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

Objectives: This study was conducted to investigate marginal adaptation, compressive strength, water sorption, solubility, fluoride and calcium release of a claimed bioactive restorative material (ACTIVA BioACTIVE Restorative) compared to glass ionomer (Fuji IX) and resin composite (SphereTEC). Materials and methods: ACTIVA was evaluated relative to Fuji IX and SphereTEC one. Marginal gap width was detected via scanning electron microscope before and after thermo-cycling. Compressive strength was tested using universal testing machine. For measuring water sorption and solubility, specimens were immersed in distilled water, subjected to drying cycles and weighed. Fluoride ion release was measured using ion-selective electrode while released calcium ions were detected using Atomic Absorption Spectrophotometer after 1, 14 and 28 days. Data analysis was performed using ANOVA, paired t-test and independent sample t-test. Results: Marginal gap was reduced in both ACTIVA and Fuji IX after thermocycling while it increased in SphereTEC one. After thermo-cycling, the marginal gap was larger in dentin compared to enamel. SphereTEC one showed the highest compressive strength mean value. Fuji IX represented the highest water sorption values, followed by ACTIVA which also exhibited the highest solubility. Fuji IX showed higher fluoride release than ACTIVA whose calcium release did not reach 1ppm. Conclusion: ACTIVA restoration can provide a potential marginal seal. Compressive strength was limited compared to resin composite. ACTIVA’s water sorption and solubility are within the acceptable range. However, its fluoride and calcium release was limited.

Background: 3D-printed resin composite and hybrid ceramic materials are widely used in prosthetic dentistry for their esthetic, mechanical advantages, and digital compatibility, though their surface properties may be affected by drinking habits. This study aimed to evaluate the influence of a carbonated nutritional beverage multivitamin drink (Oronamin C) on the surface microhardness, roughness, solubility, and color changes in a recently introduced 3D-printed resin composite (Permanent Crown Resin), hybrid ceramic material (Vita Enamic) and a nanohybrid resin composite (Luna). Methods: A total of 120 disk-shaped specimens were distributed according to the type of material into three groups (n = 40). These were divided into four subgroups of specimens for each test (n = 10). The specimens were examined before and after immersion in Oronamin C solution for 12 days. Results: The results showed that there was no significant change in surface microhardness and surface roughness in both 3D-printed resin composite and hybrid ceramic after immersion, while microhardness decreased significantly in the nanohybrid resin composite with an increase in surface roughness. Solubility increased significantly in the nanohybrid and 3D-printed resin composites, but not in the hybrid ceramic. All materials presented clinically acceptable color changes, with mean values lower for both nanohybrid and hybrid ceramic. Conclusions: This study concluded that the hybrid ceramic and 3D-printed resin composite exhibited good stability after Oronamin C beverage exposure, whereas the nanohybrid resin composite exhibited the most impairment among all materials. All materials demonstrated clinically acceptable color changes.

Background: To evaluate the impact of incorporating chitosan/hydroxyapatite composite nanoparticles (CT/HAP NPs) into a universal adhesive on its bonding effectiveness to caries-affected dentin (CAD) and its in vitro bioactivity. Methods: CT/HAP NPs (50:50 by weight) were synthesized via a one-step co-precipitation method. All-Bond universal adhesive was modified with either 0.5 wt% or 1 wt% CT/HAP NPs, yielding three groups: unmodified control, 0.5 wt%, and 1 wt% CT/HAP. Forty-eight molar teeth (4 teeth per group) were used to prepare 240 bonded beams using either etch-and-rinse (ER) or selective-etch (SE) mode ( n = 20 bonded beams per group). Micro-tensile bond strength (µTBS) test was conducted using a universal testing machine after 24 h and 6 months of storage in simulated body fluid (SBF). Fifteen adhesive discs (5 mm x 1 mm) ( n = 5) were examined using an environmental scanning electron microscope combined with an energy-dispersive X-ray spectroscopy ( ESEM/EDX ) following storage in SBF for 1 day and 28 days to assess bioactivity and Ca/P ratio. Wettability, pH, and degree of conversion (DC) were assessed using a digital light microscope, a pH meter, and Fourier transform infrared (FTIR) spectroscopy, respectively. µTBS and wettability data were investigated utilizing multilevel ANOVA, while pH and DC were evaluated utilizing one-way ANOVA; Tukey’s post hoc test was applied for pairwise multiple comparisons. The significance level was set at ( p < 0.05). Results: The 1 wt% CT/HAP group exhibited significantly higher µTBS at 24 h (ER: 37.50 ± 6.90 MPa; SE: 32.52 ± 6.61 MPa) and at 6 months (ER: 41.81 ± 7.64 MPa; SE: 42.10 ± 7.23 MPa) than the 0.5 wt% CT/HAP and control groups. Adhesives containing CT/HAP NPs showed improved surface mineral deposition and higher Ca/P ratios compared to control. Wettability, pH, and degree of conversion revealed no significant changes. Conclusions: Incorporating chitosan/hydroxyapatite composite nanoparticles into an ultra-mild universal adhesive enhanced its bonding efficacy to caries-affected dentin as well as its bioactive potential, without jeopardizing the physical and chemical properties of the adhesive.

Background: Using infection control barriers (ICBs) on light curing units (LCUs) became mandatory to achieve proper infection control measures without jeopardizing the integrity of the restorations, especially at deeper layers. This study explored the effect of two ICBs on the irradiance of the LCU, as well as the degree of conversion (DC) and flexural strength (FS) of two types of bulk-fill composites. Water vapor permeability (WVP) of both barriers was also assessed to evaluate the capability of such barriers to prevent transmission of blood and saliva droplets and aerosols. Methods: Two bulk-fill composites (X-tra fil and Tetric N- ceram) and two ICBs (Pinnacle Cure sleeve and Sanita wrapping film) were used in this study. Light irradiance was recorded per experimental condition using spectroradiometer. For DC and FS, specimens of 4 mm thickness were prepared. Each specimen was composed of two separable upper and lower layers of thickness 2 mm. DC and FS were measured using Infra-red spectroscopy and three-point loading test respectively. WVP was investigated using the cup method. Means and standard deviations were calculated, and the data were statistically analyzed using factorial analysis of variance test (α = 0.05). Results: Light irradiance showed highest values using no ICBs and lowest values using Pinnacle curing sleeve. Both bulk-fill composites showed higher DC mean values without ICBs and when using Sanita wrapping film for both upper and lower layers of the specimens compared to Pinnacle curing sleeve. The upper layers of composite specimens showed higher DC compared to lower layers for all experimental conditions. Both ICBs had no adverse effect on FS of both composites’ upper layers. Pinnacle sleeve significantly reduced FS of both composites’ lower layers. X-tra fil showed higher DC and FS compared to Tetric N-Ceram for all experimental conditions. Regarding WVP; the wrapping film showed higher WVP compared to the curing sleeve. Conclusions: Sanita wrapping film can be used as a successful ICB, without jeopardizing the concept of bulk-fill composites. Pinnacle cure sleeve can be considered an effective ICB, however its influence on properties and serviceability of bulk-fill composites remains questionable.