Effect of casein phosphopeptide-amorphous calcium phosphate, Riva Star, and Moringa oleifera-based nano-silver fluoride on caries affected dentin remineralization bonded to composite resin.

OBJECTIVE: This study aims to assess the effects of the most recent remineralizing agents, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), CO2 laser irradiation + topical fluoride (CO2 laser + TF), and Nanosilver fluoride - M. oleifera (NSF-MOLE), on the shear bond strength (SBS) and bond failure between resin composite and remineralized caries affected dentin (CAD). MATERIALS AND METHODS: Fifty human molars with occlusal caries reaching approximately halfway through the dentin were immersed in a 4% thymol solution. The infected dentin was removed using an excavator and the CAD surface was exposed. The sample was allocated into five groups (n=10) based on the remineralizing agent applied. Group 1: no remineralizing agent, group 2: CPP-ACP, group 3: Riva Star, group 4: NSF:MOLE, and group 5: (CO2 laser + TF). The shear bond testing procedure was conducted utilizing a universal testing machine and a stereo-microscope was used to study the failure pattern. The researchers utilized a one-way analysis of variance. The Tukey post hoc test was conducted for multiple comparison tests. RESULTS: Group 4 (NSF-MOLE) (13.77±1.94 MPa) treated testers recognized the highest bond values of tooth color restoration to the CAD surface. Nonetheless, group 1 test samples with no mineralization unveiled the minimum outcome of bond integrity (9.12±1.14 MPa). Intergroup comparison exploration showed that group 2 (CPP-ACP), group 4 (NSF-MOLE) (13.77±1.94 MPa), and group 5 (CO2 laser + TF) established comparable values of SBS. Furthermore, group 3 (Riva Star) displayed better SBS than group 1 but lower than group 2, group 4, and group 5. CONCLUSIONS: Remineralization of CAD using modern regimes (CPP-ACP, NSF-MOLE, and CO2 laser + TF has the potential to be used to enhance the bond strength of CAD to composite restoration.

The impact of PEEK pretreatment using H2SO4, riboflavin, and aluminum trioxide on the extrusion bond strength to canal dentin luted with Polymethyl methacrylate and resin-based composite cement.

OBJECTIVE: To evaluate the effects of various surface pretreatment methods, including H2SO4, Riboflavin, and Al2O3, as well as different luting cement types, namely Methyl Methacrylate based Cement (MMBC) and composite-based cement (CBC), on the extrusion bond strength (EBS) of poly-ether-ether-ketone (PEEK) posts bonded to canal dentin. MATERIALS AND METHODS: This study involved 120 single-rooted human premolar teeth that underwent endodontic treatment. Following root canal preparation, PEEK posts were fabricated from PEEK blanks using a CAD-CAM system, resulting in a total of 120 posts. The posts were randomly assigned to one of four groups based on their post-surface conditioning: Group A H2SO4, Group B RF, Group C Al2O3, and Group D (NC), each consisting of 30 posts. Within each group, there were two subgroups based on the type of luting cement used for bonding. Subgroups A1, B1, C1, and D1 (n=15 each) utilized CBC, while Subgroups A2, B2, C2, and D2 (n=15 each) used MMBC.The bond strength between the PEEK posts and root dentin was assessed using a universal testing machine, and the failure modes were examined under a stereomicroscope. Statistical analysis, including one-way analysis of variance (ANOVA) and Tukey's Post Hoc test with a significance level of p=0.05, was performed to analyze the data and evaluate the effects of surface treatment and luting cement type on the bond strength. RESULTS: Group B2, which underwent RF conditioning followed by Super-Bond C&B cement application, exhibited the highest bond strength scores at the coronal section (9.57±0.67 MPa). On the other hand, Group D1, which had no conditioning (NC) and used Panavia® V5 cement, showed the lowest EBS at the apical third (2.39±0.72 MPa). The overall results indicate that the different conditioning regimens and luting cement types did not significantly influence the bond strength of PEEK posts to root dentin (p>0.05). CONCLUSIONS: Riboflavin activated by photodynamic therapy (PDT) and H2SO4 can be effective surface conditioners for PEEK posts. These treatments have shown potential for enhancing the bond strength between PEEK and resin cement. Additionally, the study revealed that MMA-based cement outperformed composite-based cement in terms of bond integrity with PEEK posts.

Effect of Translucency and Curing Mode of Four CAD/CAM Materials on Polymerization Efficiency of Light and Dual Cure Resin Cements.

PURPOSE/AIM: To determine the effect of translucency of four CAD/CAM materials and different curing modes on the degree of conversion of resin cements. MATERIALS AND METHODS: Disks were fabricated from IPS e.max CAD, Vita Suprinity, Vita Enamic, and DD Cube X². Translucency was measured using a spectrophotometer. The degree of conversion of two resin cements Variolink Esthetic DC and LC were measured using a Fourier transform infrared spectrometer. For Esthetic DC, the degree of conversion was determined in self-cure and dual cure modes. ANOVA, Tukey HSD test, and /Linear Regression R2 were used to statistically analyze the data. RESULTS: There was a significant difference in the translucency of the four materials (P ⟨ 0.0001). The mean translucency of Vita Suprinity was significantly higher, followed by Vita Enamic, DD Cube X², and IPS E.max CAD. Degree of conversion of resin cements cured under DD Cube X² had the highest values (25.22%), whereas those cured under Vita Suprinity showed the lowest values (17.86%). The self-cure mode had the lowest degree of conversion values (16.22%) and dual cure mode showed the highest values (26.12%). A negative linear relationship was found between degree of conversion and translucency of the CAD/CAM materials.

Evaluation of the marginal microleakage of CAD-CAM compared with conventional interim crowns luted with different types of cement: An in-vitro study.

BACKGROUND: Temporary stage in crowns and bridgework plays an important role in the success and failure of the final restorations. Lack of marginal seal of the temporary restorations can lead to further complications. Recently, digital dentistry has been improved in terms of marginal integrity. AIMS: The aim of this study was to evaluate and compare the marginal leakage between CAD/CAM and conventionally made Polymethyl methacrylate (PMMA) interim crowns cemented with different temporary luting cements. MATERIALS AND METHODS: Sixty resin dies of a maxillary right first premolar were prepared according to the protocol of the tooth preparation for all-ceramic crown. Interim crowns were then fabricated and assigned to two main groups according to the fabrication technique (CAD/CAM technique and conventional technique). Furthermore, the samples were sub-grouped (n = 10) according to the type of the luting cements: Zinc oxide eugenol (RelyX temp E), Zinc oxide non-eugenol (RelyX temp NE), and Zinc polycarboxylate cement (pentron). The specimens were then subjected to thermocycling at 5°C and 55°CC for 30 sec and transfer time of 15 seconds for 1500 cycles. After that, the specimens were immersed in a 2% methylene blue solution for 24 hours. The cemented specimens were sectioned buccolingually and the amount of marginal leakage was evaluated under digital microscope at magnification 50x. The scores of dye penetration were recorded and analyzed using one-way ANOVA at P < 0.05 for all tests. RESULTS: For the fabrication technique, CAD/CAM-made interim crowns had significantly better performance in terms of lower microleakage in comparison to conventionally built interim crowns (P < 0.001). Overall, Zinc Oxide non-eugenol also showed significantly least microleakage as a luting cement then Zinc Oxide Eugenol and the most microleakage was found with Zinc Polycarboxylate regardless of the fabrication method. CONCLUSION: Interim crowns fabricated by CAD-CAM system are better suited for temporization. Zinc-oxide non-eugenol cements showed the least amount of microleakage in both types of crown.