• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권4호
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• pp.279-288
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• 2007

In the present study, we focused on stem cells in the dental papilla of the tooth germ. The tooth germ, sometimes called the tooth bud, is the primordial structure from which a tooth is formed. The tooth germ consists of the enamel organ, the dental papilla, and the dental follicle. The dental papilla lies below a cellular aggregation of the enamel organ. Mesenchymal cells within the dental papilla are responsible for formation of dentin and pulp of a tooth. Tooth germ disappears as a tooth is formed, but that of a third molar stays in the jawbone of a human until the age of 10 to 16, because third molars grow slowly. Impacted third molar tooth germs from young adults are sometimes extracted for orthodontic treatment. In the present study, we evaluated the osteogenic activity and mineralization of cultured human dental papilla-derived cells. Dental papillas were harvested from mandible during surgical extraction of lower impacted third molar from 3 patients aged 13-15 years. After passage 3, the dental papilla-derived cells were trypsinized and subsequently suspended in the osteogenic induction DMEM medium supplemented with 10% fetal bovine serum, 50 g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate at a density of $1\;{\times}10^6\;cells/dish$ in a 100-mm culture dish. The dental papilla-derived cells were then cultured for 6 weeks and the medium was changes every 3 days during the incubation period. Dental papilla-derived cells showed positive alkaline phosphatase (ALP) staining during 42 days of culture period. The formation of ALP stain showed its maximal manifestation at day 7 of culture period, then decreased in intensity during the culture period. ALP mRNA level was largely elevated at 1 weeks and gradually decreased with culture time. Osteocalcin mRNA expression appeared at day 14 in culture, after that its expression continuously increased in a time-dependent manner up to day 28. The expression remained constant thereafter. Runx2 expression appeared at day 7 with no detection thereafter. Von Kossa-positive mineralization nodules were first present at day 14 in culture followed by an increased number of positive nodules during the entire duration of the culture period. Osteocalcin secretion was detectable in the culture medium from 1 week. The secretion of osteocalcin from dental papilla-derived cells into the medium greatly increased after 3 weeks although it showed a shallow increase by then. In conclusion, our study showed that cultured human dental papilla-derived cells differentiated into active osteoblastic cells that were involved in synthesis of bone matrix and the subsequent mineralization of the matrix.

• 대한소아치과학회지
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• 제45권2호
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• pp.215-224
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• 2018

인구통계적 변화 및 사회 경제적 변화 등으로 인해 최근 몇십 년간 소아치과는 환자 분포와 진료 양상에 많은 변화가 있었다. 본 연구는 이러한 변화의 양상을 파악하기 위해 시행되었다. 2006년부터 2015년까지 서울대학교 치과병원 소아치과에 내원한 모든 환자를 대상으로 하여 환자분포 및 진료 현황에 대한 정보를 분석하였다. 조사 결과 전체 환자 중 초진 환자의 비율은 증가하였고, 초진 환자의 평균 연령은 감소하였다. 연도별 진료 현황을 조사한 결과 2006년에는 수복치료, 예방치료, 교정치료, 외과치료, 치수치료 순으로 빈도가 높았다. 이후 예방치료는 크게 증가했고, 수복치료는 감소하였고, 치수치료 및 외과치료는 비슷하게 유지되었다. 교정치료는 2009년까지 증가하였으며 이후로는 감소하였다. 그 결과 2015년에는 예방치료, 수복치료, 교정치료, 외과치료, 치수치료 순으로 많이 시행되었다. 진정법과 전신마취 시행 건수를 년도별로 조사한 결과 2011년 이후 전신마취 시행이 크게 증가하였으며, 진정법은 2010년 크게 증가하였다가 이후 감소하여 매년 200건 정도가 시행되었다. 전체 진료 항목 중 급여 진료는 2009년까지 감소하였으며, 이후 증가하였다.

• 대한치과교정학회지
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• 제34권6호
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• pp.506-513
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• 2004

본 연구는 하치조신경의 수술적 절단이 치주인대공간에서의 파골세포에 미치는 영향을 평가하기 위하여 시행하였다. 이를 위하여 실험동물을 젊은 쥐 군 과 성 쥐 군으로 구분하여 좌측 하악골에는 하치조신경절단을 시행하여 실험측으로, 우측하악골은 가수술측으로 사용하였다. Bundle 골 표면에 위치한 파골세포의 수 그리고 파골세포의 골 흡수 활성도를 조직 형태적으로 측정하였다. 또한 Substance P 면역반응 신경섬유의 분포 변화를 치주인대와 치 수조직에서 평가하였다. Substance P 면역반응 신경섬유는 양군 실험측에서 고갈됨으로서 하치조신경의 수술적 절단이 성공적이었다는 것을 확인 할 수 있었다 실험측에서 파골세포의 수가 젊은 쥐 군 과 성 쥐 군 모두에서 유의하게 감소하였다(p<0.01과 p<0.05). 그러나 파골세포의 골 흡수 활성도는 양군 모두에서 실험측과 가수술측 사이에 차이를 나타내지 않았다(P>0.05). 성 쥐 군에서 파골세포의 수가 젊은 쥐 군에 비해 유의하게 감소되었으며 (p<0.01), 파골세포의 골 흡수 활성도에서는 변화가 없었다(p>0.05). 이들 결과를 통하여 감각신경인 하치조신경의 절단과 연령증가는 치주인대 공간에서 Bundle골 표면의 파골세포의 수를 감소시켰으며 골 흡수 활성도에는 영향을 주지 않는 것으로 나타났다.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 춘계학술대회
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• pp.247-251
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• 2001

;A dental developmental anomaly is defined as an isolated aberration in tooth form, caused by a disturbance or abnormality which occurred during tooth development. There are numerous types of dental anomalies, and a considerable variation in the extent of the defects occurs with each type. Teeth with these anomalies pose unique challenges. Since the defects are not always apparent clinically, they can confuse diagnosticians investigating the etiology of pulpal pathosis. When endodontic treatment is required, the defects often hinder access cavity preparation and canal instrumentation. Treatment planning also becomes more challenging, since the defects can create complicated periodontal problems, and the malformed teeth can be difficult to restore, particularly those weakened by endodontic therapy. Fusion is defined as the joining of two developing tooth germs resulting in a single large tooth structure. The incidence of fusion is < 1% in the Caucasian population, and it is believed that physical force or pressure produces contact of the developing teeth. Clinically and radiographically, a fused tooth usually appears as one large crown with at least partially separated roots and root canals. There may be a vertical groove in the tooth crown delineating the originally separate crowns. Dens invaginatus is a deep surface invagination of the crown or root that is lined by enamel. Teeth in both maxillary and mandibular arches may be affected, but the permanent maxillary lateral incisor is the tooth most commonly involved. Studies have revealed an incidence ranging from 0.25% to as high as 10%. The invagination ranges from a slight pitting to an anomaly occupying most of the crown and root. The invagination frequently communicates with the oral cavity, allowing the entry of irritants and microorganism either directly into pulpal tissues or into an area that is deparated from pulpal tissues by only a thin layer of enamel and dentin. This continuous ingress of irritants and the subsequent inflammation usually lead to necrosis of the adjacent pulp tissue and then to periapical or periodontal abscesses. If the invagination extends from the crown to the periradicular tissue and has no communication with the root canal system, the pulp may remain vital. Recommended treatment of fused tooth and dens invaginatus has been reported in the endodontic literature. This case report describes the endodontic treatment of a maxillary laterl incisors having fused crown and dens invaginatus.natus.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.735-750
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• 2018

BACKGROUND: The major challenge of tissue engineering is to develop constructions with suitable properties which would mimic the natural extracellular matrix to induce the proliferation and differentiation of cells. Poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone) (PCL-PEG-PCL, PCEC), chitosan (CS), nano-silica ($n-SiO_2$) and nano-hydroxyapatite (n-HA) are biomaterials successfully applied for the preparation of 3D structures appropriate for tissue engineering. METHODS: We evaluated the effect of n-HA and $n-SiO_2$ incorporated PCEC-CS nanofibers on physical properties and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Fourier transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope, thermogravimetric analysis, contact angle and mechanical test were applied to evaluate the physicochemical properties of nanofibers. Cell adhesion and proliferation of hDPSCs and their osteoblastic differentiation on nanofibers were assessed using MTT assay, DAPI staining, alizarin red S staining, and QRT-PCR assay. RESULTS: All the samples demonstrated bead-less morphologies with an average diameter in the range of 190-260 nm. The mechanical test studies showed that scaffolds incorporated with n-HA had a higher tensile strength than ones incorporated with $n-SiO_2$. While the hydrophilicity of $n-SiO_2$ incorporated PCEC-CS nanofibers was higher than that of samples enriched with n-HA. Cell adhesion and proliferation studies showed that n-HA incorporated nanofibers were slightly superior to $n-SiO_2$ incorporated ones. Alizarin red S staining and QRT-PCR analysis confirmed the osteogenic differentiation of hDPSCs on PCEC-CS nanofibers incorporated with n-HA and $n-SiO_2$. CONCLUSION: Compared to other groups, PCEC-CS nanofibers incorporated with 15 wt% n-HA were able to support more cell adhesion and differentiation, thus are better candidates for bone tissue engineering applications.

• 대한소아치과학회지
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• 제50권3호
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• pp.307-317
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• 2023

심미성에 대한 요구가 증가함에 따라 유구치 수복을 위한 지르코니아 전장관은 더 활발하게 사용되고 있으나, 지르코니아 전장관으로 수복한 치아를 장기간 추적 관찰하거나 다른 재료와 비교한 연구는 많지 않다. 따라서 이 연구의 목적은 인접면 우식증에 대한 지르코니아 전장관과 기성금속관의 36개월 동안의 생존율을 비교하여 평가하고, 각 기성관의 수복 실패 양상을 분석하는 것이다. 2017년부터 2019년까지 조선대학교 치과병원 소아치과와 두 개의 개인 치과의원에 내원하여 두 기성관으로 수복 치료를 받은 498명 환자에 대한 1,061개의 유구치에 대한 전자의무기록지와 방사선 사진을 수집하고 분석하였다. 생존분석 결과, 기성금속관으로 수복한 치아의 생존율이 지르코니아 전장관에 비해 유의하게 높았다. 치수 치료 시행 여부를 나눠 생존 분석을 시행한 결과, 치수 치료를 시행하지 않은 경우, 기성금속관의 생존율이 지르코니아 전장관에 비해 유의하게 높았던 반면, 치수 치료를 시행한 경우에는 두 기성관의 생존율에 유의한 차이가 없었다. 기성금속관의 주된 수복실패 원인은 비정상적 치근 흡수 또는 치근단 투과상 병소의 발생이었고, 지르코니아 전장관의 경우 수복물의 탈락이었다. 이 연구는 임상가들에게 구치부 기성관 재료 선택 시 참고 자료로 활용될 수 있을 것이라 생각된다.

• 대한소아치과학회지
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• 제45권1호
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• pp.75-81
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• 2018

최근 진정법은 소아치과의 영역에서 협조도가 부족한 어린이를 대상으로 흔히 사용되고 있다. 본 연구의 목적은 5년간 단국대학교 치과병원 소아 치과에서 시행된 진정법에 대한 정보를 다각도로 분석하는 것이다. 종합의료정보시스템(Order Communication System)을 사용하여 2011년 1 월부터 2015년 12월까지 단국대학교 치과병원 소아치과에서 시행된 치과 치료에 대한 정보를 수집하였다. 수집된 정보는 환자의 성별, 연령, 진정법 시행여부 및 약물 종류, 시술 날짜 및 유형이었다. 전체 증례에 대한 의식하진정법 사용 증례의 비율은 2011년에서 2014년까지 지속적으로 감소하였다. 반면 전신마취 증례의 빈도는 점진적으로 증가하였다. 의식하진정 유도를 위한 방법 중 midazolam 근육주사와 아산화질소 흡입진정의 사용빈도는 최근 증가하였다. 의식하진정법의 사용은 환아의 나이가 만3세 이상인 경우 그 빈도가 크게 감소하였으나, 전신마취는 전 연령대에서 사용 빈도가 비슷하였다. 환아가 여아인 경우보다 남아인 경우에, 그리고 수복치료만을 시행하는 경우보다 신경치료를 함께 시행하는 경우에 더 깊은 진정 상태에서 치료를 시행하려는 경향이 관찰되었다. 또한 진정의 심도가 깊을수록 수복치료 이후 90일 이내에 재치료를 시행하는 빈도는 감소하였다.

• 대한소아치과학회지
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• 제11권1호
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• pp.169-179
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• 1984

The purpose of this study was to observe the effect of dental varnish applied with fluoride to dental pulp by comparing the groups of commercial fluoride product $Duraphat^{(R)}$, $Copalite^{(R)}$ after 1 Mole sodium fluoride application, Cavity $Sealer^{(R)}$ after 1 Mole sodium fluoride application with the control group not applied the dental varnish. After Cl V Cavity form was prepared on the buccal surface of the crowns with the total 75 teeth by using 5 dogs, average weight of 13.2Kg, dental varnish and silver analgram were placed. This study was performed by 3, 7, 21, 28, 56 days each. The dogs were sacrificed to extract the teeth, cut at the apical one fourth, and prepared histologic examination by fixing with 10% buffered formalin perfusion at sacrifice and decalcification in 10% nitric acid. The specimens were embedded in paraffin, stained with Hematoxylin and Eosin, and serially sectioned with 6 ${\mu}$width each. Microscopic evaluation of serial sections at the various time periods among the different groups revealed the following results: 1. In the control group, the marked change of the odontoblastic layer was showed on the 3 days group, and it was decreased gradually. Healing response, such as hyperplasia, was seen on the 28 days group and it was continued to the 56 days group. 2. In the experimental group with Cavity $Sealer,^{(R)}$ a slight hemorrhage was seen in the odontoblastic layer on the 3 days group, and the healing response with the hyperplasia of the odontoblast was showed on the 21, 28 days group. It was completely healed on the 56 days group. 3. In the Duraphat R group, a slight hemorrhage showed on the 3 days group and the disarrangement of the Odontoblastic layer was seen on the 7, 21, 28 days group. Odontoblasts showed hyperplasia on the 28 days group, and healed completely on the 56 days group. 4. In the $Copalite^{(R)}$ group, the 7 days group showed remarkable hemorrhage in the odontoblastic layer and stroma, and also it showed reticular degeneration with the disarrangement of the odontoblastic layer and congestion. Each group showed disarrangement. Healing ability of this group was greater than that of the control group, but less than that of the $Duraphat^{(R)}$ and Cavity $Sealer^{(R)}$ group.

• 대한소아치과학회지
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• 제39권4호
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• pp.397-403
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• 2012

미성숙 영구치는 치아우식증, 외상, 비정상적인 치아 형태로 인한 파절 등에 의하여 치수 생활력을 상실할 수 있다. 이때 이용되는 치료법이 치근단 형성술로서 실활치의 치근단 치수 부위에 광화된 조직의 형성을 통하여 치근단 폐쇄를 유도한다. 현재 수산화칼슘 치근단 형성술이 가장 많이 이용되는데 근관 내에 수산화칼슘을 장기간 적용할 경우 치근단 경조직 형성을 유도할 수 있지만, 강한 알칼리성으로 인하여 치근 약화를 야기하여 치아 파절 위험성이 높아진다. 그러므로 근관 충전 시 치아보강을 위한 수복이 고려되어야 한다. 본 증례는 생활력을 상실한 미성숙 영구치에서 장기간의 수산화칼슘 치근단 형성술 후 치아 보강을 위하여 MTA plug, 섬유강화형 포스트 그리고 복합 레진을 이용한 근관 충전을 시도하였기에 보고하는 바이다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권4호
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• pp.305-314
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• 2022

Introduction: This clinical trial aimed to evaluate the anesthetic effect of the addition of 2 mg (4 mg/ml) of dexamethasone to 2% lidocaine (plain or with 1:80,000 epinephrine). The solutions were injected for a primary inferior alveolar nerve block (IANB) to provide mandibular anesthesia for the endodontic treatment of mandibular molars with symptomatic irreversible pulpitis. Methods: In a double-blinded setup, 124 patients randomly received either of the following injections: 2% lidocaine with 1:80,000 epinephrine, 2% lidocaine with 1:80,000 epinephrine mixed with 2 mg dexamethasone, or plain 2% lidocaine mixed with 2 mg dexamethasone, which were injected as a primary IANB. Ten minutes after injection, patients with profound lip numbness underwent electric and thermal pulp sensibility tests. Patients who responded positively to the tests were categorized as "failed" anesthesia and received supplemental anesthesia. The remaining patients underwent endodontic treatment using a rubber dam. Anesthetic success was defined as "no pain or faint/weak/mild pain" during endodontic access preparation and instrumentation (HP visual analog scale score < 55 mm). The effect of the anesthetic solutions on the maximum change in heart rate was also evaluated. The Pearson chi-square test at 5% and 1% significance was used to analyze anesthetic success rates. Results: The 2% lidocaine with 1:80,000 epinephrine, 2% lidocaine with 1:80,000 epinephrine mixed with 2 mg dexamethasone, and plain 2% lidocaine mixed with 2 mg dexamethasone groups had anesthetic success rates of 34%, 59%, and 29%, respectively. The addition of dexamethasone resulted in significantly better results (P < 0.001, 𝛘² = 9.07, df = 2). Conclusions: The addition of dexamethasone to 2% lidocaine with epinephrine, administered as an IANB, can improve the anesthetic success rates during the endodontic management of symptomatic mandibular molars with irreversible pulpitis.