One-bottle Adhesives Research Articles

Influence of resin-coating on bond strength of resin cements to dentin and CAD/CAM resin block in single-visit and multiple-visit treatment.

The purpose of this study was to evaluate the influence of resin-coating using one-bottle adhesives on the bond strength of resin cements in single-visit and multiple-visit treatments. Three one-bottle adhesives were used for resin-coating and/or pre-treatment adhesives prior to cementation, in conjunction with resin cements from the same manufacturers: Clearfil Universal Bond Quick with Panavia V5 (UBQ/Pv5), Scotchbond Universal Adhesive with RelyX Ultimate (SBU/RxU), and Optibond All-in-one with NX3 Nexus (OP/NX3). Bovine dentin surfaces were left uncoated or resin-coated. After 1-h water storage (single-visit) or 1-week water storage with a non-eugenol temporary cement (multiple-visit), a CAD/CAM resin block was cemented to uncoated or resin-coated dentin surfaces. Microtensile bond strengths (µTBSs) were measured and statistically analyzed (α=0.05). Application of resin-coating improved µTBSs. The multiple-visit group exhibited lower values of µTBS than the single-visit group. Selection of the materials affected µTBSs. Resin-coating and single-visit treatment are desirable for CAD/CAM resin composite restorations.

Influence of different surface treatments on zirconia/resin shear bond strength using one-bottle universal adhesive

ABSTRACTThis study was designed to evaluate the effect of different treatments on the zirconia/resin shear bond strength (SBS) using commercial one-bottle universal adhesive. Zirconia discs with different surface treatments (blank control; airborne-particle-abrasion; glazing) were bonded to the bovine enamel surfaces using one-bottle universal adhesive. All specimens were tested for SBS (MPa) before and after 10000 thermocycles. Statistically analysis were conducted by using one-way analysis of variance and multiple-comparison least significant difference tests (α = 0.05). Airborne-particle-abrasion group showed higher SBS (36.19 ± 11.86) than control group (14.98 ± 5.90) and glazing group (10.63 ± 5.39) (p < 0.05). After thermocycling test, the SBS significantly decreased for control group (8.84 ± 2.55) and glazing group (6.18 ± 2.78) while not for airborne-particle-abrasion group (41.5 ± 7.95). One-bottle universal adhesives combined with airborne-particle-abrasion showed quite high SBS of zirconia/resin, which was appropriate for bonding of zirconia restoration.

Clinical evaluation of two one-bottle dentin adhesives at three year

Clinical evaluation of two one-bottle dentin adhesives at three year

NaOCl degradation of one-step one-bottle self-etch adhesives bonded to bovine dentine

Objective: The aim of the present study was to assess the influence of an in vitro aging regime (NaOCl storage) on dentine microtensile bond strength (μTBS) of five one-step one-bottle self-etch adhesives in comparison with bond strength of two-step self-etch adhesive.Material and methods: Flattened dentine surfaces from 30 bovine incisors were bonded with five one-step one-bottle self-etch adhesives (iBond, Clearfil S3 Bond, AdheSE One F, G-Bond, Optibond all-in-one) and one two-step self-etching adhesive (Clearfil SE Bond). Composite buildups were done with microhybrid resin composite. Bonded samples were sectioned into resin–dentine sticks of 0.8 mm2 cross section. Randomly selected 20 sticks were tested directly by microtensile bond strength testing machine, whereas another randomly selected 20 sticks were tested after being stored in solution of 10% NaOCl for 5 h. Data were analyzed by two-way analysis of variance (ANOVA) and Tukey’s honest significant difference (HSD) tests (p < 0.05).Results: All adhesives exhibited similar dentine bond strength with exception of G-Bond. After NaOCl storage, μTBS reduced in all groups significantly. The lowest μTBS were found for G-Bond. Rest of one-step self-etch adhesives presented similar μTBS with two-step self-etch adhesive.Conclusion: Interfaces of resin–dentine bonding are susceptible to NaOCl degradation. The amount of the destruction depends on adhesive system. NaOCl degradation of the nonresin encapsulated collagen fibers might decrease long-term stability of resin bonding with dentine.

Comparison of tensile bond strengths of four one-bottle self-etching adhesive systems with Er:YAG laser-irradiated dentin

This study aimed to investigate the interaction of current one-bottle self-etching adhesives and Er:YAG laser with dentin using a tensile bond strength (TBS) test and scanning electron microscopy (SEM) in vitro. Two hundred and thirteen dentin discs were randomly distributed to the Control Group using bur cutting and to the Laser Group using an Er:YAG laser (200mJ, VSP, 20Hz). The following adhesives were investigated: one two-step total-etch adhesive [Prime & Bond NT (Dentsply)] and four one-step self-etch adhesives [G-Bond plus (GC), XENO V (Dentsply), iBond Self Etch (Heraeus) and Adper Easy One (3M ESPE)]. Samples were restored with composite resin, and after 24-hour storage in distilled water, subjected to the TBS test. For morphological analysis, 12 dentin specimens were prepared for SEM. No significant differences were found between the control group and laser group (p=0.899); dentin subjected to Prime & Bond NT, XENOV and Adper Easy One produced higher TBS. In conclusion, this study indicates that Er:YAG laser-prepared dentin can perform as well as bur on TBS, and some of the one-step one-bottle adhesives are comparable to the total-etch adhesives in TBS on dentin.

Effect of hydrophilicity on the compatibility between a dual-curing resin cement and one-bottle simplified adhesives.

To evaluate the effect of the hydrophilicity of adhesives on the compatibility between one-bottle simplified adhesives and a dual-curing resin cement. Three experimental and two commercial adhesives (All-Bond Universal, OptiBond Allin- One) with the same or similar pH and various degrees of hydrophilicity were tested in this study. Extracted human dentin was treated with each adhesive and bonded with a dual-curing resin cement (Duolink), which was either light cured or chemically (self) cured (n = 10). Shear bond strength was tested using the Ultradent jig method, and failure modes were determined using a stereomicroscope. Water contact angle (as a measure of hydrophilicity/-phobicity) was measured on a fully cured adhesive (n = 10). The data were analyzed statistically by ANOVA and Tukey's test. The quantitative relationship between the hydrophilicity and bond strength differences was analyzed (confidence level 95%). Among the experimental adhesives, differences in bond strengths between light-curing and self-curing modes were larger for the more hydrophilic adhesives. For the commercial adhesives, Optibond All-in-One had a lower contact angle than All-bond Universal (p < 0.05). Bond strength (MPa) values for Optibond All-in-One and All-bond Universal were 29.6 and 31.5, respectively (light cured), and 1.9 and 30.0, respectively (self-cured). Adhesive failure was a predominant mode for all adhesives except for All-Bond Universal. Regression analysis indicated a linear correlation between adhesives' hydrophilicity and bond strength differences (p < 0.05). The more hydrophilic adhesives were less compatible (larger bond strength differences between different curing modes) with this dual-curing resin cement. All-bond Universal is more hydrophobic than Optibond All-in-One and it is compatible with this self-/dual-curing resin cement.

Impact of oxalate desensitizer combined with ethylene-diamine tetra acetic acid-conditioning on dentin bond strength of one-bottle adhesives during dry bonding

Background:Elimination of water entrapment in hybrid layer during bonding procedure would increase bonding durability.Aims:This study evaluated the effect of oxalate desensitizer (OX) pretreatment on bond strength of three one-bottle adhesives to ethylene-diamine tetra acetic acid (EDTA)-conditioned dentin under dry bonding.Materials and Methods:Three adhesive systems, One-Step Plus (OS), Optibond Solo Plus (OP) and Adper Single Bond (SB) were bonded on dentin surfaces under four bonding conditions: (1) Wet-bonding on acid-etched dentin, (2) wet bonding on EDTA-conditioned dentin, (3) dry bonding on EDTA-conditioned dentin, (4) dry bonding associated with OX on the EDTA-conditioned dentin. After storage and thermo cycling, shear bond strength test was performed. Data were analyzed using two-way analysis of variance and Tukey tests.Results:Wet bonding with EDTA or acid etching showed similar bond strength for test adhesives. Dry bonding with EDTA significantly decreased the bond strength of OS, but it had no effect on the bonding of OP and SB. OX application in the forth bonding condition, in comparison with the third condition, had a negative effect on the bond strength of OP, but not influence on OS and SB.Conclusions:The use of an OX on EDTA-conditioned dentin compromised the bonding efficacy of OS and OP under dry bonding but compatible for SB.

Cross-Compatibility of Methacrylate-Based Resin Composites and Etch-and-Rinse One-Bottle Adhesives

To compare dentin shear bond strength (SBS) of four combinations of light-activated one-bottle adhesives and composites to determine if cross-compatibility exists, and to determine if the use of the same manufacturer's adhesive and composite results in higher SBS than systems that combine different manufacturers' products. One hundred sixty human third molars were used for bonding (n=10). Specimens were treated with 37% phosphoric acid and one of four etch-and-rinse adhesives. Specimens were placed in a bonding jig, which was filled with one of four composites. Adhesives PQ1 (Ultradent), Excite (Ivoclar-Vivadent), Optibond Solo Plus (Kerr), and Single Bond (3M-ESPE) and composites Vit-l-Escence (Ultradent), Four Seasons (Ivoclar-Vivadent), Premise (Kerr), and Filtek Supreme Plus (3M-ESPE) were tested. SBS was measured at 24 hours and three months with a testing machine at a speed of 1 mm/min and expressed in MPa. A three-way analysis of variance and Tukey tests were used for data analysis. Significant differences were evidenced among composites for each adhesive system (p<0.001) and among adhesives for each composite system (p<0.001). Optibond Solo Plus and PQ1 yielded significantly higher bond strengths than Single Bond and Excite for all composite systems (p<0.05). All combinations, with the exception of two, demonstrated a decrease in bond strength values after aging. Cross-compatibility was demonstrated, indicating that etch-and-rinse one-bottle adhesive systems can be safely used with composites from different manufacturers without a compromise to the bond strength. Moreover, even higher mean SBS values were demonstrated for selective combinations of different manufacturers' products

Bonding of self-etching adhesives on dehydrated dentin.

This study examined the effect of dentin pretreatment with acetone or ethanol on bonding of one-bottle self-etching vs two-step self-etching adhesives to evaluate the effect of hydration on bond strength. The bond strengths of resins were measured using two one-bottle and two two-step selfetching adhesives that bonded to wet dentin (control), or acetone- or ethanol-pretreated dentin. Wet dentin is the normal substrate for bond testing, and in the pretreatment groups, 95% acetone or ethanol was applied to the dentin surface for 30 s before bonding. Weight of resin adhesives before and after evaporation was measured to evaluate the extent of the solvent contents in the adhesives. Furthermore, phase separation of adhesives was morophologically investigated by in situ light-microscopic observation to evaluate the hydrophilicity of the adhesive resins. The bond strengths of the acetone and ethanol groups for one-bottle adhesives were significantly greater than for the control (p < 0.05). However, significantly lower bond strengths were found in the pretreatment groups for the two-step self-etching adhesives (p < 0.05). The bond strength depended on the wetness of the bonding substrate for both adhesive groups, with a positive effect in bond strength for one-bottle adhesives and a negative effect for two-bottle self-etching adhesives. The acetone- or ethanol-pretreated dentin surfaces may provide an improved substrate for resin adhesion of hydrophilic self-etching adhesives such as one-bottle self-etching adhesives due to dentin dehydration.

Enamel bond strength of one-bottle adhesives following treatments with CPP-ACP

Enamel bond strength of one-bottle adhesives following treatments with CPP-ACP

Effect of Light Activation Mode on the Incompatibility Between One-bottle Adhesives and Light-cured Composites: An In Vitro Shear Bond Strength Study

This study examined the effect of different light activation modes for light-cured resin-based composites on the shear bond strength to dentin of two one-bottle adhesives with differing acidity. In this experimental study, a flat middle dentin surface was prepared on 110 extracted sound molars using a 600-grit polish paper. The teeth were then randomly divided into 10 equal groups (n = 11). One-Step Plus (OS) and Prime & Bond NT (P&B NT) were used according to the manufacturer's instruction with their respective composite (Aelite, Spectrum TPH) applied and cured using five different light-activation modes: 1. Conventional (CO): 600 mW/cm2 (40 seconds) 2. Soft-Start I (SSI): 100 mW/cm2 (10 seconds) 600 mW/cm2 (30 seconds) 3. Soft-Start II (SSII): 200 mW/cm2 (10 seconds), 600 mW/cm2 (30 seconds) 4. Pulse-Delay I (PDI): 100 mW/cm2 (3 seconds), 3-minute delay, 600 mW/cm2 (37 seconds) 5. Pulse-Delay II (PDII): 200 mW/cm2 (3 seconds), 3-minute delay, 600 mW/cm2 (37 seconds) After 24 hours storage in distilled water at room temperature, a shear bond strength (SBS) test was performed using an Instron machine at 1 mm/minute and the results were recorded in MPa. Statistical analysis included two-way ANOVA and Tukey HSD (p < 0.05). The highest SBS (MPa) was shown in the OS conventional group (19.62 +/- 2.21) and the lowest SBS was shown in P&B NT, PDII (5.93 +/- 1.79). In each group of five curing modes, the mean SBS for P&B NT was significantly lower than OS: conventional mode--P&B NT (17.27 +/- 1.98) vs OS (19.62 +/- 2.21); SSI-P&B NT (10.84 +/- 2.82) vs OS (13.09 +/- 1.24); SSII - P&B NT (14.78 +/- 1.63) vs OS (18.79 +/- 1.57); PDI-P&B NT (5.93 +/- 1.79) vs OS (11.97 +/- 2.59) and PDII-P&B NT (11.82 +/- 1.24) vs OS (16.00 +/- 1.62) (p < 0.001 for all comparisons). For each of the adhesives, the ranking of SBS was as follows: CO > SSII > PDII > SSI > PDI, with the two-paired comparisons of curing modes being significantly different (p < 0.05). The results of the current study indicated that the bond strength of P&B NT might be compromised by the higher acidity of this adhesive compared to OS during each curing mode, especially PDI. The conventional mode was least affected by the acidity of the adhesive.

An eight-year clinical evaluation of filled and unfilled one-bottle dental adhesives

The strategies for accomplishing resin adhesion to dentin involve surface conditioning, priming and bonding. One-bottle adhesives combine the priming and bonding functions in a single solution. In this study, the authors compared the eight-year clinical performance of two one-bottle adhesives made by different manufacturers. The authors placed a total of 99 Class V restorations using either a filled, ethanol-based adhesive (OptiBond Solo [OS], SDS Kerr, Orange, Calif.) or an unfilled, acetone-based adhesive (Prime & Bond 2.1 [PB] Dentsply Caulk, Milford, Del.) and a hybrid resin-based composite in 33 subjects with noncarious cervical lesions. The authors did not bevel the enamel margins and used no mechanical retention. They evaluated the restorations at baseline and for as long as eight years after placement using modified U.S. Public Health Service criteria. They analyzed differences between groups using appropriate statistical tests. The authors examined 56 restorations after eight years and found retention rates of 69 percent for OS and 59 percent for PB. These rates did not differ statistically (P = .449) and were not significantly affected by subject or lesion characteristics. The authors noted marginal discoloration on 55 percent of the retained OS restorations and on 31 percent of the retained PB restorations, but they detected no secondary caries around any restoration. They noted poor anatomical form and poor marginal adaptation in 15 percent and 40 percent of the retained OS restorations, respectively. The performance of both adhesives was good during this eight-year clinical trial. The filled, ethanol-based adhesive OS demonstrated slightly better bond durability than did the unfilled, acetone-based adhesive PB, but the difference between the two materials was not statistically significant. Despite a high incidence of marginal discoloration, the one-bottle adhesives evaluated in this study provided good clinical retention of Class V restorations without mechanical retention. When the materials are used properly, restorations are retained at an acceptable rate through at least eight years of clinical service.

Effect of repeated use on dentin bond strength of two adhesive systems: All-in-one and one-bottle

To compare the effects of repeated use of two one-bottle adhesives with that of two all- in- one adhesives (with acetone solvent) on bond strength to dentin. A flat dentin surface was prepared on 120 bovine incisors using 600- grit abrasive pape. The teeth were randomly assigned into 12 equal groups. The four adhesive systems [Prime and Bond NT (P&B NT), One-Step Plus (OS), iBond (iB), and G-Bond (GB)] were used at baseline, after the lid of the container had been opened 30 times, and after it had been opened 60 times. Before each use of the adhesives, the lids of the containers were left open for 1 min. The resin composites were applied on the dentin in a cylindrical split mold. After thermocycling, shear bond strength test was performed with a universal testing machine at 1 mm/min. We used Kruskal-Wallis and Dunn tests for statistical analysis. There was no statistically significant difference among bond strength (MPa) of the groups of P&B NT (31.9 +/- 4.6, 31.8 +/- 6.5, 26.1 +/- 6.7) and OS (33.2 +/- 5.1, 30.9 +/- 7, 29.3 +/- 5.9), respectively (P > 0.05). The mean of the bond strength of iB and GB after 60 times (15.3 +/- 4.1 and 12.2 +/- 3.9, respectively) was significantly lower than that of iB and GB at baseline (23.5 +/- 4.8 and 22.2 +/- 4.5, respectively) (P < 0.05). Repeated use (60 times) of the all-in-one adhesive led to a decline in the dentin bond strength. To avoid this problem it would be advisable to have containers with smaller amounts of adhesive or perhaps those with only a singe dose.

Effect of dentinal water on bonding of self-etching adhesives

This study examined the effect of dentinal water on bonding, comparing one-bottle and two-step self-etching adhesives using microtensile bond test and scanning electron microscope. The bond strength of resin to dentin was measured for wet dentin (control) and dry dentin substrates. Wet dentin is the normal substrate for bond testing, whereas dry dentin was dehydrated in a desiccator at different drying times (5 to 60 min) before bonding. After bond testing, the fractured surfaces were examined. Although no correlation was found for two-step self-etching adhesives, the bond strength of the dry-dentin was significantly increased with the increase in the drying-time for one-bottle adhesives. With increased drying-time, the amount of water-bubbles was decreased for one-bottle adhesives; however, no bubble formation was seen in two-step adhesives in any group. The hydrophilic resin adhesive may entrap the water from dentin by osmosis during and after bonding. This effect may depend on the "hydrophilicity" of adhesives.

Shear Bond Strength of Two Resin Cements to Human Root Dentin Using Three Dentin Bonding Agents

This study compared the bond strength of two resin cements to human root dentin when used with three bonding agents. The materials used were Rely X ARC and Perma Cem, two one-bottle bonding agents (Single Bond, Bond-1) and one self-etching bonding agent (Clearfil SE Bond). The dentin was obtained from single rooted human teeth, and the specimens were treated with either 15% EDTA or 37% phosphoric acid to remove the smear layer, except in groups where the self-etching bonding agent was used. The resin cements were placed on dentin surfaces with the use of bonding agents. Shear bond strength (SBS) was tested using a single plane shear test assembly. The dentin specimens were divided into 10 groups. Eight groups were pre-treated with EDTA or phosphoric acid to remove the smear layer, followed by a bonding agent (Bond-1 or Single Bond) and resin cement (Rely X or Perma Cem). In the two remaining groups, the smear layer was left intact, and the two resins cements were used in combination with the self-etching bonding agent (Clearfil SE Bond). No statistically significant differences were observed among the eight groups treated with one-bottle bonding agents. The mean bond strengths of the two groups treated with the self-etching bonding agent did not differ significantly from each other but were both significantly greater than the bond strengths of all the other groups. The results of this study also showed that EDTA can be used as an alternative to phosphoric acid in bonding procedures for resin cements. However, the bond strengths of resin cements, in combination with a self-etching bonding agent, were significantly greater than those of the same cements when used with one-bottle bonding agents.

One-bottle adhesives: in vitro analysis of solvent volatilization and sealing ability

The aim of this study was to compare the solvent volatilization rate and evaluate the sealing ability of different one-bottle adhesives that were in constant clinical use--an ethanol/water-based adhesive (Single Bond, 3M/ESPE-SB) and an acetone-based adhesive (Prime & Bond 2.1, Dentsply/Caulk-PB). Nine bottles of each agent were collected from the clinics of a dental school, and new ones were used as controls. The weight of all bottles and of empty bottles was determined using an analytical balance. A drop of each solution was dispensed onto the balance, taking its initial weight (IW) and, after 10 min, its final weight (FW). The IW/FW ratio was used to determine the solvents volatilization rate. The bottles with the highest evaporation levels (SB Control and PB Control) and with the lowest evaporation levels (SB Test and PB Test) of each agent were applied in Class V restorations with margins in dentin. Specimens were thermocycled and immersed in a 0.5% basic fuchsin solution. Dye penetration was evaluated under magnification and the data were submitted to the Kruskal-Wallis test. Solvent volatilization was faster for the acetone-based adhesive. IW/FW ratios ranged from 1.239 to 1.515 for SB, and from 3.488 to 6.476 for PB. The PB-Control and SB-Control groups exhibited similar microleakage patterns. The highest dye penetration scores were found for the PB-Test group (p < 0.05). Results indicate that the sealing ability can be affected by the repeated opening of acetone-based adhesive bottles.

A three-year clinical evaluation of two-bottle versus one-bottle dentin adhesives

The authors conducted an in vivo investigation to compare the clinical performance of two commercial one-bottle adhesives and a two-bottle adhesive for restoration of noncarious cervical lesions (NCCLs). The patient pool consisted of 57 patients and 171 teeth (three teeth per patient), with one NCCL per tooth. Each patient received three resin-based composite restorations, each with a different adhesive: one tooth with a two-bottle, water-based adhesive as the control; another tooth with a one-bottle, ethanol-based adhesive; and a third tooth with a one-bottle, solvent-free adhesive. The authors assessed restorations in terms of retention, marginal integrity, margin discoloration and air sensitivity at baseline, six months, one year, two years and three years after initial placement. The retention rates at 36 months were 88 percent for the first adhesive, 81 percent for the second adhesive and 90 percent for the third adhesive. No statistically significant differences in retention rates could be shown, with 86 percent of restorations retained overall. Measures of marginal integrity, marginal discoloration and sensitivity also had no statistically significant differences between the three adhesives (P > .05). All three adhesives performed with acceptable outcomes after a 36-month period, with small differences between the one- and two-bottle systems and between the various solvents. Retention rate was moderately high and air sensitivity was markedly reduced; however, superficial marginal discoloration and marginal degradation was notable. Certain lesion, tooth and patient characteristics may predispose restorations to retention failure. The type of solvent may not be a major factor in retention of Class V restorations in NCCLs. Both single-bottle adhesives and conventional two-bottle adhesives performed acceptably.

Effect of dentine conditioners on the bonding efficacy of one‐bottle adhesives

The bonding efficacy of four one-bottle adhesives (OptiBond Solo Plus, Gluma Comfort Bond, One Step and Prime & Bond NT) and a multi-step adhesive (Clearfil Photo Bond) as a control was evaluated. The dentine cavity wall was conditioned with phosphoric acid or ethylenediaminetetraacetic acid (EDTA) and the marginal integrity was estimated by measuring the wall-to-wall contraction gap width between the composite and the dentine cavity surface. In the positive control group, the adhesive was applied following glyceryl methacrylate (GM) priming. The analyses were performed by Kruskal-Wallis and Mann-Whitney U-tests. One-bottle adhesives were clearly inferior to the multi-step bonding system in marginal integrity when dentine was conditioned with EDTA. The present findings also suggested that the marginal sealing ability of ethanol-based one-bottle systems was better than acetone-based one-bottle systems when dentine surfaces were conditioned with EDTA. Nevertheless, further investigations are needed on the function of fillers in one-bottle adhesives for the prevention of contraction gaps.

Overestimating hybrid layer quality in polished adhesive/dentin interfaces.

The most popular techniques for determining the quality of the hybrid layer (HL) have relied on morphologic characterization of the polished adhesive/dentin (a/d) interfaces before and after acid-bleach chemical treatment. Using these techniques, the existence of smooth, acid-resistant layers has been consistently reported for most adhesive systems. The purpose of this study was to determine whether popular specimen preparation techniques that include polishing and acid-bleach treatment modify the a/d interface, mask the complexity of the HL, and lead to inaccurate assessment of the quality of the HL. To understand the impact of specimen preparation techniques on the morphology of the resin-dentin interface, polished and unpolished specimens from the same tooth were closely compared after different acid-bleach chemical treatment procedures. Two one-bottle adhesives, that is, 3M Single Bond and Pulpdent UNO, exhibiting distinct differences in hydrophilic/hydrophobic composition, were used in this investigation. Using specimens from the same tooth, the effect of chemical treatments on the morphology of the resin-dentin interdiffusion zone and the differences in the morphology of polished and unpolished specimens after these same treatments were studied with scanning electron microscopy. It was shown that conventional specimen preparation techniques that include polishing and acid-bleach treatment can adversely affect and even obscure the structural detail of the a/d interface in specimens that possess a porous HL. The results indicated that the Pulpdent UNO/dentin interface had better quality than the 3M Single Bond/dentin interface. The difference in the quality of HL can be attributed to factors such as compositional differences that impact the adhesive interaction with water, that is present within the substrate during wet bonding. The inability of the conventional acid-bleach procedure to reveal the differences in the scanning electron microscopy interfacial morphology was overcome in this investigation by using a multistep technique.

Dimensional changes and ultimate tensile strengths of wet decalcified dentin applied with one-bottle adhesives

Objectives: The objectives of this study were to test the null hypothesis that no dimensional changes in wet decalcified dentin matrices will occur during the application of one-bottle adhesives, and to evaluate the ultimate tensile strengths (UTS) of resin-infiltrated dentin matrices using the microtensile test. Methods: Dentin disks 0.2 mm thick were prepared from mid-coronal dentin of human unerupted third molars. They were completely decalcified in 0.5 M EDTA (pH 7.4) for 5 days at 25 °C and then placed in the bottom of an aluminum well to permit use of the LVDT portion of a thermal mechanical analyzer. Changes in matrix height in response to the application of Single Bond, One-Step or Prime & Bond NT were measured along with the UTS of resin-infiltrated specimens that were compared using a one-way ANOVA and Fisher's PLSD test. Results: All one-bottle adhesives produced a gradual, progressive shrinkage of the decalcified matrix of 26–33%. The shrinkage produced by Single Bond was significantly greater ( p<0.05) than that produced by the other adhesives. The UTS of One-Step was significantly higher (<0.05) than that of Prime & Bond NT (42.0±13.6 vs 29.7±1.9 MPa, respectively), with Single Bond producing intermediate UTS (34.3±7.4 MPa). Significance: If the durability of resin–dentin bonds depends upon the size of interfibrillar spaces for both diffusion channels and resin uptake, then adhesive formulations should be designed to minimize matrix shrinkage during resin infiltration.