Search Results (76)

Background: CAD/CAM dental ceramics are widely used for indirect restorations because of their favorable esthetic properties, biocompatibility, and mechanical performance. However, long-term exposure to thermal fluctuations, moisture, and cyclic loading may compromise their structural integrity. This systematic review and meta-analysis evaluated the effect of artificial aging protocols on the mechanical properties of CAD/CAM dental ceramics. Methods: A systematic search was conducted in PubMed, Embase, Scopus, Web of Science, LILACS, Google Scholar, and ProQuest from inception to June 2026. In vitro studies evaluating CAD/CAM ceramics subjected to thermocycling and/or artificial aging protocols were included. The primary outcomes were flexural strength and fracture resistance. Random-effects meta-analyses were performed using standardized mean differences (SMDs) or pooled means with 95% confidence intervals (CIs). Subgroup analyses were conducted according to ceramic category, and sensitivity analyses were performed using a leave-one-out approach. Results: Five studies comprising 16 independent comparisons were included in the flexural strength meta-analysis, while five studies contributed 11 comparisons to the fracture resistance analysis. Artificial aging protocols significantly reduced the flexural strength of CAD/CAM ceramics (SMD = −1.68; 95% CI: −2.28 to −1.08; p < 0.00001). The greatest reduction was observed in zirconia-based ceramics (SMD = −3.31), followed by hybrid/PICN ceramics (SMD = −1.37) and lithium disilicate/lithium silicate ceramics (SMD = −1.25). Feldspathic and glass-based ceramics showed no significant reduction. The pooled fracture resistance after aging was 1312.85 N (95% CI: 1131.59–1494.10 N), indicating that most CAD/CAM ceramics maintained clinically relevant fracture resistance despite aging. Conclusions: Artificial aging protocols adversely affect the flexural strength of CAD/CAM dental ceramics, particularly zirconia-based materials. Nevertheless, fracture resistance generally remains within clinically acceptable ranges. Material composition plays a critical role in determining susceptibility to aging-related degradation, highlighting the importance of ceramic selection for long-term restorative performance. Full article

This study evaluated the effects of restorative material, restoration type, and fiber strip reinforcement on the fracture strength (FS) of endocrown (EC) and post-core (PC) restorations in endodontically treated premolars. Specimens were allocated according to restorative material [resin-nanoceramic (RNC) or feldspathic ceramic (FC)], restoration type (EC or PC), and reinforcement [fiber strip-reinforced (FR) or -non-reinforced (NF)]. FS was determined using a universal testing machine under axial loading. Statistical analysis was performed using three-way ANOVA and Bonferroni tests (α = 0.05). Material, restoration type, and reinforcement significantly affected FS (p < 0.05). RNC restorations exhibited higher FS than FC restorations (861 ± 181 N vs. 715 ± 212 N; p < 0.001). EC restorations exhibited higher FS than PC restorations (828 ± 173 N vs. 748 ± 236 N; p = 0.046). FR groups exhibited higher FS than NF groups (848 ± 180 N vs. 728 ± 222 N; p = 0.003). The highest FS was observed in the RNC–PC–FR group (965 ± 144 N), whereas the lowest occurred in the FC–PC–NF group (480 ± 177 N). Although EC restorations showed higher FS than PC restorations, the effect of restoration type depended on material and reinforcement. Full article

Background: This study aimed to investigate the biomechanical behavior of conservative inlay restorations fabricated from different CAD/CAM materials by combining experimental flexural strength testing with finite element analysis. Methods: Five CAD/CAM materials were evaluated: feldspathic ceramic (Cerec Blocs), leucite-reinforced ceramic (IPS Empress CAD), resin nano-ceramic (Lava Ultimate), polymer-infiltrated ceramic network (VITA Enamic), and lithium disilicate ceramic (IPS e.max CAD). Young’s modulus and Poisson’s ratio were experimentally determined using three-point bending and nanoindentation tests and used as inputs for 3D FEA. Von Mises (VM) stress distributions within the inlays were analyzed under simulated occlusal loading. Results: Maximum VM stresses showed an inverse relationship with material elasticity. IPS e.max CAD exhibited the highest maximum VM stress (45.571 MPa), whereas the resin nano-ceramic showed the lowest (25.419 MPa). Despite higher stress concentrations in high-modulus ceramics, VM values for all materials remained well below their FS limits. Conclusions: All materials demonstrated adequate mechanical stability under physiological loading. Lithium disilicate showed a comparatively larger margin between stress levels and flexural strength, while lower-modulus materials tended to promote greater stress transfer to supporting structures. Full article

The long-term esthetic performance of indirect restorations is closely related to the color stability and surface integrity of the restorative materials used. With the increasing use of CAD/CAM technologies, a wide range of ceramic- and resin-based materials have been developed for indirect restorative applications. These include feldspathic ceramics (VITA Mark II, VITA Zahnfabrik), hybrid ceramics (VITA Enamic, VITA Zahnfabrik), resin nanoceramic CAD/CAM blocks (Lava Ultimate, 3M), and indirect microhybrid resin composites (GC Posterior, GC Corporation). However, these materials are continuously exposed to chemical and mechanical challenges in the oral environment, such as staining from beverages and daily toothbrushing, which may compromise their optical and surface properties over time. The purpose of this in vitro study was to evaluate and compare the color change (ΔE) and surface roughness (Ra) of these materials after repeated coffee immersion and simulated toothbrushing. A total of 240 disk-shaped specimens were fabricated and subjected to three aging cycles consisting of storage in coffee or distilled water, followed by simulated toothbrushing with or without toothpaste. The color parameters were measured using a spectrophotometer according to the CIE Lab* system, surface roughness was assessed using a contact profilometer, and surface topography was qualitatively analyzed by atomic force microscopy. The results demonstrated that coffee immersion significantly increased both color change and surface roughness for all tested materials, with more pronounced effects observed in resin-based materials. Ceramic-based CAD/CAM materials (VITA Mark II and VITA Enamic) showed greater resistance to discoloration and surface degradation, whereas the resin nanoceramic material (Lava Ultimate) and the microhybrid resin composite (GC Posterior) exhibited clinically perceptible color changes and higher roughness values, particularly after toothbrushing with toothpaste. Full article

Background/Objectives: This systematic review aimed to quantify the extent of wear of opposing posterior natural enamel in patients with single-unit ceramic crowns. Methods: A comprehensive search was conducted in PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, and ProQuest through September 2025. A meta-analysis was performed using the inverse variance method. Results: Nine clinical studies (5 randomized controlled trials and 4 prospective studies) involving 203 patients (2015–2025) were included. All studies evaluated monolithic zirconia; two also assessed monolithic lithium disilicate, and three included metal-ceramic restorations with feldspathic veneering. Follow-up ranged from 6 to 24 months. Meta-analysis revealed significant enamel wear from zirconia (p < 0.05; MD: −1.32; 95% CI: −2.06 to −0.57; I² = 94%) and lithium disilicate (p < 0.05; MD: −0.45; 95% CI: −0.71 to −0.19; I² = 2%). Feldspathic ceramics did not show significant enamel wear (p = 0.06; MD: −2.77; 95% CI: −5.66 to 0.13; I² = 96%). Conclusions: Ceramic materials generally cause greater wear on opposing posterior natural enamel than enamel-to-enamel contact. Monolithic zirconia and lithium disilicate crowns produced higher antagonist wear, whereas metal-ceramic restorations with feldspathic veneering appeared more conservative for preserving posterior enamel. Full article

Background/Objectives: There is evidence of possible contamination of prosthetic components originating from dental laboratories. The aim of this study is to investigate the disinfectant effect of citric acid and polyethylene glycol on implant-prosthetic materials in comparison with an untreated control and chlorhexidine. Methods: A total of 720 disks made of three different materials (titanium grade V, zirconia coated with feldspathic ceramic, and PMMA) contaminated with three bacteria (Staphylococcus aureus, Enterococcus faecalis, and porphyromonas gingivalis) were analyzed. Four treatment groups were tested: citric acid, polyethylene glycol, chlorhexidine and an untreated control group. Two assessment periods (3 and 21 days of incubation) were used, with bacterial metabolic activity measured using the resazurin reduction test and then analyzed by electron microscopy. Results: The results show that chlorhexidine has a superior inhibitory effect on all materials and bacterial strains in the short-term evaluation (3 days), while citric acid and polyethylene glycol showed higher efficacy after 21 days. Citric acid also exhibits differential effects when applied to grade V titanium. These differences were statistically significant at p < 0.05. Conclusions: There is evidence to recommend chlorhexidine for the disinfection of laboratory prosthetic components, but the enhanced effect of citric acid on grade V titanium and its long-term efficacy make it clinically promising candidate. Full article

Aim: This study aimed to evaluate and compare the surface properties, roughness, skewness, and wettability of three CAD/CAM-processed ceramic materials: zirconia-reinforced lithium silicate (Celtra Duo), feldspathic ceramic (CEREC Blocs), and lithium disilicate (CEREC Tessera). Materials and Methods: Thirty specimens (10 per group) were fabricated (10 × 10 × 2 mm) using the CEREC Omnicam AC system with the MC XL milling unit and SpeedFire furnace. Surface characterization included computed tomography (CT) for dimensional accuracy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) for microstructure and composition, profilometry for roughness parameters (Ra, Rq, Rsk), and contact angle measurements with water, ethylene glycol, and diiodomethane for wettability. Statistical analysis was performed using ANOVA (p < 0.05). Results: No dimensional or compositional changes occurred after processing. Mean Ra values were 2.8647 µm for lithium disilicate, 1.9715 µm for zirconia-reinforced lithium silicate, and 1.9148 µm for feldspathic ceramic. All materials exhibited negative skewness, with zirconia-reinforced lithium silicate showing the smoothest morphology. Contact angle results indicated greater hydrophilicity for lithium disilicate (31.41°), followed by feldspathic ceramic (38.31°) and zirconia-reinforced lithium silicate (42.48°). Conclusions: Zirconia-reinforced lithium silicate demonstrated a favorable combination of surface topography, roughness, and wettability, suggesting superior long-term clinical performance. Full article

Objective: To investigate the effect of various surface conditioning protocols on the shear bond strength between 3D-printed dental composite resin and feldspathic ceramic rods using Panavia V5 resin cement. Methods: 3D-printed composite resin discs were allocated into four groups based on surface treatment: (1) untreated control, (2) air abrasion, (3) hydrofluoric acid etching, and (4) combined air abrasion and hydrofluoric acid etching. All specimens were bonded to standardized Vita Mark II ceramic rods using Panavia V5 cement under a static load to ensure uniform cement thickness, followed by light curing using an LED unit at 1200 mW/cm² for 20 s. After 24 h of water storage at 37 °C, shear bond strength was evaluated using a universal testing machine. Statistical analysis was performed using one-way ANOVA and Tukey’s post-hoc test (α = 0.05). Results: The combined treatment group demonstrated the highest mean bond strength (40.7 ± 11.5 MPa), followed by the hydrofluoric acid group (37.8 ± 9.3 MPa). Both groups exhibited significantly higher bond strength compared to the untreated control (p = 0.002 and p = 0.011, respectively), with no statistically significant difference between them (p = 0.887). The air abrasion-only group did not differ significantly from the untreated control (p = 0.570). Conclusions: Hydrofluoric acid etching, either alone or in combination with air abrasion, significantly enhances the shear bond strength between 3D-printed composite resin and feldspathic ceramic substrates. Air abrasion alone did not result in a significant improvement compared to the untreated condition. Full article

This study investigates the potential of residual clays from a traditional ceramic-producing region in southern Portugal as raw materials for red ceramic applications. This work aims to support more sustainable ceramic practices through the local valorization of naturally available, underutilized clay resources. A multidisciplinary approach was employed to characterize clays, integrating mineralogical (XRD), chemical (XRF), granulometric, and thermal analyses (TGA/DTA/TD), as well as technological tests on plasticity, extrusion moisture, shrinkage, and flexural strength. These assessments were designed to capture both the intrinsic properties of the clays and their behavior across key ceramic processing stages, such as shaping, drying, and firing. The results revealed a broad diversity in mineral composition, particularly in the proportions of kaolinite, smectite, and illite, which strongly influenced plasticity, water demand, and thermal stability. Clays with higher fine fractions and smectitic content exhibited excellent plasticity and workability, though with increased sensitivity to drying and firing conditions. Others, with coarser textures and illitic or feldspathic composition, demonstrated improved dimensional stability and lower shrinkage. Thermal analyses confirmed expected dehydroxylation and sintering behavior, with the formation of mullite and spinel-type phases contributing to densification and strength in fired bodies. This study highlights that residual clays from varied geological settings can offer distinct advantages when matched appropriately to ceramic product requirements. Some materials showed strong potential for direct application in structural ceramics, while others may serve as additives or tempering agents in formulations. These findings reinforce the value of integrated characterization for optimizing raw material use and support a more circular, resource-conscious approach to ceramic production. Full article

Background: This study investigated a new multi-acid-etching formulation for zirconia ceramics, containing hydrochloric, hydrofluoric, nitric, orthophosphoric, and sulfuric acids. The solution was tested on polycrystalline (5Y-TZP zirconia), lithium disilicate, hybrid ceramic, and feldspathic porcelain to assess compatibility, etching selectivity, and surface conditioning. Methods: Two-hundred-and-forty CAD/CAM specimens were etched for 20 s, 60 s, 30 min, or 1 h, and their surface roughness and etching patterns ware evaluated using 3D optical profilometry and scanning electron microscopy (SEM). Results: A positive correlation was observed between etching time and surface roughness (Ra values). The most pronounced changes were observed in lithium disilicate and feldspathic porcelain, with Ra values increasing from 0.733 ± 0.082 µm (Group 5) to 1.295 ± 0.123 µm (Group 8), and from 0.902 ± 0.102 µm (Group 13) to 1.480 ± 0.096 µm (Group 16), respectively. Zirconia increased from 0.181 ± 0.043 µm (Group 1) to 0.371 ± 0.074 µm (Group 4), and the hybrid ceramic from 0.053 ± 0.008 µm (Group 9) to 0.099 ± 0.016 µm (Group 12). Two-way ANOVA revealed significant effects of material and etching time, as well as a significant interaction between the two factors (p < 0.001). SEM observation revealed non-selective etching pattern for the lithium disilicate groups, indicating a risk of over-etching. Conclusions: The tested etching solution increased surface roughness, especially for the lithium disilicate and feldspathic porcelain specimens. In zirconia, one-hour etching improved surface characteristics with minimal observable damage. However, additional studies are necessary to validate the mechanical stability and bond effectives of this approach. Full article

Background/Objectives: Anterior dental trauma in adolescents presents complex restorative challenges due to ongoing craniofacial development and high aesthetic expectations. This study evaluated the long-term clinical performance of feldspathic ceramic veneers and lithium disilicate crowns used in the anterior region following dental trauma in adolescents. Methods: A total of 209 restorations were placed in 85 adolescents (50 females, 35 males), aged 11.1–17.9 years (mean age: 15.1 years). Of these, 144 were lithium disilicate crowns, and 65 were feldspathic ceramic veneers. All restorations were fabricated using minimally invasive protocols and followed up for periods ranging from 3 to 60 months. Outcomes were assessed based on standardized clinical criteria for success and failure. Results: Lithium disilicate crowns exhibited superior long-term performance, with the majority of failures occurring in feldspathic veneers (p < 0.001), primarily due to chipping or structural fracture. Age and gender had no statistically significant influence on failure rates. Conclusions: Both feldspathic and lithium disilicate ceramic restorations represent viable treatment options for anterior dental trauma in adolescents. However, lithium disilicate demonstrates greater mechanical reliability, particularly in teeth with significant hard tissue loss. These results support the use of durable ceramic materials in adolescent restorative protocols involving dental trauma. Full article

Background and Objectives: Conventional methods for removing cemented fixed prosthetic restorations (FPRs) are unreliable and lead to unsatisfactory outcomes. At their best, they allow the tooth to be saved at the expense of a laborious process that also wears down rotating tools and handpieces and occasionally results in abutment fractures. Restorations are nearly never reusable in any of these situations. Erbium-doped yttrium-aluminum-garnet (Er:YAG) and erbium-chromium yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers casafely and effectively remove FPRs, according to scientific studiesre. This study sets out to examine the impact of Er:YAG laser radiation on the debonding of different ceramic restorations, comparing the behavior of various ceramic prosthetic restoration types under laser radiation action and evaluating the integrity of prosthetic restorations and dental surfaces exposed to laser radiation. Materials and Methods: The study included a total of 16 removed teeth, each prepared on opposite surfaces as abutments.y. Based on the previously defined groups, four types of ceramic restorations were included in the study: feldspathic (F), lithium disilicates (LD), layered zirconia (LZ), and monolithic zirconia (MZ). The thickness of the prosthetic restorations was measured at three points, and two different materials were used for cementation. The Er:YAG Fotona StarWalker MaQX laser was used to debond the ceramic FPR at a distance of 10 mm using an R14 sapphire tip with 275 mJ, 20 Hz, 5.5 W, with air cooling (setting 1 of 9) and water. After debonding, the debonded surface was visualized under electron microscopy. Results: A total of 23 ceramic FPRs were debonded, of which 12 were intact and the others fractured into two or three pieces. The electron microscopy images showed that debonding took place without causing any harm to the tooth structure. The various restoration types had the following success rates: 100% for the LZ and F groups, 87% for the LD group, and 0% for the MZ group. In terms of cement type, debonding ceramic FPRs cemented with RELYX was successful 75% of the time, compared to Variolink DC’s 69% success rate. Conclusions: In summary, the majority of ceramic prosthetic restorations can be successfully and conservatively debonded with Er:YAG radiation. Full article

Background: Aesthetic dentistry increasingly demands minimally invasive, predictable, and patient-centered solutions. Digital technologies and AI-driven planning tools are now integral to interdisciplinary treatments. Aim: To evaluate, by means of a 16-item questionnaire, patients’ perceptions of smile aesthetics and oral function before and after receiving clear aligner therapy followed by minimally invasive ceramic veneers, using digital planning and Smile Creator software. Materials and Methods: Five adult patients underwent digital smile design, clear aligner therapy, and feldspathic veneer placement. Pre- and post-treatment perceptions of smile aesthetics and function were assessed using a structured questionnaire. AI-based simulation tools (2D and 4 K TruSmile video previews) were incorporated. Paired t-tests were used to compare outcomes before and after treatment. Results: Mean pre-treatment scores were 4.8 for smile aesthetics and 6.6 for function. Post-treatment scores significantly improved to 9.8 (p = 0.001) and 9.4 (p = 0.002), respectively. Patients rated AI-generated smile previews more favorably than 2D designs and acknowledged the value of digital tools in understanding and accepting treatment. Conclusions: The integration of digital and AI-based tools in aesthetic dentistry enhances patient communication, improves predictability, and enables minimally invasive treatment. Patient satisfaction was high, underscoring the effectiveness of the combined orthodontic and prosthetic approach. Full article

Background and Objectives: Ensuring the optimal shear bond strength (SBS) is essential for the long-term success of prosthodontic restorations. Our in vitro study aimed to evaluate the SBS of three types of ceramics (feldspathic, alumina, and lithium disilicates) using three adhesive cements (Variolink Esthetic LC, Variolink Esthetic DC, and Maxcem Elite). Materials and Methods: Healthy molars were prepared, and ceramic blocks were cemented following universally accepted luting protocols. SBS tests were performed using a custom-made testing machine. A multiple linear regression model assessed the effects of ceramic type, surface treatment, and luting agent on SBS. Results: The regression model explained 61.3% of the variation in SBS values (R² = 0.613); the adjusted R² = 0.605 confirmed the model’s robustness. The global F-test was statistically significant (F = 78.96, p < 0.001). The total-etch technique (+4.47), the use of feldspathic ceramic, and 5% hydrofluoric acid treatment (+3.28) significantly affected SBS. Feldspathic ceramic and lithium disilicate showed superior performance against alumina. Light-cured and self-cured cement showed negative effects. Conclusions: Ceramic material and cement type have combined effects on SBS. Optimal results were obtained with the total-etch technique, feldspathic ceramic, 5% hydrofluoric acid treatment, and dual-cured cement. Full article

Additive manufacturing (AM) of ceramics presents a promising approach for the production of complex sanitaryware prototypes, offering advantages in terms of cost and time to market. This study explores binder jetting (BJ) as an optimal AM technique due to its ability to process ceramic materials without thermal stress, accommodate various compositions, and produce large components without support structures. A combination of refractory cement, feldspathic sands, quartz, and calcined alumina was used to formulate 19 different compositions, ensuring adequate green strength and minimizing shrinkage during sintering. A hydration-activated binding method with a water-based binder was employed to enhance part formation and mechanical properties. The results indicate that compositions containing calcined alumina exhibited lower pyroplastic deformation, while optimized gelling agent concentrations improved green strength and dimensional accuracy. The final selected material (SA18) demonstrated high compressive strength, low shrinkage, and a surface roughness comparable to traditional sanitaryware. The application of an engobe layer improved glaze adherence, ensuring a homogeneous surface. This study highlights binder jetting as a viable alternative to traditional ceramic processing, paving the way for its adoption in industrial sanitaryware manufacturing. Full article