• The Journal of Advanced Prosthodontics
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• v.14 no.5
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• pp.305-314
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• 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 Korean Academy of Prosthodontics
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• v.41 no.6
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• pp.732-746
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• 2003

Statement of problem. Soft lining materials, also referred to as tissue conditioning materials, tissue heating materials, relining materials, soft liners or tissue conditioners, were first introduced to dentistry by a plastic manufacturer in 1959. Since the introduction of the materials to the dental field, their material properties have been continually improved through the effort of many researchers. Soft lining materials have become widely accepted, particularly by prosthodontists, because of their numerous clinical advantages and ease of manipulation. Unfortunately, few reports have been issued upon the topic of increasing the bond strength between the base metal alloy used in cast denture bases and PMMA soft liner modified with 4-META, nor upon the pattern of debonding and material change in wet environment like a intra oral situation. Purpose. The purposes of this study were comparing the bond strength between base metal alloy used for the cast denture bases and PMMA soft liner modified with 4-META, and describing the pattern of debonding and material property change in wet environment like the intraoral situation. Material and Methods. This study consisted of four experiments: 1. The in vitro measurement of shear bond strength of the adhesive soft liner. 2. The in vitro measurement of shear bond strength of the adhesive soft liner after 2 weeks of aging. 3. A comparison of debonding patterns. 4. An evaluation the Relation time of modified soft liner. The soft liner used in this study was commercially available as Coe-soft (GC America.IL.,USA), which is provided in forms of powder and liquid. This is a PMMA soft liner commonly used in dental clinics. The metal primer used in this study was 4-META containing primer packed in Meta fast denture base resin (Sun Medical Co., Osaka, Japan). The specimens were formed in a single lap joint desist which is useful for evaluating the apparent shear bond strength of adhesively bonded metal plate by tensile loading. Using the $20{\times}20mm$ transparent grid, percent area of adhesive soft liner remaining on the shear area was calculated to classify the debonding patterns. To evaluate the change of the initial flow of the modified adhesive soft liner, the gelation time was measured with an oscillating rheometer (Haake RS150W/ TC50, Haake Co., Germany). It was a stress control and parallel plate type with the diameter of 35mm. Conclusion. Within the conditions and limitations of this study, the following conclusions were drawn as follows. 1. There was significant increase of bond strength in the 5% 4-META, 10% 4-META containing groups and in the primer coated groups versus the control group(P<0.05). 2. After 2 weeks of aging, no significant increase in bond strength was found except for the group containing 10% 4-META (P<0.05). 3. The gelation times of the modified soft liner were 9.3 minutes for the 5% 4-META containing liner and 11.5 minutes for the 10% 4-META liner. 4. The debonding patterns of the 4-META containing group after 2 weeks of aging were similar to those of immediaely after preparation, but the debonding pattern of the primer group showed more adhesive failure after 2 weeks of aging.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.283-290
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• 2011

Purpose: This study compared the marginal bone loss around dental implant that were placed in the canine areas of the mandibles and finded the survival rate of implants, marginal bone loss around implants and prosthetic complications in 10 patients treated with overdentures retained with Locator attachments. Materials and methods: Ten patients who had received implant retained overdentures in the mandibules using two implants and Locator attachments at Daegu Catholic University Medical Center from 2004 to 2010 were included in this study. Evaluations of the survival rate of implants, marginal bone loss and prosthetic complications were performed. Results: Implants placed in this study showed a 100% survival rate and the average annual bone loss was 1.03 mm ${\pm}$ 0.20 mm in the first year. The patients have verbally indicated that they are comfortable and that their overdentures function well. But, implant retained overdentures had various prosthetic complications such as male change, relining, rebasing and denture fracture. Conclusion: Implant retained overdentures using two implant and Locator attachments in the fully edentulous mandibles is considered as a stable way for long terms because of minimal invasive operation, simple prosthetic process and easy repair.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.385-395
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• 2012

This clinical report presents the case using overlay dentures to treat a patient with cleft lip and palate and malocclusion. This patient requires vigorous treatment such as orthodontic treatment and combined orthodontic/oral surgery procedures. Overlay denture can be used as an alternative treatment option. Intraoral and radiographic examinations were done. The vertical dimension of occlusion was evaluated for proper prosthetic procedures and the surveying in the diagnostic cast was done. Considering the tissue and teeth undercut, the alterations of teeth shape were done. Final preparation and impression was performed. After the evaluation of vertical dimension and occlusion with wax-denture, the dentures were polymerized. Clinical remounting and occlusal adjustment were done on the articulator. Overlay dentures were delivered and the patient was recalled for relining. The overlay dentures satisfied patient's esthetic and functional requirements and provided a stable occlusion. Overlay dentures in this case were a reversible and relatively inexpensive treatment for this patient, however the potential possibilities of caries and periodontal disease as a result of poor oral hygiene should be prevented with periodic recall.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.314-321
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• 2016

Conventional removable partial dentures (RPDs) with distal extensions are associated with some problems, including lack of stability that calls for frequent relining, and cantilever actions of claps that can produce excessive loading to abutment teeth, and the need for unesthetic retentive arm clasps. Therefore, IARPDs (Implant-assisted RPD) that use implants to support or retain RPDs has been reported to improve stability, esthetics and masticatory performance of RPDs. Also, an IARPD that has zirconia occlusal table can prevent the incongruity of occlusal plane and the extrusion of antagonistic tooth. In this case of partially edentulous patient with crossed occlusion, each edentulous area was restored with implant fixed prosthesis and implant retained partial denture to suit each situation. Through the procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.