Investigating the Effect of Different Surface Treatments on Vickers Hardness and Flexural Strength of Zirconium and Lithium Disilicate Ceramics

WOS: 000510591400005PubMed: 29961952Purpose To investigate the effect of different surface treatments on Vickers hardness and flexural strength of zirconia and lithium disilicate ceramics. Materials and Methods 50 zirconia and 50 lithium disilicate ceramic specimens were used. After identifying one group as the control, grinding, sandblasting, CoJet, and Er:YAG laser were applied on the surface of specimens (n = 10). After applying Vickers hardness test to specimens, flexural strength test was performed. the data were analyzed with two-way ANOVA and Duncan's multiple comparisons tests. Results There were statistically significant differences found between surface treatment groups in terms of Vickers hardness of zirconia and lithium disilicate ceramics (p 0.05). Conclusions Surface treatments could affect the hardness of ceramics. Therefore, was zirconia found to be harder and more durable than lithium disilicate ceramics.Department of Scientific Research [BAP 2013/266] Funding Source: Medlin

Comparison to Color Stability Between Amine with Benzoyl Peroxide Includes Resin Cement and Amine-reduced, Amine-free, Lacking of Benzoyl Peroxide Resin Cements After Thermocycle

WOS: 000489324700006Objective: This study aims to compare the color change (Delta E) of 5 resin cements (Panavia SA, Panavia V5, RelyX U200, Variolink NLC clear and +1) after thermocycling. Changes in color of specimens were determined after 10,000 cycles of thermocycling by spectrophotometer in the CIELAB. Materials and Methods: Ceramic disks, simulating laminate veneers, with thicknesses of 0.5, 0.7, and 1.0 mm (A1, IPS e.max) were fabricated. Color differences (Delta E) between the control and test groups were calculated. Data were statistically analyzed by 2-way analysis of variance (ANOVA). Also, Tukey's multiple comparison tests were applied to know the difference between the groups (alpha = 0.05). Results: the factors of cement type and thickness of ceramic showed significant influence on Delta E values (P < .05). After thermocycling, all resin cements, except benzoyl peroxide including resin cement (Pan SA), were showed clinically acceptable to color change limits (Delta E < 3.3). on evaluating the effects of ceramic thickness on color change after thermocyle aging, control group (no ceramic thickness) showed color change (P < .05) visually. Conclusion: Amine-reduced, amine-free and lacking benzoyl peroxide resin cement showed minimal color change and better color stability

The effect of laboratory procedures and repeated-glazing on color of metal-ceramic restoration

WOS: 000514103600011PubMed: 32308284Background: Routine laboratory procedures and repeated glazed effect the final color of metal-ceramic restorations (MCRs). Clinicians wonder if the color changes after routine laboratory procedures and repeated glazed is clinically acceptable or not. Aims: the aim of this study was to determine the color changes of MCRs after routine laboratory procedures and then glazed for 1, 2, and 3 times. Materials and Methods: Forty-five disc-shaped (10-mm diameter and 1-mm thickness) specimens were fabricated from Cr-Co metal-alloy. Bonding agent, first and second layer of shade A(2)opaque porcelain (OP) were applied on the metal specimens. the color of specimens was measured with a spectrophotometer after each procedure and Delta E-1, Delta E-2,and Delta E-3 values were calculated. Shade A(2) feldspathic porcelain was applied (2-mm thickness) to all specimens. Glaze was applied on the porcelain for 1, 2, and 3 times and then, the color measured after each procedure and Delta E-4, Delta E-5, and Delta E-6 values were calculated. Data were analyzed with one-way ANOVA and Duncan test (P < 0.05). Results: Delta E-1 that was obtained between the first layer of OP and bonding agent showed the greatest value. Delta E-2 that was obtained between the second and first layer of OP showed the lowest value. After repeated glazed procedures, the final color of the specimens was changed; but, these changes were clinically acceptable (Delta E < 5.5). Conclusions: the routine laboratory procedures and glazed for 1,2, and 3 times is effect the color of MCRs; but, the color changes were clinically acceptable (Delta E < 5.5)

Effects of multiple firings on the microstructure of zirconia and veneering ceramics

Gundogdu, Mustafa/0000-0003-2527-0392WOS: 000388249100011PubMed: 27725514The aim of study was to evaluate the effects of multiple firings on the microstructures of zirconia and two ceramics. Vita VM9 (VMZ) and Cerabien ZR (C-Z) ceramics on a zirconia framework and zirconia without veneering ceramic (WO-Z) were evaluated. Firing methods included firing two, five, and ten times (n=10). the effects of multiple firings on the surface hardness of the materials were evaluated using a Vickers hardness (HV) tester. Data were analyzed by two-way ANOVA and Tukey's test (a=0.05). After firing five and ten times, the hardness of VM-Z and C-Z increased significantly (p0.05). in the XRD analysis, zirconia had similar tetragonal (t)-monoclinic (m) phase transformations of Y-TZP after the different firing times. Clinically, multiple firings did not affect the microstructure of zirconia, but the structures of the two ceramics were affected.Scientific Research Projects Committee of Ataturk University, Erzurum [2011/70]The investigation was supported in part by Scientific Research Projects Committee of Ataturk University, Erzurum (Project no: 2011/70)

EFFECT OF SURFACE TREATMENTS ON THE BOND STRENGTH OF SOFT DENTURE LINING MATERIALS TO AN ACRYLIC RESIN DENTURE BASE

Gundogdu, Mustafa/0000-0003-2527-0392WOS: 000342543500043PubMed: 24726594Statement of problem. Adhesive failure between acrylic resin and resilient liner material is commonly encountered in clinical practice. Purpose. the purpose of this study was to evaluate the effect of different surface treatments on the bond strength of 2 different resilient lining materials to an acrylic resin denture base. Material and methods. Ninety-six dumbbell-shaped specimens were fabricated from heat-polymerized acrylic resin, and 3 mm of the material was cut from the thin midsection. the specimens were divided into 6 groups according to their surface treatments: no surface treatment (control group), 36% phosphoric acid etching (acid group), erbium:yttrium-aluminum-garnet (Er:YAG) laser (laser group), airborne-particle abrasion with 50-mu m Al2O3 particles (abrasion group), an acid+laser group, and an abrasion+laser group. the specimens in each group were divided into 2 subgroups according to the resilient lining material used: heat-polymerized silicone based resilient liner (Molloplast B) and autopolymerized silicone-based resilient liner (Ufi Gel P). After all of the specimens had been polymerized, they were stored in distilled water at 37 degrees C for 1 week. A tensile bond strength test was then performed. Data were analyzed with a 2-way ANOVA, and the Sidak multiple comparison test was used to identify significant differences (alpha=.05). the effects of the surface treatments and resilient lining materials on the surface of the denture base resin were examined with scanning electron microscopy. Results. the tensile bond strength was significantly different between Molloplast B and Ufi Gel P (P<.001). the specimens of the acid group had the highest tensile bond strength, whereas those of the abrasion group had the lowest tensile bond strength. the scanning electron microscopy observations showed that the application of surface treatments modified the surface of the denture base resin. Conclusions. Molloplast B exhibited significantly higher bond strength than Ufi Gel P. Altering the surface of the acrylic resin denture base with 36% phosphoric acid etching increased bond strength.Scientific Research Projects (Ataturk University)Ataturk University [2005/102]This study was supported by the 2005/102 numbered project of Scientific Research Projects (Ataturk University)

Effect of ceramic surface treatments on the bond strength of different composite resins

ALKURT, MURAT/0000-0001-9324-0158; Yanikoglu, Nuran/0000-0001-7677-1248WOS: 000428110700003This study was aimed to observe the relationship between the different surface treatments and the bond strength of both composite based adhesive cement and zirconia ceramic. Thirty-two zirconia ceramic discs were fabricated by following the instructions of manufacturer (5 x 5 x 1.5 mm). Four subgroups were obtained from the specimens according to the specified surface treatments respectively: (a) C: control groups: no treatment; (b) SB: sandblasting with 125 mu m aluminum oxide particles for 10 s; (c) SC: silica coating for 10 s; (d) Nd:YAG laser. the composite resin specimens Panavia F and Clearfil SA were introduced and polymerized to the treated bonding areas. Afterwards the specimens were stored in distilled water at 37 degrees C during 24 h, and the shear test was applied. the data were statistically analyzed by ANOVA and Duncan tests. the bond strength was stated significantly higher in silica coating/Panavia F group (23.35 MPa). the lowest bond strength was stated in control groups cemented with Clearfil SA (12.25 MPa). As a result it was determined that the bond strength has affected the both surface treatments and cement types (p < 0.001). the silica coating - treated zirconia ceramic recorded a significant increase in mean bond strength values

EFFECT OF REPAIR RESIN TYPE AND SURFACE TREATMENT ON THE REPAIR STRENGTH OF HEAT-POLYMERIZED DENTURE BASE RESIN

Gundogdu, Mustafa/0000-0003-2527-0392WOS: 000329590700012PubMed: 24161257Statement of Problem. Acrylic resin denture fracture is common in prosthodontic practice. When fractured denture bases are repaired, recurrent fractures frequently occur at the repair surface interface or adjacent areas. Purpose. the purpose of this study was to evaluate the effect of different surface treatments on the flexural strength of the acrylic resin denture base repaired with heat-polymerized acrylic resin, autopolymerizing resin, and light-polymerized acrylic resin. Material and Methods. Ninety-six specimens of heat-polymerized acrylic resin were prepared according to the American Dental Association Specification No. 12 (65.0 x 10.0 x 2.5 mm) and sectioned into halves to create a repair gap (3.0 x 10 x 2.5 mm). the sectioned specimens were divided into 3 groups according to their repair materials. the specimens from each group were divided into 4 subgroups according to their surface treatments: a control group without any surface treatment; an experimental group treated with methyl methacrylate monomer (MMA group); an experimental group treated with airborne-particle abrasion with aluminum oxide particles of 250-mu m particle size (abrasion group); and an experimental group treated with erbium:yttrium-aluminum-garnet laser (laser group). After the surface treatments, the 3 materials were placed into the repair gaps and then polymerized. After all of the specimens had been ground and polished, they were stored in distilled water at 37 degrees C for 1 week and subjected to a 3-point bend test. Data were analyzed with a 2-way analysis of variance, and the Tukey honestly significant difference test was performed to identify significant differences (alpha=.05). the effects of the surface treatments and repair resins on the surface of the denture base resin were examined with scanning electron microscopy. Results. Significant differences were found among the groups in terms of repair resin type (P<.001). All surface-treated specimens had higher flexural strength than controls, except the surface treated with the methyl methacrylate in the heat-polymerized group. A significant difference between the control and abrasion groups (P=.013) was found. the scanning electron microscopy observations showed that the application of surface treatments modified the surface of the denture base resin. Conclusions. the repair procedure with heat-polymerized resin exhibited significantly higher flexural strength than that of the autopolymerized and light-polymerized resins. in addition, the airborne-particle abrasion with aluminum oxide particles of 250-mu m particle size improved the flexural strength of the specimens tested

Investigation of the effects of storage time on the dimensional accuracy of impression materials using cone beam computed tomography

ALKURT, MURAT/0000-0001-9324-0158WOS: 000387529500007PubMed: 27826388PURPOSE. the storage conditions of impressions affect the dimensional accuracy of the impression materials. the aim of the study was to assess the effects of storage time on dimensional accuracy of five different impression materials by cone beam computed tomography (CBCT). MATERIALS AND METHODS. Polyether (Impregum), hydrocolloid (Hydrogum and Alginoplast), and silicone (Zetaflow and Honigum) impression materials were used for impressions taken from an acrylic master model. the impressions were poured and subjected to four different storage times: immediate use, and 1, 3, and 5 days of storage. Line 1 (between right and left first molar mesiobuccal cusp tips) and Line 2 (between right and left canine tips) were measured on a CBCT scanned model, and time dependent mean differences were analyzed by two-way univariate and Duncan's test (alpha=.05). RESULTS. For Line 1, the total mean difference of Impregum and Hydrogum were statistically different from Alginoplast (P<.05), while Zetaflow and Honigum had smaller discrepancies. Alginoplast resulted in more difference than the other impressions (P<.05). For Line 2, the total mean difference of Impregum was statistically different from the other impressions. Significant differences were observed in Line 1 and Line 2 for the different storage periods (P<.05). CONCLUSION. the dimensional accuracy of impression material is clinically acceptable if the impression material is stored in suitable conditions

Comparison of the Effects of Cytotoxicity and Antimicrobial Activities of Self-adhesive, Eugenol and Noneugenol Temporary and Traditional Cements on Gingiva and Pulp Living Cells

WOS: 000489325900007Aims and objectives: the aim of this in vitro study was to investigate the antibacterial and cytotoxic effect of cements: zinc polycarboxylate, glass ionomer, self-adhesive resin cement, eugenol-containing and eugenol-free temporary cements. Materials and methods: the agar-diffusion test was carried out on 4 types of bacteria: Streptococcus mutans (S. mutans; ATCC 35668), Streptococcus salivarius (S. salivarius; ATCC 13419), Streptococcus sangius (S. sangius; ATCC 10556), and Lactobacillus casei (L. casei; ATCC 27139). Freshly prepared cement samples were placed on a brain heart infusion medium and left at 37 degrees C for 24 hours in a CO2 incubator. Ampicillin disks of 10 mg were used as positive controls. Antimicrobial effects were determined using the zone of inhibition measurement in millimeters at 24 and 48 hours. Cytotoxicity was assessed through a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (SERVA Electrophoresis GmbH, Heidelberg, Germany). To evaluate cell viability, an optical density microplate reader (Tecan (TM) Sunrise, Mannedorf, Switzerland) was used at 24 and 48 hours at 570 and 630 nm, respectively. Results: Except the positive control group, the Adhesor luting cement showed a higher inhibitory effect on S. sangius and L. casei. RelyX Temp E temporary cement showed an inhibitory effect on S. sangius and L. casei, whereas the Cavex temporary cement showed an inhibitory effect on only S. sangius at 24 and 48 hours. At 100% concentration, Cavex temporary cement showed the least toxicity (23.6% pulp cell and 9.9% gingival cell) and highest cell viability (76.4% pulp cell and 90.1% gingival cell) at 24 hours. However, Meron, Adhesor, Panavia SA luting, and RelyX Temp E temporary cements showed the highest toxicity (above 94% gingival cell and 95% pulp cell) at 100% concentration. Conclusions: Meron, Adhesor, Panavia SA luting, and RelyX Temp E temporary cements may have a cytotoxic potential. None of the cements showed an inhibitory effect on S. mutan and S. salivarius, whereas Adhesor luting cement has a higher inhibitory effect than that of S. sangius and L. casei.Department of Recep Tayyip Erdogan University [2015/357]This study was supported by the scientific research projects, Department of Recep Tayyip Erdogan University (2015/357). It was presented at the 105th Annual World Dental Congress (FDI), Madrid, Spain, August 29 to September 1, 2017