Antibacterial Dental Adhesive Containing Cetylpyridinium Chloride Montmorillonite.

Oral bacteria cause tooth caries and periodontal disease. Much research is being conducted to prevent both major oral diseases by rendering dental materials' antimicrobial potential. However, such antimicrobial materials are regarded as 'combination' products and face high hurdles for regulatory approval. We loaded inorganic montmorillonite with the antimicrobial agent cetylpyridinium chloride, referred to below as 'CPC-Mont'. CPC-Mont particles in a 1, 3 and 5 wt% concentration were added to the considered gold-standard self-etch adhesive Clearfil SE Bond 2 ('CSE2'; Kuraray Noritake) to render its antibacterial potential (CSE2 without CPC-Mont served as control). Besides measuring (immediate) bonding effectiveness and (aged) bond durability to dentin, the antibacterial activity against S. mutans and the polymerization-conversion rate was assessed. Immediate and aged bond strength was not affected by 1 and 3 wt% CPC-Mont addition, while 5 wt% CPC-Mont significantly lowered bond strength and bond durability. The higher the concentration of the antimicrobial material added, the stronger the antimicrobial activity. Polymerization conversion was not affected by the CPC-Mont addition in any of the three concentrations. Hence, adding 3 wt% CPC-Mont to the two-step self-etch adhesive rendered additional antimicrobial potential on top of its primary bonding function.

Different surface treatments and adhesive monomers for zirconia-resin bonds: A systematic review and network meta-analysis.

This review examined the efficacy of surface treatments and adhesive monomers for enhancing zirconia-resin bond strength. A comprehensive literature search in PubMed, Embase, Web of Science, Scopus, and the Cochrane Library yielded relevant in vitro studies. Employing pairwise and Bayesian network meta-analyses, 77 articles meeting inclusion criteria were analyzed. Gas plasma was found to be ineffective, while treatments including air abrasion, silica coating, laser, selective infiltration etching, hot etching showed varied effectiveness. Air abrasion with finer particles (25-53 µm) showed higher immediate bond strength than larger particles (110-150 µm), with no significant difference post-aging. The Rocatec silica coating system outperformed the CoJet system in both immediate and long-term bond strength. Adhesives containing 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) were superior to other acidic monomers. The application of 2-hydroxyethyl methacrylate and silane did not improve bonding performance. Notably, 91.2 % of bonds weakened after aging, but this effect was less pronounced with air abrasion or silica coating. The findings highlight the effectiveness of air abrasion, silica coating, selective infiltration etching, hot etching, and laser treatment in improving bond strength, with 10-MDP in bonding agents enhancing zirconia bonding efficacy.

Does an incomplete ferrule affect the fracture of endodontically treated teeth? A systematic review of in vitro studies.

OBJECTIVE: The purpose of this systematic review was to assess the impact of the incomplete ferrule on the fracture of endodontically treated teeth (ETT). DATA: The keywords such as "incomplete ferrule," "ferrule," "ferrule effect," "residual dentin," "remaining dentin," or "remaining coronal dentin" were used for searching, and only in vitro studies investigating the incomplete ferrule effect on natural teeth were included. SOURCES: PubMed, Medline, Embase, Cochrane Library, and Science Direct databases, and manual-searching. STUDY SELECTION: The search strategy yielded 1633 hits, and a total of 19 in vitro studies closely related to the effect of incomplete ferrule on ETT were included. CONCLUSION: The presence of an incomplete ferrule may significantly increase the fracture resistance of restored ETT, compared with restored ETT without ferrule. The number of residual axial walls of the incomplete ferrule may have an impact on the fracture resistance and fracture mode. The location of residual axial walls of the incomplete ferrule may affect the fracture resistance but not the fracture mode. CLINICAL IMPLICATIONS: Limited data suggest that the presence of incomplete ferrule has a positive effect on the fracture resistance of restored ETT. An incomplete ferrule can be an alternative for restoring ETT when a complete ferrule is not present. Nevertheless, further high-quality studies are still needed to offer more robust evidence and to take potential confounding factors into account.

High-Performance Bioinspired Microspheres for Boosting Dental Adhesion.

Dental adhesives are widely used in daily practice for minimally invasive restorative dentistry but suffer from bond degradation and biofilm attack. Bio-inspired by marine mussels having excellent surface-adhesion capability and high chemical affinity of polydopamine (PDA) to metal ions, herein, experimental zinc (Zn)-containing polydopamine-based adhesive formulation, further being referred to as "Zn-PDA@SiO2"-incorporated adhesive is proposed as a novel dental adhesive. Different Zn contents (5 and 10 mm) of Zn-PDA@SiO2 are prepared. Considering the synergistic effect of Zn and PDA, Zn-PDA@SiO2 not only presents excellent antibacterial potential and notably inhibits enzymatic activity (soluble and matrix-bound proteases), but also exhibits superior biocompatibility and biosafety in vitro/vivo. The long-term bond stability is substantially improved by adding 5 wt% 5 mm Zn-PDA@SiO2 to the primer. The aged bond strength of the experimentally formulated dental adhesives applied in self-etch (SE) bonding mode is 1.9 times higher than that of the SE gold-standard adhesive. Molecular dynamics calculations indicate the stable formation of covalent bonds, Zn-assisted coordinative bonds, and hydrogen bonds between PDA and collagen. Overall, this bioinspired dental adhesive provides an avenue technology for innovative biomedical applications and has already revealed promising perspectives for dental restorative dentistry.

Corrigendum to "Epigallocatechin-3-gallate/mineralization precursors co-delivery hollow mesoporous nanosystem for synergistic manipulation of dentin exposure" [Bioact. Mater. 23 (2023) 394-408].

[This corrects the article DOI: 10.1016/j.bioactmat.2022.11.018.].

Adaptation and validation of the Chinese version of the Sleep Quality Questionnaire.

STUDY OBJECTIVES: Sleep quality is essential to health. The current study aimed to adapt and validate the Sleep Quality Questionnaire (SQQ) into Chinese language. METHODS: The Chinese version of the SQQ (SQQ-C) was created following the guidelines for cross-cultural adaptation. Compliant with the COSMIN methodology, baseline data (N = 13,325) examined three validity domains and internal consistency, including content validity using the content validity index (CVI) and the cognitive debriefing and focus group (relevance, comprehensiveness and comprehensibility), construct validity using structural validity and cross­sectional measurement invariance, and criterion validity using concurrent/convergent validity. Follow-up data (N = 3410) gathered within a mean of 168 (167-207) h interval were used to additionally assess longitudinal measurement invariance and test-retest reliability using intraclass correlation coefficient (ICC). RESULTS: Scale-level CVI/Average was equal to 0.922; Item-level CVIs ranged from 0.889 to 1.000 (excellent), except for item 2 (0.556-fair). A panel of local experts and local participants during cognitive debriefing and focus group stated that it had sufficient relevance and comprehensibility but a slight deficiency in comprehensiveness. Confirmatory factor analysis indicated a stable two-factor structure encompassing Daytime Sleepiness Subscale and Sleep Difficulty Subscale from baseline to follow-up data. The SQQ-C-9 (without item 2) outperformed the SQQ-C-10 (full form). The SQQ-C-9 provided evidence of measurement invariance (strict) across subgroups (cohorts, gender, and age) and across time. The SQQ-C was negatively correlated with the Chinese Nonrestorative Sleep Scale and the Chinese Sleep Condition Indicator. Cronbach's alpha (α), McDonald's Omega (ω), and ICC, respectively, ranged from 0.712 to 0.838, 0.723 to 0.840, and 0.738 to 0.764 for total scale and each subscale. CONCLUSION: The SQQ-C exhibits adequate psychometric properties and a stable two-factor structure, and should enable valuable assessments of sleep quality in clinical and research settings.

Epigallocatechin-3-gallate/mineralization precursors co-delivery hollow mesoporous nanosystem for synergistic manipulation of dentin exposure.

As a global public health focus, oral health plays a vital role in facilitating overall health. Defected teeth characterized by exposure of dentin generally increase the risk of aggravating oral diseases. The exposed dentinal tubules provide channels for irritants and bacterial invasion, leading to dentin hypersensitivity and even pulp inflammation. Cariogenic bacterial adhesion and biofilm formation on dentin are responsible for tooth demineralization and caries. It remains a clinical challenge to achieve the integration of tubule occlusion, collagen mineralization, and antibiofilm functions for managing exposed dentin. To address this issue, an epigallocatechin-3-gallate (EGCG) and poly(allylamine)-stabilized amorphous calcium phosphate (PAH-ACP) co-delivery hollow mesoporous silica (HMS) nanosystem (E/PA@HMS) was herein developed. The application of E/PA@HMS effectively occluded the dentinal tubules with acid- and abrasion-resistant stability and inhibited the biofilm formation of Streptococcus mutans. Intrafibrillar mineralization of collagen fibrils and remineralization of demineralized dentin were induced by E/PA@HMS. The odontogenic differentiation and mineralization of dental pulp cells with high biocompatibility were also promoted. Animal experiments showed that E/PA@HMS durably sealed the tubules and inhibited biofilm growth up to 14 days. Thus, the development of the E/PA@HMS nanosystem provides promising benefits for protecting exposed dentin through the coordinated manipulation of dentin caries and hypersensitivity.

Experimental two-step universal adhesives bond durably in a challenging high C-factor cavity model.

OBJECTIVES: To determine the bonding effectiveness of experimental 2-step universal adhesives (UAs) to high C-factor class-I cavity-bottom dentin and to assess the potential bond-strength contribution of an additional flowable composite layer. METHODS: Three experimental 2-step UA formulations, involving the application of a 10-MDP-based primer followed by a hydrophobic adhesive resin with a 15-to-20-µm film thickness and differing only for filler, referred to as BZF-21 (silica and bioglass filler), BZF-29 (silica filler) and BZF-29_hv (higher silica-filler loading resulting in a higher viscosity), all prepared by GC, along with three representative commercial adhesives, Clearfil SE Bond 2 (C-SE2, Kuraray Noritake), G-Premio Bond (G-PrB, GC) and OptiBond FL (Opti-FL, Kerr), were comparatively investigated for their 'immediate' and 'aged' (50,000 thermocycles) micro-tensile bond strength (µTBS), when applied either in etch-and-rinse (E&R) or self-etch (SE) mode, to high C-factor class-I cavity-bottom dentin (n = 10; 10 experimental groups). Four additional experimental groups involved the extra application of the flowable composite G-ænial Universal Flo (GC), employed as an intermediate liner in combination with the adhesives BZF-29 and G-PrB and again applied both in E&R or SE mode. Statistical analysis was performed using linear mixed-effects (LME) modelling and linear regression analysis (p < 0.05). RESULTS: All 2-step UAs performed similarly when compared to the gold-standard E&R Opti-FL and SE C-SE2 adhesives, except for the aged µTBS of BZF-29_hv applied in E&R mode, and significantly outperformed the 1-step UA G-PrB. Significant reduction in µTBS upon aging was only recorded for 2-step UAs applied in E&R mode. The extra flowable composite layer significantly improved G-PrB's µTBS. SIGNIFICANCE: The experimental 2-step UAs revealed favorable bonding performance in the challenging high C-factor class-I cavity model, comparable to that of the multi-step gold-standard E&R and SE adhesives and superior to that of the 1-step UA investigated. An additionally applied flowable composite layer compensated for the lower bonding effectiveness of the 1-step UA in the high C-factor cavity model.

Enhancing dentin bonding quality through Acetone wet-bonding technique: a promising approach.

Objective: This paper aimed to assess the impact of the acetone wet-bonding (AWB) technique on dentin bonding and to investigate its potential underlying mechanisms. Materials and Methods: Caries-free third molars were sliced, ground, etched, water-rinsed. Then the specimens were randomly allocated to four groups according to the following pretreatments: 1. water wet-bonding (WWB); 2. ethanol wet-bonding (EWB); 3. 50% (v/v) acetone aqueous solution (50%AWB); 4. 100% acetone solution (AWB). Singlebond universal adhesive was then applied and composite buildups were constructed. The microtensile bond strength (MTBS), failure modes and interface nanoleakage were respectively evaluated after 24 h of water storage, 10,000 times of thermocycling or 1-month collagenase ageing. In situ zymography and contact angle were also investigated. Results: Acetone pretreatment preserved MTBS after thermocycling or collagenase ageing (p < 0.05) without affecting the immediate MTBS (p > 0.05). Furthermore, AWB group manifested fewer nanoleakage than WWB group. More importantly, the contact angle of the dentin surfaces decreased significantly and collagenolytic activities within the hybrid layer were suppressed in AWB group. Conclusion: This study suggested that the AWB technique was effective in enhancing the dentin bond durability by increasing the wettability of dentin surface to dental adhesives, removing residual water in the hybrid layer, improving the penetration of adhesive monomer, and inhibiting the collagenolytic activities. Clinical significance: The lifespan of adhesive restorations would be increased by utilization of acetone wet-bonding technique.

Enhancing adhesive-dentin interface stability of primary teeth: From ethanol wet-bonding to plant-derived polyphenol application.

OBJECTIVES: To investigate whether the adhesive-dentin interface stability of primary teeth would be enhanced by epigallocatechin-3-gallate (EGCG) with ethanol wet-bonding. METHODS: Non-caries primary molars were sliced to achieve a flat dentin surface and etched then randomly distributed into five groups in accordance with different treatments: group 1, no treatment; group 2, applying absolute ethanol wet-bonding for 60 s; groups 3-5, applying 0.1%, 0.5%, and 1% (w/v) EGCG-incorporating ethanol wet-bonding (0.1%, 0.5%, and 1% EGCG) for 60 s. Singlebond universal adhesive was then applied followed by resin composite construction. Microtensile bond strength, fracture mode, and nanoleakage at adhesive-dentin interface were evaluated after 24 h of water storage or 10,000 times of thermocycling. Zymography of hybrid layer, biofilm formation of Streptococcus mutans by CLSM, FESEM, and MTT test, and cytotoxicity by CCK-8 assay were respectively assessed. RESULTS: Irrespective of thermocycling, the dentin bond strength was preserved with reduced nanoleakage in the 0.5% and 1% EGCG groups. Furthermore, the activity of endogenous proteases and the growth of Streptococcus mutans biofilm were inhibited after treatment with 0.5% and 1% EGCG/ethanol solutions (groups 4 and 5). CCK-8 results of the 0.1% and 0.5% EGCG groups showed acceptable biocompatibility. CONCLUSIONS: Treatment by EGCG/ethanol solutions effectively enhanced the bond stability of primary teeth at the adhesive-dentin interface. CLINICAL SIGNIFICANCE: Synergistic application of EGCG and ethanol wet-bonding suggesting a promising strategy to improve dentin bonding durability with bacterial biofilm inhibition, thus increasing resin-based restorations' service life in primary dentition.

Dentin conditioned with a metal salt-based conditioner.

OBJECTIVES: Universal adhesives (UAs) can optionally be applied in either an etch-and-rinse (E&R) or self-etch (SE) bonding mode. As the preferred bonding mode differs for enamel versus dentin, a universal conditioner for both enamel and dentin in replacement of the relatively aggressive phosphoric-acid etchant remains desirable. This study aimed to test if a metal salt-based etchant (ZrO(NO3)2) provides as durable bonding to dentin as a classic E&R or SE bonding mode METHODS: Before applying the UA Adhese Universal ('AdU'; Ivoclar Vivadent) to bur-cut dentin of 24 teeth (n = 8), dentin was conditioned with either (1) an experimental metal salt-based conditioner ('ZON'; Ivoclar Vivadent) or (2) 37% phosphoric acid (Total Etch gel, Ivoclar Vivadent), representing a classic 'E&R' mode; (3) a third experimental group involved AdU applied in SE mode. Bonding effectiveness was determined in terms of immediate ('1w') and aged ('50k' TC) micro-tensile bond strength (µTBS) to bur-cut dentin. Adhesive-conditioned dentin interfacial interactions were characterized by S/TEM. RESULTS: Linear mixed-effects modeling revealed significantly higher immediate µTBS to dentin of ZON_AdU than E&R_AdU, while ZON_AdU performed not significantly different from SE_AdU. No significant differences were found between the three experimental groups after 50k TC (aged µTBS). S/TEM disclosed less exposure of dentinal collagen fibrils when AdU was bonded upon ZON etching than when applied in E&R mode. Moreover, ZON resulted in more hydroxyapatite (HAp) crystals remaining at the bottom of the hybrid layer, while dentinal tubule orifices remained nearly fully closed, by which hardly any resin tags were formed. SIGNIFICANCE: The alternative metal salt-based conditioner revealed at dentin a more HAp-protected hybrid layer with less exposure of collagen fibrils, while a comparable bond strength was obtained to that with a phosphoric-acid E&R as well as with an SE (no conditioner) bonding mode. These findings confirm that the metal salt-based conditioner can be considered as a suitable alternative (enamel/)dentin conditioner to classic phosphoric acid employed in an E&R bonding mode.

Enhancing resin-dentin bond durability using a novel mussel-inspired monomer.

Numerous approaches have been developed to improve the resin-dentin bond performance, among which the bio-application of mussel-derived compounds have drawn great attention recently. To assess the performance of N-(3,4-dihydroxyphenethyl)methacrylamide (DMA), a mussel-derived compound, as a functional monomer in dental adhesive, its potential property to cross-link with dentin collagen and polymerize with adhesive will first be evaluated by transmission electron microscopy (TEM), attenuated total reflectance technique of Fourier transform infrared (ATR-FTIR), and atomic force microscopy (AFM) via Peakforce QNM mode. After validating the influence of DMA on collagen and adhesive separately, the overall performance of DMA/ethanol solution as a primer in dentin bonding was examined using micro-tensile bond strength (µTBS) testing, fracture pattern observation, and nanoleakage evaluation both immediately and after 10,000 times thermocycling aging. The inhibitory effect of DMA on endogenous metalloproteinases (MMPs) was evaluated by in situ zymography using confocal laser scanning microscopy (CLSM) and the cytotoxicity of DMA was evaluated using cell counting kit-8. Results demonstrated that DMA successfully cross-linked with dentin collagen via non-covalent bonds and had no influence on the polymerization and mechanical properties of the adhesive. Furthermore, even after 10,000 times thermocycling aging, the µTBS and nanoleakage expression of the DMA-treated groups showed no significant change compared with their immediate values. In situ zymography revealed reduced endogenous proteolytic activities after the application of DMA, and no cytotoxicity effect was observed for DMA concentration up to 25 â€‹µmol/L. Thus, DMA could be used as a novel, biocompatible functional monomer in dentin bonding.

Evaluation of resveratrol-doped adhesive with advanced dentin bond durability.

OBJECTIVES: This paper aimed to evaluate the influence of resveratrol-doped adhesive on the durability and antibiofilm capability of dentin bonding. METHODS: Experimental adhesives were prepared by incorporating resveratrol into a universal adhesive at concentrations of 0 (control), 0.1, 1, and 10 mg/mL. The microtensile bond strength, fracture modes, and adhesive-dentin interface nanoleakage were assessed after 24 h of water storage, 10,000 times of thermocycling or 1-month of collagenase ageing. Relevant antibiofilm capability on Streptococcus mutans (S. mutans), in situ zymography, degree of conversion, and cytotoxicity of resveratrol-doped adhesives were also determined. RESULTS: Irrespective of thermocycled or collagenase ageing, the resveratrol-doped adhesive (1 mg/mL) maintained the bond strength and reduced the nanoleakage expression. Meanwhile, the inhibitory ability on endogenous protease activity and S. mutans biofilm formation with acceptable biocompatibility were obtained. CONCLUSIONS: This study suggested that the resveratrol-doped adhesive achieved effective improvement on dentin bond durability and secondary caries management. CLINICAL SIGNIFICANCE: The application of the resveratrol-doped adhesive indicates promising benefits to increase the lifetime of composite restorations.

Optimizing glass-ceramic bonding incorporating new silane technology in an experimental universal adhesive formulation.

OBJECTIVE: Incorporating silane-coupling agent into universal adhesives (UAs) to simplify adhesive luting of glass-ceramic restorations appeared ineffective due to silane's instability in an acidic aqueous solution. This study aimed to evaluate new silane technology added to an experimental UA to be bonded to glass ceramics without separate prior silanization. METHODS: Combined silane technology, consisting of 3-(aminopropyl)triethoxysilane (APTES) and γ-methacryloxypropyltriethoxysilane (γMPTES), was incorporated into an experimental UA formulation, being referred to as ADH-XTE (3M Oral Care). Immediate and aged shear bond strength (SBS) of ADH-XTE onto as-milled ('AM'), tribochemical silica-coated ('TSC'), HF-etched ('HF'), and mirror-polished ('MP') glass-ceramic CAD/CAM blocks (IPS e.max CAD) with/without separate silanization was measured (n = 10/group). The control adhesives included Scotchbond Universal ('SBU') and Scotchbond 1 XT ('SB1-XT'). The glass-ceramic surface topography and the fractography of the SBS-debonded specimens were observed by SEM. RESULTS: Without separate prior silanization, the experimental UA ADH-XTE, containing combined APTES/γMPTES silane technology, significantly outperformed the glass-ceramic bonding efficiency of its silane-containing SBU precursor, while it performed equally effective as SBU applied with prior silanization. Upon aging, significant reduction in SBS was recorded when ADH-XTE was bonded to TSC glass-ceramic surfaces (p < 0.05), while not to HF ones. Notably, the lowest SBS was obtained when the UAs were bonded to AM and MP glass-ceramic surfaces, in particular when applied without separate prior silanization (p < 0.05). SIGNIFICANCE: The glass-ceramic bonding capacity of the new combined APTES/γMPTES silane-containing UA ADH-XTE surpassed that of its SBU precursor. HF etching remains needed to durably bond to glass-ceramics.

Extra Bonding Layer Compensates Universal Adhesive's Thin Film Thickness.

PURPOSE: Universal adhesives (UAs) are applied in 2-step etch-and-rinse (2-E&R) or 1-step self-etch (1-SE) mode. This study investigated whether three UAs could benefit from a highly filled extra bonding layer (EBL), turning them into 3-E&R and 2-SE UAs, respectively, thus also compensating for the commonly thin film thickness of UAs. MATERIALS AND METHODS: Microtensile bond strength (µTBS) to bur-cut dentin of Clearfil Universal Bond Quick (C-UBq, Kuraray Noritake), G-Premio Bond (G-PrB, GC) and Prime&Bond Active (P&Ba, Dentsply Sirona), applied in E&R and SE mode without/with the adhesive resin (EBL) of OptiBond FL (Opti-FL_ar, Kerr), was compared to that of the 3-E&Ra OptiBond FL (Opti-FL; Kerr), which was also employed in 2-SE mode. As a cross reference, the SE primer of Clearfil SE Bond 2 (Kuraray Noritake) was combined with Opti-FL_ar (C-SE2/Opti-FL) and again applied in 2-SE and 3-E&R mode. µTBS was measured after 1 month of water storage (37°C) and additional 25,000 and 50,000 thermocycles (TC). All µTBS were statistically analyzed using three different linear mixed-effects models with specific contrasts (p < 0.05). RESULTS: Overall, the four parameters (adhesive, bonding mode, aging, EBL) significantly influenced µTBS. G-PrB and P&Ba benefited from EBL when applied in both E&R and SE bonding modes. In E&R mode, P&Ba generally revealed the highest µTBS; C-UBq presented an intermediate and G-PrB the lowest µTBS. No significant differences were found between different bonding modes. C-SE2/Opti-FL outperformed Opti-FL in 3-E&R and 2-SE_1 month/25k. CONCLUSION: The overall benefit of EBL on the 1-month and TC-aged bonding efficacy differed for the different UAs tested.

New perspective to improve dentin-adhesive interface stability by using dimethyl sulfoxide wet-bonding and epigallocatechin-3-gallate.

OBJECTIVES: To determine whether dentin-adhesive interface stability would be improved by dimethyl sulfoxide (DMSO) wet-bonding and epigallocatechin-3-gallate (EGCG). METHODS: Etched dentin surfaces from sound third molars were randomly assigned to five groups according to different pretreatments: group 1, water wet-bonding (WWB); group 2, 50% (v/v) DMSO wet-bonding (DWB); groups 3-5, 0.01, 0.1, and 1 wt% EGCG-incorporated 50% (v/v) DMSO wet-bonding (0.01%, 0.1%, and 1%EGCG/DWB). Singlebond universal adhesive was applied to the pretreated dentin surfaces, and composite buildups were constructed. Microtensile bond strength (µTBS) and interfacial nanoleakage were respectively examined after 24 h water storage or 1-month collagenase ageing. In situ zymography andStreptococcus mutans (S. mutans) biofilm formation were also investigated. RESULTS: After collagenase ageing, µTBS of groups 4 (0.1%EGCG/DWB) and 5 (1%EGCG/DWB) did not decrease (p > 0.05) and was higher than that of the other three groups (p < 0.05). Nanoleakage expression of groups 4 and 5 was less than that of the other three groups (p < 0.05), regardless of collagenase ageing. Metalloproteinase activities within the hybrid layer in groups 4 and 5 were suppressed. Furthermore, pretreatment with 1%EGCG/DWB (group 5) efficiently inhibited S. mutans biofilm formation along the dentin-adhesive interface. SIGNIFICANCE: This study suggested that the synergistic action of DMSO wet-bonding and EGCG can effectively improve dentin-adhesive interface stability. This strategy provides clinicians with promising benefits to achieve desirable dentin bonding performance and to prevent secondary caries, thereby extending the longevity of adhesive restorations.

Zinc-Calcium-Fluoride Bioglass-Based Innovative Multifunctional Dental Adhesive with Thick Adhesive Resin Film Thickness.

Apart from producing high bond strength to tooth enamel and dentin, a dental adhesive with biotherapeutic potential is clinically desirable, aiming to further improve tooth restoration longevity. In this laboratory study, an experimental two-step universal adhesive, referred to as Exp_2UA, applicable in both the etch-and-rinse (E&R) and self-etch (SE) modes and combining a primer, containing 10-methacryloyloxydecyldihydrogen phosphate as a functional monomer with chemical binding potential to hydroxyapatite, with a bioglass-containing hydrophobic adhesive resin, was multifactorially investigated. In addition to primary property assessment, including measurement of bond strength, water sorption, solubility, and polymerization efficiency, the resultant adhesive-dentin interface was characterized by transmission electron microscopy (TEM), the filler composition was analyzed by energy-dispersive X-ray spectroscopy, and the bioactive potential of the adhesive was estimated by measuring the long-term ion release and assessing its antienzymatic and antibacterial potential. Four representative commercial adhesives were used as reference/controls. Application in both the E&R and SE modes resulted in a durable bonding performance to dentin, as evidenced by favorable 1 year aged bond strength data and a tight interfacial ultrastructure that, as examined by TEM, remained ultramorphologically unaltered upon 1 year of water storage aging. TEM revealed a 20 µm thick hydrophobic adhesive layer with a homogeneous bioglass filler distribution. Adequate polymerization conversion resulted in extremely low water sorption and solubility. In situ zymography revealed reduced endogenous proteolytic activity, while Streptococcus mutans biofilm formation was inhibited. In conclusion, the three-/two-step E&R/SE Exp_2UA combines the high bonding potential and bond degradation resistance with long-term ion release, rendering the adhesive antienzymatic and antibacterial potential.

Bonding Efficacy of a New Self-Adhesive Restorative onto Flat Dentin vs Class-I Cavity-bottom Dentin.

PURPOSE: This study investigated the bonding efficacy of a new so-called self-adhesive composite hybrid onto flat (FLAT) and high C-factor class-I cavity-bottom (CAVITY) dentin. MATERIALS AND METHODS: The immediate and aged (50,000 thermocycles) microtensile bond strength (µTBS) to FLAT and CAVITY dentin of the experimental self-adhesive bulk-fill restorative (K-0180 ASAR pilot [ASAR-pilot], Dentsply Sirona) was compared to that of two universal adhesives applied in self-etch mode and combined with a bulk-fill composite (Prime&Bond Elect/QuiXfil [P&Be/QuiXF], Prime&Bond Active/QuiXfil [P&Ba/QuiXF], both Dentsply Sirona), two pre-conditioned materials (Activa Bioactive-Restorative [Activa], Pulpdent; Fuji II LC Improved [Fuji2LC], GC); and one bulk-fill glass-hybrid restorative (Equia Forte Fil [EquiaF], GC). Statistically significant differences were recorded using Welch's ANOVA with Games-Howell contrast (p < 0.05). RESULTS: No significant difference in immediate µTBS was recorded when the restorative materials were applied onto FLAT dentin, except for Activa_FLAT and EquiaF_FLAT. When bonded to CAVITY dentin, the significantly highest µTBS was recorded for Fuji2LC_CAVITY (layer filled), and was not significantly different only from P&Ba/QuiXF_CAVITY. Upon aging, the highest µTBS to flat dentin was achieved by ASAR-pilot_FLAT, which was not significantly different from P&Be/QuiXF_FLAT and Fuji2LC_FLAT. No significant difference between immediate and aged µTBS was recorded for ASAR-pilot when bonded onto FLAT or CAVITY dentin; the latter, however, was associated with low bond strength. CONCLUSION: Favorable bonding performance was found for the new self-adhesive bulk-fill composite hybrid ASAR-pilot when bonded to flat dentin. However, much lower bond strength was recorded when ASAR-pilot was bonded to high C-factor cavity-bottom dentin.

Structural/Chemical Characterization and Bond Strength of a New Self-Adhesive Bulk-fill Restorative.

PURPOSE: The material structure and chemical elemental composition of a new self-adhesive composite hybrid were investigated. The bonding performance when applied on flat (FLAT) vs high C-factor class-I cavity-bottom (CAVITY) dentin and in light-cure (LC) vs self-cure (SC) mode was determined. MATERIALS AND METHODS: The self-adhesive bulk-fill composite Surefil One (Su-O; Dentsply Sirona) was compared with the resin-modified glass-ionomer Fuji II LC Improved (Fuji2LC; GC) and the ion-releasing alkasite material Cention N (CentionN; Ivoclar Vivadent). The material structure was examined with SEM and TEM, while the chemical elemental composition was analyzed using EDS. The immediate and aged microtensile bond strength (µTBS) of Su-O_LC/SC was compared to that of Fuji2LC applied without any pre-treatment, and to that of CentionN applied following bonding with Adhese Universal (AU) (Ivoclar Vivadent) in self-etch mode (AU/CentionN). All restorative materials were bonded onto FLAT and CAVITY dentin. Statistical analysis was performed with the Kruskal-Wallis nonparametric test. RESULTS: EDS analysis revealed that Su-O was richer in C and P than the reference restorative materials. Applied to FLAT dentin, the significantly highest immediate and aged µTBS were recorded for AU/CentionN, which were not significantly different only from Su-O_LC. Applied to CAVITY dentin, the significantly highest immediate µTBS was recorded for AU/CentionN, which did not differ significantly only from Su-O_SC. Su-O_LC bonded to CAVITY dentin suffered from a high incidence of pre-test failures. CONCLUSION: While Su-O_LC bonded effectively and durably to FLAT dentin, Su-O_SC bonded more favorably than Su-O_LC in class-I cavities, which was probably related to shrinkage stress variously challenging the respective bond.

Bonding to enamel using alternative Enamel Conditioner/etchants.

OBJECTIVE: Enamel bond durability of three new alternative etchants combined with three representative adhesives was determined. METHODS: The 'immediate' and 'aged' micro-tensile bond strength (µTBS) of the 3-step etch&rinse adhesive OptiBond FL ('O-FL', Kerr), 2-step self-etch (SE) adhesive Clearfil SE Bond 2 ('C-SE2', Kuraray Noritake) and universal adhesive Adhese Universal ('ADU', Ivoclar Vivadent) were measured when bonded to enamel following either a proprietary organic acid-containing Enamel Conditioner ('EC', Shofu), a phosphoric-acid monomer-containing Multi Etchant ('ME', Yamakin: 10-methacryloyloxy tetraethylene glycol dihydrogenphosphate or MTEGP), or a metal salt-based ZON etchant ('ZON', Ivoclar Vivadent: ZrO(NO3)2). All alternative etchants were used in replacement of phosphoric acid, the latter (K-Etchant, Kuraray Noritake) also used with O-FL and ADU, in addition to C-SE2 that was solely used in SE mode (controls). The enamel-etching patterns and de-bonded fracture surfaces were examined by SEM, while the interfaces with enamel were ultra-morphologically characterized by TEM. RESULTS: No statistically significant difference in immediate and aged µTBS, obtained by combining the three alternative etchants with the three adhesives, was recorded as compared with the respective controls, except for ME combined with O-FL. Upon aging, significant reduction in µTBS was recorded for the ME/C-SE2 and ME/ADU combinations. The percentage of adhesive failures increased with aging. SEM revealed similar etching patterns produced by EC and ZON as by classic phosphoric-acid etching, for which also numerous micro-resin tags at the adhesive-enamel interface were disclosed. SIGNIFICANCE: Durable bonding to enamel was generally obtained for all etchant/adhesive combinations with the exception of the ME/O-FL combination.