under go regular check-up The clinical effect on 74sites from 17 infrabony pockets of 11 patients were analyzed 36months after treatment. 51 sites which underwent regular check up were classified as the Follow-up group(F/U group), and 23 sites which did not undergo regular check up were classified as Non Follow-up group(Non F/U group). After comparing the probing depth, attachment loss, bone probing depth before and 36months after treatment, the following results could be concluded. 1. The changes of probing pocket depth showed a statistically significant decrease between after baseline and 36 months after treatment in F/U group(1.79+/-0.68mm) and did no show astatistically significant decrease between after baseline and 36months after treatment in Non F/U group(0.61+/-0.54mm) (P<0.05). 2. The changes of loss of attachment showed a statistically significant decrease between after baseline and 36months after treatment in F/U group(1.44+/-0.74mm) and did no show astatistically significant decrease between after baseline and 36months after treatment in Non F/U group(1.18+/-1.54) (P<0.05). 3. The changes of bone probing depth showed a statistically significant decrease between after baseline and 36 months after treatment in both F/U(1.35+/-0.28) and Non F/U group(0.78+/-0.55mm) (P<0.05). The results suggest that treatment of infrabony defects with bioactive glass resulted in significan reduction of attachment loss and bone probing depth 36months after the treatment. The use of bioactive glass in infrabony defects, combined with regular check-up and proper plaque control generally shows favorable clinical results. This measn that bioactive glass could be a useful bone substitute.

Clinical effects of combination anorganic bovine-derived hydroxyapatite matrix(ABM)/cell binding peptide (P-15) in periodontal intrabony defects / 대한치주과학회지

The ultimate goal of periodontal theraphy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. To achieve periodontal regeneration, various kinds of methods have been investigated and developed, including guided tissue regeneration and bone graft. Bone graft can be catagorized into autografts, allografts, xenografts, bone substitutes. And materials of all types have different biological activity and the capacity for periodontal regeneration, but ideal graft material has not been developed that fits all the requirement of ideal bone graft material. Intensive research is underway to identity, purify, synthesize a variety biologic modulators that may enhance wound healing and regeneration of lost tissues in periodontal therapy. The present study evaluates the effects of ABM/P-15 on the periodontal regeneration in intrabony defects of human. We used thirty four 2-wall or 3-wall osseous defects in premolars and molars of chronic periodontitis patient that have more than 5mm pockets and more than 3mm in intrabony defect. 12 negative control group underwent flap procedure only, 11 positive control group received DFDBA graft with flap procedure, and 11 experimental group received ABM/P-15 graft with flap procedure. The changes of probing pocket depth, loss of attachment and bone probing depth following 6months after treatment revealed the following results: 1. The changes of probing pocket depth showed a statistically significant decrease between after scaling and 6months after treatment in negative control(2.0+/-0.9mm), positive control(3.0+/-0.9mm), and experimental group (3.4+/-1.5mm) (P<0.01). Significantly more reduction was seen in experimental group compared to negative control group (P<0.05). 2. The changes of loss of attachment showed a statistically significant decrease between after scaling and 6months after treatment in positive control(2.0+/-0.6mm), and experimental group (2.2+/-1.0mm) except negative control group(0.1+/-0.7mm) (P<0.01). Significantly more reduction was seen in both experimental and positive control group compared to negative control group (P<0.05). 3. The changes of bone probing depth showed a statistically significant decrease between after scaling and 6months after treatment in positive control(2.7+/-1.0mm), and experimental group (3.4+/-1.3mm) except negative control(0.1+/-0.9mm) (P<0.01). Significantly more reduction was seen in both experimental and positive control group compared to negative control group (P<0.05). The results suggest that the use of ABM/P-15 in the treatment of periodontal intrabony defects can reduce loss of attachment and bone probing depth more than flap operation only. It suggests that ABM/P-15 may be an effective bone graft material for the regeneration of periodontal tissue in intrabony defects.

The Effects of Enamel Matrix Derivative and Calcium Sulfate Paste on the Healing of 1-Wall Intrabony Defects in Beagle Dogs / 대한치주과학회지

Recently, it was reported that enamel matrix derivative may be beneficial in periodontal regeneration procedures in expectation of promoting new bone and cementum formation. The aim of present study was to evaluate the effect of enamel matrix derivative(Emdogain?)and Caso4 sulfate paste in 1-wall intrabony defects in beagle dogs. Surgically created 1-wall intrabony defects were randomly assigned to receive root debridement alone or Emdogain(R) or Emdogain(R) and Caso4. Clinical defect size was 4 X 4mm. The control group was treated with root debridement alone,and Experimental group I was treated with enamel matrix derivative application, and Experimental group II was treated with enamel matrix derivative and Caso4 sulfate paste application,. The healing processes were histologically and histometrically observed after 8 weeks and the results were as follows : 1. The length of junctional epithelium was 0.41+/-0.01mm in the control group, 0.42+/-0.08mm in the experimental group I and 0.50+/-0.13mm in the experimental group II. 2. The connective tissue adhesion was 0.28+/-0.02 mm in the control group, 0.13+/-0.08mm in the experimental group I and 0.19+/-0.02 mm in the experimental group II. 3. The new cementum formation was 3.80+/-0.06 mm in the control group, 4.12+/-0.43mm in the experimental group I and 4.34+/-0.71mm in the experimental group II. 4. The new bone formation was 1.43+/-0.03mm in the control group, 1.53+/-0.47 mm in the experimental group I and 2.25+/-1.35mm in the experimental group II. Although there was limitation to present study, the use of enamel matrix derivative in the treatment of periodontal 1-wall intrabony defect enhanced new cementum and bone formation. Caso4 sulfate paste will be the candidate for carriers to deliver enamel matrix derivative, and so enhance the regenerative potency of enamel matrix derivative.

The effects of enamel matrix derivative on the healing of 1-wall intrabony defects in beagle dogs / 대한치주과학회지

Guided tissue regeneration, bone graft procedures, and application of growth factors have been used to regenerate lost periodontal tissues. Recently, enamel matrix derivative has been introduced into periodontal regeneration procedures in expectation of promoting new bone and cementum formation. The purpose of this study was to evaluate the effect of enamel matrix derivative in 1-wall intrabony defects in beagle dogs. For this purpose, each dog was anesthesized using intravenous anesthesia and mandibular 1st, 3rd premolars were extracted. 2 months later, the 1-wall intrabony defects(mesio-distal width; 4mm, depth; 4mm) were created on the distal side of 2nd premolars and mesial side of 4th premolars. The control group was treated with debridement alone,and experimental group was treated with debridement and enamel matrix derivative application. The healing processes were histologically and histometrically observed after 8 weeks and the results were as follows : 1. The length of junctional epithelium was 0.94+/-0.80mm in the control group, 0.57+/-0.42mm in the experimental group, with no statistically significant difference between groups. 2. The connective tissue attachment was 1.36+/-0.98mm in the control group, 0.38+/-0.43mm in the experimental group, with statistically significant difference between groups(P<0.05). 3. The new cementum formation was 2.49+/-1.06mm in the control group, 3.59+/-0.74mm in the experimental group, with statistically significant difference between groups(P<0.05). 4. The new bone formation was 1.92+/-0.97mm in the control group, 2.32+/-0.59mm in the experimental group, with no statistically significant difference between groups. Within the limitation to this study protocol, enamel matrix derivative application in 1-wall intrabony defect enhanced new cementum formation. Although there was no statistically significant difference, enamel matrix derivative also seems to be effective in inhibition of apical migration of junctional epithelium and new bone formation.

The effects of a combination of calcium sulfate and platelet-derived growth factor on periodontal ligament cells in vitro / 대한치주과학회지

It was well known that calcium sulfate was biocompatible, resorbed rapidly in the body, had potential as a good barrier membrane. Platelet-derived growth factor(PDGF) was one of polypeptide growth factor that had been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purpose of this study was to evaluate the effects of a combination of calcium sulfate and PDGF on periodontal ligament cells in vitro to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were prepared from the premolar tooth extracted for the orthodontic treatment. Cells were cultured in alpha-MEM contained with 20% FBS, at the 37degrees C, 100% of humidity, 5% Co2 incubator. Cells were inoculated and cultured into 96 well culture plate with 1x104cells/well of alpha-MEM for 1 day. After discarding the medium, those cells were cultured in alpha-MEM contained with 10% FBS alone(control group), in calcium sulfate(calcium sulfate group), in calcium sulfate treated with 15ng/ml of PDGF-BB(calcium sulfate+PDGF group), in alpha-MEM contained with 10% FBS treated with 15ng/ml of PDGF-BB(PDGF group) for 1, 2, 3 day respectively. And then each group was characterized by examining of the cell counting, MTT assay, collagen synthesis. The results were as follows. 1. In the analysis of cell proliferation by cell counting, both calcium sulfate group and calcium sulfate plus PDGF group showed no stastically significant difference compared to control group, but there was stastically significant difference between PDGF group and calcium sulfate group at 1, 2 day(P<0.05). 2. In the analysis of cell proliferation by MTT assay in calcium sulfate extracts, both calcium sulfate group and calcium sulfate plus PDGF group showed no stastically significant difference compared to control group, but there was stastically significant difference between PDGF group and calcium sulfate group at 2, 3 day, and between calcium sulfate plus PDGF group and calcium sulfate group at 2 day(P<0.05). 3. In the analysis of cell proliferation by MTT assay in transwell, both control group and PDGF group showed stastically significant difference compared to both calcium sulfate group and calcium sulfate plus PDGF group at 1 day, but there was no stastically significant difference compared to both calcium sulfate group and calcium sulfate plus PDGF group at 2, 3 day(P<0.05). 4. In the analysis of collagen synthesis by immunoblotting assay in calcium sulfate extracts, high level was detected on calcium sulfate group at 3 day, on calcium sulfate plus PDGF group at 1 day, on PDGF group at 2 day. On the basis of these results, calcium sulfate was biocompatible on the periodontal ligament cells and might have potential possibility as a vehicle of PDGF in the periodontal tissue regeneration.

The comparative study between Dura mater and Guidor(R) in the healing of the classIII furcation defects in dogs / 대한치주과학회지

There are various treatment methods including barrier membranes in attaining periodontal regeneration and regaining the function of destructed periodontal tissues due to periodontal disease.Barrier membranes consist of non-Resorbable and resorbable types such as Dura mater and Guidor(R) used in the treatment of intrabony defects and classII furcation defects have been shown to be effectively increased the amount of new bone and cementum.In our study we used premolars with class III furcation defects created by removing the bone 4mm apically from CEJ in adult dogs and placed resorbable membrane Dura mater and Guidor(R) for the test group and flap operation was carried out for the control groups. The effect of membrane on junctional epithelium, alveloar bone, cementum, and gingival connective tisssue in the regeneration and healing potential of periodontal tissues was evaluated and healing results were evaluated histologically and histometrically 8 weeks following the surgical procedure. 1. In the clinical observation, there was no exposure of furcation defects in the control group, whereas slight membrane exposure was noted in the test group. 2. New bone was formed up to the level of the notch in the control group, whereas in the test group new bone formation was observed above the level of the notch. 3. New cementum was formed in both groups of the experiment. 4. The connective tissue observed between the new cementum and new bone in the test group were functionally orientated, compared to the irregular formation of connective tissues found in the control group. 5. Root resorption or ankylosis was not observed in any of the groups 6. The mean and median of the control group were 4.31% and 2.23% and for the Dura mater group were 27.85% and 15.57% respectively. There was no significant difference between Dura mater and the control group. 7. The mean and median of the control group were 4.31% and 2.23% and for the Guidor(R) group were 37.27% and 37.19% respectively. There was a significant difference in these two groups(P<0.05). 8. The mean and median of the Dura mater group were 27.85% and 15.57% and for the Guidor(R) were 37.27% and 37.19%. There was no significant difference between the two test groups. Thus, by using Dura mater and Guidor in classIII furcation defects, the predictable amount of periodontal ligament and alveolar bone regeneration may result.

THE INFLUENCE OF POLYTETRAFLUOROETHYLENE MEMBRANE ON CELL GROWTH OF PERIODONTAL MEMBRANE AND EXPERIMENTAL REGENERATION OF PERIODONTAL TISSUE / 解放军医学杂志

The effects of polytetrafluoroethylene (e PTFE) membrane on periodontal ligament cell (PDLC) growth and periodontal tissues and new cement regeneration were studied, and the prospects of clinical application of e PTFE membrane were discussed. The results showed that PDLC grew well on the e PTFE membrane and no toxicity or inhibition was found. Close adhesion of the cells to the membrane was observed by scanning electron microscope. Histological studies suggested that the peculiar porous structure of e PTFE membrane protects and promotes healing of alveolar bone defect when the membrane edge was sealed perfectly on the crown side,exhibiting inhibition of growth of epithelium towards tooth root. The membrane was beneficial to regeneration of new alveolar bone and cement and establishment of new adhesion,and was regarded as a good substitute of old materials.