Search Results (79)

The study aimed to evaluate the effect of chlorhexidine (CHX), chlorin p6-mediated photodynamic therapy (PDT), magnesium oxide nanoparticles (MgONPs), and Clp6-functionalized MgONPs on smear layer removal and shear bond strength of a two-step etch-and-rinse adhesive to caries-affected dentin. Seventy-five human permanent molars with occlusal carious lesions and ICDAS scores of four and five were included. Twenty-five samples were used to prepare dentin discs 2 mm in thickness. The remaining samples, along with 25 discs, were arbitrarily allocated into five disinfectant groups, with n = 15 per group (10 teeth and 5 discs). Group I: Control, Group II: 2% CHX, Group III: Clp6-mediated PDT, Group IV: MgONPs, and Group V: Clp6-functionalized MgONPs. SL removal assessment, nanoparticle characterization, and EDX were performed using SEM. Fifty CAD were etched, followed by fifth-generation adhesive application and composite build-up. SBS and failure modes were evaluated with a universal testing machine and stereomicroscope, respectively. Group 4 (MgONPs) specimens displayed the maximum cleaning of SL (1.11 ± 0.13) and the highest SBS (10.32 ± 0.18 MPa). However, minimum SL removal (2.87 ± 0.94) and bond strength (7.42 ± 0.25 MPa) were exhibited by Group 1 (No disinfectant) samples. MgONPs possess the potential to be used as a cavity disinfectant, as they efficiently remove SL from CAD and augment the bond integrity outcomes. Full article

Non-carious cervical lesions (NCCLs) present restorative challenges due to substrate sclerosis and marginal stress concentration, making the adhesive strategy a key determinant of long-term performance. This systematic review and frequentist random-effects network meta-analysis, conducted in accordance with PRISMA 2020 and the PRISMA-NMA extension and prospectively registered in PROSPERO, compared restorative strategies defined by etching approach, adhesive category, and restorative material, with marginal adaptation and retention loss as the primary outcomes. PubMed, Web of Science, Cochrane Library, Embase, and Scopus were searched without restrictions (25 January 2026), supplemented by alternative retrieval methods. Randomized clinical trials in permanent teeth evaluating at least two etching-based strategies (etch-and-rinse, self-etch, selective-etch, and/or resin-modified glass ionomer cement (RMGI)) were included. Risk of bias was assessed using RoB 2 and certainty of evidence with CINeMA. Seventy-four trials were eligible. Connected networks were established for marginal adaptation (57 studies; 28 interventions; 6798 patients; 1772 events) and retention loss (61 studies; 33 interventions; 7338 patients; 584 events). Selective-etch with a universal adhesive and nanocomposite reduced marginal adaptation failure compared with RMGI, whereas certain self-etch and non-universal combinations increased risk. For retention loss, selective-etch and etch-and-rinse protocols combined with universal adhesives and nanocomposites showed lower failure rates, while some self-etch or non-universal adhesive strategies performed less favorably. Overall confidence was predominantly high, with downgrading mainly due to imprecision and heterogeneity. Strategies incorporating selective enamel etching or etch-and-rinse approaches combined with universal adhesives and nanocomposites demonstrated the most consistent clinical advantages. Full article

Background/Objectives: The classification of adhesive systems has historically relied on the type of etching agent and the sequence of application steps, distinguishing etch-and-rinse and self-etch categories. However, these models do not encompass the versatility introduced by universal adhesives or other emerging polymeric materials. This review aimed to integrate etching technique as a defining parameter within adhesive classification, linking material composition, bonding strategy, and clinical execution into a coherent functional framework. Methods: A structured narrative review of experimental, translational, and clinical studies published between 2010 and 2025 was conducted using PubMed and Scopus. Literature addressing adhesive categories, etching strategies, etching techniques, and smear layer characteristics was critically synthesized to identify functional relationships relevant to bonding performance and clinical decision-making. Results: The proposed taxonomy classifies materials as conventional, universal, touch-cure primers, self-adhesive/universal, and glass ionomer cements. Bonding strategies are organized as etch-and-rinse, self-etch, pre-etched, and unassisted, while etching techniques are defined as selective or nonselective families encompassing five clinically defined techniques. Incorporating etching technique clarifies the role of smear layer density, the acidity of adhesive materials, and functional monomer reactivity in demineralization and bonding. This structure enhances the understanding and teaching of adhesive concepts and supports evidence-based clinical selection of materials and techniques. Conclusions: Integrating etching technique into adhesive classification provides a functional and dynamic framework that unifies material, strategy, and technique. This taxonomy facilitates clinical decision-making and can evolve with future adhesive formulations. Further independent, long-term studies are warranted to validate the proposed combinations of materials and etching procedures. Full article

This study aims to evaluate the effects of different surface treatments and adhesive systems on the shear bond strength (SBS) of additively manufactured (AM) and subtractively manufactured (SM) restorative materials. A total 675 rectangular specimens of three AM (Saremco Crowntec/SC, VarseoSmile CrownPlus/VC, and VarseoSmile TriniQ/VT) and two SM (Vita Enamic/VE and Cerasmart/CS) restorative materials were fabricated. Each material was randomly divided into three groups regarding surface treatments: control/C, sandblasting/S, and etching/E. Following surface treatments, each AM and SM restorative material was then divided into three subgroups (15 specimens/subgroup) on the basis of adhesive systems (etch-and-rinse, self-etch, and universal). All specimens were thermocycled at 10,000 cycles, 5–55 °C, 30 s dwell time, and tested under SBS until failure, and failure types were examined under a stereomicroscope. Representative specimens were examined by SEM to evaluate fracture morphology. Statistical analysis was set at p < 0.05. There were significant differences in bond strength according to the material, surface treatment, adhesives, and their interactions (p < 0.05). The highest SBS value was obtained with SC × sandblasting × etch-and-rinse (16.45 ± 0.93 MPa), while the lowest value was found in the CS × control × universal interaction (4.68 ± 1.1 MPa). Outcomes varied according to the materials, surface treatment, and adhesive strategy. Clinically, these findings indicate that SM materials may require various surface treatment to achieve reliable adhesion, whereas AM materials provide more similar bond strength performance with no surface treatment. Full article

Objectives: Investigating and comparing the micro-tensile bond strength (µTBS) of etch-and-rinse (ER) or self-etch (SE) adhesives on sound (s) and eroded (e) human (H) and bovine (B) dentin. Methods: Twenty-four human and bovine teeth were divided into eight groups (n = 6) and coronally ground down, exposing their dentin. Two groups of human (HeER + HeSE) and bovine teeth (BeER + BeSE) were subjected to erosive challenges (citric acid (pH 2.7), 10 × 2 min per day for five days, and stored in artificial saliva). Groups HsER + HeER and BsER + BeER were treated with an etch-and-rinse adhesive (OptiBond FL), and groups HsSE + HeSE and BsSE + BeSE were treated with a self-etch adhesive (OptiBond All-in-One), followed by buildups with a composite restorative material. After seven days of storage in tap water, µTBS was determined and failure type analysis was performed. Data were evaluated using two-way ANOVA and Tukey’s post hoc tests at a level of significance of α = 0.05. Results: Using etch-and-rinse adhesive, sound human dentin (HsER) showed the significantly highest µTBS (p < 0.05) compared to eroded human (HeER) and sound and eroded bovine dentin (BsER + BeER). For sound human and bovine specimens (HsSE + BsSE), there was no significant difference (p ≥ 0.05) in µTBS when self-etch adhesive was applied, as well as in the eroded specimens (HeSE + BeSE). Conclusions: Within the limitations of this study, it can be concluded that for the etch-and-rinse approach, it is not recommended to substitute human dentin with bovine dentin. When using the specific self-etch adhesive used in the present study, bovine dentin can be used to substitute human dentin, as they showed comparable µTBS. Full article

The present study aimed to evaluate the effect of air-abrasion as a dentin pre-treatment on the bond strength of contemporary adhesive systems. The bonding approaches included etch-and-rinse (ER), self-etch (SE) and universal (UN) adhesive systems, with the latter applied in both ER and SE modes. Twenty-eight third molars were used, each sectioned in four parts. All specimens were embedded in acrylic resin, ground with silicon carbide papers, and divided into eight experimental groups (n = 14) based on the combination of surface pre-treatment (air-abrasion or none) and adhesive approach. Subsequently, a resin cylinder was bonded to each surface following the respective treatment. Shear bond strength (SBS) was evaluated at a cross-head speed of 0.7 mm/min using a shear-testing machine (OM100 Odeme, Luzerna, Brazil). The data were analyzed with one-way ANOVA and Tukey’s post hoc test. No statistically significant increase in SBS after air-abrasion of dentin was found for any of the experimental groups (p > 0.05). Among the adhesive strategies, the ER system presented higher SBS values (32.81 ± 9.04 MPa) than the UN adhesive applied in SE mode (21.68 ± 5.85 MPa) (p < 0.05). Mixed failures were the most common failure type across all groups. In particular, 20.5% of the specimens exhibited adhesive failure, 14.3% cohesive failure within resin composite, 12.5% cohesive failure within dentin and 52.7% specimens demonstrated mixed failure types. Dentin pre-treatment with air-abrasion using 29 μm Al₂O₃ did not significantly increase the SBS of the three tested contemporary adhesive systems; however, the choice of adhesive strategies influenced the SBS outcomes. Full article

Background/Objectives: Adhesion to caries-affected dentin remains challenging due to its altered structure and composition. Remineralizing agents have been proposed to strengthen this substrate and improve bonding. This study evaluated the effect of three remineralization treatments, CPP-ACP, self-assembling peptide P11-4, and silver diamine fluoride (SDF), on the microtensile bond strength (μTBS) of universal adhesive systems applied to caries-affected dentin, using both etch-and-rinse and self-etch strategies. Methods: Seventy human molars were sectioned and artificially demineralized to simulate caries-affected dentin. Samples were divided into ten groups: four untreated and six treated with CPP-ACP (MI Paste™), P11-4 (Curodont™ Protect), or SDF (Riva Star™). Universal adhesives were applied via etch-and-rinse or self-etch mode, followed by composite restoration. Microtensile bond strength was measured using a universal testing machine, and results were statistically analyzed with ANOVA and t-tests (p < 0.05). Results: Untreated caries-affected dentin showed significantly lower μTBS than sound dentin (C3: 18.3 ± 5.4 MPa vs. C1: 41.3 ± 2.7 MPa). Remineralization agents improved μTBS considerably. CPP-ACP achieved the highest recovery (S1: 31.8 ± 2.6 MPa; S2: 29.2 ± 4.6 MPa), nearing sound dentin levels. P11-4 yielded moderate gains (S3: 24.4 ± 6.5 MPa; S4: 24.1 ± 4.7 MPa), while SDF provided the lowest, yet significant, improvements (S5: 23.7 ± 7.5 MPa; S6: 21.3 ± 5.3 MPa). Etch-and-rinse generally produced higher μTBS than self-etch, but differences were not statistically significant (p > 0.05). Conclusions: Pre-treatment of caries-affected dentin with CPP-ACP, P11-4, or SDF enhances universal adhesive bond strength, with CPP-ACP showing the most pronounced effect. Remineralization protocols represent a valuable adjunct in restorative procedures involving compromised dentin. 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

Background: In adhesive dentistry, debonding-on-demand is attractive for situations where no permanent attachment is required. Due to its destructive nature, ultraviolet (UV) light may be of interest for attenuating bond forces. The aim of this study was to investigate the impact of UV light on the shear bond strength (SBS) of etch-and-rinse (n = 4) and universal adhesives (n = 3). Methods: Glass-ceramic samples were bonded to bovine enamel surfaces (n = 10/adhesive) and subjected to shear bond testing before and after exposure to UV light (320–390 nm, 126 Jcm⁻²). Data was statistically analyzed by Mann–Whitney U test. Results: Initial photopolymerized etch-and-rinse adhesives showed superior SBS compared to universal adhesives. Highest values were recorded for iBOND^® Total etch (15.48 MPa) and Syntac classic© (17.60 MPa). Lowest SBS was obtained for Ecosite Bond^® (2.63 MPa). Additional UV exposure caused a significant decrease in SBS among iBOND Total etch (5.24 MPa, p = 0.009) and Solobond M© (3.65 MPa, p = 0.005), while for Syntac classic©, an increase (24.12 MPa, p = 0.047) was recorded. Among all other tested adhesives, no significant changes were observed. Conclusions: UV radiation impacted SBS of etch-and-rinse adhesives only (decrease: iBOND Total Etch, Solobond M; enhancement: Syntac classic©). Further research should focus on introducing sufficient light-triggered debonding mechanisms. Full article

Background/Objectives: It is unclear whether enamel margins should be beveled in direct resin-based restorations. This study evaluated the influence of enamel beveling on the marginal quality of mesio-occluso-distal (mod) cavity boxes. Methods: Seventy-five caries-free human molars were divided into three groups. Mod-cavities with the entire margin in the enamel were prepared ± proximal bevel (n = 25). Twenty-five beveled mod-cavities served as control. Each group was restored with five material combinations: micro hybrid composite with etch-and-rinse (ER) or self-etch (SE) adhesive, compomer with ER or SE, and low-shrinkage composite with ER. A complex filling technique was used in the control. After artificial aging (1000 thermal cycles, 5/55 °C), the percentage of continuous margins (PCM) of the proximal boxes was analyzed by scanning electron microscopy using epoxy replicas (×300), and the marginal seal was assessed by light microscopy after dye penetration (×64). Statistical analysis was performed using Kruskal–Wallis and Mann–Whitney U tests (p < 0.05). Results: No significant differences in PCM were found between the restorative systems (p = 0.075). The composite with low shrinkage showed the highest mean PCM of all groups (78.1%). Significant differences in marginal seal were observed between the restoratives after bevel preparation (p < 0.05). Beveling significantly improved the PCM only for the hybrid composite (p < 0.05), whereby the effect on marginal seal was less pronounced. Conclusions: Clinicians should be aware that beveling mod-cavities does not necessarily improve the marginal quality of direct resin-based restorations bonded with well-established adhesives and may be more beneficial for traditional hybrid composites. Full article

This study evaluated the effects of mechanical agitation of Aloe vera Barbadensis Miller solution at different concentrations using passive ultrasonic irrigation (PUI), XP Endo Finisher (XPF), XP Clean (XPC), and Easy Clean (ECL), compared to conventional endodontic irrigation (CIE), on bond strength and adhesive failure patterns in the cervical, middle, and apical thirds of the root canal. Aloe vera solutions at 1%, 3%, and 5% were tested to reverse collagen fiber collapse induced by hypochlorous acid, a free radical released by 2.5% sodium hypochlorite, which impairs dentin hybridization and the light curing of resin cement. Fiberglass posts were cemented using an etch-and-rinse adhesive system (Ambar; FGM) and conventional dual resin cement (Allcem Core) in root dentin across all thirds. Human teeth underwent chemical–mechanical preparation, and the Aloe vera solution was agitated using the CIE, PUI, XPF, XPC, or ECL protocols. Slices from each root third were evaluated under a stereomicroscope at 10× magnification and subjected to the push-out test. Cytotoxicity was assessed by applying various Aloe vera concentrations to stem cells from the apical papilla (SCAPs) for 24 h, followed by analysis of cell metabolism (Alamar Blue), viability (Live/Dead), and proliferation (F-actin). Aloe vera demonstrated significant biological activity and enhanced bond strength, particularly at 3% and 5%, irrespective of the agitation method or root third. Thus, it can be concluded that using Aloe vera solution is an alternative for pre-treatment before the cementation of fiberglass posts with conventional dual-cure resin cement in endodontically treated dentin. Full article

Novel dentin bonding pretreatment using copper sulfate (CuSO₄) and dipotassium hydrogen phosphate (K₂HPO₄) may create a more hydrophobic environment for dentin bonding. Thus, this study aims to investigate the impact of a CuSO₄ + K₂HPO₄ pretreatment on dentin μTBS when bonded with a universal adhesive to conventional and CAD/CAM resin composites. Eighty recently extracted human molars (n = 80) were chosen and placed in transparent acrylic blocks to expose the crowns entirely. Nano-filled resin composite and CAD/CAM resin blocks were selected. Based on the dentin pretreatment, type of resin composite, and adhesion strategy, the teeth were randomly allocated into eight equal groups (n = 10). The microtensile bond strength (μTBS) and fracture mode were determined. A three-way analysis of variance (ANOVA) was used to analyze the μTBS data, followed by Tukey’s post hoc test. The μTBS values were not significantly affected by either the resin composite type (p > 0.05) or the adhesive strategy (p > 0.05) according to the three-way ANOVA results. Conversely, significant differences were detected between no dentin pretreatment (24.20 ± 4.54 MPa) and CuSO₄ + K₂HPO₄ pretreatment (33.66 ± 5.22 MPa) using an etch-and-rinse adhesive strategy for nano-filled composites (p < 0.001). Additionally, significant differences were detected between no dentin pretreatment (24.71 ± 4.33 MPa) and CuSO₄ + K₂HPO₄ pretreatment (32.49 ± 4.92 MPa) using an etch-and-rinse adhesive strategy for CAD/CAM resin blocks (p < 0.001). Moreover, significant differences were detected between no dentin pretreatment (21.20 ± 3.40 MPa) and CuSO₄ + K₂HPO₄ pretreatment (30.31 ± 3.87 MPa) using a self-etching adhesive strategy for nano-filled composites (p < 0.001). Also, significant differences were detected between no dentin pretreatment (23.89 ± 3.89 MPa) and CuSO₄ + K₂HPO₄ pretreatment (31.22 ± 4.71 MPa) using a self-etching adhesive strategy for CAD/CAM resin blocks (p < 0.001). In conclusion, dentin μTBS was enhanced by a copper-based treatment when used with nano-filled and CAD/CAM resin blocks. Full article

This study aimed to evaluate the physicochemical and mechanical properties of a modified adhesive system containing resveratrol by assessing its microtensile bond strength (µTBS), degree of conversion (DC), mini-flexural strength (MFS), and antibacterial activity. The modified etch-and-rinse adhesive system was prepared by resveratrol (RES) incorporation in different concentrations: adhesive with 0.5% RES (RES0.5), adhesive with 1% RES (RES1), adhesive with 2% RES (RES2), and adhesive with no RES incorporation (RES0—control group). The µTBS test was conducted on 40 human molars with dentin exposure, which were etched, bonded with the adhesives (n = 10), and restored with resin composite. Fourier Transform Infrared Spectroscopy (FTIR) measured the DC for the MFS; ten adhesive sticks were made for each group. Antibacterial activity was assessed using colony-forming unit (CFU) counts. For µTBS, no difference between the groups was found (mean ± SD): RES0.5—42.93 ± 15.49^A; RES1—42.61 ± 13.97^A and RES2—39.43 ± 9.14^A; RES0—41.01 ± 2.64^A. The DC (% ± SD) of the experimental groups was similar: RES0.5—81.02 ± 1.95^A; RES1—76.02 ± 9.00^A; RES2—58.86 ± 15.94^A; RES0—77.75 ± 3.22^A. For MFS (mean ± SD): RES0.5—33.14 ± 13.83^A; RES1—31.1 ± 12.21^A; RES2—19.72 ± 5.43^B; RES0—29.72 ± 11.95^A. For CFU (mean ± SD): RES0.5—0.67 × 10⁷ ± 0.37^B; RES1—0.68 × 10⁷ ± 0.34^B; RES2—0.60 × 10⁷ ± 0.02^C; RES0—0.75 × 10⁷ ± 0.03^A. The incorporation of resveratrol into the adhesive system at low concentrations (0.5 and 1%) does not alter the bond strength of the adhesive interface, the degree of conversion, or the flexural strength. Additionally, both concentrations exhibited antibacterial properties by reducing the colony-forming units of S. mutans. Full article

This systematic review and network meta-analysis aimed to evaluate the bond strength of artificial caries-affected dentin (ACAD) of permanent human teeth with and without biomimetic remineralization (BR), assessed based on in vitro studies. Following PRISMA guidelines, we conducted a systematic search until June 2023, identifying 82 eligible articles for full-text analysis. We assessed the study characteristics, methodological quality, and summary results. Bond strength was examined immediately and after artificial aging using three bond strength tests. We performed meta-regressions (using OpenBUGS software) to explore the relationship between the independent variable’s adhesive application technique (Etch-and-Rinse or Self-Etch) and ACAD protocol (chemical or biological) and the dependent variable of bond strength. Additionally, we conducted random-effect NMAs (using CINEMA software) to compare the effect of multiple interventions per application technique and ACAD protocol simultaneously. Among the included studies that compared various BR strategies, most studies (19 out of 22) presented a medium risk of bias. In some comparisons, the meta-regression results revealed a significant association between bond strength at 24 h and both the adhesive application technique and the ACAD protocol. Our findings indicate the potential of BR to enhance bond strength in human ACAD in in vitro settings. Full article

(1) The aim of this in vitro study was to investigate the handling of proximal-cervical undermined enamel margins on the adhesive performance of differently fabricated and differently cemented ceramic inlays and partial crowns (2) Methods: 192 extracted third molars received MOD (n = 96) and partial crown (n = 96) preparations. A mesial 2 × 2 × 4 mm cervical groove was created in dentin to simulate a deeper (dentin) caries excavation. This dentin groove was either left (G/groove), filled with composite (F/filling), or completely removed (D/dentin). Distal proximal boxes did not receive a groove and served as controls within the same tooth. Labside (e.max Press) restorations additionally went through a temporary phase. Labside and chairside (e.max CAD) inlays and partial crowns were then adhesively luted with Syntac/Variolink Esthetic (SV) or Adhese Universal/Variolink Esthetic (AV). Initially, and again after thermomechanical loading (TML: 1 million cycles at 50 N, 25,000 thermocycles at 5 °C/55 °C), specimens were molded and the resulting 24 groups of epoxy replicas (n = 8) were gold-sputtered and examined for marginal gaps using scanning electron microscopy (200× magnification). Light microscopy (10× magnification) was used to measure proximal cervical crack propagation in adjacent enamel. (3) Results: Regardless of the adhesive system, D groups generally showed significantly lower marginal quality (79–88%; p < 0.05), with the universal adhesive performing better than the multi-step adhesive system (p < 0.05). Subgroups G and F were similar in marginal quality (94–98%; p > 0.05) and not worse than the controls (p > 0.05) regardless of the adhesive system, but showed less cracking in F than in G (p < 0.05). In general, fewer cracks were observed in chairside CAD/CAM restorations than in laboratory-fabricated restorations (p < 0.05). Partial crowns showed better marginal quality (96–98%) and less cracking than inlays (p < 0.05). (4) Conclusions: If the dentin level is lower than the enamel level in ceramic preparations after caries excavation in the proximal box, the resulting undermined enamel should not be removed. In terms of enamel integrity, partial crowns outperformed inlays. Full article