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This article reports a case of maxillary rehabilitation with implant-supported fixed dental prostheses on six zirconia implants. A woman with impacted maxillary canines attended our dental clinic seeking a metal-free maxillary restoration. After the extraction of both impacted maxillary canines and the placement of autogenous bone graft, six two-piece zirconia implants with straight abutments were placed in the anterior maxilla. Two zirconia fixed dental prostheses with porcelain veneering, separated at the midline, were placed on these zirconia implants. The 10-year follow-up monitored the adequate evolution of both implants and restorations with no signs of peri-implant disease. [ABSTRACT FROM AUTHOR]

Purpose: The aims of the study were to evaluate the clinical performance and the complications of combined tooth-/implant-supported three-unit fixed partial dentures (FPDs) in the posterior mandible. Materials and Methods: A total of 78 partially edentulous patients in the posterior mandible were recruited for the study (n = 26/group). Group 1 served as the control group and received two dental implants to support a three-unit FPD. Groups 2 and 3 were the experimental groups in which one implant was placed in conjunction with support from an adjacent tooth to support a three-unit FPD. Standard implants (= 8 mm) were included in Group 2, while short implants (< 8 mm) were included in Group 3. Periapical radiographs were taken for evaluation of crestal bone loss (CBL). Modified plaque index (MPI), bleeding index (BI), and sulcus depth values of the abutment teeth were recorded at the time of FPD delivery, 6 months after FPD delivery, and annually thereafter. Recorded complications included abutment tooth intrusions, cementation failures of the restorations, porcelain chipping/delamination, framework fracture, abutment screw loosening, abutment and abutment screw fracture, and implant fracture. Results: Statistically significant differences were observed between Group 1 (0.06 ± 0.17) and Group 2 (0.18 ± 0.32) and between Group 1 and Group 3 (0.17 ± 0.30) in terms of MPI (P = .05). No difference was observed between Group 2 (0.11 ± 0.34) and Group 3 (0.14 ± 0.36) or between Group 1 (0.04 ± 0.22) and Group 2 in terms of BI. There were statistically significant differences in terms of CBL between Group 1 (0.259 ± 0.05 mm) and Group 3 (0.11 ± 0.03 mm) and between Group 2 (0.03 ± 0.03 mm) and Group 3 (P = .05). The mean abutment tooth sulcus depth was 1.11 ± 0.31 mm for Group 2 and 1.20 ± 0.46 mm for Group 3. Conclusions: Within the limitations of the current study, it was concluded that combined tooth/implant-supported prostheses (CTISPs) are a predictable treatment choice in the posterior mandible. When a CTISP is planned, it is more predictable to use a short implant than a standard-length implant. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of adhesive type and long-term aging on the shear bond strength (SBS) between silicabased ceramics and composite cement (CC). Materials and Methods: Lithium-silicate (LS), feldspathic (FD) and polymer-infiltrated ceramic (PIC) blocks were sectioned (10 x 12 x 2 mm) and divided into 24 groups considering the factors: "ceramics" (LS, FD, and PIC), "adhesive" (Ctrl: without adhesive; 2SC: 2-step conventional; 3SC: 3-step conventional; 1SU: 1-step universal), and "aging" (non-aged or aged [A]). After the surface treatments, CC cylinders (n = 15, ɸ=2mm; height = 2mm) were made and half of the samples were subjected to thermocycling (10,000) and stored in water at 37°C for 18months. The samples were submitted to SBS testing (100 kgf, 1mm/min) and failure analysis. Extra samples were prepared for microscopic analysis of the adhesive interface. SBS (MPa) data was analyzed by 3-way ANOVA and Tukey's test (5%). Weibull analysis was performed on the SBS data. Results: All factors and interactions were significant for SBS (p<0.05). Before aging, there was no significant difference between the tested groups and the respective control groups. After aging, the LS_1SU (22.18±7.74) and LS_2SC (17.32±5.86) groups exhibited significantly lower SBS than did the LS_Ctrl (30.30±6.11). Only the LS_1SU group showed a significant decrease in SBS after aging vs without aging. The LS_1SU (12.20) group showed the highest Weibull modulus, which was significantly higher than LS_2SC_A (2.82) and LS_1SU_A (3.15) groups. Conclusion: No type of adhesive applied after silane benefitted the long-term adhesion of silica-based ceramics to CC in comparison to the groups without adhesive. [ABSTRACT FROM AUTHOR]

The article discusses the innovative use of additive manufacturing technology for creating lithium disilicate ceramic restorations in dentistry. Traditionally, these restorations were made using analog pressing or subtractive milling techniques. The article presents a case study demonstrating the feasibility of 3D printing lithium disilicate crowns for natural teeth and implants, comparing the results with subtractive fabrication. The study highlights the potential benefits of additive manufacturing, such as improved precision and cost-effectiveness, while emphasizing the need for further research and optimization of the technology. [Extracted from the article]

Objective: The present paper aims to demonstrate the incorporation of the double monolithic protocol (DMP) into a chairside digital workflow to reproduce the fluorescence properties of natural teeth with chairside monolithic restorations when exposed to different light sources. Clinical Considerations: A female patient reporting dissatisfaction with her upper anterior teeth was rehabilitated using seven veneers and a three‐element bridge. The DMP was applied to the bridge, which consisted of a primary lithium disilicate framework to which leucite‐reinforced glass ceramic veneers were cemented. The fluorescence of the different substrates and ceramic restorations was evaluated throughout the rehabilitation process, under 365 and 405 nm light. Conclusions: The DMP allows chairside procedures to be optimized by achieving predictable, mechanically resistant, and esthetic restorations. Clinical Significance: The DMP is a new chairside solution for developing ceramic restorations with optimal esthetics and combined mechanical properties, eliminating the need for sintering or glazing procedures. [ABSTRACT FROM AUTHOR]

Objective: This article aims to describe a systematic method for tooth color reproduction with ceramics restorations employing artificial intelligence (AI) software named Matisse. It provides a comprehensive analysis of the entire process, beginning with shade‐taking and extending to ceramic application in a complex clinical case in the anterior region—specifically, a single central restoration supported by an implant. Clinical Considerations: The clinical case presented highlights the potential of Matisse software for generating ceramic (inSync‐Jensen Dental, USA) and staining (Miyo‐Jensen Dental, USA) recipes over a zirconia abutment (Katana‐Noritake Dental, Japan). This approach achieves an optimal single central restoration utilizing CAD‐CAM and layering techniques. Conclusions: The systematic method employing the Matisse software achieved accurate color reproduction for a single central restoration supported by an implant. This result was achieved by the dental ceramist within the first attempt and without seeing the patient in the entire process. Clinical Significance: The Matisse AI‐assisted protocol offers a systematic and scientifically grounded method for color reproduction in dentistry for indirect restorations. [ABSTRACT FROM AUTHOR]

Digital technologies represent new alternatives in prosthetic rehabilitation of all kinds of maxillary or mandibular spans. This article is composed of two parts, in which different technological aspects will be presented regarding the prosthetic restoration of frontal maxillary areas using the CAD-CAM technology, but using different material for resistance framework, both veneered with ceramic materials to restore the aesthetics. The main materials that will be used are: Co-Cr dental alloy and zirconium dioxide (zirconia). [ABSTRACT FROM AUTHOR]

Finishing and polishing dental ceramics after chairside adjustments is necessary to regain the original surface topography. Though highly subjective, visual and tactile assessment are the most practical ways to assess surface roughness clinically. Several manufacturers recommend polishing kits for specific ceramic materials that differ in efficacy. Proper polishing protocols require the use of sequential polishing instruments that reduce the size of the adjustment abrasions, improve aesthetics and reduce plaque accumulation. If polishing systems are interchanged, stepwise use of a zirconia polishing system may have a "universal" effect on different ceramic substrates. Adjusting zirconia restorations could result in phase transformation and potentially compromise flexural strength. The extent of this degradation is dependent on the yttria content of the zirconia. This may be reduced by appropriate finishing and polishing. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Overview Conclusion Clinical Significance This review aims to evaluate the current understanding and clinical applications of machinable ceramic‐reinforced composites (CRCs) and the emerging first generation of 3D‐printed CRCs in dental restorations.Machinable CRCs, introduced over a decade ago, have shown moderate success in short‐ to medium‐term clinical applications, particularly in low‐stress areas. However, their long‐term durability limitations, such as increased wear and marginal deterioration, restrict their use in high‐stress situations and full crowns. The first generation of 3D‐printed CRCs offers customization advantages but is still in early development and exhibits lower mechanical strength and higher wear rates than CAD‐CAM CRCs and traditional ceramics. Additionally, the classification and definitions surrounding CRCs remain ambiguous, as ADA categorizations do not clearly differentiate CRCs from ceramics, complicating clinical indication, usage, and billing practices.Machinable CAD‐CAM CRCs are moderately successful in low‐stress applications, while 3D‐printed CRCs show limitations in wear resistance and durability, raising concerns for their use in definitive restorations. Both require further research and clinical validation.Machinable CAD‐CAM CRCs are best suited for low‐stress applications, while 3D‐printed CRCs may be more appropriate for provisional use. Until long‐term clinical data are available, ceramics should be preferred for high‐stress or full‐coverage restorations. Clearer definitions for porcelain/ceramic and comprehensive application guidelines are urgently needed to support clinician decision‐making and improve patient outcomes. [ABSTRACT FROM AUTHOR]

Objectives: To investigate changes in the optical and mechanical properties of novel zirconia ceramics applied in dentistry after Er:YAG laser debonding and to evaluate the feasibility and value of reusing zirconia restorations debonded by an Er:YAG laser. Methods: Four types of zirconia ceramics were investigated: self-glazed zirconia (SGZ), 3Y-TZP, 4Y-PSZ and 5Y-PSZ. Forty rectangular (25 mm*8 mm*1.5 mm) specimens were fabricated for each zirconia type, and a total of 160 specimens were manufactured. The zirconia specimens were divided into four subgroups according to the applied Er:YAG laser debonding process: the control group, 4 W laser group, 5 W laser group, and 6 W laser group. For each subgroup, 10 specimens were subjected to color tests (color difference (△E) and transparency parameter (TP) tests) and subsequent mechanical tests (flexural strength (FS), elastic modulus (EM), Vickers hardness (VH) and surface roughness (Ra) tests). The △E, TP, FS, EM, VH and Ra values were measured and calculated. One random sample from each subgroup was observed by SEM. Statistical analyses were performed by one-way ANOVA followed by post hoc comparisons (α = 0.05). Results: The △E and TP values after Er:YAG laser debonding were not significantly different among the subgroups (P > 0.05). However, the 6 W laser group had the highest △E and lowest TP. The ranges of changes in △E and TP were below the clinically detectable threshold (△E = 1.2, △TP = 1.33). In terms of the mechanical properties, there were no significant differences in the FS, EM, VH or Ra among the subgroups. No obvious microcracks were detected on the surfaces of the zirconia specimens during SEM. Conclusions: Er:YAG laser debonding does not obviously affect the optical or mechanical properties of novel zirconia ceramics in dentistry. Moreover, it is potentially feasible and valuable to reuse zirconia restorations after Er:YAG laser debonding. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Material and Methods Results Conclusions Clinical Significance To analyze survival and complication rates for anterior and premolar laminate‐veneers out of different ceramic materials (feldspathic, leucite‐reinforced glass–ceramic [LRGC], lithium‐disilicate [LDS] and zirconia).A systematic literature search was conducted across multiple databases for clinical studies on ceramic laminate‐veneers with a minimum‐follow‐up of ≥ 1 year. The date of last search was on February 19, 2024. Survival, technical, esthetic and biological events were assessed for different laminate‐veneer materials at three observation periods (short‐ [1–3 years], mid‐ [4–6 years] and long‐term [≥ 7 years]).Twenty‐nine studies were included. Meta‐analysis revealed a pooled survival‐rate of 96.13% for feldspathic, 93.70% for LRGC and 96.81% for LDS at 10.4 years. No difference was found between materials. Complication rates (technical/esthetic/biological) were as follows: Feldspathic: 41.48%/19.64%/6.51%; LRGC: 29.87%/17.89%/4.4%; LDS: 6.1%/1.9%/0.45% at 10.4 years. Zirconia showed a 100% survival‐rate with no complications at 2.6 years. No long‐term data was available for zirconia.Feldspathic, LRGC and LDS laminate‐veneers showed high survival‐rates at long‐term observation. LDS slightly outperforms feldspathic and LRGC laminate‐veneers with lower long‐term complication rates. More studies providing long‐term data on zirconia laminate‐veneers are needed.Ceramic laminate‐veneers are a reliable treatment option. LDS may be preferred as a restorative material for long‐term success. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Clinical Considerations Conclusion Clinical Significance This case report illustrates a clinical scenario of a patient with insufficient crowns, gold onlays and localized tooth pain in the posterior teeth, treated with partial and full coverage lithium disilicate restorations.A female patient presented in the clinics, complaining about tooth pain and unesthetic metal restorations. After a thorough examination, diagnosis and treatment plan, the existing restorations were removed, and a defect‐oriented preparation was done to preserve as much as possible of the remaining tooth structure. Final partial and full coverage lithium disilicate restorations were delivered. After a 10‐year follow‐up no biological complications were observed. Nevertheless, one major chipping was observed in one of the upper molars. This technical complication was resolved with the fabrication of a new ceramic restoration.Lithium disilicate ceramic posterior full‐ or partial‐coverage restorations are a reliable and predictable treatment option not only for the replacement of tooth structure lost due to caries but also for the replacement of insufficient restorations.The following key factors are to be considered to pursue long‐term success with ceramic restorations: patient selection, minimal invasive tooth preparation, appropriate material selection and cementation. Nevertheless, complications are to be expected, and the patient should be informed accordingly. [ABSTRACT FROM AUTHOR]

Introduction: The esthetics of immediate implant dentistry can be challenging. Clinical considerations for immediate implant placement have demonstrated long‐term success rates comparable to traditional delayed implant protocols. However, it is a sensitive technique that requires proper treatment planning as well as meticulous execution to be predictable and successful in the long term. Methods: This clinical situation demands extensive knowledge of soft and hard tissue management for atraumatic tooth extraction followed by implant therapy, along with an understanding of the available materials to meet esthetic needs. This case report features a female patient with the chief complaint of needing to replace an anterior crown due to loss of retention. After a comprehensive oral assessment and cone beam computed tomography (CBCT) radiographic examination, it was determined that the crown on Tooth #9 was fractured at the subgingival level. Furthermore, gingival zenith positions displayed differences at the keratinized mucosa level in Teeth #7, #8, and #9, and the metal marginal areas of the porcelain‐fused‐to‐metal (PFM) crowns in the anterior area of Teeth #5, #7, #8, #9, and #10 were apparent. The procedure involved atraumatic extraction of Tooth #9, followed by immediate implant placement. Crowns on Teeth #5, #7, #8, and #10 were replaced, and veneers on Teeth #6 and #11 were fabricated using press lithium disilicate‐reinforced ceramic. Connective tissue graft (CTG) was contoured before final implant restorations. Results: The final implant crown was restored using a prefabricated abutment with a titanium base and lithium disilicate ceramic dental material. A well‐planned combined treatment, including atraumatic tooth extractions for immediate implants and ideal contouring of soft tissues, can significantly impact the outcome of esthetic restorations. Conclusions: Single immediate implant–supported crowns in the esthetic zone were able to fulfill the patient's esthetic expectations. [ABSTRACT FROM AUTHOR]

Fluorapatite glass-ceramic (GC) and yttria-stabilized zirconia (YSZ) are two commonly used ceramic materials for dental prosthetic restorations. Fluorapatite GCs are known for their outstanding biocompatibility and aesthetic characteristics, moreover, they can release fluoride ions which have anticaries effect. Nevertheless, they often lack the requisite strength and toughness to withstand high occlusal forces. Conversely, YSZ exhibits remarkable mechanical properties, however, it is susceptible to excessive wear on opposing teeth. To address these limitations, a novel fluorapatite GC-YSZ composite ceramic was designed and formed through vat photopolymerization. The effect of composition ratios of fluorapatite GC particles and YSZ fibers (0˗40 wt% YSZ) on the forming precision, mechanical properties, and tribological compatibility with GC was thoroughly investigated. The results demonstrated that optimal comprehensive performance was achieved when the YSZ fiber content reached 40 wt%, which resulted in a fracture toughness of 1.68 MPa m1/2, marking a 98.8 % increase over pure GC. The specific wear rates of the sample and the antagonistic titanium ball were reduced by 75.6 % and 63.8 %, respectively, compared with GC. In addition, the dimensional accuracy error of the green body was reduced by approximately 44 %. The design and fabrication of GC-YSZ composites offer an approach for developing high-performance all-ceramic dental materials. [ABSTRACT FROM AUTHOR]

Lithium disilicate (LS) ceramic emerges as a compelling option for customized implant abutments. However, ensuring its safety and reliability requires clarification on key aspects, notably its impact on inflammation and potential for cell adhesion. This study delves into these considerations, examining the influence of LS ceramic on cytokine release and the transcriptional profile of human gingival fibroblasts (hGFs) in direct contact with various LS surfaces. hGFs were cultured on LS disks featuring three distinct surfaces (unpolished, polished, and polished glaze), while titanium disks served as reference material and cells cultured directly on plates as controls. The surface of the disks was analyzed using a scanning electron microscope. The cell metabolism was analyzed by MTT test, cytokine release by MAGPIX and the expression of genes related to cell adhesion was evaluated by qPCR. The disks exhibited similar topography with smooth surfaces, except for the unpolished LS disks, which had an irregular surface. Contact with LS surfaces did not substantially reduce cell metabolism. Moreover, it generally decreased cytokine release compared to controls, particularly pro-inflammatory mediators like IL-1β, IL-6, and TNF-α. Significantly increased expression of genes related to cell adhesion to LS was observed, comparable to titanium, the gold standard material for implant abutments. Significance: This study unveils that LS ceramic not only fails to trigger pro-inflammatory cytokine release, but also significantly enhances gene expression associated with cell adhesion. These mechanisms are closely linked to gene pathways such as PTK2 , SRC , MAPK1 , and transcription factors ELK-1 and MYC. In summary, the findings underscore LS ceramic's potential as a biocompatible material for implant abutments, shedding light on its favorable inflammatory response and enhanced cell adhesion properties. [ABSTRACT FROM AUTHOR]

To evaluate the influence of microstructure and chemical composition on the optical properties of CAD-CAM lithium disilicate glass-ceramics. Samples (n = 5; 1.0 mm thickness) of shades A1, A2, and A3 were fabricated from CAD-CAM ceramic blocks (Ivoclar Vivadent): IPS e.max® CAD LT (emLT) and HT (emHT). Samples were polished to 1.0 ± 0.01 mm in thickness. The optical properties (R- reflectance; T- transmittance; μ s ′ - reduced scattering and μ a - absorption coefficients) from the post-crystallized samples were determined using the inverse adding-doubling (IAD) method based on integrating-sphere measurements. Additionally, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to evaluate the microstructural properties. Energy-dispersive X-ray (EDX) was employed to analyze the chemical composition. The chemical and structural characterization were performed before and after crystallization of the ceramic samples. emLT showed higher values of μ s ′ and lower values of μ a and T than emHT for each shade in all wavelengths (p < 0.003). Considering T for emHT, there were no statistical differences for shades A1 and A2 at 488 nm and 514.5 nm (p > 0.003) and shades A1 and A3 at 457.9 nm (p > 0.003). emLT showed particle length ranging from 0.74 to 2.78 µm (mean = 1.57 µm and RF-relative frequency = 28 %) and particle width ranging from 0.21 to 0.74 µm (mean = 0.30 µm and RF = 31 %). emHT showed particle length ranging from 0.83 to 3.08 µm (mean = 1.86 µm and RF = 21 %) and particle width ranging from 0.24 to 1.12 µm (mean = 0.56 µm and RF = 28 %). In comparison with emHT, emLT showed greater vol% for C, K, and Zr and lower vol% for O and Al. The optical properties of CAD-CAM lithium disilicate glass-ceramics are influenced by the chemical composition and, consequently, by the material microstructure. • The optical properties of lithium disilicate glass-ceramics are influenced by their composition and microstructure. • The transmittance of the evaluated glass-ceramics increases with wavelength. • The translucency varies with the chemical composition of the glass-ceramics. [ABSTRACT FROM AUTHOR]

Develop a sustainable bovine hydroxyapatite dental ceramic with the addition of titanium dioxide (TiO 2) nanoparticles (5 % and 8 % by weight), analyzing the outcome of this addition to the microstructure, as well as its mechanical and chemical properties, in order to evaluate whether they satisfy the International Organization for Standardization (ISO) 6872:2015 for dental ceramics or not. Disks were obtained through uniaxial followed by isostatic pressing from bovine hydroxyapatite powder and TiO 2 nanoparticles and sintered at 1300ºC for 2 h. Three experimental groups were developed (HA, HA+5 %TiO 2 and HA+8 %TiO 2) and subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), indentation fracture (IF), biaxial flexural strength (BFS) and chemical solubility test. XRD revealed, for HA group, the appearance of a peak corresponding to b-tricalcium phosphate (ß-TCP). For HA+ 5 %TiO 2 and HA+ 8 %TiO 2, the entire composition was converted into ß-TCP and calcium titanate (CaTiO 3). The SEM images showed a dense ceramic matrix and a uniform distribution of another phase in groups with TiO 2 nanoparticles. HA+ 5 %TiO 2 (1.40 ± 0.18 MPa.m1/2) and HA+ 8 %TiO 2 (1.32 ± 0.18 MPa.m1/2) showed significantly higher fracture toughness values than HA (0.67 ± 0.09 MPa.m1/2). HA showed significantly higher characteristic stress (295.8 MPa) in comparison to groups with 5 % (235.1 MPa) and 8 % (214.4 MPa) TiO 2 nanoparticles. Differences were not observed between the Weibull modulus values. The solubility results indicated that all experimental ceramics were above the 2000 ug/cm2 limit set by the ISO 6872:2015. This study proposed the development and characterization of a new ceramic for dental prosthesis made from HA extracted from bovine bones, with the intention of reusing these solids waste and transforming them into a sustainable and low-cost material. Although the experimental calcium phosphate ceramic with additions of 5 % and 8 % of TiO 2 achieved desirable mechanical properties, the chemical solubility values were very high. [Display omitted] • Bovine HA derived bioceramic with TiO 2 presents sustainability potential. • The addition of 5 % and 8 %TiO 2 significantly improved material's fracture toughness. • HA + TiO 2 bioceramic material converted microstructure to ß-TCP and CaTiO 3. • HA+TiO 2 achieved mechanical ISO standards, but failed chemical solubility limits. [ABSTRACT FROM AUTHOR]

In contemporary dental practice, clinicians have a variety of materials and options for restoring single teeth compromised by carious or non-carious diseases. According to studies and new concepts in biomimetic restorative dentistry, indirect ceramic restorations will play an increasingly important role in daily practice. We follow up and evaluate clinically three times over a 10-year period on eighty-six indirect restorations (n = 86) of lithium disilicate e.Max Press (Ivoclar, Schaan, Liechtenstein) in 32 patients. Restorations are evaluated in the 2nd, 5th, and 10th years after the fixation. Four of the restorations studied (n = 86) had to be replaced at year 5 follow-up because of fracture (failure rate: 4.65%; Kaplan–Maier). There are no restorations with bulky, cohesive fractures. Lithium disilicate ceramic restorations provide a good treatment alternative for a 5- to 10-year period of observation, and they can be successfully applied in dental practice in 91.73% to 98.84% of cases. Advancements in digital dentistry, including the use of intraoral scanners and CAD/CAM technology, are set to further refine the precision and efficiency of indirect restorations for distal teeth, enabling quicker turnaround times and improved fit. Additionally, ongoing developments in biomaterials promise to enhance the durability and biocompatibility of these restorations, potentially leading to better long-term success rates and patient satisfaction. The goal of this clinical study was to look at how well biomimetic ceramic overlays and onlays made of lithium disilicate held onto teeth with a IV-generation adhesive system for 10 years. The study also looked at how well the edges of the teeth adjusted and how strong the teeth were overall. [ABSTRACT FROM AUTHOR]

Background: Monobond Etch & Prime (MEP; Ivoclar) has a material-dependent effect on dental ceramics. This study evaluated the impact of MEP application time on the resin–ceramic shear bond strength (SBS) of lithium disilicate (LD) and advanced lithium disilicate (ALD) ceramics. Methods: LD and ALD discs were distributed into four groups (n = 20): no surface treatment; 5% HF etching followed by the application of a silane-containing primer (S); MEP applied for 40 s and maintained for 20 s; MEP applied for 2 min and maintained for 40 s. Resin–ceramic SBS was evaluated at 24 h and after thermocycling. The statistical analysis of SBS was performed by using the three-way ANOVA and Tukey's multiple comparisons tests. Additional ceramic samples were prepared to assess the surface topography. Results: There was no statistically significant difference in the SBS of the MEP groups (20 s and 2 min) and HF + S. However, only the HF + S and MEP (2 min) groups showed durable adhesion after thermocycling. MEP resulted in less distinct surface alterations compared with HF etching. Conclusion: Increasing the application time of MEP to 2 min resulted in more durable resin–ceramic adhesion compared with the application time (40 s) recommended by the manufacturer. The adhesion of resin–ceramic to LD and ALD did not significantly differ. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the effect of whitening toothpastes on the surface roughness and colour change of CAD-CAM materials. Materials and methods: A total of 96 samples (2 × 10 × 12 mm3) were prepared from Cerasmart (CS) and Celtra Duo blocks. Celtra Duo samples were divided into two groups. One group was fired with glaze paste (CDG) and the other was not treated (CD). All groups were then divided into 4 subgroups (n = 8). The groups were brushed with conventional (Colgate™ Max Fresh), silica (Opalescence™), charcoal (Curaprox™ Black in White) and blue covarine (Signal™ White Now) toothpastes for 30,000 brushing cycles. The initial and final surface roughness values were measured with contact profilometer and a dental spectrophotometer used for obtaining colour values. One sample from each brushed group was analyzed using a scanning electron microscope. Data was analyzed with Kruskal-Wallis and Mann-Whitney tests (p = 0.05). Results: The surface roughness of CS samples brushed with Opalescence™ and Curaprox™ was significantly higher than CD and CDG. Surface roughness change values of CS samples brushed with Curaprox™ were significantly higher than the CD and CDG. Curaprox™ brushed samples showed significant difference in colour change values for all materials. Conclusions: Brushing increases the surface roughness of CAD-CAM ceramic materials. The roughness of resin-based materials is higher than zirconia-reinforced lithium silicates. Silica-contained toothpastes may cause discoloration of nanoceramic and zirconia-reinforced glass ceramic restorations. Clinical relevance: It should be clinically considered that whitening toothpastes may cause roughness in ceramic materials and change the desired color. [ABSTRACT FROM AUTHOR]

Background: When discolored teeth are repaired with porcelain veneers, the thickness of the restorations should be increased appropriately using opaque porcelain and bonded by applying opaque luting resin cement to cover discolored substrates. However, its impact on the opalescent performance has not been reported yet. Purpose: To analyze the effects of opacity, body porcelain layer thickness, and luting resin cement on the opalescence properties of porcelain veneer restorations for discolored teeth. Methods: Ninety IPS d. SIGN A3 porcelain veneer specimens were prepared via powder–paste coating and sintering. Specimens were divided into three groups according to ceramic type and cement used or not: body porcelain group as control, body/opaque porcelain group and body/opaque porcelain–resin cement composite group. Each group was subdivided into three subgroups based on the thickness, 0.50, 0.75, and 1.00 mm (n = 10). Variolink N Bleach XL luting resin cement with thickness of 0.1 mm was applied to the bottoms of body/opaque porcelain specimens to produce body/opaque porcelain–resin cement composites. The opalescence (OP) values were calculated and the micromorphological characteristics were analyzed by scanning electron microscope (SEM). Statistical analysis was performed by using ANOVA test (P < 0.05). Results: The opalescence values determined for the body porcelain groups with thicknesses of 0.50, 0.75, and 1.00 mm and body/opaque porcelain specimens with thicknesses of 0.45/0.05, 0.70/0.05, and 0.95/0.05 mm were 3.35 ± 0.15, 3.83 ± 0.10, 6.73 ± 0.25, 7.95 ± 0.34, 15.16 ± 0.60, and 16.49 ± 0.89, respectively. The specimens in the body and body/opaque porcelain groups exhibited significant increases in their opalescence values with increasing thickness (P = 0.00). The opalescence values of the specimens increased significantly with the addition of a 0.05 mm opaque porcelain layer (P = 0.00). The opalescence values of the composites containing body/opaque porcelain layers with thicknesses of 0.45/0.05, 0.70/0.05, and 0.95/0.05 mm and luting resin cement were 9.46 ± 0.17, 16.47 ± 0.15, and 18.38 ± 0.47, respectively. The opalescence values of the composite specimens increased significantly with an increase in the thickness of the porcelain layer(P = 0.00). Conclusions: The opaque porcelain layer and opaque resin cement can significantly improve the opalescence properties of porcelain laminate veneers for discolored teeth, but the opalescence performance is still poor than natural teeth. The body porcelain only contributes to opalescence within a certain thickness range. [ABSTRACT FROM AUTHOR]

Porous zirconia scaffolds manufactured using polymer-infiltrated ceramic network (PICN) and additive manufacturing technologies are emerging as promising alternatives to traditional ceramic materials in dental restorations. However, incomplete osseointegration and bacterial infections still represent challenges for the long-term performance of this new composite material. To address this, the present study aims to investigate the effect of peptide biofunctionalization on the biological performance of infiltrated zirconia scaffold surfaces. The samples used in the work consisted of a 3D-printed zirconia scaffold infiltrated with a dimethacrylate copolymer. Surface biofunctionalization was achieved using a synthetic platform containing the cell-adhesive sequence RGD and the antibacteria LF1-11 peptide (RGD-LF). The attachment of the molecule was characterized through fluorescence confocal laser scanning microscopy and X-ray photoelectron spectroscopy. The biological performance of the samples was evaluated in terms of human mesenchymal stem cell adhesion and early attachment of S. aureus. The physicochemical characterization verified the successful anchoring of the biomolecule to the surface, leading to a peptide density of 288 pmol/cm2. The biological assays confirmed the potential of RGD-LF to improve cell adhesion and spreading. In this sense, the average cell area increased fourfold in the biofunctionalized surface. Regarding bacterial adhesion, it was demonstrated that RGD-LF significantly inhibited it, reducing early adhesion by half compared to the untreated surface. Overall, this study provides valuable insights into the biofunctionalization of polymer-infiltrated 3D scaffolds for the development of cell-instructive and antibacterial surfaces tailored for dental applications. [ABSTRACT FROM AUTHOR]

Introduction Methods Results Conclusion AI is based on automated learning algorithms that use large bodies of information (big data). In the field of dentistry, AI allows the analysis of radiographs, intraoral images and other clinical recordings with unprecedented precision and speed. Facial analysis is known for helping dentists and patients achieve a satisfactory result when a restorative treatment must be realized. The objective of this study is to conduct a neural network‐based computerized facial analysis using Python programming language in order to valuate its efficacy in facial point detection.The neural network was trained to identify the main facial and dental points: smile line, lips, size and for of the teeth, etc. A facial analysis was carried out using AI. A descriptive analysis was made with calculation of the mean and standard deviation (SD) of the precision and accuracy in each group. Analysis of variance (ANOVA) was used for the comparison of means between groups.At the intersecting point between dentistry and technology, advances in artificial intelligence (AI) are producing a change in the way modern dentistry is performed. The present study evidenced lesser variability in the execution times of the neural network compared with the DSD system. This indicates that the neural network affords more consistent and predictable results, representing a significant advantage in terms of time and efficacy.The neural network is significantly more efficient and consistent in performing facial analyses than the conventional DSD system. The neural network reduces the time needed to complete the analysis and shows lesser variability in its execution times. [ABSTRACT FROM AUTHOR]

Background: To evaluate the comprehensive effect of translucency, thickness, cement shades, and background color on the masking ability of resin-matrix ceramic veneer restorations. Methods: Resin-matrix ceramic specimens with 2 translucencies (LT, HT) and 3 thicknesses (0.5, 1.0, and 1.5 mm) were made of Upcera Hyramic (A2 shade). Cement specimens were made of Variolink N in 4 shades (yellow, white, transparent, and bleach XL). Five background specimens were made of IPS Natural Die Material in 5 shades (ND1, ND2, ND3, ND4, and ND5). Color coordinates of 120 subgroups (n = 5) of combined specimens composed of different ceramic, cement, and background specimens were obtained using a spectroradiometer. Color difference (ΔE00) compared with a 4-mm thick specimen of LT and HT ceramics was calculated and four-way ANOVA was used for statistical analysis (α = 0.05). Results: Translucency, thickness, cement shade, background color, and their interaction had significant effects on ΔE00 (p < 0.001). ΔE00 values of HT groups were always higher than that of LT groups and were greater than 1.8 against all background colors. ΔE00 values of LT groups could be achieved to be less than 1.8 with appropriate thickness and cement shade. ΔE00 value decreased with increasing ceramic thickness. The effect of cement shade on ΔE00 had no obvious regularity, but ΔE00 values of bleach XL cement shade group were always lower than other cement shade groups under ND3 and ND5 background color. Conclusions: The masking ability of CAD-CAM resin-matrix ceramics can be simultaneously affected by translucency, thickness, cement shade, and background color. Resin-matrix ceramics with low translucency has a better masking ability than that with high translucency. The masking ability of CAD-CAM resin-matrix ceramics increase with increasing thickness. Cement shade has less impact on the final color of resin-matrix ceramic restorations. [ABSTRACT FROM AUTHOR]

Background: This study evaluates the fracture strength and patterns of feldspathic porcelain restorations made using CAD/CAM technology for lower first molars with extensive crown destruction. The restorations include post-core and full-contour crown, composite resin core and full-contour crown, and endocrown. This research provides insights into effective restorative options to address tooth fracture risk, supporting minimally invasive procedures and CAD/CAM integration in dental practices. Methods: This study utilized 80 permanent mandibular first molars, which were divided into four groups: Group I (Post-Core-Full-contour crown), Group II (Core- Full-contour crown), Group III (Endocrown), and Group IV (Control). Root canal treatment was performed on all samples except for the control group. Following access cavity preparation, restorations for each tooth were fabricated using the CAD/CAM system and cemented with resin cement. The specimens were embedded in acrylic blocks. After undergoing thermomechanical aging, the samples were subjected to fracture resistance testing using a universal testing machine, which applied force until fracture occurred. The fracture patterns were subsequently analyzed, and the data were statistically evaluated using the Kruskal-Wallis and Chi-Square tests (p < 0.05). Results: A significant difference in fracture values under axial forces was observed (p < 0.05). The control group had the highest fracture strength (1830 ± 277 N), while the Core- full-contour crown group showed the lowest (1532 ± 371 N). Failure types varied significantly among the groups (χ2 = 26.886, df = 9, p = 0.001). The most common failure type was Type-2 (33.75%), characterized by restorable fractures, while Type-3 fractures, unrestorable, were the least common (12.5%). Conclusions: The findings underscore the significance of technological advancements in CAD/CAM for effectively restoring endodontically treated teeth with extensive crown damage. This study contributes valuable insights, emphasizing the clinical relevance of selecting appropriate restorative options to mitigate the risk of tooth fracture associated with coronal restoration failures. [ABSTRACT FROM AUTHOR]

Objective: Dental implants placed in adolescent patients pose a challenge to restore and maintain an esthetic outcome over longer period of follow‐up. Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. This case report describes an alternate prosthetic treatment strategy for maxillary single implant placed in an adolescent patient in the esthetic zone with inappropriate implant axis and screw hole placement. Clinical considerations: With temporary restorations, the gingiva and soft tissues were shaped to imitate the emerging profile of the contralateral side. A zirconia screw‐retained abutment was customized as a copy‐mirror from the contralateral prepared tooth to mimic the exact shape and to avoid labiolingual over contour by computer‐aided design/computer‐assisted manufacture (CAD/CAM). The porcelain laminate veneer was bonded to the zirconia abutment. Porcelain adhesive approach was used instead of traditional principles of retention and resistance form of the abutment. Conclusions: A functional and esthetic outcome was achieved and maintained, while a minimally invasive procedure was implemented to use the malplaced implant instead of explanting it. Clinical significance: The present report illustrates the prosthetic management of a malpositioned dental implant placed 20 years ago, utilizing a minimally invasive digital protocol. [ABSTRACT FROM AUTHOR]

The clinical failure mode of dental crown ceramics involves radial cracking at the interface, driven by the surface tension generated from the flexure of the ceramic layer on the subsurface. This results in a reduced lifespan for most all-ceramic dental crowns. Therefore, investigating optimal material combinations to reduce stress concentration in dental crown materials has become crucial for future successful clinical applications. The anisotropic complex structures of natural materials, such as nacre, could potentially create suitable strong and damage-resistant materials. Their imitation of natural structural optimisation and mechanical functionality at both the macro- and micro-levels minimises weaknesses in dental crowns. This research aims to optimise cost-effective, freeze-casted bioinspired composites for the manufacture of novel, strong, and tough ceramic-based dental crowns. To this end, multilayer alumina (Al 2 O 3) composites with four different polymer phases were tested to evaluate their bending behaviour and determine their flexural strength. A computational model was developed and validated against the experimental results. This model includes Al 2 O 3 layers that undergo gentle compression and distribute stress, while the polymer layers act as stress relievers, undergoing plastic deformation to reduce stress concentration. Based on the experimental data and numerical modelling, it was concluded that these composites exhibit variability in mechanical properties, primarily due to differences in microstructures and their flexural strength. Furthermore, the findings suggest that bioinspired Al 2 O 3 -based composites demonstrate promising deformation and strengthening behaviour, indicating potential for application in the dental field. [Display omitted] [ABSTRACT FROM AUTHOR]

The primary aim of this in vitro study was to compare the load-bearing capacity of lithium disilicate occlusal veneers, fabricated via different manufacturing processes. Secondary objectives included assessing internal accuracy and production time-efficiency. Four fabrication methods for ultra-thin lithium disilicate occlusal veneers on extracted human molars with simulated erosive defects were compared (n = 20/group): CAM: milled lithium disilicate (IPS e.max CAD); HPR: heat-pressed lithium disilicate (IPS e.max Press) out of a milled PMMA template (Ddpmma CAST); 3DP: 3D-printed lithium disilicate (experimental lithium disilicate); PTE: heat-pressed lithium disilicate (IPS e.max Press) out of a 3D-printed template (SilaPrint cast). Internal accuracy was measured prior to thermo-mechanical aging, followed by static loading to measure the load-bearing capacity (F max). Fabrication time (time-efficiency) was also recorded. Statistical analysis was performed using the Kruskal-Wallis (KW) test. No statistically significant differences were found in median load-bearing capacities (F max) between the groups (KW p = 0.5902): CAM 1821 N, HPR 1896 N, 3DP 2003 N, PTE 1687 N. Significant differences were found in internal accuracy between the groups that employed printing processes (3DP, PTE) and all other groups in margins (p < 0.001), cusps (p < 0.0018), and fossae (p < 0.0346). The time-efficiency measurements indicated an increase in fabrication time, starting from CAM 67.2 ± 5.8 min, followed by HPR 200.8 ± 33.0 min, PTE 289.2 ± 38.7 min, and peaking with the highest duration observed for 3DP 701.6 ± 8.1 min. The fabrication method of ultra-thin lithium disilicate occlusal veneers does not significantly impact their load-bearing capacity, but affects the clinical fit and adaptation of the veneers. • All fabrication methods exhibited high load-bearing capacities, with no significant differences between the groups. • Milled or heat-pressed restorations demonstrated minimal marginal discrepancies and high internal accuracy. • 3D-printed restorations showed larger marginal gaps but superior internal accuracy in the cusp and fossa regions. • Direct milling was the most time-efficient; 3D-printing the most time-consuming, and procedures involving methacrylate-based templates were intermediate. [ABSTRACT FROM AUTHOR]

Zirconia dental ceramics have evolved from uniform blocks of 3 mol.% yttria (3Y) to strength- and color-graded blocks containing 3 mol.% and 5 mol.% components. Relatively little is known about the graded materials' compositions and microstructures. Concerns have been raised about aging and degradation. This study investigated the microstructure, elemental composition, and phase content of different zones of strength- and color-graded zirconia blocks using scanning electron microscopy, x-ray fluorescence, and x-ray diffraction. Specimens were made from green-state blocks using CAD/CAM machining and sintering. Two strength- and color-graded zirconia materials had different grain sizes, elemental compositions, and phase contents between their top and bottom zones, these data being internally consistent as well as being broadly consistent with prior compositional physical property data. A color-graded zirconia material did not exhibit substantial differences between its top and bottom zones, consistent with expectations and previously published data. Modeling phase content for complex yttria-doped zirconia crystal systems with multiple heterogeneous crystal lattices from XRD data was inherently difficult, which may account for the ranges among previously published data; authors should describe detailed methodologies. Detailed compositional data at the scale of the microstructure is needed to relate composition to phase content, physical behavior, including crack evolution. [ABSTRACT FROM AUTHOR]

Objective: This study assessed the effect of the anodization of titanium abutments on the color parameters and color difference of lithium disilicate (LDS) all‐ceramic crowns. Materials and Methods: In this study, 19 straight abutments were divided into two groups: anodized (n = 9) and non‐anodized control (n = 9), with one hybrid zirconia abutment as a reference. Anodization was achieved by applying 63 V energy using seven 9 V flat batteries in series, with an electrolyte solution comprising 1 g trisodium phosphate in 250 mL distilled water for 5 s, resulting in a gold‐yellow color. Abutments were then scanned, and full‐contour monolithic IPS e.max maxillary central incisor crowns were fabricated with 2 mm thickness and glazed. Reflectance was measured using a spectroradiometer, and color coordinates (L*, a*, b*, h*, and C*) were calculated using CS‐10W software. Color differences of the crowns in both groups were quantified using the CIEDE2000 (ΔE00) color difference formula and analyzed by t‐test (α = 0.05) compared to the standard sample. Results: The L*, a*, b*, and c* parameters in anodized abutments were significantly higher than those in non‐anodized abutments, while the h* parameter in anodized abutments was significantly lower than that in non‐anodized abutments (p < 0.001 for all). There was a significant difference in ΔE00 of the two groups (p = 0.043). Conclusion: Anodization of titanium abutments improved the color parameters of LDS all‐ceramic crowns and significantly decreased their ΔE compared with non‐anodized abutments. Clinical Relevance: The research findings indicate that the anodization of titanium abutments significantly impacts color parameters, leading to lighter, redder, and more color‐saturated samples compared to non‐anodized ones. This suggests that anodization can optimize color matching in dental restorations, particularly in esthetic dentistry where precise color reproduction is crucial for natural‐looking results. Implementing anodization techniques may enhance the overall esthetic outcomes of dental prosthetics, providing clinicians with a valuable tool to improve patient satisfaction and confidence in their smiles. [ABSTRACT FROM AUTHOR]

Ceramic dental restorative materials have growing popularity, albeit their brittle and stochastic nature are acknowledged shortcomings that impact the prosthesis lifespan. The mechanical performance of ceramics is dominated by the constitutional microstructural and fracture toughness mechanisms, as well as externally applied triggers. Thus, there is ongoing expanding research in the sphere of ceramic material engineering and thermal refinement, addressing concerns regarding toughness, machinability, reliability, stainability, and biodegradation. While the current trend in dental ceramic manufacturing has transitioned from micrometric crystalline sizes to submicrometric and nanometric ranges, there is an unclear understanding of the microstructural implications on ceramic behaviour. Therefore, this review covers the comprehensive characterisation approaches commonly employed in the scientific literature to describe the multifaceted performance aspects as well as clinical-related prerequisites of dental ceramics. Moreover, updated standardised testing parameters and performance thresholds pertaining to ceramic mannerisms are described in an attempt to translate their clinical applicability. [ABSTRACT FROM AUTHOR]

The precision of the luting protocol plays a crucial role in the success and survival rate of porcelain laminate veneers (PLVs). This in vitro study aimed to evaluate the influence of different luting techniques on the positioning of PLVs through a novel, noninvasive, scanning-based technique. A total of 45 ceramic PLVs were milled and cemented on human tooth replicas. Specimens were divided into three groups of 15, each subjected to a different luting protocol: flowable composite (Group A), dual-cure resin cement (Group B), and preheated composite resin (Group C). After luting procedures, specimens were scanned, and every STL file was superimposed with the original tooth design in Geomagic Control X version 2022.1 software to assess linear (incisal, mid, cervical) and angular discrepancies. Statistical analysis was performed using one-way ANOVA, Tukey's HSD tests, and regression analysis. ANOVA results showed no statistically significant differences for incisal (F = 0.327, p = 0.723), mid (F = 0.287, p = 0.752), cervical (F = 0.191, p = 0.827), and angular (F = 0.026, p = 0.975) measurements. Tukey's HSD post hoc tests confirmed the lack of significant pairwise differences between groups. The study demonstrated that the type of luting agent used does not significantly impact the final position of PLVs. This suggests flexibility in the choice of luting agents without compromising the accuracy of PLV placement. [ABSTRACT FROM AUTHOR]

The rapid evolution of lithium silicate-based glass ceramics in the field of dental ceramics has led to the availability of different compositions in the market. This in vitro study was conducted to assess an effective protocol for recementing de-bonded lithium silicate-based glass ceramics by evaluating the shear bond strength of three reseating methods. The study included IPS e.max® CAD, Vita Suprinity®, Celtra Duo®, and n!ce as lithium-based glass ceramics. The samples underwent a series of preparation steps, including embedding in acrylic resin, hand polishing, etching with 5% hydrofluoric acid, and application of universal primer and adhesive as per manufacturer instructions. Subsequently, adhesive resin cement was applied to the ceramic tablets, and shear bond strength was assessed using a standardized method. The findings revealed that no single method demonstrated significantly superior results compared to the others. However, it was observed that etching with 5% hydrofluoric acid for 20 s yielded favorable outcomes in terms of time efficiency and standardized results. Additionally, it was noted that although sandblasting increased surface area, it did not enhance bond strength due to unfavorable surface disturbance. In conclusion, the study suggests that etching with 5% hydrofluoric acid for 20 s is a favorable protocol for reseating de-bonded lithium disilicate-based glass ceramics, offering both time efficiency and consistent results for clinicians. [ABSTRACT FROM AUTHOR]

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luorescence of natural teeth and its alterations due to environmental factors should also be taken into account in restorations. This study aims to assess fluorescence changes of three types of dental ceramics. 36 Ceramics of Feldspathic, Emax, and Enamic in 10 mm diameter and the thicknesses of 0.5 and 1mm with glaze and polish finishes were studied. Fluorescence was measured before and after aging and were analyzed using Anova test. The results showed that ceramics became opaque as the result of aging. This was more noticeable for Enamic ceramic with the lightness increase of 4.10 and 4.86 for the UV excited and non-excited measurements, respectively. Moreover, Enamic ceramic experienced significant changes in its fluorescence due to aging (Average Fluoresence ChangeEnamic=-10.2) while Emax (Average Fluoresence ChangeEmax=-3.6) and feldspathic (Average Fluoresence ChangeFeldspathic=-0.4) ceramics were superior to Enamic in this respect. In Feldspathic ceramic, due to the presence of feldspar phase, high resistance to aging process was observed. While, severe shifts in fluorescence due to aging were observed in Enamic ceramic. Several factors affect color and fluorescence change of ceramics due to aging. Preparations stresses, adhesion of glazes and the formation of micro cracks on the ceramic surfaces are among the factors can influence on this behavior. In case on Enamic ceramic caveat should be taken as it can change its appearance due to fluorescence hue shift probably as a result of surface scattering of UV light. According to the findings of this study Feldspathic, Emax and Enamic are respectively preferable in terms of fluorescence stability during aging process. [ABSTRACT FROM AUTHOR]

Objective: This in vitro study evaluated the color differences when discolored tooth substrates were restored with CAD/CAM monolithic ceramics depending on ceramic type and thickness, and the try-in paste shade. Method and materials: Six ceramic types were tested: high-translucent lithium disilicate (LD-HT); medium-translucent lithium disilicate (LD-MT); low-translucent lithium disilicate (LD-LT); low-translucent leucite (LC-LT); feldspathic ceramic (FC); and BL1 low-translucent lithium disilicate, stained to A1 shade (LD-BL1-LT). The ceramics were tested in disk-shaped specimens with 0.5-, 1.0-, and 1.5-mm thickness (n = 10; N = 180; shade A1). The try-in pastes were tested to simulate luting materials and corresponded to colors A1 and Opaque White. Six substrates were used: A1 (reference), B2, B3, A3, C2, and C3. Color differences (ΔE00) and translucency parameter (TP00) were assessed with the CIEDE2000 formula. The results were compared with acceptability (1.77) and perceptibility (0.81) thresholds. Results: Ceramic type, thickness, and the try-in paste shade influenced the color differences. LD-LT and LC-LT ceramics and Opaque White try-in paste provided, in general, lower ΔE00 values. The most adequate ceramic thickness varied according to the substrate discoloration. With 1.0 mm of ceramic thickness, it was possible to obtain ΔE00 lower than the perceptibility threshold for substrates C2 and A3, and ΔE00 lower than the acceptability threshold for C3 and B3. ΔE00 lower than the acceptability threshold were obtained with 0.5 mm of ceramic thickness for B2, A3, and C2. Conclusion: The use of low-translucent glass-ceramics and Opaque White try-in paste are useful to reduce color differences. The most adequate ceramic thickness depends on the substrate discoloration. [ABSTRACT FROM AUTHOR]

Aim: The aim of this umbrella review was to systematically review the systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. Settings and Design: This was an umbrella review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Materials and Methods: An electronic search of PubMed, Cochrane Central, EBSCOhost, and Google Scholar search engines for articles published from January 1, 2013, to January 1, 2023, was conducted using keywords “enamel wear,” “zirconia,” “feldspathic,” “dental ceramics,” and “Y-TZP” to identify systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. Statistical Analysis Used: Qualitative analysis. Results: A total of 86 articles were obtained through electronic search, of which four articles were selected after abstract screening that met the inclusion criteria for evaluating antagonist enamel wear. As compared to feldspathic groups, zirconia had substantially less antagonist wear, while surface polishing exhibited less enamel wear than glazing. Because of the heterogeneity in study design, measurement methods, and outcome variables, a meta-analysis was not possible. Conclusions: Over time, the opposing enamel wear caused by polished monolithic zirconia will be either equal to or less than that of natural enamel wear. Polished monolithic zirconia also maintains lower values of enamel wear compared to metal ceramics, feldspathic porcelains, and lithium disilicate.

Dental multilayer zirconia ceramics are attractive materials for restorative dentistry because they offer significant esthetic advantages over monolithic, white, or monocolored zirconia. They enable anatomical adjustments in dental prostheses, making them more similar to natural teeth. New categories of dental ceramics have been developed using varying translucency and color within the same piece to meet esthetic requirements. This technique employs zirconia with different yttria (Y2O3) contents to achieve varying levels of translucency. This study investigated two types of dental ceramics based on multilayer zirconia, correlating their mechanical properties, translucency, and color variations concerning their application in dental prostheses. Two types of multilayer zirconia pre-sintered blocks with different Y2O3 content were examined: 1) blocks with a Y2O3 gradient chemical composition between 3 mol.% and 4 mol.%, named M3-4YSZ; 2) blocks with a Y2O3 gradient chemical composition between 4 mol.% and 5 mol.%, named as M4-5YSZ. Samples were cut in cross-section to separate the layers based on Y2O3 content and color and were then sintered at 1530 °C for 2 h. The sintered samples were characterized by relative density, crystalline phases, microstructure, Vickers hardness, fracture toughness (KIC), and optical properties (color and contrast ratio). Fully dense ceramics were obtained after sintering. Layers containing a greater amount of Y2O3 in the zirconia matrix have a higher content of the ZrO2 cubic phase, while layers with a lower content of Y2O3 in the matrix are predominantly tetragonal ZrO2. No statistical variation in hardness was observed depending on the layers of the material. However, fracture toughness values showed significant statistical variations, with an increase in the tetragonal phase content responsible for the increase in fracture toughness. KIC in M3-4YSZ samples varied between 3.63 and 7.73 MPa.m1/2, while M4-5YSZ samples ranged from 2.70 to 5.65 MPa.m1/2. The smooth and gradual variations in color and translucency observed between the layers of the two groups of dental ceramics studied indicate stability and homogeneity between the layers, contributing significantly to esthetic effects in dental applications.

Background: Translucency and optical characteristics significantly affect the aesthetics of ceramic restorations. The introduction of new virgilite crystals to novel ceramic advanced lithium disilicate through a matrix firing process enhances the material’s strength and aesthetic quality according to the manufacturer. Materials and Methods: Four types of CAD/CAM ceramics; lithium disilicate (LD), leucite reinforced (LR), advanced lithium disilicate (ALD), and zirconia-reinforced lithium silicate (ZLS) exposed to different staining solutions (tea, cola, coffee, and distilled water). Each ceramic type had 120 specimens, divided into subgroups based on thickness (0.5 mm, 1 mm, and 1.5 mm). Color changes (ΔE00) and translucency parameters (TP00) were measured after thermocycling, and spectrophotometry was employed to evaluate ΔE00 and TP00 after 1, 7, and 30 days of exposure to the staining solutions. Results: ZLS exhibited the lowest color stability, while lithium LD and ALD displayed the highest. Thickness significantly affected color stability, with 0.5 mm thickness showing the least change. The duration of exposure also impacted color changes, with 30 days causing the most significant shift. LD demonstrated the highest translucency. Coffee and tea induced more pronounced reductions in translucency and color stability compared to the control group. Conclusions: Material structure, thickness, staining solution, and exposure duration significantly influenced the color stability and translucency of CAD/CAM ceramics, with LD and ALD demonstrating superior color stability and LD exhibiting the highest translucency.

Background: Partial coverage concepts have met the main goal of conservative dentistry. Vonlays, which combine features of veneers and onlays, are a recent alternative to full coverage designs and overlay partial coverage restorations. This in vitro study was conducted to compare the fracture resistance of the newly introduced pressable zirconia-reinforced lithium silicate with pressable lithium disilicate ceramic and to determine the optimal preparation design for partial coverage on upper premolars. Methods: Fifty-two duplicated epoxy resin dies were prepared following vonlay and overlay preparation guidelines. For each preparation (n = 26), the specimens were divided into two subgroups to be restored with lithium disilicate (IPS e.max Press) or zirconia-reinforced lithium silicate (Vita Ambria) (n = 13 each). Ceramic vonlays and overlays were bonded using dual cure resin cement, subjected to thermomechanical fatigue, and the load to fracture was tested by using a universal testing machine. The specimens were fractographically analyzed via scanning electron microscopy (SEM). The normality of the fracture resistance data was checked using the Shapiro‒Wilk test and Q‒Q plots, and two-way ANOVA was used to assess the effect of the type of preparation and ceramic material on the fracture resistance. Results: The group of overlays restored with zirconia-reinforced lithium silicate showed the highest mean fracture load (1218.69 N), while the group of vonlays restored with lithium disilicate had the lowest mean fracture resistance (967.15 N). The effect of preparation design and material type on fracture resistance was significant for both factors, p = 0.003 and p < 0.0001, respectively. Different features of the fracture surfaces, such as arrest lines, hackles, and directions of crack propagation, were observed. Conclusions: Zirconia-reinforced lithium silicate exhibited greater resistance to fracture compared to lithium disilicate, making it a potential substitute for partial coverage restorations. Additionally, the overlay showed superior fracture resistance when compared to the vonlay preparation design. [ABSTRACT FROM AUTHOR]

This review presents various interpenetrating phase composite (IPC) materials currently used in computer-aided design/computer-aided manufacturing (CAD/CAM) systems and to evaluates how the optical properties of those materials are affected by various factors. In the field of dentistry, selecting materials compatible with dental tissues is key to clinical success of restorative materials. Understanding the optical properties of a restorative material aids in material selection and provides insights into the material's clinical performance and esthetic longevity. Such knowledge can in turn help clinicians select the best treatment option for their patients. Interpenetrating phase composite materials combine the optical and mechanical properties of ceramics and composite resins; they are often used in direct/indirect restorative options such as inlays, onlays, veneers, single crowns, implant-supported crowns, and short-span fixed partial dentures with esthetically favorable outcomes. The color of a material, which plays an essential role in the esthetic outcome, can change over time depending on different intrinsic and extrinsic factors. Those intrinsic factors include chemical composition, resin-matrix structure, and filler particle sizes; extrinsic factors include surface treatment protocols, the patient's smoking status, and the consumption of beverages such as coffee, tea, red wine, fruit juice, cola, etc. To fabricate restorations that complement a person's natural teeth, it is essential to determine the color properties of these materials (e.g., translucence, hue, chroma, and opalescence). [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant‐supported single crowns with external connections under mechanical cycling. Materials and Methods: Fifty specimens were divided into groups: (1) metal–ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 106 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured. Results: The failure‐related survival rate (100%) and maximum fracture resistance of the MZrB were significantly higher than those of MC and Zr (50%; p < 0.05). There were no significant differences in the failure rate and fracture resistance when a CoCr base abutment was used or not in the translucent monolithic Zr groups (p > 0.05;MZrB vs. MZr). Failure location, with MC crowns' fractures, noted at the screw area (p = 0.043), while all‐ceramic crowns were mostly in the cuspid and to failure area, the Zr group had the largest mean (15.55 ± 9.17 mm2) among the groups, significant difference only when compared with MC (1.62 ± 0.81 mm2) (p = 0.025). Conclusions: Translucent monolithic zirconia crowns exhibited significantly higher fatigue and fracture resistance compared with conventional MC and bilayered crowns. Clinical Significance: The appropriate choice of material and manufacturing technique is crucial for predicting the higher clinical performance of single crowns. Enhanced mechanical resistance in terms of fatigue and fracture resistance can be achieved by replacing MC and bilayered restorations with computer‐aided design and computer‐aided manufacturing monolithic zirconia. [ABSTRACT FROM AUTHOR]

This study aimed to determine the crystalline phase composition of 3–6 mol% yttria-stabilized zirconia (3–6YSZ), specifically investigating the presence of tetragonal (t), cubic (c), and/or additional yttria-rich tetragonal (t') phase. Laboratory-fabricated specimens comprising 3–5YSZ, resembling translucent dental zirconia ceramics (TZ specimens), and a blend of 3YSZ and 8YSZ, representing a c -phase reference, were prepared. Additionally, 25 dental zirconia products stabilized with 3–6 mol% yttria were analyzed. Whole X-ray diffraction (XRD) patterns were obtained for Rietveld analysis, complemented by fine scanning in the 2θ region from 72º to 76º for qualitative phase analysis. Moreover, yttria concentrations in each specimen were determined using X-ray fluorescence (XRF) spectroscopy. In the 2θ region from 72º to 76º, TZ and dental zirconia product specimens displayed four peaks attributed to t - and t' -phases, but the c -phase peak was absent. Rietveld analysis of the whole XRD patterns, utilizing a t - t' model, demonstrated the t -phase fraction ranging from 86 mass% in 3YSZ to 11 mass% in 6YSZ. Rietveld analysis appeared reliable, as the yttria contents calculated based on lattice parameters aligned well with those measured by XRF. This study established that dental 3–6YSZ consisted of yttria-lean t - and yttria-rich t' -phases. The present study enhances understanding of the crystalline structure of dental zirconia ceramics. Future crystallographic analyses of these ceramics should consider the presence of t - and t' -phases. • Examined crystalline phases of 3-6 mol% yttria-stabilized zirconia. • Applied XRD and XRF for phase and chemical composition analyses. • Identified dominant yttria-lean and yttria-rich tetragonal phases. • Demonstrated the absence of cubic phase. • Improved understanding of dental zirconia's crystalline structure. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Immediate dentin sealing (IDS) was introduced to overcome the disadvantages of delayed dentin sealing like pollution of dentin tubules, microleakage, and bond strength destruction over time. The effect of IDS on the bond strength of indirect restorations is still debatable. Purpose: This study was conducted to determine the effect of IDS on the bond strength of ceramic restorations to dentin. Materials and Method: In this systematic review and meta-analysis, the study protocol was registered on the PROSPERO database under the registration number CRD420202014 27. MEDLINE (PubMed), Web of Science, Scopus, and ProQuest databases were searched until January 2021 and updated in January 2022. Worldcat.org and Opengrey.eu, ProQuest dissertation and thesis, and Google Scholar were searched to explore the grey literature. The in vitro studies evaluating the bond strength of ceramic restoration to dentin with and without IDS were included. Seven criteria were assessed to evaluate the risk of bias in the study. Statistical analyses were conducted using RevMan 5.3. The inverse variance method was used to determine the mean difference of micro-tensile bond strength (µTBS) and shear bond strength (SBS). Results: A total of 10 studies (20 datasets) were included in the meta-analysis. Regarding the µTBS analysis, IDS had a significantly higher bond strength than Delayed Dentin Sealing (DDS) (MD:1.16, 95%CI:0.28_2.03, I² =0%). However, no significant difference was found between them in the SBS analysis (MD:0.25, 95%CI: -0.56-1.06, I² =96%). All studies were categorized to have a moderate or high risk of bias. Conclusion: Most in vitro evidence showed favorable results for the effect of IDS on the bond strength and durability of indirect restorations. The adhesive system and the type of ceramic and its treatment before cementation are determining factors. Due to the heterogeneity of the outcomes and studies with a moderate/high risk of bias, the quality of the evidence was low. [ABSTRACT FROM AUTHOR]

Featured Application: This study highlights the potential application of ultra-short femtosecond lasers for modifying the surface of ceramic dental materials with high precision in a controlled manner. This study investigated the dose-dependent changes in the chemical composition of three dental ceramic materials—zirconia, lithium disilicate (LD), and VITA ENAMIC® hybrid composite (VITA En)—following irradiation with an ultra-short femtosecond (fs) laser (800 nm, 30 fs, 1 kHz) in an ambient air environment using average laser power (76 mW) and scanning speeds (50, 100, and 200 mm/s), simulating dental treatment processes. The chemical composition of the ablated regions was analyzed using energy dispersive spectroscopy. All irradiated samples showed increased carbon content (by up to 42%) and reduced oxygen (by up to 33%). The observed increase in C content is likely attributed to a combination of surface reactions, adsorption of carbon from the ambient environment, and carbon deposition from the laser-induced plasma, all facilitated by the high-energy conditions created by fs-laser pulses. Scanning electron microscopy revealed ablation with progressive controlled melting and recrystallization, with an absence of pile-up features typically associated with significant thermal damage. These findings demonstrate that ultra-short fs-laser irradiation induces highly controlled, dose-dependent changes in the chemical composition and surface morphology of dental ceramic materials. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the feasibility of monolithic zirconia laminate veneers (MZLV) compared to lithium disilicate laminate veneers (LDLV). Materials and methods: Sixty resin replicas, each prepared with depths of 0.5 mm, 0.7 mm, and 1 mm, were produced using a 3D printer from acrylic teeth. Laminate veneers of these thicknesses were milled from pre-sintered monolithic zirconia (3rd generation) and lithium disilicate blocks. The intaglio surface of MZLV was treated with air abrasion using 110 μm diameter silica-modified aluminium oxide particles and ceramic primer, while LDLV was etched with etchant gel and treated with the ceramic primer before cementation with resin cement. Vertical marginal discrepancy (VMD) was assessed using a stereomicroscope, and a load-to-failure test was conducted using a universal testing machine. Failure modes were evaluated macroscopically on fractured surfaces. Data were analysed statistically using Two-way ANOVA and Bonferroni correction (α = 0.05). Results: LDLV samples exhibited significantly larger VMD compared to MZLV samples across all thicknesses, especially in cervical, palatal, and mean data. Within the LDLV group, load-to-fracture values for 0.7 mm and 1.0 mm thicknesses were similar, whereas for 0.5 mm thickness, it was significantly lower. In the MZLV group, load-to-fracture values were lower for 0.7 mm and 1.0 mm thicknesses compared to LDLV, but higher for 0.5 mm thickness. Conclusions: Material choice and restoration thickness significantly influence laminate veneer restorations' success. MZLV generally exhibits superior vertical marginal fit compared to LDLV, with varying load-to-failure values across different thicknesses. Clinical management of debonding in MZLV is simpler compared to restoration fracture in LDLV. Clinical relevance: Considering clinical factors, MZLV may be a preferable option to LDLV for this restoration with the thickness of 0.5 mm. [ABSTRACT FROM AUTHOR]

Introduction. The utilization of ceramics in the field of dentistry has seen a significant rise owing to their esthetic appeal and excellent functional properties. The use of ceramics in the field of dentistry has witnessed a notable surge, driven by their appealing esthetics and exceptional functional attributes. Zirconia, distinguished by its exceptional mechanical strength, plays a pivotal role in the fabrication of posterior crowns and bridges. Among zirconia variants, monolithic zirconia stands out, where the entire restoration is crafted from zirconia material. In parallel, feldspathic porcelain, chosen for its remarkable resemblance to natural tooth enamel, represents another significant ceramic type. This study aims to evaluate the shear bond strength (SBS) between two types of monolithic zirconia with two types of feldspathic porcelain. Methods and Materials. Forty‐four monolithic zirconia veneered discs with feldspathic porcelain were subjected to SBS testing. The dimensions of the discs were 7 mm in diameter and 5 mm in height (3 mm of zirconia and 2 mm of porcelain). Subsequently, the specimens were subjected to a universal testing machine at a speed of 0.5 mm/min until failure occurred. The type of failure was examined using scanning electron microscopy. One‐way analysis of variance (ANOVA), two‐way ANOVA, Fisher's test, and multiple Tukey comparisons were used as statistical analyses. Results. The highest SBS was achieved by the high‐translucency monolithic zirconia with enamel porcelain group (18.81 ± 3.18 MPa) and the high‐translucency monolithic zirconia with dentin porcelain group (17.89 ± 2.75 MPa), followed by the low‐translucency monolithic zirconia with dentin porcelain group (15.04 ± 2.24 MPa) and the low‐translucency monolithic zirconia with enamel porcelain group (14.33 ± 2.00 MPa), respectively. Additionally, the most common type of failure pattern observed was mixed, followed by adhesive failure. Conclusion. The translucency of the porcelain did not significantly affect SBS, while the type of monolithic zirconia used had a significant impact. Furthermore, there was no discernible relationship between the four groups in terms of the distribution of failure patterns. [ABSTRACT FROM AUTHOR]

To evaluate the hygroscopic expansion characterization of resin composite dies during thermal cycling, and their influence on the fracture resistance of dental ceramic materials as well as the effect of pre-immersion on these measurements. Disc-shaped specimens (φ = 15.0 mm, h = 1.2 mm) and anatomical crown dies of four resin composites (epoxy, Z350, P60, G10) were fabricated. Disc-shaped samples were continuously soaked in distilled water and the volume expansion was measured at different time point by Archimedes method. Disc-shaped samples were pre-immersed for 0, 7, or 30 days, elastic modulus and hardness were measured using Nanoindentation test; thermal cycling (TC) test was performed (5 °C-55 °C, 104 cycles), and volume expansion during TC was measured. Four kinds of resin die with pre-immersion for 0, 7, or 30 days were cemented to 5Y-Z crown, or epoxy dies without pre-immersion were cemented to 5Y-Z, 3Y-Z and lithium disilicate glass (LDG) crowns, and load-to-failure testing was performed before and after TC. Finite element analysis (FEA) and fractography analysis were also conducted. The hygroscopic expansion was in the order: epoxy > Z350 > P60 > G10. Except for G10, the other three resin composites exhibited different degrees of hygroscopic expansion during TC. Only the elastic modulus and hardness of epoxy decreased after water storage. However, only the fracture loads of 5Y-Z and LDG crowns supported by epoxy dies were significantly decreased after TC. FEA showed a stress concentration at the cervical region of the crown after volume expansion of the die, leading to the increase of the peak stress at the crown during loading. Significance : Only the hygroscopic expansion of epoxy dies caused by TC led to the decrease in the fracture resistance of the 5Y-Z and LDG crown, which may be related to the decrease in the elastic modulus of the epoxy die and the tensile stress caused by it. • The hygroscopic expansion of resin dies during thermal cycling decreases the fracture load of their supported ceramic crowns. • The susceptibility of hygroscopic expansion is related to the elastic modulus and the filler/matrix ratio of the resin die. • Pre-immersion of the resin dies could reverse their hygroscopic expansion effect on the supported crown. [ABSTRACT FROM AUTHOR]

Background: Osseointegration is fundamental to achieving successful implant therapy in dentistry. However, the heat generated during implant placement emerges as a critical factor predisposing to implant failure. Objective: This study aimed to analyze the different factors related to heat generation during implant placement, offering insights to clinicians in their daily clinical practice. Methods: Utilizing the PubMed, Web of Science, and Embase databases, we conducted an electronic search for articles published between January 2013 and December 2023. The analysis focused on several factors including bone type, drill shape, drill speed, drill material, drilling force, osteotomy depth, drill load, drilling technique (intermittent or continuous), presence of a surgical guide, irrigation methods, drill wear, and preparation tools available. Results: Initially, 2525 records were identified. After applying the inclusion and exclusion criteria and full-text assessment, 93 articles were included in this scoping review. Additionally, some articles published before 2013 were incorporated in the bibliography to ensure completeness of the review. Conclusions: Heat generation during implant placement arises from a complex interplay of multiple factors. While irrigation and bone hardness appear to be crucial determinants of heat generation during the osteotomy phase, the involvement of other factors remains less clear. Further studies are needed to better understand the precise contribution of these factors towards increasing temperature at the implant site. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of different veneering ceramics and veneering techniques on the bond strength to zirconia. Materials and Methods: 3Y‐TZP zirconia blocks were sliced into 60 slabs, polished, and sintered. Each slab received one ceramic cylinder (Ø = 3.4 mm, 5 mm‐high), according to the veneering ceramic type (feldspathic—FEL or lithium disilicate‐based—LD) and the veneering technique (file‐splitting with resin‐based luting agent—RC, file‐splitting with fusion ceramic—FC, or heat‐pressing—HT), which resulted in six groups: FEL‐RC, FEL‐FC, FEL‐HT, LD‐RC, LD‐FC, LD‐HT. After preparation, the samples were immersed in distilled water for 24 h before the shear bond strength (SBS) test. The failure modes were classified as adhesive, predominantly adhesive, or cohesive. Representative failure mode images were taken in a Scanning Electron Microscope. The SBS data were analyzed by two‐way ANOVA and Tukey's test. Results: Both type of veneering ceramic and technique affected the bond strength. FC led to the highest SBS values. RC and HP provided similar results when compared within each veneering ceramic. Lithium disilicate achieved lower bond strength than feldspathic ceramic when the heat‐pressing technique was applied. The most frequent failure modes were predominantly adhesive and adhesive for FEL and LD, respectively. Conclusion: File‐splitting with fusion ceramic provided the highest adhesion to zirconia when feldspathic or lithium disilicate‐based ceramics were used. The heat‐pressing technique for veneering with lithium disilicate significantly decreased the bond strength when compared to the feldspathic ceramic. [ABSTRACT FROM AUTHOR]