Search Results (37)

Using multifunctional dual-cure smart bioactive resin luting agents (DRLs) offers benefits in adhesive dentistry, but their optical stability remains a concern. Their pre-cured form is a shear-thinning structure with thixotropic gel-like behavior. The effect of their hydrophilicity and different thicknesses of nanoceramic hybrid on the final shade of milled esthetic restorations needs further investigation. This study examined how the optical function deterioration of dual-cure smart bioactive resin luting agents used to bond a CAD/CAM nano-ceramic hybrid composite would influence the restoration’s final shade at three different thicknesses. A nanoceramic hybrid composite (GD) was cut into blocks and grouped by thickness (0.8, 1.0, 1.5 mm). Ten blocks from each group were assigned to subgroups based on the DRL type: Panavia SA Universal (PN), Predicta Bioactive (PR), and ACTIVA BioACTIVE (AC). Color and whiteness changes after a 24 h/day (24 days) coffee immersion were analyzed using statistical methods (ANOVA and Tukey’s HSD for ΔE₀₀; Welch’s ANOVA and Games-Howell for ΔWI_D and ΔL*). DRL type significantly affected ΔE₀₀, ΔWI_D, and ΔL* (p < 0.001). All materials showed the least color change and optical function deterioration at a restoration thickness of 1.5 mm, which was below the acceptability threshold (AT). Despite PR’s bioactive functionality, it maintained its primary optical function with the least color change at GD thicknesses of 1.0 and 1.5 mm (p < 0.001). AC exhibited the greatest ΔE₀₀ above AT, especially at a thickness of 0.8 mm (p < 0.001). ΔL*, ΔE₀₀, and ΔWI_D varied significantly based on DRL type, GD thickness, and the interaction between DRL and thickness (p < 0.05). This suggests that although dual-cure smart DRLs containing bioactive glasses are advantageous, their optical function shifts may become more noticeable in thin, translucent restorations. Increasing the restoration thickness can help mitigate this by altering the optical pathway. Full article

The enamel of teeth affected by Molar–Incisor Hypomineralization (MIH) has been reported to have a higher protein content. Though a glass hybrid is recommended for restoring teeth with MIH in children, there is a lack of in vitro research on the influence of deproteinization on its marginal integrity. Therefore, this study aimed to evaluate whether enamel pretreatment with 5.25% NaOCl reduces the size of the marginal crevice of such restorations. Out of eight extracted teeth with severe MIH, restored using a glass hybrid (Equia Forte HT/GC), half underwent deproteinization. A stereoscopic and a scanning electron microscope (SEM) were used for sections analysis. The median value of the marginal crevice measured using stereoscopic microscopy (n = 17) was significantly lower for the deproteinized (6.78 μm) than for the standard-prepared specimens (12.61 μm), p = 0.008. On SEM images, the median marginal crevice (n = 10) was 69.40 μm versus 156.77 μm for the deproteinized and standard groups, respectively. The differences, however, were not statistically significant. This study only partially confirmed the hypothesis that pretreatment with NaOCl reduces marginal crevices between the Equia Forte HT material and hypomineralized hard tissues. Further studies on the effect of deproteinization on the marginal adaptation of glass hybrid materials are needed. Full article

This study aimed to evaluate the effect of popular beverages, coffee, matcha, and protein isolate, on the microhardness and color stability of feldspar glass ceramic (VB) and nano-ceramic hybrid composite (GD) CAD/CAM materials. Three hundred specimens were prepared and divided into control and immersion groups (water, coffee, matcha, protein). Vicker’s microhardness (HN) was recorded for the control group and post-immersion groups, while color changes were measured before and after immersion. Microhardness values (HN) and color change (ΔE00) were statistically analyzed using the Kruskal–Wallis test followed by Dunn’s post hoc test (p < 0.05). Results: The HN values of all VB and GD immersion subgroups were significantly lower than those of the control groups (p < 0.001). The VB water immersion group had a significantly lower HN than the protein and matcha immersion groups. The GD immersion groups showed no significant difference in HN between them (p > 0.05). VB had a significantly lower ΔE00 (>3.5) and higher HN (790.8 ± 123.62 kgf/mm²) than GD (175.22 ± 28.95 kgf/mm²) (p < 0.001). Coffee caused the greatest ΔE00 in both VB and GD, whereas protein caused the lowest ΔE00 in GD. Conclusion: The study revealed that the feldspar glass ceramic CAD/CAM material had higher microhardness and color stability than the nano-ceramic hybrid composite. Immersion reduces the microhardness and color stability of CAD/CAM ceramics. Matcha and protein have less impact on glass ceramic microhardness, with protein causing less discoloration in nano-ceramic hybrid composites than other immersion media. Full article

This systematic review aimed to evaluate the effect of laser surface treatment on the bond strength of adhesive restorative materials to primary teeth. A comprehensive literature search was conducted in PubMed, Scopus, Embase, Web of Science and WorldCat up to July 2025 using the keywords primary teeth, deciduous teeth, milk teeth, laser, adhesion, bond strength. Twenty-six studies met the inclusion criteria, including 22 shear bond strength (SBS), three microtensile bond strength (µTBS) and one microshear bond strength (µSBS) investigations. Most studies evaluated erbium lasers (Er:YAG, Er,Cr:YSGG), while fewer assessed diode, Nd:YAG or KTP devices. In dentin, erbium lasers at low-to-moderate energy levels consistently produced smear-free, micro-retentive surfaces with open tubules and bond strengths comparable to bur-prepared controls. High-energy irradiation, however, frequently caused microcracks, tubule collapse and reduced adhesion. In enamel, phosphoric acid etching remained the most effective conditioning method, although combined laser–acid pretreatment often improved bonding of sealants and composites. Material-dependent effects were also evident: resin composites generally outperformed glass ionomers, hybrids and bioactive restorative materials. Phosphoric acid etching remains indispensable for enamel conditioning, while dentin benefits from carefully controlled erbium laser irradiation in combination with suitable adhesive systems. Full article

Background/Objectives: The marginal adaptation of CAD/CAM restorations remains a key determinant of long-term clinical success, particularly in minimally invasive preparations. This in vitro study evaluated and compared the marginal gap of three CAD/CAM restorative materials—Cerasmart, G-CAM, and IPS Empress CAD—using standardized preparation and SEM measurement protocols. Methods: A total of 18 crowns were fabricated, of which 9 presented margins sufficiently interpretable under SEM and were included in the pooled quantitative analysis (n = 362 measurement points). Marginal gaps were recorded at 45×, 100× and 450× magnification using a Jeol JSM 25S scanning electron microscope. Normality and variance homogeneity were verified prior to parametric testing. Results: When pooled per material group, the mean ± SD marginal gap values were 18.53 ± 14.15 µm for Cerasmart, 21.60 ± 14.89 µm for G-CAM, and 47.09 ± 16.93 µm for IPS Empress CAD. All values fell below the contemporary clinical threshold of <70 µm for adhesive cementation. Pairwise comparison showed a large difference between IPS Empress CAD and the two resin-based materials, whereas the difference between Cerasmart and G-CAM was small. Conclusions: Hybrid and resin nano-ceramic CAD/CAM materials demonstrated narrower marginal gaps compared with the glass ceramic tested, likely due to their lower elastic modulus and greater seating accommodation during cementation. Within the limits of this in vitro design, all materials exhibited marginal adaptation consistent with current clinical acceptability criteria. Full article

BioFlx crowns represent an innovative hybrid resin polymer-based alternative for pediatric full-coverage restorations, addressing the clinical dilemma between durable-but-unaesthetic stainless steel crowns (SSCs) and technique-sensitive zirconia crowns. This narrative review synthesizes current evidence of BioFlx crowns’ mechanical properties, clinical performance, and material characteristics through a comprehensive literature search across PubMed, Scopus, and Web of Science from August through September 2025. The search identified 18 studies comprising four randomized controlled trials, two case reports/series, and twelve in vitro studies. In vitro analyses demonstrated favorable stress distribution under physiological loads (≤311 N) with notable brand-dependent performance variations. NuSmile BioFlx exhibited greater wear than zirconia, but superior wear resistance compared to SSCs, while Kids-e-Dental BioFlx crowns demonstrated less crown wear relative to zirconia, with both brands causing less antagonist wear than zirconia. BioFlx showed intermediate fracture resistance, comparable surface roughness to SSCs but higher than zirconia, and intermediate marginal gaps. Resin cements demonstrated superior retention compared to manufacturer-recommended glass ionomer and resin-modified glass ionomer cements. Clinical studies with a 12 month follow-up demonstrated 92–98% retention rates compared to 100% for SSCs, with significantly higher patient satisfaction and reduced plaque accumulation versus SSCs. However, a failure rate of 6.7% was observed. Color change values were lower than those of zirconia crowns; however, they remained clinically unacceptable (ΔE > 3.3), and stain resistance was lower than that of SSCs. Marginal integrity remained clinically acceptable, though some anatomic form deterioration occurred over time. Case reports highlighted clinical utility in nickel-allergic patients and for masking silver diamine fluoride discoloration. BioFlx crowns represent a clinically valuable esthetic alternative in pediatric dentistry, though evidence remains limited by recent market introduction, brand-specific performance variations (NuSmile vs. Kids-e-Dental), anterior tooth applicability constraints, and contraindications in bruxism and for the Hall technique. Future randomized controlled trials with ≥2 year follow-up periods are imperative to establish long-term performance. Until such evidence emerges, BioFlx crowns represent a viable clinical option for esthetically sensitive cases and nickel-allergic patients when applied with rigorous case selection. Full article

Background: We evaluated the immediate and artificially aged micro-tensile bond strengths (μTBS) of Hi-Bond Universal, a universal adhesive containing mesoporous bioactive glass (MBG). Methods: Human dentin specimens were bonded using the following four application modes: Hi-Bond Universal in etch-and-rinse mode, Hi-Bond Universal in self-etch mode, Single Bond 2 in etch-and-rinse mode, and G-ænial Bond in self-etch mode. Specimens were tested either immediately or after artificial aging (thermocycling or water storage). μTBS values were analyzed statistically, and the resin–dentin interfaces were examined using FE-SEM (Field-emission scanning electron microscopy). Results: Results showed that both aging and adhesive mode significantly affected the μTBS (p < 0.0001). Immediately after bonding, etch-and-rinse modes produced significantly higher μTBS than the self-etch modes (p < 0.0001). Artificial aging reduced bond strength by approximately 30–50%; however, the μTBS of Hi-Bond Universal decreased less than that of Single Bond 2 after water storage. FE-SEM analysis also revealed detachment of the hybrid layer in most adhesives following aging; however, Hi-Bond Universal in the etch-and-rinse mode maintained a relatively intact adhesive layer after water storage. Conclusion: Etch-and-rinse application of MBG-containing adhesive may enhance the long-term durability of adhesive restorations. Full article

The growing challenge of biofilm-associated infections in dentistry necessitates advanced solutions. This review highlights the potential of smart bioactive and antibacterial materials—bioactive glass ceramics (BGCs), silver nanoparticle (AgNP)-doped polymers, and pH-responsive chitosan coatings—in transforming restorative dentistry. BGCs reduce biofilms by >90% while promoting bone integration. AgNP-polymers effectively combat S. mutans and C. albicans but require controlled dosing (<0.3 wt% in PMMA) to avoid cytotoxicity. Chitosan coatings enable pH-triggered drug release, disrupting acidic biofilms. Emerging innovations like quaternary ammonium compounds, graphene oxide hybrids, and 4D-printed hydrogels offer on-demand antimicrobial and regenerative functions. However, clinical translation depends on addressing cytotoxicity, standardizing antibiofilm testing (≥3-log CFU/mL reduction), and ensuring long-term efficacy. These smart materials pave the way for self-defending restorations, merging infection control with tissue regeneration. Future advancements may integrate AI-driven design for multifunctional, immunomodulatory dental solutions. Full article

To improve the reliability of glass-fiber/epoxy-reinforced polymer (GFRP) composites, four laminates were manufactured by vacuum bagging: (i) a virgin baseline, (ii) an epoxy system modified with 15 wt% high-density polyethylene (PE) powder, (iii) a laminate interleaved with electrospun polyacrylonitrile (PAN)-based nanofiber mats, and (iv) a hybrid combining both modifiers. The specimens were subjected to low-velocity impacts; half were then heated at 150 °C for 30 min and re-impacted. PE caused peak-load loss up to 30% compared to virgin specimens but recovered 25% after heating by filling cracks. PAN interleaves limited the loss to 5%, and the hybrid laminate merged the benefits: it showed the highest first-impact load, retained 96% on re-impact, and gained a further 10% after heating while keeping the smallest permanent indentation. SEM confirmed molten PE migrating along the nanofiber mat to repair delamination fronts, explaining the laminate’s bell-shaped, oscillation-free force response and demonstrating a practical, synergistic self-healing mechanism. Collectively, the results demonstrate a clear structure–property connection: PAN nanofibers capture crack growth, while PE provides temperature-triggered self-healing, and their synergy offers a practical pathway to lightweight GFRP structures with enhanced impact resilience and restoration of mechanical integrity. Full article

As remote and hybrid work models continue to grow, the design of workspaces and their surrounding environments has gained even more importance. This study explores the impact of window design on the restorative potential of Prefabricated Movable Buildings (PMBs) of smart/co-working located in small villages. Using Immersive Virtual Reality (IVR), seven window configurations, varying in size, frame ratio, and number of glass panes, were evaluated. Participants’ sense of presence, defined as the subjective feeling of ‘being there’ in the virtual environment, and perceived restoration, referring mainly to the psychological (attention and emotions) and physiological (stress) resources recovery, were assessed using, respectively, Igroup Presence Questionnaire (IPQ) and the Perceived Restorativeness Scale (PRS). The overall IPQ results suggest that the virtual environment in this study provides a “High” sense of presence, highlighting the validity of IVR to evaluate architectural designs. The PRS results found that larger, uninterrupted windows with a higher Window-to-Wall Ratio and lower Frame Ratio significantly enhance participants’ perceived restoration. Restoration effects were also higher when offices were located in small villages rather than in business districts. These results highlight the importance of incorporating large windows in smart/co-working spaces within culturally rich small villages to promote worker well-being and office sustainability. Full article

Background: Prophylactic polishing pastes (PPPs) are widely used to clean teeth and dental restorations; however, their effects on restorative materials are crucial for clinical outcomes. This study investigates the impact of PPPs on the susceptibility of CAD/CAM restorative materials to staining and the relationship between surface roughness and discoloration. Methods: Samples of tested materials (resin nanoceramic, hybrid ceramic, feldspathic ceramic, and lithium disilicate-reinforced glass ceramic) were treated with various PPPs (Cleanic, CleanJoy, Detartrine, Proxyt). Surface roughness and color parameters were recorded before and after the PPP application and following coffee immersion for 12 days. Initial measurements of surface roughness (Ra1) and color were taken. The specimens were divided into groups based on the PPP applied. After PPP application, secondary roughness (Ra2) and color values were measured. Changes in roughness (ΔRa), color (ΔE*ab, ΔE00), and whiteness index (ΔWID) were calculated post-application and after coffee immersion. Data normality was tested with the Shapiro–Wilks test. Two-way ANOVA evaluated the effects of material type and PPP on ΔE, ΔWID, and ΔRa. One-way ANOVA, Tukey HDS test, and Pearson correlation were used for further analysis, with significance set at p < 0.05. Results: The Vita Enamic–Detartrine group showed the highest ΔEab 1 and ΔE001 values, while Cerasmart–control showed the lowest. The Vita Enamic–Proxyt group had the lowest ΔWID1, and Vita Enamic–Cleanjoy exhibited the highest values of ΔEab 2, ΔE002, and ΔWID2. The E.MAX–control group had the lowest values for these metrics. No significant correlation was found between ΔRa and color changes (ΔE*ab 2, ΔE002, ΔWID2); however, a moderate positive correlation was found between values of ΔE1 and ΔE2. Conclusions: These findings indicate that PPPs significantly affect the discoloration and surface features of CAD/CAM materials, with both types of PPPs and materials. Full article

This study aimed to evaluate the influence of different fluoride-containing toothpastes on fluoride uptake, surface roughness, and microhardness of six ion-releasing restorative dental materials, including glass hybrids (EQUIA Forte HT with and without coating), glass ionomer cements (Fuji IX), resin-modified GICs (Fuji II LC), alkasites (Cention Forte), and ion-releasing composites (Luminos UN and Activa). Specimens were prepared and subjected to a four-day brushing protocol using six toothpastes with varying fluoride formulations (NaF, SnF2, SMFP) and concentrations. Fluoride uptake was assessed by measuring fluoride release using an ion-selective electrode, while surface roughness and microhardness were assessed before and after brushing. Results revealed significant variations in fluoride uptake, with Fuji IX and EQUIA Forte HT showing the highest release, particularly when brushed with NaF-based toothpastes (Duraphat 5000 and 2800). Surface roughness increased post-brushing, with the greatest changes observed in Activa, while microhardness decreased across most materials, except for coated EQUIA Forte HT, which exhibited improved compactness. Resin-based composites, such as Luminos UN and Activa, demonstrated lower fluoride uptake and minimal changes in microhardness compared to GICs. The findings underscore the importance of material composition and toothpaste formulation in influencing fluoride dynamics, surface properties, and mechanical performance of restorative materials. Full article

Objective: This study aims to evaluate the influence of pontic length and design on the fracture resistance of zirconia fixed dental prostheses (FDPs). By assessing different span lengths under controlled mechanical loading conditions, the research seeks to provide insights into optimizing the structural integrity of zirconia dental bridges. Materials and Methods: A total of 20 zirconia bridges were fabricated and tested in vitro. Ten bridges were designed to replace a single missing molar (tooth 46), with a pontic span of 11 mm, while the remaining ten were crafted for two missing teeth (35 and 36), featuring a longer pontic span of 17 mm. The zirconia frameworks were milled using the Wieland Zenotec^® Select Hybrid system and cemented onto metal abutments with Voco Meron Plus QM resin-reinforced glass ionomer cement. The specimens were subjected to occlusal loading using a ZwickRoell ProLine Z005 testing machine at a crosshead speed of 1 mm/min until fracture occurred. Results: The mechanical testing revealed a significant correlation between pontic length and fracture resistance. The mean fracture resistance for three-unit bridges (single pontic) was 3703 N, whereas four-unit bridges (double pontic) exhibited a significantly lower resistance of 1713 N. These findings indicate that increased span length reduces the fracture resistance of zirconia restorations due to higher stress accumulation and reduced rigidity. Conclusions: This study underscores the importance of pontic length and design in determining the fracture resistance of zirconia restorations. Shorter spans exhibit greater structural stability, reinforcing the need for careful treatment planning when designing multi-unit zirconia bridges. By optimizing bridge parameters, clinicians can improve clinical outcomes and extend the longevity of zirconia prostheses in restorative dentistry. Full article

Background: This study aims to compare the compressive strength and microhardness of four tooth-colored restorative materials: bulk fill glass hybrid (GH), resin-modified glass ionomer (RMGIC), conventional glass ionomer (CGIC), and resin-based composite (RBC). Methods: Stainless steel molds were used to prepare 20 specimens for each material. Half of the specimens were subjected to 10,000 thermal cycles; the materials were subjected to compressive strength and microhardness tests. Mean values were statistically compared using a one-way ANOVA Test and Bonferroni pairwise comparisons. Results: GH (147.03 ± 20.19 MPa) had lower compressive strength than RBC (264.82 ± 30.95 MPa) but showed no significant difference with CGIC (130.19 ± 30.38 MPa) and RMGIC (183.52 ± 18.45 MPa). RMGIC’s compressive strength also significantly fell short of RBC (p < 0.05), but it significantly increased after thermocycling (160.14 to 183.52 MPa). As for microhardness, no significant difference was found between the groups. Thermocycling significantly increased the microhardness of CGIC (from 24.27 to 31.8 ± 2.66). Conclusion: Resin-based materials outperformed the other materials. Glass hybrid restorative material performed as well as resin-modified glass ionomer regarding compressive strength; however, further studies are necessary before considering glass hybrids for use as a permanent restoration. Full article

In 2017, Europe implemented a ban on amalgam restorations for children aged <15 years and for pregnant/breastfeeding women, highlighting the need for alternative filling materials exhibiting less surface roughness and enhanced longevity. This in vitro study aimed to examine the surface roughness variations of five amalgam-replacement materials across three time points and using six finishing methods: (1) no finishing (control), (2) Arkansas burs, (3) diamond burs, (4) tungsten carbide burs, (5) SofLex discs in descending grit size, and (6) coarse SofLex discs combined with silicone polishing. We prepared 960 samples. Each material group, i.e., Cention Forte (CNF), DeltaFil (DLF), Ketac Universal (KTU), IonoStar Molar (ISM), and Equia Forte HT (EQF), comprised 60 samples (n = 10 per finishing method) created using standardized 3D-printed metal molds. Surface roughness (Sa) was measured immediately after finishing, after 30 days of storage in distilled water, and after thermocycling (5000 cycles) using a non-contact profilometer. The results indicate that conventional and hybrid glass-ionomer cements have smoother surfaces than high-viscosity GICs. The DLF and CNF groups exhibited stable outcomes. These findings underscore the importance of selecting appropriate finishing methods based on the restorative material to minimize surface roughness. Full article