Evaluation of five CAD/CAM materials by microstructural characterization and mechanical tests: a comparative in vitro study

Abstract

BackgroundPolymer infiltrated ceramics and nano-ceramic resins are the new restorative materials which have been developed in order to enhance the adverse properties of glass-matrix ceramics and resin composites. The aim of the present in vitro study was to evaluate the characteristics of various CAD/CAM materials through mechanical, microstructural, and SEM analysis.MethodsFive test groups (n = 22) were formed by using the indicated CAD/CAM blocks: VITA Enamic (VITA Zahnfabrik), Lava Ultimate (3 M ESPE), IPS e.max CAD (Ivoclar Vivadent), IPS Empress CAD (Ivoclar Vivadent), and VITA Mark II (VITA Zahnfabrik). Two specimens from each test group were used for XRD and EDS analysis. Remaining samples were divided into two subgroups (n = 10). One subgroup specimens were thermocycled (5 °C to 55 °C, 30s, 10,000 cycles) whereas the other were not. All of the specimens were evaluated in terms of flexural strength, Vickers hardness, and fracture toughness. Results were statistically analyzed using two-way ANOVA, one-way ANOVA, Tukey’s HSD, and Student’s t tests (α = .05). Fractured specimens were evaluated using SEM.ResultsThe highest Vickers microhardness value was found for VITA Mark II (p < .001), however flexural strength and fracture toughness results were lowest conversely (p < .05). IPS e.max CAD was found to have the highest flexural strength (p < .001). Fracture toughness of IPS e.max CAD was also higher than other tested block materials (p < .001). Lava Ultimate and VITA Enamic’s mechanical properties were affected negatively from thermocycling (p < .05). Microhardness, flexural strength, and fracture toughness values of Lava Ultimate and VITA Enamic were found to be similar to VITA Mark II and IPS Empress CAD groups.ConclusionsIt should be realised that simulated aging process seem to affect ceramic-polymer composite materials more significantly than glass ceramics.

Evaluation of the Adaptation and Fracture Resistance of Three CAD–CAM Resin Ceramics: An In vitro Study

“…This study involves the fabrication of identical crowns on identical metal dies, this was to investigate one variance between groups Graph 1: Fracture load of groups with and without aging a conclusion that is supported by the results of the present study even though the differences recorded did not reach statistical significance in all four assessed groups. The larger fracture resistance recorded for e.Max is likely due to the interpenetrating needle-type lithium disilicate that responds better to load than the dispersed spherical charge in RNC or the fused particles of PICN; this result is in agreement with previously published results, 6,18,[26][27][28][29][30] and the literature highlights that lithium disilicate has clearly higher fracture strength than other ceramic groups. 6,18,26,[28][29][30] PICN with fused particles proved having higher strength than RNC with dispersed fillers.…”

“…The larger fracture resistance recorded for e.Max is likely due to the interpenetrating needle-type lithium disilicate that responds better to load than the dispersed spherical charge in RNC or the fused particles of PICN; this result is in agreement with previously published results, 6,18,[26][27][28][29][30] and the literature highlights that lithium disilicate has clearly higher fracture strength than other ceramic groups. 6,18,26,[28][29][30] PICN with fused particles proved having higher strength than RNC with dispersed fillers. According to Stawarczyk, the fact that PICN has higher resistance than RNC but lower than LDGC comes with the same order in hardness and wear properties to the antagonist teeth.…”

Custom-Made Direct Metal Laser Sintering Titanium Subperiosteal Implants: A Retrospective Clinical Study on 70 Patients

“…DMLS is an additive manufacturing (AM) method for creating patterns using thermal fusing (sintering) of powdered metals [40–44, 48]. DMLS models are generated directly from 3D computer data converted to STL files, which are then sliced into thin layers (typically about 0.1 mm/0.004 inches) using appropriate software.…”

“…DMLS models are generated directly from 3D computer data converted to STL files, which are then sliced into thin layers (typically about 0.1 mm/0.004 inches) using appropriate software. The laser sintering machine then produces the models on a moveable platform by applying incremental layers of the pattern metallic material [40–44, 48]. For each layer, the machine lays down a film of powdered metal with a precise thickness (approximately 0.1 mm/0.004 inches) [40–44, 48].…”

“…The introduction of new acquisition methods (cone beam computed tomography (CBCT) [37] and intraoral scanners [38]), along with the spread of processing/elaboration such as computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) software [39], new materials [40], and fabrication technologies, has dramatically changed the world of implant dentistry, opening up new perspectives.…”