Effect of silver diamine fluoride on the longevity of the bonding properties to caries-affected dentine.

OBJECTIVES: This study aimed to evaluate the adhesive properties in dentine after the application of silver diamine fluoride (SDF) on carious dentine lesions immediately and after 2 years of water storage. METHODS: 96 human molars used were subjected to artificial dentine caries production, and then randomly divided into 12 experimental groups according to 1. application of an SDF solution (carious dentine lesion without SDF treatment [control], with 12 % silver diamine fluoride [SDF 12 %] or 38 % silver diamine fluoride [SDF 38 %]); 2. Universal adhesives (Clearfil Universal Bond Quick [CUQ] and Single Bond Universal [SBU]); 3. adhesive strategy (etch-and-rinse [ER] and self-etch [SE]). After restoration, the specimens were sectioned and submitted to the microtensile bond strength test (µTBS) and energy-dispersive X-ray spectrometry analysis (SEM/EDX). All tests were performed immediately and after 2 years of water storage. Data from the µTBS were analyzed using four-way ANOVA and Tukey's test (α = 0.05). RESULTS: Only the interaction of factors 'SDF' vs 'time' was significant (p = 0.03). After 2 years of storage, the groups where SDF was applied showed higher µTBS values compared to the control group. No significant decrease in µTBS values was observed for SBU when comparing immediate and 2-year results, but a significant reduction in µTBS values was observed after 2 years for CUQ. CONCLUSION: Independent of the adhesive strategy, the use of SDF may be a promising alternative to maintain the bonding of universal adhesives to carious dentinal lesions. CLINICAL SIGNIFICANCE: This study may clarify and support clinicians regarding the longevity of resin-based restoration in caries-affected dentine treated with silver diamine fluoride.

Glass-ionomer and calcium silicate-based cements interactions with human dentine in health and disease: Two-photon fluorescence microscopy and Raman spectroscopy analysis.

OBJECTIVES: To investigate the potential mineralising effects of calcium silicate-based dentine replacement material (Biodentine™) in comparison with glass-ionomer cement (GIC) (Fuji IX™) on different human dentine substrates using a multimodal non-invasive optical assessment. METHODS: Cements were applied on artificially demineralised or naturally carious dentine and stored for 4 weeks in phosphate-rich media +/- tetracycline used for mineralisation labelling. Interfacial dentine was examined from the same sample and location before and after aging using two-photon fluorescence microscopy, fluorescence lifetime imaging (FLIM) and second harmonic generation (SHG) imaging. Additionally, Raman spectroscopy was used to detect changes in the mineral content of dentine. RESULTS: Significant changes in the fluorescence intensity and lifetime were detected in partially demineralised dentine and caries-affected dentine underneath both tested cements, after storage (p < 0.001). This was associated with a significant increase in the mineral content as indicated by the increased intensity of the phosphate Raman peak located at 959 cm-1 (p < 0.0001). Caries-infected dentine showed significant fluorescence changes under Biodentine™ after storage (p < 0.001), but not under GIC (p = 0.44). Tetracycline binding induced a reduction in the fluorescence lifetime with comparable increase in the fluorescence intensity in both cements' groups within the affected dentine (p < 0.001). Significance Two-photon fluorescence microscopy can be used efficiently for non-destructive in-vitro dentine caries characterisation providing a technique for studying the same dentine-cement interface over time and detect changes. Biodentine™ demonstrated comparable remineralising potential to GIC, in addition to inducing remineralisation of caries-infected dentine. This may suggest using Biodentine™ as part of minimally invasive operative dentistry (MID) in caries management.

Disinfection of caries-affected dentin using potassium titanyl phosphate laser, Rose bengal and Ozonated water on shear bond strength of deciduous teeth.

AIM: To assess the efficacy of disinfection of caries-effected dentin (CAD) using KTP laser and different decontamination methods using ozonated water (OW), Rose Bengal photosensitizer (RBP), chlorhexidine (CHX), and Er, YAG laser on the shear bond strength (SBS) of adhesive resin bonded to deciduous teeth. MATERIAL AND METHODS: A total of 50 extracted and radiographically verified carious primary molars were collected and scrutinized according to ICDAS criteria. Specimens were allocated randomly into five groups (n = 10) as per the type of CAD disinfectants. KTP laser, OW, RBP, CHX (control), and Er, YAG laser. After cavity sanitization, a resin adhesive (prime and bond NT) was smeared on the dentinal exterior followed by incremental composite filling. SBS evaluation was performed by employing specimens in the universal testing machine. The debonded surface was assessed under 40x magnification in a stereomicroscope to ascertain fracture mode. Statistical analysis was done by using the ANOVA and the Post Hoc Tukey multiple comparison tests (p < 0.05). RESULTS: The highest SBS was exhibited by group 2 i.e., when OW was employed for CAD disinfection (10.25 ± 0.24 MPa). Whereas, the lowest SBS bond value was unveiled by samples in group 3 when RBP was applied for dentin surface sanitization (7.85 ± 0.59 MPa).CAD disinfection with KTP laser (8.25 ± 0.41 MPa), CHX (8.19 ± 0.73 MPa), and RBP displayed comparable bond values (p > 0.05). CONCLUSION: Ozonated water and Er, YAG laser could be employed as cavity disinfectants in primary teeth as they demonstrated better shear bond strength without jeopardizing the adhesive binding capacity of restorative resins bonded to caries-affected dentin.

Efficacy of chlorhexidine, photosensitizers, green tea extract, and propolis on bond integrity and microleakage of caries-affected dentin: An in-vitro study.

AIM: The current study aimed to evaluate the efficacy of chlorhexidine (CHX), phycocyanin photosensitizer (PC), green tea extract (GTE), and propolis (PP) on the adhesive bond integrity and microleakage of caries-affected dentin (CAD) using etch and rinse adhesive system. MATERIAL AND METHODS: A sum of 80 extracted human mandibular molars was collected and assessed using ICDAS criteria. Randomly CAD samples were treated with different disinfectants (n = 20) each CHX, PC, GTE, and PP. After ensuring disinfection, specimens were rehabilitated with bulk-fill composite resin employing etch and rinse adhesive system. SBS testing was performed by engaging (n=10) specimens in a universal testing machine. Microleakage analysis was performed by using the dye penetration technique.A stereomicroscope under 40× magnification was utilized for analyzing failure modes. Statistical analysis was accomplished by using the ANOVA and Tukey's post hoc tests (p<0.05). RESULTS: Highest bond strength was displayed by CAD disinfection with CHX and bonded to resin cement (15.33 ± 0.14 MPa). Whereas, the lowest SBS bond value was presented by Group 2 dentin surface disinfection with PC. CAD disinfected with GTE, PP and CHX demonstrated comparable SBS(p>0.05). The maximum microleakage score was exhibited when CAD bonded to resin cement disinfected with PP. While the minimum microleakage score was unveiled CAD bonded to resin cement sanitized with CHX CONCLUSION: Caries-affected dentin bonded to resin cement, chlorhexidine exhibited the highest adhesive shear bond strength with a minimal microleakage score using etch and rinse adhesive system.

An in-vitro investigation of the bond strength of experimental ion-releasing dental adhesives to caries-affected dentine after 1 year of water storage.

OBJECTIVE: The aim of this study was to evaluate the bonding performance after 1 year storage of an experimental dental adhesive containing analogues of phosphoproteins and fluoride-doped bioglass (EXP), applied in self-etching (SE) or etch & rinse (ER) mode, to caries-affected dentine after selective caries removal. MATERIALS AND METHODS: Fifty human molars with dentine carious lesions were excavated selectively using CarisolvTM gel and then connected to simulated pulpal pressure system. Teeth were divided randomly into five groups based on the tested materials: EXP-SE, EXP-ER, a resin-modified glass-ionomer cement (RMGIC), a three-step adhesive system (OPT) and a universal adhesive applied in SE mode (UA-SE). The specimens were submitted to different analytical tests (µTBS, SEM fractographic analysis and dye-enhanced confocal microscopy) at baseline (T0) and after 1 year (T1). RESULTS: At T0 there was no difference in bond strength between the tested materials (p>0.05). At T1, EXP-SE and EXP-ER were the only materials to show no significant reduction in bond strength (p<0.05). The SEM showed a clear presence of minerals deposited on the dentine surface after bonding in the EXP-SE and EXP-ER groups. The specimens restored with RMGIC showed no exposure of the dentine surface after failure. The OPT and UA-SE specimens showed clear signs of degradation at the interface. Confocal microscopy imaged mineral precipitation at the interface of the EXP groups. CONCLUSION: Conventional adhesives may have inadequate bonding performance with evident degradation at the dentine-bonded interface over time. Although the RMGIC may present a drop in bond strength after prolonged storage, the bonding interface may result less affected by degradation over time. Innovative ion-releasing adhesives may remineralise the caries-affected dentine and achieve a stable bond over time. CLINICAL SIGNIFICANCE: GIC-based materials may represent an appropriate dentine replacement material after selective chemo-mechanical caries removal rather than conventional adhesive systems.

Current perspectives on dental adhesion: (2) Concepts for operatively managing carious lesions extending into dentine using bioactive and adhesive direct restorative materials.

This article reviews the current concepts for operatively managing carious lesions extending into dentine with minimal removal of tooth structure and restoring with dentine adhesives and direct composite resin. It looks sequentially at the operative steps involved including remineralisation with bioactive cements, bonding to caries-affected dentine including smear-layer modification using HOCl, creation of an acid-base resistance zone,steps to optimise the performance of all-in-one adhesives, and incremental placement of direct composite resin to improve bond strengths to cavity floor dentine. It explores how understanding the phenomenon of colour-shifting at the composite resin-enamel/dentine restoration borders can help in creating near "invisible" restoration margins through a "chameleon" effect. With the increased risks of transmission of Covid-19 when aerosol generating procedures are carried out in Dentistry, following a minimally invasive approach to managing dental caries should be given serious consideration.

Effect of adding ribbond fibres on marginal adaptation in class II composite restorations in teeth with affected dentine.

OBJECTIVE: To evaluate the feasibility and effect on marginal adaptation in class II composite restoration reinforced with polyethylene fibres in teeth with affected dentine using scanning electron microscopy. METHOD AND MATERIAL: Class II cavities with dimension 1.5 +0 .25 pulpal depth and 4 ± 0.25 mm buccolingual width/.were prepared on proximal surfaces extracted human molars or premolar with affected/sound dentine on gingival margin. The etching priming and restorations were done in prepared samples as per manufacture directions. The samples were divided in 2 groups depending on use of ribbond inserts in composite restorative material. Samples were finished, stored in distilled water and then thermocycled manually and then sectioned longitudinally through the restorations. The marginal adaptation was evaluated using scanning electron microscope (SEM). RESULT: The result showed that there was a definite gap all along the interface between caries affected dentine and the composite material in both the groups. The bigger gap was present in group II compared to group I.

Contemporary research findings on dentine remineralization.

Dentine remineralization is important for the treatment of dentine caries and the bonding durability of dentine and resin materials in clinical practice. Early studies of dentine remineralization were mostly based on the classical pathway of crystallization, which involves large-scale deposition of calcium phosphate crystals on collagen and is achieved in a liquid environment containing mineral ions. Results from these studies were unsatisfactory and not suitable for clinical application because they did not simulate the ordering of hydroxyapatite in the collagen fibres of natural teeth. As studies on collagen type I and non-collagenous proteins have advanced, dentine biomimetic remineralization has become a popular research topic and has shifted to processes involving intrafibrillar remineralization, which is more similar to natural tooth formation. The objective of this review was to summarize current theory and research progress as it relates to dentine remineralization.

Adjunctive application of chlorhexidine and ethanol-wet bonding on durability of bonds to sound and caries-affected dentine.

OBJECTIVES: To examine the effect of adjunctive application of chlorhexidine (CHX) and ethanol-wet bonding (EWB) on bond durability and nanoleakage of hydrophobic adhesive to sound (SD) and caries-affected dentine (CAD). METHODS: Dentine surfaces of molars were etched after caries removal and randomly allocated to four groups (n=12). In Groups 1 and 2, dentine surfaces were saturated with either 2 ml of 100% ethanol or 2 ml of ethanol with 2% CHX for 60s. In Groups 3 and 4, dentine surfaces were saturated with either 15 µL of distilled water or 15 µL of distilled water with 2% CHX for 60s. Two coats of primer, followed by neat resin were applied and light-cured for 40s. Resin composite build-ups were placed and bonded specimens were sectioned for bond strength testing after 24 h and 12 months' storage in artificial saliva. Bond strength data were analyzed using 3-way ANOVA and SNK tests. Interfacial nanoleakage was evaluated after 24 h and 12 months using a field-emission scanning electron microscopy and data were analyzed using Kruskal-Wallis test. RESULTS: Significant differences were observed for the three factors: "substrate" (p<0.001), "rewetting agents" (p<0.001) and "time" (p<0.001) on bond strength. Incorporation of 2% CHX to EWB preserved bond strength to SD and CAD and reduced interfacial nanoleakage after 12 months. Incorporation of 2% CHX to WWB also preserved bond strength to SD after ageing. CONCLUSIONS: Incorporation of chlorhexidine to ethanol-wet bonding has an interaction effect on preservation of bond durability to sound and caries-affected dentine. CLINICAL SIGNIFICANCE: Incorporation of chlorhexidine to ethanol-wet bonding with hydrophobic adhesive enhances the success rate of aesthetic bonded restorations.

The effect of caries excavation methods on the bond strength of etch-and-rinse and self-etch adhesives to caries affected dentine.

BACKGROUND: The aim of this study was to evaluate the influence of chemomechanical caries removal and conventional caries excavation on the microtensile bond strength of three different dentine adhesive systems. METHODS: Thirty extracted human mandibular molars with radiographic signs of dental caries extending up to the middle third of dentine were sectioned longitudinally through the centre of the carious lesion in a buccolingual direction to yield two sections. One half of each tooth was excavated by tungsten carbide bur and the other half was chemomechanically treated with Carisolv(®) . Three dentine bonding systems: an etch-and-rinse single bottle adhesive (Single Bond, 3M ESPE); a two bottle, two-step self-etch bonding system (One Coat Self Etching Bond, Coltene Whaledent); and a single-step, single bottle self-etch adhesive (Adper Easy Bond Self-Etch Adhesive, 3M ESPE) were applied and composite build-up was done. The specimens were tested for microtensile bond strength. Data were analysed using two-way analysis of variance and pair-wise multiple comparisons were done using the Holm-Sidak method. RESULTS: The etch-and-rinse adhesive and two bottle self-etch system showed significantly higher bond strength than the single bottle self-etch system. Caries excavation method had no influence on bond strength values. CONCLUSIONS: Carisolv(®) did not affect the microtensile bond strength values of different adhesive systems tested to the caries affected dentine.

Microtensile bond strength and SEM evaluation of total-etch and self-etching adhesives to caries-affected dentine / 实用口腔医学杂志

Objective:To evaluate the microtensile bond strength of total-etch or self-etch adhesives to caries-affected dentine versus normal dentine. Methods:Twenty-four extracted human molars with mesial coronal carious lesions extending into mid-dentin were selected. The softened carious dentine was removed with a slow-speed, carbon-steel bur and Caries Marker was used as guides. Prepared cavity in sound dentine in the distal coronal part of the identical teeth was used as the control. Surfaces were bonded with either Prime&Bond NT, Adper Single Bond 2, Adper Prompt or XenoⅢ,according to manufactures' recommendations. A crown was built up using resin composite(Filtek P60).After storage in water (37 ℃,24 h),teeth were vertically serially sectioned into 1.0 mm thick slabs and trimmed to yield 1 mm2 test area that contained either caries-affected or normal dentine. Then the specimen were tested in tension in an Instron machine at 0.8 mm/min.The bonding interface between the dentine and adhesives was qualitatively evaluated under the observation of scanning electron microscope(SEM). Results:Two total-etch adhesives yielded higher bond strengths than the two self-etching systems. And all the adhesives attained higher strengths in normal than in caries-affected dentine(P

Microtensile bond strengths of three adhesives to normal or caries-affected dentine / 实用口腔医学杂志

0.05),respectively.The fractured adheisive dentin surface was mainly a mixed failue mode.Conclusions:There is no significant difference in the bond strengths of each of the three bonding agents to ND and CAD.