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S¸ivet Ö, Malkondu Ö, Küçükkurt S, Kazazoglu E. Evaluation of Changes in Temperature of Zirconia Frameworks During Grinding Under Different Chair-Side Conditions: An In Vitro Study. JOURNAL OF ADVANCED ORAL RESEARCH 2020. [DOI: 10.1177/2320206820953947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Aim: To evaluate the changes in the temperature of zirconia during grinding under different clinical conditions. Materials and Methods: A total of 60 zirconia framework specimens were fabricated and divided into groups of 10 specimens each. Two different handpieces, namely, a high-speed handpiece (HSH) and a low-speed handpiece (LSH), were used for grinding with and without water cooling. Fine- and coarse-grit diamond burrs were used with the HSH, separately. The following six groups were created: (a) HSH fine-grit with water cooling, (b) HSH coarse grit with water cooling, (c) HSH fine grit without water cooling, (d) HSH coarse grit without water cooling, (e) LSH with water cooling, and (f) LSH without water cooling. Each zirconia framework was ground until 1 mm3 of the material was removed. Temperature values corresponding to the grinding techniques were compared and statistically analyzed. One-way analysis of variance was used to compare the group parameters, while the Tukey honest significant difference test was used to detect significant differences between the groups. The significance level was set at P <.05. Results: The highest mean temperature was measured in the case of grinding with the LSH without water cooling (54.7 °C ± 11.6 °C), while the lowest mean temperature was observed in the case of grinding with the HSH using the coarse-grit diamond rotary instrument under water cooling (22.6 °C ± 0.6 °C). Conclusions: The grinding of zirconia must be performed with an HSH under water cooling. Further, when water cooling is used, neither the type of handpiece nor the grain type of the rotary instrument used as it has a significant effect on the temperature.
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Affiliation(s)
- Özgecan S¸ivet
- Department of Prosthodontics, Istanbul Aydın University, Istanbul, Turkey
| | - Özlem Malkondu
- Department of Prosthodontics, Yeditepe University, Istanbul, Turkey
| | - Sercan Küçükkurt
- Department of Oral and Maxillofacial Surgery, Istanbul Aydın University, Istanbul, Turkey
| | - Ender Kazazoglu
- Department of Prosthodontics, Yeditepe University, Istanbul, Turkey
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Color and translucency of zirconia infrastructures and porcelain-layered systems. J Prosthet Dent 2019; 121:510-516. [DOI: 10.1016/j.prosdent.2018.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 08/07/2018] [Accepted: 08/07/2018] [Indexed: 11/21/2022]
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Wongkamhaeng K, Dawson DV, Holloway JA, Denry I. Effect of Surface Modification on In-Depth Transformations and Flexural Strength of Zirconia Ceramics. J Prosthodont 2018; 28:e364-e375. [PMID: 29741238 DOI: 10.1111/jopr.12908] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2018] [Indexed: 12/01/2022] Open
Abstract
PURPOSE Chairside surface adjustments of zirconia dental restorations enhance the toughening stress-induced tetragonal-to-monoclinic phase transformation and domain reorientation by ferro-elastic domain switching (FDS), but also trigger subsurface damage, which could compromise long-term clinical performance. The purpose of this study was to assess the depth of phase transformation, associated FDS, and flexural strength of dental zirconia (BruxZir HT 2.0), after chairside surface treatments. MATERIALS AND METHODS Square specimens were sectioned from CAD/CAM blocks and sintered according to manufacturer's recommendations (n = 30). They were left as-sintered (AS; control), air abraded with fine (AAF) or coarse (AAC) alumina particles, ground (G) or ground and polished (GP). Roughness was measured by profilometry. Crystalline phases were investigated by grazing incidence X-ray diffraction (GIXRD) (n = 3). GIXRD data were fit using semi-log regression protocols to assess transformation depth and extent of FDS. The mean biaxial flexural strength was measured according to ISO 6872. Subsurface damage was assessed from SEM images using a bonded polished interface configuration. Flaw distribution was assessed by Weibull analysis. Results were analyzed by Kruskal-Wallis with Tukey's adjustment for multiple comparisons (p < 0.05). RESULTS Air-abraded and ground groups exhibited higher mean surface roughness than control. AAF group exhibited the highest flexural strength (1662.6 ± 202.6 MPa) with flaw size (5.9 ± 1.8 μm) smaller than transformation (14.5 ± 1.2 μm) or FDS depth (19.3 ± 1.1 μm), followed by GP group (1567.2 ± 209.7 MPa) with smallest FDS depth (9.3 ± 2.0 μm) and flaw size (2.6 ± 1.8 μm), but without m-phase. AAC group (1371.4 ± 147.6 MPa) had the largest flaw size (40.3 ± 20.3 μm), transformation depth (47.2 ± 3.0 μm) and FDS depth (41.2 ± 2.2 μm). G group (1357.0 ± 196.7 MPa) had the smallest transformation depth (8.6 ± 1.5 μm), and mean FDS depth (19.8 ± 3.7 μm) and flaw size (18.6 ± 3.1 μm). AAC and AAF exhibited the highest Weibull modulus (11.2 ± 0.4 and 9.8 ± 0.3 μm, respectively). CONCLUSIONS Variations in mean biaxial flexural strength were explained by the balance between the depth of toughening mechanisms (phase transformation and FDS) and subsurface damage. AAF and GP groups were the most efficient surface adjustments in promoting the highest mean biaxial flexural strength.
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Affiliation(s)
- Kan Wongkamhaeng
- Department of Prosthodontics, University of Iowa College of Dentistry, Iowa City, IA.,Iowa Institute for Oral Health Research, University of Iowa College of Dentistry, Iowa City, IA
| | - Deborah V Dawson
- Iowa Institute for Oral Health Research, University of Iowa College of Dentistry, Iowa City, IA.,Division of Biostatistics and Research Design, University of Iowa College of Dentistry, Iowa City, IA
| | - Julie A Holloway
- Department of Prosthodontics, University of Iowa College of Dentistry, Iowa City, IA
| | - Isabelle Denry
- Department of Prosthodontics, University of Iowa College of Dentistry, Iowa City, IA.,Iowa Institute for Oral Health Research, University of Iowa College of Dentistry, Iowa City, IA
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Bakitian F, Seweryniak P, Papia E, Larsson C, Vult von Steyern P. Effect of different semimonolithic designs on fracture resistance and fracture mode of translucent and high-translucent zirconia crowns. Clin Cosmet Investig Dent 2018; 10:51-60. [PMID: 29628778 PMCID: PMC5878660 DOI: 10.2147/ccide.s157118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose The aim of this study was to describe different designs of semimonolithic crowns made of translucent and high-translucent zirconia materials and to evaluate the effect on fracture resistance and fracture mode. Methods One hundred crowns with different designs were produced and divided into five groups (n=20): monolithic (M), partially veneered monolithic (semimonolithic) with 0.3 mm buccal veneer (SM0.3), semimonolithic with 0.5 mm buccal veneer (SM0.5), semimonolithic with 0.5 mm buccal veneer supported by wave design (SMW), and semimonolithic with 0.5 mm buccal veneer supported by occlusal cap design (SMC). Each group was divided into two subgroups (n=10) according to the materials used, translucent and high-translucent zirconia. All crowns underwent artificial aging before loading until fracture. Fracture mode analysis was performed. Fracture loads and fracture modes were analyzed using two-way ANOVA and Fisher's exact probability tests (P≤0.05). Results SM0.3 design showed highest fracture loads with no significant difference compared to M and SMW designs (P>0.05). SM0.5 design showed lower fracture loads compared to SMW and SWC designs. Crowns made of translucent zirconia showed higher fracture loads compared to those made of high-translucent zirconia. M, SM0.3, and all but one of the SMC crowns showed complete fractures with significant differences in fracture mode compared to SMW and SM0.5 crowns with cohesive veneer fractures (P≤0.05). Conclusion Translucent and high-translucent zirconia crowns might be used in combination with 0.3 mm microcoating porcelain layer with semimonolithic design to enhance the esthetic properties of restorations without significantly decreasing fracture resistance of the crowns. If 0.5 mm porcelain layer is needed for a semimonolithic crown, wave design or cap design might be used to increase fracture resistance. In both cases, fracture resistance gained is likely to be clinically sufficient as the registered fracture loads were high in relation to expected loads under clinical use.
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Affiliation(s)
- Fahad Bakitian
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden.,Department of Restorative Dentistry, Faculty of Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia
| | | | - Evaggelia Papia
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Christel Larsson
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - Per Vult von Steyern
- Department of Materials Science and Technology, Faculty of Odontology, Malmö University, Malmö, Sweden
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Nassif W, Rifai M. Surface Characterization and Cell Adhesion of Different Zirconia Treatments: An in vitro Study. J Contemp Dent Pract 2018; 19:181-188. [PMID: 29422468 DOI: 10.5005/jp-journals-10024-2234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM The aim of this study was to characterize the surface of zirconia subjected to different treatments and evaluate its effect on cell adhesion and proliferation. MATERIALS AND METHODS A total of 80 zirconia disks were divided into four groups (n = 20) according to the surface treatments used: group I: as-sintered (AS), no surface treatment applied; group II: abrasion treatment applied using Rocatec (ROC; 3M ESPE) system with silica-coated alumina powder of grit size 110 μm; group III: erbium, chromium:yttrium, scandium, gallium, garnet (Er, Cr:YSGG) laser (LAS; BIOLASE) was used at a frequency of 20 Hz and output power of 3 W; and group IV: specimens were subjected to the selective infiltration etching (SIE) technique. Surface characterization was evaluated for the different groups (roughness, hardness, and morphology), and cell behavior (adhesion and proliferation) was tested (a = 0.05). RESULTS The ROC group reported a significant increase in surface roughness (2.201 ± 0.352) and Vickers hardness (1758 ± 16.6) compared with the other surface treatments. The SIE surface-treated group reported a significantly higher number of cells (64.5 ± 2.6 and 53.5 ± 2.2 respectively) compared with the other surface-treated groups. CONCLUSION The SIE is a promising surface treatment for zirconia that significantly enhances cell adhesion and osseointegration. CLINICAL SIGNIFICANCE The SIE treatment of zirconia implants may help in a faster and better osseointegration.
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Affiliation(s)
- Wadih Nassif
- Department of Prosthodontics, Faculty of Dental Medicine Lebanese University, Beirut, Lebanon, Phone: +9613686787, e-mail:
| | - Mohamad Rifai
- Department of Prosthodontics, Faculty of Dental Medicine Lebanese University, Beirut, Lebanon
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Liu E, Xiao G, Jia W, Shu X, Yang X, Wang Y. Strain-induced phase transformation behavior of stabilized zirconia ceramics studied via nanoindentation. J Mech Behav Biomed Mater 2017; 75:14-19. [DOI: 10.1016/j.jmbbm.2017.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/29/2017] [Accepted: 07/04/2017] [Indexed: 11/25/2022]
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Mohammadi-Bassir M, Babasafari M, Rezvani MB, Jamshidian M. Effect of coarse grinding, overglazing, and 2 polishing systems on the flexural strength, surface roughness, and phase transformation of yttrium-stabilized tetragonal zirconia. J Prosthet Dent 2017; 118:658-665. [PMID: 28385438 DOI: 10.1016/j.prosdent.2016.12.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 11/15/2022]
Abstract
STATEMENT OF PROBLEM Limited information is available for the best polishing systems and methods to obtain minimally abrasive monolithic zirconia surfaces after contouring and occlusal adjustment. PURPOSE The purpose of this in vitro study was to evaluate the effect of grinding and polishing procedures on the flexural strength, quality and quantity of surface roughness, topography, and phase transformation of a zirconia-based ceramic system. MATERIAL AND METHODS Fifty bar-shaped yttrium-stabilized zirconium oxide specimens (20×4×2 mm) were cut from presintered zirconia blanks. The specimens were wet-polished and divided into 5 groups (n=10): standard polishing without any surface treatment (group SP); grinding with a diamond rotary instrument (group Gr); grinding with a diamond rotary instrument (DRI) and over-glazing (group Gl); grinding with a DRI and polishing with an intraoral zirconia polishing kit in a 2-step procedure (group BP); and grinding with a DRI and polishing with an intraoral polishing kit (group MP). The Ra and Rz surface roughness values (μm) were measured with a profilometer. One specimen of each group was subjected to x-ray diffraction (XRD) to estimate the monoclinic phase and evaluated using scanning electron microscopy (SEM) for surface topography. The 3-point flexural strength of the bars was measured in a universal testing machine at a crosshead speed of 0.5 mm/min. The mean flexural strength (MPa) and surface roughness values were calculated, and the results were analyzed using 1-way ANOVA and Tukey honest significant difference tests (α=.05). RESULTS Statistically significant differences were noted among the experimental groups for Ra, Rz (P<.001), and flexural strength values (P<.001). The highest Ra and Rz values were found in group Gr (P<.001) and the lowest in group Gl, which were significantly lower than the values in group Gr (P<.001). The 2 polishing systems (BP and MP) were not significantly different in terms of Ra and Rz values (P=.755 for Ra and P=.319 for Rz). The highest flexural strength was found in group Gr (283.35 ±49.85 MPa) without significant differences from those of MP and BP (P=.958 for BP and P=.404 for MP). The lowest flexural strength was found in Gl, which had no significant differences from those of the control group (P=1.000). In XRD the monoclinic phase was observed in Gr (26%), BP (24%), and MP (23%) groups. However, groups Gl and SP did not have any monoclinic phase. SEM showed deep unidirectional scratches after grinding that were smoothened by glazing and polishing. CONCLUSIONS Roughness increased significantly after grinding, but polishing and glazing similarly diminished it. Glazing after grinding significantly decreased the flexural strength values, but polishing did not.
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Affiliation(s)
- Mahshid Mohammadi-Bassir
- Assistant Professor, Department of Operative Dentistry, School of Dentistry, Shahed University, Tehran, Iran
| | - Mansoure Babasafari
- Resident, Department of Operative Dentistry, School of Dentistry Shahed University, Tehran, Iran
| | - Mohammad Bagher Rezvani
- Assistant Professor, Department of Operative Dentistry, School of Dentistry, Shahed University, Tehran, Iran
| | - Mahdieh Jamshidian
- Assistant Professor, Department of Operative Dentistry, Qom Dental Faculty, Qom University of Medical Sciences, Qom, Iran.
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Sandhu R, Kheur M, Kheur S. Effect of simulated chairside grinding procedures using commercially available abrasive agents on the surface properties of zirconia. J Indian Prosthodont Soc 2017; 17:22-28. [PMID: 28216841 PMCID: PMC5308068 DOI: 10.4103/0972-4052.194938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Aim: The aim of the present study was to assess the change in physical properties (surface roughness, surface hardness and phase transformation) after surface grinding of zirconia by using three commercially available abrasives. Materials and Methods: Thirty sintered zirconia specimens were prepared and divided into three groups namely Group M (grinded using Mani Dia diamond bur standard grit), Group T (grinded using Tri Hawk diamond bur coarse grit) and Group P (grinded using Predator carbide bur). A customised assembly was used to follow a standardised protocol for surface grinding. The surface roughness, surface hardness and phase transformation was recorded before and after the grinding procedure. Statistical Analysis Used: ANOVA and Bonferroni post hoc test were used to assess the values obtained after the testing the surface roughness and surface hardness. Results: The results of the present study revealed the average values of change in surface roughness as Group M (0.44 μm) and Group T (1.235 μm) and Group P (-0.88 μm). The average values of change in surface hardness were Group T (19.578 HV), Group M (46.722 HV) and Group P (36.429 HV). The change in surface hardness was not statistically significant. There was no phase transformation seen after the grinding procedure. Clinical Significance: Carbide burs along with copious water irrigation when used to grind zirconia intra-orally produces has a polishing effect, minimal change in hardness & no phase transformation. The present study advocates the use of carbides for chair-side grinding of zirconia.
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Affiliation(s)
- Ramandeep Sandhu
- Department of Prosthodontics, M. A. Rangoonwala Dental College, Pune, Maharashtra, India
| | - Mohit Kheur
- Department of Prosthodontics, M. A. Rangoonwala Dental College, Pune, Maharashtra, India
| | - Supriya Kheur
- Department of Oral Pathology, DPU University, DY Patil Dental College, Pimpri, Pune, Maharashtra, India
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Guilardi LF, Pereira GKR, Gündel A, Rippe MP, Valandro LF. Surface micro-morphology, phase transformation, and mechanical reliability of ground and aged monolithic zirconia ceramic. J Mech Behav Biomed Mater 2016; 65:849-856. [PMID: 27810731 DOI: 10.1016/j.jmbbm.2016.10.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 10/14/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
Abstract
This study aimed to determine the effects of grinding and low temperature aging on the biaxial flexural strength, structural reliability (Weibull analysis), surface topography, roughness analysis, and phase transformation (t→m) of an yttrium-stabilized tetragonal zirconia polycrystalline ceramic. Ceramic discs (15.0×1.2±0.2mm, VITA In-Ceram YZ) were prepared and randomly assigned into six groups according to 2 factors (n=30): 'grinding' (Ctrl - without treatment, as-sintered; Xfine - grinding with extra fine diamond bur - 30µm; Coarse - grinding by coarse diamond bur - 151µm), and 'aging' (without or with aging: CtrlLTD; XfineLTD; CoarseLTD). Grinding was performed in an oscillatory motion with a contra-angle handpiece under constant water-cooling. Low temperature degradation (LTD) was simulated in an autoclave at 134°C, under 2bar pressure, for 20h. The roughness (Ra and Rz parameters) significantly increased after grinding in accordance with bur grit-size (Coarse>Xfine>Ctrl), and aging promoted distinct effects (Ctrl=CtrlLTD; Xfine>XfineLTD; Coarse=CoarseLTD). Grinding increased the m-phase, and aging led to an increase in the m-phase in all groups. However, different susceptibilities to LTD were observed. Weibull analysis showed a significant increase in the characteristic strength after grinding (Coarse=Xfine>Ctrl), while aging did not lead to any deleterious impact. Neither grinding nor aging resulted in any deleterious impact on material reliability (no statistical decrease in the Weibull moduli). Thus, neither grinding nor aging led to a deleterious effect on the mechanical properties of the evaluated Y-TZP ceramic although a high m-phase content and roughness were observed.
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Affiliation(s)
- L F Guilardi
- MSc-PhD Graduate Program in Oral Science, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - G K R Pereira
- MSc-PhD Graduate Program in Oral Science, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - A Gündel
- Physics School, Federal University of Pampa, Bage, Rio Grande do Sul State, Brazil.
| | - M P Rippe
- MSc-PhD Graduate Program in Oral Science, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
| | - L F Valandro
- MSc-PhD Graduate Program in Oral Science, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil.
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Pereira G, Fraga S, Montagner A, Soares F, Kleverlaan C, Valandro L. The effect of grinding on the mechanical behavior of Y-TZP ceramics: A systematic review and meta-analyses. J Mech Behav Biomed Mater 2016; 63:417-442. [DOI: 10.1016/j.jmbbm.2016.06.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/27/2016] [Accepted: 06/28/2016] [Indexed: 01/09/2023]
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Residual micro-stress distributions in heat-pressed ceramic on zirconia and porcelain-fused to metal systems: Analysis by FIB–DIC ring-core method and correlation with fracture toughness. Dent Mater 2015; 31:1396-405. [DOI: 10.1016/j.dental.2015.08.158] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/09/2015] [Accepted: 08/20/2015] [Indexed: 11/22/2022]
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Preis V, Schmalzbauer M, Bougeard D, Schneider-Feyrer S, Rosentritt M. Surface properties of monolithic zirconia after dental adjustment treatments and in vitro wear simulation. J Dent 2015; 43:133-9. [DOI: 10.1016/j.jdent.2014.08.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/08/2014] [Accepted: 08/15/2014] [Indexed: 10/24/2022] Open
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Effect of heat treatment and in vitro aging on the microstructure and mechanical properties of cold isostatic-pressed zirconia ceramics for dental restorations. Dent Mater 2014; 30:e272-82. [DOI: 10.1016/j.dental.2014.05.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 07/08/2013] [Accepted: 05/21/2014] [Indexed: 02/04/2023]
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14
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Majić Renjo M, Ćurković L, Štefančić S, Ćorić D. Indentation size effect of Y-TZP dental ceramics. Dent Mater 2014; 30:e371-6. [PMID: 25182368 DOI: 10.1016/j.dental.2014.08.367] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 05/30/2014] [Accepted: 08/08/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate and analyze the indentation size effect (ISE) in Vickers hardness of monolithic yttria partially stabilized zirconia (Y-TZP) dental ceramics without and with the addition of dental dye A3. The ISE is analyzed using the Mayer law, a proportional specimen resistance (PSR) model and a modified proportional specimen resistance (MPSR) model. METHODS Two samples of Y-TZP dental ceramics, trade names BruxZir (provided by Glidewell Laboratories, CA, USA), were investigated. The first sample was polished Y-TZP and the second sample was polished Y-TZP with the addition of dental dye A3, by VITA Classical Shade Guide. The Vickers hardness was measured under the following loads: 0.49N, 0.98N, 1.96N, 4.90, 9.81N and 29.42N. Thirty indentations were made on each sample, under each load. Relationships between the applied load, F, and the resulting indentation size, d, have been analyzed by the Mayer law, the PSR model and the MPSR model. RESULTS The Meyer index (n) for both Y-TZP dental ceramics is less than 2, which indicates that hardness is dependent on test loads. The PSR model and the MPSR model were used to calculate "true" Vickers hardness or load-independent hardness. SIGNIFICANCE All applied mathematical models are suitable for the data analysis, which is confirmed with high correlation coefficients, but the best correlation between measured values and mathematical models was achieved with the MPSR model with a correlation coefficient of 0.9999.
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Affiliation(s)
- Marijana Majić Renjo
- Department of materials, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000 Zagreb, Croatia
| | - Lidija Ćurković
- Department of materials, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000 Zagreb, Croatia.
| | | | - Danko Ćorić
- Department of materials, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000 Zagreb, Croatia
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Papia E, Jimbo R, Chrcanovic BR, Andersson M, Vult von Steyern P. Surface structure and mechanical properties of impaction-modified Y-TZP. Dent Mater 2014; 30:808-16. [PMID: 24962988 DOI: 10.1016/j.dental.2014.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
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16
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Karunagaran S, Markose S, Paprocki G, Wicks R. A systematic approach to definitive planning and designing single and multiple unit implant abutments. J Prosthodont 2014; 23:639-48. [PMID: 24916855 DOI: 10.1111/jopr.12161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2013] [Indexed: 11/29/2022] Open
Abstract
With an increase in the availability of implant restorative components, the selection of an appropriate implant abutment for a given clinical situation has become more challenging. This article describes a systematic protocol to help the practitioner more thoughtfully select abutments for single and multiple unit fixed implant prostheses. The article examines the evaluation, planning, design, and fabrication processes for the definitive restoration. It includes an assessment of a variety of factors, namely restorative space, soft and hard tissues, the location of the implant platform, the type of platform connection, platform switching indications, tissue collar heights, emergence profile, implant angulation, and finally the design and esthetic options for the final implant abutment.
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Affiliation(s)
- Sanjay Karunagaran
- Graduate Prosthodontic Resident, Advanced Education Program in Prosthodontics, Department of Prosthodontics, University of Tennessee Health Science Center, Memphis, TN
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Seredin P, Kashkarov V, Lukin A, Ippolitov Y, Julian R, Doyle S. Local study of fissure caries by Fourier transform infrared microscopy and X-ray diffraction using synchrotron radiation. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:705-710. [PMID: 23955033 DOI: 10.1107/s0909049513019444] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 07/14/2013] [Indexed: 06/02/2023]
Abstract
Investigations of intact dental enamel as well as carious-affected human dental enamel were performed using infrared spectromicroscopy and X-ray diffraction applying synchrotron radiation. Caries of enamel was shown to be characterized by an increase in the number of deformation and valence vibrations for N-C-O, N-H and C=O bonds, a decrease of the crystallinity index, and by the absence of the preferable orientation of hydroxyapatite crystals within the affected enamel. This indicates the presence of destructive processes in the organic matrix of hard tooth tissues.
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Affiliation(s)
- Pavel Seredin
- Solid State Physics and Nanostructures, Voronezh State University, Universitetskaya 1, Voronezh 394006, Russian Federation.
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