• Journal of Technologic Dentistry
• /
• v.46 no.3
• /
• pp.67-72
• /
• 2024

Purpose: In the dental field, acrylic resin can be used to produce various orthodontic appliances. The manufacturing of orthodontic resin requires the insertion of dental wires. However, currently, no study has compared the mechanical properties when dental wires are inserted into the orthodontic resin. Methods: In this study, specimens measuring 3.3 mm×10 mm×65 mm were produced by inserting 0.7- and 0.9-mm wires. A dental wire was used to create a specimen with the following configurations: single wire, two wires bonded together, and two wires spaced 5 mm apart. The flexural strength, flexural modulus, proportional limit, and work of fracture of the fabricated specimens were measured using a universal testing machine. Results: The dental resin inserted with wires demonstrated increased mechanical properties including bending strength, elastic modulus, yield strength, and fracture energy. The bending strength of the fabricated orthodontic resin specimens increased as the diameter of the wire expanded. Conclusion: Thus, the insertion of dental wires into dental resin increased the strength of the manufactured orthodontic appliance.

• The Journal of the Korean dental association
• /
• v.53 no.3
• /
• pp.178-186
• /
• 2015

Dental polymer-based luting materials are classified into esthetic resin cement, adhesive resin cement and self-adhesive resin cement. Due to the different component of each type of resin cement, the preconditioning method of tooth surface and the steps are different from each type of resin cement. The pre-treatment of adherend (ceramic, resin and metal) surface also varies with the type of resin cement and the manufacturer. In this study, the characteristics of each type of resin cement, mechanical properties, indication and advantages were investigated. Through these, clinical tips on using resin cements were suggested.

• Journal of Korean society of Dental Hygiene
• /
• v.9 no.4
• /
• pp.559-568
• /
• 2009

Objectives : In order to manage to reformative tendency of the educational whole with change request of dental hygienics education which is diversificated and professionalized the manufacturing practice of a temporary resin jacket which is educated with from much dental hygiene is become accomplished, so far also the recognition which relates with the manufacturing practice of a temporary resin jacket of dental hygiene students there is not researched. The present research carried out the practice evaluation with the target of students of a dental hygiene department, who finished a manufacturing practice of a temporary resin jacket, analyzed and investigated the material, reported its result, and enforced a research. Methods : This research selected students of 6 dental hygiene departments located in the Daegu Gyeongbuk region, who have manufacturing experience of a temporary resin jacket, by a convenient sampling method, and then a questionnaire was executed by a self-administration method, and a total of 290 copies were statistically treated. The content of the questionnaire are composed of 2 questions on an attitude survey before and after manufacturing practice of a temporary resin jacket, 3 questions on an educator for practice of a temporary resin jacket, 7 questions on recognition of technical skills for manufacturing a temporary resin jacket, 9 questions on the practice content evaluation of manufacturing of a temporary resin jacket and recognition on manufacturing practice of a the temporary resin jacket. Results : 1. The average of recognition on technical skills for manufacturing a temporary resin jacket of a dental hygienist was 3.82 points, the average of evaluation on practice content of manufacturing a temporary resin jacket being 3.75 points, and the average of recognition on the practice of manufacturing a temporary resin jacket was 3.71 points. 2. Currently, as the educator for the practice of manufacturing a temporary resin jacket, dental hygienists were 188 persons(64.8%) and dental technicians was 102 persons(35.2%), and as educators they want in the future, dental hygienists were 97 persons(33.3%) and dental technicians was 193 persons(66.7%). Persons hoping reeducation for manufacturing a temporary resin jacket were 219 persons(85.9%). 3. There was a significant difference in consciousness of students before and after practice of manufacturing a temporary resin jacket(p<.001). 4. There was a significant difference in practice evaluation and practice recognition according to the educational subject(p<.001). 5. There was a significant reverse correlation in the educational subject, practice evaluation and practice recognition(p<0.01). Conclusions : The practice for manufacturing a temporary resin jacket in education of dental hygiene is necessary to improve job performance ability in more various and specialized dental treatment and to solve desire for improvement of professional technical skill ability of students, and accordingly. About study process of the future students observation investigation or student objective interview investigation etc. seeks a problem in the become research lead, the succeeding research which gropes the plan which is the possibility of solving the problem which discovered is thought will be necessary.

• The Journal of the Korean dental association
• /
• v.50 no.7
• /
• pp.377-383
• /
• 2012

Recently, ceramic materials have become a popular choice for dentists performing esthetic indirect restorations. The longevity and success of ceramic dental restorations depends on the adhesive procedures of resin cements. However, dental ceramics can be classified in various ways, depending on the compositions. Also, the applications for resin cement require multiple clinical steps. Therefore, understanding the different ceramic substrates involved in each procedure, as well as the proper adhesive steps for the resin cements is important to us for long-term clinical success.

• Journal of Technologic Dentistry
• /
• v.35 no.3
• /
• pp.209-218
• /
• 2013

Purpose: The purpose of this study was to know the availability of two photosensitizers, PD, DA, as a photosensitizer instead of CQ in UDMA dental composite resin. We want to know photopolymerization effect of UDMA unfilled resin and surface hardness of composite resin containing PD and DA were compared with those of CQ, most widely used photosensitizer for dental composite resins. Methods: The photopolymerization effect of UDMA studied by FT-IR spectroscopy increased with irradiation time and the amount of photosensitizer. Knoop hardness of experimental composite resins prepared by the addition of the photosensitizer content and irradiation time. Results: The relative photopolymerization effect of UDMA increased in the order of PD > CQ > DA. The composite resin of UDMA containing DA or PD, which shows better Knoop hardness than that containing CQ. Conclusion: PD and DA show as effective photosensizers, suitable for UDMA dental composite resin compare with a higher efficiency than CQ.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.3
• /
• pp.313-327
• /
• 1999

The aim of this study was to compare wear resistance of resin denture teeth opposing various restorative materials. The wear resistance of conventional acrylic resin teeth(Trubyte Biotone) and three high-strength resin teeth(Bioform IPN, Endura, SR-Orthosit-PE) opposing different restorative materials(gold alloys, dental porcelain, composite resin) was compared. Wear tests were conducted with a sliding-induced wear testing apparatus which applied 100,000 strokes to the specimen in a mesio-distal direction under conditions of 100 stroke/min and constant loading of 1Kgf/tooth. Wear resistance of the resin denture teeth was evaluated by the following criteria : 1) wear depth, 2) weight loss, and 3) SEM observation. Results were as follows. 1. When opposed to gold alloys and composite resin, high-strength resin teeth showed superior wear resistance compared to acrylic resin teeth. But, in cases opposing dental porcelain, differences between the wear of the high-strength and acrylic resin teeth were not statistically significant (p<0.05). 2. When comparing wear resistance among high-strength resin teeth, opposing gold alloys, Endura was slightly more resistant and while in cases opposing dental porcelain, SR-Orthosit-PE was showed to be slightly resistant(p<0.05). 3. The wear of high-strength resin teeth was greater by 5 to 7 times when opposing porcelain and 2 to 3 times when opposing composite resin compared to gold alloys(p<0.05). 4. SEM observations of the wear surface showed that wear of resin teeth opposing gold alloys is a fatigue type of wear and wear of resin teeth opposing dental porcelain is fatigue and abrasion type of wear. Trubyte Biotone showed more severe fatigue type of wear than high-strength resin teeth. In conclusion, the use of dental porcelain should seriously be considered as restorative material in cases opposing resin denture teeth and improvement seems to be needed on resin teeth in the areas of wear resistance.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.5
• /
• pp.305-314
• /
• 2022

PURPOSE. The aim of this study was to evaluate the flexural strength of a 3D-printed denture base resin (Cosmos Denture), after different immediate repair techniques with surface treatments and thermocycling. MATERIALS AND METHODS. Rectangular 3D-printed denture base resin (Cosmos Denture) specimens (N = 130) were thermocycled (5,000 cycles, 5℃ and 55℃) before and after the different repair techniques (n = 10 per group) using an autopolymerized acrylic resin (Jet, J) or a hard relining resin (Soft Confort, SC), and different surface treatments: Jet resin monomer for 180 s (MMA), blasting with aluminum oxide (JAT) or erbium: yttrium-aluminum-garnet laser (L). The control group were intact specimens. A three-point flexural strength test was performed, and data (MPa) were analyzed by ANOVA and Games-Howell post hoc test (α = 0.05). Each failure was observed and classified through stereomicroscope images and the surface treatments were viewed by scanning electron microscope (SEM). RESULTS. Control group showed the highest mean of flexural strength, statistically different from the other groups (P < .001), followed by MMA+J group. The groups with L treatment were statistically similar to the MMA groups (P > .05). The JAT+J group was better than the SC and JAT+SC groups (P < .05), but similar to the other groups (P > .05). Adhesive failures were most observed in JAT groups, especially when repaired with SC. The SEM images showed surface changes for all treatments, except JAT alone. CONCLUSION. Denture bases fabricated with 3D-printed resin should be preferably repaired with MMA+J. SC and JAT+SC showed the worst results. Blasting impaired the adhesion of the SC resin.

• The Journal of the Korean dental association
• /
• v.53 no.3
• /
• pp.187-194
• /
• 2015

This paper reflects on the state of the art of two kinds of tooth hard tissue (enamel and dentin) bonding with resin cement. After presenting composition of resin cement, concepts of enamel bonding and resin bonding are addressed. Special attention is devoted to the concept and advantage of self-etching technique. Finally, recommended clinical performance regarding bonding to tooth with resin cement is summarized.

• Journal of Technologic Dentistry
• /
• v.23 no.2
• /
• pp.49-59
• /
• 2002

The photopolymerization efficiency and surface hardness of composite resin containing 1,2-phenylpropanedione (PD) and diacetyl (DA) as photoinitiators were studied by IR and Vickers hardness and the results were compared with that of camphorquinone (CQ). Relative photopolymerization efficiency of the photoinitiators increased in the order of DA < CQ < PD. Vickers hardness of composite resin containing the photoinitiators increased in the order of CQ < PD < DA. Thus, PD is a new visible light photoinitiator for dental composite resin with higher photopolymerization efficiency and surface hardness than that of CQ. Mechanical properties such as Vickers hardness, diametral tensile strength, and flexural strength of the experimental resin composite prepared by addition of the photosensitizer into a resin of bis-GMA improved with increasing the photosensitizer content and irradiation time. The resin composite of bis-GMA containing DA or PD shows better mechanical properties than that of CQ.

• The Journal of the Korean dental association
• /
• v.44 no.4 s.443
• /
• pp.256-264
• /
• 2006