서로 다른 근관세척제에서 전자 근관장 측정기의 정확도 평가

장훈상(Hoon-Sang Chang),박세희(Se-Hee Park),조경모(Kyung-Mo Cho),김진우(Jin-Woo Kim) 대한턱관절교합학회 2012 구강회복응용과학지 Vol.28 No.2

CBCT와 치과용 현미경을 이용한 C형 근관을 가지는 하악 제1소구치의 근관치료

장훈상(Hoon-Sang Chang),김민정(Min-Jeong Kim),이석련(Seok-Ryun Lee),홍성옥(Sung-Ok Hong) 대한턱관절교합학회 2014 구강회복응용과학지 Vol.30 No.4

The instrument-centering ability of four Nickel-Titanium instruments in simulated curved root canals

구재훈,장훈상,장석우,조환희,배지명,민경산,Ku, Jae-Hoon,Chang, Hoon-Sang,Chang, Seok-Woo,Cho, Hwan-Hee,Bae, Ji-Myung,Min, Kyung-San The Korean Academy of Conservative Dentistry 2006 Restorative Dentistry & Endodontics Vol.31 No.2

본 연구의 목적은 새로 시판된 NRT 기구의 근관 형태 유지 능력을 기존의 3종의 기구와 비교하는 것이다. 만곡된 레진 모형 근관을 ProFile, K3, ProTaper, NRT 기구를 이용하여 형성하였고 형성 전, 후의 상을 스캔한 후 중첩시켜 이미지 분석 프로그램을 이용하여 근관 만곡도의 변화와 근관 중심축에 대한 근관의 변이 정도를 근관 중심율의 변화로 계산하여 분석하였다. 근관 변이의 유의성 검정을 위해 one-way ANOVA분석을 시행하였으며 각 기구간의 유의성 검정은 Duncan's test로 사후 분석하였다. 근첨에서 1, 2 mm 상방 위치에서의 근관 중심율은 ProFile 군이 다른 군에 비해 우수한 것으로 나타났다. (p < 0.05). NRT기구의 근관 중심율 변화를 측정한 결과 근첨으로부터 5 mm 상방에서는 Profile에 비해서만 큰 것으로 나타났고 6, 7 mm 상방에서는 다른 모든 군들에 비해 큰 것으로 나타났다 (p < 0.05). 비록 NRT기구가 근첨 부위에서는 ProFile을 제외한 다른 기구에 비해 유의차 없는 중심률 유지 능력을 보였으나 근관 입구 및 중간부위의 형성에 사용되는 스테인레스-스틸 파일로 인해 coronal flaring시 다른 기구들에 비해 더 많은 중심률의 변화를 보이는 것으로 사료된다. The aim of this study was to evaluate the ability of newly marketed NRT instruments to maintain the original root canal configuration and curvature during preparation in comparison with the three existing instruments in simulated root canals. Simulated canals in resin blocks were prepared with ProFile. K3, ProTaper and NRT instrument (n = 10 canals in each case). Pre- and post-operative images were recorded, and assessment of canal shape was completed with a computer image analysis program. The data were analyzed statistically using the One-way ANOVA followed by Duncan s test. The ability or instruments to remain centered in prepared canals at 1-, 2-mm levels was significantly better in ProFile groups than in other groups (p < 0.05). The change of centering ratio in NRT groups at 5-mm level was significantly greater than ProFile group and at 6- and 7-mm level than all other groups (p < 0.05). Although the NRT system was comparable to other systems in regards to its ability to maintain the canal configuration of apical portion, this system was more influenced by the mid-root curvature due to its stainless-steel files for coronal preflaring.

반복 하중 하에서 포스트의 종류에 따른 미세누출

정성호(Sung-Ho Jung),민경산(Kyung-San Min),장훈상(Hoon-Sang Chang),배지명(Ji-Myung Bae) 대한치과재료학회 2005 대한치과재료학회지 Vol.32 No.4

치근 절제술의 합병증으로 오인 가능한 재발성 구내 헤르페스

홍성옥(Sung-Ok Hong),이재관(Jae-Kwan Lee),장훈상(Hoon-Sang Chang) 대한턱관절교합학회 2013 구강회복응용과학지 Vol.29 No.4

두경부 악성종양에서 경부임파절전이에 대한 CT Scan의 진단적 의의

이원상(Won Sang Lee),김광문(Kwang Moon Kim),정광현(Kwang Hyun Chung),장훈상(Hoon Sang Chang),김지우(Jee Woo Kim),김동익(Dong Ik Kim) 대한두경부종양학회 1988 대한두경부 종양학회지 Vol.4 No.1

CT examination has been used in the preoperative examination of patients with head and neck cancer. The accuracy of CT in detecting nodal metastases has not been well established. We studied 35 patients (41 neck specimens) with head and neck cancer who underwent neck dissection. Surgical pathologic findings were compared with preoperative CT scan to establish the diagnostic accuracy for cervical lymph node metastases. The results of physical examination, CT scans of neck and histologic examinations were compared each other. The overall diagnostic accuracy of CT was 83.3%. Comparison with clinical accuracy shows the CT scan to be superior to the clinical examination in spite of careful physical examination, particularly in detecting occult metastases.

불소바니쉬 적용 후 심미수복재료의 색안정성 평가

장철훈(Chul-Hoon Jang),장동길(Dong-Gil Jang),이빈나(Bin-Na Lee),장훈상(Hoon-Sang Chang),황윤찬(Yun-Chan Hwang),오원만(Won-Mann Oh),황인남(In-Nam Hwang) 대한치과재료학회 2021 대한치과재료학회지 Vol.48 No.3

The objective of present study was to compare the color stability of esthetic materials after application of fluoride varnishes. Esthetic restorative materials including composite resin (Filtek Z350 XT, 3M ESPE, MN, USA), resin modified glass-ionomer (RMGI, Fuji II LC, GC Co., Tokyo, Japan), and giomer (Beautifil Flow Plus F00, Shofu Inc., Kyoto, Japan) were used in this study. Cavity shield (3M ESPE, MN, USA) and V-varnish premium (Vericom, Seoul, Korea) were used as the fluoride varnishes. 30 samples of each restorative materials were prepared, which were divided into 10 each, among three groups. Group I were stored in distilled water, which were used as the control, Group II were applied with Cavity shield and Group III were applied with V-varnish premium. All specimens were stored in the distilled water at 60 ℃ for 30 days for the accelerated test. Samples were then subjected to colorimetric analysis. Data collected was statistically analyzed using one way ANOVA and Tukeys post-hoc test (p=0.05). The color change before and after application of varnish was observed in all experimental groups. Especially RMGI showed highest ΔE * value (p<0.05). The color change according to the accelerated test showed no significant difference in the varnish application group and the control group. Giomer and RMGI applied with Cavity shield showed more color change than V-varnish applied group, despite no significant differences. Present study concludes that color stability of esthetic restoration materials can be affected by application of fluoride varnish. Especially, RMGI showed a large color change compared to the composite resin and giomer, which suggested that careful attention should be paid to clinical application.

Evaluation of the radiopacity and cytotoxicity of resinous root canal sealers

김창규,류현욱,장훈상,이병도,민경산,홍찬의,Kim, Chang-Kyu,Ryu, Hyun-Wook,Chang, Hoon-Sang,Lee, Byung-Do,Min, Kyung-San,Hong, Chan-Ui The Korean Academy of Conservative Dentistry 2007 Restorative Dentistry & Endodontics Vol.32 No.5

본 연구의 목적은 세 가지 레진계 근관충전실러 (AH 26, EZ fill, AD Seal), 산화아연 유지놀계 근관충전실러(ZOB Seal) 그리고 수산화칼슘계 근관충전실러 (Sealapex)의 방사선 불투과성 및 세포독성을 평가한 것이다. 각 실러를 제조회사의 지시대로 혼합하여 직경 10 mm, 두께 1 mm로 시편을 제작한 후 ISO 6876/2001의 규격에 따라 교합필름을 이용하여 알루미늄 스텝웨지와 함께 방사선 촬영을 시행하였다. 방사선 사진을 디지털화하여 컴퓨터에 저장한 후 Scion image 프로그램을 이용하여 각 단계의 알루미늄 스텝웨지의 두께와 비교하였다. 각 재료의 세포 독성은 불멸화된 인간 치주인대세포 (immortalized human periodontal ligament cell, IPDL)에서 MTT 분석법을 이용하여 시행하였다. EZ fill이 가장 높은 방사선 불투과성을 나타내었고 Sealapex가 가장 낮은 방사선 불투과성을 나타내었다 (p < 0.05). AH 26, AD Seal, ZOB Seal은 중등도의 방사선 불투과성을 나타내었다. Sealapex를 제외한 모든 평가된 재료는 ISO 규격에 부합하는 방사선 불투과성을 보였다. 레진계 실러의 세포독성은 모든 실험 시간대에 걸쳐 다른 계통의 실러에 비해 낮게 나타났다 (p < 0.05) 아울러, EZ fill은 24및 48시간대에서는 AD Seal에 비해, 72 시간대에서는 다른 두 레진계 실러에 비해 높은 세포독성을 보였다. 그러나 레진계 실러에서 방사선 불투과성의 정도와 세포독성과의 관련성은 없었다 (p > 0.05). 이 실험 결과로 볼 때 레진계 실러는 다른 계통의 실러에 비해 방사선 불투과성 면에서 장점을 가지며 생체적합성면에서 우수하다고 사료된다. The aim of this study was to evaluate the radiopacity and cytotoxicity of three resin-based (AH 26, EZ fill and AD Seal), a zinc oxide-eugenol-based (ZOB Seal), and a calcium hydroxide-based (Sealapex) root canal sealers. Specimens, 10 mm in diameter and 1 mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the Scion image software. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. The results demonstrated that EZ fill was the most radiopaque sealer, while Sealapex was the least radiopaque (p < 0.05). AH 26, AD Seal and ZOB Seal presented intermediate radiopacity values. All the materials evaluated, except for Sealapex, presented the minimum radiopacity required by ISO standards. The cell viabilities of resin-based root canal sealers were statistically higher than that of other type of root canal sealers through the all experimental time. Further, EZ fill showed statistically lower cell viability in 24 and 48 hours compared to AD Seal and in 72 hours compared to all other resin-based root canal sealers. However, there was no correlation between the radiopacity and cytotoxicity of three resin-based root canals sealers (p > 0.05). These results indicate that resin-based root canal sealer is more biocompatible and has advantage in terms of radiopacity.

Bonding efficacy of cured or uncured dentin adhesives in indirect resin

장지현,이빈나,장훈상,황윤찬,오원만,황인남,Jang, Ji-Hyun,Lee, Bin-Na,Chang, Hoon-Sang,Hwang, Yun-Chan,Oh, Won-Mann,Hwang, In-Nam The Korean Academy of Conservative Dentistry 2011 Restorative Dentistry & Endodontics Vol.36 No.6

연구목적: 본 연구는 간접 레진수복시 상아질 접착제의 중합 여부가 레진인레이와 상아질간의 미세인장결합강도와 결합계면의 형태에 미치는 영향을 공초점 현미경 관찰을 통하여 평가하고자 하였다. 연구 재료 및 방법: 24개의 발거된 대구치를 절단하여 교합면 상아질을 노출시켰다. 수복 방법에 따라 크게 간접 레진수복과 직접 레진수복의 두 군으로 나누었다. 간접 레진수복군은 임시 수복하여 1주일 후, 상아질 접착 과정에 따라 4군(OB-C와 OB-NC군, OS-C와 OS-NC군)으로 나누었다. 간접 레진수복군은 산부식 처리된 상아질면에 OptiBond FL (Kerr) 또는 One-Step (Bisco) 상아질 접착제를 중합 여부에 따라 나누어 적용하였다. 처리된 상아질면에 제작된 3 mm 높이의 레진 인레이(Tescera, Bisco)를 Variolink II (Ivoclar Vivadent)를 사용하여 제조사의 지시에 따라 합착하였다. 직접 레진수복군은 산부식 처리된 상아질면에 상아질 접착 후, 복합레진 (Estelite${\Sigma}$, Tokuyama)으로 즉시 수복하였다(OB-D군, OS-D군). 수복을 마친 모든 치아는 24시간 후, 미세인장 결합 강도 평가와 공초점 레이저 주사 현미경 관찰(CLSM)을 시행하였다. 결과: 간접 레진수복군은 직접 레진수복군에 비하여 낮은 미세인장결합강도를 나타내었으며, 상아질 접착제를 광중합한 군(OB-C군, OS-C군)이 광중합을 시행하지 않은 군(OB-NC군, OS-NC군)에 비하여 높은 미세인장결합강도를 나타내었다. 접착 계면에 대한 CLSM 관찰에서 상아질 접착제를 광중합한 군에서 더 분명하고 균일한 혼성층이 관찰되었다. 상아질 접착제를 광중합하지 않은 군에서는 혼성층이 불분명하거나 거의 관찰되지 않았다. 결론: 간접 레진수복물의 합착시 레진시멘트의 적용 전에 상아질 접착제의 광중합은 분명하고 균일한 혼성층의 형성하며, 이는 결합강도의 향상에 기여한다. Objectives: This study examined the effect of the uncured dentin adhesives on the bond interface between the resin inlay and dentin. Materials and Methods: Dentin surface was exposed in 24 extracted human molars and the teeth were assigned to indirect and direct resin restoration group. For indirect resin groups, exposed dentin surfaces were temporized with provisional resin. The provisional restoration was removed after 1 wk and the teeth were divided further into 4 groups which used dentin adhesives (OptiBond FL, Kerr; One-Step, Bisco) with or without light-curing, respectively (Group OB-C, OB-NC, OS-C and OS-NC). Pre-fabricated resin blocks were cemented on the entire surfaces with resin cement. For the direct resin restoration groups, the dentin surfaces were treated with dentin adhesives (Group OB-D and OS-D), followed by restoring composite resin. After 24 hr, the teeth were assigned to microtensile bond strength (${\mu}TBS$) and confocal laser scanning microscopy (CLSM), respectively. Results: The indirect resin restoration groups showed a lower ${\mu}TBS$ than the direct resin restoration groups. The ${\mu}TBS$ values of the light cured dentin adhesive groups were higher than those of the uncured dentin adhesive groups (p < 0.05). CLSM analysis of the light cured dentin adhesive groups revealed definite and homogenous hybrid layers. However, the uncured dentin adhesive groups showed uncertain or even no hybrid layer. Conclusions: Light-curing of the dentin adhesive prior to the application of the cementing material in luting a resin inlay to dentin resulted in definite, homogenous hybrid layer formation, which may improve the bond strength.

Effects of various root canal sealers on tooth discoloration and internal bleaching

Yi-San Kim(김이산),Sung-Hyeon Choi(최성현),Kyeong-Eun Youn(윤경은),Ji-Hyun Jang(장지현),Hoon-Sang Chang(장훈상),Yun-Chan Hwang(황윤찬),In-Nam Hwang(황인남),Won-Mann Oh(오원만),Bin-Na Lee(이빈나) 대한치과재료학회 2019 대한치과재료학회지 Vol.46 No.1

There are several causes of tooth discoloration following root canal treatment. In this study, we evaluated the effects of sealers on tooth discoloration and internal bleaching. Twenty-four teeth were divided into 4 groups: control group, AH plus, Endosequece BC, and MTA fillapex group. Root canal filling was performed using each sealer conventionally and non-vital bleaching was performed with sodium perborate. The L, a, and b values were measured using Vita easyshade. Tooth discoloration after root canal treatment occurs irrespective of the type of sealers and may cause discoloration with only gutta-percha cone. The effect of non-vital bleaching following the use of calcium silicate-based sealers such as Endosequece BC and MTA fillapex was higher than that of AH plus. Therefore, it needs careful use of sealers in endodontics and calcium silicate-based sealers have advantages of bleaching in case of discolored tooth.