Effect of the resin system on dentin bond strength

The tensile bond strength for four commercial dentin bonding agents (Gluma Dentin Bond, Dentin Adhesive, Dentin Adhesit and Scotchbond) and two experimental dentin bonding agents, which contains different resin system respectively was tested. The range of bond strength to human dentin for the four commercial products is from 2.6 MPa to 6.2 MPa, the Gluma got the best value among them and for the two experimental dentin bonding agents the value is 16.6 MPa and 12.8 MPa. After thermal cycle (5 degrees C/55 degrees C, 30 sec 1000 periods) the bond strength for all materials fell down obviously, but experimental dentin bonding agent No. 2 kept its value in 9.3 MPa.     

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牙齿粘接涉及釉质和牙本质。因牙本质的组成和结构具有特殊性，其粘接更困难些。本文介绍了目前粘接剂粘接釉质和牙本质的基本原理及应用技术。     

Tensile Bond Strengths of Fourth- and Fifth-Generation Dentin Adhesives with Packable Resin Composites

Purpose: Placement of packable composites would be simplified if a single-bottle dentin bonding agent, rather than the more complex, multiple-bottle dentin bonding agents, involving multiple steps, could be used successfully with adequate bond strength. This study was designed to compare the tensile bond strengths to extracted human dentin of four single-bottle (fifth-generation) and four multiple-bottle (fourth-generation) dentin bonding agents with four packable composites.
Materials and Methods: Packable composites (P60, 3M Dental Products Division; ALERT, Jeneric-Pentron; Pyramid Dentin, Bisco; and Clearfil AP-X, Kuraray America) were tested for in vitro tensile bond strength to human dentin with their single-bottle and their multiple-bottle dentin bonding agents. Bond strengths were measured using a truncated cone tensile test, with a bonding diameter of 3 mm, after storage of specimens in water at 37°C and 100% relative humidity for 24 hours, and using a testing machine at a crosshead speed of 0.5 mm per minute.
Results : Means and standard deviations (n = 10) of tensile bond strengths (MPa) for the single-bottle system were P60, 21.3 MPa (6.7); ALERT, 26.6 MPa (4.2); Pyramid Dentin, 14.8 MPa (4.4); and Clearfil AP-X, 18.6 MPa ( 3.7 ). For the multiple-bottle system they were P60, 20.0 MPa (8.6); ALERT, 20.6 MPa (6.2); Pyramid Dentin, 16.0 MPa (3.4); and Clearfil AP-X, 17.8 MPa (6.0). Two-way analysis of variance showed significant differences among composites but no significant differences between single-bottle and multiple-bottle bonding agents. The Tukey-Kramer interval ( p < .05) for comparisons of bond strengths among composites was 4.8 MPa.
Conclusions: For single-bottle agents, bond strengths were ranked as ALFLRT > P60, P60 = Clearfil, P60 > Pyramid, and Clearfil = Pyramid. For multiple-bottle agents, there were no significant differences in bond strengths among the composites.     

Determination of elastic modulus of the components at dentin-resin interface using the ultrasonic device

The purpose of this study was to determine the elastic moduli of the components at resin-dentin interface with the use of an ultrasonic device. Dentin plates were obtained from freshly extracted bovine incisors with a shape in rectangular form. Resin composites and bonding agents were polymerized and trimmed in the same shape as the dentin specimens. The ultrasonic equipment employed in this study was comprised of a Pulser-Receiver, transducers, and an oscilloscope. Each elastic modulus was determined by measuring the longitudinal and shear wave sound velocities. The mean elastic modulus of mineralized dentin was 17.4 GPa, while that of demineralized dentin was 1.4 GPa. When the demineralized dentin was immersed in bonding agents, the elastic modulus changed to 3.7-4.7 GPa, and these values were significantly higher than those of demineralized dentin. A gradient in elastic modulus was detected as the analysis shifted from the dentin side to the resin composite.     

牙本质表面不同处理方法对粘接剂与牙本质间剪切强度的影响

目的研究氧化锌丁香酚黏固剂和Gluma脱敏剂对牙本质与磷酸锌黏固剂、玻璃离子黏固剂和Super- BondC&B树脂粘接剂间剪切强度的影响,为临床上牙体制备后应用不同的保护方法及选用不同类型的粘接剂提供理论依据。方法90颗前磨牙在流水冲洗下去除颊面釉质暴露浅层牙本质。依次用粒度为320、400、600目的水砂纸磨平牙本质粘接面。牙根用自凝树脂包埋,牙冠暴露。包埋好的90颗牙齿随机分为3个大组,分别为：A组为对照组,牙本质表面不作任何处理;B组牙本质表面用氧化锌丁香酚黏固剂均匀涂抹一薄层;C组用Gluma脱敏剂均匀涂抹一薄层。测试两种处理剂处理牙本质表面后,3种粘接剂与牙本质间剪切强度的大小,进行统计分析及扫描电镜观察。结果应用两种处理剂后磷酸锌黏固剂与牙本质间剪切强度明显下降（P<0.05）,C1组下降更明显;玻璃离子黏固剂和Super- Bond C&B树脂粘接剂与牙本质间剪切强度没有明显变化。结论两种处理剂均对磷酸锌黏固剂与牙本质间粘接强度有不利影响;对玻璃离子黏固剂和Super- Bond C&B树脂粘接剂与牙本质间粘接强度无不利影响。     

Effect of dentin on the antibacterial activity of dentin bonding agents

Dentin bonding agents with antibacterial effects may inhibit secondary caries formation and pulp inflammation by eliminating residual bacteria in and on dentin. Therefore, the antibacterial effects of Prime & Bond NT (PB), Prime & Bond NT without fluoride (PBNF), Gluma Comfort Bond (GL), ABF, Xeno CF II (XE), 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEG-DMA), and 0.2% chlorhexidine were tested against Streptococcus mutans, S. sobrinus, and Lactobacillus acidophilus using the agar-diffusion method with and without bovine-dentin disks (200 microm and 500 microm thickness) placed between the bacteria and the test substances. Without dentin, ABF Primer showed growth inhibition for all bacterial strains. XE inhibited S. mutans and S. sobrinus, and PB S. sobrinus. ABF Bonding inhibited L. acidophilus. PBNF, HEMA, and TEGDMA did not have any antibacterial effects. Dentin disks of 500 microm thickness reduced the inhibitory effect of chlorhexidine to 23% to 54% compared with direct application. ABF Primer (nonpolymerized) produced inhibition zones against all tester strains regardless of dentin disks interposed or not. XE (against S. mutans and S. sobrinus) and PB (against S. sobrinus) did not produce any inhibition zones on 200 microm thick dentin. After polymerization, the ABF system did not inhibit bacterial growth on 200 microm thick dentin disks. A dentin barrier reduces significantly the antibacterial activity of chlorhexidine and dentin bonding agents.     

Water uptake of bonding systems applied on root dentin surfaces: a SEM and confocal microscopic study.

OBJECTIVES: Dentin adhesives have been proposed as desensitizing agents to seal exposed root dentin surfaces. Simplified 'one-step' dentin adhesives are highly permeable to water. The authors hypothesized that a lactic acid challenge may increase permeability of simplified adhesives and may induce fast degradation of bonding. This phenomenon adversely affects their durability as long term desensitizing agents. The aim of this in vitro study was to evaluate the ability of four dentin adhesives to seal root dentin surfaces that were exposed to water and lactic acid challenges. METHODS: Four commercially-available dentin adhesives were applied with a small sponge to the root dentin of extracted human molars as de-sensitizing agents. Impression replicas of the adhesive-covered root dentin were fabricated after water immersion, as a control, and after lactic acid challenge. The replicas were examined with SEM for quantitative comparison of fluid droplet formation on the surfaces. The bonded specimens were also examined using reflected light confocal microscopy. RESULTS: Replicas of water droplets were observed on the adhesive surfaces, by SEM which corresponded with direct confocal observation of blisters and voids from the surface of the bonded specimens. There were significantly more water droplets from samples that were subjected to lactic acid challenge than water only immersion. SIGNIFICANCE: Although the dentin adhesives examined were able to cover exposed root dentin, they all exhibited fluid transudation through the polymerized adhesives. Dentin adhesives were also susceptible to surface degradation after lactic acid challenge. As simplified self-etch adhesives were highly water permeable and exhibited the most extensive surface damage, they may not be the best adhesives to be used for long-term dentin desensitization. These preliminary in vitro findings warrant validation in vivo.     

Evaluation of the bonding effectiveness of a universal adhesive to the plasma-activated dentin surface

This study aimed to evaluate the effect of non-thermal atmospheric pressure plasma on the bond strength of a universal adhesive used in etch-and-rinse mode. Dentin surfaces were etched with phosphoric acid and samples were divided into groups exposed to either dry bonding, plasma-dried bonding, plasma-dried and rewetted bonding, or wet bonding (n  =  10). Dentin surfaces of the plasma-dried specimens were treated with a plasma jet before the adhesive procedure. After application, composite blocks were built, and specimens were subjected to micro-tensile bond strength testing after 24 h and after 10,000 thermal cycles. The hybrid layer formation was evaluated by micro-Raman spectral analysis; the resin–dentin interface was analyzed by scanning electron microscopy. One-way ANOVA and Tukey's post hoc multiple comparison tests were used to statistically analyze the data. The bond strength values of the plasma-dried bonding groups were statistically higher than the non-plasma-treated groups both before and after aging. After the thermal cycles, bond strength values decreased significantly only in the wet bonding group. Micro-Raman spectral analysis revealed that plasma-drying increased adhesive penetration, especially hydrophobic monomer infiltration. This may increase the mechanical properties and durability of the resin–dentin interface, provide long-term stability, and improve the polymerization rate of the adhesive layer.     

Voids formation along the bonding interface between a smeared dentin surface and all-in-one adhesives

It has been reported that the adhesive resin layer of all-in-one adhesives is permeable and allows the formation of a water channel or water tree. The effects of a smear layer on the ultra-structure of bonding interface created with three all-in-one adhesives and a resin composite were evaluated in this study. Dentin surface was ground with of 180-, 600-, or 2000-grit SiC paper to produce different smear layer thickness. The bonding interfaces were observed under a transmission electron microscope without demineralization. Voids of various sizes and water channels were found at the bottom of the adhesive resin layer along the bonding interface of SiC 180-grit dentin, while SiC 2000-grit dentin did not produce any voids. The results showed that the voids were possibly related to water that had penetrated from the underlying dentin. A smear layer may have an adverse influence on the bonding performance of all-in-one adhesives to dentin.     

The induction of oxidative stress, cytotoxicity, and genotoxicity by dental adhesives.

OBJECTIVES: Polymerized dental resin materials release residual monomers that may interact with pulp tissues. We hypothesized that dental adhesives might cause cytotoxicity in pulp cells via the generation of reactive oxygen species (ROS), which may also contribute to genotoxic effects in vitro. METHODS: For cytotoxicity testing, transformed human pulp-derived cells were exposed to extracts of primers and bonding agents of Clearfil SE bond, Clearfil Protect bond, AdheSE, Prompt L-Pop, and Excite for 24h. The cytotoxicity of the same materials was also analyzed in a dentin barrier test device using three-dimensional pulp cell cultures. The generation of ROS in monolayer cultures was measured after a 1h exposure period by flow cytometry (FACS), and genotoxicity as indicated by the formation of micronuclei was determined in V79 cells after a 24h exposure period. RESULTS: The dentin primers and bonding agents decrease cell survival in a dose-related manner. Cytotoxicity of bonding agents based on concentrations which caused 50% cell death (EC50) were ranked as follows: Excite (0.16 mg/ml)>AdheSE bond (0.30 mg/ml)>Clearfil Protect bond (0.35 mg/ml)>Clearfil SE bond (0.37 mg/ml), and Prompt L-Pop bond (0.68 mg/ml). Dentin primers were about 10-fold less effective. In contrast, no cytotoxic effects of the dental adhesives were observed in a dentin barrier test device. Yet, all dental adhesives increased the amounts of ROS about fivefold in pulp cells in a dose-related manner, and, again, the bonding agents were more efficient than the dentin primers. Finally, the number of micronuclei was increased about sixfold by extracts of the AdheSE primer. SIGNIFICANCE: Our results suggest that the cytotoxic potencies demonstrated by these materials might be of clinical relevance, since all dental adhesives disturbed the cellular redox state of pulp cells in monolayer cultures. As a result, the concentrations of biologically active ingredients of some of the agents may be high enough to modify pulp cell metabolism when the materials are used in deep cavities or directly contact pulp tissue.     

Shear bond strength of Scotchbond in vivo

The shear bond strengths of Scotchbond, HEMA/Scotchbond, and Scotchbond 2 were measured in vivo in dog canine and molar enamel and dentin. Dentin bond strengths were compared in superficial, middle, and deep dentin. The acid-etched enamel bond strengths of the three bonding systems ranged from 10 to 11 MPa and were not statistically different. Scotchbond/Silux bonds to superficial and middle cuspid and molar dentin were 3 MPa and were not statistically different. HEMA-treated dentin did not consistently improve Scotchbond strengths to either tooth type at any dentin depth. Deep dentin from either tooth type yielded significantly lower bond strengths. Scotchbond 2/Silux shear bond strengths were significantly higher (6-8 MPa) in superficial and middle cuspid dentin but were not different from Scotchbond bonds made to deep cuspid dentin or to any depth of molar dentin. The observation that molar bond strengths are lower than those made to cuspid dentin indicates that there are important substrate differences between teeth as well as within dentin as a function of depth. The dog model may be useful for the screening of new dentin bonding systems prior to clinical trials.     

Dentin as a bonding substrate

Dentin comprises the largest dental structure available for bonding. Because of its inherent morphological and physiological characteristics, reliable and durable resin–dentin bonding remains a challenging accomplishment that is subjected to multi‐factorial interferences. Adhesive technology has evolved significantly over the past decade, resulting in improved predictability of resin–dentin bonds. This article reviews the present knowledge regarding resin–dentin bonding from the perspective of the dentin substrate. Since another article in the previous issue of Endodontic Topics already covers dentin structure and composition, the intention is not to fully review these aspects. Instead, basic principles of current bonding strategies used by adhesive agents are presented. Specific attention is given to describing how the morphology and physiology of dentin affect existing bonding mechanisms, how some chemical treatments of dentin can affect its properties and bonding, and finally how bonding to root canal dentin is currently viewed and understood.     

Bonding to caries-affected dentin

Dentin adhesive systems have dramatically developed during the past decades. In a prepared cavity for an adhesive composite restoration, large areas of the cavity floor are composed of caries-affected dentin after removal of caries-infected dentin, not normal dentin. Caries-affected dentin is different in morphological, chemical and physical characteristics from normal dentin. Therefore, caries-affected dentin has still problems as bonding substrate compared with normal dentin. That is, caries-affected dentin produces lower bond strength and poor quality of the hybrid layer than normal dentin. In addition, when exposed the adhesive interface of caries-affected dentin in oral environment, the poor quality of the hybrid layer would compromise the longevity of the composite restoration due to hydrolysis of the resin and collagen fibrils. The improvement of bonding potential to caries-affected dentin could lead to reinforcement of tooth-composite restoration complex, protecting secondary caries and tooth fracture.     

Influence of dentin bonding agents and polymerization modes on the bond strength between translucent fiber posts and three dentin regions within a post space

STATEMENT OF PROBLEM: Debonding is the most frequent failure encountered with translucent fiber posts and usually occurs along the post space dentin-adhesive interface. PURPOSE: The purpose of this study was to evaluate the effect of different dentin bonding agents and polymerization modes on the bond strength between translucent fiber posts and root dentin in different regions of the post space. MATERIAL AND METHODS: Forty maxillary canines with similar root lengths were selected, sectioned at the cemento-enamel junction, and the roots were endodontically treated. Following post space preparation, the roots were divided into 4 groups of 10 specimens each, and the post spaces were treated with 1 of 4 different dentin bonding agents: light-polymerized, single-bottle bonding agent Excite (Group EX); dual-polymerized, single-bottle bonding agent Excite DSC (Group EX-DSC); self-etching primer Clearfil Liner Bond 2V with a light-polymerized bonding agent, Bond A (Group CL-LC); or self-etching primer Clearfil Liner Bond 2V with a dual-polymerized bonding agent, Bond A+B (Group CL-DC). Translucent fiber posts (D.T. Light-Post), 2.2 mm in diameter, were luted (Panavia F) in each specimen after respective dentin bonding procedures. The roots were cut into 3-mm-thick sections, perpendicular to the long-axis in cervical, middle, and apical post space dentin. Push-out tests were performed with a universal testing machine at a crosshead speed of 0.5 mm/min, and bond strength values (MPa) were calculated by dividing the force at which bond failure occurred by the bonded area of the post. The data were analyzed with 1- and 2-way analysis of variance and Tukey multiple comparison tests (alpha=.05). Dentin adhesive bonding mechanisms in different regions of the post spaces were evaluated with a scanning electron microscope. RESULTS: The highest mean bond strength values were obtained for Group CL-LC (18.3 +/- 4.1 MPa). The dual-polymerized bonding agent resulted in significantly lower bond strength (P<.001) in combination with self-etching primer (Group CL-DC) (13.2 +/- 2.5 MPa). The light-polymerized and dual-polymerized single-bottle bonding agents provided similar bond strengths (12.7 +/- 5.0 for EX; 13.5 +/- 5.3 for EX-DSC). The regional bond strength values of single-bottle bonding agents were reduced significantly in apical post space dentin (P<.001). Self-etching primers did not demonstrate regional differences in post space dentin bonding and dense resin tags were apparent. CONCLUSION: Data suggests that the self-etching primer system used in this study was unaffected by the morphological variations in the post space dentin compared to the single-bottle bonding agents. Dual polymerization did not improve the bond strength values of the bonding agents tested.     

Bond strength of dentinal bonding agents to chemomechanically prepared dentin

The aim of this investigation was to compare the shear bond strengths of 5 commercially available dentinal bonding agents to remaining dentin after chemomechanical caries removal (Caridex^TM) with the strengths obtained after caries removal with conventional mechanical drilling; and to examine the dentin/resin interface. One hundred freshly extracted carious teeth were randomly assigned for caries removal with either the chemomechanical technique or with conventional mechanical drilling. Caries removal was continued until the remaining dentin surfaces were judged sound. In addition, 50 sound teeth were ground on 600 grit SiC to provide a control group. Groups of 10 teeth were assigned for bonding with each of the 5 dental bonding agents. All bonded specimens were stored in water at 37°C for 24 h. Shear bond strength was tested using an Instron testing machine at a cross-head speed of 0.05 cm/min. Analysis of variance showed that the 5 materials tested produced significantly different bond strengths (p<0.001). For the 5 dentinal bonding agents evaluated, chemomechanically-treated dentin provides at least comparable, and probably superior, 24 h bond strengths compared with dentin that has been mechanically prepared.     

Cytotoxicity test of dentin bonding agents using millipore filters as dentin substitutes in a dentin barrier test

Objectives

The purpose of this study was to find proper dentin substitute for standardized dentin barrier test and perform the cytotoxicity test of commercial bonding agents with the proper substitute.

Materials and methods

The three-dimensional cells attached to dentin disc or millipore filters as the dentin substitute were tested in a dentin barrier test by perfusion. MTT assay was performed as an evaluation method for the cell survival rate. The cytotoxicity test of serial phenol dilution by bovine dentin disc was done to determine a standard toxic material, and the test of this proper phenol by using various millipore combinations was performed to find the suitable dentin substitute. Also, the cytotoxicity test of bonding agents was performed by this standardized substitute. The cell viability was expressed as percentages of untreated group.

Results

Phenol concentration of 0.05 % was selected as the standard toxic material. The different combinations of millipore filters—two sheets of 0.45 μm, two sheets of 0.22 μm, and the combination of 0.65, 0.45, and 0.22 μm—showed similar cytotoxicity to natural dentin discs by 0.05 % phenol (p?>?0.05). The millipore combination of 0.65, 0.45, and 0.22 μm that had structural similarity to natural dentin discs was used as the substitute for cytotoxicity test of bonding agents. The toxic level of Adper Prompt L-Pop using the selected substitute was significantly the highest among four kinds of dentin bonding agents (p?<?0.05). Also, the dentin barrier test by the substitute showed constant results compared with the one by the natural dentin disc.

Conclusions

The millipore filter combination of 0.65, 0.45, and 0.22 μm could be used as the substitute for the cytotoxicity test of materials applied to dentin.

Clinical relevance

Dentin barrier test by standardized substitutes would be helpful for considering the potential toxicity of dentin bonding agents prior to clinical adaptations and reducing the variations of natural bovine dentin that has individually different characteristics.     

牙本质基质在组织再生中的应用

组织器官病变严重影响到人们的生活质量,组织器官缺损可能威胁人们的生命,组织、器官缺损的修复和功能重建是现代医学面临的挑战。组织工程为再生组织器官带来希望。组织工程支架为细胞的生长、增殖和分化提供了微环境,而且影响着形成组织的大小和形态。牙本质基质作为一种天然的生物活性支架,具有良好的生物相容性,在组织工程中得到广泛的应用,成为研究热点。学者们以牙本质基质为支架,开展了包括牙根、牙周、牙髓、骨等软硬组织缺损修复的研究,取得了一系列重要进展。本文对牙本质生物学特性、牙本质基质在组织再生中的应用等进行综述,为临床应用牙本质基质进行组织再生提供参考。     

Identification of collagen encapsulation at the dentin/adhesive interface

PURPOSE: The purpose of this study was to investigate the dentin/adhesive interfacial characteristics of three current commercial adhesives with different relative hydrophilic/hydrophobic composition, using a nondestructive staining technique. MATERIALS AND METHODS: Dentin surfaces of 18 unerupted human third molars were randomly selected for treatment with one of three commercial dentin bonding agents according to manufacturers' instructions for the "wet" bonding technique. The adhesives were ranked based on hydrophilic/hydrophobic component ratios (ie, ability to dissolve in water), highest to lowest, as follows: Uno (Pulpdent) > Prime&Bond NT (PBNT, Dentsply Caulk) > Single Bond (SB, 3M ESPE). Dentin/adhesive (d/a) interface sections were stained with Goldner's trichrome, a classical bone stain, and examined using light microscopy. RESULTS: The extent and degree to which the adhesive encapsulates the demineralized dentin matrix is reflected in the color differences in the stained sections. The depth of demineralization appeared comparable among these bonding systems, but adhesive infiltration varied from highest to lowest as follows: Uno > PBNT > SB. CONCLUSIONS: The differential staining technique provided a clear representation of the depth of dentin demineralization and extent/degree of adhesive encapsulation of the exposed collagen at the d/a interface. This technique provides a mechanism for readily identifying vulnerable sites at the d/a interface. The composition of the one-bottle adhesive systems has a substantial effect on the interfacial structure of the d/a bond.     

Ultra-morphological characteristics of dentin surfaces after different preparations and treatments

Using transmission electron microscopy (TEM), this study investigated the characteristics of smear layers after preparation of dentin surfaces using different methods. In addition, this study analyzed, using scanning electron microscopy (SEM), the interactions of smear layers with the various acidic agents used subsequently to treat the dentin surface. Mid-coronal dentin surfaces were prepared according to one of five instrumentation methods: fracture; grinding with carbide bur; grinding with regular-grit diamond bur; grinding with superfine-grit diamond bur; or grinding with 600-grit silicon carbide (SiC) abrasive paper. Then, each prepared dentin surface was further divided into control (no further treatment) or treatment with one of the following agents: phosphoric acid solution (PAS); phosphoric acid gel (PAG); Clearfil SE Bond 2 Primer (SE2); or Scotchbond Universal Adhesive (SBU). Longitudinal ultra-thin sections were made for TEM observations. Dentin discs, representing each surface preparation and treatment method described above, were created, and the morphology was examined by SEM. The TEM results revealed differences in thickness and denseness of the smear layer, according to the different methods of instrumentation used to prepare the dentin surface. The two forms of phosphoric acid completely removed the smear layer in all groups. Agglomerated silica particles were observed on the top of the collagen layer after etching with PAG. For all dentin surfaces, except for that prepared with SiC, SE2 demonstrated better etching efficacy on different smear layers, whereas SBU provided only superficial interaction.     

The effect of dentin hypersensitivity treatments on the shear bond strength to dentin of a composite material

This study sought to evaluate the influence of a dentin desensitizer and ozone application on the bond strength to dentin of a composite resin material. The dentin desensitizing agent and ozone treatment were applied on the cervical dentin surfaces of extracted, caries-free, erupted third molars. Dentin surfaces that received no treatment were used as control samples. A dentin bonding agent was applied according to the manufacturer's instructions and an adhesion test was performed according to ISO/TS 11405. Statistical analysis showed no significant influence of the different hypersensitivity treatments on shear bond strength to dentin (ANOVA and Tukey's tests, p > 0.05). Within the limitations of this in vitro study, it appears that the short-term use of dentin hypersensitivity treatments like ozone and dentin desensitizers containing gluteraldehyde do not further affect the shear bond strength to dentin of subsequent composite resin restorations.