Comparative Evaluation of Microtensile Bond Strength in Three Different Dentin Luting Agents: An In vitro Study.

Aim: Long-term clinical success on indirect restorations is largely determined by bonding efficiency of the luting agent, with adhesion to dentin being the main challenge. Therefore, aim of this study was to assess the microtensile bond strength when using flowable resin composite, preheated resin composite and dual self-adhesive resin cement as dentin luting agents. Materials and Methods: Occlusal thirds of molar teeth were cut and randomly divided into 3 groups to be cemented: RelyX™U200, Filtek™ Z250 XT- preheated to 70° and Filtek Flow™ Z350XT. They were then thermocycled 5000 times between 5+/-2°C and 55+/-2°C. Subsequently, 10 microbars per group were prepared. The 30 samples were placed in saline solution for 24 hours at room temperature prior to microtensile test. This was performed with a digital universal testing machine at a crosshead speed of 0.5 mm/min. The bond strength values obtained were analyzed in Megapascals (MPa). Measures of central tendency such mean and measures of dispersion such standard deviation were used. In addition, the Kruskall Wallis non-parametric test with Bonferroni post hoc test was applied, considering a significance value of 5% (P < 0.05), with type I error. Results: The dentin microtensile bond strengths of preheated resin composite, flowable resin composite and dual self-adhesive cement were 6.08 ± 0.66 Mpa, 5.25 ± 2.60Mpa and 2.82 ± 1.26Mpa, respectively. In addition, the preheated resin composite exhibited significantly higher microtensile bond strength compared to the dual self-adhesive cement (P < 0.001). While the flowable resin composite showed no significant difference with the dual self-adhesive cement (P = 0.054) and the preheated resin composite (P = 0.329). Conclusions: The microtensile bond strength in dentin was significantly higher when using a preheated resin composite at 70°C as a luting agent compared to dual self-adhesive cement. However, the preheated resin composite showed similar microtensile bond strength compared to the flowable resin composite.

Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.

OBJECTIVES: In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability. METHODS: CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups. RESULTS: NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths. DISCUSSION: Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term. SIGNIFICANCE: NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques.

Influence of resin-coating techniques on the marginal adaptation and the bond strengths of CAD/CAM-fabricated hybrid ceramic inlays.

This study aimed to evaluate the effects of different resin-coating technique strategies and dual-cure resin luting materials on proximal marginal adaptation and the microtensile bond strengths (µTBSs) of CAD/CAM hybrid ceramic inlays. Extracted human molars were classified into four groups, depending on the coating technique: No coating (None), single coating (1-coating), double coating (2-coating), and flowable resin-coating (Combination). The inlays were bonded with one of the three materials: Panavia V5 (V5), Rely X Ultimate (RXU), and Calibra Ceram (CC). The differences with regard to adaptation were not significant. In the case of µTBS data for V5, no significant differences were observed, whereas for RXU, µTBS values for Combination statistically exceeded those for None and 1-coating. For CC, µTBS values for Combination statistically exceeded those for None, 1-coating, and 2-coating. The coating techniques did not influence the adaptation but influenced the bond strength, and Combination performed the best.

Comparative bonding performance of coronal dentin disks and CAD/CAM resin composite disks for biological restoration: The impact of resin-coating technique.

This study evaluated the bonding performance of coronal dentin disks, designed for biological restoration, and CAD/CAM resin composite disks when bonded to flat dentin surfaces using dual-cure resin cements, with and without a resin-coating (RC) technique. Three distinct groups were established within the non-RC group, each using one of the two types of resin cements in a self-adhesive mode: one-step self-etch adhesive (1-SEA) without light-cure, 1-SEA with light-cure, and a separate group using an alternate cement. Within the RC group, a subgroup was established for each cement. The microtensile bond strength (µTBS) of the disk-dentin beam was tested after 0 and 10,000 thermocycles in a 5°C/55°C. No significant µTBS difference was observed among the non-RC groups. However, when using RC, the µTBSs of coronal dentin disks significantly exceeded those of CAD/CAM resin composite disks. Thermocycle aging did not affect µTBS in any of the bonding methods, except in self-adhesive mode.

Advanced statistical analyses to reduce inconsistencies in bond strength data focused on donor factors: A six-factor analysis using linear mixed and nonlinear regression models.

PURPOSE: This study aimed to investigate the effects of the age and sex of tooth donors on dentin bond strength. METHODS: A total of 38 extracted teeth (12 male and 26 female donors; age range: 17-82 years) were used in this study. In addition to donor age and sex, four other microtensile bond strength (µTBS) test specimen factors were evaluated: dentin position, bonding area, presence of voids at the interface, and computed tomography (CT) values of dentin. The µTBS was measured immediately (24 h) and 6 months after storage in water. After the µTBS testing, linear mixed and nonlinear regression models were used to analyze the effects of these factors on the µTBS data. RESULTS: The results from the linear mixed model revealed that the bonding area (P = 0.02), presence of voids at the interface (P = 0.04), and storage time (P < 0.001) significantly affected bond strength. In contrast, no correlation was observed between the µ TBS and dentin position (P = 0.08) or sex (P = 0.07). The results of the nonlinear regression model with robust variance-covariance estimators revealed that age significantly affected bond strength (P < 0.001). In addition, a significant positive correlation was found between µTBS and age (P < 0.001), with nonlinearity (P = 0.002). However, no correlation was observed between the µTBS and CT values (P = 0.69) without nonlinearity (P = 0.39). CONCLUSIONS: These findings suggest that bond strength increases with age until 60 years but not afterward.

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.

Bond Strength, Microleakage, Microgaps, and Marginal Adaptation of Self-adhesive Resin Composites to Tooth Substrates with and without Preconditioning with Universal Adhesives.

PURPOSE: This study investigated and compared the bond strengths, microleakage, microgaps, and marginal adaptation of self-adhesive resin composites (SAC) to dentin with or without universal adhesives. MATERIALS AND METHODS: Dentin surfaces of 75 molars were prepared for shear and microtensile bond strength testing (SBS and µTBS). Silicon molds were used to build up direct restorations using the following materials to form 5 groups: 1. Surefil One; 2. Prime&Bond active Universal Adhesive + Surefil One; 3. Vertise Flow; 4. OptiBond Universal + Vertise Flow; 5. Scotchbond Universal + Filtek Z500 (control group). Bonded specimens were thermocycled 10,000x before being tested either for SBS or µTBS using a universal testing machine at a crosshead speed of 0.5 mm/min. Direct mesial and distal class-II cavities were created on 100 sound premolars, with the gingival margin of distal cavities placed below CEJ and restored according to the five groups. After thermocycling, microleakage scores were assessed following immersion of restored premolars in 2% methylene blue dye for 24 h, while marginal gaps and adaptation percentages were investigated on epoxy resin replicas under SEM at magnifications of 2000X and 200X, respectively. Results were statistically analyzed with parametric and non-parametric tests as applicable, with a level of significance set at α = 0.05. RESULTS: Bond strengths, microleakage scores, microgaps, and percent marginal adaptation of Surefil One and Vertise Flow were significantly (p < 0.001) inferior to the control group. Dentin preconditioning with universal adhesives significantly increased the study parameter outcomes of Surefil One and Vertise Flow, yet they were still significantly below the performance of the control group. CONCLUSION: Conventional resin composite outperformed the SAC whether applied solely or in conjunction with their corresponding universal adhesives.

Dentin adhesion of bulk-fill composites and universal adhesives in class I-cavities with high C-factor.

OBJECTIVES: The aim of this study was to compare the dentin adhesion of bulk-fill composites in high C-factor class I-cavities before and after thermocycling to a control group using incremental layering technique. METHODS: A standardized class I-cavity was prepared into 195 human molars, then different universal adhesives were applied either in self-etch or etch & rinse mode, and the cavity was filled according to each materials application protocol. The material combinations used were a conventional layered composite as control, the respective bulk-fill product, two other bulk-fill composites made by different manufacturers, with one of them being tested using two different polymerization times. Furthermore, one thermoviscous bulk-fill composite and one self-adhesive restorative were examined of which the latter can only be applied in self-etch mode. In each group the dentin adhesion to the cavity bottom was measured using microtensile bond strength test initially (24 h water storage) and after thermocycling. All results were statistically analyzed using STATA 17.0. RESULTS: The statistical analysis showed significant differences between the control and the experimental groups (p < 0.001). The highest mean bond strength before (14.8 ± 10.7 MPa) and after aging (14.2 ± 11.5 MPa) was measured for the etch & rinse-control group. Among the bulk-fill groups, the etch & rinse technique consistently showed higher bond strengths. Bond strength of groups with shortened polymerization did not exceed 2.1 MPa. The bond strength of the self-adhesive restoration material was low before and after thermocycling (2.7 MPa/ 0.0 MPa). Groups with low bond strength values showed a high number of pre-testing-failures. CONCLUSIONS: Bulk-fill materials used in high C-factor class I-cavities showed lower bond strength during self-etch application. The same applies for a shortened polymerization regime, which cannot be recommended for high C-factor cavities. CLINICAL SIGNIFICANCE: Today, a large variety of materials and application techniques can be used when placing an adhesive restoration. Whether new instead of established procedures should be applied in high C-factor cavities has to be critically assessed, as they are a demanding scenario for adhesive restorations.

Dentin remineralization using a stimuli-responsive engineered small molecule GSK3 antagonists-functionalized adhesive.

OBJECTIVES: Tideglusib has shown great performance in terms of dentin regenerative properties. This study aims to evaluate bonding ability, of demineralized dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TG) (TG-NPs). METHODS: Dentin conditioned surfaces were infiltrated with NPs and TG-NPs. Bonded interfaces were created and stored for 24 h and then submitted to mechanical, chemical and thermal challenging. The resin-dentin interface was evaluated through a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy, and by field emission scanning electron microscopy. RESULTS: Dentin surfaces treated with TG-NPs and load cycled produced higher bond strength than the rest of the groups. Immersion of dentin specimens treated with undoped-NPs in collagenase solution attained the lowest microtensile bond strength (MTBS) values. Both porosity and nanoleakage decreased when dentin was infiltrated with TG-NPs, that revealed strong signals of xylenol orange stain at both hybrid layer and dentinal tubules. The presence of NPs, in general, inducted the presence of mineralized interfaces after mechanical loading and thermocycling. CONCLUSIONS: Nanoparticles doped with tideglusib promoted the highest dentin bonding efficacy among groups, as they facilitated the maximum bond strength values with creation of mineral deposits at the hybrid layer and dentinal walls. Tideglusib enabled scarce porosity, nanoleakage and advanced sealing among dentin groups. SIGNIFICANCE: Doping hydrophilic polymeric NPs with tideglusib, infiltrated in etched dentin represents a reproducible technique to create reparative dentin at the resin-dentin interface, by inducing therapeutic bioactivity.

Microtensile Bond Strength of Self-Etch Adhesives on Dentin Treated with Chlorhexidine.

AIM: To evaluate the microtensile bond strength of self-etching adhesive systems in dentin treated with 2% chlorhexidine digluconate (CHX). MATERIALS AND METHODS: The occlusal surfaces of 20 human molars were removed and divided into eight groups: 1A, Clearfil SE adhesive (SE) with self-etching technique (TS); 1B, SE with TS and previous application of CHX; 2A, Scotchbond Universal (SBU) adhesive with TS; 2B, SBU adhesive with TS and previous application of CHX; 1C, SE with total-etching technique (TT); 1D, SE with TT and previous application of CHX; 2C, SBU with TT; 2D SBU with TT and previous application of CHX. Composite resin (5mm) was applied on the hybridized surface. Samples were subjected to microtensile test and evaluated on Scanning Electron Microscope (SEM) and with energy-dispersive X-ray (EDX). RESULTS: Low values of bond strength were observed in groups 1A (39,77±11,56) and 2A (40,84±12,49) comparing with 1B (22,86±5,18) and 2B (27,02±5,58). TS group presented adhesive type remover fracture while TT groups presented cohesive at the top of hybrid layer. EDX revealed the presence of CHX crystals for TS, which was not found in the TT. CONCLUSION: The previous application of chlorhexidine on dentin decreased the bond strength of adhesive systems on self-etching technique.

Effectiveness of Different Application Modalities on the Bond Performance of Four Polymeric Adhesive Systems to Dentin.

One of the major goals of adhesive dentistry is to improve the interaction of the already-existing adhesives with different substrates by using different application techniques. Thus, the objective of the present in vitro study was to assess the bond performance of four adhesive systems, Prime&Bond Universal (PBU), Clearfil SE Bond (CSE), OptiBond Universal (OBU), and OptiBond FL (OBFL), to dentin using various application modes: passive application (PA), active application (AA), Compo-Vibes modified application (CVM), and Compo-Vibes application (CV). Eighty extracted human molars were allocated into four groups based on the application modalities tested. The micro-tensile bond strength as well as fracture mode were tested in accordance with ISO/TS 11.405 after 24 h and 6 months of aging. Adhesive contact angle (CA) and scanning electron microscope analysis were also performed (n = 3). Statistical tests were performed with α = 0.05. After 24 h, a significant difference with a higher bond strength value was found for PBU in the AA modality and for CSE in the CVM modality (p < 0.05). However, no significant difference was shown between the techniques used among the other adhesives (OBFL and OBU). Moreover, at 24 h, only the PA demonstrated significant differences between the tested materials (p < 0.05). After 6 months, CSE, PBU, and OBU demonstrated significant differences between the techniques (p < 0.05), with a higher bond strength for CSE in AA and CVM modalities, for PBU in AA modality, and for OBU in AA and PA modalities. No significant differences were found between the techniques used among the OBFL (p > 0.05). In addition, only the CVM technique demonstrated significant differences between the tested materials after 6 months. CV and CVM showed a decreased value after aging for CSE and PBU, respectively. However, all the modalities decreased for OBU and OBFL after aging. All the adhesives showed marked resin infiltration into dentinal tubules in AA among all the modalities tested. Both universal adhesive systems (OBU and PBU) demonstrated statistically lower CA when compared to the other systems (CSE and OBFL) (p < 0.05) when applied in the PA mode. Concerning the AA mode, only CSE and OBFL were tested. The AA demonstrated lower CA values compared to the same adhesives in PA (p < 0.05). It could be concluded that the bond strength could be influenced by both materials and application techniques. It seems that the AA technique could be recommended as a gold standard for the application of an adhesive system to dentin. Plus, the CV and CVM modalities after 6 months of aging were considered stable for PBU and CSE, respectively. Consequently, the performance of these adhesive systems might vary when applied to other modalities. Future studies are needed to test this hypothesis.

Effect of Aprotic Solvents on the Microtensile Bond Strength of Composite Core and Fiber-Reinforced Composite Posts.

This investigation evaluated the effects of aprotic solvents, i.e., tetrahydrofuran, pyridine, and morpholine, compared with hydrogen peroxide, on the surfaces of fiber-reinforced composite posts with a composite core based on the microtensile bond strength. In total, 150 FRC Postec Plus posts and 150 D.T. Light-Posts were randomly divided into three groups (non-thermocycling, 5000-cycle, and 10,000-cycle thermocycling groups). Each group was divided into five subgroups according to the post-surface treatment: C, non-treatment group; H2O2, immersed in 35% hydrogen peroxide; THF, immersed in tetrahydrofuran; PY, immersed in pyridine; and MP, immersed in morpholine. The treated specimens were placed in the bottom of a plastic cap and filled with a composite core material in preparation for the microtensile bond test. The data were evaluated using one-way ANOVA and Tukey's test (p < 0.05) as well as an independent t-test (p < 0.05). For the surface roughness, white light interferometry was used for measurement, and the mean surface roughness was analyzed via one-way ANOVA and Tukey's test (p < 0.05). The results showed that, under non-thermocycling conditions, the PY subgroup with D.T. Light-Post had the highest microtensile bond strength, followed by THF, MP, H2O2, and the control groups. For FRC Postec Plus, the PY group had the highest microtensile bond strength, followed by MP, THF, H2O2, and the control groups. Although the thermocycling conditions decreased the microtensile bond strength in all groups, the PY subgroup still had the highest value. An independent t-test revealed that even under all non-thermocycling and 5000- and 10,000-cycle thermocycling conditions, D.T. Light-Post in the PY subgroup displayed significantly higher microtensile bond strengths than FRC Postec Plus in the PY subgroup. While the surface roughness of the fiber-reinforced composite posts showed that the posts treated with pyridine possessed the highest surface roughness for each material type, In conclusion, as an aprotic solvent, pyridine generates the highest microtensile bond strength between the interfaces of composite cores and fiber-reinforced composite posts.

Effects of Short-Term Exposure of Chloramine-T Solution on the Characteristics of Light-Cured and Chemical-Cured Adhesives.

This study evaluated the effect of a 0.5% chloramine T solution on a chemical-cured universal adhesive by comparing the light-cured, one-step, self-etch adhesive for the bonding performance, mechanical properties, and resin-dentin interfacial characteristics. Caries-free human molars were randomly assigned into eight groups based on the bonding systems employed (Bond Force II, BF and Bondmer Lightless, BL), the immersion solutions used before bonding (0.5% chloramine T solution and distilled water), and the immersion durations (5 and 60 min). Microtensile bond strength (µTBS), nanoleakage evaluation, and nanoindentation tests were performed, and the surface morphology of the resin-dentin interface was examined using a focus ion beam/scanning ion microscopy system. Immersion in chloramine-T for 5 min significantly decreased the µTBS of Bondmer Lightless (from 22.62 to 12.87 MPa) compared with that in distilled water. Moreover, there was also a decreasing trend after immersing in chloramine-T for 60 min (from 19.11 to 13.93 MPa). Chloramine T was found to have no effect on the hardness, elastic modulus, or morphological characteristics of the ion-beam milled resin-dentin interfacial surfaces in the tested adhesives, suggesting that chloramine T might reduce the bond strength by interfering with the interaction and the sealing between the adhesive resin and dentin in the chemical-cured universal adhesive, albeit without affecting the mechanical properties.

Dentin Bonding Performance of Universal Adhesives in Primary Teeth In Vitro.

(1) Background: The aim of this in vitro study was to evaluate the micro-tensile bond strength (µ-TBS) of universal adhesives to primary tooth dentin after different storage periods. (2) Methods: Dentin of 100 extracted primary molars was exposed. Dentin surfaces were bonded with six universal adhesives (Adhese®Universal [AU], All-Bond Universal® [ABU], G-Premio Bond [GPB], iBond®Universal [IBU], Prime&Bond active™ [PBa], and Prime&Bond®NT as control [PBN]) and restored with a resin composite build-up (Filtek™ Z250). After 24 h, 6 months, and 12 months of water storage, specimens were cut into sticks, and µ-TBS was measured and analyzed using one-way ANOVA (p < 0.05) for normal distributions and the Mann-Whitney U-test (p < 0.05) for non-normal distribution. Pretesting failures were recorded as 0 MPa. Fracture modes were analyzed under a fluorescence microscope; interfaces were visualized with SEM/TEM. (3) Results: Compared with the reference group (PBN: 32.5/31.2 MPa after 6/12 months), two adhesives showed a significantly higher bond strength after 6 months (AU: 44.1 MPa, ABU: 40.9 MPa; p < 0.05) and one adhesive after 12 months (AU: 42.9 MPa, p < 0.05). GPB revealed significantly lower bond strengths in all storage groups (16.9/15.5/10.9 MPa after 24 h/6 months/12 months; p < 0.05). AU and IBU did not suffer pre-test-failures [PTF]. (4) Conclusions: After 12 months, PBN, IBU, AU, and GPB showed significantly lower results compared ithw initial µ-TBS, whereas AU revealed the highest µ-TBS and no PTF.

Comparative evaluation of the effect of two natural collagen cross-linkers on microtensile bond strength of self-etch adhesive system to dentin after contamination with blood and hemostatic agent: An in vitro study.

Background: Cavity preparation often causes gingival bleeding which can be controlled by hemostatic agents (HAs). These along with blood act as contaminants and hamper the bonding mechanism. Collagen cross-linkers (CCLs) are agents known to increase the bond strength (BS) to dentin. Hence, the purpose of this in vitro study was to determine the effect of two different CCLs, proanthocyanidin (grape seed extract [GSE]) and hesperidin on the microtensile BS (µTBS) of a self-etch adhesive (SEA) system to dentin which was contaminated with blood and a HA. Materials and Methods: Thirty-six extracted human molars were collected, and their occlusal surfaces were sectioned to expose the dentin. The teeth were randomly divided into four groups: Group I - Control, Group II - Contamination with blood and HA, Group III - Application of GSE after contamination, and Group IV - Application of hesperidin extract after contamination. The SEA was applied, followed by the use of a nanocomposite. Dentin-composite rods were obtained from each group, and µTBS testing was done. The fracture pattern was visually classified as an adhesive failure at the interface, cohesive failure in composite, or dentin. The scanning electron microscope (SEM) analysis was done for two samples from each group. Statistical analysis was done using the Student's unpaired "t" and ANOVA test. Results: Group II showed a statistically significant reduction in µTBS in comparison to Group I. This was overcome in Groups III and IV. Hesperidin showed marginally better results than GSE. Conclusions: The use of GSE and hesperidin increases the µTBS of composite resin to dentin postcontamination with blood and ViscoStat Clear with Single Bond Universal Adhesive.

Comparative evaluation of effect of chlorhexidine application on dentin bond strength with two different adhesives after ER, CR: YSGG phototherapy: an in vitro study.

This study aimed to assess the efficacy of phototherapy with an Er, Cr:YSGG laser on the bond strength of dentin using two different adhesive systems after chlorhexidine (CHX) application. Twenty-four non-carious human molar teeth were separated into three main groups: negative control Group A (Group A), CHX and phototherapy with an Er, Cr:YSGG laser (Group PC), and CHX with conventional diamond bur (no phototherapy) (Group C). These groups were divided into two subgroups based on adhesives: Clearfil Universal Quick Bond and Clearfil SE Bond. To evaluate the microtensile bond strength, the occlusal enamel surfaces of the teeth were removed with a low-speed, water-cooled diamond bur to expose hard dentin tissue. The teeth within Group PC were treated with Er, Cr:YSGG phototherapy. The surfaces were then disinfected with 0.2% chlorhexidine gluconate. Subgroups were applied according to the manufacturer's instructions using the adhesive systems mentioned above. Following adhesive application, the teeth were restored with composite resin. A microtensile bond strength test was performed on the test sticks obtained from the teeth using a universal test device. Data were analyzed using variance analysis (ANOVA) at a significance level of p < 0.05. Among all groups, the highest bond strength was achieved with Clearfil SE Bond with CHX + phototherapy (45.6 ± 4.2), while the lowest was achieved with Clearfil Universal Quick Bond without phototherapy (control group) (27.0 ± 6.7) (p < 0.05). Phototherapy with Er, Cr: YSGG following chlorhexidine application enhanced the bond strength of both the bond systems (p < 0.05).

The Effect of Matrix Metalloproteinase Inhibitors on the Microtensile Bond Strength of Dentin Bonding Agents in Caries Affected Dentin: A Systematic Review.

Aims and Objectives: Matrix metalloproteinases (MMPs) cause degradation of the dentinal matrix, as they act actively on collagen fibrils, leading to their deterioration and collapse. MMP inhibitors are known to be used for the pre-treatment of human dentin before bonding. Most studies on the MMP inhibitors examined the effect of MMP inhibitors on bonding to sound dentin (SD), but few examine their effect on bonding to caries affected dentin (CAD). This systematic review aims to identify and summarize studies that have applied MMP inhibitors for pre-treatment of CAD, and examine the microtensile bond strength (µTBS), bond durability, and the mode of failure. Materials and Methods: A systematic review was performed using the PubMed database according to the PRISMA guidelines. A total of 785 original articles published between 2010 and 2022 were initially retrieved. Six studies were selected based on predefined inclusion-exclusion criteria, and their outcomes were extracted and analyzed. The methodological quality assessment was performed using a combined checklist that utilizes the reporting criteria mentioned in the checklist for reporting in-vitro studies guidelines and guidelines for reporting pre-clinical in vitro studies on dental materials. Results: All six studies included here showed a definitive increase of the µTBS when MMP inhibitors were applied to the CAD. The mode of failure was found to be predominantly adhesive in nature. The deviation in the values of µTBS was approximately 2-5 MPa on immediate and delayed testing. Conclusion: MMP-inhibiting agents could be considered for the pretreatment of teeth with CAD as a part of their tooth preparation area, thereby allowing the clinician to retain CAD and bond to the CAD without endangering the vital pulp.

Effect of sodium hypochlorite on bonding performance of universal adhesives to pulp chamber dentin.

Abstract Background/purpose: The most widely utilized irrigation solution in endodontic therapy is sodium hypochlorite (NaOCl). The purpose of this study was to assess the effects of NaOCl on the bond strength of four universal adhesives and one two-step self-etch adhesive to pulp chamber dentin. Materials and methods: One hundred sixteen extracted sound human third molars were used in this study. All the teeth were divided into two groups: (1) with NaOCl treatment and (2) without NaOCl treatment. These two groups were subdivided into five bonding groups: G-Premio Bond (GP), Beautibond Xtreme (BBX), Scotchbond Universal (SBU), Clearfil Universal Bond Quick (UBQ), and Clearfil Megabond 2 (MB2). The microtensile bond strength (µTBS), the fracture mode analysis, resin-dentin interface and dentin surface were observed by SEM. Two-way ANOVA was performed to analyze the µTBS (α = 0.05). Results: The µTBS of the NaOCl group significantly decreased for GP and MB2 (P < 0.05). Significant effects of adhesive (F = 12.182, P < 0.001), and irrigation (F = 27.224, P < 0.001) on the µTBS were observed, whereas interaction between adhesive and irrigation was not significant (F = 1.761, P = 0.144). The adhesive layer with variable thickness was observed in all groups with different morphological structures. Conclusion: The effect of NaOCl treatment on the µTBS differs depending on the type of adhesives.

Effect of a novel pretreatment on the microtensile bond strength of universal adhesives with dentin.

Background: /purpose: The quality of the hybrid layer is of great importance for dentin bonding. The purpose of this study was to develop a novel copper-based pretreatment and investigate the effect of the pretreatment combined with universal adhesives on the dentin bond strength. Materials and methods: Etch-and-rinse adhesive Single Bond 2 (SB2) and two universal adhesives Prime Bond Universal (PBU) and Single Bond Universal (SBU) were selected. The dentin surfaces were pretreated with CuSO4 solution and K2HPO4 solution in turn (Cu-P pretreatment), and the adhesive was applied following the manufacturer's instructions. There were four groups of Cu-P pretreatment: HH-Cu (1.5 mol/L CuSO4 + 1.0 mol/L K2HPO4); H-Cu (0.15 mol/L CuSO4 + 0.1 mol/L K2HPO4); L-Cu (0.015 mol/L CuSO4 + 0.01 mol/L K2HPO4); and LL-Cu (0.0015 mol/L CuSO4 + 0.001 mol/L K2HPO4). The microtensile bond strength (µ-TBS) and fracture mode were determined. The dentin surface after pretreatment and the antimicrobial properties of the pretreatment agent were also evaluated. Results: The minimum inhibitory concentration and minimum bactericidal concentration of Cu-P pretreatment were 0.012 mol/L CuSO4 + 0.008 mol/L K2HPO4. Combined with SB2, the H-Cu and L-Cu groups showed a higher µ-TBS (P < 0.01), while the HH-Cu group showed a lower µ-TBS (P < 0.001), and the LL-Cu group showed a similar µ-TBS with the control group without Cu-P pretreatment. Combined with universal adhesives PBU and SBU, the H-Cu and L-Cu groups also showed significantly increased µ-TBS (P < 0.01). Conclusion: The copper-based pretreatment in combination with universal adhesives improved the dentin microtensile bond strength.

Influence of Phosphoric Acid Etching on Bond Strength for Calcium Silicate-Based Sealers.

INTRODUCTION: This study evaluated the microtensile bond strength of calcium silicate-based sealers and epoxy resin-based sealer, depending on the use of phosphoric acid (PA) etching before immediate resin restoration. METHODS: Exposed dentin surfaces of extracted human third molars were randomly assigned to 3 groups depending on sealer type (AH Plus [Dentsply DeTrey], CeraSeal [Meta Biomed Co.], and EndoSeal MTA [Maruchi]). Half of the samples were treated with PA for 30 seconds, and the other half were cleaned with water. Completely untreated specimens were used as controls. Self-etching adhesive (Clearfil SE Bond, Kuraray) was applied and composite resin (Tetric N-Ceram, Ivoclar Vivadent) was used to create build-ups. After 24 hours, the microtensile bond strength was measured (EZ Test, Shimadzu Co.). The failure mode was determined by light microscopy and scanning electron microscopy. One-way analysis of variance with the Bonferroni correction was used to analyze the data (P < .05). RESULTS: The bond strength of the water-washed dentin surfaces in the calcium silicate-based sealer groups did not differ significantly from those of the control surfaces but the PA-pretreated surfaces exhibited relatively low-bond strength. The AH Plus-treated group had lower bond strength than the control group when no PA treatment was applied, but PA treatment restored the bond strength. The adhesive failure mode was most frequently found in the AH Plus group without PA etching. CONCLUSIONS: When a water-soluble calcium silicate-based sealer is used, sufficient bond strength can be obtained by washing with water alone, with no need for PA use.