• The Journal of the Korean dental association
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• v.50 no.1
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• pp.6-12
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• 2012

As in all other parts in the body, oral tissue also undergoes dramatic changes with increasing age. Since these changes occasionally go beyond physiological scope, which may result in pathological changes, it is essential for dentist to understand changes caused by normal aging process. With increasing age, tooth morphology and occlusion also varies, especially loss of hard tissue, which is taking place in lifelong time, occurs as a result of tooth wear. When this loss of hard tissue is presented rapidly or excessively, functional and esthetical problems are raised, resulting in lowering quality of life of patient as well as making dental treatment for oral rehabilitation even more complex. Therefore, based on understanding of change in occlusion with increasing age, strategic approaches for maintenance of oral health in both functional and esthetic aspect are required as appropriate restoration and maintenance for progressive tooth wear enables desirable occlusal relationship. Carefully planned-restorative treatment in accordance with changed occlusal relationship is also required in the same context. Instead of taking changes in oral tissue as only a consequence of ageing, it is vital to educate patient and his or her guardian, assuring maintenance of oral hygiene and regular dental check-up are of utmost importance for improved oral health.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.1
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• pp.51-70
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• 1999

Dental porcelain is one of the materials of choice for restoration where esthetics is of concern, but has a considerable potentials of wear. The wear of enamel is variable when opposed by different porcelain systems and surface conditions, and the exposed dentine and opaque porcelain due to clinical failure is expected to have high potentials of wear. The purpose of this study was to investigate the wear effects of self-glazed, polished incisal porcelain. polished dentine and opaque porcelain against human enamel in the laboratory by use of a pin-on-disk type wear tester. 4 types of dental porcelain($Vita-{\Omega}$, Ceramco-II, Vintage powder $Vita-{\alpha}$ of In-Ceram system) and type IV gold alloy as cotrol group were used for test specimens. Intact buccal cusps of maxillary premolar were used for enamel specimens, and the cusp converged to a point and was devoid of visible abrasion, caries, decalcification. The upper part was the cusp of a maxillary premolar and the lower part was a porcelain specimen. The enamel wear was deter-mined by weighing the cusp before and after each test. Surface profilometer was used to quantitate wear of the porcelain specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces. The results were as follows : 1 Self-glazed porcelain produced more enamel wear than polished porcelain, especially the enamel wear of $Vita-{\alpha}$ self-glazed porcelain was 3.2 times more than that of other groups. 2. Opaque porcelain produced least porcelain wear, $Vita-{\alpha}$ self-glazed porcelain produce greatest porcelain wear, but there was no statistically significant difference between the groups(p>0.05). 3. The enamel wear of dentine porcelain was 3.8 times more than that of polished inisal porcelain(p<0.05), and the enamel wear of opaque porcelain was 1.9 times more than that of polished inisal porcelain, but there was no statistically significant difference between the groups(p>0.05) 4. Overglazed porcelain produced less enamel wear than self-glazed porcelain, and more enamel wear than polished porcelain, but there was no statistically significant difference between the groups(P>0.05). 5. The hardness number of $Vita-{\Omega}$ dentine and Ceramco-II opaque porcelain was larger, but that of Vintage dentine and $Vita-{\alpha}$ self-glazed porcelain was similar to other groups. 6. Examination of SEM photographs revealed that overglazed porcelain had smoother surface than self-glazed porcelain, and self-glazed porcelain had smoother surface than polished porcelain. Much polishing scratches and larger porosities were observed on the opaque porcelain specimen, and much polishing scratchess and small porosities were observed on the dentine porcelain specimen.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.366-374
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• 2000

FRC/ceromer system provides the clinician with a durable, flexible, and esthetic alternative to conventional porcelain fused to metal crowns. FRC is the matrix which is silica-coated and embedded in a resin matrix. The ceromer material which is a second generation indirect composite resin contains silanized, microhybrid inorganic fillers embedded in a light-curing organic matrix. FRC/ceromer restoration has a several advantages: better shock absorption, less wear of occluding teeth, translucency, color stability, bonding ability to dental hard tissues, and resiliency. It has versatility of use including inlay, onlay, single crown, and esthetic veneers. With adhesive technique, it can be used for single tooth replacement in forms of inlay adhesion bridge. In single tooth missing case, conventional PFM bridge has been used for esthetic restoration. However, this restoration has several disadvantages such as high cost, potential framework distortion during fabrication, and difficulty in repairing fractures. Inlay adhesion bridge with FRC/ceromer would be a good alternative treatment plan. This article describes a cases restored with Targis/Vectris inlay adhesion bridge. Tooth preparation guide, fabrication procedure, and cementation procedure of this system will be dealt. The strength/weakness of this restoration will be mentioned, also. If it has been used appropriately in carefully selected case, it can satisfy not only dentist's demand of sparing dental hard tissue but also patient's desire of seeking a esthetic restorations with a natural appearance.

• The Journal of the Korean dental association
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• v.54 no.6
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• pp.438-446
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• 2016

Severe tooth wear may cause the pathologic change of the TMJ and masticatory muscles, unesthetic facial appearance, pathogenic pulp and occlusal disharmony. Treating patients with severely worn dentition often requires full mouth rehabilitation with increasing vertical dimension. Proper diagnosis and treatment planning are important for esthetic and functional definitive restorations and the long term stability of the neuromuscular system and the TMJ. In this case, 66 year-old female presented with generalized worn dentition. Based on assessment, pathologic destruction of teeth structure on entire dentition was caused by masticatory force and diet habit without loss of vertical dimension. Subsequently, 3 mm increase of vertical dimension that based on incisor for tooth restoration and esthetic improvement was determined. After 8 weeks stabilization period with temporary fixed prostheses, definitive prostheses were fabricated. After 6 months follow up period, satisfactory outcomes were attained both functional and esthetic aspects through this procedure.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.247-256
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• 2003

The patient had bruxism and epilepsy tendency. Inadequate or unstable posterior support was identified due to severe anterior attrition and decreased occlusal vertical dimension. Prematurities of posterior occlusal and wear facets increased the function of anterior teeth, resulting in severe wear. Wear facets displayed sharply defined peripheries, which are matched on articulated diagnostic casts. Also the patient showed C III malocclusion tendency, and lost some facial contour with drooping corners on the mouth. In this case, the alteration of OVD (Occlusal Vertical Dimention) may provide a biologically compatible adjunct to the treatment such as dentofacial esthetics, improved visual proportion in facial heightand mechanical solutions to the force-management of the masticatory system. The patient requires extensive restorative treatment to regain appropriate function, esthetics and comfort. According to the report by Farhad Fays, the average vertical distance from the maxillary to the mandibular mucolabial reflection in the region of the central incisors is approximately 34mm. However, the vertical distance of this patient was found to be 32mm, which was necessary to add gauge 20-sheets to apply vertical dimension. A removable occlusal overlay splint, which restores OVD to the estimated optimalposition, is the general first trial. The patient was observed periodically for 6 weeks, while appropriate adjustments were made vertical dimension to function. When patient felt comfortable with the splint, the teeth were prepared, and provisional restorations are placed for 3 months. The provisional restoration was fabricated by a diagnostic wax-up. When the patient felt comfortable with the provisional restoration, the final restoration mimics OVD, function, and esthetics that have been developed in the treatment restorations. Restoration of the extremely worn dentition presents a substantial challenge to thedentists. Therefore, careful evaluation of the etiology, history, and factors associated with occlusal vertical dimension should be preceded prior to the appropriate treatment planning.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.255-262
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• 2016

This clinical report focuses on the treatment of a patient with esthetic and functional impairments due to severe worn dentition. Absence of posterior support for a prolonged period require comprehensive prosthetic restoration. Accurate clinical and radiographic examinations, diagnostic wax-up, and occlusal vertical dimension evaluation were performed and the degree of patient adaptability was evaluated using an interim restoration. After 8 weeks of stabilization with interim restoration and confirmation of absence of any abnormal findings, definitive prostheses were fabricated. Satisfactory functional and esthetic outcomes were observed after 6 months of follow-up.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.253-268
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• 2012

Full-mouth reconstruction of a patient using dental implants is a challenge if there is vertical and horizontal bone resorption, since this includes the gingival area and restricts the position of the implants. however, hard- and soft-tissue grafting may allow the implants to be placed into the desired position. Although it is possible to regenerate lost tissues, an alternative is to use fixed detachable prostheses that restore the function and the esthetics of the gingiva and teeth. Various material combinations including metal/acrylic, metal/ceramic, and zirconia/ceramic have been used for constructing this type of restoration. Other problems include wear, separation or fracture of the resin teeth from the metal/acrylic prosthesis, chipping or fracture of porcelain from the metal/ceramic or zirconia/ceramic prosthesis, and fracture of the framework in some free-end prostheses. With virtually unbreakable, chip-proof, life-like nature, monolithic zirconia frameworks can prospectively replace other framework materials. This clinical report describes the restoration of a patient with complete fixed detachable maxillary and mandibular prostheses made of monolithic zirconia with dental implants. The occluding surfaces were made of monolithic zirconia, to decrease the risk of chipping or fracture. The prostheses were esthetically pleasing, and no clinical complications have been reported after two years.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.4
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• pp.309-315
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• 2003

When the exposure surface of restoration is brushed with various toothpaste in the mouth, wear or undesirable surface deposit of restoration can occur. Surface change of gallium alloys according to brushing and toothpaste may directly affect oral hygiene. The aim of this study was to evaluate the surface alterations of Gallium alloys during tooth brushing with different prophylactic agents. Two gallium-alloys and an amalgam as a control were investigated. Without and with brushing were applied with three kinds of prophylactic agents on the sample for 0, 1, 5, 10, 60 and 360 minutes. At each time interval, surface roughness was recorded by a profilometer and some pictures were taken by a SEM. All results were analyzed by the one-way ANOVA, followed by Tukey multiple comparisons and the simple linear regression analysis. The results indicate that gallium alloys are more susceptible to surface degradation during tooth brushing than amalgam with respect to the specific prophylactic agent used.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.31-39
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• 2018

The collapse of the posterior occlusion destroys the normal occlusal plane and causes excessive wear reducing the vertical dimension. Reduced vertical dimension of occlusion causes not only aesthetic and functional problems but also overloading on the temporomandibular joints and abnormalities of muscle nerve system. In order to improve the collapsed occlusal relationship, it is necessary to consider the change of the vertical dimension. It is necessary to make a precise diagnosis and analysis before the treatment and to evaluate the adaption of patient to the new vertical dimension of occlusion. A patient with excessive overbite often has occlusal problems of tooth wear and tooth eruption. Considering these considerations, overall prosthodontic restoration is required to solve the problem. A patient of 68 year old man in this case who suffered major tooth wear and maxillary posterior teeth loss was treated with elevation of vertical dimension of occlusion by maxillary removable dental prosthesis and mandibular fixed prosthesis.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.284-292
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• 2023

Stable posterior occlusal support is crucial for adequate masticatory function and facial aesthetics. In elderly patients over the age of 65, masticatory ability has a significant impact on nutritional intake and overall health. This case report presents a prosthetic treatment of an elderly patient with edentulous maxilla and bilateral posterior edentulous mandible. The upper jaw was restored with a complete denture to establish an ideal occlusal plane, and the three-dimensional positions of the mandibular implants were determined accordingly. The implants were placed through computer-guided implant surgery and were immediately loaded with fixed provisional restorations. The implant-fixed zirconia final restorations were inserted in the lower posterior region, and the occlusal surface of posterior artificial teeth in the upper denture was substituted with cobalt-chrome alloy to resist occlusal wear. The patient's posterior occlusal support and masticatory function were promptly restored through this treatment process, and long-term stability against wear was also obtained.