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The aim of this study was to evaluate load‐bearing capacity and wear performance of experimental short fiber‐reinforced composite (SFRC) and conventional lithium‐disilicate CAD/CAM fabricated fixed partial dentures (FPDs). Two groups (n = 12/group) of three‐unit CAD/CAM fabricated posterior FPDs were made. The first group used experimental SFRC blocks, and the second group fabricated from lithium‐disilicate (IPS e.max CAD). All FPDs were luted on a zirconia testing jig with dual‐curing resin cement. Half of FPDs per group were quasi‐statically loaded until fracture. The other half experienced cyclic fatigue aging (100.000 cycles, Fmax = 500 N) before loading quasi‐statically until fracture. Fracture mode was examined using SEM. Wear test was performed using 15,000 loading cycles. Both material type and aging had a significant effect on the load‐bearing capacity of FPDs. Experimental SFRC CAD without fatigue aging had significantly the highest load‐bearing capacity (2096 ± 149N). Cyclic fatigue aging decreased the load‐bearing capacity of the SFRC group (1709 ± 188N) but increased it for the lithium‐disilicate group (1546 ± 155N). Wear depth values of SFRC CAD (29.3μm) were significantly lower compared to lithium‐disilicate (54.2μm). Experimental SFRC CAD demonstrated the highest load‐bearing capacity before and after cyclic fatigue aging, and superior wear behavior compared to the control material. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the fracture behavior of inlay-retained fixed partial dentures (IRFPDs) made of experimental short fiber-reinforced composite (SFRC) computer-aided design/computer-aided manufacturing (CAD/CAM) block before and after cyclic fatigue aging. Methods: Five groups (n=20/group) of three-unit posterior IRFPDs were fabricated. The first and second groups were CAD/CAM fabricated from experimental SFRC blocks or lithium-disilicate (IPS e.max CAD, IVOCLAR) materials, the third group comprised a three-dimensional-printed composite (Temp PRINT, GC), and the fourth and fifth groups comprised conventional laboratory flowable composite (Gradia Plus, GC) and commercial flowable SFRC (everX Flow, GC), respectively. All IRFPDs were luted into a metal jig with adhesive dual-cure resin cement (RelyX Ultimate, 3M ESPE). Half the IRFPDs per group (n=10) were subjected to fatigue aging for 10,000 cycles. The remaining half were statically loaded until fracture without fatigue aging. The load was applied vertically between triangular ridges of the buccal and lingual cusps. The fracture mode was visually examined using optical and scanning electron microscopy (SEM). Data were statistically analyzed using a two-way analysis of variance (ANOVA) followed by Tukey's HSD test. Results: ANOVA revealed that IRFPDs made of experimental SFRC CAD/CAM had the highest (P<0.05) load-bearing capacity before (2624±463 N) and after (2775±297 N) aging among all groups. Cyclic fatigue aging decreased the load-bearing capacity (P>0.05) of all tested prostheses, except for the experimental SFRC CAD/CAM and conventional laboratory composite IRFPDs (P>0.05). SEM images showed the ability of discontinuous short fibers in the experimental SFRC CAD/CAM composite to redirect and hinder crack propagation. Conclusions: CAD/CAM-fabricated IRFPDs made of experimental SFRC blocks showed promising performance in clinical testing in terms of fracture behavior. [ABSTRACT FROM AUTHOR]

This study aimed to use quantitative and qualitative evaluations based on micro-tensile bond strength (μTBS) to clarify the appropriate immediate dentin sealing (IDS) approach for improving the bonding of CAD/CAM ceramic crown restorations. Forty-eight extracted human molars were prepared to obtain standardized abutment specimens and divided into three groups: no IDS (group C: control), IDS performed by a single application of an all-in-one adhesive system (group A), and IDS performed by the combined application of an adhesive system and a flowable resin composite (group F). All specimens were restored with a ceramic crown fabricated by a chair-side CAD/CAM system and were divided into no-stress and stressed groups. After cyclic loading (78.5 N; total, 3 × 105 cycles; 90 cycles/min) on the specimens in the stressed group, all specimens were sectioned. The μTBS values for the occlusal and mesioaxial walls were measured (n = 16) and analyzed statistically. The quantitative bonding performance of groups A and F were superior to that of group C, regardless of the cyclic loading and abutment wall conditions. Group F showed the maximum bond strength and the highest bond durability in the qualitative bonding performance even under the cyclic loading condition simulating clinical mastication. [ABSTRACT FROM AUTHOR]

The effects of space setting values and restorative materials on the bonding of metal-free CAD/CAM onlay restoration were examined quantitatively and qualitatively. Seventy-two standardized MODB onlay cavities, prepared using human molars were restored under nine conditions, based on three space setting values, Increased (IC), Standard (SC, control), Decreased (DC), and three restorative block materials, resin-composites (RC), lithium disilicate glass-ceramics (LD), Feldspar ceramics (FC, control). All the restored specimens were subjected to cyclic loading and thereafter the microtensile bond strength (µ-TBS) was measured and analyzed statistically. The effect of space setting value on the µ-TBS varied with the restorative material. The bonding reliability of RC and the bonding durability of LD were significantly superior to FC. The bonding characteristics of RC under IC and DC were similar to those under SC. LD under DC and FC under IC were effective in obtaining an excellent bonding reliability relative to their SC. [ABSTRACT FROM AUTHOR]

The effect of differences in the type of restoration and adhesive resin cement system on the bonding of CAD/CAM ceramic restoration after cyclic loading was examined quantitatively and qualitatively. Seventy-two human maxillary first molars were divided into three restoration groups: MOD-inlay, MODP-onlay, and crown. Immediate dentin sealing was applied to the exposed dentin of all prepared specimens. The 24 specimens of each restoration group were further divided into another three groups, and a different adhesive resin cement system was applied to each group for cementation. All restoratives were fabricated from feldspathic-ceramic-blocks and cemented with each adhesive resin cement system according to the manufacturer's instructions. The microtensile bond-strength was measured after cyclic loading and was not significantly affected by differences in the type of restoration or adhesive resin cement system. However, the type of restorations and adhesive resin cement systems did show significant differences in terms of the bonding reliability. [ABSTRACT FROM AUTHOR]

This study examined the influences of clinical application of immediate dentin sealing (IDS) and temporary restoration (TR) on prepared abutment surfaces on the bonding of computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic crown restorations after cyclic loading. Standardized abutments were prepared in 60 human mandibular premolars. Dentin surfaces of half of the specimens were sealed with adhesive and flowable composite, while those of the other half were not sealed. A half of both sealed and non-sealed specimens were restored using a temporary cement and temporary crown. Each individual CAD/CAM ceramic crown was fabricated and cemented to an individual abutment. The restored specimens were subjected to cyclic loading, and the micro tensile bond strengths (µ-TBS) were measured. IDS contributed to an increase in the bond strength, whereas TR did not affect the bond strength. IDS restoration without TR yielded the maximum bond reliability in achieve specific µ-TBS values for the restoration and ensuring durability against debonding. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vitro study was to evaluate the effect of three different CAD/CAM processed materials on the interfacial gap, wear, and fracture resistance of endodontically treated molars. Materials and Methods: 48 maxillary molars were selected and endodontically treated. On each specimen a standardized MOD cavity was prepared. Specimens were then divided in two groups (n = 24 each) according to the build-up technique employed: G1) build-up with a bulk fill composite material (Admira Fusion X-Tra, Voco); G2: fiber post-supported buildup. Then, a 2-mm-thick standardized overlay preparation exposing enamel margins was performed. Specimens were scanned with Cerec Omnicam (Denstply Sirona) and the indirect restoration was milled with Cerec MXCL. Each group was divided into 3 subgroups (n = 8 each) according to the CAD/CAM material employed: SG1) Grandio-Bloks (Voco); SG2) Cerasmart (GC); SG3) Celtra Duo (Dentsply). Each overlay, once completed, was luted following a standardized procedure. All specimens were scanned with micro-CT at high-resolution scans (voltage 100kV, current 80A, source-to-object distance 80 mm, source-to-detector distance 220 mm, pixel binning 292, exposure time/projection 3 s). Then, specimens of each group were subjected to mechanical fatigue testing in a dual-axis chewing device (CS-4.4, SD Mechatronik). A force of 5 kg was applied using a ceramic steatite ball for 500,000 cycles. After fatigue, micro-CT scanning was performed to evaluate the interfacial gap. Replicas were obtained for external gap evaluation with SEM. Micro-CT images, before and after cycling load, were analyzed with Geomagic Software and Mimics to evaluate interfaces gap progression before and after mechanical load. Statistical analysis was performed with two-way ANOVA. Results: The interfacial gap was not significantly influenced by the build-up technique (p = 0.061). SG2 and SG3 showed a smaller gap (p = 0.001) and a higher fracture resistance rate (p = 0.0001). No differences were found between SEM and 3D gap evaluation. Conclusion: Interfacial gap and fracture resistance could be influenced by the CAD/CAM material employed to restore endodontically treated molars. [ABSTRACT FROM AUTHOR]

To examine the bonding state of metal-free CAD/CAM onlay restorations made from two popular resin composite blocks and a typical glass-ceramic block after cyclic loading, with and without immediate dentin sealing (IDS). Standardized mesial-distal-occlusalbuccal (MODB) cavities in 24 extracted human molars were prepared. The intra-cavity dentin surfaces of half of the cavities were immediately sealed with all-in-one adhesive and flowable composite, while those of the other half were not. All cavities were scanned, from which CAD/CAM onlays were fabricated from three types of block and cemented with an adhesive resin cement system. The restored specimens were subjected to cyclic loading and the intra-cavity microtensile bond strength was measured. IDS improves not only the internal bond strength, but also the bond reliability of metal-free CAD/CAM onlay restorations. The resin composite block seems to be more effective than a typical glass-ceramic block for achieving both high bond strength and excellent bond reliability. [ABSTRACT FROM AUTHOR]

The objective of this work was to compare the micro-tensile bond strength (µTBS) of CAD/CAM (Computer-Aided Design/ Computer-Aided Manufacturing) specimens cemented with different pairing of adhesives and resin-cements using two Immediate Dentin Dealing (IDS) approaches in comparison with Delay Dentin Sealing (DDS). Coronal dentin from 108 molars were divided into nine groups (n = 12) depending on the adhesive/resin-cement (A-C) assigned. Lava™ Ultimate (4 × 10 × 10 mm) was cemented according to different strategies: IDS1(cementation after dentin sealing), DDS (dentin sealing and cementation at 2-weeks), IDS2 (immediate dentin sealing and cementation at 2-weeks). Samples were sectioned and tested until failure to determine the µTBS. Failure mode was categorized as dentin/cement (DC), at Lava™ Ultimate/cement (LC) and hybrid (H). Kruskal–Wallis and Mann–Whitney U tests and influence of the type of failure on the µTBS by survival analysis with competing risk was explored. Mostly, µTBS values were equal or higher in IDS2 than DDS. In general, A-Cs that showed higher µTBS, have high percentages of LC failure. Survival analysis with competing risk between DC + H and LC values showed that some A-Cs would significantly increase the µTBS values for IDS2. A-Cs with the highest adhesion values showed a high percentage of fractures at the LC interface, suggesting that the adhesion at the adhesive/dentin interface would be higher. [ABSTRACT FROM AUTHOR]

The effects of space setting values and restorative materials on the bonding of metal-free CAD/CAM onlay restoration were examined quantitatively and qualitatively. Seventy-two standardized MODB onlay cavities, prepared using human molars were restored under nine conditions, based on three space setting values, Increased (IC), Standard (SC, control), Decreased (DC), and three restorative block materials, resin-composites (RC), lithium disilicate glass-ceramics (LD), Feldspar ceramics (FC, control). All the restored specimens were subjected to cyclic loading and thereafter the microtensile bond strength (µ-TBS) was measured and analyzed statistically. The effect of space setting value on the µ-TBS varied with the restorative material. The bonding reliability of RC and the bonding durability of LD were significantly superior to FC. The bonding characteristics of RC under IC and DC were similar to those under SC. LD under DC and FC under IC were effective in obtaining an excellent bonding reliability relative to their SC.

The effect of differences in the type of restoration and adhesive resin cement system on the bonding of CAD/CAM ceramic restoration after cyclic loading was examined quantitatively and qualitatively. Seventy-two human maxillary first molars were divided into three restoration groups: MOD-inlay, MODP-onlay, and crown. Immediate dentin sealing was applied to the exposed dentin of all prepared specimens. The 24 specimens of each restoration group were further divided into another three groups, and a different adhesive resin cement system was applied to each group for cementation. All restoratives were fabricated from feldspathic-ceramic-blocks and cemented with each adhesive resin cement system according to the manufacturer's instructions. The microtensile bond-strength was measured after cyclic loading and was not significantly affected by differences in the type of restoration or adhesive resin cement system. However, the type of restorations and adhesive resin cement systems did show significant differences in terms of the bonding reliability.

A higher chance of carrying out a successful full pulpotomy may depend on whether the coronal restoration can be completed within a single appointment. The development of chairside CAD/CAM (Computer Aided Design and Manufacturing) technology has made it possible to carry out indirect restoration of endodontically treated teeth in a single session. This study aimed to evaluate the long-term outcome of a full pulpotomy with Biodentine™ immediately covered with a chairside CAD/CAM endocrown on teeth affected by pulpitis and deep carious lesions. The investigation involved a cohort of 30 molars that were treated by pulpotomy and CAD/CAM endocrown. Clinical and radiological examinations were scheduled at 1, 6, and 12 months postoperatively. Overall, all treatments were effective at any time during the follow-up. The results of this study need to be confirmed with a longer-term follow-up to allow for comparison with the literature. This original combination of endodontic and restorative treatments provides an Endo-prosthetic continuum in a single session, with the objective of long-term success in terms of tooth health.

This study examined the influences of clinical application of immediate dentin sealing (IDS) and temporary restoration (TR) on prepared abutment surfaces on the bonding of computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic crown restorations after cyclic loading. Standardized abutments were prepared in 60 human mandibular premolars. Dentin surfaces of half of the specimens were sealed with adhesive and flowable composite, while those of the other half were not sealed. A half of both sealed and non-sealed specimens were restored using a temporary cement and temporary crown. Each individual CAD/CAM ceramic crown was fabricated and cemented to an individual abutment. The restored specimens were subjected to cyclic loading, and the micro tensile bond strengths (μ-TBS) were measured. IDS contributed to an increase in the bond strength, whereas TR did not affect the bond strength. IDS restoration without TR yielded the maximum bond reliability in achieve specific μ-TBS values for the restoration and ensuring durability against debonding.

To examine the bonding state of metal-free CAD/CAM onlay restorations made from two popular resin composite blocks and a typical glass-ceramic block after cyclic loading, with and without immediate dentin sealing (IDS). Standardized mesial-distal-occlusalbuccal (MODB) cavities in 24 extracted human molars were prepared. The intra-cavity dentin surfaces of half of the cavities were immediately sealed with all-in-one adhesive and flowable composite, while those of the other half were not. All cavities were scanned, from which CAD/CAM onlays were fabricated from three types of block and cemented with an adhesive resin cement system. The restored specimens were subjected to cyclic loading and the intra-cavity microtensile bond strength was measured. IDS improves not only the internal bond strength, but also the bond reliability of metal-free CAD/CAM onlay restorations. The resin composite block seems to be more effective than a typical glass-ceramic block for achieving both high bond strength and excellent bond reliability.

Objectives: There has been a growing interest in glass ceramic systems with good esthetics, high fracture resistance and bonding durability, and simplified fabrication techniques using CAD/CAM. The aim of this study is to compare flexural strength before and after heat treatment of two lithium disilicate CAD/CAM blocks, IPS e.max CAD (Ivoclar Vivadent) and Rosetta SM (Hass), and to observe their crystalline structures., Materials and Methods: Biaxial flexural strength was tested according to ISO 6872 with 20 disc form specimens sliced from each block before and after heat treatment. Also, the crystalline structures were observed using field-emission scanning microscopy (FE-SEM, Hitachi) and x-ray diffraction (XRD, Rigaku) analysis. The mean values of the biaxial flexural strength were analyzed by the Mann-Whitney U test at a significance level of p = 0.05., Results: There were no statistically significant differences in flexural strength between IPS e.max CAD and Rosetta SM either before heat treatment or after heat treatment. For both ceramics, the initial flexural strength greatly increased after heat treatment, with significant differences (p < 0.05). The FE-SEM images presented similar patterns of crystalline structure in the two ceramics. In the XRD analysis, they also had similar patterns, presenting high peak positions corresponding to the standard lithium metasilicate and lithium disilicate at each stage of heat treatment., Conclusions: IPS e.max CAD and Rosetta SM showed no significant differences in flexural strength. They had a similar crystalline pattern and molecular composition.