• The Korean Journal of Physiology and Pharmacology
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• 제28권5호
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• pp.423-433
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• 2024

Dental pulp stem cells (DPSCs) are a type of adult stem cell present in the dental pulp tissue. They possess a higher proliferative capacity than bone marrow mesenchymal stem cells. Their ease of collection from patients makes them well-suited for tissue engineering applications, such as tooth and nerve regeneration. Chios gum mastic (CGM), a resin extracted from the stems and leaves of Pistacia lentiscus var. Chia, has garnered attention for its potential in tissue regeneration. This study aims to confirm alterations in cell proliferation rates and induce differentiation in human DPSCs (hDPSCs) through CGM treatment, a substance known for effectively promoting odontogenic differentiation. Administration of CGM to hDPSC cells was followed by an assessment of cell survival, proliferation, and odontogenic differentiation through protein and gene analysis. The study revealed that hDPSCs exhibited low sensitivity to CGM toxicity. CGM treatment induced cell proliferation by activating cell-cycle proteins through the Wnt/β-catenin pathway. Additionally, the study demonstrated that CGM enhances alkaline phosphatase activation by upregulating the expression of collagen type I, a representative matrix protein of dentin. This activation of markers associated with odontogenic and bone differentiation ultimately facilitated the mineralization of hDPSCs. This study concludes that CGM, as a natural substance, fosters the cell cycle and cell proliferation in hDPSCs. Furthermore, it triggers the transcription of odontogenic and osteogenic markers, thereby facilitating odontogenic differentiation.

• 대한치과의사협회지
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• 제55권5호
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• pp.352-357
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• 2017

Teeth are made up of three hard tissues, enamel, dentin, and cementum. The dental pulp is the only non-mineralized connective tooth tissue that is surrounded by dentin. The dentin-pulp complex is able to respond to injury by producing hard tissue deposition. However, dentin is considered one of the most difficult tissues to regenerate because of its unique anatomic and physiologic nature. Recently, advances in understanding the applicability of bio-active dentin regenerating proteins are emerging with the development of biological-based therapies using bio-active materials. Dentin defects were regenerated by the deposition of tubular physiologic dentin after application of the bio-active protein in a beagle dog model. Therefore, the bio-active protein may be able to serve as a novel dentin regenerating material and improve symptoms of dentin hypersensitivity.

• Journal of Periodontal and Implant Science
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• 제44권3호
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• pp.147-155
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• 2014

Purpose: In the anterior maxilla, hard and soft tissue augmentations are sometimes required to meet esthetic and functional demands. In such cases, primary soft tissue closure after bone grafting procedures is indispensable for a successful outcome. This report describes a simple method for soft tissue coverage of a guided bone regeneration (GBR) site using the double-rotated palatal subepithelial connective tissue graft (RPSCTG) technique for a maxillary anterior defect. Methods: We present a 60-year-old man with a defect in the anterior maxilla requiring hard and soft tissue augmentations. The bone graft materials were filled above the alveolar defect and a titanium-reinforced nonresorbable membrane was placed to cover the graft materials. We used the RPSCTG technique to achieve primary soft tissue closure over the graft materials and the barrier membrane. Additional soft tissue augmentation using a contralateral RPSCTG and membrane removal were simultaneously performed 7 weeks after the stage 1 surgery to establish more abundant soft tissue architecture. Results: Flap necrosis occurred after the stage 1 surgery. Signs of infection or suppuration were not observed in the donor or recipient sites after the stage 2 surgery. These procedures enhanced the alveolar ridge volume, increased the amount of keratinized tissue, and improved the esthetic profile for restorative treatment. Conclusions: The use of RPSCTG could assist the soft tissue closure of the GBR sites because it provides sufficient soft tissue thickness, an ample vascular supply, protection of anatomical structures, and patient comfort. The treatment outcome was acceptable, despite membrane exposure, and the RPSCTG allowed for vitalization and harmonization with the recipient tissue.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.65-75
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• 2007

In this study, author examined the effect of the concentration of the inorganic polyphosphate on the process of the bone regeneration by using the 6 weeks old rabbit with the weight of 2.0kg in average. we performed the experiment by using TR-eITFE membrane filled with collagen immersed with 1%, 2%, and 4% of inorganic polyphosphate, respectively, after removing the proper sized cort-ical bones from the calvaria of rabbit. The experimental results were compared with the one of the following four groups: The control group for membrane only, experimental group I for membrane filled with collagen im-mersed with 1% of inorganic polyphosphate, experimental group II for membrane filled with collagen immerse with 2% of inorganic polyphosphate, experimental group III for membrane filled with colla-gen immersed with 4% of inorganic polyphosphate. The fragments of the tissue with membrane were obtained from each group of the sacrificed rab-bits for 4 or 8 weeks sustained after surgery, were then prestained and coated. New bone formation was assessed by histomorphometric and statistical analysis. We may draw the conclusions from these experiments as following: 1. Collagen was an excellent carrier with a minimal inflammatory reaction and sustaining the form. 2. The sample of the 8th week group has shown the best bone regeneration compared with the cases of all groups including the control group. 3. The samples of collagen immersed with 2% and 4% of inorganic polyphosphate have shown more bone regeneration relative to the sample of the 1% inorganic polyphosphate. 4. The new bone regeneration was shown actively in the group for membrane filled with collagen immersed with 4% of inorganic polyphosphate. With above results, it is strongly suggested the use of inorganic polyphosphate with vehicle under TR-eITFE membrane.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.285-292
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• 2008

Purpose: The present study was performed to evaluate the effect of surface treatment of the cervical area of implant on bone regeneration in fresh extraction socket following implant installation. Materials and methods: The four minipigs, 18 months old and 30 kg weighted, were used. Four premolars of the left side of both the mandible and maxilla were extracted. ${\phi}$3.3 mm and 11.5 mm long US II plus implants (Osstem Implant co., Korea) with resorbable blasting media (RBM) treated surface and US II implants (Osstem Implant co., Korea) with machined surface at the top and RBM surface at lower portion were installed in the socket. Stability of the implant was measured with $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden). After 2 months of healing, the procedures and measurement of implant stability were repeated in the right side by same method of left side. At four months after first experiment, the animals were sacrificed after measurement of stability of all implants, and biopsies were obtained. Results: Well healed soft tissue and no mobility of the implants were observed in both groups. Histologically satisfactory osseointegration of implants was observed with RBM surface, and no foreign body reaction as well as inflammatory infiltration around implant were found. Furthermore, substantial bone formation and high degree of osseointegration were exhibited at the marginal defects around the cervical area of US II plus implants. However, healing of US II implants was characterized by the incomplete bone substitution and the presence of the connective tissue zone between the implant and newly formed bone. The distance between the implant platform (P) and the most coronal level of bone-to-implant contact (B) after 2 months of healing was $2.66{\pm}0.11$ mm at US II implants group and $1.80{\pm}0.13$mm at US II plus implant group. The P-B distance after 4 months of healing was $2.29{\pm}0.13$mm at US II implants group and $1.25{\pm}0.10$mm at US II plus implants group. The difference between both groups regarding the length of P-B distance was statistically significant(p<0.05). Concerning the resonance frequency analysis (RFA) value, the stability of US II plus implants group showed relatively higher RFA value than US II implants group. Conclusion: The current results suggest that implants with rough surface at the cervical area have an advantage in process of bone regeneration on defect around implant placed in a fresh extraction socket.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권1호
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• pp.18-24
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• 2013

Purpose: This study is performed to determine the effects of titanium cap with various sizes of pores on bone formation during guided bone regeneration (GBR). Methods: Calvaria from 10 adult male rabbits were chosen as the recipient sites. A trephine bur with a diameter of 10 mm was used to form one round groove on each side of sagittal suture of the cranium, and a round bur with a diameter of 1.5 mm was used to form 6 small holes on the inner circles of round grooves to induce bleeding. In the control group, bone graft was not conducted, and closed titanium cap was fixed in the round groove. Bone graft was not performed in groups 1 and 2, but fixed on titanium caps with 0.2 mm, and 0.5 mm sized pores, respectively. For groups 3, 4, and 5, a synthetic bone graft material (${\beta}$-tricalcium phosphate, Cerasorb$^{(R)}$, Germany) was transplanted, and titanium caps without pore, with 0.2 mm and 0.5 mm sized pore were fixed, respectively. The animals were sacrificed 4 weeks after, and clinical, radiographical, and histomorphometrical evaluation of bone regeneration was performed. Results: In all groups, there were no clinical signs of infection, inflammation or wound dehiscence. Radiographic evaluation revealed well-defined semi-circular radiopacity inside the titanium cap of groups 3, 4, and 5. Histologically, the inner surface of the hemisphere was evenly lined with newly formed bone tissue, as well as grafted bone material in the group 3. In groups 4 and 5, the insertion of connective tissue was observed along the inner surface. However, the overall surface area between the grafts with different holes yielded no statistical significance in the histomorphometrical evaluation. Conclusion: Although the total area of newly formed bone showed no significant difference, excellent bone formation tendency was observed histologically when closed caps were used with bone graft was accompanied.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권6호
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• pp.332-342
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• 2019

Objectives: Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation. Materials and Methods: This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee. Results: All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissue re-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae. Conclusion: Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

• Journal of Oral Medicine and Pain
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• 제19권1호
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• pp.73-91
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• 1994

The author used rabbits in order to examine the effect of Ga-As low power generating semiconductor laser on artificially produced injuries of experimental animals. Artificially produced injuries include surgical wound of 3mm length, 2mm depth in size on ventral skin surface of rabbit and buccal mucosa, and electrical injury formed on opposite side of skin and buccal mucosa by electrical cauterization of same length and depth, and chemical injury formed by FC(Formocresol) solution applied on the anterior dorsal part of tongue. And then, on the experimental group, Ga-As laser was irradiated beginning on the day after the wound formation and continued to irradiate every each other day for five minutes. After1, 3, 6, 9, 13th day, certain number of animals of control and experimental group were sacrified, and wound site tissue was excised to make samples and was observed under light microscope. The following is the conclusions after comparing the healing procedure of experimental and control group. The following results were obtained : 1. Inflammation was decreased more rapidly in the experimental group than the control group. 2. In the surgical, the electrical and the chemical injuries in the oral mucosa, re-epithelialization was completed more rapidly in the experimental group than the control group. In the electrical injury on the skin, re-epithelialization was completed about 6 days after wound formation on both groups. 3. In the electrical and the surgical injuries on the oral mucosa, granulation tissue formation started at 3 days after injury on both groups, but in the chemical injury, it was completed about 3 days faster in the control group than the experimental group. In the surgical wound on the skin, it was completed about 9 days after injury, but faster in the experimental group. In the electrical injury on the skin, it was faster in the control group than the experimental group. 4. In the electrical and the surgical injuries on the oral mucosa, fibrosis was started at 6~9 days after injury on both groups, but regeneration of connective tissue in the experimental group was observed much more than the control group. 5. When comparing the effect of wound healing on skin and oral mucosa of control and experimental group, granulation tissue formation and re-epithelialization in the oral mucosa was more vigorous. In conclusion, the difference of timing and the sequence of wound healing process(inflammation, re-epithelialization, granulation tissue formation, fibrosis) following Laser irradiation between control and experimental group was not observed, but the healing tissue was observed much more in the Laser irradiated group.

• Journal of Korean Dental Science
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• 제9권2호
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• pp.55-62
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• 2016

Purpose: Alveolar bone develops with tooth eruption and is absorbed following tooth extraction. Various ridge preservation techniques have sought to prevent ridge atrophy, with no superior technique evident. Collagen has a long history as a biocompatible material. Its usefulness and safety have been amply verified. The related compound, atelocollagen, is also safe and displays reduced antigenicity since telopeptides are not present. Materials and Methods: The current study evaluated whether the $Rapiderm^{(R)}$ atelocollagen plug (Dalim Tissen, Seoul, Korea) improves tissue healing of extraction sockets and assessed the sequential pattern of bone regeneration using histology and microcomputed tomography in six beagle dogs. To assess the change of extraction socket, hard tissues were examined 2, 4, 6, and 8 weeks after tooth extraction. Result: The experimental groups showed better bone fill with slow remodeling process compared to the control groups although there was no statistical difference between groups. Conclusion: The atelocollagen seems to have a tendency to slow bone remodeling in the early phase of healing period and maintain remodeling capacity until late phase of remodeling. Also, use of atelocollagen increased the bone-to-tissue ratio compared to healing of untreated extraction socket.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권3호
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• pp.229-236
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• 2006

The biologic principle of guided bone regeneration(GBR) has been studied extensively in hopes of regenerating alveolar bone. Various materials have been utilized as regenerative membranes and grafting materials in implant surgery. To improve the ability of membranes, several types of membrane have been developed. Various materials have been utilized as regenerative membranes; however, all materials have disadvantages, and the ideal membrane material is yet to be identified. In these cases, a homologous gelatinized bone matrix(GBM) were used as a regenerative material in conjunction with the placement of endosseous root implants. 22 patients participated in this study, and 42 implants were inserted. The result of 1st operative surgery was uneventful, inflammatory reaction and dehiscences were not observed except for only one case. After the final protheses, all implants were functioning successfully. The major advantages in the use of GBMs for guided bone regeneration are of very wide application such as membrane and graft material, and that a second procedure to remove the material is not necessary, and the GBMs are accepted by the surrounding tissues without complications. The purpose of this study was to observe the usefulness of GBMs in dental implant surgery.