scholarly journals Mechanical Stability of Screw-Retained Monolithic and Bi-layer Posterior Hybrid Abutment Crowns after Thermomechanical Loading: An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7539
Author(s):  
Frank A. Spitznagel ◽  
Estevam A. Bonfante ◽  
Tiago M. B. Campos ◽  
Maximilian A. Vollmer ◽  
Johannes Boldt ◽  
...  
Keyword(s):  
Multiple Testing ◽  
Mechanical Stability ◽  
High Reliability ◽  
In Vitro Study ◽  
Titanium Implants ◽  
Before And After ◽  
Load To Failure ◽  
Cad Cam ◽  
Failure Loads

To evaluate the failure-load and survival-rate of screw-retained monolithic and bi-layered crowns bonded to titanium-bases before and after mouth-motion fatigue, 72 titanium-implants (SICvantage-max, SIC-invent-AG) were restored with three groups (n = 24) of screw-retained CAD/CAM implant-supported-single-crowns (ISSC) bonded to titanium-bases: porcelain-fused-to-metal (PFM-control), porcelain-fused-to-zirconia (PFZ-test) and monolithic LDS (LDS-test). Half of the specimens (n = 12/group) were subjected to fatigue in a chewing-simulator (1.2 million cycles, 198 N, 1.67 Hz, thermocycling 5–55 °C). All samples were exposed to single-load-to-failure without (PFM0, PFZ0, LDS0) or with fatigue (PFM1, PFZ1, LDS1). Comparisons were statistically analyzed with t-tests and regression-models and corrected for multiple-testing using the Student–Neuman–Keuls method. All PFM and LDS crowns survived fatigue exposure, whereas 16.7% of PFZ showed chipping failures. The mean failure-loads (±SD) were: PFM0: 2633 ± 389 N, PFM1: 2349 ± 578 N, PFZ0: 2152 ± 572 N, PFZ1: 1686 ± 691 N, LDS0: 2981 ± 798 N, LDS1: 2722 ± 497 N. Fatigue did not influence load to failure of any group. PFZ ISSC showed significantly lower failure-loads than monolithic-LDS regardless of artificial aging (p < 0.05). PFM ISSC showed significantly higher failure loads after fatigue than PFZ (p = 0.032). All ISSC failed in a range above physiological chewing forces. Premature chipping fractures might occur in PFZ ISSC. Monolithic-LDS ISSC showed high reliability as an all-ceramic material for screw-retained posterior hybrid-abutment-crowns.

Effects of Polishing versus Glazing on Dental Ceramic Wear: A Comparative In Vitro Study

2021 ◽  
Vol 11 (1) ◽  
pp. 73-79
Author(s):  
Mohammed Abujalala ◽  
A. Nehir Özden
Keyword(s):  
Wear Behavior ◽  
In Vitro Study ◽  
Ceramic Materials ◽  
Volume Loss ◽  
Dental Ceramic ◽  
Chewing Simulation ◽  
System A ◽  
Before And After ◽  
Cad Cam

This study analyzed the wear behavior caused by steatite antagonists to four dental ceramic materials, comparing this between two surface treatments: polishing and glazing. Methods: Thirty flat samples (10 × 8 × 2 mm) were prepared from each of four ceramics: IPS e. max CAD (IPS), GC Initial LiSi Press (LP), Vita Enamic (VE), and monolithic zirconia (MZ). Subgroups of samples were finished by polishing or glazing or neither (as controls). The samples were subjected to computer-controlled chewing simulation (240,000 cycles of 49 N at 1.6 Hz, with thermocycling at 5/55 C), with steatite balls as antagonists. The samples and antagonists were visualized before and after the test with a laser abrasion measurement system, a CAD/CAM scanner, and electron microscopy scanning, and the volumes lost from the tested samples and antagonists were analyzed. Results: For the MZ samples, the polished samples showed significantly less volume loss than the glazed samples (0.0200 mm3 vs. 0.0305 mm3; p =0.0001), whereas there was significantly greater antagonist volume loss (0.0365 mm3 vs. 0.0240 mm3; p = 0.011). There were no significant differences between the subgroups for IPS, VE, and LP, although antagonist volume losses were non-significantly greater with the glazed samples than with the polished samples. Conclusions: Polishing MZ had adverse effects on the corresponding antagonist wear. Glazed MZ showed the lowest antagonist wear.

Mechanical stability and technical outcomes of monolithic CAD/CAM fabricated abutment‐crowns supported by titanium bases: An in vitro study

2020 ◽  
Author(s):  
João Pitta ◽  
Jenni Hjerppe ◽  
Felix Burkhardt ◽  
Vincent Fehmer ◽  
Philippe Mojon ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
In Vitro Study ◽  
Vitro Study ◽  
Cad Cam

scholarly journals Effects of polishing vs. glazing on dental ceramic wear: A comparative in vitro study

2019 ◽  
Author(s):  
Mohammed Abujalala ◽  
A.Nehir Özden
Keyword(s):  
Wear Behavior ◽  
In Vitro Study ◽  
Ceramic Materials ◽  
Volume Loss ◽  
Dental Ceramic ◽  
Chewing Simulation ◽  
System A ◽  
Before And After ◽  
Cad Cam

Abstract Background: This study analyzed the wear behavior caused by steatite antagonists to four dental ceramic materials, comparing this between two surface treatments: polishing and glazing. Methods: Thirty flat samples (10 × 8 × 2 mm) were prepared from each of four ceramics: IPS e.max CAD (IPS), GC Initial LiSi Press (LP), Vita Enamic (VE), and monolithic zirconia (MZ). Subgroups of samples were finished by polishing or glazing or neither (as controls). The samples were subjected to computer-controlled chewing simulation (240,000 cycles of 49 N at 1.6 Hz, with thermocycling at 5/55°C), with steatite balls as antagonists. The samples and antagonists were visualized before and after the test with a laser abrasion measurement system, a CAD/CAM scanner, and electron microscopy scanning, and the volumes lost from the tested samples and antagonists were analyzed.Results: For the MZ samples, the polished samples showed significantly less volume loss than the glazed samples (0.0200 mm3 vs. 0.0305 mm3; p = 0.0001), whereas there was significantly greater antagonist volume loss (0.0365 mm3 vs. 0.0240 mm3; p = 0.011). There were no significant differences between the subgroups for IPS, VE, and LP, although antagonist volume losses were non-significantly greater with the glazed samples than with the polished samples. Conclusions: Polishing MZ had adverse effects on the corresponding antagonist wear. Glazed MZ showed the lowest antagonist wear.

scholarly journals Qualitative and Semi-Quantitative Assessment of Processing-Related Surface Contamination of One- and Two-Piece CAD/CAM Abutments before and after Ultrasonic Cleaning

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3225
Author(s):  
Peter Gehrke ◽  
Cyrus Abazari ◽  
Kai Schlichter ◽  
Carsten Fischer ◽  
Dirk Duddeck ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Surface Contamination ◽  
Computer Aided Manufacturing ◽  
Inflammatory Reactions ◽  
Ultrasonic Cleaning ◽  
Computer Aided ◽  
Before And After ◽  
Cad Cam

Manufacturing processes of custom implant abutments may contaminate their surfaces with micro wear deposits and generic pollutants. Such particulate debris, if not removed, might be detrimental and provoke inflammatory reactions in peri-implant tissues. Although regulatory guidelines for adequate cleaning, disinfection, or sterilization exist, there does not appear to be a consistent application and data on the amount and extent of such contaminants is lacking. The aim of the present in vitro study was to evaluate the quality and quantity of processing-related surface contamination of computer-aided design/computer-aided manufacturing (CAD/CAM) abutments in the state of delivery and after ultrasonic cleaning. A total of 28 CAD/CAM monotype and hybrid abutments were cleaned and disinfected applying a three-stage ultrasonic protocol (Finevo protocol). Before and after cleaning, the chemical composition and the contamination of the abutments were assessed using scanning electron microscopy (SEM), dispersive X-ray spectroscopy (EDX), and computer-aided planimetric measurement (CAPM). In the delivery condition, monotype abutments showed a significantly higher amount of debris compared to hybrid abutments (4.86 ± 6.10% vs. 0.03 ± 0.03%, p < 0.001). The polishing process applied in the laboratory after bonding the hybrid abutment components reduces the surface roughness and thus contributes substantially to their purity. The extent of contamination caused by computer-aided manufacturing of custom abutments can be substantially minimized using a three-stage ultrasonic protocol.

scholarly journals Effect of Various Veneering Techniques on Bond Strength and Colour Stability of Zirconia / Veneering Ceramic after Hydrothermal Aging

2021 ◽  
Vol 10 (39) ◽  
pp. 3474-3479
Author(s):  
Rafat Sasany ◽  
Duygu Sarac ◽  
Goknil Ergun Kunt
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Resin Cement ◽  
Colour Stability ◽  
Hydrothermal Aging ◽  
Significant Difference ◽  
Before And After ◽  
Cad Cam ◽  
Ceramic Restorations

BACKGROUND The purpose of this in-vitro study was to compare the colour stability and bond strength of zirconia-based ceramic restorations after hydrothermal aging using conventional layering, heat-pressing, and multilayer veneering techniques. METHODS One hundred twenty specimens’ core (15 x 10 x 0.7) was fabricated from A2-shade zirconia CAD-CAM blocks (IPS e.max ZirCAD). Specimens were divided into 4 groups for veneering (N = 30): [(layering group (L), IPS e.max ceram), (heat – pressing group (P), IPS press), and multilayer group, IPS e max Cad for 2 different types of cement (cemented with RelyX U200 (M1) and PANAVIA SA (M2))]. Aging was performed for (5 - 55°C, 5000). Colour coordinates before and after aging were measured to calculate colour differences (ΔE00). The shear bond strength test was performed with a universal test unit. The data were analysed using the analysis of variance (ANOVA) and Tukey’s Honest Significant Difference test (alpha = 0.05). RESULTS Significant differences were found between the groups in bond strength (P < 0.001). Group M1 had the highest bond strength while Group L had the lowest bond strength. In terms of ΔE00 values, there were significant variations between the groups (P < 0.001). Group M1 had the highest colour stability, while Group M2 had the lowest colour stability. CONCLUSIONS The method of fabrication had an impact on the power of the bond between veneering ceramic and zirconia, as well as its colour stability. The restoration fabricated by a multilayer technique was cemented by resin cement (Rely X U200 Automix) which was found to be more resistant and colour stable. KEY WORDS Veneers, Heat-Press Technique, Bond Strength, Colour Different, Hydrothermal Aging.

scholarly journals Accuracy Evaluation of Additively and Subtractively Fabricated Palatal Plate Orthodontic Appliances for Newborns and Infants–An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4103
Author(s):  
Maite Aretxabaleta ◽  
Alexey Unkovskiy ◽  
Bernd Koos ◽  
Sebastian Spintzyk ◽  
Alexander B. Xepapadeas
Keyword(s):  
Layer Thickness ◽  
In Vitro Study ◽  
Orthodontic Appliances ◽  
Accuracy Evaluation ◽  
Palatal Plate ◽  
Cad Cam ◽  
Subtractive Manufacturing ◽  
Palatal Stimulation ◽  
Manufacturing Time

Different approaches for digital workflows have already been presented for their use in palatal plates for newborns and infants. However, there is no evidence on the accuracy of CAD/CAM manufactured orthodontic appliances for this kind of application. This study evaluates trueness and precision provided by different CAM technologies and materials for these appliances. Samples of a standard palatal stimulation plate were manufactured using stereolithography (SLA), direct light processing (DLP) and subtractive manufacturing (SM). The effect of material (for SM) and layer thickness (for DLP) were also investigated. Specimens were digitized with a laboratory scanner (D2000, 3Shape) and analyzed with a 3D inspection software (Geomagic Control X, 3D systems). For quantitative analysis, differences between 3D datasets were measured using root mean square (RMS) error values for trueness and precision. For qualitative analysis, color maps were generated to detect locations of deviations within each sample. SM showed higher trueness and precision than AM technologies. Reducing layer thickness in DLP did not significantly increase accuracy, but prolonged manufacturing time. All materials and technologies met the clinically acceptable range and are appropriate for their use. DLP with 100 µm layer thickness showed the highest efficiency, obtaining high trueness and precision within the lowest manufacturing time.

scholarly journals Macrophagic Inflammatory Response Next to Dental Implants with Different Macro- and Micro-Structure: An In Vitro Study

2021 ◽  
Vol 11 (12) ◽  
pp. 5324
Author(s):  
Maria Menini ◽  
Francesca Delucchi ◽  
Domenico Baldi ◽  
Francesco Pera ◽  
Francesco Bagnasco ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Dental Implants ◽  
In Vitro Study ◽  
Titanium Implants ◽  
Implant Surface ◽  
Bone Implant ◽  
Optimal Outcomes ◽  
Negative Controls ◽  
Inflammatory Effect

(1) Background: Intrinsic characteristics of the implant surface and the possible presence of endotoxins may affect the bone–implant interface and cause an inflammatory response. This study aims to evaluate the possible inflammatory response induced in vitro in macrophages in contact with five different commercially available dental implants. (2) Methods: one zirconia implant NobelPearl® (Nobel Biocare) and four titanium implants, Syra® (Sweden & Martina), Prama® (Sweden & Martina), 3iT3® (Biomet 3i) and Shard® (Mech & Human), were evaluated. After 4 h of contact of murine macrophage cells J774a.1 with the implants, the total RNA was extracted, transcribed to cDNA and the gene expression of the macrophages was evaluated by quantitative PCR (qPCR) in relation to the following genes: GAPDH, YWHAZ, IL1β, IL6, TNFα, NOS2, MMP-9, MMP-8 and TIMP3. The results were statistically analyzed and compared with negative controls. (3) Results: No implant triggered a significant inflammatory response in macrophages, although 3iT3 exhibited a slight pro-inflammatory effect compared to other samples. (4) Conclusions: All the samples showed optimal outcomes without any inflammatory stimulus on the examined macrophagic cells.

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.

Sign in / Sign up

Export Citation Format

Share Document