Wear Behavior of the Human Enamel Antagonist to Different Glazed Zirconia

2020 ◽  
Vol 20 (9) ◽  
pp. 5676-5679
Author(s):  
Su-Kyoung Ryu ◽  
Gye-Jeong Oh ◽  
Jin-Ho Kang ◽  
Jae-Gon Jang ◽  
Kumaresan Sakthiabirami ◽  
...  

In this study, the wear behavior of glazed zirconia was investigated to the antagonist with human enamel after simulated mastication. Twenty Y-TZP specimens were divided into 4 groups: untreated zirconia (Z), glazed zirconia with IPS e.max Ceram (GZE), glazed zirconia with VITA AKZENT® Plus (GZV), and glazed zirconia with glass (GZG). Glazing glass was mainly composed of SiO2, B2O3, Al2O3, Na2O and K2O (nearly 91 wt%). The surface roughness of the specimens was evaluated using roughness profiler. The maxillary premolar teeth were selected as the antagonist. The wear of human enamel against human enamel was used as a control. Five-disc specimens per group were subjected to chewing stimulation CS-4 (SD Mechatronic GmbH, Germany) for 240,000 cycles against human enamel. The wear loss of antagonistic teeth was calculated using a three-dimensional profiling system and the volume loss of the tooth was scanned using a 3D scanner. 3D data obtained before and after testing were overlapped using 3D software (Dentacian Software, EZplant, Korea). The wear loss of glazed zirconia GZE, GZV and GZG groups showed significantly lower than that of human enamel. Whereas, the zirconia (Z) group exhibits significantly lower volume loss than glazed zirconia and enamel. These results show that the wear of the glazing glass is comparable to other commercial glazing materials. Glazing materials are both more susceptible to wear the antagonist relative to zirconia.

2021 ◽  
Vol 11 (1) ◽  
pp. 73-79
Author(s):  
Mohammed Abujalala ◽  
A. Nehir Özden

This study analyzed the wear behavior caused by steatite antagonists to four dental ceramic materials, comparing this between two surface treatments: polishing and glazing. Methods: Thirty flat samples (10 × 8 × 2 mm) were prepared from each of four ceramics: IPS e. max CAD (IPS), GC Initial LiSi Press (LP), Vita Enamic (VE), and monolithic zirconia (MZ). Subgroups of samples were finished by polishing or glazing or neither (as controls). The samples were subjected to computer-controlled chewing simulation (240,000 cycles of 49 N at 1.6 Hz, with thermocycling at 5/55 C), with steatite balls as antagonists. The samples and antagonists were visualized before and after the test with a laser abrasion measurement system, a CAD/CAM scanner, and electron microscopy scanning, and the volumes lost from the tested samples and antagonists were analyzed. Results: For the MZ samples, the polished samples showed significantly less volume loss than the glazed samples (0.0200 mm3 vs. 0.0305 mm3; p =0.0001), whereas there was significantly greater antagonist volume loss (0.0365 mm3 vs. 0.0240 mm3; p = 0.011). There were no significant differences between the subgroups for IPS, VE, and LP, although antagonist volume losses were non-significantly greater with the glazed samples than with the polished samples. Conclusions: Polishing MZ had adverse effects on the corresponding antagonist wear. Glazed MZ showed the lowest antagonist wear.


2019 ◽  
Author(s):  
Mohammed Abujalala ◽  
A.Nehir Özden

Abstract Background: This study analyzed the wear behavior caused by steatite antagonists to four dental ceramic materials, comparing this between two surface treatments: polishing and glazing. Methods: Thirty flat samples (10 × 8 × 2 mm) were prepared from each of four ceramics: IPS e.max CAD (IPS), GC Initial LiSi Press (LP), Vita Enamic (VE), and monolithic zirconia (MZ). Subgroups of samples were finished by polishing or glazing or neither (as controls). The samples were subjected to computer-controlled chewing simulation (240,000 cycles of 49 N at 1.6 Hz, with thermocycling at 5/55°C), with steatite balls as antagonists. The samples and antagonists were visualized before and after the test with a laser abrasion measurement system, a CAD/CAM scanner, and electron microscopy scanning, and the volumes lost from the tested samples and antagonists were analyzed.Results: For the MZ samples, the polished samples showed significantly less volume loss than the glazed samples (0.0200 mm3 vs. 0.0305 mm3; p = 0.0001), whereas there was significantly greater antagonist volume loss (0.0365 mm3 vs. 0.0240 mm3; p = 0.011). There were no significant differences between the subgroups for IPS, VE, and LP, although antagonist volume losses were non-significantly greater with the glazed samples than with the polished samples. Conclusions: Polishing MZ had adverse effects on the corresponding antagonist wear. Glazed MZ showed the lowest antagonist wear.


2016 ◽  
Vol 87 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Thiago Slaviero ◽  
Thais Maria Freire Fernandes ◽  
Paula Vanessa Pedron Oltramari-Navarro ◽  
Ana Claudia de Castro ◽  
Ferreira Conti ◽  
...  

ABSTRACT Objective: To evaluate the dimensional changes of dental arches on digital models of open bite treatment with fixed and removable palatal cribs. Materials and Methods: The sample comprised 41 patients of both sexes who were white, aged 7–10 years, and who had mixed dentition, Angle Class I molar relationship, and a negative overbite of at least 1 mm. The sample was randomly divided into two groups: G1, fixed palatal crib; and G2, removable palatal crib. Cast models, obtained initially (T1) and after 1 year of treatment (T2), were scanned by a three-dimensional (3D) scanner, 3Shape R700, producing a 3D image. Measurements were performed by a calibrated examiner using OrthoAnalyzer™ 3D software. Results: At T2–T1, differences were observed between the groups regarding vertical dentoalveolar development and overjet. There was more mandibular incisor extrusion for G1 (−1.66 mm) than for G2 (−0.54 mm). An overjet increase was observed in G1 (0.56 mm), in contrast to a reduction in G2 (−0.40 mm). There was a similar overbite increase for both groups (3.51 mm for fixed palatal crib and 3.88 mm for removable palatal crib). Conclusions: Both the treatment protocols are similarly effective for anterior open bite correction, providing an overbite increase with dentoalveolar arch changes, especially in the anterior region.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Korehide Arai ◽  
Yuto Tanaka ◽  
Shinsuke Matsuda ◽  
Tomohiko Okamura ◽  
Kazufumi Iwayama ◽  
...  

A 91-year-old woman was referred to our hospital with a chief complaint of unsatisfactory fit and pain associated with her complete dentures. She had moderate dementia with difficulty in communication (Mini-Mental State Examination, 16; Barthel Index, 15). The closed impressions and jaw record were taken with the digitally fabricated copy dentures as follows. First, the tissue conditioner was used to correct the poor fit of the old dentures, following which minor occlusal alterations were made. Second, the copy dentures that copied the morphology of the corrected old dentures using three-dimensional (3D) scanner were fabricated with a 3D printer. The new dentures were then fabricated using conventional methods as follows. The impressions were cast and articulated, and the dentures were subsequently processed. This case report documented the following results. First, the acceptance of new dentures appeared to be easier since the new dentures copied the morphology of the familiar dentures digitally. Moreover, the 3D data of the dentures could be used for immediate denture fabrication in case of fracture or loss of the dentures. Second, only two visits were required for taking an impression and delivering the complete dentures. In addition, her old dentures were brought to our dental office by the patient’s family after the patient’s dinner; immediately after copying the dentures’ morphology, the dentures were returned to the patient’s family, thus avoiding any disturbance to the patient’s eating routine. These reduced the burden on the patient and her family.


2019 ◽  
Vol 30 (5) ◽  
pp. 505-510 ◽  
Author(s):  
João Paulo Mendes Tribst ◽  
Larissa Marcia Marques Alves ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Renata Marques de Melo ◽  
Alexandre Luiz Souto Borges ◽  
...  

Abstract The aim of this study was to investigate the three-dimensional wear, volumetric loss and surface roughness after chewing simulation of two glass ceramics. Lithium disilicate (LD, Emax CAD, Ivoclar) and Zirconia reinforced lithium silicate (ZLS, Vita Suprinity, Vita Zhanfabrick) discs (n=20/g) were scanned to obtain stereolithography (STL) files for each sample. All discs were submitted to chewing simulation with sliding configuration (30 N, 300,000 cycles, 6 mm and 1.7 Hz) with steatite as antagonist. The samples were then scanned again and the volume loss and the deepest defect depth was measured using the superimposed file from the baseline using three-dimensional digital parametric inspection software (GOM Inspect, Braunschweig, Germany). Surface roughness (Ra and Rz) was analyzed with a contact profilometer. Data were analyzed by one-way ANOVA and Tukey test (α=0.5%). ANOVA showed significant differences among the groups. Considering the ceramic volume loss, wear depth defect length and Rz roughness, LD (-22.09±5.57%; 0.80±0.06 µm; 3.08±1.02 µm) showed higher mean values than ZLS (-15.67±4.51%; 0.56±0.09 µm; 1.51±0.90 µm). Ra mean values were similar for both materials (p=0.064). All discs exhibited slight surface scratches along with the sliding direction with pitted wear patterns, while large cracks were observed on wear traces. These same areas can be identified in blue, overlapping the STL files before and after chewing simulation in inspection software. The linear reduction generated by sliding contact shows a graph with a similar wear pattern shape. ZLS was more resistant to wear than LD, with less volume loss and shallower surface defects.


2021 ◽  
Vol 10 (7) ◽  
pp. 460
Author(s):  
Mario Matthys ◽  
Laure De Cock ◽  
John Vermaut ◽  
Nico Van de Weghe ◽  
Philippe De Maeyer

More and more digital 3D city models might evolve into spatiotemporal instruments with time as the 4th dimension. For digitizing the current situation, 3D scanning and photography are suitable tools. The spatial future could be integrated using 3D drawings by public space designers and architects. The digital spatial reconstruction of lost historical environments is more complex, expensive and rarely done. Three-dimensional co-creative digital drawing with citizens’ collaboration could be a solution. In 2016, the City of Ghent (Belgium) launched the “3D city game Ghent” project with time as one of the topics, focusing on the reconstruction of disappeared environments. Ghent inhabitants modelled in open-source 3D software and added animated 3D gamification and Transmedia Storytelling, resulting in a 4D web environment and VR/AR/XR applications. This study analyses this low-cost interdisciplinary 3D co-creative process and offers a framework to enable other cities and municipalities to realise a parallel virtual universe (an animated digital twin bringing the past to life). The result of this co-creation is the start of an “Animated Spatial Time Machine” (AniSTMa), a term that was, to the best of our knowledge, never used before. This research ultimately introduces a conceptual 4D space–time diagram with a relation between the current physical situation and a growing number of 3D animated models over time.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jerzy Montusiewicz ◽  
Marek Miłosz ◽  
Jacek Kęsik ◽  
Kamil Żyła

AbstractHistorical costumes are part of cultural heritage. Unlike architectural monuments, they are very fragile, which exacerbates the problems of their protection and popularisation. A big help in this can be the digitisation of their appearance, preferably using modern techniques of three-dimensional representation (3D). The article presents the results of the search for examples and methodologies of implementing 3D scanning of exhibited historical clothes as well as the attendant problems. From a review of scientific literature it turns out that so far practically no one in the world has made any methodical attempts at scanning historical clothes using structured-light 3D scanners (SLS) and developing an appropriate methodology. The vast majority of methods for creating 3D models of clothes used photogrammetry and 3D modelling software. Therefore, an innovative approach was proposed to the problem of creating 3D models of exhibited historical clothes through their digitalisation by means of a 3D scanner using structural light technology. A proposal for the methodology of this process and concrete examples of its implementation and results are presented. The problems related to the scanning of 3D historical clothes are also described, as well as a proposal how to solve them or minimise their impact. The implementation of the methodology is presented on the example of scanning elements of the Emir of Bukhara's costume (Uzbekistan) from the end of the nineteenth century, consisting of the gown, turban and shoes. Moreover, the way of using 3D models and information technologies to popularise cultural heritage in the space of digital resources is also discussed.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 319
Author(s):  
Zhiguo Lu ◽  
Chuanyu Du ◽  
Qingcai Chen ◽  
Tianying Niu ◽  
Na Wang ◽  
...  

The friction and wear characteristics of spike-tooth material (65Mn steel) of Spike-Tooth Harrow in a two-stage peanut harvester were studied in this paper. The friction and wear tests of pin and disc on 65 manganese steel were carried out on the tribometer, then the wear loss and the friction coefficient were studied. The wear loss of the pin was acquired by calculating the mass of the pin before and after the experiment using an electronic balance. According to the actual working environment of peanut spring-finger, four variable parameters are set up: load, speed, soil moisture and soil type. The friction and wear characteristics of pins were studied under different loads, speeds and different soil environments. After wearing, the worn surface of the material was observed by scanning microscope and the wear mechanism was studied. The experimental results show that the wear of the pin increases with the increase of load and decreases with the increase of rotational speed in the same rotation number. Especially in the case of the sandy soil with 20% in moisture, a maximum wear loss of the pin is achieved.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javier Caviedes-Bucheli ◽  
Nestor Rios-Osorio ◽  
Diana Usme ◽  
Cristian Jimenez ◽  
Adriana Pinzon ◽  
...  

Abstract Background The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. Methods In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student’s t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. Results Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). Conclusion With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.


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