The essential factor in determining the preservation of restoration is the marginal seal. Restoring cervical lesions with a resin composite has always been a challenge. Composite resins with various viscosities and different bonding systems are being researched to reduce the microleakage. Confocal laser scanning microscopy (CLSM) is the latest non-destructive technique for visualizing the microleakage. Objectives: To evaluate and compare the microleakage of Universal Flo composite resin (G-aenial) using etch and rinse adhesive system ER-2 steps (Adper Single Bond 2), self-etch adhesive system SE-1 step (G-Bond), and self-adhesive flowable composite resin (Constic) in Class V cavities using a confocal laser scanning microscope. Materials and Method: Class V cavities were prepared on 27 caries-free human extracted premolar teeth on the buccal and lingual surfaces with standardized dimensions of 2 mm height, width 4 mm, and a depth of 2 mm. After the cavity preparation, all teeth were randomly divided into three groups, namely Group-I: G-aenial Universal Flo with Single Bond 2 (n = 9 teeth); Group-II: G- aenial Universal Flo with G-Bond (n = 9 teeth), and Group-III: Constic (n = 9 teeth). The prepared and restored specimens were then subjected to thermocycling for 500 cycles in a water bath at 5 °C and 55 °C with a dwelling time of 30 s. The specimens were placed in 0.6% aqueous rhodamine dye for 48 h. Sectioning was carried out bucco-lingually and specimens were evaluated for microleakage under a confocal laser scanning microscope. Results: There was a significant difference (p = 0.009) in microleakage when comparing total etch and rinse, specifically between Adper Single Bond 2 ER-2 steps (fifth generation) and self-adhesive flowable composite resin, which is Constic. There was more microleakage in the self-etch bonding agent, particularly G-Bond, SE-1 step (seventh generation), when compared to ER-2 steps (fifth generation bonding agent); however, the results were not statistically significant (p = 0.468). The self-adhesive flowable composite resin showed more microleakage than SE-1 step and ER-2 steps. Conclusions: None of the adhesive systems tested were free from microleakage. However, less microleakage was observed in the total etch and rinse, especially Adper Single Bond 2 (ER-2 steps), than the self-etch adhesive system SE-1 step and self-adhesive flowable composite resin. Clinical significance: Constant research and technological advancements are taking place in dentin adhesives to improve the marginal seal. This has led to the evolution of total acid-etching dentin bonding agents termed as etch and rinse (ER)-2 steps (fifth generation dentin bonding agents) and self-etching (SE) 2 steps, and SE-1 step dentin bonding agents termed as the sixth and seventh generation bonding agents, respectively.

Objective: This study aimed to assess the effect of four different surface-coating agents on the microhardness, water sorption, and solubility of the highly viscous glass ionomer cement EQUIA Forte^® HT. Materials and methods: A total of 100 cylindrical EQUIA Forte^® HT samples were examined, with 50 tested for Vickers hardness and the other 50 for water sorption and solubility. For each test, the specimens were divided into five groups (10 specimens/group) according to coating method: Group 1—no coating (control), Group 2—EQUIA Forte^® Coat, Group 3—Single Bond™ Universal Adhesive, Group 4—ExciTE^®F adhesive, and Group 5—petroleum jelly. Data were analyzed using the paired t-test, one-way analysis of variance, and Tukey’s post hoc test for multiple comparisons. Statistical significance was set at p < 0.05. Results: The mean microhardness of the coated groups was significantly higher than that of the uncoated group. Moreover, a significant difference in the microhardness value was detected between the coated groups. Furthermore, EQUIA Forte^® Coat had the highest mean hardness value. The mean water sorption at 7 days showed that EQUIA Forte^® Coat had the lowest values. In terms of water solubility, a statistically significant difference was found between no coating and all groups except EQUIA Forte^®, between Single Bond Universal Adhesive and petroleum jelly, between petroleum jelly and EQUIA Forte Coat, and between EQUIA Forte^® Coat and ExciTE^®F. Conclusions: The study revealed that all coating agents significantly increased the microhardness of EQUIA Forte^® HT, with EQUIA Forte^® Coat showing the highest hardness and the lowest water sorption values.

Aim: This study aims to assess the impact of various reparative remineralizing agents, specifically topical fluoride (TF) and a combination of a carbon dioxide laser (CO₂ laser) with TF, as well as regenerative agents such as Curodont™ Repair and NR-5™, on two key factors—the micro-Vickers hardness (VH) of eroded enamel and the micro-shear bond strength (µSBS) of composite restoration. Materials and Methods: A total of 50 single-rooted premolars with intact enamel were sectioned mesiodistally into two halves, making a sample size of 100 specimens. All of the samples were then exposed to Coca-Cola^TM for 2 min each day over 1 month to induce erosion on the enamel surface. The specimens were then embedded in acrylic cold-cure resin facing a flat surface upward. The samples were then arbitrarily divided into five groups based on the remineralizing and regenerative agents used, as follows (n = 20): Group 1: No remineralizing agent, Group 2: Curodont™ Repair, Group 3: NR-5™, Group 4: TF, and Group 5: CO₂ laser + TF. The VH of the pretreated enamel surfaces was analyzed and µSBS testing and failure mode of composite restoration were performed using a universal testing machine (UTM) and stereomicroscope. ANOVA and Tukey’s post hoc were performed for data analysis. Results: In Group 3, the (NR-5™)-treated teeth exhibited the highest VH values and µSBS. In Group 1, the (No remineralizing agent)-treated specimens displayed the lowest VH and the lowest µSBS. An intergroup comparison analysis unveiled that Group 3, Group 4 (TF), and Group 5 (CO₂ laser + TF) presented comparable outcomes of microhardness and bond strength. The Group 2 (Curodont™ Repair) samples exhibited no significant difference in VH and µSBS, as compared to Group 1. Conclusions: The use of a combination of NR-5™ technology and a CO₂ laser in conjunction with TF has been shown to significantly augment the natural mineralization process. This enhancement results in increased microhardness and an improved bond strength in the treated enamel.

Assessment of the impact of different dentin bio-modifiers i.e., Bromelain, Riboflavin photosensitizer (RFP/Ultraviolet-A), and Chitosan nanoparticles (CHNPs) on the shear bond strength (SBS) and microleakage of composite bonded to acid etched carious affected dentin (CAD). Sixty-four human molars in which carious lesions extend till the middle third of the dentin were included. The infected dentin was removed and CAD was exposed. All specimens were categorized into four groups based on the application of dentin bio-modifier (n = 16) Group 1 (No dentin modifier), Group 2 (Bromelain), Group 3 (RFP/UVA), and Group 4 (CHNPs). Dental adhesive application and composite buildup were performed. A dye penetration test was used to assess marginal leakage. Resin CAD interface assessment was performed using SEM. For SBS and failure pattern analysis, a universal testing machine and stereomicroscope were used respectively. One-way ANOVA followed by Bonferroni's posthoc test was employed to analyze the differences among various groups (p≤0.05) RESULTS: The lowest microleakage (13.27 ± 0.10) and highest SBS (11.64 ± 0.16 MPa) were observed in Group 2 (Bromelain). However, the maximum values of marginal leakage (37.21 ± 0.21) and minimum SBS (7.34 ± 0.07 MPa) were detected in Group 1 samples. The length of resin tags in the Group 2 specimens (Bromelain) was found to be the highest (102.11 ± 5.12 μm)^. However, Group 1 (No modifier) exhibited the lowest resin tag length (50.45 ± 2.37 μm). Caries-affected dentin modified with Bromelain resulted in satisfactory SBS with minimal microleakage scores. Chitosan nanoparticles and RFP/Ultraviolet-A also presented better outcomes in terms of microleakage and SBS than the control.