• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.290-296
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• 2018

Purpose: The aim of this study was to evaluate the polymerization ability of resin-based materials used for teeth splinting according to the thickness of cure. Materials and Methods: For this study, the Light-Fix and G-FIX developed for resinous splinting materials and the G-aenial Universal Flo, the high-flowable composite resin available as restorative and splinting material, were used. Ten specimens of the thickness of 2, 3, 4 and 5 mm and 5 mm in diameter for each composite resin (total 120) were prepared. The microhardness of top and bottom surfaces for each specimen was measured by the Vickers hardness testing machine. The polymerization ability of the composite resin for each thickness was statistically analyzed using independent T-test at a 0.05 level of significance. Results: There was no difference of polymerization ability regardless of the thickness in the Light-Fix and G-FIX. The G-aenial Universal Flo showed significantly low polymerization ability from the thickness of the 3 mm (P < 0.05). Conclusion: The Light-Fix and G-FIX, which are resin-based materials used for teeth splinting, are expected to be suitable for light curing up to 5 mm in thickness.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.209-216
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• 2021

Purpose: The purpose of this study is to compare the shear bond strength of resin cement for orthodontic brackets without applying an adhesive primer, to the case of applying an adhesive primer. Materials and Methods: The specimens were divided into three experimental groups, Transbond XT, GC Ortho Connect and Orthomite LC, and the enamel surface was divided into two sections, one with 37% phosphoric acid and the other with 37% phosphoric acid and an adhesive primer or universal adhesive. Each of three types of cement was applied to orthodontic bracket, and after bonding, the shear bond strength was measured. Results: Transbond XT and Orthomite LC significantly increased shear bond strength when orthodontic brackets were bonded after applying an adhesive primer and universal adhesive, respectively. Conclusion: It is expected that application of an adhesive primer or universal adhesive after acid etching will improve shear bond strength of orthodontic brackets in Transbond XT and Orthomite LC.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.2
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• pp.81-89
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• 2022

Purpose: Wireless endodontic handpieces (WEH) are widely used in dental clinics due to their convenience and portability. This study aimed to compare the vibration magnitudes and patterns generated by five WEH. Materials and Methods: Vibration acceleration of five WEH (X-Smart IQ, E connect S, Endo A Class, ENDOIT, and TRAUS ENDO) in the rotary and reciprocating motion was measured with accelerometer The average vibration acceleration was analyzed using the t-test, Welch's ANOVA test, and Dunnett T3 test at P < 0.05. Results: In all WEH, the average vibration acceleration in reciprocating motion was significantly higher than that in rotary motion (P < 0.001). In rotary motion, repeated vibration graphs of constant amplitude were obtained without sudden changes in the magnitude of vibration, and the average vibration acceleration value was high in the order of X Smart IQ, Endo A Class, ENDOIT, E Connect S, and TRAUS ENDO (P < 0.001), there was no statistically significant difference between X Smart IQ and Endo A Class. In reciprocating motion, a vibration graph was obtained in which large amplitude peaks appear at specific points within one cycle are repeated. The average vibration acceleration value was highest in the order of X Smart IQ, E Connect S, Endo A class, ENDOIT, and TRAUS ENDO (P < 0.001). Conclusion: Regardless of the type of WEH, greater vibration occurred in the reciprocating motion than in the rotary motion (P < 0.001). In the reciprocating motion, there was a difference in vibration for all handpieces (P < 0.001).

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.1
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• pp.1-12
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• 2024

Purpose: To histologically evaluate the effects of three calcium silicate-based sealers on rat mandible tissue. Materials and Methods: Rats were randomly divided as follows: A group that sacrificed immediately after cavity preparation, a group that sacrificed two weeks after cavity preparation, a group that sacrificed two weeks after CeraSeal (CS), AH Plus Bioceramic (AHB), or One-Fil (OF) sealer injection, respectively. After tissue processing for all groups, the bone tissue area (%) and the number of osteoclasts in and around the cavity were measured under a microscope. The results of each group were compared and statistical analysis was performed using one-way ANOVA and Tukey's test. Results: The formation of bone tissue and the presence of osteoclasts in the cavity were observed in the group that sacrificed two weeks after cavity preparation and the group sacrificed two weeks after AHB sealer injection, and these groups showed significantly higher average bone tissue area (%) than the other groups. In the other groups, no inflammation or foreign body reaction occurred in the cavity, and no osteoclasts were observed. Conclusion: All calcium silicate-based sealers used in this study showed a favorable bone tissue response when injected into the rat mandible. In particular, higher bone formation in the cavity was observed in AHB.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.1
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• pp.31-38
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• 2024

Dens in dente is a developmental anomaly resulting from infolding of the enamel organ into dental papilla prior to calcification of dental tissue. The pulpal tissue of the tooth can be vulnerable for bacterial invasion through direct exposure to the oral cavity or through defective enamel and dentin of the infolding part, thereby increasing the possibility of pulpal necrosis and subsequent apical periodontitis. Treatment planning of teeth with dens invaginatus may be difficult due to the complex root canal morphology. Therefore, thorough knowledge of anatomical variations of dens invaginatus is of great importance for proper treatment planning. The focus of this case report is on Oehler's type II and III dens invaginatus. The infolding of type III dens invaginatus extends beyond the crown and CEJ. Bacterial invasion through the infolding can easily cause inflammation of the pulpal and periradicular tissue. This case report presents endodontic treatment of type II and III dens invaginatus with the aid of CBCT.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.142-149
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• 2002

Purpose : The purpose of this study is to compare with result of repair and resection in displaced bucket handle medial meniscal tear. Materials and Methods : From Sep. 1998 to Dec. 2001, we experienced 46 cases, 45 patients. We classified them into repair group (group I, 23 cases) and resection group (group II, 23 cases). We analyzed the time interval between injury and operation, zone of tear, the status of reduction and quality of displaced fragment of all cases. Average follow-up period is 29, 28 months, respectively. We evaluated the final results of both groups as Lysholm knee score, radiologic changes and 2nd look arthroscopy. Results : Mean age was 25 years old in both group, respectively. Mean interval between injury and surgical treatment was 12 and 17 weeks. respectively. In group I, 6 of 7 cases were evaluated as clinical success in red-red zone, 12 of 15 cases were assessed as clinical success in red-white zonal tear, stable reduction. Another case which is evaluated as clinical failure showed red-white zonal tear, unstable reduction and poor quality meniscal fragment. 5 cases showed variant degrees of tibio-femoral compartment symptom. In group II, red-white zone (9 cases) and white-white zone (14 cases) were treated as resection and got good results. Conclusion : Considering zone of tear, reducibility and quality of meniscal fragment before treatment will improve the success rate of meniscal repair.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.150-156
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• 2021

Purpose: To determine how the location, displacement, intra-articular involvement, comminution of a 5th metatarsal base fracture affect results of early weight-bearing treatment. Materials and Methods: From January 2013 to July 2017, 34 cases of 34 patients diagnosed with a fracture of the zone I and II 5th metatarsal base were enrolled. The mean follow-up period was 13 months (6-15 months). One patient was excluded as a refracture during the follow-up period, and 33 patients underwent conservative treatment. Anteroposterior, lateral, and simple oblique radiography and computed tomography of the foot were performed to evaluate the location and displacement of the fracture, the degree of joint involvement, and comminution. In all 33 patients, a short leg cast or boot brace was selected immediately after the injury, tolerable weight bearing was allowed. If the pain disappeared, full weight bearing was performed after wearing a plain shoe or postoperative shoe. As a clinical result, the American Orthopedic Foot and Ankle Society (AOFAS) score was evaluated at the final follow-up. During outpatient follow-up, a simple radiograph of the foot was taken to confirm the time of radiological bone union and return to work. Results: Nine males and 24 females, with an average age of 48.7 years, were enrolled in the study. Twenty-four patients had zone I fractures, and nine patients had zone II fractures. Twenty-two out of 33 patients had a fracture displacement of 2 mm or more. Nine and five patients had joint involvement and comminution, respectively. There was a statistically significant return to work from zone I to zone II. The AOFAS score was excellent at the final follow-up and there was no significant difference. When classifying and comparing the degree of fracture displacement, joint involvement, and comminution, there were no significant differences in the radiological union time and return to work. In all cases, satisfactory results were obtained at the final follow-up. Conclusion: Satisfactory clinical results can be obtained by allowing early weight-bearing regardless of the fracture location, displacement, joint involvement, or comminution in zone I and II 5th metatarsal base fractures.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.77-82
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• 2006

Purpose: The purpose of this study was to analyze the clinical results of symptomatic lateral discoid meniscus found in adults over 40 years old. Materials & Methods: From March 1994 to March 2004, 53 cases treated for lateral discoid meniscus in 48 patients aged over 40 years with the mean age $48.4(40{\sim}62)$ who were followed up more than 1 year, were analyzed by physical findings, simple X-ray, MRI and arthroscopic exam. Results: Most of the cases (42 cases, 79.2%) had symptoms for less than 1 year duration. 26 cases(49.1 %) out of 53 had trauma history. Simple radiologic evaluation showed that lateral condylar abnormality such as the flattening of lateral femoral condyle, marginal osteophytes, and subchondral sclerosis was seen in 37cases(69.8%). Also medial condyle showed degenerative changes in 16 cases (30.2%). Tear of discoid meniscus in 45 cases(84.9%) were examined by arthroscope and tear was not detected in 8 cases(15.1%). Type of tear was complex(18 cases), longitudinal(12 cases), horizontal(11 cases) and transverse(4 cases). Concomitant medial meniscal rupture was found in 7 cases(13.2%). The simple procedure done was reshaping(46 cases), subtotal resection(5 cases), total resection(1 case) and meniscal repair after reshaping in 6 cases, and arthroplasty was performed after arthroscopic examination in 1 case. Conclusion: Onset of symptom in adult lateral discoid meniscus is usually traumatic in origin. Most cases showed radiologic abnormality such as degenerative change in lateral condyles as well as medial condyles and the results of preservative surgical treatment was the most preferred option in most patients.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.199-206
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• 1993

본 연구는 1987년 1월부터 1991년 12월까지 연세대학교치과병원 구강악안면외과에 과두 골절이 의심되어 내원한 환자중 임상 및 방사선학적 소견에서 하악과두 골절로 진단되어 비외과적 치료를 받은 12세 미만의 13명의 소아환자를 연구 대상으로 하여 임상 및 방사선학적 소견을 분석하여 다음과 같은 결론을 얻었다. 비외과적인 보존적 또는 기능적 치료를 받은 후의 결과는 양호하였으며, 골의 재생과 개조는 신속하여 골 구조는 기능 중에 가해진 힘에 반응한다는 Wolff의 법칙과 일치하는 듯이 보였다. 두 예의 골절탈구에서 과두의 단축 및 과두가 골절된 악관절에서 clicking음을 보였으나 저작하거나 개구시에 큰 어려움은 없었다. 술후 관찰기간이 불충분하였으나 본 예의 대부분에서 비외과적인 술식에도 만족스러운 치료결과를 보였다.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.441-452
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• 2012

Most of signs and symptoms of temporomandibular disorder(TMD) is temporary and self-limiting as other musculoskeletal diseases. Conservative, reversible treatment; self care, behavior modification, physical therapy, pharmacotherapy, splint therapy should be considered as initial treatment for temporomandibular disorder rather than non conservative, irreversible treatment.