Effects of Polishing Bur Application Force and Reuse on Sintered Zirconia Surface Topography

2018 ◽  
Vol 43 (4) ◽  
pp. 437-446 ◽  
Author(s):  
NG Fischer ◽  
A Tsujimoto ◽  
AG Baruth
Keyword(s):  
Surface Topography ◽  
Computer Aided Design ◽  
Groove Depth ◽  
Control Group ◽  
Limited Information ◽  
Average Roughness ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam

SUMMARY Objective: Limited information is available on how to polish and finish zirconia surfaces following computer-aided design/computer-aided manufacturing (CAD/CAM), specifically, how differing application forces and reuse of zirconia polishing systems affect zirconia topography. Purpose: To determine the effect of differing, clinically relevant, polishing application forces and multiple usages of polishing burs on the surface topography of CAD/CAM zirconia. Methods: One hundred twenty 220-grit carbide finished zirconia disks were sintered according to manufacturer's directions and divided into two groups for the study of two coarse polishing bur types. Each group was divided into subgroups for polishing (15,000 rpm) at 15 seconds for 1.0 N, 4.5 N, or 11 N of force using a purpose-built fixture. Subgroups were further divided to study the effects of polishing for the first, fifth, 15th, and 30th bur use, simulating clinical procedures. Unpolished surfaces served as a control group. Surfaces were imaged with noncontact optical profilometry (OP) and atomic force microscopy (AFM) to measure average roughness values (Ra). Polishing burs were optically examined for wear. Scanning electron microscopy (SEM) was performed on burs and zirconia surfaces. One-way ANOVA with post hoc Tukey HSD (honest significant difference) tests (α=0.05) were used for statistical analyses. Results: AFM and OP Ra values of all polished surfaces were significantly lower than those of the unpolished control. Different polishing forces and bur reuse showed no significant differences in AFM Ra. However, significant differences in OP Ra were found due to differing application forces and bur reuse between the first and subsequent uses. SEM and optical micrographs revealed notable bur wear, increasing with increasing reuse. SEM and AFM micrographs clearly showed polished, periodic zirconia surfaces. Nanoscale topography, as analyzed with kurtosis and average groove depth, was found dependent on the specific polishing bur type. Conclusions: These in vitro results suggest changes in OP Ra due to bur reuse and polishing application force. Within the parameters of this study, the resultant topography of zirconia polishing is force-dependent and the reuse of coarse polishing burs is possible without statistically significant differences in Ra values after initial use. Nanoscale and microscale topography were shown to depend on specific polishing bur type.

scholarly journals Evaluation of the light transmission of chairside polymer infiltrated hybrid ceramics in different shades and thicknesses

2019 ◽  
Vol 17 (1) ◽  
pp. 228080001880710 ◽  
Author(s):  
İbrahim Duran ◽  
Necati Kaleli ◽  
Çağrı Ural ◽  
İdris Kavut
Keyword(s):  
Computer Aided Design ◽  
Light Transmission ◽  
Univariate Analysis ◽  
Control Group ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam ◽  
Lower Light ◽  
Hybrid Ceramic

Background: This in vitro study aimed to evaluate the amount of polymerizing light passing through hybrid ceramic specimens in different shades and thicknesses. Methods: Rectangular-shaped feldspathic ceramic computer aided design and computer aided manufacturing (CAD-CAM) blocks and translucent and high translucent polymer infiltrated hybrid ceramic CAD-CAM blocks in four different shades (1M1, 1M2, 2M2, and 3M2) were sectioned in four different thicknesses (0.8, 1.5, 2, and 3 mm), and a total of 48 groups ( n = 10) were obtained. Feldspathic ceramic specimens served as the control group. The light transmission of each ceramic specimen was measured three times by using a light-emitting diode and a radiometer. Data were statistically analyzed by using univariate analysis of variance (ANOVA) followed by one-way ANOVA, Tukey honest significant difference, and Tamhane T2 tests (α = 0.05). Results: Translucent polymer infiltrated hybrid ceramic specimens exhibited significantly ( p < 0.001) lower light transmission values than high translucent polymer infiltrated hybrid ceramic and feldspathic ceramic specimens, whereas feldspathic ceramic specimens exhibited significantly ( p < 0.001) higher light transmission than translucent and high translucent polymer infiltrated hybrid ceramic specimens. The amount of light transmission significantly ( p < 0.05) decreased when the shade value decreased and the thickness increased. Conclusions: Polymer infiltrated hybrid ceramic specimens showed lower light transmission values than feldspathic ceramic specimens, and the amount of light transmission was affected by the ceramic shade and thickness.

Evaluation of Polishing Systems for CAD/CAM Polymer-Infiltrated Ceramic-Network Restorations

2021 ◽  
Author(s):  
CA Jurado ◽  
A Tsujimoto ◽  
H Watanabe ◽  
NG Fischer ◽  
JA Hasslen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Dental Students ◽  
Faculty Members ◽  
Dental School ◽  
Control Group ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam ◽  
A Company

SUMMARY Objective: The purpose of this study was to evaluate the effectiveness of five different polishing systems on a computer-aided design and computer-aided manufacturing (CAD/CAM) polymer-infiltrated ceramic-network restoration with nanoscale assessment using atomic force microscopy (AFM) and visual assessment performed by dental school senior students and faculty members. Method: Forty-eight full coverage crowns were milled out of polymer-infiltrated ceramic-network CAD/CAM blocks (Vita Enamic) for polishing with one company proprietary, two ceramic and two composite polishing systems. The prepared crowns were divided into six groups: (1) no polishing (control); (2) polishing with Vita Enamic Polishing Kit (VEna); (3) polishing with Shofu Porcelain Laminate Polishing Kit (SCer); (4) polishing with Brasseler Dialite Feather lite All- Ceramic Adjusting & Polishing System (BCer); (5) polishing with Shofu Composite Polishing Kit (SCom); and (6) polishing with Brasseler Composite Polishing Kit (BCom). The polished crown surface topography was observed, and surface roughness and area were measured with AFM. In addition, polished crowns were visually assessed by 15 senior dental students and 15 dental school faculty members. Results: All polishing treatments significantly reduced the surface roughness and area of the crown compared with the control. SCom and BCom showed significantly higher surface area than VEna, and the SCer and BCer groups were intermediate, showing no significant difference from either VEna or SCom and BCom. There were no significant differences in surface roughness between any of the systems. Dental students and faculty members classified the groups polished with VEna, SCer, and BCer groups as clinically acceptable, and they selected BCer group as the best polished restorations and the control group as the least polished restorations. Conclusions: Ceramic and composite polishing systems produced similar polishing results as that observed using a company proprietary polishing system. However, effectiveness for polishing using a company proprietary and ceramic polishing system tends to be higher than composite polishing systems.

scholarly journals In vitro Study of the Effect of Internal Relief Space on the Color of Ceramic Laminate Veneer

2021 ◽  
Vol 9 (D) ◽  
pp. 37-42
Author(s):  
Abd El Azeem Mostafa ◽  
Cherif A. Mohsen
Keyword(s):  
Computer Aided Design ◽  
Color Change ◽  
In Vitro Study ◽  
Resin Cement ◽  
Lithium Silicate ◽  
Standard Design ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam

BACKGROUND: Ceramic laminate veneer restoring is considered a challenging modality in solving various esthetic dental problems. AIM: The purpose of this study was to investigate the effect of digital internal relief space on the color of ceramic laminate veneer. MATERIALS AND METHODS: An acrylic central incisor model was prepared for ceramic laminate veneer with standard measures. The prepared acrylic resin dentotype model was scanned with intraoral computer-aided design/computer-aided manufacturing (CAD/CAM) optical scanner (CEREC Omnicam|Dentsply Sirona). The laminate veneer design was planned on the optically scanned preparation on CAD/CAM system software (CEREC software|Dentsply Sirona). Thirty ceramic laminate veneer specimens were machined from zirconia-reinforced lithium silicate (Celtra Duo blocks, Dentsply/Sirona) according to standard design by CAD/CAM system with the change of the digital internal relief space settings. The specimens were divided into three groups according to their digital internal relief settings (IRS) (20, 60, and 100 μm) (n = 10). Thirty epoxy dies were duplicated from the prepared acrylic model. The ceramic laminate veneer specimens were cemented to epoxy dies with total etch resin cement system according to the manufacture instructions. The color change (ΔE) of the cemented ceramic laminate veneer specimens was measured by spectrophotometer (Vita Easy shade, Ivoclar Vivadent AG, Schaan, Liechtenstein) using the CIELAB scale and L*, a*, b*. Each specimen was measured two times (before and after cementation). The value of color difference (ΔE) was calculated according to the formula: ΔE = [(L*2 - L*1)2 + (a*2 - a*1)2 + (b*2- b*1) 2]½. RESULTS: The highest mean value of ΔE was recorded in G100 group (1.91 ± 0.33), followed by G60 group (1.83 ± 0.09), with the least value recorded in G20 group (1.49 ± 0.49). Analysis of variance test revealed a statistically significant difference between groups (p = 0.024). CONCLUSION: The change of the digital IRS affects the color of ceramic laminate veneers.

Effect of Different Computer-aided Design/Computer-aided Manufacturing (CAD/CAM) Materials and Thicknesses on the Fracture Resistance of Occlusal Veneers

2018 ◽  
Vol 43 (5) ◽  
pp. 539-548 ◽  
Author(s):  
JP Andrade ◽  
D Stona ◽  
HR Bittencourt ◽  
GA Borges ◽  
LH Burnett ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Control Group ◽  
Computer Aided Manufacturing ◽  
Universal Testing ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

SUMMARY The aim was to evaluate, in vitro, the influence of different computer-aided design/computer-aided manufacturing (CAD/CAM) materials (IPS e.max CAD, Vita Enamic, and Lava Ultimate) and thicknesses (0.6 mm and 1.5 mm) on the fracture resistance of occlusal veneers. Sixty human third molars were prepared to simulate advanced erosion of the occlusal surface, and the teeth were randomly divided into six experimental groups (n=10) according to the material and thickness used to build the veneers. Ten sound teeth formed the control group. The veneers were adhesively luted and submitted to mechanical cyclic loading (1 million cycles at 200-N load). The fracture resistance test was performed in a universal testing machine. The failures were classified as “reparable” and “irreparable.” According to two-way analysis of variance and the Tukey test, the interaction (material × thickness) was significant (p=0.013). The highest fracture resistance was obtained for IPS e.max CAD at a 1.5-mm thickness (4995 N) and was significantly higher compared to the other experimental groups (p&lt;0.05). The lowest fracture resistance was obtained for Vita Enamic at 0.6 mm (2973 N), although this resistance was not significantly different from those for IPS e.max CAD at 0.6 mm (3067 N), Lava Ultimate at 0.6 mm (3384 N), Vita Enamic at 1.5 mm (3540 N), and Lava Ultimate at 1.5 mm (3584 N) (p&gt;0.05). The experimental groups did not differ significantly from the sound teeth (3991 N) (p&gt;0.05). The failures were predominantly repairable. The occlusal veneers of IPS e.max CAD, Vita Enamic, and Lava Ultimate, with thicknesses of 0.6 mm and 1.5 mm, obtained fracture resistances similar to those associated with sound teeth.

scholarly journals Marginal Gap Evaluation of Metal Onlays and Resin Nanoceramic Computer-Aided Design and Computer-Aided Manufacturing Blocks Onlays

2019 ◽  
Vol 13 (01) ◽  
pp. 017-021
Author(s):  
Nor Faharina Abdul Hamid ◽  
Wan Zaripah Wan Bakar ◽  
Zaihan Ariffin
Keyword(s):  
Statistical Analysis ◽  
Computer Aided Design ◽  
Marginal Gap ◽  
Computer Aided Manufacturing ◽  
Promising Alternative ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

Abstract Objective This study was carried out to assess and compare the marginal gap of conventionally used metal onlays and new resin nanoceramic (RNC) (Lava Ultimate block) onlays. Materials and Methods This is an in vitro study using two extracted sound human mandibular molars. One tooth was prepared to receive the metal onlays and another one for the RNC onlays which were fabricated using the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. Twelve metals and 12 ceramic onlays were fabricated before they were placed at their respective preparation and examined under the Leica stereomicroscope, M125C (Leica Microsystems, Wetzlar, Germany) for a marginal analysis. The gap width was measured at 10 predefined landmarks which included 3 points on the buccal and lingual surfaces each and 2 points each on the mesial and distal surfaces, respectively. Statistical Analysis Mann–Whitney post hoc test was used for statistical analysis (P ≤ 0.05). Results Overall, the RNC onlays showed significant lower marginal gap with the exception of the landmarks 5 and 6 (on distolingual) and no significant difference at landmark 7 (on midlingual). It was observed that the marginal gap were all within the clinically acceptable limit of 120 μm. Conclusions Based on the results obtained, it can be concluded that the RNC CAD/CAM onlays are a promising alternative to the metal onlays.

Marginal Fit of Implant-Supported All-Ceramic Zirconia Frameworks

2013 ◽  
Vol 39 (4) ◽  
pp. 417-424 ◽  
Author(s):  
Hanaa Hassan Zaghloul ◽  
Jihan Farouk Younis
Keyword(s):  
Cyclic Loading ◽  
Computer Aided Design ◽  
Control Group ◽  
Marginal Gap ◽  
Marginal Fit ◽  
Mean Values ◽  
Significant Difference ◽  
All Ceramic ◽  
Computer Aided ◽  
Cad Cam

This study evaluated the effect of fabrication techniques and cyclic loading on the vertical marginal fit of implant-supported fixed partial denture (FPD) frameworks. Thirty implant-supported 3-unit FPD frameworks were fabricated on a model system, divided into 3 equal groups (n = 10). The first group (control) was constructed from base metal alloy; the other 2 test groups were constructed from all-ceramic zirconia using a computer-aided design/computer-aided manufacturing (CAD/CAM) Cerec 3 system and a copy milling (Zirkonzahn) system. A cyclic load of 200 N was applied to each framework for up to 50,000 cycles. Linear measurements were made in micrometers of the vertical gap between the framework and the implant-supported abutment at 16 predetermined points before and after cyclic loading. The frameworks were viewed using scanning electron microscopy to inspect any fractographic features. One-way analysis of variance was performed to compare the marginal discrepancy values of the control and the 2 test groups and for each group; a t test was applied to determine whether significant changes in the fit were observed after cyclic loading (α = 0.05). The CAD/CAM group showed significantly higher marginal gap mean values (80.58 μm) than the Zirkonzahn and control groups (50.33 μm and 42.27 μm, respectively) with no significant difference. After cyclic loading, the CAD/CAM group recorded the highest marginal gap mean value (91.50 ± 4.260 μm) followed by control group (72.00 ± 2.795 μm); the Zirkonzahn group recorded the lowest marginal gap (65.37 ± 6.138 μm). Cyclic loading significantly increased the marginal gap mean values in the control group only. A marginal chip was observed in one of the CAD/CAM ceramic frameworks. Within the limitations of this study, the fabrication technique influenced the marginal fit of the implant-supported 3-unit FPD frameworks. Cyclic loading failed to change the fit of all-ceramic zirconia frameworks, whereas significant changes were found in the metal frameworks.

scholarly journals An In-Vitro Study to Evaluate the Effect of Denture Cleansing Agents on Color Stability of Denture Bases Fabricated Using CAD/CAM Milling, 3D-Printing and Conventional Techniques

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 962
Author(s):  
Saurabh Jain ◽  
Mohammed Sayed ◽  
Walaa Magdy Ahmed ◽  
Amjad Hussain Asiri Halawi ◽  
Naif Mohammed Ahmed Najmi ◽  
...  
Keyword(s):  
3D Printing ◽  
Computer Aided Design ◽  
Color Change ◽  
Color Stability ◽  
Control Group ◽  
Denture Base ◽  
Computer Aided ◽  
Cad Cam ◽  
Denture Cleansers

The current literature lacks substantial information about the effect of denture cleansers on the color stability of denture bases formed using Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) additive and CAD/CAM subtractive manufacturing techniques. This study aimed to assess the effect of two commercially available denture cleansers on the color stability of denture base resins fabricated using four different techniques. Forty-five disc-shaped specimens were fabricated using each technique. Initial color readings were recorded. Specimens were randomly divided into three subgroups (n = 15): a control group (distilled water) and two denture cleanser groups. They were immersed in these solutions, simulating 180 days of use. Final color readings were recorded. The color difference was calculated, and the data were statistically analyzed. For all the specimens, significant color changes were observed after immersion in denture cleanser solutions. The extent of color change varied according to the type of denture cleanser used. When placed in the denture cleanser solutions, the CAD/CAM subtractive group showed the maximum color change (−1.10 and −0.72), while the CAD/CAM additive (3D printing) groups showed the least color change (−0.48 and −0.54). Clinicians should choose appropriate denture cleansers for newly introduced denture base resins to minimize the changes in the color of the dentures.

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

Review of Marginal Adaptation and Fracture Resistance of Computer Aided Design/Computer Aided Manufacturer (CAD‐CAM) Fabricated Endo-crowns

2021 ◽  
pp. 196-208
Author(s):  
Abdulrahman Alhaddad ◽  
Samar Abuzinadah ◽  
Abdullah Al-Otaibi ◽  
Abrar Alotaibi ◽  
Mohsen Alfkih ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Fracture Resistance ◽  
Systemic Review ◽  
Marginal Adaptation ◽  
Marginal Gap ◽  
Computer Aided ◽  
Cad Cam ◽  
Electronic Database Search ◽  
Cause Of Failure

Background: Zirconia-based restorations have become more popular in dentistry during the last two decades. Patients choose metal-free restorations, preferring materials with similar attributes to natural teeth and similar light scattering characteristics, resulting in a nice esthetic appearance. Restoring a root canal treated teeth is one of the hot topics today. endo crown materials can be either; feldspathic, glass-ceramic, monolithic hybrid ceramic or composite material. Considering the marginal gap of endocrown, an important cause of failure of treatment, the current study evaluated the marginal gap of CAD‐CAM concocted endo-crowns. Materials and Methods: This research is an analysis systemic review study was conducted between January 2020 and October 2021. We followed the PRISMA principles and recorded this systematic review using the PROSPERO database to find and identify published literature related to the marginal adaptation of CAD-CAM-fabricated endocrown. The search will include all relevant articles through the end of 2021. Finally, 24 papers on marginal clearance and fracture resistance in coronary arteries were reviewed. Results: The electronic database search yielded 98 studies that were relevant. After cross-referencing, further seven studies were added. After a full-text analysis and duplicate reduction, 74 of the 98 articles were eliminated. 5 clinical (prospective) studies, 19 in vitro studies were found. Conclusion: This analysis of the recent literature on the marginal seating integrity and fracture resistance of CAD/CAM made-up endo-crowns showed that the endo-crown had superior marginal seating integrity than classical full crown. CAM/CAM showed statistically significant higher mean fracture resistance than MAD/MAM.

scholarly journals Single blinded in-vitro study comparing microleakage between CAD/CAM crowns milled out of feldspathic ceramic and resin nano ceramic, cemented with three resin cements

2019 ◽  
Vol 18 (4) ◽  
pp. 764-772
Author(s):  
Asa Yazdani Fard ◽  
Zuryati Ab Ghani ◽  
Zaihan Ariffin ◽  
Dasmawati Mohamad
Keyword(s):  
Computer Aided Design ◽  
Medical Science ◽  
In Vitro Study ◽  
Resin Cement ◽  
Blue Dye ◽  
Resin Cements ◽  
Etch And Rinse ◽  
Computer Aided ◽  
Cad Cam

Background: Studies on microleakage of Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) crowns are abundant. However many of them are inconclusive, especially those using self adhesive cements. Aims: To compare the microleakage between CAD/CAM crowns milled out of feldspathic ceramic and resin nano ceramics, cemented with three resin cements. Materials and Methods: Crown preparation was made on 54 extracted human premolars. Impressions were captured optically using CEREC 3D machine intraoral camera, and crowns were milled from feldspathic ceramic (CEREC® Blocs PC, VITA) and resin nano ceramic (Lava™ Ultimate CAD/CAM Restorative, 3M ESPE) blocks. The crowns were then cemented with three cements (n = 9); RelyX™ U200 Self-Adhesive Resin Cement (3M ESPE); NX3 Nexus ® cement with two-step etch-and-rinse adhesive (Kerr Corporation) or three/multistep etch-and-rinse resin cement, Variolink® II/Syntac Classic (Ivoclar Vivadent). The specimens were kept in water for 24 hours, thermocycled, and then soaked in methylene blue dye for 24 hours, before being sectioned mesiodistally. Microleakage was assessed using a fivepoint scale using stereomicroscope. Statistical analysis of the data was carried out using ONEWay ANOVA. Results: CEREC® Blocs PC crowns showed significantly less microleakage (p< 0.001) compared to Lava™ Ultimate. RelyX™ U200 showed significantly lower microleakage (p< 0.001) compared to other cements. Combination of Lava™ Ultimate crown cemented with RelyX™ U200 showed the least microleakage (p< 0.001). Conclusions: The microleakage scores were affected by the types of crown and cements. Bangladesh Journal of Medical Science Vol.18(4) 2019 p.764-772

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