No abstract available.
Centric Relation* ; Tooth Wear*

STATEMENT OF PROBLEM: Tooth wear is physiological phenomenon. Ninety-seven percent of normal people have tooth wear and about 7% has pathologic teeth wear. If we know the amount of tooth surface loss caused by pathologic tooth wear, we may restore it ideally. PURPOSE: Recently, measurement of tooth wear by using 3D scan has been increasing. Therefore, we need to know how accurate 3D scan is. Past accuracy test on 3D scan was about linear change, but as we know that tooth wear is volume change. Thus, the purpose of this study is to know how accurate 3D scan is. MATERIAL AND METHODS: For accuracy test of 3D scanner, volume values measured by 3D scanner and micro-balance were compared. For test I, preliminary, 3 ball samples and 3 circular cones were made with pattern resin. For test II, 10 teeth shape rubber samples were used. RESULTS AND CONCLUSION: 1. The result of the accuracy test on 3D scan with 3 ball samples and 3 circular cones made of pattern resin has no significant difference(p<0.05). 2. The result of the accuracy test on 3D scan with 10 samples of tooth shape rubber has no significant difference(p<0.05). As a result, we may concluded the analysis of quantifying tooth wear used by 3D scan is useful in the clinic.
Physiological Phenomena ; Rubber ; Tooth Wear ; Tooth*

Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. To overcome the problems of the existing qualitative tooth wear analysis method, virtual three-dimensional models have been used. This study was designed to develop and validate a new quantitative method using tooth wear measurement parameters with angles obtained from virtual vectors and planes of the three-dimensional models. Sixteen parameters were evaluated in the virtual models of 20 students (7.57+/-1.55 years old) and 20 adults (56.85+/-6.34 years old). There were 12 angle and 4 height parameters, and the number of parameters measured from the virtual planes and vectors were 10 and 6, respectively. For each parameter, means and standard deviations were calculated, and an unpaired sample t test was performed to compare the young and the adult groups. Also, differences between the means were determined and expressed as percentages. The results were statistically significant between the two groups (P<0.001). In general, parameters using virtual vectors showed greater change than virtual plane. Although there were statistically significant differences among all parameters using virtual planes (P<0.001), the changes of the three angles were similar, except distolingual cusp angle. It was found that the parameters using virtual vectors were effective and tooth wear took place in both buccal and lingual cusps. Likewise, the validation of the new measurement parameters suggests that they can also be applied in the assessment of tooth wear related to dental biomaterials.
Adult ; Biocompatible Materials ; Dentition ; Humans ; Quality of Life ; Tooth Wear* ; Tooth*

Tooth wear is gradually increasing with increasing life expectancy. In particular, it is important to establish a treatment plan in the early stages so that it does not proceed to moderate or severe wear stages. It is essential to diagnose tooth wear accurately in order to plan a treatment for it. There are many risk factors including age, diet, and drugs which affects tooth wear. For the diagnosis of a tooth wear, appropriate index and evaluation method should be used. There were various tooth wear indices such as TWI, Lussi index, BEWE, and TWES. The evaluation method includes clinical examination, dental cast examination and clinical photographs. Recently, a 3D scanner is being used to assess tooth wear. The risk factors, tooth wear evaluation system, the methods of measuring tooth wear, and related literature were reviewed. The strengths and weaknesses of each index and evaluation methods were compared to derive a proper way to diagnose tooth wear.
Diagnosis ; Diet ; Life Expectancy ; Methods ; Risk Factors ; Tooth Wear ; Tooth

PURPOSE: Occlusal splints are commonly used to prevent tooth wear caused by bruxism. However, the effects of splints on occlusion are still unclear. Although it is rarely alluded in literature, splints can provoke severe occlusal alterations and other complications. This study was aimed to identify differences in the responses of individuals with bruxism and healthy individuals to a full-arch maxillary stabilization splint in terms of occlusal changes. MATERIALS AND METHODS: Occlusal contacts in 20 (5 male, 15 female) bruxism patients and 20 (5 male, 15 female) controls with normal occlusion were evaluated before and after occlusal splint therapy. T-Scan III, a computerized occlusal analysis system, was used to simultaneously measure occlusion and disclusion times as well as left-right and anterior-posterior contact distributions before splint therapy and 3 months after therapy. Wilcoxon and Mann-Whitney U tests were used for statistical analyses (alpha=.05). RESULTS: No differences were found in the posterior contact of bruxism patients before and after stabilization splint treatment. However, differences in posterior contact were observed between bruxists and normal individuals prior to treatment, and this difference disappeared following treatment. CONCLUSION: The results of this study showed the use of a stabilization splint may not have an effect on occlusion. However, the area of posterior occlusal contact among bruxists was found to be greater than that of normal individuals. According to this study, the clinical use of splints may be harmless.
Bruxism ; Humans ; Male ; Occlusal Splints ; Splints ; Tooth Wear

Severely worn dentition seriously affects patient's esthetics and function. Its etiology is complex, differential diagnosis is difficult, treatment process involves multiple disciplines, and requires esthetic and functional rehabilitation. A "8-step sequential treatment" for the rehabilitation of severely worn dentition has been established. In recent years, digital technology has been increasingly applied to the esthetic and functional rehabilitation of severely worn dentition. This article will describe the application of digital methods in the 8-step sequential treatment of severely worn dentition.
Humans ; Tooth Wear/rehabilitation* ; Esthetics, Dental ; Dentition ; Digital Technology

PURPOSE: This study was conducted to evaluate the effects of full-coverage all-ceramic zirconia, lithium disilicate glass-ceramic, leucite glass-ceramic, or stainless steel crowns on antagonistic primary tooth wear. MATERIALS AND METHODS: There were four study groups: the stainless steel (Steel) group, the leucite glass-ceramic (Leucite) group, the lithium disilicate glass-ceramic (Lithium) group, and the monolithic zirconia (Zirconia) group. Ten flat crown specimens were prepared per group; opposing teeth were prepared using primary canines. A wear test was conducted over 100,000 chewing cycles using a dual-axis chewing simulator and a 50 N masticating force, and wear losses of antagonistic teeth and restorative materials were calculated using a three-dimensional profiling system and an electronic scale, respectively. Statistical significance was determined using One-way ANOVA and Tukey's test (P<.05). RESULTS: The Leucite group (2.670+/-1.471 mm3) showed the greatest amount of antagonist tooth wear, followed by in decreasing order by the Lithium (2.042+/-0.696 mm3), Zirconia (1.426+/-0.477 mm3), and Steel groups (0.397+/-0.192 mm3). Mean volume losses in the Leucite and Lithium groups were significantly greater than in the Steel group (P<.05). No significant difference was observed between mean volume losses in the Zirconia and Steel groups (P>.05). CONCLUSION: Leucite glass-ceramic and lithium disilicate glass-ceramic cause more primary tooth wear than stainless steel or zirconia.
Crowns* ; Lithium ; Mastication ; Stainless Steel* ; Steel ; Tooth ; Tooth Wear ; Tooth, Deciduous*

Excessive wear causes many complications when untreated, so that accurate diagnosis, analysis and predictive treatment plan should be made, and through evaluation of vertical dimension and stepwise treatment, a stable inter-arch relationship can be set. For the long-term success of implant treatment, ideal position and angle of implant is important, and its importance increases especially in multiple implant cases. Therefore, thorough diagnosis and planning, accurate surgery and prosthodontic procedures are significant. In this case, a 68-year-old male patient with a loss of vertical dimension due to multiple tooth loss and overall tooth wear was planned with systematic analyses from the pre-treatment stage to rehabilitate vertical dimension. Full-mouth fixed rehabilitation with computer tomography guided implant surgery was performed to the newly set vertical dimension and attained satisfactory outcomes both functionally and esthetically.
Aged ; Dentition* ; Diagnosis ; Humans ; Male ; Rehabilitation* ; Tooth Loss ; Tooth Wear ; Tooth* ; Vertical Dimension*

Severely worn dentition is frequently multifactorial. It is crucial that the etiology of excessive wear be determined, but accurately diagnosing the factors responsible for tooth wear is often confusing. Before initiating the treatment of these cases, meticulous examination and determining vertical dimension are essential. A 69-year-old male patient had the chief complaint that he has worn dentition and functional and esthetic discomfort. Based on model analysis and diagnostic wax up, new vertical dimension had been determined. Provisional restorations were cemented and after 5 months permanent prostheses were fabricated. This case reports a satisfactory functional and esthetic clinical outcome achieved by restoring the vertical dimension.
Aged ; Dentition ; Humans ; Male ; Mouth Rehabilitation* ; Mouth* ; Prostheses and Implants ; Tooth Wear ; Tooth* ; Vertical Dimension*

PURPOSE: This study was conducted to evaluate clinical validity of a zirconia full-coverage crown by comparing zirconia's wear capacity over antagonistic teeth with that of feldspathic dental porcelain. MATERIALS AND METHODS: The subject groups were divided into three groups: the polished feldspathic dental porcelain group (Group 1), the polished zirconia group (Group 2), and the polished zirconia with glazing group (Group 3). Twenty specimens were prepared from each group. Each procedure such as plasticity, condensation, and glazing was conducted according to the manufacturer's manual. A wear test was conducted with 240,000 chewing cycles using a dual-axis chewing simulator. The degree of wear of the antagonistic teeth was calculated by measuring the volume loss using a three-dimensional profiling system and ANSUR 3D software. The statistical significance of the measured degree of wear was tested with a significant level of 5% using one-way ANOVA and the Tukey test. RESULTS: The degrees of wear of the antagonistic teeth were 0.119 +/- 0.059 mm3 in Group 1, 0.078 +/- 0.063 mm3 in Group 3, and 0.031 +/- 0.033 mm3 in Group 2. Statistical significance was found between Group 1 and Groups 2 and between Group 2 and 3, whereas no statistical significance was found between Group 1 and Group 3. CONCLUSION: Despite the limitations of this study on the evaluation of antagonistic teeth wear, the degree of antagonistic tooth wear was less in zirconia than feldspathic dental porcelain, representing that the zirconia may be more beneficial in terms of antagonistic tooth wear.
Analysis of Variance ; Ceramics ; Crowns ; Dental Porcelain ; Mastication ; Plastics ; Tooth ; Tooth Wear ; Zirconium