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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
Journal Basic Information
Journal DOI :
Korean Academy of Pediatric Dentistry
Editor in Chief :
Volume & Issues
Volume 28, Issue 4 - Nov 2001
Volume 28, Issue 3 - Aug 2001
Volume 28, Issue 2 - May 2001
Volume 28, Issue 1 - Feb 2001
Selecting the target year
ORTHODONTIC TREATMENT THROUGH EXTRACT10N OF UPPER AND LOWER LATERAL TEETH
Park, Sang-Hyun ; Lee, Kwang-Hee ; Kim, Dae-Eop ; Lee, Jong-Seon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 547~552
Extracting mandibular incisors for orthodontic treatment may adversely affect the occlusion. However, when properly used, extraction of mandibular inciors is a selection for the correction of the malocclusion. Generally, treatment for crowding needs to select between nonextraction and four premolar extraction. Approaches for crowded mandibular incisors include distal movement of posterior teeth, lateral movement of canines, labial movement of incisors, interproximal enamel reduction, removal of premolars, removal of one or two incisors, and various combinations of the above. Extraction of incisors is used in case of crowding, anterior tooth size discrepancy, absent of maxillary lateral incisors, and ectopic eruption. But severe overjet. overbite, and space are the contraindication of it. A patient had severe crowding on upper anterior teeth, impacted upper left lateral incisor, palatal ectopic eruption of upper right incisor and severe crowding on lower anterior teeth. Lower lateral incisors are extracted for space availability and facial esthetics. We report the case of orthodontic treatment of upper and lower anterior crowding through extraction of lateral incisor.
THE STUDY ON SHEAR BOND STRENGTHS OF VARIOUS ONE-BOTTLE DENTIN ADHESIVES
Oh, So-Hee ; Kim, Jong-Soo ; Kwon, Soon-Won ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 553~565
One-bottle adhesive system was recently developed in order to simplify the clinical skills and save chair time after continuous improvements on dentin bonding agents. To test the shear bond strength of a new "one-bottle adhesive" system to bovine dentin various commercially available one-bottle adhesives(Prime & Bond
, One Coat
) were included for comparison. And we observe the interfacial morphology by scanning electron microscope. The results were as follows; 1. Group II (One Coat
) showed higher shear bond strength than group I (Prime & Bond
), group III(Syntac
), and group IV(Single
), but no statistically significant difference was founded between groups(p>.05). 2. Relating reverse-cone shape resin tags were observed in samples of all groups under SEM. We could observed hybrid layer, resin tag and many lateral branches in every group. But, we observed in group III rare lateral branched than other three groups, and discontinuous hybrid layer.
A STUDY ON THE EFFECT OF SALIVA CONTAMINATION ON THE BOND STRENGTH OF ONE-BOTTLE ADHESIVE SYSTEM
Jeon, Hyung-Joon ; Kim, Jong-Soo ; Kwon, Soon-Won ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 566~574
For decades it has been a clinically accepted requirement, in case of salivary contamination, to re-etch conditioned enamel and dentin to proceed with the adhesive technique. Only a few reports have been so far dealing with the potential of one-bottle adhesive system to bond even when applied after salivary contamination and without re-etching. The purpose of this study was to evaluate the influence of the salivary contamination on the shear bond strength of dentin. The results were as follows: 1. In group II, in which saliva contamination and washing occurred before applying of Prime & Bond NT showed high shear bond strength as in control group. In Group III and IV, in which the cured adhesive was contaminated with saliva, showed significantly lower mean bond strength, 2. Relating long resin tags of
were observed in samples of all groups under SEM. We could observed hybrid layer, resin tag and many lateral branches in every group. And there were no differences between groups.
TREATMENT OF ANTERIOR TEETH FRACTURE BY FORCED ERUPTION
Kim, Ji-Young ; Choi, Nam-Ki ; Yang, Kyu-Ho ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 575~582
There have been many treatment methods for traumatic subgingival crown fracture and intrusion without spontaneous eruption. The orthodontic forced eruption generally results in favorable clinical findings than crown lengthening with osteotomy and intentional replantation. In first two cases with subgingival crown fracture due to trauma, authors applied orthodontic forced eruption with axed appliance after root canal therapy and then restored them with composite resin. In another case with traumatic intrusive luxation, we observed spontaneous eruption of the corresponding tooth for about 6 months and then returning it to normal position by forced eruption with removable appliance, but root canal filling was conducted after apexification due to devitalization during forced eruption, and so clinically favorable results were obtained.
INHIBITORY EFFECT OF LACTOCOCCUS LACTIS 1370 ON THE FORMATION OF DENTAL PLAQUE IN CHILDREN
Lee, Lan-Young ; Lee, Chang-Seop ; Lee, Kwang-Hee ; Oh, Jong-Suk ; Lee, Sang-Ho ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 583~592
This study was undertaken to evaluate the clinical effect of inhibiting plaque formation of Lactococcus lactis 1370, a acid producing bacterium residing in the mouth. 30 children were asked to use 10ml of control mouth-wash and mouthwash containing Lactococcus lactis 1370. The plaque index and plaque area rate at 24h and 48h after the use of the mouthwashes were measured. And the number of Lactococcus lactis 1370 was counted at 1h, 3h, and 6h in the mouth. The results are as follow. 1. The mean plaque index at 24h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 2.43 and 2.06, respectively. The inhibiting rate of plaque formation was 15% (P<0.05). 2. The mean plaque index at 48h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 2.95 and 2.17, respectively. The inhibiting rate of plaque formation was 26%, showing more decrease than at 24h(P<0.05). 3. The mean plaque area rate at 24h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 21.2% and 15.6%, respectively. The inhibiting rate of plaque formation was 26% (P<0.05). 4. The mean plaque area rate at 48h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 33.0% and 17.8%, respectively. The inhibiting rate of plaque formation was 46% (P<0.05). 5. The number of Lactococcus lactis 1370 in the mouth decreased significantly from mouthwashing to 3h, but increased slightly between 3h and 6h. As seen with the above results, we think that using the mouth wash with Lactococcus lactis 1370 would prevent the formation of plaque in the mouth and can be an effective method to prevent dental caries and periodontal disease.
A STUDY OF THE MAXIMUM MOUTH OPENING IN CHILDREN
Baik, Byeong-Ju ; Kim, Sang-Hoon ; Yang, Yeon-Mi ; Kim, Jae-Gon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 593~599
Recently, tempormandibular disorder(TMD) shows an tendency to increase every year. TMD is a collective term embracing a number of clinical problems that involve the masticatory musculature, temporomandibular joint(TMJ) and associated structures, or both. TMD, viewed in distribution of age, often occurred from late teens to late twenties. But recently, the age of occurrence tends to be lower. Accordingly, early diagnosis of tempormandibular disorder is very important. In this study, we measured the maximum mouth opening which is simple and easy to carry out as a way of TMD diagnosis. In this study, the maximum mouth opening was examined for 1,775 children from 4 to 12 years of age. We compared the relationship between the maximum mouth opening with the age, height, and weight. The results obtained were summarized as follows; 1. The mean maximum mouth openings of 4, 8, and 12 year of age were respectively 40.16mm, 47.32mm, 50.54mm for male, 39.79mm, 44.85mm, 48.09mm for female. 2. The maximum mouth opening increased with age, and the values were greater in male than in female. 3. The maximum mouth opening increased with height, and the values were eater in male than in female except between 105cm and 115cm 4. The maximum mouth opening increased with weight, and the values were eater in male than in female. 5. The correlation between the maximum mouth opening with the age, height, and weight was all significant, and height showed the highest correlation.
AN INVESTIGATION OF TRAUMATIC DENTAL INJURIES IN CHILDREN
Baik, Byeong-Ju ; Yang, Yeon-Mi ; Yang, Cheol-Hee ; Kim, Jae-Gon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 600~612
The purpose of this study is concerned with an investigation of the actual condition of traumatic injuries of teeth and supporting structures in children to set up possible criteria for prevention and treatment of injured teeth. The materials consisted of the clinical records of 431 traumatically injured teeth of 212 children, accumulated during two years from the first of April in 1998 to the end of March in 2000, supplied from the Dept. of Pediatric Dentistry, Chonbuk National University Hospital. The incidence of injuries in boys was extremely high for permanent teeth, twice as high as in girls. Accidents to primary teeth were most common from 1 to 2 years of age and to permanent teeth were most from 8 to 9 years of age. The most common cause of trauma was a fall for both primary and permanent teeth, followed by collision. The anterior teeth in maxilla was most frequently affected by trauma in both the primary and permanent teeth. The most common type of trauma were loosening for the primary teeth, followed by luxation types which included the intrusion, displacement and extrusion and complete avulsion types. For the permanent teeth, the most common type of trauma were tooth fracture. The most common trauma of soft tissue was laceration of upper lip, lower lip and gingiva of maxilla Concerning treatment at the first visit, primary teeth with only loosening and concussion were not usually treated. Permanent teeth were often treated by crown restorations for crown fractures and by endodontic procedures for pulpal exposure. Though we could elucidate actual condition of traumatic injuries of teeth in children, we should make a follow-up survey to ensure the prognosis of injured teeth and establish the most desirable criteria for traumatized teeth in children.
IN VITRO COMPARISON OF VARIOUS DIAGNOSTIC METHODS OF OCCLUSAL CAR10US LESIONS
Kim, Jae-Gon ; Kim, Young-Jin ; Kim, Young-Sin ; Baik, Byeong-Ju ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 613~619
The aims of this study were to compare the accuracy, sensitivity and specificity of cnventional visual examination, radiography and a new laser fluorescence method, KaVo Diagnodent, for the detection of occlusal caries lesions. One hundred sound human premolars and molars which had no restorations or interproximal cavities were tested by three methods. Tooth lesions depth was assessed at histologic examination using Caries detector dye The following results were obtained. 1. Diagnodent show 7.8 in sound tooth, 25.4 in initial caries, 30.5 in enamel caries, and 53.8 in dentin caries with average score 2. Spearman and Pearson relation coefficient was high between tooth-specimen test with dye and Diagnodent(0.736, 0.619), visual examination(0.664, 0.666), and was low between tooth-specimen test with dye and radiographic examination(P<0.01, total) 3. Accuracy of occlusal caries was highest on Diagnodent(65%) and lowest on radiographic examination(35%) 4. In initial caries, the sensitivity and specificity of Diagnodent method was the highest. In enamel caries, the sensitivity of visual examination was the highest and specificity of Diagnodent method was the highest. In dentinal caries, the sensitivity and specificity of Diagnodent method was the highest and sensitivity of visual examination was the lowest.
ROOT CANAL TREATMENT ON PRIMARY TEETH USING NICKEL-TITANIUM NOTARY FILES
Seo, Ju-Hee ; Lee, Kwang-Hee ; Kim, Dae-Eop ; Yang, Kye-Sik ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 620~625
The pulpectomy or root canal treatment on primary teeth is to be done when there is evidence of chronic in flammation or necrosis in the radicular pulp. Due to the tortuous and ribbon-shaped anatomy of the primary teeth, the instrumentation of endodontic hand files and barbed broaches is not an easy procedure. Recently, many automatic Ni-Ti rotary instruments have been developed and has made endodontic treatment easier and faster. This report describes two cases of root canal treatment on primary molars using Ni-Ti rotary files. The cervical constricture was eliminated by the crown-down method, as smaller file proceeded unhindered into the apical third of the canal. In addition, the crown-down technique enhanced the efficacy of the endodontic irrigant. The use of rotary instrumentation for primary teeth seemed to be a more effective way to debride the uneven walls of primary teeth.
USE OF MAGNETS IN THE TREATMENT OF ECTODERMAL DYSPLASIA
Ju, Jin-Hyung ; Lee, Kwang-Hee ; Kim, Dae-Eop ; Lee, Jong-Seon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 626~632
Ectodermal dysplasia is a hereditary disease characterized by congenital dysplasia of one or more ectodermal structures. Intraorally, common findings are anodontia or oligodontia, conical teeth, and, consequently, generalized spacing. This case presented the oral rehabilitation of a child with hypohidrotic ectodermal dysplasia. Oral rehabilitation is important from functional, esthetic, and psychologic perspectives. Due to the absence of teeth, the volume of alveolar bone and its growth are decreased, resulting in a loss of vertical dimension and protuberant lips. The treatment involved increasing the patient's vertical dimension of occlusion, fabricating a maxillary partial denture, and using magnets to help retain the mandibular partial denture. A 5-year 7-month old Korean boy was referred to the pediatric department for examination, evaluation and treatment of his disorder. we used magnets on '73 and '83 for enhanced retention of a mandibular overdenture. The magnet used in this case was the Magfit system(GC Co., Japan).
LOCAL ANESTHESIA IN CHILDREN USING JET INJECTION INSTRUMENT
Lee, Jae-Chun ; Kim, Dae-Eop ; Lee, Kwang-Hee ; Kim, Seong-Hyeong ; Yang, Kye-Sik ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 633~637
Local anesthesia procedure in pediatric dentistry using needle-tipped syringes is stressful and painful for the child patients The Syrijet Mark II (Mizzy Inc. USA) is a jet injection instrument, which uses high pressure to propel fluids into soft tissue without the use of a hollow neeldle, so it seems to be able to reduce the injection phobia of the child patients. The authors compared the Syrijet with the conventional syringe by assessing the pain level after local anesthetic procedures using CAS(color analogue scale) which was developed from VAS(visual analogue scale). The result showed that the pain was reduced by the use of syrijet. The advantages of syrijet were no use of neeldes, the reuse of the anesthetic cartridge, and the safety to nerves and vessels. The disadvantages were the large size, the high price, and the need of skill to use.
A STUDY ON THE SHEAR BOND STRENGTH BY PLASMA ARC CURING SYSTEM FOR BRACKET BONDING
Kim, Jung-Yoon ; Kim, Jong-Soo ; Kwon, Soon-Won ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 638~642
Recently, plasma arc curing system for curing resin composites has been introduced. This is characterized by a high output of light energy, which has the advantage of reducing the chair time and thereby making the treatment more comportable for the patients as well as for the dentist. The purpose of this study was to compare the shear bond strengths of light-cured orthodontic adhesive polymerized with conventional halogen light and plasma arc light. The 2 curing devices used were the XL3000 (3M, USA) conventional curing light and the Flipo (LOKKI, France) plasma arc light. The results from the present study can be summarized as fellows; 1. The mean shear bond strength for three groups were quite similar for 50 second conventional light group, 2 second plasma arc curing light group, 5 second plasma arc curing light group. 2. There was no statistically significant difference for three groups(p>0.05).
FACE MASK THERAPY IN EARLY MIXED DENTION
Lee, Chang-Joo ; Kim, Jong-Soo ; Kwon, Soon-Won ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 643~648
Class III malocclusion usually becomes manifested at a very early age, most typically evidenced clinically by the appearance of either an edge-to-edge incisor relationship or an anterior crossbite. Anterior crossbite, by it-self, retards growth of maxilla, and accelerates growth of mandible. So, treatment should be started as early as the patient cooperates, removing any factors or forces that inhibit growth and development in the same physiologic maxillary displacement direction. The facial mask is effective in most developing Class III patients, because the appliance system affects virtually all areas contributing to a Class III malocclusion. Thus, the facial mask can be applied to most developing Class If cases regardless of the specific etiology. In these cases, the results were followed. Anterior crossbite was corrected by anterior movement of maxilla and downward backward rotation of mandible and simultaneously, lower facial height was increased. So, it can be concluded that the facial mask is effective in treating growing patients with a deficient maxilla.
MAXILLARY FLOATING TEETH IN A CHIARI MALFORMATION PATIENT
Shin, Eun-Young ; Choi, Byung-Jai ; Lee, Jae-Ho ; Son, Heung-Kyu ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 649~653
The Chiari malformation is a deformation within the central nervous system which the lower brain stem and the cerebellum migrate into the foramen magnum causing herniation. In 1891, Arnold Chiari classified such symptoms into 3 categories. This case report is of a 8-year-old female with the complaint of a slight facial swelling and pain on the upper right molar during tooth brushing since 10 days before. Clinical examination showed gingival pocket formation on distal of the upper right first molar with pain and mobility of the tooth. Radiographic examination showed generalized low bone density in the upper molar area, and especially no bone support above the upper right and left first molars were noted. With a temporary diagnosis of Early-onset periodontitis, consultations with medical doctors for the possibility of an underlying systemic disease were made during periodontal treatment. 3D CT was taken with after a final diagnosis of Chiari malformation. Generalized thinning and defect of the cranial bone was noted and the foramen magnum was slightly enlarged. The occipital and maxillary bone was low in density, and the alveolar bone of maxillary posterior teeth was especially almost non-existing causing the upper right and left first molar to be floating. For this, the patient went under consultation with the department of neurosurgery and is still under observation. Periodontitis in childreren is very rare. When symptoms of periodontitis appear in a child, due to the possibility of an underlying systemic disease such as leukemia, histiocytosis X, and hypophosphatasia, proper examinations should be carried out so that the primary factor the symptoms can be treated.
TYPE II DENTINOGENESIS IMPERFECTA : CASE REPORT
Kim, Chi-Hyun ; Lee, Jae-Ho ; Choi, Byung-Jai ; Lee, Chong-Gap ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 654~660
Dentinogenesis imperfecta is an example of an inheritable dentinal defect originating during the histodifferentiation stage of tooth development, with involvement of the primary and permanent teeth. Shields, Bixler and El-Kafrawy proposed three types of Dentinogenesis imperfecta : Type I, II, III. Witkop reported a prevalence of 1 in 8000 with the trait, and no significant difference between male and female. Affected teeth have red-brown discoloration often with distinctive wearness of occlusal surface of posterior teeth and incisal surface of anterior teeth. Once enamel seperated from underlying defective dentin, the dentin demonstrates significantly acclerated attrision. Radiographically, the teeth have thin roots, bulbous crown, cervical constriction, and obliteration of the root canals and pulp chambers. In primary dentition periapical lesions or multiple root fractures are often observed. In successive generations the phenotypes of discoloration and wearness of teeth occurred, and one of the patient's subships, 10 year-old sister, showed general discoloration of her teeth and mild wearness. In this case, a 4 year-old male reported to the Yonsei University Pedodontics clinic, with a chief complaint of discolored teeth. The teeth showed generally yellowish-brown discoloration and moderate wearness. In radiographic features, obliteration of pulp, bulbous crown, and short roots were observed. It was diagnosed as Dentinogenesis imperfecta. The posterior teeth were restored with Stainless Steel Crown, and defective incisors including left upper primary central incisor which was extracted due to a root fracture with Open-faced Stainless Steel crown.
THE TYPES AND CONTENTS OF SWEETENERS IN LIQUID ORAL MEDICINES
Hwang, Min-Sung ; Kim, Jung-Wook ; Lee, Sang-Hoon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 661~667
Though a consensus seems to exist about the regulation of the use of sugar-containing food, however. an unrecognized and significant supply of cariogenic carbohydrate remains in the form of sugar-containing liquid oral medicine to prevent dental caries. children who are taking long-term sugar-containing liquid medicine have an increased risk of developing dental caries. The aim of this study is to get the information about the sugars in liquid medicines prescribed for the children. To get the information, the number and date of all prescriptions of liquid medicines for one month at pediatric hospital of Seoul National University Hospital were investigated. From that data, the most frequently used pediatric oral liquid medicine is presented. Then, for the information of the type and contents of sweeteners in that preferred medicines, the manufacturers of each medicines were asked for the data of sugar types and contents, and the informations about the medicine contents were collected via facsimile. The most frequently used pediatric oral liquid medicine were followed as expectorant, purge, antibiotic, drug for iron deficiency anemia, sedative, antihistamine, anticonvulsant, NSAIDs in order. The mean value of sweetener content in liquid medicines was
and most frequently used sweetener is sucrose.
INTERRATER RELIABILITY OF CARIES DIAGNOSIS BY LASER FLUORESCENCE
Lee, Kwang-Hee ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 668~672
The purpose of study was to measure the interrater reliability of the caries diagnostic instrument, Diagnodent(KaVo, Germany), using a new laser fluorescence technique. Occlusal surfaces and smooth surfaces of one hundred extracted human premolars and molars were examined by four dentists. Pearson correlation coeffcients were 0703 to 0.870 for occlusal surfaces and 0.764 to 0.932 for smooth surfaces (P<0.01, all). Reliability coefficients which were calculated by intraclass correlation coefficients were 0.9450 for occlusal surfaces and 0.9605 for smooth surfaces. Therefore, the interrater reliability of caries diagnosis by Diagnodent is very high, and the rater training would be necessary more for occlusal surfaces than for smooth surfaces.
HYDROLYTIC DEGRADATION OF POSTERIOR RESIN RESTORATIVE MATERIALS
Yang, Kuy-Ho ; Park, Mi-Ran ; Choi, Nam-Ki ; Park, Eun-Hae ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 673~682
The use of resin composites has continued to increase over the last several years. In spite of their growing popularity, composites continue to exhibit a number of undesirable characteristics. One of the major deficiencies of composite restorative resins is their inadequate resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. This solution with a high concentration of hydroxyl ions is a convenient medium for accelerated degradation of silane coupling and filler particles. The brands studies were Definite(
AG, Germany), Prodigy(Kerr, USA), Pyramid(Bisco, USA) and Synergy(Coltene, Swiss). Preweighed discs of each brand were exposed to 0.1N NaOH solution at
. After 14 days they were removed, neutralized with HCl, washed with water and dried. Resistance to degradation was evaluated on the basis of following parameters : (a) mass loss(%)-determined from pre-and post-exposed specimen weights : (b) Si loss(ppm)-obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation
-measured microscopically (SEM) from polished circular sections of exposed specimens. The results were follows: 1. Mass loss of Synergy was
, it was the highest, there was no significant difference among the materials. 2. The degree of degradation layer depth of Synergy was
, it was the highest, there was no significant difference among any other materials than Synergy. 3. There was no difference among the four materials in Si loss. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.06, p<0.05). 5. There was no coefficient correlation between Si loss and mass loss, the degree of degradation layer depth and Si loss. 6. When observed with SEM, destruction of bonding is observed between resin matrix and filler.
EFFECTS OF ER:YAG LASER ABLATION ON THE DENTIN
Choi, Nam-Ki ; Yang, Kyu-Ho ; Park, Sang-Won ; Kim, Ok-Joon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 683~693
The purpose of this study was to evaluate the effects of Er:YAG laser on cutting efficacy and its histologic findings. Dentin specimens of human premolars and molars were used and irradiated by Er:YAG laser with noncontact handpiece type delivery system under different treatment condition of irradiation time. Cavity pattern and volume were evaluated to determine the cutting efficacy and following results were obtained. 1. Cutting volume of sound dentin was getting larger with time immersed in water increase 2. With the condition of irradiation (150mJ, 10Hz, 30sec), surface irregularity was more increased in sound dentin comparing to carious dentin. For the light microscopic examination, dentinal tubules were opened and ash flecks and cracks were noted with inconsistence of dentinal tubules. 3. In case of 30 sec. irradiation in carious dentin, dark zone was limited to small focus whereas 1 min. irradiation, more wider, and cracks were noted in the perpendicular to direction of dentinal tubules. For the 2 min. irradiation, cavity was the widest and more cracks were found.
INVERTED LABIAL BOW APPLIANCE FOR ANTERIOR CROSSBITE CORRECTION : REPORT OF A CASE
Park, Jin-A ; Park, Ho-Won ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 694~699
The prognosis for class III patients in growing child can be made in mixed dentition and the severity of the symptom is often amenable to early intervention. Class III malocclusion can be classified as functional class lit and skeletal origin. Skeletal Class III malocclusion is usually characterized by overdeveloped mandible, underdeveloped maxilla, but the cause of pseudo class III is most dentoalveolar or functional shift of mandible. The primary goal of early intervention of malocclusion is to supply an environment that is conducive to the development of favorable occlusal relationships and avoiding of worsening of the problems. Inverted labial bow appliance is introduced as an appliance to combine the advantage of active plate and activator. It is undemanding with this appliance to initiate not only dentoalveolar expansion of upper dentition but also to orient the functional retrusion of mandible. With simple design the compliance for patients such as mouth breathing problem can be improved. For successful use of this appliance it is utmost important to make accurate and early diagnosis between pseudo- and skeletal class III malocclusion. This article will demonstrate the use of an Inverted labial bow appliance for early treatment of a functional Class III malocclusion. After 4 month treatment, anterior crossbite was treated and the results were achieved mainly dentoalveolar change of upper and lower anterior teeth.
CLINICAL APPLICATION OF MTA(MINERAL TRIOXIDE AGGREGATE) FOR APEXIFICATION
Baik, Byeoung-Ju ; Jeon, So-Hee ; Kim, Young-Sin ; Kim, Jae-Gon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 700~708
Traumatic injuries in young patients can result in the interruption of the development of the incompletely formed roots. In teeth with incomplete root-end formation and necrotic pulps, the root canals must be completely debrided. Because of a lack of an apical stop and the presence of thin and fragile walls in these teeth, it is imperative to perform apexification to obtain an adequate apical seal. Calcium hydroxide has become the material of choice for apexification. Despite its popularity for the apexification procedure, calcium hydroxide therapy has some inherent disadvantages that include variablility of treatment time, unpredictability of apical closure, difficulty in patient follow-up, and delayed treatment. An alternative treatment to long-term apexification procedure is the use of an artificial apical barrier that allows immediate obturation of the canal. MTA(Mineral Trioxide Aggregate) is a powder consisting of fine hydrophilic particles of tricalcium silicate, tricalcium aluminate, tricalcium oxide and silicate oxide. MTA has a pH of 12.5 after setting, similar to calcium hydroxide. This may impart some antimicrobial properties. MTA has low solubility and a radiopacity slightly eater than that of dentin. Also, MTA leaked significantly less than other materials and induced hard-tissue formation more than other materials.
TEMPOROSPATIAL PATTERNS OF PROGRAMMED CELL DEATH DURING EARLY DEVELOPMENT OF THE MOUSE EMBRYOS
Baik, Byeong-Ju ; Lee, Seung-Ik ; Kim, Jae-Gon ; Park, Byung-Yong ; Park, Byung-Keon ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 709~727
The pattern of programmed cell death(PCD) has been examined during the early developmental period of development in mouse embryos, from embryonic day 4.5(E4.5) to E11.5 Embryos from Balb/c breedings were harvested at various embryonic stages between E4.5 and El1.5. Cell death was analysed by in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL) staining in tissue sections and whole embryos. At the blastocyst stage(E4.5), a very few apoptotic cells were found in the inner cell mass of the blastocyst. In the early egg cylinder stage(35.0-5.5), a few apoptotic cells were detected in the embryonic ectoderm, the embryonic endoerm and the proamniotic cavity. In the advanced egg cylinder stage(E5.5-6.5), TUNEL-posifive cells were observed in the extra-embryonic ectoderm and extra-embryonic endoderm as well as in the embryonic ectoderm, embryonic visceral endoderm and proamniotic cavity. In the streak stage(E6.75-7.75), many TUNEL-positive cells were found in the ectoplacental cone. In contrast, only very few apoptotic cells were found in the chorion and extra-embryonic endoderm in extra-embryonic regions. In intra-embryonic region, a few apoptotic cells were randomly found in the embryonic ectoderm, mesoderm and visceral endoderm. At the early somitogenesis stage(E8.0-8.5), most apoptotic cells were observed in the most cranial portion of neural fold (neural ectoderm and adjacent ectoderm). At the mid somitogenesis stage(39.0-9.5), the otic placode first showed TUNEL-positive at this stage. Small number of TUNEL-positive cells were also first seen around optic placode and branchial arches. Three streams of TUNEL-positive cells were clearly seen in the cranial region at 59.5-9.75. At E10.5, apoptotic cells were localized in the developing eye, the junctional portion of medial nasal, lateral nasal and maxillary processes, the lateral portion of branchial arches, the junction of bilateral mandibular processes, and apical ectodermal ridges of limb buds. At E11.5, apoptotic cells were noticeably decreased in most area, except the developing limbs and several somites in the tail region. In this study, the global temporospatial pattern of PCD throughout early development of mouse embryos was discussed. It may provide the basis for further studies on its role in the morphogenesis of the embryo.
ANALYSIS OF ER:YAG LASER IRRADIATION ON CUTTING EFFICACY OF ENAMEL AND DENTIN
Hong, Seong-Su ; Lee, Sang-Ho ; Lee, Chang-Seop ; Kim, Su-Gwan ;
THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, volume 28, issue 4, 2001, Pages 728~734
The purpose of this study was to investigate the effects of Er:YAG laser on cutting of efficacy of enamel and dentin in primary and permanent teeth. We used the enamel and dentin specimens of human teeth which contain the physiologic saline and maintain the pulpal pressure in dentinal tubules. Each specimen was exposed to Er:YAG laser with non-contact mode under different treatment condition of irradiation energy, pulse repetition rate. We investigated the cutting efficacy of Er:YAG laser by Scanning Intensity Microscopy, and obtained following results. 1. Cutting volume of enamel and dentin in primary and permanent teeth were increased by increasing the irradiation energy, pulse repetition rate. 2. Cutting volume of primary teeth was larger than that of permanent teeth. 3. Cutting volume of dentin was larger than that of enamel in primary and permanent teeth. From these results, Er:YAG laser would be more effective in cutting dentin than enamel, and in cutting primary teeth than permanent teeth for clinical application.