Dentin Surface Treatment Research Articles

Shear Bond Strength of Self-Adhesive Versus Conventional Flowable Composites: An In Vitro Study

Abstract Aim: As an emerging yet underexplored innovation in dentistry, self-adhesive flowable composites (SAFCs) represent a promising and enduring advancement in the dental material technology. Our study aims to evaluate the shear bond strength of two SAFCs and the bonding of conventional flowable composite (CFC) to permanent dentin. Materials and Methods: Thirty-six teeth were embedded in acrylic blocks, with the occlusal third removed to expose the underlying dentin. A cylindrical mold was positioned on the treated dentin surface and filled with the composite resin material to be evaluated. The prepared permanent dentin surfaces were randomly assigned to three groups based on the following application protocols: Group 1: Axo Uni Flow (AXIMACK, India); Group 2: Constic (DMG, Germany); and Group 3: 37% phosphoric acid etchant + Single Bond Universal + Filtek Z350 XT (3M ESPE, USA). The shear bond strength of the prepared specimens was measured by using a universal testing machine. The data were analyzed with Kruskal–Wallis one-way analysis of variance, followed by Dwass–Steel–Critchlow–Fligner pairwise comparisons. Results: Filtek Z350 XT (3M ESPE, USA) demonstrated higher shear bond strength values when compared to Constic (DMG, Germany) and Axo Uni Flow (AXIMACK, India). A significant difference was found between these materials. However, the shear bond strength of the two SAFCs tested did not differ significantly. Conclusion: The investigation’s findings suggest that the SAFCs exhibited inferior shear bond strength compared with CFCs when bonded with permanent dentin.

In situ deposition of amorphous zirconia to enhance corrosion and tribocorrosion resistance of dentin surface

With global aging and the prevalence of acidic diets, dentin exposure is becoming commonplace; thus, it is necessary to develop a treatment technology that combines resistance to wear, corrosion, and tribocorrosion. Herein, we present a promising treatment strategy that induces in situ deposition of amorphous zirconia on exposed dentin surface. The deposited amorphous zirconia bonds to dentin surface through strong chemical connection, and acts as a protective layer against acid attack and contact wear due to its acid-inertness and good mechanical properties. Consequently, the treated dentin surface exhibits encouraging corrosion and tribocorrosion performance. The deposit also provides antibacterial protection.

The effect of different conditioning agents on dentin roughness and collagen structure

ObjectivesTo assess the impact of various organic and inorganic acids on the roughness, demineralization, and collagen secondary structures of human dentin and to compare these effects with those of traditional agents, specifically phosphoric acid (PA) and ethylenediaminetetraacetic acid (EDTA). MethodsCoronal dentin discs (n = 10) were examined by optical profilometry (roughness) and ATR-FTIR before and after conditioning with 32 % PA, 3 % nitric acid (NA), 20 % citric acid (CA), 20 % phytic acid (IP6) or 17 % EDTA. Spectra data were processed to quantify dentin demineralization (DM%) and percentage area of amide I curve-fitted components of β-turns, 310-helix, α-helix, random coils, β-sheets, and collagen maturation index. Statistical analysis was performed by one-way ANOVA or Kruskal-Wallis for DM% and roughness parameters, and paired t-test/Wilcoxon test for amide I components at significance level set at α = 0.05. ResultsAll treatments resulted in increased roughness parameters, with the most significant changes occurring primarily with PA, while EDTA exhibited the least changes. DM% was NA>PA>IP6>CA>EDTA in a descending order. Regarding amide I components, NA demonstrated a significant reduction in β-turns, 310-helices, and α-helices and it increased β-sheets and random coils. PA resulted in reduction in β-turns and α-helices while it increased β-sheets. CA and EDTA did not cause significant changes. The collagen maturation index significantly increased only after IP6 treatment. ConclusionsThe effect on dentin roughness parameters, demineralization, and collagen secondary structures varied based on the type of dentin surface treatment. Clinical significanceUnderstanding the impact of acids on the intrinsic properties of dentin is clinically essential for gaining insights into how these effects influence adhesion to dentin, the long-term stability of resin-based restorations, and the success of remineralization therapies.

Effects of different concentrations of bromelain and papain enzymes on shear bond strength of composite resin to deep dentin using an etch-and-rinse adhesive system.

The dentin substrate can be modified by proteolytic agents, which may affect the bonding strength of adhesive systems to the treated dentin surface. Papain, a cysteine protease enzyme with antibacterial and anti-inflammatory properties, can be used for deproteinization of dentin. An alternative deproteinizing enzyme is bromelain. This study aimed to evaluate the impact of deproteinization on the shear bond strength (SBS) of composite resin to deep dentin using different concentrations of bromelain and papain. Sixty upper premolars were extracted and randomly divided into 5 groups (n = 12 per group). In all groups, the dentin surface was etched with 37% phosphoric acid. Group 1 did not receive any enzyme treatment, group 2 was treated with a 10% papain solution, group 3 was treated with a 15% papain solution, group 4 was treated with a 6% bromelain solution, and group 5 was treated with a 10% bromelain solution. After applying an etch-and-rinse adhesive system, the specimens were restored with composite resin and the SBS was measured. Statistically significant differences were found between groups 2 and 3 (10% papain and 15% papain, p = 0.004), groups 2 and 4 (10% papain and 6% bromelain, p = 0.017), groups 4 and 5 (6% bromelain and 10% bromelain, p = 0.021), and groups 3 and 5 (15% papain and 10% bromelain, p = 0.005). Deproteinization with papain and bromelain at different concentrations after acid etching did not affect the SBS of composite resin to deep dentin when using an etch-and-rinse adhesive system. However, the group deproteinized with 15% papain demonstrated a higher SBS than the group deproteinized with 10% papain, and the group deproteinized with 6% bromelain showed a higher SBS compared to the group deproteinized with 10% bromelain.

Particle abrasion as a pre-bonding dentin surface treatment: A scoping review.

This scoping review aims to assess the influence of air abrasion with aluminum oxide and bioactive glass on dentin bond strength. An electronic search was conducted in three databases (PubMed, Cochrane Library, and Embase), on March 3rd, 2023, with previously identified MeSH Terms. A total of 1023 records were screened. Exclusion criteria include primary teeth, air abrasion of a substrate other than sound dentin, use of particles apart from aluminum oxide or bioactive glass, and studies in which bond strength was not assessed. Out of the 1023 records, title and abstract screening resulted in the exclusion of 895 and 67 studies, respectively, while full-text analysis excluded another 25 articles. In addition, 5 records were not included, as full texts could not be obtained after requesting the authors. Two cross-references were added. Thus, 33 studies were included in this review. It is important to emphasize the absence of standardization of air abrasion parameters. According to 63.6% of the studies, air abrasion does not influence dentin bond strength. Moreover, 30.3% suggest improving bonding performance, and 6.1% advocate a decrease. Air abrasion with aluminum oxide does not enhance or impair dentin bond strength. The available data on bioactive glass are limited, which hinders conclusive insights. Dentin air abrasion is a widely applied technique nowadays, with numerous clinical applications. Despite the widespread adoption of this procedure, its potential impact on bonding performance requires a thorough analysis of the existing literature.

Performance of self-etching adhesives on caries-affected primary dentin treated with glutaraldehyde or silver diamine fluoride

Objectivesto evaluate the quality and stability of adhesive interfaces established by self-etching adhesives on caries-affected primary dentin (CAD) treated with glutaraldehyde (GA) or silver diamine fluoride (SDF). Methods42 primary molars were exposed to a microbiological caries-inducing protocol and divided into 6 groups according to the adhesive system (Clearfil SE - CL or FL Bond II - FL) and pretreatment (water, GA or SDF) applied on CAD. One tooth from each group was analyzed for surface modification using infrared spectroscopy. Crowns were restored with resin composite (n = 36) and cut into beams and slices. The beams were subjected to microtensile testing, Raman spectroscopy and SEM after 24 h and 6 months of storage. The slices were analyzed using Micro-Raman spectroscopy to determine the diffusion zone thickness (DZ) in each period. Data were analyzed by ANOVA and Tukey or Kruskal-Wallis and Dunn tests (α = 0.05%). ResultsSDF reduced the immediate bond strength for both adhesives. The control groups showed a decrease in BS after 6 months in artificial saliva. GA increased immediate DZ for FL, while SDF had the opposite effect on CL. GA decreased the DZ for FL at 6 months. There was a predominance of adhesive failures with areas of cohesive dentin fractures within control groups. SignificanceModifications caused by dentin surface treatments may directly affect the performance of adhesive systems and the quality and stability of adhesive restorations.

Effect of Dentin and Zirconia Surface Treatments with Laser Irradiation Versus Sandblasting on the Bonding Ability of Zirconia.

Objective: This study aimed to investigate the effects of laser irradiation applied to zirconia and tooth surfaces on shear bond strength (SBS) compared with acid etching and sandblasting. Background: The effect of laser irradiation on the bond strength between zirconia and adhesives is a controversial issue for dentin surface treatments. In addition, the effects of different combinations of surface treatments to increase adhesion on both the zirconia and dentin surfaces remain unclear. Materials and methods: A total of 90 tooth samples were assigned into groups according to various pretreatments: control group was left untreated, acid etching, and Erbium, Chromium:Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser irradiation group (15 Hz, 2 W). In addition, the zirconia specimens were separated into three groups (n = 10) according to the different surface treatments performed: sandblasting (120 μm Al2O3), Er,Cr:YSGG laser (15 Hz, 2 W), and as untreated surface. The zirconia samples were cemented to the dentin surface using dual-cure resin cement and subjected to an SBS test at a speed of 0.5 mm/min under a universal testing machine until fractures occurred in the bonding surface. Results: The highest SBS values were observed in Group tooth acid (TA)-zirconia Er,Cr:YSGG laser (ZL), followed by Group tooth Er,Cr:YSGG laser (TL)-zirconia sandblasting (ZS) and Group TA-zirconia control (ZC). The lowest SBS values were found in Group TA-ZS. Significant intergroup difference was noted between Group TA-ZL, Group tooth control (TC)-ZC, Group TL-ZS, and Group TC-ZC. However, no significant difference was noted between Group TA-ZL, Group TL-ZS, and Group TA-ZC. Conclusions: Acid etching and laser treatments applied to the dentin and zirconia surfaces were found to be effective techniques for improving the zirconia-dentin bond, respectively. Clinical Trial Registration number: 33216249-604.01.02-E.24308.

Bonding performance of glass ionomer cement to carious dentin treated with different surface treatment protocols using silver diamine fluoride

This study investigated the influence of silver diamine fluoride (SDF) on the shear bond strength (SBS) to artificial carious dentin and GIC restorations with various SDF application protocols. Artificial caries were prepared on human dentin discs using bacteria model. These samples were randomly allocated to five groups (n = 10/group) according to the following treatment: (1) control group (CD): no treatment (2) CSR: dentin conditioner, SDF, and rinsing (3) CS: dentin conditioner and SDF (4) SRC: SDF, rinsing and dentin conditioner, and (5) SC: SDF and dentin conditioner. The treated-dentin surface was bonded with GIC and subjected to SBS test. Mean SBS was analyzed using one-way ANOVA. Surface morphology and elemental contents after surface treatment were examined (n = 3/group) by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX). There was no significant difference in the mean SBS among CD (2.45 ± 0.99 MPa), CSR (1.76 ± 0.65 MPa), and SRC (2.64 ± 0.95 MPa). Meanwhile, the mean SBS of CS (0.35 ± 0.21 MPa) was significantly lower than the control and SRC group. SEM/EDX demonstrated deeper silver penetration in CSR and CS groups when compared to SRC and SC groups. SDF-modified GIC restorations resulted in significantly lower bond strength in CS and SC groups. The findings suggested treating the carious dentin surface with CSR and SRC protocol. SDF-treated carious dentin should be rinsed off prior to restore with GIC.

Effect of S. mutans biofilm on the hybrid ceramic-resin cement bond strength assessed by different methods

Aim: The purpose of this study was to investigate the biofilm effect on the hybrid ceramic-resin cement bond strength (BS) by comparing two methods. Methods: Teeth were distributed into groups (n=5), according to the resin cement (Maxcem Elite-(MC) or NX3 Nexus-(NX)) and degradation method (24h or 7 days in distilled water; 7 or 30 days incubated with biofilm and 30 days in sterile media). Treated surfaces of Vita Enamic blocks (5x6x7mm) were luted to treated or no treated dentin surfaces and light-cured. After 24h, beams were obtained (1x1x10mm) and stored accordingly. The flexural bond strength (FBS) was assessed by four-point bending test. Additional beams were obtained from new teeth (n=5), stored for 24h or 7 days in distilled water, and submitted to a microtensile bond strength (μTBS) assay. Failure modes were determined by scanning electron microscopy (100X). The flexure strength of the cements (n=10) was assessed by a four-point bending test. Data were analyzed by 1 and 2-ways ANOVA, and Tukey’s test (α=0.05). Results: There was no significant difference between the degradation methods for the FBS groups. For the μTBS, the significant difference was as follows: NX 7days > NX 24h > MC 7days = MC 24h. Failure mode was mainly adhesive and mixed, but with an increase of cohesive within cement and pre-failures for the MC groups assessed by μTBS. NX had better performance than MC, regardless of the method. Conclusions: The biofilm had no effect on the materials BS and FBS test was a useful method to evaluate BS of materials with poor performance.

Effect of Dentin Surface Pretreatment With Chitosan Nanoparticles on Immediate and Prolonged Shear Bond Strength of Resin Composite: An in Vitro Study

Introduction: The objective of this study was to evaluate the impact of chitosan nanoparticles’ pretreatment of dentin surface on the macro shear bond strength of resin composite, both immediately and over an extended period. Methods: Thirty caries-free, unrestored human premolars were randomly assigned to six study groups. The dentin surface of the intervention groups underwent pretreatment with 0.2% chitosan and 0.05% NaF solutions for 1 minute. A standard etch-and-rinse adhesive procedure was performed for all the study groups. After 24 hours, half of the specimens underwent a macro shear bond strength test at a crosshead speed of 1 mm/min, whereas the other specimens underwent the same procedure after 300 thermal cycles between 5 and 55°C with a 30-second dwell time in the thermocycling device. Results: The study found that the type of dentin surface treatment agents did not significantly affect the shear bond strength (P = 0.52). However, there were statistically significant differences between immediate and prolonged shear bond strength in the chitosan (P < 0.01) and the control groups (P = 0.005). On the other hand, there were no significant differences between the immediate and prolonged shear bond strength in the NaF group (P = 0.997). Conclusion: Dentin pretreatment with 0.2% chitosan solution did not significantly affect the shear bond strength of the etch-and-rinse adhesive system. Pretreatment with NaF maintained the shear bond strength of the adhesive to dentin after 300 thermal cycles.

A SEM Evaluation of the Permeability of Different Desensitizing Methods on Occlusion of Dentinal Tubules: An In-vitro Study.

The purpose of the current research was to assess the permeability of three various desensitizing techniques on dentinal tubule occlusion using a scanning electron microscope (SEM). For this research, 100 human sound premolar teeth that were extracted for orthodontic purposes were gathered. With the aid of a water-cooled diamond saw, the teeth were divided in a mesiodistal (vertically) orientation. A sectioned sample (5 mm long by 5 mm wide by 3.5 mm deep), including the cervical region, was taken from each buccal side. To fully open the dentinal tubules, these samples were then kept in 17% ethylenediaminetetraacetic acid (EDTA) for 40 minutes. The samples were divided into four groups (n = 25), each receiving the following dentin surface treatments: Group I: Control, Group II: Samples received NaF 5% varnish treatment, Group III: Samples received diode laser treatment, and Group IV: Samples received CPP-ACP treatment. An SEM was used to inspect each specimen at a magnification of about × 3000 and photomicrographs was assessed. The maximum occlusion of dentinal tubules was found in samples were treated with Diode laser (2.96 ± 0.14) followed by samples treated with NaF 5% varnish (3.38 ± 0.10), samples were treated with CPP-ACP (3.42 ± 0.06) and control group (4.26 ± 0.19). There was a statistically significant difference found between the groups. In conclusion, all three desensitizing methods used in the present study were successful in the occlusion of dentin tubules. But the application of the Diode laser was effective in the reduction of dentin permeability compared to NaF 5% varnish and CPP-ACP. Dentin hypersensitivity (DH) is characterized by a brief period of intense discomfort. One approach to managing DH is to obstruct dentin tubules in order to decrease dentin permeability. There are many substances that can reduce hypersensitivity, but the finest commercially available substance for treating the condition by occluding the tubes should be acknowledged.

Effect of Silica-Modified Aluminum Oxide Abrasion on Adhesion to Dentin, Using Total-Etch and Self-Etch Systems

This study compared the shear bond strength (SBS) and micromorphology of composite resin to human dentin after pre-treatment with silica-modified aluminum oxide air abrasion. Forty-six molar teeth were treated with either Scotchbond Multi-Purpose (SCMP) or Clearfil SE Bond (CLSE) adhesive. Buccal surfaces were pre-treated with the CoJet air abrasion system (SB), and lingual surfaces were controls. The adhesion of light-cured resin composite to the treated dentin surface was evaluated with SBS. After debonding, substrate surfaces were examined with an optical microscope for failure analysis. In addition, 15 molar teeth were sectioned and randomly assigned to one of five groups, according to the dentin surface pre-treatment and adhesive type, and examined with high-vacuum scanning electron microscopy/energy dispersive X-rays (SEM/EDS). The type of adhesive had a significant effect on SBS (p = 0.000); CLSE had the highest values. SB did not affect SBS (p = 0.090). SEM/EDS revealed residual aluminum and/or silicon on all dentin surfaces after SB, except for the control. Treatment with 32% phosphoric acid in the SCMP adhesive decreased the amounts of aluminum and silicon compared to SB dentin only, whereas CLSE resulted in similar quantities of aluminum and silicon as air-abraded dentin. The results of this study indicate that CLSE might have a higher bond strength to dentin than SCMP. Pre-treatment with SB does not appear to affect bonding strength.

Evaluation of the remineralizing capacity of silver diamine fluoride on demineralized dentin under pH-cycling conditions.

(1) to determine the effects of the silver diamine fluoride (SDF) and sodium fluoride (NaF) in demineralized dentin exposed to an acid challenge by pH-cycling, (2) to evaluate the remineralizing capacity of SDF/NaF products based on the physicochemical and mechanical properties of the treated dentin surfaces. In total, 57 human molars were evaluated in different stages of the experimental period: sound dentin - negative control (Stage 1), demineralized dentin - positive control (Stage 2), and dentin treated with SDF/NaF products + pH-c (Stage 3). Several commercial products were used for the SDF treatment: Saforide, RivaStar, and Cariestop. The mineral composition and crystalline and morphological characteristics of the dentin samples from each experimental stage were evaluated by infrared spectroscopy (ATR-FTIR), X-ray diffraction, and electron microscopy (SEM-EDX) analytical techniques. Moreover, the mechanical response of the samples was analyzed by means of the three-point bending test. Statistics were estimated for ATR-FTIR variables by Wilcoxon test, while the mechanical data analyses were performed using Kruskal-Wallis and Mann Whitney U tests. Regarding the chemical composition, we observed a higher mineral/organic content in the SDF/NaF treated dentin + pH-c groups (Stage 3) than in the positive control groups (Saforide p=0.03; Cariestop p=0.008; RivaStar p=0.013; NaF p=0.04). The XRD results showed that the crystallite size of hydroxyapatite increased in the SDF/NaF treated dentin + pH-c groups (between +63% in RivaStar to +108% in Saforide), regarding the positive control. SEM images showed that after application of the SDF/NaF products a crystalline precipitate formed on the dentin surface and partially filled the dentin tubules. The flexural strength (MPa) values were higher in the dentin treated with SDF/NaF + pH-c (Stage 3) compared to the positive control groups (Saforide p=0.002; Cariestop p=0.04; RivaStar p=0.04; NaF p=0.02). The application of SDF/NaF affected the physicochemical and mechanical properties of demineralized dentin. According to the results, the use of SFD/NaF had a remineralizing effect on the dentin surface even under acid challenge.

The Effect of Dentin Contamination by Topical Anesthetics on Micro-Shear Bond Strength: An In Vitro Experiment.

Topical anesthetics are commonly used to minimize pain and anxiety during dental procedures. Research is scarce on the influence of topical anesthetics on bond strength. Thus, this research evaluated the effect of dentin contamination by topical anesthetic solution and gel on the micro-shear bond strengths of etch-and-rinse and self-etch bonding systems. Ninety transversally hemi-sectioned dentin discs were prepared and randomly assigned to three groups: no contamination (control group), contamination with topical anesthetic solution (Xylonor spray, Septodont), and contamination with topical anesthetic gel (Xylonor gel, Septodont). Each contamination group was subdivided into two subgroups (n = 15) based on whether the adhesive system was etch-and-rinse (Optibond Solo Plus, Kerr) or self-etch (Optibond XTR, Kerr). Tygon tubes with resin composite (Filtek Z350 XT, 3M ESPE) were placed on each surface and light cured. After 24 h, a universal testing machine was used to measure micro-shear bond strength (MPa). Furthermore, nine additional specimens of non-contaminated and contaminated dentin were prepared and scanned by a scanning electron microscope. The data of micro-shear bond strength were analyzed using two-way ANOVA, and narrative analysis was used to qualitatively interpret visual data of the micro-morphology of dentin from the scanning electron microscope. No significant differences in micro-shear bond strength among different contamination groups and adhesive systems were found (p > 0.05). The results are supported by micro-morphology of the treated dentin surfaces and modes of failure, as the micro-morphology was similar among contamination and control groups. There was no significant impact of topical anesthetic forms and dentin bonding systems on the micro-shear bond strength, which was supported by the micro-morphology from a scanning electron microscope.

Effect of adhesive strategy on resin cement bonding to dentin.

The cement bonding strategy and the polymerization mode can influence the prognosis of indirect restorations. The microtensile bond strength (μTBS) and dentin endogenous enzymatic activity of a dual-cure resin cement (PV5) used in combination with two dentin surface conditioners (accelerator-enhancer primer, TP or universal adhesive, UA) were evaluated. PV5 was used to lute composite overlays after dentin treatment with TP or UA. The resin cement was self-cured, SC (1 h at 37 °C) or dual-cured, DC (20 s light-cure followed by 15 min self-cure at 37°C). The μTBS test, fractographic analysis, and the in situ zymography evaluations were performed after 24 h (T0 ) or 1 yr (T12 ) of artificial storage. Data were statistically analyzed (α=0.05). TP/DC obtained the highest adhesive strengths (45 ± 9 and 36.6 ± 8), while UA/SC (17 ± 8 and 11 ± 4) the lowest, both at T0 and T12 , respectively. DC resulted in superior bonding values than the SC, independent of the dentin surface treatment (p < 0.05). The type of adhesive, curing mode and aging influenced the gelatinolytic activity (p < 0.05). The dual-cure resin cement used in combination with its accelerator-enhancer primer showed superior bonding performances with respect to universal adhesive. Dual-curing the resin cement was determinant to enhance bonding capability over time, independent of the adhesive strategy. Clinicians must be aware to faithfully follow manufacturer's recommendation regarding the adhesive strategy suggested with the resin cement used.

Remineralization of Artificially Demineralized Human Enamel and Dentin Samples by Zinc-Carbonate Hydroxyapatite Nanocrystals.

(1) Background: Decalcified enamel and dentin surfaces can be regenerated with non-fluoride-containing biomimetic systems. This study aimed to investigate the effect of a zinc carbonate-hydroxyapatite-containing dentifrice on artificially demineralized enamel and dentin surfaces. (2) Methods: Human enamel and dentin discs were prepared and subjected to surface demineralization with 30% orthophosphoric acid for 60 s. Subsequently, in the test group (n = 20), the discs were treated three times a day for 3 min with a zinc carbonate-hydroxyapatite-containing toothpaste (biorepair®). Afterwards, all samples were gently rinsed with PBS (5 s) and stored in artificial saliva until next use. Samples from the control group (n = 20) received no dentifrice-treatment and were stored in artificial saliva, exclusively. After 15 days of daily treatment, specimens were subjected to Raman spectroscopy, energy-dispersive X-ray micro-analysis (EDX), white-light interferometry, and profilometry. (3) Results: Raman spectroscopy and white-light interferometry revealed no significant differences compared to the untreated controls. EDX analysis showed calcium phosphate and silicon dioxide precipitations on treated dentin samples. In addition, treated dentin surfaces showed significant reduced roughness values. (4) Conclusions: Treatment with biorepair® did not affect enamel surfaces as proposed. Minor mineral precipitation and a reduction in surface roughness were detected among dentin surfaces only.

Etch-mineralizing treatment to improve dentin bonding

Objectives This study aimed to investigate the effect of etch-mineralizing solution as a dentin treatment agent on dentin bonding.Methods This study designed four kinds of etch-mineralizing solutions (EMs) by adding sodium fluoride in 35% phosphoric acid aqueous solution with four different concentrations (5, 10, 20, and 30 mg/ml), and named F1, F2, F3 and F4, respectively. 35% phosphoric acid gel treatment was the control group. SEM, EDS, FTIR and microhardness tests were performed on the treated dentin. Shear bond strength was measured before and after aging. Nanoleakage was also evaluated. Fracture mode was researched after SBS testing. The antibacterial properties of treated dentin were also investigated through live/dead staining of biofilms.Results The smear layer was removed and mineralization substances were observed on the dentin surface and tubule, and no obvious collagen fibers were observed compared with the control group. FTIR spectrums showed that the ratios of phosphate/collagen on EMs treated dentin surfaces were significantly increased (P < 0.05). F2 group had the highest bonding strength (32.14 ± 7.33 MPa) and microhardness (66.08 ± 10.58), while the control group had the lowest bonding strength (21.81 ± 4.03 MPa) and microhardness (42.34 ± 7.08) (p < 0.05), and excellent bonding strength caused more cohesive fracture. Experimental groups showed less nanoleakage than group C (P < 0.05). Moreover, experimental groups had better antiaging performance and antibacterial properties than the control group (p < 0.05).Conclusion EMs treatment not only improved dentin bonding and antibacterial ability, but also remineralized dentin with autologous mineral elements.Clinical significance The treatment provides a novel therapeutic strategy for obtaining ideal dentin bonding strength and prolonging the longevity of the restoration.

Effect of Er:YAG, Co2 lasers, papain, and bromelain enzymes dentin treatment on shear bond strength of composite resin.

Effective bond strength of composite resin restoration leads to its durability, so evaluation of dentin surface treatment with enzymes and laser for higher bond strength is an important factor. Sixty human molar teeth were cut at a depth of 2 mm of occlusal part and divided into sixgroups (n = 10). G1: etched with 37% phosphoric, G2 and G3: 10% papain or bromelain enzymes were used on the dentinal surface, G4: 10% papain and bromelain enzyme mixture were used for. Then, the specimens were washed with distilled water. In G5 and G6: Er:YAG or Co2 lasers were used on the dentin surface. An adhesive system was applied and then nanohybrid composite was placed in teflon mold and lightcured. Samples were subjected to a shear bond strength (SBS) testby universal testing machines. Statistical analysis was performed, using one-way analysis of varianceand Tukey HSD tests (p < .05). The mean SBS in G1 was significantly higher in comparison with the other groups (p < .0001). On the other hand, a comparison of mean SBS between groups 2, 3, 4, and 5 shows no significant differences (p = .221). The mean SBS in group 6 (Co2 laser) was significantly lower in comparison with the other groups (p < .0001). Results showed that SBS of composite resin to dentin was not significantly affected, using either bromelain or papain 10% enzymes or erbium laser. Co2 laser had a negative effect on dentin and decreased the SBS. Phosphoric acid has the best result.

Er,Cr:YSGG Laser Surface Modification Effect on Dentin Bonding to Zirconia: An In Vitro Study.

Objective: This study investigated the effect of dentin surface treatment with the erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser on the bond strength of zirconia to dentin. Background data: Although it is well-known that resin cement (RC) provides adequate bond strength of zirconia restorations to the tooth structure, many clinicians were not convinced in bonding reliability to zirconia materials. So, they preferred cementing their crowns with glass-ionomer cement (GIC). Pretreating the dentin surface is recommended to improve the adhesion of crowns cemented with GIC or RC. Recently, the Er,Cr:YSGG laser has been widely used for a cavity preparation, conditioning the tooth structure. However, there is not enough research on the bond strength of zirconia crowns cemented on a Er,Cr:YSGG laser-treated dentin. Methods: Forty-eight molars were cut horizontally at the crest of curvature. The flat dentin surface of 24 molars was left untreated, whereas the dentin surface of the other half was treated using an Er,Cr:YSGG laser 2.78 μm (4.5 W, 8.18 J/cm2, 90 mJ, 60 μs, 50 Hz, 60% air and 80% water). In addition, 48 plates of zirconia were prepared to be cemented with GIC or RC on the dentin surface. So, the molars were divided into four groups as follows: GIC+untreated dentin; GIC+treated dentin; RC+untreated dentin; and RC+treated dentin. All the specimens were subjected to shear bond strength test. The mode of failure was determined and additional samples were prepared to evaluate the cement-dentin interface using a scanning electron microscope. Data were analyzed with two-way analysis of variance accompanied by univariate analyses. Results: The bond strength of zirconia cemented with GIC or bonded with RC significantly increased on a Er,Cr:YSGG laser-treated dentin surface (p < 0.05). Conclusions: Dentin preconditioning with an Er,Cr:YSGG laser significantly improved the bond strength of zirconia plates to dentin as compared with untreated dentin.

EFFECT OF DIFFERENT SALIVA DECONTAMINATION PROCEDURES ON THE SHEAR BOND STRENGTH OF A UNIVERSAL EIGHTH GENERATION ADHESIVE SYSTEM TO DENTIN AFTER POLYMERIZATION - AN IN VITRO STUDY

Aim: To evaluate and compare the effect of saliva decontamination procedure on the shear bond strength of a Universal eighth generation adhesive system to dentin after polymerization. Materials &amp; Method: Forty extracted non-carious premolars were mounted on a acrylic block and their occlusal surfaces were grounded flat to exposed the middle depth dentin. The teeth were then randomly divided into five Groups: Group A(control), Group B(Bonding, Saliva, Air-dried), Group C(Bonding, Saliva, Air-dried, Rinse), Group D(Bonding, Saliva, Air-dried, Re-bonding) &amp; Group E (Bonding, Saliva, Air-dried, Rinse, Re-bonding). A teflon tube of 2x3 mm dimension was used to pack composite on the treated dentin surface and light cured for 40s. Shear Bond strength was then measured using instron testing machine at a crosshead speed of 1mm/min. Data were statistically analysed using ONE WAY-ANOVA and TUKEYS test. Result: It was observed that, the highest mean shear bond strength was found in Group D(Bonding, Saliva, Air-dried, Re-bonding) &amp; Group E(Bonding, Saliva, Air-dried, Rinse, Re-bonding) with a mean value of 23.87 each. The least mean value was seen in Group C(Bonding, Saliva, Air-dried, Rinse), 13.25. When an intergroup comparision was made, statistically significant difference was seen between the various groups except Group A(control)-Group D(Bonding, Saliva, Air-dried, Re-bonding)-Group E(Bonding, Saliva, Air-dried, Rinse, Re-bonding) and Group B(Bonding, Saliva, Air-dried)-Group C(Bonding, Saliva, Air-dried, Rinse). Conclusion: Salivary contamination significantly decreases the bond strength of the adhesive to dentin after polymerization. Rinsing and Air-drying of the cured contaminated dentin surface was not sufficient to restore the shear bond strength. However reapplication of adhesive system after rinsing and air-drying of the cured contaminated dentin surface fully restored the bond strength.