Surgical extrusion, immediate extrusion following tooth luxation, is a method to preserve one's natural tooth and achieve esthetic restoration without additional periodontal surgery when subgingival dental caries or crown fracture occurs. A 16-year-old male was referred to the clinic from the department of operative dentistry for the esthetic restoration of maxillary left lateral incisor. Due to the crown to root fracture, the tooth was endodontically treated with a buccal crown length of 4 mm. When the palatal flap was elevated, the mesiopalatal cervical fracture area was situated 3 - 4 mm subgingivally. Crown lengthening was achieved through surgical extrusion. After 3 months of clinical observation and provisional restoration, the maxillary left central incisor was restored with all ceramic crown and obtained a satisfactory clinical result.
Adolescent ; Ceramics ; Crown Lengthening ; Crowns ; Dental Caries ; Dentistry, Operative ; Humans ; Incisor ; Male ; Tooth ; Tooth Avulsion

OBJECTIVETo evaluate the efficacy of flowable composite resin(FCR) as stress-absorbing liners in Class I cavity restorations in vitro.

METHODSThirty Class I cavities of 4 mm in diameter and 2 mm in depth were prepared in polycarbonate (PC) plates and divided into three groups, ten each. After application of an adhesive, cavities in each group were restored using one of the following methods: A: restored with Charisma without any lining of FCR; B: lined with Revolution Formula 2 twice before restoration with Charisma; C: lined with Teric Flow twice before restoration with Charisma. All cavities were observed under a photoelastic microscope and photoelastic images were recorded at 3 min and 24 h after curing and the shrinkage stresses on the cavity wall were calculated. The polymerization shrinkage(v%) of the three composite resins was measured using bonded discs method and their elastic moduli were measured according to ISO standard.

RESULTSThe shrinkage stresses at 3 min and 24 h of the three methods were as follows,A: (4.93 ± 0.28), (5.87 ± 0.40) MPa, B: (4.90 ± 0.30), (5.84 ± 0.33) MPa, and C: (4.76 ± 0.28),(5.83 ± 0.37) MPa.No significant difference was found in results among different groups. The polymerization shrinkage(v%) in group A,B, and C were (2.63 ± 0.04)%, (4.56 ± 0.06)%, and (3.98 ± 0.02)%. The elastic modulus in group A, B, and C were (9.59 ± 0.65), (4.25 ± 0.51), and (5.41 ± 0.79) GPa.

CONCLUSIONSUnder present study condition, using a FCR as stress-absorbing liner under composite resin restoration does not significantly decrease the polymerization shrinkage stresses at the cavity wall.

Composite Resins ; chemistry ; Dental Cavity Lining ; Dental Restoration, Permanent ; methods ; Dental Stress Analysis ; Materials Testing ; Polymerization

OBJECTIVETo develop a dental CAD/CAM system with the autonomic intellectual property.

METHOD28 standard teeth crowns were scanned using a newly 3-D laser scanner. As a development platform the Matlab 5.3 were used to process the acquired data, also be used to define the characterized areas on the surfaces of the crowns and to change the crowns form. The software of Surfacer 10.5 to develop a new CAD software for fixed prosthetics, and the 3.5 axis numerical controlled machine to manufacture the prosthetics were used.

RESULTIt is the first time, the 3D graphic data bank of Chinese teeth crowns with a standard form was established. A software of the occlusal adjustment and the form modification were developed. It is also the first time, the authors realized the whole process to use the CAD-CAM for the manufacture of a crown.

CONCLUSIONThe successful result shows, that we have already mastered well the base theory, the mathematics method, the technology of a CAD-CAM system. It provides the basics for the future development.

Computer-Aided Design ; Dental Prosthesis Design ; methods ; trends ; Dental Restoration, Permanent ; methods ; Dentistry, Operative ; methods ; Humans ; Research ; trends ; Research Design

Adult ; Crown Lengthening ; Dental Restoration, Permanent ; Esthetics, Dental ; Female ; Humans ; Incisor ; Malocclusion ; therapy

OBJECTIVEThe purpose of this study was to compare the clinical application and effect of two temporary restorations materials: composite and self-cured acrylic resin.

METHODS153 composite temporary crowns (and bridges) placed in 44 patients and 144 self-cured acrylic resin temporary crowns (and bridges) placed in 49 patients were evaluated according to the California Dental Association's (CDA) criteria and questionnaire.

RESULTSIt showed that composite temporary crowns (and bridges) had better surface smoothness, marginal integrity and anatomic form than self-cured acrylic resin temporary crowns (and bridges). In the 49 patients with self-cured acrylic resin temporary crowns (and bridges), 67% and 88% of them complained of food impaction and mouth odor, while only 2% and 30% in the 44 patients with composite temporary crowns (and bridges) had the same complaint.

CONCLUSIONBetween the two temporary restoration materials, composite is better than self-cured acrylic resin.

Acrylic Resins ; Composite Resins ; Crowns ; Dental Bonding ; Dental Marginal Adaptation ; Dental Restoration, Temporary ; methods ; Humans ; Surveys and Questionnaires

Child ; Dental Pulp Exposure ; etiology ; therapy ; Dental Restoration, Permanent ; Dental Restoration, Temporary ; Humans ; Incisor ; injuries ; Pulpotomy ; methods ; Root Canal Therapy

To understand the recent characteristics of the papers published in the Journal of Korean Academy of Conservative Dentistry(JKACD), All the papers in the JKACD of 1992 to 2001 were analyzed. A total of 513 papers were classified according to its type, field and subject of the study, school and the number of authors, references, and written language. The results were as follows; 1. According to the type of the paper, 506(98.6%) were original articles, 3(0.6%) were review articles, and 4(0.8%) were case reports. 2. Anual proportion of papers in the field of operative dentistry was similar to that of endodontics. 3. In the field of operative dentistry, esthetic restorative materials and bonding to tooth constituted major subjects of the studies. In the field of endodotics, pulp biology was prominent and canal shaping, endodontic microbiology and canal obturation were steadily reported. 4. According to author's school, similar number of papers were published in the field of operative dentistry and endodontics in general. However, some schools showed preponderances. 5. Most studies were done by two or more authors. Studies published by two authors were most. 6. Fifty(9.7%) papers were done in collaboration with workers of the other field. 7. Average number of references cited in the papers was 41.2, including domestic references of 1.8. 40.7% of the papers was shown to cite no domestic papers at all. 8. Twenty-eight(5.5%) papers were written in English, with increasing ratio.
Biology ; Cooperative Behavior ; Dentistry ; Dentistry, Operative ; Endodontics ; Humans ; Tooth

Crown Lengthening ; methods ; Crowns ; Dental Caries ; therapy ; Dental Restoration, Permanent ; Humans ; Root Canal Therapy ; Tooth Fractures ; therapy

PURPOSE: This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital(YUDH) using the half value layer(HVL) and the characteristic curve of intraoral standard X-ray film. MATERIALS AND METHODS: The study was done using the intraoral X-ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. RESULTS: Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. CONCLUSION: HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.
Aluminum ; Dentistry ; Dentistry, Operative ; Humans ; Pediatric Dentistry ; Prosthodontics ; X-Ray Film

Crown Lengthening ; Humans ; Tooth Crown