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Rafeie N, Sampaio CS, Hirata R. Transitioning from injectable resin composite restorations to resin composite CAD/CAM veneers: A clinical report. J ESTHET RESTOR DENT 2024; 36:1221-1227. [PMID: 38546152 DOI: 10.1111/jerd.13216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/19/2024] [Accepted: 02/26/2024] [Indexed: 08/11/2024]
Abstract
OBJECTIVE To describe a shift from injectable resin composite technique to composite resin computer-aided design and computer-aided manufacturing (CAD/CAM) veneers in addressing esthetic concerns associated with diastemas between anterior lower teeth in a clinical case. CLINICAL CONSIDERATIONS Among several techniques proposed for direct resin composite restoration, the "Injectable resin composite technique" has gained popularity for its time-efficiency, reduced technique sensitivity, and diminished reliance on clinician skills. However, challenges such as staining and the need for frequent polishing follow-ups may prompt the consideration of more stable alternatives such as indirect veneer restorations. While ceramic veneers offer superior mechanical and optical properties, resin ceramic veneers, especially those milled from CAD/CAM resin ceramic blocks, offer advantages such as rapid, cost-effective production, simplified intra-oral repairs, less susceptibility to fracture, superior stress absorption, and requires minimal tooth preparation, making them an appealing option for many patients. Moreover, a fully-digital approach not only streamlines the process but also saves time and labor while ensuring the delivery of high-quality restorations to patients. CONCLUSION In addressing a patient's dissatisfaction with constant polishing of direct resin composite restorations, a shift to resin composite CAD/CAM veneers was implemented. Utilizing a fully-digital approach with CAD/CAM resin ceramic restorations successfully restored both esthetics and function. CLINICAL SIGNIFICANCE While the injectable resin composite technique achieves immediate esthetic results, its low color stability necessitates frequent polishing sessions. The replacement of direct resin composite restorations with CAD/CAM resin composite veneers becomes a viable option for patients seeking more stable restorations that require fewer follow-ups. This transition addresses both esthetic concerns and the need for enduring solutions in restorative dentistry.
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Affiliation(s)
- Niyousha Rafeie
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, USA
| | - Camila S Sampaio
- Advanced Clinical Fellowship Program in Operative and Digital Dentistry; and APA Advanced Clinical Fellowship Program in Esthetic Dentistry, New York University College of Dentistry, New York, USA
| | - Ronaldo Hirata
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, USA
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Ilie N. Influence of surface finishing on the outcome of a 3-point bending test in polymer-based dental composits assessed by qualitative and quantitative fractography. J Mech Behav Biomed Mater 2024; 156:106607. [PMID: 38830315 DOI: 10.1016/j.jmbbm.2024.106607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/24/2024] [Accepted: 05/29/2024] [Indexed: 06/05/2024]
Abstract
OBJECTIVES The aim of the study was to evaluate the influence of surface finishing in three polymer-based composits (composits) on the result of a 3-point bending test using quantitative and qualitative fractography as well as microstructural characteristics. MATERIALS AND METHODS 270 rectangular specimens (n = 30) of three composits were prepared, stored and tested according to NIST No. 4877. Prior testing, the samples were subjected to three surface treatments: 1) no treatment, to preserve the oxygen inhibition layer, 2) with FEPA P1200 (ANSI equivalent grit 600) SiC paper abraded surface, and 3) polished surface. A three-point bending testing was employed, followed by quantitative (assessment of reason for failure and fracture pattern) and qualitative (fracture mirror measurements) fractography, 3D and 2D surface imaging, surface roughness, reliability and Fe-SEM analysis. The mirror radius that runs in the direction of constant stress was used to calculate the mirror constant (A) using Orr's equation. Uni- and multifactorial ANOVA, Tukey's post hoc test, and Weibull analysis was performed for statistical analysis. RESULTS Surface finishing has less influence on the fracture pattern, reliability and mechanical parameters and has no influence on the mirror constant. The amount of inorganic filler has a direct impact on flexural strength and modulus, while the ranking of materials was independent of surface treatment. Failures initiated by volume defects were the most common failure mode (77.0%) with surface defects accounting for 14.9% (edge) and 7.7% (corner). Polishing resulted in lower peak-to valley height compared to no treatment, both 3-4 times lower compared to the 600 grit treatment. The increase in roughness within the analyzed range did not lead to an increase in surface-related failures. CONCLUSIONS The clear dominance of volume defects in all examined materials as a cause of material fracture reduces the impact of roughness on the measured properties. This insight was only possible using qualitative and quantitative research fractography.
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Affiliation(s)
- Nicoleta Ilie
- Department of Conservative Dentistry, University Hospital, Ludwig-Maximilians-University, Goethestr. 70, D-80336, Munich, Germany.
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Kim JH, Kwon JS, Park JM, Lo Russo L, Shim JS. Effects of postpolymerization conditions on the physical properties, cytotoxicity, and dimensional accuracy of a 3D printed dental restorative material. J Prosthet Dent 2024; 132:241-250. [PMID: 35778292 DOI: 10.1016/j.prosdent.2022.04.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 10/17/2022]
Abstract
STATEMENT OF PROBLEM Although the introduction of high-speed 3-dimensional (3D) printing technology has significantly reduced printing time, the time required for postpolymerization is a speed-determining step because of the long wait time. How postpolymerization conditions affect material properties is unclear. PURPOSE The purpose of this in vitro study was to assess the physical properties, accuracy, and biosafety of a 3D printed dental restorative material according to postpolymerization conditions. MATERIAL AND METHODS Specimens were prepared by 3D printing with a digital light processing 3D printer with 1 interim dental material (C&B MFH). All printed specimens underwent a postpolymerization process with 5 different postpolymerization devices and were designated as groups D1 (D102H), FO (Form Cure), LC (LC-3DPrintBox), ME (Medusa), and MP (MP100). The light intensity and temperature of each device were measured, and the Vickers hardness, flexural strength and modulus, degree of conversion (DC), cytotoxicity, and polymerization shrinkage were analyzed. Statistical analyses were conducted with 1-way analysis of variance, the Tukey post hoc test, and regression testing (α=.05). Scanning electron microscopy was used to assess the fracture surface characteristics of the specimens. RESULTS Light intensity was strongest with the ME device, and the temperature inside the device during postpolymerization showed the highest increase with the LC device and the lowest increase with the D1 device. The LC group specimens showed the highest mean Vickers hardness, and the MP group showed the lowest. The flexural strength was ≥100 MPa in all groups, with a flexural modulus ranging from 1.17 to 1.5 GPa. The DC results were similar to the physical properties test results. The D1, FO, LC, and ME groups all showed ≥70% cell viability, indicating no toxicity. The FO group showed the highest shrinkage rate of 0.52%. CONCLUSIONS When the light intensity was strong, the surface was sufficiently hard, and toxic substances were not eluted even after a short postpolymerization time, suggesting that light intensity modulation and time management can be used to improve the postpolymerization process.
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Affiliation(s)
- Jang-Hyun Kim
- Postgraduate student, Department and Research Institute of Dental Biomaterials and Bioengineering, Oral Research Science Center, BK21 FOUR Project, Yonsei University College of Dentistry, Seoul, Republic of Korea; Researcher, Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Jae-Sung Kwon
- Assistant Professor, Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Ji-Man Park
- Associate Professor, Department of Prosthodontics & Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
| | - Lucio Lo Russo
- Associate Professor, Department of Clinical and Experimental Medicine, School of Dentistry, University of Foggia, Foggia, Italy
| | - June-Sung Shim
- Professor, Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Republic of Korea
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Alharbi G, Al Nahedh HNA, Al-Saud LM, Shono N, Maawadh A. Flexural strength and degree of conversion of universal single shade resin-based composites. Heliyon 2024; 10:e32557. [PMID: 38961985 PMCID: PMC11219500 DOI: 10.1016/j.heliyon.2024.e32557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 05/13/2024] [Accepted: 06/05/2024] [Indexed: 07/05/2024] Open
Abstract
Background/purpose Recently, a group of universal single-shade resin-based composites (RBCs) has been developed to simplify the process of shade selection. Excellent mechanical and physical properties are crucial for the ultimate success and clinical longevity of restorations. Therefore, evaluating the properties of the single-shaded RBCs is imperative. This study aimed to determine the flexural strength (FS) and degree of conversion (DC) of universal single-shade RBCs. Materials and methods In this study, four commercial RBCs were used; three universal single-shade RBCs; Omnichroma (OC), Charisma® Diamond ONE (CD), and Vittra APS Unique (VU), and a conventional nanohybrid composite Filtek™ Z250 XT (FT) which was used as a control. Sixty composite beams and 40 composite discs were used for FS and DC, respectively. A universal test machine with a three-point bending test was used to measure the FS, whereas the DC was measured using a Fourier-transform infrared spectrometer (FTIR). Three fractured specimens from each resin composite group were qualitatively analyzed using scanning electron microscopy. Results ANOVA was used to compare the mean values of FS and DC among the four RBCs (OC, CD, VU, and FT). Highly significant differences were observed in the mean FS and DC values (F = 673.043, p < 0.001 and F (=782.4, p < 0.0001), respectively. The highest FS was observed in the CD group, followed by FT and VU groups; the lowest value was observed in the OC group. In addition, a statistically significant difference was identified in DC values. The highest DC value was observed in VU, followed by OC and CD, and the lowest DC value was observed in FT. Conclusion Universal single-shade RBCs demonstrated a good FS, except for OC, which exhibited a significantly low FS. The DC of the universal single-shade RBCs was higher than that of the conventional nanohybrid composite restorative material.
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Affiliation(s)
- Ghada Alharbi
- Department of Restorative Dental Science, College of Dentistry, King Saud University. P.O. Box 60169, Riyadh 11545, Saudi Arabia
- Department of Clinical Dental Sciences, College of Dentistry, Princess Nourah Bint Abdulrahman University. PO Box 84428, Riyadh 11671, Saudi Arabia
| | - Hend NA Al Nahedh
- Department of Restorative Dental Science, College of Dentistry, King Saud University. P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - Loulwa M. Al-Saud
- Department of Restorative Dental Science, College of Dentistry, King Saud University. P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - Nourah Shono
- Department of Restorative Dental Science, College of Dentistry, King Saud University. P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - Ahmed Maawadh
- Department of Restorative Dental Science, College of Dentistry, King Saud University. P.O. Box 60169, Riyadh 11545, Saudi Arabia
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Espinar C, Pérez MM, Pulgar R, Leon-Cecilla A, López-López MT, Della Bona A. Influence of printing orientation on mechanical properties of aged 3D-printed restorative resins. Dent Mater 2024; 40:756-763. [PMID: 38429216 DOI: 10.1016/j.dental.2024.02.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 02/15/2024] [Accepted: 02/18/2024] [Indexed: 03/03/2024]
Abstract
OBJECTIVE To evaluate the influence of printing orientation on flexural strength (σf) and elastic modulus (E) of different 3D printing dental restorative resins. METHODS Bar-shaped specimens (n = 20) were fabricated from two SLA-printed resins (FT- Formlabs Temporary, and FP- Formlabs Permanent) and two DLP-printed resins (DFT- Detax Freeprint Temp, and GCT- GC Temporary) using two building orientations (0º and 90º). The 3D-printed structures were aged (14 d) before submitted to three-point bending in 37ºC distilled water at a crosshead speed of 1.0 ± 0.3 mm/min until fracture to calculate the σf and the E values. The fractured surfaces were evaluated using stereomicroscopy and scanning electron microscopy (SEM) following fractography principles. Data were statistically analyzed using two-way ANOVA and Tukey post-hoc (α = 0.001). RESULTS FP and FT showed significantly higher E values than DFT and GCT, irrespectively of printing orientation (p < 0.001). There was no statistical difference between the building orientations (0º and 90º) for the mean σf and E values for the resin materials evaluated. Fractographic characteristics were similar for the surface fracture from all the materials evaluated, showing typical brittle fracture behavior. SIGNIFICANCE Printing orientation did not influence of flexural strength and elastic modulus values for the 3D-printed resin structures evaluated. Surface topography was mostly governed by the 3D printer type.
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Affiliation(s)
- Cristina Espinar
- Department of Stomatology, Faculty of Dentistry, Colegio Máximo, Campus de Cartuja s/n. University of Granada, 18071 Granada, Spain
| | - María M Pérez
- Department of Optics, Faculty of Science, Campus Fuentenueva, Edificio Mecenas, s/n. University of Granada, 18071 Granada, Spain
| | - Rosa Pulgar
- Department of Stomatology, Faculty of Dentistry, Colegio Máximo, Campus de Cartuja s/n. University of Granada, 18071 Granada, Spain
| | - Alberto Leon-Cecilla
- Department of Applied physics, Faculty of Science, Campus Fuentenueva, University of Granada, 18071 Granada, Spain
| | - Modesto T López-López
- Department of Applied physics, Faculty of Science, Campus Fuentenueva, University of Granada, 18071 Granada, Spain
| | - Alvaro Della Bona
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Campus I, Passo Fundo, RS, Brazil.
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Ilie N. Shade, Aging and Spatial-Dependent Variation of Elastoplastic and Viscoelastic Characteristics in a Dental, Submicron Hybrid CAD/CAM Composite. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5654. [PMID: 37629945 PMCID: PMC10456770 DOI: 10.3390/ma16165654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/09/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023]
Abstract
This article reports the elastoplastic and viscoelastic response of an industrially cured CAD/CAM resin-based composite (Brilliant Crios, Coltene) at different scales, spatial locations, aging conditions, and shading. Mechanical tests were performed at the macroscopic scale to investigate material strength, elastic modulus, fracture mechanisms and reliability. An instrumented indentation test (IIT) was performed at the microscopic level in a quasi-static mode to assess the elastic and plastic deformation upon indentation, either by mapping transverse areas of the CAD/CAM block or at randomly selected locations. A dynamic-mechanical analysis was then carried out, in which chewing-relevant frequencies were included (0.5 to 5 Hz). Characteristics measured at the nano- and micro-scale were more discriminative in identifying the impact of variables as those measured at macro scale. Anisotropy as a function of the spatial location was identified in all shades, with gradual variation in properties from the center of the block to peripheral locations. Depending on the scale of observation, differences in shade and translucency are very small or not statistically significant. The aging effect is classified as low, but measurable on all scales, with the same pattern of variation occurring in all shades. Aging affects plastic deformation more than elastic deformation and affects elastic deformation more than viscous deformation.
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Affiliation(s)
- Nicoleta Ilie
- Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität in Munich, Goethestr. 70, D-80336 Munich, Germany
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Ghelbere R, Ilie N. Validation of the Orr theory in dental resin-based composites: A fractographic approach. J Mech Behav Biomed Mater 2023; 144:105982. [PMID: 37352623 DOI: 10.1016/j.jmbbm.2023.105982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/14/2023] [Accepted: 06/17/2023] [Indexed: 06/25/2023]
Abstract
OBJECTIVES The present study aimed to assess the applicability of Orr's equation on light-cured resin-based composites (RBCs) tested in 3- and 4-point bending tests, as well as assess the operator reliability of this method. METHODS Fracture mirrors of 320 specimens (n = 320) made of four RBCs that had failed in the two tests were analyzed microscopically and consequently two radii of each specimen were measured by two operators, each measuring twice. The mirror constant A was calculated using Orr's equation. The results of the two operators were compared using a t-Test and further assessment of the data was performed using a MANOVA, Tukey's post hoc test and regression analysis. RESULTS With the exception of 11 specimens, the measurement of the fracture mirror radii was carried out successfully. The calculation of the mirror constant proved successful with a high coefficient of determination (R2 > 0.98). The calculated mirror constants were operator-independent if the results of more than one measurement was taken into consideration. The ratio of the mirror constant A to the fracture toughness KIc lay between 2.1 and 2.4 for three of the four RBC. The fourth RBC had a ratio of 1.6 and was the only one where different mirror constants were observed as a function of the testing method. SIGNIFICANCE The present study proves the applicability of brittle fracture mechanics on RBCs despite them often being regarded as not brittle due to their also plastic behavior.
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Affiliation(s)
- Raluca Ghelbere
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU, Germany
| | - Nicoleta Ilie
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU, Germany.
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Daabash R, Alshabib A, Alqahtani MQ, Price RB, Silikas N, Alshaafi MM. Ion releasing direct restorative materials: Key mechanical properties and wear. Dent Mater 2022; 38:1866-1877. [DOI: 10.1016/j.dental.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/18/2022] [Accepted: 09/22/2022] [Indexed: 11/15/2022]
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Bergamo ETP, Campos TMB, Piza MMT, Gutierrez E, Lopes ACO, Witek L, Coelho PG, Celestrino M, Carvalho LFD, Benalcázar Jalkh EB, Bonfante EA. Temporary materials used in prosthodontics: The effect of composition, fabrication mode, and aging on mechanical properties. J Mech Behav Biomed Mater 2022; 133:105333. [PMID: 35839630 DOI: 10.1016/j.jmbbm.2022.105333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 06/19/2022] [Accepted: 06/20/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the effect of composition, fabrication mode, and thermal cycling on the mechanical properties of different polymeric systems used for temporary dental prostheses. MATERIALS AND METHODS Standard bar-shaped specimens (25 × 2 × 2 mm) were fabricated of six polymeric systems of varying compositions and fabrication modes (n = 10/group): conventional PMMA (Alike, GC) - group CGC; conventional PMMA (Dêncor, Clássico) - group CD; bis-acryl (Tempsmart, GC) - group BGC; bis-acryl (Yprov, Yller) - group BY; milled PMMA (TelioCAD, Ivoclar) - group MI; 3D printed bis-acryl - (Cosmos Temp, Yller) group PY. Half of the specimens were subjected to 5000 thermal cycles (5 °C to 55 °C). Three-point bending tests were performed using a universal testing machine with a crosshead speed set to 0.5 mm/min. Flexural strength and elastic modulus were calculated from the collected data. FTIR spectra were recorded pre and post curing and after thermal cycling to evaluate material composition and degree of conversion. Energy-dispersive spectroscopy (EDS) and scanning electron microscope (SEM) were utilized to examine the composition and micromorphology of the systems, respectively. Data were analyzed using two-analysis of variance and Tukey tests (α = 0.05). RESULTS FTIR spectra indicated that BGC, BY and PY groups corresponded to urethane dimethacrylate systems (bis-acryl), while CGC, CD, and MI groups corresponded to monomethacrylate systems, polymethyl methacrylate (PMMA). Bis-acryl BGC system yeilded the highest flexural strength (80 MPa), followed by the milled PMMA MI system (71 MPa), both statistically significant different relative to other groups. Bis-acryl BY exhibited the lowest flexural strength (27 MPa). Thermocycling significantly increased the flexural strength of all polymeric systems (∼10-15 MPa), except for the 3D-printed PY group. Bis-acryl BGC (1.89 GPa) and conventional PMMA CGC (1.66 GPa) groups exhibited the highest elastic modulus, followed by milled PMMA MI group (1.51 GPa) and conventional PMMA CD (1.45 GPa) systems, with significant difference detected between BGC group and MI and CD groups. The 3D printed PY (0.78 GPa) and bis-acryl BY (0.47 GPa) systems presented the lowest elastic modulus. Thermocycling did not have a significant influence on the elastic modulus. FTIR spectra indicate water sorption and release of unreacted monomers as well as increased degree of conversion (∼5-12%) after thermal cycling. CONCLUSION Composition and fabrication mode and thermal cycling significantly affected the mechanical properties of polymeric systems used for temporary dental prostheses.
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Affiliation(s)
- Edmara T P Bergamo
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil; Division of Biomaterials, Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, USA.
| | - Tiago M B Campos
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Mariana M T Piza
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Eliezer Gutierrez
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Adolfo C O Lopes
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Lukasz Witek
- Division of Biomaterials, Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, USA; Department of Biomedical Engineering, New York University Tandon School of Engineering, Brooklyn, NY, USA
| | - Paulo G Coelho
- Division of Biomaterials, Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY, USA; Hansjörg Wyss Department of Plastic Surgery, NYU Langone Medical Center, New York, NY, USA; Department of Mechanical and Aerospace Engineering, New York University Tandon School of Engineering, Brooklyn, NY, USA
| | | | - Laura F de Carvalho
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Ernesto B Benalcázar Jalkh
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
| | - Estevam A Bonfante
- Department of Prosthodontics and Periodontology, University of Sao Paulo, Bauru School of Dentistry, Bauru, Brazil
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Prediction of uniaxial and biaxial flexural strengths of resin-based composites using the Weibull model. J Mech Behav Biomed Mater 2022; 131:105231. [DOI: 10.1016/j.jmbbm.2022.105231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/04/2022] [Accepted: 04/09/2022] [Indexed: 11/21/2022]
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Novel Polymerization of Dental Composites Using Near-Infrared-Induced Internal Upconversion Blue Luminescence. Polymers (Basel) 2021; 13:polym13244304. [PMID: 34960853 PMCID: PMC8704827 DOI: 10.3390/polym13244304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 11/17/2022] Open
Abstract
Blue light (BL) curing on dental resin composites results in gradient polymerization. By incorporating upconversion phosphors (UP) in resin composites, near-infrared (NIR) irradiation may activate internal blue emission and a polymerization reaction. This study was aimed to evaluate the competency of the NIR-to-BL upconversion luminance in polymerizing dental composites and to assess the appropriate UP content and curing protocol. NaYF4 (Yb3+/Tm3+ co-doped) powder exhibiting 476-nm blue emission under 980-nm NIR was adapted and ball-milled for 4–8 h to obtain different particles. The bare particles were assessed for their emission intensities, and also added into a base composite Z100 (3M EPSE) to evaluate their ability in enhancing polymerization under NIR irradiation. Experimental composites were prepared by dispensing the selected powder and Z100 at different ratios (0, 5, 10 wt% UP). These composites were irradiated under different protocols (BL, NIR, or their combinations), and the microhardness at the irradiated surface and different depths were determined. The results showed that unground UP (d50 = 1.9 μm) exhibited the highest luminescence, while the incorporation of 0.4-μm particles obtained the highest microhardness. The combined 20-s BL and 20–120-s NIR significantly increased the microhardness on the surface and internal depths compared to BL correspondents. The 5% UP effectively enhanced the microhardness under 80-s NIR irradiation but was surpassed by 10% UP with longer NIR irradiation. The combined BL-NIR curing could be an effective approach to polymerize dental composites, while the intensity of upconversion luminescence was related to specific UP particle size and content. Incorporation of 5–10% UP facilitates NIR upconversion polymerization on dental composites.
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Graf N, Ilie N. Long-term mechanical stability and light transmission characteristics of one shade resin-based composites. J Dent 2021; 116:103915. [PMID: 34871633 DOI: 10.1016/j.jdent.2021.103915] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The study aims to investigate the long-term mechanical characteristics, reliability, and light transmission of novel, one shade resin-based composites (RBC). METHODS 120 Specimens (n = 20) of three RBCs (Venus Diamond/VD, Venus Pearl/VP, Omnichroma/OC) were used in a three-point bending test, to determine flexural modulus (E) and flexural strength (σ). Testing ensued after 24 h or thermocycling (TC/10,000 cycles, 5/55 °C). Each fracture mechanism and filler system were documented, using light and scanning electron microscopy. A depth-sensing indentation test (n = 6) quantified the indentation modulus (Y), Martens/Vickers hardness (HM, HV) and creep (Cr). Incident (I0) and transmitted irradiance (IT) plus radiant exposure (RET) per RBC were measured employing a USB4000 spectrometer (n = 3) to calculate spectral absorbance. Data was tested for significant differences (α = 0.05) utilizing Student's t-tests, one- and multiple-way analysis of variance (ANOVA) and Tukey's post-hoc tests along with Pearson's correlational and Weibull analysis. RESULTS Initially, σ, E and Weibull modulus m were the highest for VP. After TC σ was comparable for VP and VD, E was higher for VD and m higher for VP. Maximum Y, HM, HV and Cr were always measured for VD. Inferior parameters, except Cr, were always recorded for OC. IT, RET and absorbance differed marginally, with OC on top. CONCLUSIONS The variation in long-term mechanical stability and light transmission is significantly dependent on RBC formulation, most notably due to filler system and resin matrix. CLINICAL SIGNIFICANCE One shade RBCs vary substantially in their material composition and characteristics, facilitating the diversity present in RBC direct restoratives.
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Affiliation(s)
- Niklas Graf
- Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University, LMU Munich Goethestr. 70, 80336 Munich, Germany.
| | - Nicoleta Ilie
- Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University, LMU Munich Goethestr. 70, 80336 Munich, Germany.
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Comparison of Mechanical Properties of Chairside CAD/CAM Restorations Fabricated Using a Standardization Method. MATERIALS 2021; 14:ma14113115. [PMID: 34204092 PMCID: PMC8200951 DOI: 10.3390/ma14113115] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 11/18/2022]
Abstract
The aim of this in vitro study was to investigate the fracture resistance, fracture failure pattern, and fractography of four types of chairside computer-aided design/computer-aided manufacturing (CAD/CAM) restoration materials in teeth and titanium abutments fabricated using a standardization method. An artificial mandibular left first premolar prepared for all-ceramic crown restoration was scanned. Forty extracted mandibular molars and cylindrical titanium specimens were milled into a standardized shape. A total of eighty CAD/CAM restoration blocks were milled into a crown and twenty pieces of each lithium disilicate (LS), polymer-infiltrated-ceramic-network (PICN), resin nano ceramic (RNC), and zirconia-reinforced lithium silicate (ZLS) materials were used. Crowns were bonded to abutments, and all specimens underwent thermal cycling treatment for 10,000 cycles. Fracture resistance was measured using a universal testing machine and fracture failure patterns were analyzed using optical microscopy and scanning electron microscopy. Statistical differences were analyzed using appropriate ANOVA, Tukey HSD post hoc tests, and independent sample t-tests (α = 0.05). The results indicated that, in both teeth abutments and titanium abutments, the fracture resistances showed significantly the highest values in LS and the second highest in ZLS (p < 0.05). The fracture resistances based on teeth abutments and titanium abutments were significantly different in all the CAD/CAM restoration materials (p < 0.05). There are statistically significant correlations between the types of materials and the types of abutments (p < 0.05). Each of the different materials showed different fracture failure patterns, and there was no noticeable difference in fractographic analysis. Lithium disilicates and zirconia-reinforced lithium silicates exhibited statistically high fracture resistance, indicating their suitability as restoration materials for natural teeth or implant abutments. There were no distinct differences in the fracture pattern based on the restoration and abutment materials showed that the fracture initiated at the groove where the ball indenter was toughed and propagated toward the axial wall.
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Saratti CM, Rocca GT, Durual S, Lohbauer U, Ferracane JL, Scherrer SS. Fractography of clinical failures of indirect resin composite endocrown and overlay restorations. Dent Mater 2021; 37:e341-e359. [DOI: 10.1016/j.dental.2021.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/28/2021] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
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15
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Quantitative and qualitative analyses of ceramic chipping. J Mech Behav Biomed Mater 2020; 110:103928. [DOI: 10.1016/j.jmbbm.2020.103928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/06/2020] [Accepted: 06/09/2020] [Indexed: 11/23/2022]
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Abdulhameed N, Angus B, Wanamaker J, Mecholsky JJ. Quantitative fractography as a novel approach to measure fracture toughness of direct resin composites. J Mech Behav Biomed Mater 2020; 109:103857. [PMID: 32543417 DOI: 10.1016/j.jmbbm.2020.103857] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/07/2020] [Accepted: 05/10/2020] [Indexed: 11/29/2022]
Abstract
Dental resin composites generally fail from small cracks. Large crack techniques are not representative of in vivo failures. Quantitative fractography relies on the observation of small "natural flaws". This study investigates the effect of flaws that occur from fabrication and handling on the measurement of fracture toughness for four different direct resin composites. Microtensile dog-bone shaped specimens for each of four composites were fractured to measure the strength. In addition, we measured crack sizes of the fracture initiating cracks and determined the fracture toughness from these measurements using quantitative fractographic analysis on selected specimens. The characteristic strengths (28-51 MPa) and Weibull moduli (4.9-7.8) were also determined and related to the toughness values (0.5-0.9 MPa m1/2) obtained. The elastic moduli (5-10 GPa) were measured using an indentation technique that has not been used before for direct resin composites. The indentation technique offers an alternative method for small specimens. Quantitative fractographic analysis offers a useful technique to assess fracture toughness of resin composites from cracks of the same size as observed in practice. The toughness of the direct resin composites results from a balance between the size, number and shape of filler particles and the viscosity of the resin matrix.
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Affiliation(s)
- Nader Abdulhameed
- Materials Science and Engineering Department, Herbert Wertheim College of Engineering, University of Florida, USA; LECOM School of Dental Medicine, Florida, USA.
| | - Brendan Angus
- Materials Science and Engineering Department, Herbert Wertheim College of Engineering, University of Florida, USA
| | - Jack Wanamaker
- Materials Science and Engineering Department, Herbert Wertheim College of Engineering, University of Florida, USA
| | - John J Mecholsky
- Materials Science and Engineering Department, Herbert Wertheim College of Engineering, University of Florida, USA
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LASSILA L, OKSANEN V, FRÁTER M, VALLITTU PK, GAROUSHI S. The influence of resin composite with high fiber aspect ratio on fracture resistance of severely damaged bovine incisors. Dent Mater J 2020; 39:381-388. [DOI: 10.4012/dmj.2019-051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Lippo LASSILA
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC Institute of Dentistry, University of Turku
| | - Viivi OKSANEN
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC Institute of Dentistry, University of Turku
| | - Márk FRÁTER
- Department of Operative and Esthetic Dentistry, Faculty of Dentistry, University of Szeged
| | - Pekka K. VALLITTU
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC Institute of Dentistry, University of Turku
- City of Turku Welfare Division, Oral Health Care
| | - Sufyan GAROUSHI
- Department of Biomaterials Science and Turku Clinical Biomaterials Center-TCBC Institute of Dentistry, University of Turku
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Brandeburski SBN, Vidal ML, Collares K, Zhang Y, Della Bona A. Edge chipping test in dentistry: A comprehensive review. Dent Mater 2020; 36:e74-e84. [PMID: 32001022 PMCID: PMC7042093 DOI: 10.1016/j.dental.2020.01.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 12/01/2019] [Accepted: 01/14/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Literature on edge chipping test applied to dental materials and structures has been systematically reviewed with regard to the evaluation methods and parameters used. DATA A systematic search of the literature retrieved 3484 relevant studies. After removing duplicates, 1848 records were screened by titles and abstracts and 1797 were excluded; 51 papers were assessed full text for eligibility. Twenty papers were included in this study and they were organized according to the dental materials and structures tested as follows: 2 studies on human tooth, 9 on dental ceramics, 5 on polymer-based composites, and 4 studies evaluated both ceramic and polymer-based materials. SOURCES MEDLINE/PubMed, Scopus and Web of Science databases were searched up to June 2019 without restriction on date and language. STUDY SELECTION In vitro studies using edge chipping test on dental materials and structures were included. CONCLUSIONS Different methods have been used for edge chipping test, regardless of reported parameters. There is significant evidence that edge chipping test is a relevant approach to predict chipping behavior of dental materials and tooth tissues because chips produced from most edge chipping studies are similar to clinically reported chipping failures.
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Affiliation(s)
| | - Marina Lermenn Vidal
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil
| | - Kaue Collares
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil
| | - Yu Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, USA
| | - Alvaro Della Bona
- Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
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20
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Dartora G, Rocha Pereira GK, Varella de Carvalho R, Zucuni CP, Valandro LF, Cesar PF, Caldas RA, Bacchi A. Comparison of endocrowns made of lithium disilicate glass-ceramic or polymer-infiltrated ceramic networks and direct composite resin restorations: fatigue performance and stress distribution. J Mech Behav Biomed Mater 2019; 100:103401. [PMID: 31445400 DOI: 10.1016/j.jmbbm.2019.103401] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/14/2019] [Accepted: 08/19/2019] [Indexed: 11/15/2022]
Abstract
This study compared the fatigue performance and the stress distribution of endodontically treated molars restored with endocrowns obtained with lithium disilicate glass-ceramic or a polymer-infiltrated ceramic network, both processed by CAD-CAM, and direct composite restorations. Forty-eight human mandibular molars were randomly assigned into 03 groups (n = 16) and restored with endocrowns (LD - lithium disilicate glass-ceramic or PICN - polymer-infiltrated ceramic network) or with direct composite restorations. Fatigue testing followed a step-stress approach (initial maximum load of 200 N and 5000 cycles, incremental step load of 200N and 10,000 cycles/step, being the specimens loaded until failure or to a maximum of 135,000 cycles at 2800 N). The fatigue failure load and number of cycles until failure were recorded and statistically analyzed. Fractographic and finite element (FEA) analyzes were conducted as well. There were no differences in fatigue failure load, number of cycles until fracture and mean survival probabilities among groups. However, indirect endocrowns had higher mechanical structural reliability, and LD restorations lasted more time before start to failing. FEA showed that the stress concentration in tooth tissues was higher for the resin composite, followed by PICN and LD in a decreasing order. Almost all fractures were restricted to the restorative material (without tooth involvement), and origins were identified at occlusal surface. The type of restoration did not influence the fatigue failure load, number of cycles until fracture and mean survival probabilities of the restorative strategies. Despite that, the mechanical structural reliability of endocrowns, especially those made of lithium disilicate, was higher and lasted more time before start to failing.
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Affiliation(s)
- Gustavo Dartora
- MSciD Post-Graduate Program in Dentistry, Meridional Faculty, IMED, Passo Fundo, Brazil.
| | | | | | - Camila Pauleski Zucuni
- MSciD and PhD Post-Graduate Program in Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
| | - Paulo Francisco Cesar
- Department of Biomaterials and Oral Biology, University of São Paulo, USP, São Paulo, Brazil.
| | | | - Atais Bacchi
- MSciD Post-Graduate Program in Dentistry, Meridional Faculty, IMED, Passo Fundo, Brazil.
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21
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Chai H, Wang X, Sun J. Miniature specimens for fracture toughness evaluation of dental resin composites. Dent Mater 2019; 35:283-291. [DOI: 10.1016/j.dental.2018.11.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/08/2018] [Accepted: 11/15/2018] [Indexed: 01/30/2023]
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22
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Alvanforoush N, Wong R, Burrow M, Palamara J. Fracture toughness of glass ionomers measured with two different methods. J Mech Behav Biomed Mater 2019; 90:208-216. [DOI: 10.1016/j.jmbbm.2018.09.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/12/2018] [Accepted: 09/17/2018] [Indexed: 10/28/2022]
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23
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Klauer E, Belli R, Petschelt A, Lohbauer U. Mechanical and hydrolytic degradation of an Ormocer®-based Bis-GMA-free resin composite. Clin Oral Investig 2018; 23:2113-2121. [PMID: 30267276 DOI: 10.1007/s00784-018-2651-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 09/20/2018] [Indexed: 01/26/2023]
Abstract
OBJECTIVES The aim of the study was to evaluate the mechanical stability of bisphenol A-glycidyl methacrylate (Bis-GMA) and Ormocer-based resin composites before and after water absorption and to examine water saturation. MATERIAL AND METHODS Disc-shaped specimens of the Bis-GMA (Grandio SO, Voco) and the Ormocer-based (Admira Fusion, Voco) dental resin composites were produced, stored in water, and weighed after pre-determined times to measure the absorbed water. Bend bars were produced and stored for 24 h in dry conditions as well as in distilled water for 14 days or 60 days at 37 °C. The initial flexural strength (FS) under quasi-static loading and flexural fatigue strength (FFS) under cyclic loading were determined under 4-point bending. Fracture toughness (KIc) of both composites was measured using the single-edge-V-notch-beam (SEVNB) technique after the same storage conditions under 3-point bending. RESULTS Within the first 14 days, storage conditions did not affect the initial FS of Grandio SO, while a significant drop in initial FS was observed for Admira Fusion after 2 weeks in water and most of the water was absorbed within this time. FFS for the Bis-GMA composite was not reduced before 2 months in water, whereas for the Ormocer®-based composite, there has been a significant decrease in strength after cyclic fatigue already at 2 weeks of water storage. KIc of Admira Fusion decreased significantly after both storage periods, while KIc of Grandio SO decreased only significantly after 2 weeks of water storage. CONCLUSION All mechanical properties of the Bis-GMA composite were superior to those of the Ormocer®-based material, except water sorption. CLINICAL SIGNIFICANCE Water storage seems to have a much more pronounced effect on the mechanical properties of Ormocer®-based dental composites in comparison to Bis-GMA-based composites.
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Affiliation(s)
- Elena Klauer
- Zahnklinik 1 - Tahnerhaltung und Parodontologie, Forchungslabor für dentale Biomaterialien, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054, Erlangen, Germany
| | - Renan Belli
- Zahnklinik 1 - Tahnerhaltung und Parodontologie, Forchungslabor für dentale Biomaterialien, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054, Erlangen, Germany.
| | - Anselm Petschelt
- Zahnklinik 1 - Tahnerhaltung und Parodontologie, Forchungslabor für dentale Biomaterialien, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054, Erlangen, Germany
| | - Ulrich Lohbauer
- Zahnklinik 1 - Tahnerhaltung und Parodontologie, Forchungslabor für dentale Biomaterialien, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Glueckstrasse 11, 91054, Erlangen, Germany
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YAMAGUCHI S, MEHDAWI IM, SAKAI T, ABE T, INOUE S, IMAZATO S. In vitro/ in silico investigation of failure criteria to predict flexural strength of composite resins. Dent Mater J 2018; 37:152-156. [DOI: 10.4012/dmj.2017-084] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Satoshi YAMAGUCHI
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry
| | - Idris Mohamed MEHDAWI
- Department of Conservative Dentistry and Endodontics, University of Benghazi Faculty of Dentistry
| | - Takahiko SAKAI
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry
| | - Tomohiro ABE
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry
| | - Sayuri INOUE
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry
- Department of Orthodontics and Dentofacial Orthopedics, Osaka University Graduate School of Dentistry
| | - Satoshi IMAZATO
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry
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25
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Hussain B, Thieu MKL, Johnsen GF, Reseland JE, Haugen HJ. Can CAD/CAM resin blocks be considered as substitute for conventional resins? Dent Mater 2017; 33:1362-1370. [DOI: 10.1016/j.dental.2017.09.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 08/09/2017] [Accepted: 09/02/2017] [Indexed: 10/18/2022]
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26
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Ilie N, Hilton TJ, Heintze SD, Hickel R, Watts DC, Silikas N, Stansbury JW, Cadenaro M, Ferracane JL. Academy of Dental Materials guidance-Resin composites: Part I-Mechanical properties. Dent Mater 2017; 33:880-894. [PMID: 28577893 DOI: 10.1016/j.dental.2017.04.013] [Citation(s) in RCA: 172] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE The objective of this project, which was initiated from the Academy of Dental Materials, was to review and critically appraise methods to determine fracture, deformation and wear resistance of dental resin composites, in an attempt to provide guidance for investigators endeavoring to study these properties for these materials. METHODS Test methods have been ranked in the priority of the specific property being tested, as well as of the specific test methods for evaluating that property. Focus was placed on the tests that are considered to be of the highest priority in terms of being the most useful, applicable, supported by the literature, and which show a correlation with clinical findings. Others are mentioned briefly for the purpose of being inclusive. When a standard test method exists, including those used in other fields, these have been identified in the beginning of each section. Also, some examples from the resin composite literature are included for each test method. RESULTS The properties for evaluating resin composites were ranked in the priority of measurement as following: (1) Strength, Elastic Modulus, Fracture toughness, Fatigue, Indentation Hardness, Wear-abrasion (third body) and Wear-attrition (contact/two body), (2) Toughness, Edge strength (chipping) and (3) Wear determined by toothbrush. SIGNIFICANCE The following guidance is meant to aid the researcher in choosing the proper method to assess key properties of dental resin composites with regard to their fracture, deformation and wear resistance.
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Affiliation(s)
- N Ilie
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany.
| | - T J Hilton
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - S D Heintze
- Ivoclar Vivadent AG, Research & Development, Schaan, Liechtenstein
| | - R Hickel
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - D C Watts
- Biomaterials Science Research Group, School of Dentistry, University of Manchester, Manchester, UK; Photon Science Institute, University of Manchester, Manchester, UK
| | - N Silikas
- Biomaterials Science Research Group, School of Dentistry, University of Manchester, Manchester, UK
| | - J W Stansbury
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, CO, USA; Department of Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - M Cadenaro
- Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - J L Ferracane
- Division of Biomaterials & Biomechanics, Oregon Health & Science University, Portland, OR, USA
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Abstract
This study investigated the effect of cross-sectional areas on interfacial fracture toughness and bond strength of bilayered dental ceramics. Zirconia core ceramics were veneered and cut to produce specimens with three different cross-sectional areas. Additionally, monolithic specimens of glass veneer were also prepared. The specimens were tested in tension until fracture at the interface and reported as bond strength. Fracture surfaces were observed, and the apparent interfacial toughness was determined from critical crack size and failure stress. The results showed that cross-sectional area had no effect on the interfacial toughness whereas such factor had a significant effect on interfacial bond strength. The study revealed that cross-sectional area had no effect on the interfacial toughness, but had a significant effect on interfacial bond strength. The interfacial toughness may be a more reliable indicator for interfacial bond quality than interfacial bond strength.
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Affiliation(s)
- Chuchai Anunmana
- Department of Prosthodontics, Faculty of Dentistry, Mahidol University
| | - Wiroj Wansom
- Department of Prosthodontics, Faculty of Dentistry, Mahidol University
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28
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Fatigue behavior of resin-modified monolithic CAD–CAM RNC crowns and endocrowns. Dent Mater 2016; 32:e338-e350. [DOI: 10.1016/j.dental.2016.09.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 07/19/2016] [Accepted: 09/03/2016] [Indexed: 11/18/2022]
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Li J, Cui BC, Lin YH, Deng XL, Li M, Nan CW. High strength and toughness in chromatic polymer-infiltrated zirconia ceramics. Dent Mater 2016; 32:1555-1563. [PMID: 27671468 DOI: 10.1016/j.dental.2016.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/22/2016] [Accepted: 09/03/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the microstructure and mechanical behavior of polymer-infiltrated zirconia ceramics as a function of Fe2O3 concentration (0-0.3mol%). METHODS Polymer-infiltrated zirconia ceramics with different concentrations of Fe2O3 were prepared by infiltration and polymerization. XRD was employed to determine phase structure. The microstructure and fracture mechanism was observed by SEM. Flexural strength and fracture toughness were measured by three-point bending method and single-edge-notched beam method, respectively. Data were analyzed by Weibull distribution. A nanoindentation system was employed to determine elastic modulus and hardness. RESULTS With increasing content of Fe2O3, the flexural strength, fracture toughness, elastic modulus and hardness are all greatly enhanced and the chromatic behavior also improves significantly. As a tradeoff made between strength and elastic modulus, specimen containing 0.2mol% Fe2O3 is found to be the better one, with flexural strength and fracture toughness values being 336.8MPa and 3.91MPam1/2, respectively. Moreover, it maintains a relatively low elastic modulus of 88.2GPa and a moderate hardness of 4.8GPa, close to those of natural enamel. SIGNIFICANCE This polymer-infiltrated zirconia ceramic material is a dental material of biomimetic chromatic and mechanical properties.
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Affiliation(s)
- Jing Li
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China.
| | - Ben-Cang Cui
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China
| | - Yuan-Hua Lin
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China
| | - Xu-Liang Deng
- School & Hospital of Stomatology, Department of Geriatric Dentistry, Peking University, Beijing 100081, PR China
| | - Ming Li
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China
| | - Ce-Wen Nan
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China
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30
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Elsaka SE, Elnaghy AM. Mechanical properties of zirconia reinforced lithium silicate glass-ceramic. Dent Mater 2016; 32:908-14. [DOI: 10.1016/j.dental.2016.03.013] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/10/2015] [Accepted: 03/22/2016] [Indexed: 11/27/2022]
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31
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Campos F, Almeida CS, Rippe MP, de Melo RM, Valandro LF, Bottino MA. Resin Bonding to a Hybrid Ceramic: Effects of Surface Treatments and Aging. Oper Dent 2016; 41:171-8. [DOI: 10.2341/15-057-l] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
The aim of this study was to verify the effects of different surface treatments on the microtensile bond strength between resin cement and a hybrid ceramic. Thirty-two hybrid ceramic slices (8 × 10 × 3 mm) were produced and allocated among four groups according to the surface treatment: Cont = no treatment, HA = 10% hydrofluoric acid applied for 60 seconds, PA = 37% phosphoric acid applied for 60 seconds and CJ = air abrasion with silica particle coated alumina (Cojet Sand, 3M ESPE, 30 μm/2.8 bar). As a control group, eight blocks of feldspathic ceramic (8 × 10 × 3 mm) were etched by hydrofluoric acid for 60 seconds (VMII). After the surface treatments, the ceramic slices were silanized (except the Cont group) and adhesively cemented to composite resin blocks (8 × 10 × 3 mm ) with a load of 750 g (polymerized for 40 seconds each side). The cemented blocks were cut into beams (bonded surface area of ∼1 mm2). Half of the beams were aged (thermocycling of 5°C-55°C/6000 cycles + water storage at 37°C/60 days), and the other half were tested immediately after being cut. Data were analyzed by Kruskal-Wallis and Dunn tests (non-aged groups) and by one-way analysis of variance and Tukey test (aged groups; α=0.05%). The mode of failure was classified by stereomicroscopy. The surface treatment significantly affected the bond strength in each set of groups: non-aged (p=0.001) and aged (p=0.001). Before being aged, samples in the CJ, HA, and PA groups achieved the highest bond strength values. However, after being aged, only those in the HA group remained with the highest bond strength values. Adhesive failure was found most often. In conclusion, hydrofluoric acid etching should be used for surface conditioning of the studied hybrid ceramic.
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Affiliation(s)
- F Campos
- Fernanda Campos, DDS, MSc, PhD Student in Prosthodontics, Univ Estadual Paulista (UNESP), Institute of Science and Technology, São José dos Campos Dental School, Department of Dental Materials and Prosthodontics, São José dos Campos, SP, Brazil
| | - CS Almeida
- Carolina Souza Almeida, DDS, MSc, Univ Estadual Paulista (UNESP), Institute of Science and Technology, São José dos Campos Dental School, Department of Dental Materials and Prosthodontics, São José dos Campos, SP, Brazil
| | - MP Rippe
- Marilia Pivetta Rippe, DDS, MSc, PhD, Restorative Dentistry (Prosthodontics), Federal University of Santa Maria, Santa Maria, RS,, Brazil
| | - RM de Melo
- Renata Marques de Melo, DDS, MSc, PhD, Univ Estadual Paulista (UNESP), Institute of Science and Technology, São José dos Campos Dental School, Department of Dental Materials and Prosthodontics, São José dos Campos, SP, Brazil
| | - LF Valandro
- Luiz Felipe Valandro, DDS, MSc, PhD, Restorative Dentistry (Prosthodontics), Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - MA Bottino
- Marco Antonio Bottino, DDS, PhD, Univ Estadual Paulista (UNESP), Institute of Science and Technology, São José dos Campos Dental School, Department of Dental Materials and Prosthodontics, São José dos Campos, SP, Brazil
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Abstract
The degree of interplay among variables in dental implant treatment presents a challenge to randomized clinical trials attempting to answer questions in a timely, unbiased, and economically feasible fashion. Further adding complexity to the different scenarios is the varied implant designs and related bone response, area of implantation, implant bulk material, restoration, abutments and related screws, fixation mode (screwed, fixed, or a combination), and horizontal implant-abutment matching geometry. This article critically appraises the most common mechanical testing methods used to characterize the implant-prostheses complex. It attempts to provide insight into the process of construction of an informed database of clinically relevant questions regarding preclinical evaluation of implant biomechanics and failure mechanisms. The use of single load to failure, fatigue life, fatigue limit, and step-stress accelerated life testing is discussed with emphasis on their deliverables, weaknesses, and strengths. Fractographic analysis and challenges in the correlation between laboratory- and in-service-produced failures of dental ceramics, resin composites, and titanium are introduced. In addition, examples are presented of mechanical characterization studies used in our laboratory to assess some implant-supported rehabilitation variables.
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Abstract
Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials.
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Affiliation(s)
- N D Ruse
- Biomaterials, Faculty of Dentistry, University of British Columbia, 2199 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - M J Sadoun
- Unité de Recherches Biomatériaux Innovants et Interfaces (URB2I-EA4462), Faculté de chirurgie dentaire, Université Paris Descartes, Sorbonne Paris Cité, 1 rue Maurice Arnoux, 92120 Montrouge, France
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Quinn GD. On edge chipping testing and some personal perspectives on the state of the art of mechanical testing. Dent Mater 2014; 31:26-36. [PMID: 25244927 DOI: 10.1016/j.dental.2014.08.378] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 08/19/2014] [Accepted: 08/28/2014] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The edge chipping test is used to measure the fracture resistance of dental restoration ceramics and resin composites. This paper focuses on the progress of evaluating chipping resistance of these materials and also on the progress of standardization of this test method. This paper also makes observations about the state of the art of mechanical testing of ceramic and composite restorative materials in general. Interlaboratory comparative studies ("round robins") are recommended. METHODS An edge chipping machine was used to evaluate dozens of materials including porcelains, glass ceramics, aluminas, zirconias, filled resin-composites, new hybrid ceramic-resin composites, laminated composite ceramics, and even polymethyl methacrylate based denture materials. Force versus distance data was collected over a broad range with different indenters. Several chipping resistance parameters were quantified. RESULTS Older restorative materials such as feldspathic porcelains and veneering materials had limited chipping resistance, but more modern ceramics and filled composites show significant improvements. A yttria-partially stabilized zirconia had the greatest resistance to chipping. Much of the early work on edge chipping resistance of brittle materials emphasized linear force versus distance trends obtained with relatively blunt Rockwell C indenters. More recently, trends for dental restorative materials with alternative sharper indenters have been nonlinear. A new phenomenological model with a simple quadratic function fits all data exceptionally well. It is loosely based on an energy balance between indenter work and fracture and deformation energies in the chipped material. SIGNIFICANCE Although a direct comparison of our laboratory scale tests on idealized simple geometries to clinical outcomes has not yet been done, anecdotal evidence suggests the procedure does produce clinically relevant rankings and outcomes. Despite the variations in the trends and indenters, comparisons between materials can easily be made by chipping convenient block-shaped specimens with sharp conical 120°, Vickers, or Rockwell C indenters at a defined edge distance of 0.5mm. Broad distance ranges are recommended for trend evaluation. This work has provided important information for standardization.
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Affiliation(s)
- G D Quinn
- Materials Measurement Science Division, Stop 852-9, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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Quinn GD, Giuseppetti AA, Hoffman KH. Chipping fracture resistance of denture tooth materials. Dent Mater 2014; 30:545-53. [PMID: 24674342 PMCID: PMC4084649 DOI: 10.1016/j.dental.2014.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/23/2014] [Accepted: 02/13/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The applicability of the edge chipping method to denture tooth materials was assessed. These are softer materials than those usually tested by edge chipping. The edge chipping fracture resistances of polymethylmethacrylate (PMMA) based and two filled resin composite denture tooth materials were compared. METHODS An edge chipping machine was used to chip rectangular blocks and flattened anterior denture teeth. Force versus edge distance data were collected over a broad range of forces and distances. Between 20 and 65 chips were made per condition depending upon the material, the scatter, and the indenter type. Different indenter types were used including Rockwell C, sharp conical 120(o), Knoop, and Vickers. The edge toughness, Te, was evaluated for different indenter types. RESULTS The edge chipping data collected on the blocks matched the data collected from flattened teeth. High scatter, particularly at large distances and loads, meant that many tests (up to 64) were necessary to compare the denture tooth materials and to ascertain the appropriate data trends. A linear force-distance trend analysis was adequate for comparing these materials. A power law trend might be more appropriate, but the large scatter obscured the definitive determination of the precise trend. Different indenters produce different linear trends, with the ranking of: sharp conical 120(o), Rockwell C, and Knoop, from lowest to highest edge toughness. Vickers indenter data were extremely scattered and a sensible trend could not be obtained. Edge toughness was inversely correlated to hardness. SIGNIFICANCE Edge chipping data collected either from simple laboratory scale test blocks or from actual denture teeth may be used to evaluate denture materials. The edge chipping method's applicability has been extended to another class of restorative materials.
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Affiliation(s)
- G D Quinn
- Paffenbarger Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA.
| | - A A Giuseppetti
- Paffenbarger Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA
| | - K H Hoffman
- Paffenbarger Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA
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Belli R, Petschelt A, Lohbauer U. Are linear elastic material properties relevant predictors of the cyclic fatigue resistance of dental resin composites? Dent Mater 2014; 30:381-91. [DOI: 10.1016/j.dental.2014.01.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 08/30/2013] [Accepted: 01/14/2014] [Indexed: 11/17/2022]
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Quinn GD, Giuseppetti AA, Hoffman KH. Chipping fracture resistance of dental CAD/CAM restorative materials: part 2. Phenomenological model and the effect of indenter type. Dent Mater 2014; 30:e112-23. [PMID: 24685179 DOI: 10.1016/j.dental.2014.02.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 02/13/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED The edge chipping resistances of six CAD/CAM dental restoration materials are analyzed and correlated to other mechanical properties. A new quadratic relationship that is based on a phenomenological model is presented. OBJECTIVE The purpose of this study was to further analyze the edge chipping resistance of the brittle materials evaluated in Part 1. One objective was to determine why some force-distance trends were linear and others were nonlinear. A second objective was to account for differences in chipping resistance with indenter type. METHODS Edge chipping experiments were conducted with different indenters, including some custom-made sharp conical indenters. A new force - distance quadratic expression was correlated to the data and compared to the linear and power law trends. RESULTS The new quadratic function was an excellent fit in every instance. It can account for why some materials can be fit by a linear trend, while others can be fit by the power law trend. The effects of indenter type are accounted for variations in crack initiation and by the wedging stresses once an indentation hole is created. SIGNIFICANCE The new quadratic force - edge distance function can be used with edge chipping data for all brittle materials, not just those evaluated in this study. The data trends vary from linear to nonlinear depending upon the material's hardness, fracture toughness, and elastic modulus.
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Affiliation(s)
- G D Quinn
- Volpe Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, United States.
| | - A A Giuseppetti
- Volpe Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, United States
| | - K H Hoffman
- Volpe Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, United States
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Quinn GD, Giuseppetti AA, Hoffman KH. Chipping fracture resistance of dental CAD/CAM restorative materials: part I--procedures and results. Dent Mater 2014; 30:e99-e111. [PMID: 24685178 DOI: 10.1016/j.dental.2014.02.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The edge chipping test was used to measure the fracture resistance of CAD/CAM dental restoration ceramics and resin composites. METHODS An edge chipping machine was used to evaluate six materials including one feldspathic porcelain, two glass ceramics, a filled resin-composite, a yttria-stabilized zirconia, and a new ceramic-resin composite material. Force versus edge distance data were collected over a broad range of forces and distances. Data were analyzed by several approaches and several chipping resistance parameters were evaluated. The effects of using different indenter types were explored. RESULTS The force versus distance trends were usually nonlinear with good fits to a power law equation with exponents usually ranging from 1.2 to 1.9. The order of chipping resistance (from least to greatest) was: feldspathic porcelain and a leucite glass ceramic (which were similar), followed by the lithium disilicate glass ceramic and the two resin composites (which were similar), and finally the zirconia which had the greatest resistance to chipping. Chipping with a Vickers indenter required 28-45% more force than with the sharp conical 120° indenter. The two indenters rank materials approximately the same way. The power law exponents were very similar for the two indenters for a particular material, but the exponents varied with material. The Rockwell C indenter gives different power law trends and rankings. SIGNIFICANCE Despite the variations in the trends and indenters, simple comparisons between materials can be made by chipping with sharp conical 120° or Vickers indenters at 0.50mm. Broad distance ranges are recommended for trend evaluation.
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Affiliation(s)
- G D Quinn
- Volpe Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA.
| | - A A Giuseppetti
- Volpe Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA
| | - K H Hoffman
- Volpe Research Center, American Dental Association Foundation, Stop 854-6, NIST, Gaithersburg, MD 29899, USA
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Della Bona A, Corazza PH, Zhang Y. Characterization of a polymer-infiltrated ceramic-network material. Dent Mater 2014; 30:564-9. [PMID: 24656471 DOI: 10.1016/j.dental.2014.02.019] [Citation(s) in RCA: 195] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/15/2014] [Accepted: 02/20/2014] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To characterize the microstructure and determine some mechanical properties of a polymer-infiltrated ceramic-network (PICN) material (Vita Enamic, Vita Zahnfabrik) available for CAD-CAM systems. METHODS Specimens were fabricated to perform quantitative and qualitative analyses of the material's microstructure and to determine the fracture toughness (KIc), density (ρ), Poisson's ratio (ν) and Young's modulus (E). KIc was determined using V-notched specimens and the short beam toughness method, where bar-shaped specimens were notched and 3-point loaded to fracture. ρ was calculated using Archimedes principle, and ν and E were measured using an ultrasonic thickness gauge with a combination of a pulse generator and an oscilloscope. RESULTS Microstructural analyses showed a ceramic- and a polymer-based interpenetrating network. Mean and standard deviation values for the properties evaluated were: KIc=1.09±0.05MPam(1/2), ρ=2.09±0.01g/cm(3), ν=0.23±0.002 and E=37.95±0.34GPa. SIGNIFICANCE The PICN material showed mechanical properties between porcelains and resin-based composites, reflecting its microstructural components.
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Affiliation(s)
- Alvaro Della Bona
- Post-graduation Program in Dentistry, Dental School, University of Passo Fundo, Passo Fundo, RS, Brazil.
| | - Pedro H Corazza
- Department of Dental Materials and Prosthodontics, Institute of Science and Technology of São José dos Campos, São Paulo State University (UNESP), São José dos Campos, SP, Brazil
| | - Yu Zhang
- Department of Biomaterials & Biomimetics, College of Dentistry, New York University, New York, NY, USA
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SILVA EA, TRINDADE FZ, RESKALLA HNJF, de QUEIROZ JRC. Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis. J Appl Oral Sci 2013; 21:335-40. [PMID: 24037072 PMCID: PMC3881885 DOI: 10.1590/1678-775720130012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/14/2013] [Accepted: 06/04/2013] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. MATERIAL AND METHODS Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05). RESULTS The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces. CONCLUSION Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are a more effective strategy.
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Affiliation(s)
- Emilia Adriane SILVA
- DDS, MSc, Department of Restorative Dentistry, Federal University of
Juiz de Fora, Juiz de Fora, MG, Brazil
| | - Flávia Zardo TRINDADE
- DDS, MSc, PhD, Department of Implantology, School of Dentistry,
University of Santo Amaro, SP, Brazil
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Lohbauer U, Belli R, Ferracane J. Factors Involved in Mechanical Fatigue Degradation of Dental Resin Composites. J Dent Res 2013; 92:584-91. [DOI: 10.1177/0022034513490734] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The design of clinical trials allows for limited insights into the fatigue processes occurring in resin composites and the factors involved therein. In vitro studies, in contrast, can fundamentally narrow study interests to focus on particular degradation mechanisms and, to date, represent the major contributors to the state of knowledge on the subject. These studies show that microstructural features are important in determining strength and fracture toughness, whereas fatigue resistance is mainly related to the susceptibility of the matrix and the filler/matrix interface to mechanical and chemical degradation. In this review, we focus on fracture mechanisms occurring during fatigue, on the methods used to assess them, and on additional phenomena involved in the degradation of initial mechanical properties of resin composites.
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Affiliation(s)
- U. Lohbauer
- Laboratory for Biomaterials Research, Dental Clinic 1 – Operative Dentistry and Periodontology, University of Erlangen-Nuremberg, Glueckstrasse 11, 91054 Erlangen, Germany
| | - R. Belli
- Laboratory for Biomaterials Research, Dental Clinic 1 – Operative Dentistry and Periodontology, University of Erlangen-Nuremberg, Glueckstrasse 11, 91054 Erlangen, Germany
| | - J.L. Ferracane
- Division of Biomaterials & Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR 97239, USA
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Nguyen JF, Migonney V, Ruse ND, Sadoun M. Properties of experimental urethane dimethacrylate-based dental resin composite blocks obtained via thermo-polymerization under high pressure. Dent Mater 2013; 29:535-41. [DOI: 10.1016/j.dental.2013.02.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 02/15/2013] [Accepted: 02/18/2013] [Indexed: 11/30/2022]
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Coldea A, Swain MV, Thiel N. Mechanical properties of polymer-infiltrated-ceramic-network materials. Dent Mater 2013; 29:419-26. [PMID: 23410552 DOI: 10.1016/j.dental.2013.01.002] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 01/17/2013] [Accepted: 01/21/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To determine and identify correlations between flexural strength, strain at failure, elastic modulus and hardness versus ceramic network densities of a range of novel polymer-infiltrated-ceramic-network (PICN) materials. METHODS Four ceramic network densities ranging from 59% to 72% of theoretical density, resin infiltrated PICN as well as pure polymer and dense ceramic cross-sections were subjected to Vickers Indentations (HV 5) for hardness evaluation. The flexural strength and elastic modulus were measured using three-point-bending. The fracture response of PICNs was determined for cracks induced by Vickers-indentation. Optical and scanning electron microscopy (SEM) was employed to observe the indented areas. RESULTS Depending on the density of the porous ceramic the flexural strength of PICNs ranged from 131 to 160MPa, the hardness values ranged between 1.05 and 2.10GPa and the elastic modulus between 16.4 and 28.1GPa. SEM observations of the indentation induced cracks indicate that the polymer network causes greater crack deflection than the dense ceramic material. The results were compared with simple analytical expressions for property variation of two phase composite materials. SIGNIFICANCE This study points out the correlation between ceramic network density, elastic modulus and hardness of PICNs. These materials are considered to more closely imitate natural tooth properties compared with existing dental restorative materials.
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Affiliation(s)
- Andrea Coldea
- Department of Oral Sciences, School of Dentistry, Dunedin 9001, New Zealand.
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44
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Petersen RC. Accurate Critical Stress Intensity Factor Griffith Crack Theory Measurements by Numerical Techniques. SAMPE JOURNAL. SOCIETY FOR THE ADVANCEMENT OF MATERIAL AND PROCESS ENGINEERING 2013; 2013:737-752. [PMID: 25620817 PMCID: PMC4302413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Critical stress intensity factor (KIc) has been an approximation for fracture toughness using only load-cell measurements. However, artificial man-made cracks several orders of magnitude longer and wider than natural flaws have required a correction factor term (Y) that can be up to about 3 times the recorded experimental value [1-3]. In fact, over 30 years ago a National Academy of Sciences advisory board stated that empirical KIc testing was of serious concern and further requested that an accurate bulk fracture toughness method be found [4]. Now that fracture toughness can be calculated accurately by numerical integration from the load/deflection curve as resilience, work of fracture (WOF) and strain energy release (SIc) [5, 6], KIc appears to be unnecessary. However, the large body of previous KIc experimental test results found in the literature offer the opportunity for continued meta analysis with other more practical and accurate fracture toughness results using energy methods and numerical integration. Therefore, KIc is derived from the classical Griffith Crack Theory [6] to include SIc as a more accurate term for strain energy release rate (𝒢Ic), along with crack surface energy (γ), crack length (a), modulus (E), applied stress (σ), Y, crack-tip plastic zone defect region (rp) and yield strength (σys) that can all be determined from load and deflection data. Polymer matrix discontinuous quartz fiber-reinforced composites to accentuate toughness differences were prepared for flexural mechanical testing comprising of 3 mm fibers at different volume percentages from 0-54.0 vol% and at 28.2 vol% with different fiber lengths from 0.0-6.0 mm. Results provided a new correction factor and regression analyses between several numerical integration fracture toughness test methods to support KIc results. Further, bulk KIc accurate experimental values are compared with empirical test results found in literature. Also, several fracture toughness mechanisms are discussed especially for fiber-reinforced composites.
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45
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SILVA EA, TRINDADE FZ, RESKALLA HNJF, de QUEIROZ JRC. Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis. J Appl Oral Sci 2013. [PMID: 24037072 PMCID: PMC3881885 DOI: 10.1590/1679-775720130012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. MATERIAL AND METHODS Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05). RESULTS The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces. CONCLUSION Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are a more effective strategy.
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Affiliation(s)
- Emilia Adriane SILVA
- DDS, MSc, Department of Restorative Dentistry, Federal University of
Juiz de Fora, Juiz de Fora, MG, Brazil
| | - Flávia Zardo TRINDADE
- DDS, MSc, PhD, Department of Implantology, School of Dentistry,
University of Santo Amaro, SP, Brazil
| | | | - José Renato Cavalcanti de QUEIROZ
- DDS, MSc, PhD, Department of Biotechnology, Potiguar University, Natal,
RN, Brazil.,Corresponding address: José Renato Cavalcanti de Queiroz - Av. Gov.
Juvenal Lamartine, 326 (903-II) - Tirol - Natal - RN Brazil - 59.020-280 - Phone: 55
84 99870445 - e-mail:
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The effects of environment and cyclic fatigue on the mechanical properties of an indirect composite. J Dent 2012; 40:787-92. [PMID: 22722058 DOI: 10.1016/j.jdent.2012.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 04/27/2012] [Accepted: 05/25/2012] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES The purpose of this study was to examine the flexure strength (σ) and fracture toughness (K(IC)) of three indirect dental composites (dentin, body, and incisal) with respect to loading (static and cyclic), testing environments (air and water) and ageing (0 (controls) and 6 months in air and water). METHODS The specimens were 3 mm × 3 mm × 25 mm bars with the fracture toughness specimens having a 0.75 mm notch machined in the midspan. Static testing utilized 15 bars and cyclic testing 25 bars for each testing variable. All bars were tested using three-point loading and the cyclic testing was for 1000 cycles using a staircase approach. RESULTS For flexure strength and fracture toughness, all specimen groups showed a decrease in mean values when exposed to cyclic loading as compared to the static loading mean and when exposed to ageing compared to the control specimens. ANOVA analysis demonstrated that dentin specimens had higher flexure strength and fracture toughness means than incisal and body specimens and that control and water specimens had higher flexure strength and fracture toughness means than aged and air specimens. CONCLUSIONS Degradation of these materials, as a result of cyclic loading and ageing in an aqueous environment, appears to be influenced by more than just the processing of the composite.
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Azar MR, Bagheri R, Burrow MF. Effect of storage media and time on the fracture toughness of resin-based luting cements. Aust Dent J 2012; 57:349-54. [PMID: 22924360 DOI: 10.1111/j.1834-7819.2012.01703.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Resin-based cements are brittle materials and the major shortcomings of these materials are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin luting cements have been described, few fracture toughness test data for resin-based luting cements using the short rod design have been published. METHODS Specimens were prepared from five resin luting cements. For each material a total of 36 disc-shaped specimens were prepared using a custom-made mould. Specimens were randomly divided into six groups of six, immersed in two solutions: distilled water and 0.01 mol/L lactic acid at 37 °C for 24 hours, 1 month or 3 months. The specimens were loaded using a universal testing machine. The maximum load at specimen failure was recorded and the K(Ic) (MPa. M 0.5) was calculated. RESULTS There was a relationship between material, storage solution and time (p < 0.05). Nexus 3 showed the highest K(Ic) followed by Panavia F, Calibra, Smart Cem2 and seT. CONCLUSIONS The fracture toughness of the resin luting cements was affected by both time and storage solution. Comparable fracture toughness of conventional resin cement and self-adhesive resin cements was observed.
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Affiliation(s)
- M R Azar
- Department of Endodontics, Faculty of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
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Bonfante EA, Suzuki M, Lubelski W, Thompson VP, de Carvalho RM, Witek L, Coelho PG. Abutment Design for Implant-Supported Indirect Composite Molar Crowns: Reliability and Fractography. J Prosthodont 2012; 21:596-603. [DOI: 10.1111/j.1532-849x.2012.00872.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Tian KV, Nagy PM, Chass GA, Fejerdy P, Nicholson JW, Csizmadia IG, Dobó-Nagy C. Qualitative assessment of microstructure and Hertzian indentation failure in biocompatible glass ionomer cements. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:677-685. [PMID: 22286280 DOI: 10.1007/s10856-012-4553-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 01/11/2012] [Indexed: 05/31/2023]
Abstract
Discs of biocompatible glass ionomer cements were prepared for Hertzian indentation and subsequent fracture analyses. Specifically, 2 × 10 mm samples for reproducing bottom-initiated radial fracture, complemented by 0.2 × 1 mm samples for optimal resolution with X-ray micro tomography (μCT), maintaining dimensional ratio. The latter allowed for accurate determination of volumetric-porosity of the fully cured material, fracture-branching through three Cartesian axes and incomplete bottom-initiated cracking. Nanocomputed tomography analyses supported the reliability of the μCT results. Complementary 2-dimensional fractographic investigation was carried out by optical and scanning electron microscopies on the larger samples, identifying fracture characteristics. The combined 3-D qualitative assessment of microstructure and fractures, complemented by 2-D methods, provided an increased understanding of the mechanism of mechanical failure in these cements. Specifically, cracks grew to link pores while propagating along glass-matrix interfaces. The methodological development herein is exploitable on related biomaterials and represents a new tool for the rational characterisation, optimisation and design of novel materials for clinical service.
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Affiliation(s)
- Kun V Tian
- Materials Science Research Institute, Faculty of Dentistry, Semmelweis University, Budapest, Hungary
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Suzuki M, Bonfante E, Silva NR, Coelho PG. Reliability Testing of Indirect Composites as Single Implant Restorations. J Prosthodont 2011; 20:528-34. [PMID: 22003830 DOI: 10.1111/j.1532-849x.2011.00754.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Marcelo Suzuki
- Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA, USA
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