scholarly journals Influence of Preparation Reconstruction on the Compressive Strength of CAD/CAM Ceramic Inlays

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Bruna Salamoni Sinhori ◽  
Luiz Clovis Cardoso Vieira ◽  
Luiz Narciso Baratieri
Keyword(s):  
Compressive Strength ◽  
Fracture Strength ◽  
Composite Resin ◽  
Resin Cement ◽  
Control Group ◽  
Tooth Structure ◽  
Ceramic Inlays ◽  
Compressive Strength Test ◽  
Cad Cam ◽  
Group 2

The aim of this study was to evaluate whether the compressive strength of lithium dissilicate ceramic inlays is influenced by the substrate (dentin or composite resin build-up) and to compare it to nonrestored teeth. Thirty freshly extracted human maxillary third molars were selected and randomly ascribed to three groups (n=10). Standardized Class II MOD preparations were made (bucco-palatal width = 2/3 of the intercuspal width and 2/3 of the width at the tooth equator for the proximal boxes), varying the extension of the preparations (Group 2: preparation limited to tooth structure; Group 3: pulpal floor of the preparation rebuilt with composite resin, IPS Empress Direct, restored with lithium dissilicate CAD/CAM ceramic inlays (e.max CAD) and cemented with a resin cement (Variolink II)). All groups were subjected to compressive strength test (1mm/min crosshead speed). The results showed that the fracture strength of G1 (control group) was significantly higher than G2 and G3, while within these groups there were no statistically significant differences. Both groups restored with lithium dissilicate restorations did not reach the fracture strength of the sound teeth but were statistically equivalent and sufficient to withstand physiologic masticatory forces.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

2021 ◽  
Vol 11 (5) ◽  
pp. 970-975
Author(s):  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
Mohammed S. Bin-Shuwaish ◽  
Rana S. Al-Hamdan ◽  
Modhi Al Deeb ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Testing Machine ◽  
Resin Cement ◽  
Control Group ◽  
Sem Images ◽  
Group 4 ◽  
Modes Of Failure ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

Effect of Endocrowns on Fracture Strength and Microleakage of Endodontically Treated Primary Molar Teeth

2019 ◽  
Vol 10 (2) ◽  
pp. 113-119
Author(s):  
Tarek Seddik ◽  
Sera Derelioglu
Keyword(s):  
Fracture Strength ◽  
Compressive Loading ◽  
Class Ii ◽  
Control Group ◽  
Second Primary ◽  
Endodontically Treated Teeth ◽  
Primary Molar ◽  
Molar Teeth ◽  
Group 2 ◽  
Group 1

Objectives: Optimal restoration of endodontically treated teeth is very important for the durability of the endodontic treatment. The focus of this study was to evaluate the fracture strength and microleakage of composite endocrowns compared with Class II composite restorations in endodontically treated primary molar teeth. Materials and Methods: 48 extracted second primary molars were divided into 2 groups. Group 1 (control): teeth with Class II and endodontic access cavities restored with G-aenial composite; group 2: endocrown restorations with G-aenial composite. After completing restorative procedures, teeth were subjected to thermal cycling (500 cycles). Compressive loading was applied to half of the samples, although the other half were immersed in 0.5% basic fucsin solution for 24 h, sectioned, and examined for dye penetration under stereomicroscope. Data were subjected to statistical analysis by the Mann-Whitney U test (α = 0.05). Results: The fracture strength of endocrowns (1741 ± 379.35 N) was significantly higher than that of the control group (1126.5 ± 405.39 N) ( P < .05). No statistical difference was found in microleakage between the 2 groups ( P > .05). Conclusion: Endocrown preparation increases the fracture strength of the final composite restoration when used in primary molar teeth. Composite endocrown restorations can be a practical and an esthetic option for restoring endodontically treated primary molar teeth.

scholarly journals Influence of time and hydration (ageing) on flexural strength of Yttrium stabilized Zirconia polycrystals (Y-TZP) fabricated with different CAD-CAM Systems

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Khulud A Al Aali ◽  
Saad Alresayes ◽  
Aasem M Alhenaki ◽  
Fahim Vohra ◽  
Tariq Abduljabbar
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Control Group ◽  
Stabilized Zirconia ◽  
Cad Cam ◽  
Group 3 ◽  
Group 2 ◽  
Cam Systems ◽  
Ageing Duration ◽  
Group 1

Objectives: To evaluate the effect of time and hydration (ageing) on flexural strength of yttrium-stabilized zirconia polycrystals (Y-TZP) zirconia fabricated from three different materials. Methods: This in-vitro study was performed from June to September 2019. Y-TZP bars, measuring 2 x 3 x 20 mm were prepared and sintered from three different materials, Group-1: LAVA™ Zirconia (3M™ ESPE, US) (control) Group-2: Vita In-Ceram YZ (VITA, Germany) and Group-3: Aadva™ Zirconia (Zr) (GC Advanced technologies Inc.). 30 zirconia bars per group were prepared using sectioning of blocks with isomet saw. Followed by sintering in furnaces for recommended temperature cycles. One side of bars were polished and beveled for flexural testing. Groups of specimens were divided into subgroups of 3 (n=10) based on the ageing (distilled water in the incubator at 37ºC) durations (48 Hrs and two and half years). Ten specimens in each material groups were not aged (controls). Samples were exposed to a static force in a three-point bend test using a universal instron-testing machine until fracture. Scanning electron microscopic assessment was performed for fractured specimens for ageing. Data was analyzed using ANOVA and Tukey post hoc test. Results: The mean flexural strength at baseline for Group-1: LAVA™ Zirconia, group (632.7 ± 136.5 MPa) 2: Vita In-Ceram YZ (1036.3 ± 229.6 MPa), and Group-3: Aadva™ Zirconia (1171.3 ± 266.3 MPa) were significantly different. Group-2 and Group-3 specimens showed higher strength compared to Group-1 specimens, irrespective of the ageing duration (p<0.05). Analysis of pooled data for flexural strength for materials by aging period (baseline, after 48 hours and after 2 and ½ years) showed that there was significant reduction of strength with increasing duration (p<0.05). Conclusions: Y-TZP showed variations in flexural strength depending on the material type. Ageing duration exhibited significant influence on the flexural strength of Y-TZP when comparing no ageing to two and half years. Vita In-Ceram YZ and Aadva Zirconia (Zr) showed higher and clinically acceptable flexural strength outcomes. doi: https://doi.org/10.12669/pjms.37.3.3996 How to cite this:Al-Aali KA, Alresayes S, Alhenaki AM, Vohra F, Abduljabbar T. Influence of time and hydration (ageing) on flexural strength of Yttrium stabilized Zirconia polycrystals (Y-TZP) fabricated with different CAD-CAM Systems. Pak J Med Sci. 2021;37(3):---------.   doi: https://doi.org/10.12669/pjms.37.3.3996 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

scholarly journals Long Term Water Storage Deteriorates Bonding of Composite Resin to Alumina and Zirconia Short Communication

2013 ◽  
Vol 7 (1) ◽  
pp. 123-125 ◽  
Author(s):  
T.T. Heikkinen ◽  
J.P Matinlinna ◽  
P.K. Vallittu ◽  
L.V.J. Lassila
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Resin Composite ◽  
Water Storage ◽  
Particulate Composite ◽  
Resin Cement ◽  
Control Group ◽  
Set Up

Objective of this study was to evaluate the effects of long term water storage and ageing on the bond strength of resin composite cement to yttria-stabilized zirconium dioxide (zirconia) and dialuminium trioxide (alumina). Substrate specimens of alumina and zirconia were air particle abraded with dialuminium trioxide before priming and application of composite resin. Priming was made with gamma metharyloxy-trimethoxysilane or acryloxypropyl-trimethoxysilane monomer after which the intermediate dimethacrylate resin was applied and photopolymerized. This was followed by curing particulate composite resin cement (Relyx ARC) to the substrate as a resin stub. The ageing methods of the specimens (n=6) were: (1) they stored four years in 37±1ºC distilled water, (2) thermocycled 8000 times between 55±1ºC and 5±1ºC, (3) stored first in water for four years and then thermocycled. Specimens which were stored dry, were used as controls. Bonding of composite resin was measured by shear-bond strength test set-up. Both thermocycling and long-term water storage decreased significantly shear bond strength values compared to the control group (from the level of 20 MPa to 5 MPa) regardless of the used primer or the type of the substrate. Combination of four years water storage and thermocyling reduced the bond strength even more, to the level of two to three megapascals. In can be concluded that water storage and thermocycling itselves, and especially combination of water storage and thermocycling can cause considerable reduction in the bond strength of composite resin cement to alumina and zirconia.

scholarly journals EFFECT OF THREE POLISHING SYSTEMS ON THE ROUGHNESS AND GLOSSINESS OF NANOCERAMIC COMPOSITE RESIN

2020 ◽  
pp. 16-18
Author(s):  
LIDYA LOLITA ◽  
ENDANG SUPRASTIWI ◽  
DEWA AYU NYOMAN PUTRI ARTINIGSIH ◽  
ANDRIA KUSWADI
Keyword(s):  
Composite Resin ◽  
Control Group ◽  
Step Method ◽  
Group 4 ◽  
One Step ◽  
Group 3 ◽  
Group 2 ◽  
Method Group ◽  
Group 1

Objective: The purpose of resin polish is to produce a restored surface that is similar to that of enamel. The objective of this study was to analyze thepolishing effect of three systems in terms of the comparative roughness or glossiness achieved with nanoceramic composite resin.Methods: Forty samples of nanoceramic composite resin were divided into four groups as follows: Group 1 was the control group, whichinvolved polymerization using Mylar strips; Group 2 involved a one-step polishing method; Group 3 involved a two-step method; and Group4 involved a four-step method. After performing these methods, the comparative roughness and glossiness of the resulting surfaces weremeasured.Results: Group 4 generated the lowest roughness value, with an almost equal value to that of the control group, which was followed by Group 3 andGroup 2. The best surface in terms of glossiness was achieved in Group 4.Conclusion: The polishing system involving the four-step method generated the lowest roughness value and the highest surface glossiness value.

scholarly journals Polymer-Based Bioactive Luting Agents for Cementation of All-Ceramic Crowns: An SEM, EDX, Microleakage, Fracture Strength, and Color Stability Study

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4227
Author(s):  
Samer Al-Saleh ◽  
Turki W. Aboghosh ◽  
Mousa S. Hazazi ◽  
Khalid A. Binsaeed ◽  
Abdulaziz M. Almuhaisen ◽  
...  
Keyword(s):  
Fracture Strength ◽  
Color Change ◽  
Testing Machine ◽  
Color Stability ◽  
Stability Study ◽  
Resin Cement ◽  
Resin Cements ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Group 2

The aim of the study was to compare microleakage and fracture loads of all ceramic crowns luted with conventional polymer resins and polymeric bioactive cements and to assess the color stability of polymeric bioactive cements. Seventy-five extracted premolar teeth were tested for fracture loads and microleakage in all-ceramic crowns cemented with two types of polymeric bioactive cements and resin cements. In addition, the degree of color change for each cement with coffee was assessed. Thirty maxillary premolar teeth for fracture loads and thirty mandibular premolar teeth for microleakage were prepared; standardized teeth preparations were performed by a single experienced operator. All prepared specimens were randomly distributed to three groups (n = 20) based on the type of cement, Group 1: resin cement (Multilink N); Group 2: polymeric bioactive cement (ACTIVA); Group 3: polymeric bioactive cement (Ceramir). The cementation procedures for all cements (Multilink, ACTIVA, and Ceramir) were performed according to the manufacturers’ instructions. All specimens were aged using thermocycling for 30,000 cycles (5–55 °C, dwell time 30 s). These specimens were tested using the universal testing machine for fracture strength and with a micro-CT for microleakage. For the color stability evaluation, the cement specimens were immersed in coffee and evaluated with a spectrometer. Results: The highest and lowest means for fracture loads were observed in resin cements (49.5 ± 8.85) and Ceramir (39.8 ± 9.16), respectively. Ceramir (2.563 ± 0.71) showed the highest microleakage compared to resin (0.70 ± 0.75) and ACTIVA (0.61 ± 0.56). ACTIVA cements showed comparable fracture loads, microleakage, and stain resistance compared to resin cements.

scholarly journals Tooth structure and fracture strength of cavities

2007 ◽  
Vol 18 (2) ◽  
pp. 134-138 ◽  
Author(s):  
José Mondelli ◽  
Fábio Sene ◽  
Renata Pereira Ramos ◽  
Ana Raquel Benetti
Keyword(s):  
Mass Loss ◽  
Fracture Strength ◽  
Composite Resin ◽  
Testing Machine ◽  
Cavity Preparation ◽  
Tooth Structure ◽  
Universal Testing ◽  
Significant Difference ◽  
Before And After

This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities (Groups I, II and III) and indirect inlay cavities (Groups IV, V and VI) were prepared maintaining standardized dimensions: 2-mm deep pulpal floors, 1.5-mm wide gingival walls and 2-mm high axial walls. Buccolingual width of the occlusal box was established at 1/4 (Groups I and IV), 1/3 (Groups II and V) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Tukey test (alpha= 0.05). 1/4-inlay cavities had higher percent mean mass loss (9.71%) than composite resin cavities with the same width (7.07%). 1/3-inlay preparations also produced higher percent mean mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50.35. Statistically significant difference (p<0.05) were observed between Groups I and IV, II and V, III and VI. Higher tooth structure loss and lower fracture strength were recorded after preparation of inlay cavities, regardless of the width of the occlusal box, compared to the direct composite resin cavities.

scholarly journals Comparison between Shear Bond Strength of Er:YAG and Er,Cr:YSGG Lasers-Assisted Dentinal Adhesion of Self-Adhering Resin Composite: An Ex Vivo Study

2020 ◽  
Vol 8 (3) ◽  
pp. 66
Author(s):  
Paul Nahas ◽  
Samir Nammour ◽  
Elie Gerges ◽  
Toni Zeinoun
Keyword(s):  
Bond Strength ◽  
Laser Irradiation ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Control Group ◽  
Tooth Structure ◽  
Resin Infiltration ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

(1) Background: Bonding composite to tooth structure is still evolving with a substitute for phosphoric acid being the main challenge. Lately, a self-adhering composite (SAC) was developed, promising to simplify bonding to tooth structure. Unfortunately, retention especially to dentin, was not as good as the gold standard three steps bonding system. During the last 2 decades, lasers were used to enhance shear bond strength of composite to tooth structure. However, the literature provided limited information regarding laser efficiency in the immediate, as well as the long term, adhesion success of SACs to dentin. The purpose of our study was to define the optimal irradiation conditions to improve the adhesion of self-adhering flowable resin composite to dentin exposed to Er:YAG and Er,Cr:YSGG laser irradiation. (2) Methods: Seventy-two freshly extracted human third molars, prepared to have flat dentinal surfaces, were randomly divided into three groups (n = 24) including a control group (Group 1) in which dentin was left without laser irradiation. The other two groups (Group 2 and 3) received standardized irradiation at a speed of 1 mm/second with Er:YAG (60 mJ; SSP mode = 50 μs; 10 Hz; fluency of 9.4 J/cm2; beam diameter: 0.9 mm; air 6 mL/min; and water 4 mL/min), and Er,Cr:YSGG: 1.5 W; fluency of 17.8 J/cm2; turbo handpiece with MX5 short insert; 20 Hz under air/water spray (65% air, 55% water). Self-adhering flowable resin was applied to dentin in all groups. Half of the specimens were stored in water for 24 h while the other half underwent 3000 thermal cycles. Later, all specimens received a shear bond strength test. Fracture observation was done first under a stereomicroscope then by using a scanning electron microscope. (3) Results: The mean values of shear bond strength for both laser-treated dentin groups (Er:YAG laser: 13.10 ± 1.291, and Er,Cr:YSGG: 14.04 ± 5.233) were higher than in the control group 1 (8.355 ± 2.297) before thermocycling. After thermocycling, shear bond strength decreased in all groups as follows: 10.03 ± 1.503, 10.53 ± 2.631, and 02.75 ± 1.583 for Er:YAG, Er,Cr:YSGG, and nonirradiated dentin, respectively. Shear bond strength values showed a significant difference between the control group (Group 1) and both lasers groups (Group 2 and 3). Statistical analysis of stereomicroscope observation revealed no significant difference between laser irradiation and failure mode (p < 0.136). SEM observation of the dentin surface in both laser-irradiated groups showed opened tubules, absence of smear layer as well as an increase of resin infiltration into dentinal tubules. (4) Conclusion: Er:YAG and Er,Cr:YSGG lasers enhance self-adhering flowable resin shear bond strength values and improve its longevity by eliminating the smear layer, opening dentinal tubules and increasing resin infiltration into the microstructure.

scholarly journals Effect of different post-cure polymerization treatment on composite resin hardness

2015 ◽  
Vol 63 (4) ◽  
pp. 426-431
Author(s):  
Ariani Rodrigues DIMER ◽  
Guilherme Anziliero AROSSI ◽  
Leonardo Haerter dos SANTOS ◽  
Diego Rafael KAPPAUN
Keyword(s):  
Composite Resin ◽  
Hardness Test ◽  
Composite Resins ◽  
Control Group ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Vickers Hardness Test ◽  
Group 1

Objective: To evaluate the influence of different additional polymerization methods on the microhardness of two direct composite resins. Methods: Direct Composite resins samples (Fill Magic and Opallis) and a Laboratory Composite Resin (Ceramage) were lightcured according to manufacturer instructions. Then, the direct resins were submitted to additional polymerization. Experimental groups were divided into (n = 5): group 1: Conventional Polymerization; group 2: Extra Light (80s); group 3: Autoclave; group 4: Laboratory Resin Ceramage. Vickers hardness test was carried out after a week of light-free storage in water, and results were subjected to ANOVA / Tukey statistical analysis. Results: Resin Lab Ceramage showed higher astatistically significant microhardness within all other resins in this study (p £ 0.05); Fill Magic showed no statistically significant difference between the groups tested compared to its control (p> 0.05); Opallis resin submitted to autoclave was the only method that showed a higher statistically significant difference compared to the control group (p £ 0.05). Conclusion: It concludes that hardness of a direct composite resin tested - Opallis - was increased by Autoclave post-cure polymerization, however, not enough to achieve the hardness of a laboratory composite. Furthermore, increasing lightcuring time does not produce a harder surface.

scholarly journals Bonding integrity and compressive strength of re-bonded, surface conditioned and Er Cr YSGG laser treated lithium disilicate ceramics

2020 ◽  
Vol 18 ◽  
pp. 228080002091095
Author(s):  
Abdulaziz M. Albaker ◽  
Laila Al Deeb ◽  
Aasem M Alhenaki ◽  
Modhi Aldeeb ◽  
Khold Al Ahdal ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Surface Treatment ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Lithium Disilicate ◽  
Positive Influence ◽  
Resin Cement ◽  
Control Group ◽  
Ysgg Laser ◽  
Treatment Regimes

Aim: The aim of the study was to investigate the shear bond strength (SBS) and compressive strength (CS) of Er Cr YSGG laser (ECL) treated, re-bonded lithium disilicate (LD) ceramic in comparison to standard conventional conditioning (hydrofluoric acid (HFA) and silane). Methods: One hundred LD ceramic disks were divided equally for SBS and CS testing. Eighty samples were conventionally surface treated and bonded to resin cement followed by de-bonding of the cement build-up. All de-bonded specimens were divided into four groups based on re-bonding surface treatments (HFA, primer, adhesive, and ECL). Resin cement build-ups were performed in 40 specimens for SBS testing (universal testing machine); however, the remaining 40 specimens were tested for CS. Ten specimens each were used as controls (surface treatment was performed once and no primary resin cement bonding) for SBS and CS assessment. Surface topography was assessed using a scanning electron microscope. Results: The maximum and minimum SBS values were shown by groups: control (33.42 ± 3.28 megapascals (MPa)); and ECL (17.50 ± 2.22 MPa) respectively. The maximum and minimum CSs were displayed by specimens in the ECL group (439.45 ± 70.68 MPa) and the control group (237.28 ± 19.96 MPa), respectively. For ECL specimens, SBS was significantly lower and CS was significantly higher as compared to control specimens. Conclusions: Application of the Er Cr YSGG laser significantly improved the CS of de-bonded ceramic specimens. However, it did not show a positive influence on the bond integrity of re-bonded ceramics in comparison to conventional surface treatment regimes.

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