• 폴리머
• /
• 제26권1호
• /
• pp.128-138
• /
• 2002

종양부위 또는 종양을 수술로 제거한 부위에 직접 이식하여 항암제를 투여함으로써 종양 또는 종양재발을 억제하는 악성뇌종양치료에 이용하기 위한 국소서방성 항암제제로서 항암제 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine)가 함유된 poly(D,L-lactide-co-glycolide) (PLGA, 락타이드와 글리콜라이드 몰비 75 : 25) 미분말을 제조하여 웨이퍼로 성형하였다. BCNU가 함유된 PLGA 미분말은 분사건조법에 의해 제조하였으며 주사전자현미경으로 관찰한 결과 제조된 미분말은 미립구의 형태를 나타내었다. XRD와 DSC를 통하여 PLGA에 포접된 BCNU의 결정성이 현저히 감소하였음을 확인하였다. 생체외 방출시험조건에서 BCNU의 방출경향은 PLGA의 분자량 및 농도, BCNU의 함량 등에 의존하였으며 초기 burst effect 이후 거의 0차 방출의 경향으로 8주 이상 지속적인 방출경향을 나타내었다. 방출시험기간 동안 웨이퍼의 형태변화를 관찰하고 방출시험액의 pH 변화를 측정함으로써 BCNU의 함량이 증가할수록 PLGA의 수화와 분해가 촉진됨을 확인하였다.

• Restorative Dentistry and Endodontics
• /
• 제18권1호
• /
• pp.205-213
• /
• 1993

The purpose of the study was to evaluate the degree of the marginal leakage of esthetic restorative materials on root caries restoration. 120 cavities were prepared to $90^{\circ}$ butt joint on all margins on the crown and root portion, and divided into 4 groups. The four groups of cavity were filled with Amalgam(Dongmuyung Dental Alloy Co., Ltd, KOREA), Silux$^{(R)}$(3M Co., USA)-Scotch Bond 2$^{(R)}$(3M Co., USA), Silux$^{(R)}$-All Bond$^{(R)}$(BISCO USA), and GC Fuji II$^{(R)}$(G-C Co., JAPAN) respectively. The apical margin of the preparation was finished to leave a flash of restorative material. The coronal margin of the preparation was finished not to leave a flash of restorative material. All specimens were sectioned longitudinally with Isomet Low speed saw(Buether Ltd, USA). The degree of dye penetration was evaluated as the parameter of marginal leakage under the stereoscope. The results were as follows. 1. At the enamel and dentin/cementum margins, the margin were finished to leave a flash of material showed less marginal leakage than that were finished not to leave a flash of material (P<0.001). 2. The enamel margins showed less marginal leakage than the dentin/cementum margins(P<0.001). 3. There was no significant difference in the degree of the marginal leakage between Silux$^{(R)}$-Scotch Bond 2$^{(R)}$ group and Silux$^{(R)}$-All Bond$^{(R)}$ group.

• Journal of Periodontal and Implant Science
• /
• 제52권5호
• /
• pp.411-421
• /
• 2022

Purpose: In this study, we aimed to evaluate the degree of heat generation when a novel drill design with an irrigation slot was used with metal sleeve-free (MF) and metal sleeve-incorporated (MI) surgical guides in an environment similar to that of the actual oral cavity. Methods: A typodont with a missing mandibular right first molar and 21 bovine rib blocks were used. Three-dimensional-printed MF and MI surgical guides, designed for the placement of internal tapered implant fixtures, were used with slot and non-slot drills. The following groups were compared: group 1, MI surgical guide with slot drill; group 2, MI surgical guide with a non-slot drill; and group 3, MF surgical guide with a slot drill. A constant-temperature water bath at 36℃ was used. The drilling was performed in 6 stages, and the initial, highest, and lowest temperatures of the cortical bone were measured at each stage using a non-contact infrared thermometer. Results: There were no temperature increases above the initial temperature in any drilling procedure. The only significant difference between the non-slot and slot groups was observed with the use of the first drill in the MI group, with a higher temperature in the non-slot group (P=0.012). When the heat generation during the first and the second drilling was compared in the non-slot group, the heat generation during the first drilling was significantly higher (P<0.001), and there was no significant difference in heat generation between the drills in the slot group. Conclusions: Within the limitations of this study, implant-site preparation with the surgical guide showed no critical increase in the temperature of the cortical bone, regardless of whether there was a slot in the drill. In particular, the slotted drill had a cooling effect during the initial drilling.

• 대한소아치과학회지
• /
• 제23권3호
• /
• pp.746-763
• /
• 1996

An alternative design to conventional class II cavity preparation for proximal carious lesions is the tunnel preparation. It preserves the marginal ridge intact, thus making it possible to maintain the natural contact relationship with the adjacent tooth and minimize tooth reduction. This in vitro study was purposed to evaluate the effect of the materials' elastic constants and shear-bond strength on the marginal ridge fracture resistance of teeth restored by the tunnel technique, and to find the materials of choice for tunnel restorations. $Resinomer^{(R)}$, $Ketac-silver^{(R)}$, $Miracle-Mix^{(R)}$, and Tytin were used as restorative material. The elastic constants of each restorative material were evaluated by ultrasonic pulse measurement. Young's modulus and bulk modulus of the restorative materials were evaluated in three specimens for each material type. The shear-bond strength of the restorative materials to the dentin surface was measured after thermocycling 400 times between 6 and $60^{\circ}C$, using ten specimens for each material type. For measuring marginal ridge strength, 60 sound extracted molar teeth were distributed into six groups by size. Sound molar teeth were used as a Control group and unfilled prepared teeth were grouped as Unrestored. Another four groups were named Resinomer group, Ketac-Silver group, Miracle Mix group, and Tytin group by type of restorative material. Tunnel cavity preparation was done with ' 1/2, 2, and 4 round burs in sequence. Initial access to proximal surface was made through an occlusal access preparation started at least 2mm from the marginal ridge, and the proximal opening was formed about 2.5mm below the marginal ridge. After restoration and thermocycling, marginal ridge strength was measured using a universal testing machine. The results were as follows: 1. The Young's modulus of $Tytin^{(R)}$ was 63.95 GPa, followed by $Ketac-Silver^{(R)}$ 27.60 GPa, $Miracle-mix^{(R)}$ 18.48 GPa, and $Resinomer^{(R)}$ 10.74 GPa showing significant differences between the groups(P<0.05). The bulk modulus of the materials showed the same order as Young's modulus. The value of $Tytin^{(R)}$ showed 59.57 GPa indicating that it will deform less than other materials under the same stress. It was followed by $Ketac-Silver^{(R)}$ 23.57 GPa, Miracle $Mix^{(R)}$ 12.50 GPa, and $Resinomer^{(R)}$ 11.60 GPa. 2. The Resinomer group had a shear-bond strength of 7.41 MPa which was significantly higher than those of the Ketac-Silver group (1.80 MPa) and the Miracle Mix group (2.84 MPa) (P<0.01). All the specimens of Tytin group detatched from the dentin surface during thermocycling. 3. The mean marginal ridge strength of the Unrestored group(46.14 kgf) was significantly lower than that of the Control group (84.24 kgf) (P<0.01). The marginal ridge strength of teeth restored by the tunnel technique was, in order, Ketac-Silver group 74.06 kgf, Miracle Mix group 73.36 kgf, Resinomer group 63.47 kgf, and Tytin group 58.76 kgf. The Ketac-Silver, Miracle Mix, and Resinomer groups showed no significant difference with the Control group (P>0.05), but the Tytin group showed significantly lower strength compared to the Control group(P<0.05). The results showed that the marginal ridge strength of the teeth restored by the tunnel technique was not significantly lower than that of sound teeth. They also demonstrated that the bonding strength of the restorative material to the tooth surface should be high and the modulus of elasticity should not be lower than that of the tooth in order to restore the marginal ridge strength to its natural condition.

• Restorative Dentistry and Endodontics
• /
• 제14권2호
• /
• pp.1-4
• /
• 1989

To determine the thickness of coronal hard structure the minimal distance between pupal surface and outer surface of crown was measured by means of Bowley gauge on extracted first molars. Upper(28 teeth) and lower(24 teeth) were carefully collected from 30-39 years of age and male. The teeth were split mesio-distally through central pit. On the split surface various part which are deeply related in cavity preparation were measured (schematic drawing). The results were as follows: A : Distance from mesio-cervical enamel to pulp chamber surface. upper $2.63{\pm}0.19$(mm) Lower $2.18{\pm}0.27$(um) B : Distance from mesial chamber ceiling to mesial surface upper $2.75{\pm}0.34$ Lower $2.62{\pm}0.31$ C : Distance from mesial chamber ceiling to occlusal surface upper $3.82{\pm}0.51$ Lower $3.49{\pm}0.50$ D : Distance from distal chamber ceiling to occlusal surface upper $4.28{\pm}0.69$ Lower $3.90{\pm}0.52$ E : Distance from distal chamber ceiling to distal surface upper $2.79{\pm}0.45$ Lower $2.41{\pm}0.40$ F : Distance from disto cervical enamel to pulp chamber surface upper $2.49{\pm}0.24$ Lower $2.39{\pm}0.25$.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제17권4호
• /
• pp.281-287
• /
• 2017

Background: Various techniques have been introduced to decrease complications during nasotracheal intubation. A common practice is to use nasal packing with a cotton stick and 0.01% epinephrine jelly. However, this procedure can be painful to patients and can damage the nasal mucosa. Xylometazoline spray can induce effective vasoconstriction of the nasal mucosa without direct nasal trauma. In this study, we aimed to compare the efficacy of these two methods. Methods: Patients were randomly allocated into two groups (n = 40 each): xylometazoline spray group or epinephrine packing group. After the induction of general anesthesia, patients allocated to the xylometazoline spray group were treated with xylometazoline spray to induce nasal cavity mucosa vasoconstriction, and the epinephrine packing group was treated with nasal packing with two cotton sticks and 0.01% epinephrine jelly. The number of attempts to insert the endotracheal tube into the nasopharynx, the degree of difficulty during insertion, and bleeding during bronchoscopy were recorded. An anesthesiologist, blinded to the intubation method, estimated the severity of epistaxis 5 min after intubation and postoperative complications. Results: No significant intergroup difference was observed in navigability (P = 0.465). The xylometazoline spray group showed significantly less epistaxis during intubation (P = 0.02). However, no differences were observed in epistaxis 5 min after intubation or postoperative epistaxis (P = 0.201). No inter-group differences were observed in complications related to nasal intubation and nasal pain. Conclusion: Xylometazoline spray is a good alternative to nasal packing for nasal preparation before nasotracheal intubation.

• 한국식품조리과학회지
• /
• 제11권1호
• /
• pp.69-76
• /
• 1995

Chou에 있어서 원료소맥분에 대한 미분의 대체 가능성을 검토하기 위하여, 중력분에 미분을 0, 25, 50, 75, 100% 첨가한 미분 및 미분복합분에 대한 원료전분별 이화학적특성과 chou형성능력을 조사하고, 반죽의 물리적성질을 개량하기 위하여 증점제인 젤라틴과 유화제 Span20을 첨가한 후 첨가제의 효과를 비교검토하였다. 미분의 물결합능력과 팽윤력은 280%, 28.8로서 중력분 234%, 12.1보다 컸다. 미분과 중력분 호화개시온도는 $65^{\circ}C$로서 동일하였으며, 최고점도는 미분이 중력분보다 컸다. 냉각시의 setback율은 미분은 0.94, 중력분은 1.14로서 미분은 중력분보다 노화가 느린 것으로 판단된다. 중력분에 미분을 혼합한 경우, chou형성은 미분의 혼합비율에 따라 중력분 chou의 80.0-89.0%로 감소하였다. 그러나, 미분에 증점제와 유화제를 첨가하면 chou형성은 무첨가구에 비하여 각각 108.8%, 126.4%로 향상되었다. Chou반죽을 냉동처리할 경우, 반죽제조직 후 구운 chou와 비교하여 차이가 없었다. Chou반죽의 내부구조를 광학 현미경으로 관찰하였던 바, 미분의 반죽내의 원료성분들의 분산은 양호하였으나, 조직이 치밀하였다. 따라서, 유지의 입자는 작고, 함유량도 적었다. 그러나, 미분에 증점제나 유화제를 첨가한 반죽은 원료성분의 분산이 우수하였다. 특히, 유화제 첨가의 경우, 유화가 잘되어 소립의 유지입자가 고르게 다량 함유되어 있었다. 관능검사 결과에서 25%미분복합분, 50%미분복합분, 75%미분복합분의 chou들은 중력분과 비교하여 외형, 외부색, 공동형성, 저작감, 맛의 모든 항목에서 같거나 좋은 평가를 받았다. 100%미분의 chou는 공동형성에서만 100%중력분 chou에 비하여 다소 떨어졌을 뿐, 나머지 항목에서는 유의차가 없었다. 본 실험의 결과로부터 100%미분의 chou는 공동상팽화능력만 다소 떨어졌을 뿐, 맛은 소맥분과 비교하여 큰 차이가 없었던 것으로 나타나, chou제조에 있어서 미분은 소맥분과 대체하여 충분히 사용할 수 있는 것으로 판단된다. 한편, 증점제나 유화제를 첨가함으로써 미분 및 미분복합분의 chou형성능력이 크게 향상되었던 것으로 보아 향후, 이들 첨가제의 종류와 첨가량에 대한 연구 검토가 진행되어야 할 것으로 생각된다.

• Applied Microscopy
• /
• 제31권2호
• /
• pp.109-116
• /
• 2001

홍화씨는 예로부터 국내에서 재배되어 한방 및 민간에서 특히 뼈에 우수한 작용이 있는 것으로 생각되어 오랫동안 복용되어 왔다. 최근 홍화씨를 성분분석한 바에 의하면 칼륨과 마그녜슘, 칼슘이 다량 함유되어 있어서 뼈의 발달과 유지에 도움이 있을 것이라고 추측된다. 그러나 아직까지 확실한 실험적 자료가 제시된 것은 별로 없다. 이에 저자들은 홍화씨 분말이 골다공증의 예방에 미치는 효과를 알아보기 위하여 본 실험을 실시하였다. 실험동물은 체중 230g의 12주령의 Sprague-Dawley Rats를 사용하였으며, 양쪽난소를 제거한 후 홍화씨 분말을 매일 0.3g씩 복용시키면서 1, 3, 5 및 7주 후에 경골을 채취하여 관찰하였다. 채취된 조직은 통상적인 주사전자현미경 시료제작법으로 고정과정을 거친 후 10% 질산으로 12시간 탈회하여 뼈의 단면을 노출시키고 탈수, 건조 및 금도금 과정을 거쳐 주사전자현미경(Hitachi, S-450)으로 관찰하여 촬영하였다. 관찰결과 난소적출 후 골소실이 일어나기 시작하여 7주 후에 대조군은 골수강에서 피질골까지의 두께의 감소와 골수강의 확장이 심하였으나, 홍화씨 분말을 투여한 실험군에서는 1주에서 7주까지 거의 같은 소견을 나타내었다. 이상의 결과를 종합해보면 홍화씨 분말은 여성호르몬 결핍으로 인한 골다공증의 예방에 효과가 있는 것으로 사료된다.

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

• 구강회복응용과학지
• /
• 제30권2호
• /
• pp.145-151
• /
• 2014

목적: 본 연구는 두가지 다른 방법에 의한 레진강화형 글래스 아이오노머(RMGI) 이장재의 적용이 2급와동 복합레진수복의 미세누출에 미치는 영향을 조사하고자 하였다. 연구 재료 및 방법: 36개의 발치한 치아에 2급 와동을 형성한 뒤 무작위로 3개의 군으로 나누었다. 1군은 대조군으로 이장재를 적용하지 않았으며, 2군은 치과용 탐침으로 RMGI 이장재 적용, 3군은 특별히 고안된 버로 RMGI 이장재를 적용한 뒤 복합레진은 똑같이 통상적인 방법으로 적층수복하였다. 2% 메틸렌 블루 염색한 뒤 치아장축과 평행하게 순설 방향으로 절단하여 미세누출을 현미경과 컴퓨터 프로그램을 사용하여 분석을 하였다. 데이터는 Kruskal-Wallis test와 Mann-Whitney U-test (P < 0.05)로 분석하였다. 결과: RMGI 이장재가 적용된 군은 그렇지 않은 군보다 월등히 적은 미세누출을 보였으며, 특히 특수 고안된 버를 사용한 군의 50%에서는 전혀 미세누출을 보이지 않았다. 그러나, 2군과 3군의 결과에서 통계적으로 유의한 차이는 관찰되지 않았다. 결론: 2급와동의 복합레진 수복에서 RMGI 이장재는 그 적용 방법에 관계없이 미세누출을 감소시키는데 효과적인 재료이다.