Search Results (62)

This study assessed the repair shear bond strength (SBS; MPa) and surface roughness (Ra; μm) of aged hybrid ceramic (Cerasmart270, GC) and nano-hybrid ceramic (Grandio Blocs, Voco) CAD/CAM blocks after different surface pretreatment methods. In this study, 2 mm thick Cerasmart270 and Grandio Blocs were cut into slabs (Isomet; n = 80 per group). Following aging for six months, the specimens in each CAD/CAM material were randomly divided into four groups (n: 20 each) according to the surface pretreatments: control (no pretreatment), Er:YAG laser, sandblasting, and bur grinding. A total of 10 specimens in each CAD/CAM material pretreatment group were used for Ra evaluation (Perthometer Mahr), while the other 10 were for SBS. After the application of a silane primer (G-Multi Primer, GC) and universal adhesive (G2-Bond, GC), composite build-ups (Filtek Z250; 3MESPE) were performed for the SBS evaluation. After storage in distilled water for 24 h, SBS was evaluated with a universal testing machine (Instron). SBS and Ra data were analyzed with two-way ANOVA and Tukey’s post hoc tests (p < 0.05). SBS was significantly affected by the surface pretreatment methods (p = 0.0001) and by the types of CAD/CAM material (p = 0.005). Bur grinding showed the highest SBS for both CAD/CAM materials, while the control groups yielded significantly lower SBS than bur grinding and sandblasting (p < 0.05). Er:YAG lasers did not significantly enhance the SBS compared to the control group. Sandblasting presented significantly higher SBS than lasers only in Grandio Blocs (p < 0.05). The surface pretreatment methods significantly influenced Ra (p = 0.0001); however, no significant interaction was found between the types of CAD/CAM material and the surface pretreatments (p > 0.05). Control groups exhibited, significantly, the lowest Ra for both materials (p = 0.0001), while no significant differences were observed between the other pretreatment methods. Bur grinding was identified as the most effective pretreatment method for repairing hybrid ceramic CAD/CAM materials. Full article

Objective: The purpose of this investigation was to assess and compare the internal adaptation of different distinct CAD (Computer-aided design)/CAM (Computer-aided manufacturing) endocrown materials: feldspathic porcelain, indirect composite, hybrid ceramic, reinforced lithium disilicate, and lithium disilicate, utilizing microcomputed tomography. Methods: Standardized endocrown restorations were fabricated for mandibular first molar models. A total of seventy-five restorations were evenly allocated into five groups (n = 15 each): Group I (Cerec Blocks), Group II (Lava Ultimate), Group III (PICN Vita Enamic), Group IV (Celtra Duo), and Group V (Cerec Tessera). The restorations were bonded using PANAVIA V5 adhesive resin cement. To evaluate internal adaptations within the restorations, three distinct locations were selected for the acquisition of high-resolution micro-CT scans: the margin, the axial wall, and the pulpal floor. Data were analyzed using SPSS. To identify statistically significant differences among groups, a two-way ANOVA was conducted, followed by post hoc Tukey tests. Results: The statistical analysis did not reveal significant differences in internal gap measurements across the various material groups (p = 0.055). However, significant variations were observed within individual material groups (p < 0.001) at distinct locations, with the most pronounced discrepancies in thickness evident at the pulpal floor. Conclusion: While no significant differences were observed in internal adaptations among the various endocrown materials, substantial intra-group variability, particularly in terms of pulpal floor thickness, was evident. Since the study maintained a consistent preparation design across all groups, the observed variations in internal adaptation are likely attributed to differences in material behavior rather than changes in preparation geometry. Full article

Background and Objectives: The manufacturing of single crowns using hybrid abutments is an alternative that may be interesting in clinical practice, combining the advantages of the different materials used in a personalized design for each case. The purpose of this in vitro study was to evaluate the torque loss, survival, reliability, failure mode, and strain distribution of implant-supported prostheses with zirconia (Zir) and cobalt–chromium (Co-Cr) hybrid abutments. Materials and Methods: Abutments were milled by CAD/CAM and divided into two groups according to the materials used, Zir and Co-Cr, and cemented on titanium bases screwed to dental implants. Monolithic zirconia crowns were cemented on the abutments. The implant/abutment/crown sets were subjected to thermomechanical cycling (n = 10) (2 Hz, 140 N, 1 × 10⁶ cycles, immersed in water at 5–55 °C) to evaluate the torque loss. The single load to fracture test (SLF) was performed to design the loading profiles (light, moderate, and aggressive) of the step-stress accelerated life testing (SSALT) (n = 21) to evaluate the survival and reliability. The representative fractured specimens were analyzed under optical and scanning electron microscopy. The digital image correlation (DIC) (n = 1) was performed using specimens embedded in polyurethane resin models that received static point loading, and the strain distribution was analyzed. Results: There was no difference in torque loss, survival, or reliability between zirconia and Co-Cr abutments. An analysis of the fractured surfaces showed that the abutments presented the same failure mode, where the fracture probably started in the titanium base/screw. The zirconia abutment model presented only compressive strains around the implant, while the Co-Cr abutment model showed tensile and compressive strains in the middle of the implant; however, all strains were within the clinically acceptable limits. There was a strain concentration in the titanium base close to the implant platform for both groups. Conclusions: Zirconia and Co-Cr hybrid abutments presented similar torque loss, survival, reliability, and failure modes, but the abutment material influenced the strain distribution around the implant. The titanium base screw was the weakest link in the system. Full article

The present review provides an up-to-date overview of chairside CAD/CAM materials used in restorative dentistry, focusing on their classification, properties, and clinical applications. If CAD/CAM technology was only an aspiration in the past, a higher proportion of clinics are employing it nowadays. The market is overflowing with biomaterials, and these materials are constantly evolving, making it challenging for practitioners to choose the most appropriate one, especially in correlation with patients’ medical diseases. The evolution of CAD/CAM technology has revolutionized dental practice, enabling the efficient fabrication of high-quality restorations in a single appointment. The main categories of chairside CAD/CAM materials include feldspathic ceramics, leucite-reinforced ceramics, lithium disilicate, zirconia, hybrid ceramics, and acrylic resins. The mechanical, physical, and aesthetic properties of these materials are discussed, along with their advantages and limitations for different clinical scenarios. Factors influencing material selection, such as strength, aesthetics, and ease of use, are also assessed. Ultimately, the guiding principle of dentistry is minimally invasive treatment following the particularity of the clinical case to obtain the envisioned result. Correlating all these factors, a simple, up-to-date classification is required to begin an individualized treatment. By synthesizing current evidence, this comprehensive review aims to guide clinicians in selecting appropriate chairside CAD/CAM materials to achieve optimal functional and aesthetic outcomes in restorative procedures. The integration of digital workflows and continued development of novel materials promise to further enhance the capabilities of chairside CAD/CAM systems in modern dental practice. Full article

Background/Objectives: This study aimed to investigate the microtensile bond strength (µTBS) of composite-based (Cerasmart), polymer-infiltrated (Vita Enamic), and feldspathic (Cerec) CAD/CAM blocks luted to dentin using a dual-cure resin cement (LinkForce), as well as micro-hybrid (G-aenial) and flowable composites (G-aenial Universal Flo), and evaluate the microhardness (HV) of luting materials through the CAD/CAM blocks. Methods: Cerasmart, Enamic, and Cerec were luted to dentin using three luting materials; LinkForce, G-aenial, and Universal Flo (n = 5). For HV, 117 disk-shaped specimens from LinkForce, G-aenial, and Universal Flo (n = 13) were polymerized through 3 mm thick CAD/CAM. Thirty-nine light-cured specimens without CAD/CAM were used as control. Following 24 h storage, the µTBS and HV were evaluated. Data were analyzed using the two-way ANOVA and post hoc Tukey tests (p < 0.05). Results: The µTBS to dentin and HV were significantly influenced by the type of luting material and CAD/CAM material. With all the CAD/CAM materials, LinkForce and Universal Flo exhibited a significantly similar µTBS to that of dentin (p > 0.05). Compared with the control group, all the HV values of the luting materials decreased significantly (p < 0.05). Conclusions: Heavily filled flowable composites exhibit a bonding effectiveness similar to that of dual-cure resin cements. All the luting materials showed similar HV when polymerized through the polymer-infiltrated CAD/CAM material. Full article

CAM/CAD composites are widely used as dental restoration materials due to their resistivity to wear. The purpose of this study was to determine the effect of human gingival fibroblast cells on three different computer-aided design/computer-aided manufacturing (CAD/CAM) hybrid materials with resin-based composites (RBC) and to assess their stability following cell growth. The CAM/CAD dental materials were investigated in different conditions as follows: (i) cells (human gingival fibroblasts, HFIB-Gs) incubated over the material for each sample, denoted as A; (ii) reference, the raw material, denoted as B; and (iii) materials incubated in DMEM medium, denoted as C. We employed Vicker’s hardness test, EDS, SEM, and AFM measurements as well as Raman spectroscopy to carefully characterize the surface modifications and the structural integrity of the CAM/CAD materials before and after fibroblast cell culture. The analysis of the surface in terms of morphology, roughness, structure, and plastic deformation presented no significant difference after incubation in cells or in media, proving their extraordinary stability and resilience to biofilm formation. Full article

Objective: It is hypothesized that the way nano- and micro-hybrid polymer-based composites are structured and cured impacts the way they respond to aging. Material and methods: A polymer–ceramic interpenetrating network composite (Vita Enamic/VE), an industrially polymerized (Brillinat CriosST/BC), and an in situ light-cured composite with discrete inorganic fillers (Admira Fusion5/AF5) were selected. Specimens (308) were either cut from CAD/CAM blocks (VE/BC) or condensed and cured in white polyoxymethylene molds (AF5) and subjected to four different aging conditions (n = 22): (a) 24 h storage in distilled water at 37 °C; (b) 24 h storage in distilled water at 37 °C followed by thermal cycling for 10,000 cycles 5/55 °C (TC); (c) TC followed by storage in a 75% ethanol–water solution; and (d) TC followed by a 3-week demineralization/remineralization cycling. CAD/CAM samples were also measured dry before the aging process. Three-point bending test, quantitative and qualitative fractography, instrumented indentation test (IIT), SEM, and reliability analyses were used. Uni- and multifactorial ANOVA, Tukey’s post hoc test, and Weibull analysis were performed for statistical analysis. Results: A significant (p < 0.001) and very strong effect of the parameter material was observed (η_P² > 0.9). VE exhibited two to three times higher elastic moduli and hardness parameters compared to BC and AF5, which were comparable. Strength was highest in BC but was accompanied by high beam deformation. The effect of aging was comparatively smaller and was more evident in the IIT parameters than in the flexural strength or modulus. Reliability was high (m > 15) in VE and BC, regardless of aging protocol, while it was significantly reduced in AF5 following aging protocols b-d. Conclusions: TC was the method of artificial aging with a significant impact on the measured parameters, while demineralization/remineralization cycling had little or no impact. Clinical relevance: The degradation of composites occurred irrespective of the structuring and curing method and manifested in a low deterioration in the measured properties. Full article

The surface qualities of CAD/CAM multi-layered ceramic and hybrid ceramic materials are critical for superior aesthetics and may be impaired by the application of home bleaching. The aim of this study was to assess how home bleaching affects the surface gloss, translucency parameter (TP), and surface roughness (Ra, Rq, and Rz) of different CAD/CAM multi-layered ceramic and hybrid ceramic dental materials. The two types of innovative ceramics that were tested are ultra-translucent multi-layered (UTML) zirconia and polymer-infiltrated ceramic blocks. The samples were treated using home bleaching agents. Each specimen was tested under bleached and non-bleached conditions. The surface gloss and TP of the specimens were measured using a spectrophotometer. The surface examination was performed using scanning electron microscope (SEM) images, while the average surface roughness values (Ra, Rq, and Rz) were calculated using three-dimensional SEM images obtained by an imaging analysis system. A total of 120 disc-shaped resin composite specimens was distributed randomly according to each material in two main groups (n = 60): a control group immersed in 20 mL distilled water (non-bleached) (n = 30), and a second group treated with 20 mL of a home bleaching agent (Crest 3D White Multi-Care Whitening Mouthwash) for 60 s, twice daily for seven days (bleached) (n = 30). The surface gloss, TP, and surface roughness (n = 10 per test for each group) of each group (bleached and non-bleached) was tested. An independent sample t-test was used statistically to assess the effect of home bleaching on the surface gloss, translucency, and roughness of each ceramic material and to compare the two materials. The significance level was adjusted at p ≤ 0.05. The results of the bleached UTML specimens showed no significant changes regarding surface gloss, TP, and roughness, whereas the bleached Vita Enamic specimens showed a significant reduction in surface gloss and TP and increased surface roughness. Moreover, the UTML specimens showed a significantly higher initial surface gloss and TP, and a reduced surface roughness, contrary to the Vita Enamic specimens. This study concluded that surface gloss retention, translucency, and surface roughness could be negatively influenced when subjected to home bleaching according to the type and composition of the ceramic materials. Full article

Full-arch zirconia restorations on implants have gained popularity due to zirconia’s strength and aesthetics, yet they are still associated with challenges like structural fractures, peri-implant complications, and design misfits. Advances in CAD/CAM and digital workflows offer potential improvements, but a technique that consistently addresses these issues in fixed, full-arch, implant-supported prostheses is needed. This novel technique integrates a facially and prosthetically driven treatment approach, which is divided into three phases: data acquisition, restoration design, and manufacturing/delivery. Digital tools, including intraoral scanning and photogrammetry, facilitate accurate implant positioning, while 3D design software enables functional and aesthetic validation before final milling. A dual software approach is used to reverse engineer a titanium bar from the final restoration design, ensuring a superior outcome to other protocols. The restoration incorporates a zirconia–titanium hybrid structure, optimizing strength, flexibility, and weight. The proposed workflow enhances restoration precision and predictability through a prosthetically driven treatment plan, by ensuring passivity and aligning with biological and mechanical principles to promote long-term stability. By starting with the proposed restoration design and reverse engineering the bar, while also allowing for flexibility in material and component choices, this technique accommodates both patient needs and financial considerations. This approach demonstrates potential for improving patient outcomes in full-arch implant restorations by minimizing complications associated with traditional methods. Further research is recommended to validate the technique’s efficacy and broaden its clinical applications. Full article

This narrative review aimed to evaluate the effectiveness of computer-aided design (CAD), computer-aided manufacturing (CAM) milled, and direct metal laser sintering (DMLS) titanium frameworks in hybrid denture prostheses. A structured PICO analysis and a review of ten publications were used to compare titanium frameworks for hybrid dentures made through milling, DMLS, and CAD-CAM milling. Prosthesis success, bone loss, patient satisfaction, framework fit, and biofilm adhesion were among the outcome indicators. The inclusion criteria included comparisons between DMLS and milled titanium frameworks, investigations of hybrid dentures with metal frameworks, and various study designs. The exclusion criteria included reviews, case reports, non-comparative research, and studies unrelated to hybrid dentures. A comprehensive search was performed up to December 2023 across PubMed, PubMed Central, Cochrane Library, Scopus, and Google Scholar, using terms such as CAD-CAM, dental implantation, dental prosthesis, bone loss, damaged maxilla/mandible, implant framework, and bone volume. Ten studies were available for the final analysis. These studies shed light on milled titanium framework’s relative effectiveness and characteristics versus DMLS for implant-supported hybrid dentures. This narrative analysis clarifies the critical roles of the CAD-CAM and DMLS frameworks in implant-supported hybrid dentures. Despite the significant benefits of both of these technologies, it is evident that more investigation is required to identify the optimal framework option for specific clinical scenarios, highlighting the importance of continuing research in this field. Full article

Before clinical trials are initiated, studying the mechanical performance of modern CAD/CAM restorative materials exposed to aging conditions would provide insights on their performance in service. This study evaluated the impact of thermomechanical aging on various resin composite, ceramic, hybrid, and nano-filled resin composite materials after two polymerization modes. Specimens (3 × 4 × 14 mm³) were fabricated using (n = 12 per group) a universal composite (Filtek Supreme XTE photo-polymerized for either 40 s or 120 s per layer), hybrid ceramics (BRILLIANT Crios, GC Cerasmart, Lava Ultimate, VITA ENAMIC), glass ceramics (IPS e.max CAD, VITA Suprinity PC, Straumann n!ce), or feldspar ceramics (VITABLOCS Mark II, GC Initial LRF). In each group, half of the specimens underwent thermomechanical aging. A three-point bending test was applied to all specimens and the results were statistically analyzed (α = 0.05). Glass ceramics and hybrid ceramics presented higher flexural strength values than feldspar ceramics and the universal composite before and after aging (p < 0.05). Thermomechanical cycling affected the flexural strength of all materials (p < 0.05) except Lava Ultimate, Straumann n!ce, and GC Initial (p > 0.05). The highest decrease in flexural strength after aging was found in the universal composite (40 s polymerization) (p < 0.001) and Vita Enamic (p < 0.001), while the lowest decrease was in the hybrid ceramics, Cerasmart and Lava Ultimate (p < 0.05). Extending polymerization duration reduced the aging effect on the universal composite tested. Thermomechanical aging affected the flexural strength of most materials tested. Universal composites and feldspar ceramics presented similar flexural strength values. Full article

This study aimed to measure the fracture strengths and hardness of final restorative milled and 3D-printed materials and evaluate the appropriate crown thickness for their clinical use for permanent prosthesis. One type of milled material (group M) and two types of 3D-printed materials (groups P1 and P2) were used. Their crown thickness was set to 0.5, 1.0, and 1.5 mm for each group, and the fracture strength was measured. Vickers hardness was measured and analyzed to confirm the hardness of each material. Scanning electron microscopy was taken to observe the surface changes of the 3D-printed materials under loads of 900 and 1500 N. With increased thickness, the fracture strength significantly increased for group M but significantly decreased for group P1. For group P2, the fracture strengths for the thicknesses of 0.5 mm and 1.5 mm significantly differed, but that for 1.0 mm did not differ from those for other thicknesses. The hardness of group M was significantly higher than that of groups P1 and P2. For all thicknesses, the fracture strength was higher than the average occlusal force for all materials; however, an appropriate crown thickness is required depending on the material and component. Full article

The current study aimed to compare the mechanical properties of CAD/CAM fabricated hybrid ceramic restorative materials. The current study assessed the mechanical properties of additively and subtractively manufactured CAD/CAM fabricated hybrid ceramic by conducting flexure strength test, compressive strength test, and Vickers hardness test. Flexural samples were subjected to a three-point bending test using a universal testing machine until the samples showed fracture. Moreover, samples for the compressive strength test were subjected to compression tests using a universal testing machine until samples were fractured. Samples for the Vickers hardness was tested using the Vickers hardness testing machine to determine the sample’s hardness values. There were significant differences (p = 0.0001) were observed among the additive and subtractive groups in terms of flexure strength and compressive strength test. Regarding the Vickers hardness test, significant differences (p = 0.0001) were observed between the polished and unpolished groups in additive manufacturing. However, no significant (p = 0.681) differences were observed in the subtractive manufacturing technique. The subtractive group achieved ISO specifications in terms of flexural strength and was superior to additive groups in hardness while exhibiting lower performance in compressive strength. Moreover, printing orientation had a significant influence on the performance of additive groups. Flexural strength and hardness were improved when the printing orientation was in alignment with the direction of load (90°) while compressive strength was improved when the printing orientation was perpendicular to the direction of load (0°). Full article

The primary objective of this study is to conduct a comprehensive review of the existing literature that discusses research on post and core restorations, covering aspects such as their composition, manufacturing methods, and clinical effectiveness. The methodology employed in this review encompasses the implementation of a well-defined search strategy, the establishment of criteria for inclusion and exclusion, and the selection of relevant studies to summarize their findings. To gather relevant literature published between 1993 and 2023, the research team conducted separate searches on PubMed, Web of Science, and Embase databases. In total, 168 titles were initially retrieved from these electronic databases. By applying the predefined exclusion criteria, the researchers identified 73 articles that specifically address the conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) technologies employed in post and core restorations. These treatments are commonly employed to restore teeth that have received endodontic therapy and subsequently experienced loss of dental structure. The development of computerized technology for the creation of customized posts and cores has emerged as a straightforward and efficient alternative to traditional methods. The review synthesizes papers discussing the techniques and materials involved in CAD/CAM-based construction of post and cores. It explores strategies for restoring endodontically treated teeth, highlighting both direct and indirect approaches. Commonly mentioned materials include zirconia, composite resin, and hybrid ceramics. Despite the limited literature on CAD/CAM post and core procedures, the review emphasizes the necessity of further research to assess long-term outcomes and efficacy. Additionally, it suggests including implications for future research and clinical recommendations to enhance the depth and practical relevance of the review. Full article

Pressed lithium disilicate is largely used for veneer manufacturing, but a new block formulation has recently been released on the market. This study evaluated the clinical performance of milled lithium disilicate veneers (LiSi Block, GC Co., Tokyo, Japan) realized with a fully digital or hybrid workflow using modified United States Public Health Service (USPHS) evaluation criteria and survival rates after 24 months of clinical service together with the patient’s satisfaction using the Visual Analog Scale (VAS). A total of 105 veneers on natural anterior teeth were made on twenty-nine patients with LiSi Block (GC, Tokyo, Japan). Patients were randomly divided into three groups: Group 1, 35 veneers realized with a completely digital workflow using Trios 3 (3Shape A/S, Copenhagen, Denmark); Group 2, 35 veneers realized with a completely digital workflow using Experimental IOS (GC, Tokyo, Japan); and Group 3, 35 veneers realized with a hybrid workflow. The restorations were followed up for 24 months, and the modified USPHS evaluation was performed at baseline, 12 months, and 24 months together with periodontal evaluation. Repeated measures two-way ANOVA and the Tukey test were applied to compare the modified USPHS method values (α = 0.05). STATISTICA 10.0 software and SIGMAPLOT 12.0 software were used to perform statistical analysis. There were no statistically significant differences between the three groups and with the interaction of group vs. time periods. The satisfaction scores of 7.35 ± 1.8 and 9.4 ± 0.37 were recorded before and after treatment, respectively. Milled lithium disilicate veneers showed a good clinical outcome after 2 years of clinical service. No difference was found between fully digital or hybrid workflow. Full article