• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.239-245
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• 2014

Complete denture prosthodontics includes replacement of natural teeth and associated maxillary and mandibular structures for full edentulous patients. The final objectives of prosthodontic treatment include esthetic and functional rehabilitation. Because the esthetic demand of senior patients has increased esthetic requirement should not be overlooked in denture treatment. In complete denture treatment, attempts have been made to reproduce tooth wear, arrangement, recession of cervical gingiva, staining, improved gingival shade and so on. This 61 year old female patient came to the Department of Prosthodontics with the chief complaint that dentures made 5 years ago in a local clinic were broken and did not fit well. The patient put more emphasis on fabrication of natural and esthetic dentures than recovery of masticatory function. Remake of maxillary complete denture and mandibular implant retained overdenture was planned. In order to create esthetic and natural contour, Aesthetic Color Set Easy system$^{(R)}$ (Candulor dental GmbH, Wangen, Germany) was used to make complete dentures reproducing various gingival shades. Patient's esthetic satisfaction was high. When complete denture prosthodontics treatment involves appropriate expression of individual characteristics in addition to proper selection of esthetic materials, treatment will give satisfaction to both dentist and patient.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.554-563
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• 1999

For the purpose of elucidating the polymerization modes of dual-cure restorative materials and comparing them with single-cure restorative materials, a study was performed on the light-cured composite resin, dual-cure composite resin, dual-cure glass ionomer cement and chemical-cure glass ionomer cement. By measuring the microhardness of each material at 0mm, 1mm and 3mm depth during initial 24 hours with predetermined interval, the state of polymerization and degree of conversion was indirectly evaluated for each material, and obtained results are as follows : 1. All of four materials tested showed significant increase in microhardness after 24hrs compared with just after curing starts. 2. In all materials except Ketac-fil, there showed a significant difference in microhardness between each depth at each time interval. 3. In the test of lap time till final curing for each material, the polymerization process was revealed to last longer in the dual-cure type materials than in single-cure type materials at 3mm depth. Based on the results above, it was demonstrated with materials of dual-cure mode that the degree of conversion increases by successive curing reactions even in the deeper layers where sufficient curing light is impermeable.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.410-418
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• 2000

An in vitro study was performed to evaluate the effect of four variables on the temperature rise produced by polishing of restorations. The four variables were : restorative material, base, thickness of remaining dentin, continuous polishing or intermittent polishing. Class V cavities were cut on extracted molar and restored with composite resin, resin-modified glass ionomer cement, compomer, amalgam on the various bases (glass ionomer cement, zinc oxide eugenol cement, zinc phosphate cement) Dentin thickness under the restoration was 0.5mm, 1.5mm. Polishing was done with an aluminum oxide-coated disc. Polishing time was continuous or intermittent for up to 1 minute. Intra-pulpal temperature increased almost linearly in all cases. Amalgam produced highest temperature rises at the pulp, while the composite resin, resin-modified glass ionomer cement and compomer were not different for each other. The rate and extent of temperature rising of amalgam restoration was reduced by presence of a cement base. Zinc oxide eugenol cement bases showed the highest temperature rise, while glass ionomer cement, zinc phosphate cement were not different to the untreated tooth Thickness of remaining dentin was only significant for the amalgam restoration. Continuous polishing produced higher temperature rise than intermittent polishing.

• Restorative Dentistry and Endodontics
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• v.35 no.2
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• pp.65-68
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• 2010

Due to the improvement of the composite resin and esthetic desire of the patient, amalgam restoration has been replaced by composite resin. However, still there are many unsolved problems, for example, technique sensitivity, polymerization shrinkage stress and limited mechanical properties. These factors results in fracture of the restoration and secondary caries of the tooth. Also the use of the dental bonding system should be used for the retention of the restoration. In this paper, I want to talk about the present and the future of the remineralizing component released from dental composite resin to overcome the secondary caries and there possibility in the clinical use.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.190-201
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• 2004

The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four esthetic restorative materials in an alkaline solution. The brands studied were Charmfil, Charmfil flow(composite resin), Compoglass F and PrimaFlow(compomer). The results were as follows: 1. The mass loss were not significantly different among the materials(p>0.05). 2. The sequence of the degree of degradation layer depth was in descending order by Compoglass F, PrimaFlow, Charmfil, and Charmfil flow. There were significant differences between Compoglass F and the others(p<0.05). 3. The sequence of the Si loss was in descending order by Charmfil flow, Charmfil, PrimaFlow, and Compoglass F. There were significant differences among these materials(p<0.05). 4. When observed with SEM, destruction of bonding between matrix and filler was observed and when observed with CLSM, the depth of degradation layer of specimen surface was observed. 5. The sequence of maximum wear depth was in descending order by Comfoglass, PrimaFlow Charmal, and Charmfil flow. There were significant differences among these materials(p<0.05). 6. The correlation coefficient between Si loss and degradation layer depth (r=0.602, p<0.05) Vicker's hardness number and maximum wear depth (r=0.501, p<0.05) were relatively high. These results indicate that wear and hydrolytic degradation may be considered to be evaluation factors of composite resins and compomers.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.3
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• pp.307-317
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• 2023

Due to increasing demand for aesthetics, zirconia crowns have become a popular choice for treating primary molars. However, there is limited literature available comparing the survival rates of zirconia crowns with those of other restorative materials. The objective of this study was to compare the 36-month survival rates of zirconia crowns and stainless steel crowns for proximal caries, as well as to analyze failure types associated with each crown type. Electronic medical records and radiographs of 1,061 primary molars from 498 patients treated with 2 types of prefabricated crowns at Chosun University Dental Hospital and 2 private dental clinics between 2017 and 2019 were collected and analyzed. The survival rate of zirconia crowns was found to be lower compared to that of stainless steel crowns. Regarding the groups without pulp treatment, the survival rate of stainless steel crowns was significantly higher than that of zirconia crowns. However, in the groups that received pulp therapy, no significant difference in the survival rates was observed between the two preformed crowns. Notably, abnormal root resorption or periapical lesions were identified as the primary cause of restorative failure in stainless steel crowns, whereas loss of restoration was the predominant cause in zirconia crowns. This study holds valuable implications for clinicians when selecting preformed crowns for primary molars.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.118-128
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• 2001

This study was performed to evaluate the toothbrush abrasion characteristics of seven commercially available light-cured cervical restorative materials one resin-modified glass-ionomer material(Fuji II LC) three polyacid-modified composites(Compoglass, Dyract, F2000), and three light-cured composites(Heliomolar, Palpique Estelite, UniFil F). All samples were stored in distilled water at $37^{\circ}C$ for 10 days. 2.0N of weight was loaded during the test and the abraded surfaces were examined with profilometer and SEM after 100,000 cycles. The results obtained were summarized as follows; 1. The highest hardness value of 79.7 was observed in the FT group and the lowest value of 20.0 was observed in the HM group. Results of Tukey test showed that an overall significant difference was indicated except the CG and DR groups(p<0.05). 2. The highest surface roughness was observed in the FL group and the lowest was observed in the UF group. Results of Tukey test showed the significant difference between the FL or FT and UF groups(p<0.05). 3. Statistically higher abrasion and surface roughness were observed for the dentifrice of paste type, Perio A+, than for that of gel paste type, Tom & Jerry. 4. The surface roughness values increased on the abraded surfaces because of the protrusion of filler particles due to selective removal of matrix resin.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.165-173
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• 2013

The purpose of this study was to evaluate the surface change after 15% carbamide peroxide home bleaching to various restorative materials (composite resin [CR], resin modified glass ionomer [RMGI] and glass ionomer [GI]) and to observe the effect of surface condition of the materials on re-staining. Three esthetic restorative materials (Filtek Z250, 3M, USA; Fuji II LC, GC, Japan; Fuji II, GC, Japan) were used in this study. Twenty specimens per material group were made and divided into two groups (bleached and control). The specimens were immersed in coffee after applying bleaching agent. The color change and surface roughness were measured before and after bleaching and after immersion in coffee. The data were analyzed with SPSS 18.0. The results were as follows: 1. The color of all experiment groups was significantly changed after bleaching (p<0.05). RMGI was the greatest value of ${\Delta}E^*$ and ${\Delta}L^*$. GI and CR groups were in ordering (p<0.05). The ${\Delta}a^*$ value was decreased GI, RMGI and CR. RMGI was only significantly decreased in ${\Delta}b^*$ value (p<0.05). 2. The surface roughness before and after bleaching was significantly different on CR, RMGI and GI (p<0.05). 3. After staining with coffee, the value of ${\Delta}E^*$ was increased in GI, RMGI and CR, furthermore GI and RMGI showed significant difference in the bleaching groups (p<0.05). The ${\Delta}L^*$ value of GI and RMGI was significantly decreased. 4. The change of surface roughness after staining was not significantly different in all groups (p>0.05). The maintenance of color stability in esthetic restorations is one of the most important properties. Tooth whitening is for the aesthetic. Therefore, dental professionals should notice to patients about re-staining after tooth whitening. They should give an instruction that how to prevent and which kinds of agents could be stained.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.104-112
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• 2023

A 3D-printed resin crown is a novel option for esthetic crown restoration for primary teeth, which are typically bonded with resin cement. The purpose of this study was to evaluate the bonding ability of a 3D printing resin and compare it with other indirect resin materials for crown fabrication. The shear bond strengths of two 3D printing resin materials, Graphy (GP) and NextDent (NXT), and two indirect resin materials, VIPI Block (VIPI) and MAZIC Duro (MZ), were compared in the study. For all materials, the shear bond strength at the interface between the surface of the resin material and resin cement was measured. The mean shear bond strength values of GP, NXT, MZ, and VIPI were 23.29 ± 3.88, 26.14 ± 4.67, 25.41 ± 4.03, and 18.79 ± 4.26 MPa, respectively. There was no significant difference among the SBSs of GP, NXT and MZ except for VIPI. The result of this study indicates that the 3D printing resin meets the essential requirement for clinical use by showing clinically adequate bond strength.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.242-248
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• 2012

Children usually have varying degree of caries in primary anterior teeth, and treatment planning for each case prescribed by each dentist can also be varied. This survey was conducted to compare the preferred treatment method and restorative materials between general dentists and pediatric dentists in regard to the treatment of primary incisors. The questionnaires, composed of 18 questions were sent to 45 general dentists and 50 pediatric dentists. Among which 30 and 31 questionnaires were retrieved respectively. The collected data were analyzed by rate and the results were as follows: 1. For the teeth with initial caries without cavitation, general dentists showed the tendency to prefer restorative treatment(30%) or observation without any treatment(42%), whereas pediatric dentists prefer preventive treatment(76%). 2. The primary factor in choosing restorative materials by both groups was its manipulativeness. 3. For anterior esthetic restoration, general dentists seldom use the full-coverage restoration(13%) but resin restoration(75%), whereas pediatric dentists frequently used full-coverage crow(64%). 4. In the treatment of dentinal caries, pediatric dentist did not perform the treatment lesser than 2.0 years before the exfoliation (compared to 1.2 years of general dentist). 5. In the treatment of 1 year children, both pediatric and general dentists tend to select preventive procedure as first choice of treatment(84%, 52%). When treating primary incisor caries, it is shown that pediatric dentists are more interested in restorative/preventive treatment than general dentists are.