Rinse Adhesives Research Articles

The influence of neutral MDP-Na salt on dentin bond performance and remineralization potential of etch-&-rinse adhesive

ObjectivesTo investigate the effect of neutral 10-methacryloyloxydecyl dihydrogen phosphate salt (MDP-Na) on the dentin bond strength and remineralization potential of etch-&-rinse adhesive.MethodsTwo experimental etch-&-rinse adhesives were formulated by incorporating 0 wt% (E0) or 20 wt% (E20) neutral MDP-Na into a basic primer. A commercial adhesive, Adper Single Bond 2 (SB, 3 M ESPE), served as the control. Sixty prepared teeth were randomly allocated into three groups (n = 20) and bonded using either one of the experimental adhesives or SB. Following 24 h of water storage, the bonded specimens were sectioned into resin-dentin sticks, with four resin-dentin sticks obtained from each tooth for microtensile bond strength (MTBS) test. Half of the sticks from each group were immediately subjected to tensile loading using a microtensile tester at a crosshead speed of 1 mm/min, while the other half underwent tensile loading after 6-month incubation in artificial saliva (AS). The degree of conversion (DC) of both the control and experimental adhesives (n = 6 in each group) and the adsorption properties of MDP-Na on the dentin organic matrix (n = 5 in each group) were determined using Fourier-transform infrared spectrometry. Furthermore, the effectiveness of neutral MDP-Na in promoting the mineralization of two-dimensional collagen fibrils and the adhesive-dentin interface was explored using transmission electron microscopy and selected-area electron diffraction. Two- and one-way ANOVA was employed to assess the impact of adhesive type and water storage on dentin bond strength and the DC (α = 0.05).ResultsThe addition of MDP-Na into the primer increased both the short- and long-term MTBS of the experimental adhesives (p = 0.00). No difference was noted in the DC between the control, E0 and E20 groups (p = 0.366). The MDP-Na remained absorbed on the demineralized dentin even after thorough rinsing. The intra- and extra-fibrillar mineralization of the two-dimensional collagen fibril and dentin bond hybrid layer was confirmed by transmission electron microscopy and selected-area electron diffraction when the primer was added with MDP-Na.ConclusionsThe use of neutral MDP-Na results in high-quality hybrid layer that increase the dentin bond strength of etch-&-rinse adhesive and provides the adhesive with remineralizing capability. This approach may represent a suitable bonding strategy for improving the dentin bond strength and durability of etch-&-rinse adhesive.

Impact of economic factors and knowledge translation on public procurement for dental adhesive systems.

This study aimed to screen the public procurement for dental adhesives in a public health system and evaluate the variables associated with the type and cost of purchased materials. A time series was conducted with secondary data collated from the Brazilian Databank of Healthcare Prices (BDHP). All public procurements for adhesive systems registered from 2010 to 2019 were collated. The frequency of purchase was described, and a multiple linear regression model was used to assess the influence of unit price on predictor variables. Multinomial logistic regression was conducted to describe the influence of selected variables on the probability of purchase for different classes of adhesive systems. A total of 2,752 purchases were analyzed, and the total cost of these materials reached US$ 7,022,659.00 in the 10 analyzed years. The 3-step Etch & Rinse adhesives corresponded to 45.63% of the processes, with increased probability of being purchased over time. The process conducted by public universities in recent years, using the auction modality, presented lower unit prices. The year of purchase, the type of institutions, the institution's location, and the procurement modality influenced the procurement process. The performed analyses contribute to the understanding of the variables associated with the procurements for adhesive systems, providing valuable information for rationalizing public expenditure and for implementing evidence-based practices to guarantee cost-effective and clinically effective procedures for users of the Brazilian public healthcare system.

Six-year Clinical Performance of a 2-step Self-etch Adhesive in Noncarious Cervical Lesions.

Mild and intermediately strong 2-step self-etch adhesives (2SEa) have been shown to bond efficiently to dentin. In general, their bonding efficiency to enamel is inferior to that of etch & rinse adhesives (E&Ra). On the other hand, their application procedure is less elaborate, and consequently leaves less room for application mistakes. The aim of this randomized controlled trial was to evaluate the clinical performance of an intermediately strong 2SEa, as compared with that of a 3-step E&Ra after 6 years of clinical functioning. 239 non-carious cervical lesions in 50 patients were restored with the nanohybrid composite Herculite XRV (Kerr), bonded in random order either with the 2SEa Optibond XTR ('O-XTR', Kerr) or the gold-standard control 3E&Ra Optibond FL ('O-FL', Kerr). The restorations were recalled after 1, 2 and 6 years of clinical service and examined for retention, marginal adaptation, marginal discoloration, caries occurrence, and postoperative sensitivity. Statistical analysis was performed using a logistic regression model with generalized estimating equations (2-way GEE model). The patient recall rate at 6 years was 94%. The overall clinical success rate was 81.9% and 80.9% for O-XTR and O-FL, respectively. In total, 42 restorations (21 O-XTR, 21 O-FL) failed because of retention loss, severe abfraction/abrasion/erosion, severe marginal defects and/or discoloration, and/or caries. A retention rate of 92.9% and 88.9% was recorded for O-XTR and O-FL, respectively. Progressive marginal deterioration was observed over the 6-year period. Small clinically acceptable marginal defects were recorded in about 70% of the restorations (O-XTR: 69.9%; O-FL: 74.1%). Regarding marginal discoloration, 37% of the O-XTR and 30.2% of the O-FL restorations showed superficial clinically acceptable marginal discoloration. Six O-XTR and 4 O-FL restorations exhibited caries at the restoration margin. No significant difference was observed between the two groups for any of the evaluated parameters (p > 0.05). After 6 years of clinical service, Class-V restorations bonded with the 2SEa performed clinically equally well as those bonded with the 3E&Ra.

The clinical effectiveness of adhesive agents in posterior restorations

The clinical effectiveness of adhesive agents has been mainly evaluated using class V restorations. Clinical studies evaluating adhesives in combination with posterior composites are scarce and of short-term periods. This paper is aimed to review the current literature on the clinical effectiveness of contemporary adhesives when used to restore posterior teeth (Class I and Class II). To conduct this review, Scopus, PubMed, and Google Scholar databases were used to search for peer-reviewed articles on the clinical performance of adhesive agents in posterior composite restorations. Search terms used included “adhesive agents,” “clinical evaluation,” “composite restorations,” “posterior teeth,” “self-etch adhesives,” “etch -and -rinse adhesives,” and “universal adhesives.” To enrich the results, reference mining of the articles that were identified was used to locate other papers. The process of cross-referencing continued until no new articles were identified. No limits were placed on the year of publication, but only articles in English were considered. The current review found that simplification in the adhesive technique so far seems to affect the clinical performance. There is a relative paucity of evidence relating to the performance of universal adhesive agents in posterior restorations. Further long-term clinical studies are needed to evaluate the clinical performance of adhesive agents.

Bond Strength Comparison of Orthodontic Bonding Systems: A Systematic Review

As a means of regular practice in orthodontics and aesthetic dentistry, resin based adhesive systems are being used exclusively. Keeping up with the ever-increasing demand for aesthetic dental treatment all over the world, newer and more improved adhesive systems have been developed. However, regarding the comparison as to which bonding system performs better in clinical perspective, there is lack of existing scientific review articles. In this review, we tend to explore the conventional etch and rinse bonding system and the self-etch primer bonding system. The different tests to assess and compare bond strength between these two types of adhesives from various bibliography are discussed. The results of shear bond strength test, adhesive remnant index (ARI), enamel-adhesive interface using scanning electron microscope (SEM) and the effect of saliva contamination and time are discussed. Interestingly, each system has its strengths and weaknesses. In shear bond strength, self-etch bonding systems clearly exhibits less strength than conventional bonding systems. Resin tags into enamel surface are shorter in self-etch primer adhesives which results from milder etching to enamel compared to the conventional aid-etch and rinse adhesives. Contrarily, the irreversible changes to enamel surface is more aggressive in conventional acid-etching which states that self-etching systems are better according to the principles of minimal intervention dentistry.
 Ban J Orthod & Dentofac Orthop, April 2017; Vol-7 (1-2), P.20-26

Influence of phototherapy on adhesive strength and microleakage of bleached enamel bonded to orthodontic brackets: An in-vitro study.

The aim of the present in-vitro study was to explore bleached enamel reversal with phototherapy (Er,Cr:YSGG) when using two dissimilar bonding system to bond brackets on microleakage and shear bond strength. Amongst one twenty samples, ninety samples were bleached using 35% hydrogen peroxide. After the bleaching procedure, the teeth were randomly divided into three groups according to surface conditioning treatment (n = 30 each). Group 1: treated with Er,Cr:YSGG (ECL) Group 2: 10% sodium ascorbate (SA) and Group 3: Bleached only (BO). Based on the type of adhesive, specimens were further classified into eight subgroups. In subgroup 1,2,3 and no treatment (NT) (n = 15) adhesive Transbond XT was applied on already etched surface and these subgroups were named as NT-TEP, BO-TEP, ECL-TEP and SA-TEP. Similarly, in subgroup 5,6,7 and NT specimens (n = 15) were conditioned with Transbond Plus self-etching primer and these subgroups were named as NT-SEP, BO-SEP, ECL-SEP and SA-SEP. Samples from each subgroup were exposed to increasing load for evaluation of shear bond strength. Microleakage among subgroups were tested by immersing samples in Methylene blue prior one day. Analysis of variance and Tukey multiple comparisons test was used to assess data. The maximum and minimum bond strength was observed in group NT-TEP [17.14(2.54)] and BO-SEP [6.14(0.215)] respectively. Samples conditioned with phototherapy ECL-TEP [16.14(1.231)] exhibited comparable bond strength to specimens conditioned with sodium ascorbate (SA-TEP) [16.72(1.298)]. Similarly, bond strength values of ECL-SEP [13.43(0.921)] and SA-SEP were comparable. The highest microleakage score was demonstrated in BO-SEP [83.21(38.21)] whereas, the lowest microleakage scores were displayed in NT-TEP [23.73(13.45)]. Er,Cr:YSGG phototherapy reversal on bleached enamel with etch and rinse adhesives has a potential to be used in clinical settings alternate to conventional sodium ascorbate when bonding orthodontic brackets.

Effect of Proteolytic Agents on Microleakage of Etch and Rinse Adhesive Systems

Objective: this study aimed to assess the effect of treatment of phosphoric acid etched dentin surface with 5% bromelain enzyme and Nd:YAG laser prior to the use of etch and rinse adhesive systems on microleakage margins of class V composite restorations. Materials and Methods: sixty sound premolar teeth were selected. Standard class V cavities were prepared in the buccal and lingual surfaces of each teeth. Preparation in that way 1 mm of the cavity was above and 1 mm of it was below the cementoenamel junction. The teeth were then randomly divided into three groups including 20 teeth(40cavities in each gorup). Two ethanol base etch and rinse system (Adper Single Bond and OptiBond Solo) was applied in each group. In the control group, cavities were etched with 37% phosphoric acid. Adper Single Bond was applied to 20 and OptiBond Solo was applied to the remaining 20 cavities and they were restored with Z250 composite (n=40). The same procedures were performed in bromelain and Nd:YAG laser groups with the difference that prior to the application of adhesive, aqueous 5% bromelain was applied in bromelain group while Nd:YAG laser was irradiated in laser group. All teeth were thermocycled and their apices were sealed with sticky wax. The tooth surfaces were coated with nail varnish except for 1 mm around the restoration margins, and the teeth were then immersed in fuchsine and sectioned by a diamond disc into mesial and distal halves. Marginal microleakage at both sides was determined and scored under a stereomicroscope at x40 magnification. Then data were analyzed using the Kruskal Wallis and Mann Whitney tests (α=0.05). Results: according the result of Mann Whitney test, Cervical margins showed significantly higher microleakage than the occlusal margins (P=0.000) but no significant difference was noted in microleakage of occlusal (P=0.362) or gingival (P=0.147) margins among the three groups by Kruskal Wallis test. Conclusion: in conclusion, application of proteolytic agents(5% bromelain solution and Nd:YAG laser) on acid-etched dentin surface prior to the application of adhesive has no significant effect on marginal microleakage of class V composite restorations.

Sodium hypochlorite effects on dentin bond strength and acid-base resistant zone formation by adhesive systems

Aim: To evaluate the effects of 10% NaOCl gel application on the dentin bond strengths and morphology of resin-dentin interfaces formed by three adhesives. Methods: Two etch-and-rinse adhesives (One-Step Plus, Bisco Inc. and Clearfil Photo Bond, Kuraray Noritake Dental) and one self-etch adhesive (Clearfil SE Bond, Kuraray Noritake Dental) were applied on dentin according to the manufacturers’ instructions or after the treatment with 10% NaOCl (ED-Gel, Kuraray Noritake Dental) for 60 s. For interfacial analysis, specimens were subjected to acid-base challenge and observed by SEM to identify the formation of the acid-base resistant zone (ABRZ). For microtensile bond strength, the same groups were investigated and the restored teeth were thermocycled (5,000 cycles) or not before testing. Bond strength data were subjected to two-way ANOVA and Tukey’s test (p<0.05). Results: NaOCl application affected the bond strengths for One-Step Plus and Clearfil Photo Bond. Thermocycling reduced the bond strengths for Clearfil Photo Bond and Clearfil SE Bond when used after NaOCl application and One-Step Plus when used as recommended by manufacturer. ABRZ was observed adjacent to the hybrid layer for self-etch primer. The etch-and-rinse systems showed external lesions after acid-base challenge and no ABRZ formation when applied according to manufacturer’s instructions. Conclusions:10% NaOCl changed the morphology of the bonding interfaces and its use with etch-&-rinse adhesives reduced the dentin bond strength. Formation of ABRZ was material-dependent and the interface morphologies were different among the tested materials.

Effect of ethanol wet bonding technique on the durability of resin- dentin bond with contemporary adhesive systems.

To evaluate the effect of ethanol wet bonding technique on the immediate and long term bond strength of simplified etch and rinse adhesive systems to dentin. 96 extracted human permanent molars were ground to expose the flat dentin surface. The teeth were divided into four groups (n=24) according to the adhesives used, either Tetric N Bond or Solobond M and bonding techniques i.e. water wet bonding or ethanol wet bonding (EWB). Composite cylinder was bonded to each specimen using the respective adhesive technique. Ten samples from each group were then tested immediately for shear bond strength evaluation and two samples for SEM analysis. The remaining samples (12) were tested after 6 month storage in distilled water. Upon immediate testing, there was no significant difference in the mean shear bond strength of the groups regardless of the bonding technique or adhesive used. The bond strength fell dramatically in the water wet bonded specimens after 6 months water storage, while the bond strength of both the adhesives was maintained when EWB technique was used. SEM observation revealed good interfacial adaptation in EWB groups even after six months. For both simplified etch and rinse adhesives used, ethanol wet bonding technique led to significant preservation of the resin dentin bond over 6 months.

Evaluation of thickness of hybrid layer and length of resin tags of three adhesives to the root canal dentin: An in vitro scanning electron microscopic study

Objectives: This present study was done to evaluate the resin-dentin interface of three adhesive systems used for bonding the root canal under scanning electron microscopic (SEM). Materials and Methods: Sixty single-rooted human maxillary anterior teeth were decoronated at the cementoenamel junction apical preparation done up to 60 no. K-file and obturated with cold lateral compaction of gutta-percha and resin sealer (AH Plus). The specimens were then randomly divided into four groups of 15 teeth each. Group I-Etch and rinse adhesive system Group II-Self-etch adhesive system Group III-Resin modified glass ionomer adhesive system Group IV-No adhesive system used (control). All the adhesive systems were light cured then fiber posts were luted with dual cure resin cement and the specimens were prepared for SEM examination at magnifications ×1500 and ×5000 at coronal, middle and apical thirds of root canal. Results: Statistical analysis was performed using one-way ANOVA followed by post-hoc Tukey's honestly significant difference test. Group I showed highly statistical significant difference when compared with other groups. Conclusion: Maximum thickness of hybrid layer and long resin tags were shown by etch and rinse adhesives followed by self-etch adhesives.

The Effects of Surface Pretreatment on the Microleakage of Resin-Modified Glass-Ionomer Cement Restorations

To evaluate the effect of different surface pretreatments on the marginal microleakage of Vitremer restorations. Class V cavities were prepared on the labial and lingual surfaces of extracted human third molar teeth. Cavities were randomly distributed into six groups according to surface treatment, as follows: Group NC (negative control): no surface treatment; Group VP (positive control): Vitremer Primer; Group PA: 32% phosphoric acid; Group PAA: 20% polyacrylic acid; Group PLP: self-etch adhesive (Prompt L Pop); Group PB: etch & rinse adhesive (Prime & Bond NT). All cavities were restored with Vitremer. Teeth were thermocycled, stained with 0.5% basic fuchsin dye and sectioned. Microleakage values were quantitatively assessed by linear measurement of dye penetration using image-analyzing software. Differences between occlusal and gingival microleakage values within groups were evaluated using paired t-tests, and differences among groups were analysed using one-way analysis of variance (ANOVA) and Tukey tests. There were statistically significant differences between the occlusal and gingival microleakage values for all groups (p < 0.05). Microleakage differed significantly among surface pretreatment groups (p < 0.001). The negative control and PLP groups showed similar microleakage values, but were significantly higher than other groups for both margins. Although there were no statistically significant differences between positive control and PA, PAA, PB groups, microleakage values of positive control group were smaller than all other experimental groups except for PB group. Vitremer restorations require surface pretreatment to prevent excessive microleakage. Pretreatment with etch & rinse adhesives and Vitremer Primer may reduce microleakage of Vitremer restorations.

Dentin infiltration ability of different classes of adhesive systems

This study evaluates the dentin infiltration ability of various types of adhesives and compares four classes of adhesive systems with regard to this property. The infiltration is determined quantitatively, characterized as tag length and ratio of infiltration, and qualitatively, characterized as homogeneity, regularity, and continuity of the resin tags. Flat dentin surfaces from 140 halves of caries-free molars were bonded with four classes of adhesive systems. The adhesives (n = 20) were labeled with rhodamine B isothiocyanate and applied on the occlusal dentin following the manufacturer's recommendations and were subsequently light cured, 20s. Then a 2-mm thick composite layer was applied and light cured, 20s. The specimens were stored in distilled water at 37°C, 24h. Two slices were sectioned mesio-distally from each sample and were investigated with a confocal laser scanning microscope. The measurements were done at 0.5, 1.5, and 2.5mm from the enamel-dentin junction. The data were analyzed by using analysis of variance and the general linear model. The class of adhesive, the composition, and the dentin position were significant factors affecting the investigated parameters. The use of etch and rinse adhesives in comparison to self-etch adhesives provided the formation of longer, more homogeneous, very regularly distributed but mostly fractured tags. A comparison of adhesives confirmed that etch and rinse systems remain better in bond infiltration. While the importance of tags formation on bonding is still controversially discussed, adhesive systems with a high ratio of infiltration might better protect the tooth against microorganism contamination.

Biomodification to dentin by a natural crosslinker improved the resin–dentin bonds

ObjectivesTransient collagen cross-linking treatment by proanthocyanidins (PA), a natural crosslinker, was proved to increase the cross-linking degree and ultimate tensile strength of demineralised dentin. The present study aimed to investigate whether transient pretreatment by PA-based preconditioner can improve the resin–dentin bonds of various etch and rinse adhesives. The influence of solvent type, PA concentration and treatment duration were examined. MethodsPA-based preconditioners were prepared by adding powdered grape seed extract, rich in PA, to various solvents at different concentrations. They were used on demineralised dentin before the application of the bonding agent. Bond strength, failure modes and degree of conversion were evaluated via microtensile testing, field emission scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. ResultsCollagen cross-linking treatment by PA-based preconditioners presented a concentration- and time-dependent increase in dentin bond strength even in reduced, clinically applicable treatment duration. PA preconditioning improved bond strength of the tested water/ethanol-based adhesive better than the water/acetone-based system. Mixed fracture was the most prevalent failure mode happened on the top of the hybrid layer in PA-pretreated specimens, whilst at the bottom in non-treated controls. The degree of conversion was not significantly affected by PA pretreatment. ConclusionsTransient PA preconditioning improved resin–dentin bonds without compromise on the curing behaviours of the tested adhesives.

Fourier transform infrared photoacoustic spectroscopy study of physicochemical interaction between human dentin and etch-&amp;-rinse adhesives in a simulated moist bond technique

The purpose of this study was to provide the physicochemical interactions at the interfaces between two commercial etch-&-rinse adhesives and human dentin in a simulated moist bond technique. Six dentin specimens were divided into two groups (n=3) according to the use of two different adhesive systems: (a) 2-hydroxyethylmethacrylate (HEMA) and 4-methacryloxyethyl trimellitate anhydrate (4-META), and (b) HEMA. The Fourier transform infrared photoacoustic spectroscopy was performed before and after dentin treatment with 37% phosphoric acid, with adhesive systems and also for the adhesive systems alone. Acid-conditioning resulted in a decalcification pattern. Adhesive treated spectra subtraction suggested the occurrence of chemical bonding to dentin expressed through modifications of the OH stretching peak (3340 cm(-1)) and symmetric CH stretching (2900 cm(-1)) for both adhesives spectra; a decrease of orthophosphate absorption band (1040 to 970 cm(-1)) for adhesive A and a better resolved complex band formation (1270 to 970 cm(-1)) for adhesive B were observed. These results suggested the occurrence of chemical bonding between sound human dentin and etch-&-rinse adhesives through a clinical typical condition.

An in vitro evaluation of leakage of two etch and rinse and two self-etch adhesives after thermocycling.

Our experiment evaluated the microleakage in resin composite restorations bonded to dental tissues with different adhesive systems. 40 class V cavities were prepared on the facial and lingual surfaces of each tooth with coronal margins in enamel and apical margins in cementum (root dentin). The teeth were restored with Z100 resin composite bonded with different adhesive systems: Scotchbond Multipurpose (SBMP), a 3-step Etch and Rinse adhesive, Adper Scotchbond 1 XT (SB1), a 2-step Etch and Rinse adhesive, AdheSE One (ADSE-1), a 1-step Self-Etch adhesive, and AdheSE (ADSE), a 2-step Self-Etch adhesive. Teeth were thermocycled and immersed in 50% silver nitrate solution. When both interfaces were considered, SBMP has exhibited significantly less microleakage than other adhesive systems (resp., for SB1, ADSE-1 and ADSE, P = 0.0007, P < 0.0001 and P < 0.0001). When enamel and dentin interfaces were evaluated separately, (1) for the Self-Etch adhesives, microleakage was found greater at enamel than at dentin interfaces (for ADSE, P = 0.024 and for ADSE-1, P < 0.0001); (2) for the Etch and Rinse adhesive systems, there was no significant difference between enamel and dentin interfaces; (3) SBMP was found significantly better than other adhesives both at enamel and dentin interfaces. In our experiment Etch and Rinse adhesives remain better than Self-Etch adhesives at enamel interface. In addition, there was no statistical difference between 1-step (ADSE-1) and 2-step (ADSE) Self-Etch adhesives.

Comparison of Chemical Aging and Water Immersion Time on Durability of Resin-Dentin Interface produced by an Etch-and-Rinse Adhesive

The aim of this study was to analyze and compare the influence of short-term NaOCl-storage and long-term water storage on the microtensile bond strength (µTBS) of etch-and-rinse adhesive system to human dentin. Thirty-six third human molars were randomly divided into 6 groups (n = 6) according to the aging protocol: G1 (water, 24 hours); G2 (water, 6 months); G3 (water, 12 months); G4 (10% sodium hypochlorite--NaOCl, 1 hour); G5 (10% NaOCl, 3 hours) and G6 (10% NaOCl, 5 hours). A two-step etch-and-rinse adhesive (Adper Single Bond 2) was applied according to the manufacturers' instructions. A composite (Filtek Z250) was applied in four horizontal increments and was individually cured. Specimens were cut following the microtensile test technique, submitted to the different aging protocols, and tested in tension. The fracture pattern was observed in a stereomicroscope (40* magnification) and in a scanning electron microscope. The µTBS data were analyzed by ANOVA and Tukey's test (α = 0.05). The effect of storage in 10% NaOCl for 1 or 3 hours was not significantly different from that of aging in distilled water (DW) for 6 or 12 months (p > 0.05). Beams immersed in DW for 24 hours and in 10% NaOCl for 5 hours showed the highest and lowest µTBS values respectively. The aging protocols negatively influenced dentin bond strength. Aging specimens in 10% NaOCl for 1 or 3 hours can be an alternative method for long-term water storage (6 or 12 months) bond strength studies. This aging protocol allows a quick achievement of longitudinal bond strength data, so that results are available to the professionals in this area while the materials are yet present at the dental market.

Bonding of adhesives to Er:YAG laser-treated dentin

The shear bond strength of adhesives applied to dentin was investigated after irradiation with an erbium-doped yttrium aluminum garnet (Er:YAG) laser. Superficial and deep dentin specimens from human molars were treated either with carbide bur or an Er:YAG laser. Two etch and rinse adhesives (Single Bond and XP Bond) and two self-etch adhesives (Prompt L-Pop and Xeno III) were employed to bond the composite. Shear bond strength (SBS) was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm/min. Failure patterns and modes were analyzed and evaluated using a stereomicroscope. In addition, samples were processed for Scanning Electron Microscopy SEM evaluation. A linear mixed model was used, and pairwise comparisons were made using the Bonferroni test. Results showed significant differences between the levels of dentin treatment (p=.01) in carbide bur-cut dentin and lased dentin, as well as significant interaction effects due to the depth of dentin and the bonding system used. The etch and rinse adhesives bonded less effectively with lased dentin than with carbide bur-cut dentin, while self-etch adhesives bonded equally well with lased and bur-cut superficial dentin but much less effectively with lased deep dentin than with bur-cut deep dentin. SEM revealed a predominantly adhesive failure mode in laser-ablated fractured specimens, while a mixed failure mode was apparent in the bur-cut fractured specimens. Cavities prepared by laser seem less receptive to adhesive procedures than conventional bur-cut cavities.

Bond Strength and Interfacial Ultramorphology of Current Adhesive Systems

This study evaluated the bond strength and ultramorphology of the resin-dentin interfaces produced by current dental adhesive systems. Nine dentin bonding agents were investigated. Restored teeth were vertically, serially sectioned to obtain bonded slices for interfacial TEM analysis or to produce bonded beams for the microtensile bond strength test. The one-step self-etching adhesives (Futurabond® NR and Hybrid Bond®) showed lower bond strength values than the three-step etch-&-rinse adhesive system All-Bond 3. Most bonding agents presented statistically similar mean bond strength values, which ranged from 41.3 ± 17.9 to 35.0 ± 5.3 MPa. The thickness of the hybrid layer varied according to the type of adhesive system used. While the etch and rinse adhesives with alcohol as organic solvent showed bond strength means higher than 40 MPa, the self-etching systems showed bond strength lower than 40 MPa. Resin-dentin interdifusion zone and resin tags were noted in all bonded interfaces.

Shear Bond Strength of Ormocer-Based Restorative Material Using Specific and Nonspecific Adhesive Systems

The aim of this study was to evaluate the shear bond strength of ormocer-based restorative material bonded to tooth structure using specific ormocer and nonspecific resin-based adhesives. Human molars were prepared to obtain flat buccal enamel surfaces and flat occlusal dentin surfaces. Admira bond, and Prime &amp; Bond NT, Excite, AdheSE, and Prompt-L-Pop were applied to the prepared enamel and dentin surfaces. Ormocer restorative material was inserted into a mold fixed onto the prepared tooth surfaces. The restorative material was applied and cured. The shear bond strength was measured using a universal testing machine. The highest bond strength was recorded for Admira bond. The non-specific adhesives (AdheSE and Prompt-L-Pop) were recorded the lowest bond strength. Etch &amp; Rinse (Prime &amp; Bond NT and Excite) adhesives were recorded an intermediate values. Admira bond usually showed cohesive failure in the material with enamel and cohesive and mixed failure with the dentin. Etch &amp; Rinse adhesives showed mixed failure with the enamel and, mixed and adhesive failures with the dentin. Self-etching adhesives commonly exhibited adhesive mode of failure. So, Etch &amp; Rinse, non-specific bonding agents can be used with Admira ormocer-based restorative material when the specific adhesive is depleted.

Effect of dentin location and long-term water storage on bonding effectiveness of dentin adhesives

Dentin is a variable substrate with properties that change considerable in a single surface. The purpose of this study was to evaluate the bonding effectiveness to these different dentin locations and evaluate these differences over time. After bonding procedures with five different adhesives, small micro-tensile bond strength (µTBS) beams were prepared and dichotomously divided in 'center' and 'periphery' dentin specimens. After 1 week, 3, 6 and 12 months of water storage the µTBS of specimens of each group was determined, enabling a paired study design. The bond strengths of both etch&rinse adhesives were insensitive to regional variability. For the two-step self-etch adhesives, a marked increase in bond strengths was observed with increasing amount of intertubular dentin. Regional variability did not affect the long-term bonding effectiveness for any of the adhesives tested. In conclusion, only for the mild self-etch adhesives, µTBS to 'periphery' dentin was higher than for the 'center' specimens.