Bond strengths of nonrinsing adhesives.

OBJECTIVE: The purpose of this study was to determine enamel and dentin bond strengths of a nonrinsing "all-in-one" adhesive and of a nonrinsing conditioner combined with a 1-bottle adhesive. METHOD AND MATERIALS: Specimens were obtained from 240 bovine teeth ground to expose enamel or dentin surfaces. Ten enamel and 10 dentin specimens were randomly assigned to each of 12 different combinations of adhesive system (Prompt L-Pop; no etch + Prime & Bond NT; NRC + Prime & Bond NT; 36% phosphoric acid + Prime & Bond NT; no etch + Prime & Bond 2.1; 36% phosphoric acid + Prime & Bond 2.1) and restorative material (resin composite; polyacid-modified resin composite ["compomer"]). After the application of the adhesive system, a No. 5 gelatin capsule filled with the restorative material was seated against the enamel or dentin surface. After 24 hours in distilled water at 37 degrees C, the specimens were thermocycled and the shear bond strengths were measured. RESULTS: For resin composite, etching with phosphoric acid resulted in the highest bond strengths to enamel. For compomer, the highest enamel bond strengths were achieved with both phosphoric acid and Prompt L-Pop. Treating dentin with Prime & Bond NT without etching provided the highest mean bond strength for composite. For compomer, treating dentin with Prime & Bond NT resulted in the highest mean bond strengths, regardless of the conditioner. CONCLUSION: Compomer and resin composite exhibited statistically similar bond strengths. Bond strengths to dentin were significantly lower than those to enamel.     

Tensile bond strength of different adhesive systems to enamel and dentin

The aim of this study was to assess the tensile bond strength of four adhesive systems to enamel and dentin: Clearfil Liner Bond 2V - C, Prime&Bond NT/NRC - PB, Single Bond - SB and All Bond 2 -AB. For such purpose, 40 sound human molars were selected. Crowns were bisected in a mesiodistal direction and each half was ground until flat enamel (E) or dentin (D) surfaces were obtained. A total of 80 specimens were randomly assigned to 4 groups (n=20, 10 in enamel and 10 in dentin). After surface treatment, a composite resin (Z250; 3M) cone was prepared using a split Teflon(R) matrix. Bond strength was tested in an universal testing machine (0.5 mm/min). Bond strength means in MPa were: C - E: 18.66 (+/-2.67) and D: 21.62 (+/-5.29); PB - E: 18.13 (+/-2.96) and D: 3.19 (+/-1.40); SB - E: 20.06 (+/-6.11) and D: 16.95 (+/-2.57); AB - E: 18.20 (+/-3.94) and D: 15.94 (+/-4.72). Statistical analysis of data by two-way ANOVA showed that C presented the best results followed by SB. In conclusion, among the tested materials, Clearfil Liner Bond 2V self-etching primer adhesive syetem had the best performance. The substrate type influenced bond strength, being higher to enamel.     

Influence of Er:YAG laser on tensile bond strength of a self-etching system and a flowable resin in different dentin depths

OBJECTIVE: The aim of this study was to evaluate the tensile resistance of a flowable resin in different dentin depths, after superficial treatment with Er:YAG laser. METHODS: Eighteen molars were selected and roots were removed. Crowns were bisected in half, embedded in polyester resin and ground until dentin was exposed. The bonding site was delimited and samples were randomly assigned into two groups: superficial dentin (SD--1 mm from amelodentinal junction) and deep dentin (DD--2 mm from amelodentinal junction). The samples were subdivided in three groups according to superficial treatment: non-rinsing conditioner (NRC) solely; Er:YAG laser (80 mJ/2 Hz)+NRC; Er:YAG laser solely. After conditioning, Prime and Bond NT/Dyract flow (Dentsply) was used for the manufacture of specimens. They were adapted to a metallic device, where resin cones were prepared. Samples were stored for 24 h and subjected to a bond strength test (50 kgf at 0.5 mm/min). RESULTS: Means in MPa were: SD-NRC solely 12.29 (+/-4.40); laser+NRC 12.11(+/-3.23); laser solely 5.74(+/-3.01) and DD-NRC solely 9.60 (+/-3.13); laser+NRC 10.44(+/-2.23); laser solely 3.50(+/-1.70). Data were submitted to statistical analysis by ANOVA and Scheffé test (p < 0.05). CONCLUSIONS: SD produced better results and tensile bond strength, while on DD the treatment with NRC or Laser+NRC had higher tensile bond strength. The results suggest that when Er:YAG laser for dentin treatment is used, it is mandatory to associate it to a conditioning agent.     

A comparison of microtensile bond strengths of several dentin bonding systems to primary and permanent dentin.

OBJECTIVES: Limited information exists with regard to the adhesive ability of glass ionomer cements (GIC) and recently developed resin-based dentin bond systems to primary dentin. The aim of this study was to compare the microtensile bond strength of a conventional GIC (Fuji IX), a resin-modified GIC (Fuji II LC), and two resin-based dentin adhesives (Prime and Bond NT with NRC and Single Bond). The bonded interfaces were also observed using field emission electron microscopy(FE-SEM). METHODS: Microtensile bond test specimens were prepared on superficial dentin of primary and permanent molars. The specimens were bonded according to each manufacturer's instructions except for Prime and Bond NT/NRC which used Silux Plus resin composite instead of Dyract. Hour-glass shaped specimens were created (diameter of 1.2+/-0.02 mm) and stressed in tension at a crosshead speed of 1mm/min. Results were analyzed using two-way ANOVA and LSD test, fracture modes were analyzed using the Mann-Whitney U-test and Kruskall-Wallis test. Twelve specimens were prepared for each material on primary and permanent dentin. Samples were prepared in the same manner, then critical point dried, fractured and sputter-coated for the FE-SEM observations. RESULTS: Two-way ANOVA showed the overall bond strengths were greater for the permanent dentin compared with primary dentin. However, for individual material comparisons no differences among the bond strengths to primary and permanent dentin for Fuji IX (9.7, 12.2 MPa), Fuji II LC (16, 20.1 MPa), Prime & Bond NT/NRC (18.1, 21.6 MPa) and Single Bond (18.2, 21.6 MPa), were detected. However, Fuji IX bond strengths were significantly lower than the other systems tested when bonded to either primary or permanent dentin (p<0.05). Failure mode showed cohesive failure of GIC and mostly adhesive failure for the resin-based adhesives. The FE-SEM observations showed hybrid-like layer formation for the GIC materials and hybrid layer formation for the resin-based adhesives. SIGNIFICANCE: The materials tested would be suitable for bonding to either primary or permanent dentin, but the resin-modified GIC or resin-based systems are likely to provide a stronger bond than the conventional GIC, Fuji IX.     

Comparative SEM evaluation of penetration of adhesive systems in human dentin with a non-rinse conditioner and a self-etching primer

The purpose of this study was to compare the effect of a self-etching primer and a non-rinse conditioner with the effect of a conventional adhesive system on the penetration depth in dentin of human teeth, using scanning electronic microscopy (SEM). Fifteen human third molar teeth were sectioned into 2 pieces. All pieces were flattened with grade 600 to 1200 silicon carbide paper and divided into 6 groups: group 1 - Prime & Bond NT (NT), negative control; group 2 - 37% phosphoric acid + Prime & Bond NT (PANT), positive control; group 3 - Non-rinse Conditioner (NRC) + Prime & Bond NT (NRCNT); group 4 - NRC + Prime & Bond 2.1 (NRCPB); group 5 - NRC + Scotchbond MP (NRCSB); group 6 - Prompt L-Pop (PLP). All teeth were covered with Dyract AP. The tooth fragments were decalcified, and its resin replicas were evaluated by SEM by three previously standardized examiners. The penetration was scored from 0 (no penetration) to 3 (maximum penetration). The Kruskal-Wallis and Mann-Whitney U tests (p<0.05) showed three statistically homogeneous groups: (NT, NRCPB, NRCSB and PLP), (NRCNT) and [PANT]. The authors concluded that the self-etching primer and the non-rinse conditioner provide a lower penetration depth in human tooth dentin than the conventional adhesive system.     

Shear bond strength of acetone-based one-bottle adhesive systems

The aim of this study was to assess the shear bond strength of four acetone-based one-bottle adhesive systems to enamel and dentin, and compare to that of an ethanol-based system used as control. Fifty human molars were bisected mesiodistally and the buccal and lingual surfaces were embedded in acrylic resin using PVC cylinders. The buccal surfaces were ground to obtain flat dentin surfaces, while the lingual surfaces were ground to obtain flat enamel surfaces. All specimens were polished up to 600-grit sandpapers and randomly assigned to 5 groups (n=20; 10 dentin specimens and 10 enamel specimens), according to the adhesive system used: One-Step (Bisco); Gluma One Bond (Heraeus Kulzer); Solobond M (Voco); TenureQuik w/F (Den-Mat) and OptiBond Solo Plus (Kerr) (control). Each adhesive system was applied according to the manufacturers' instructions. The respective proprietary hybrid composite was applied in a gelatin capsule (d=4.3 mm) and light-cured for 40 s. The specimens were tested in shear strength with an Instron machine at a crosshead speed of 5 mm/min. Bond strengths means were analyzed statistically by one-way ANOVA and Duncan's post-hoc (p< or =0.05). Shear bond strength means (MPa) (+/-SD) to enamel and dentin were: Enamel: One-Step=11.3(+/-4.9); Gluma One Bond=16.3(+/-10.1); Solobond M=18.9(+/-4.5); TenureQuik w/F=18.7(+/-4.5) and OptiBond Solo Plus=16.4(+/-3.9); Dentin: One-Step=6.4(+/-2.8); Gluma One Bond=3.0(+/-3.4); Solobond M=10.6(+/-4.9); TenureQuik w/F=7.8(+/-3.9) and OptiBond Solo Plus=15.1(+/-8.9). In enamel, the adhesive systems had statistically similar bond strengths to each other (p>0.05). However, the ethanol-based system (OptiBond Solo Plus) showed significantly higher bond strength to dentin than the acetone-based systems (p< or =0.0001). In conclusion, the solvent type (acetone or ethanol) had no influence on enamel bond strength, but had great influence on dentin bonding, which should be taken into account when choosing the adhesive system.     

Microtensile bond strengths of seven dentin adhesive systems.

OBJECTIVES: The purpose of this study was to evaluate the microtensile bond strengths of seven dentin adhesive systems (Solid Bond, EBS-Multi, PermaQuik, One Coat Bond, Gluma One Bond, Prime & Bond NT/NRC and Clearfil Liner Bond 2V) and their respective fracture modes. METHODS: Superficial occlusal dentin of extracted human molars was exposed, finished with wet 600-grit silicon carbide paper, and a block of resin composite bonded with the above adhesives according to the manufacturers' instructions. The teeth were kept in tap water for 24 h at 37 degrees C, sectioned to obtain three or four bar-shaped specimens, which were then shaped to an hour-glass form of 1.2 +/- 0.02 mm diameter. The specimens were stressed at a crosshead speed of 1 mm/min until rupture of the bond. The mean bond strengths were compared using one-way ANOVA and LSD tests. The frequency of fracture modes was compared using Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: Mean microtensile bond strengths ranged from (17.8 +/- 7.0) MPa for Solid Bond to (36.0 +/- 8.1) MPa for Clearfil Liner Bond 2V. The bond strength of Clearfil Liner Bond 2V and PermaQuik (30.8 +/- 8.5 MPa) were not significantly different, and were higher than all other materials. Bond strengths of Solid Bond (17.8 +/- 7.0) MPa, EBS-Multi (18.7 +/- 5.0) MPa, One Coat Bond (21.9 +/- 5.6) MPa, and Gluma One Bond (23.4 +/- 5.2) MPa were not significantly different. SEM examination indicated that Solid Bond, EBS-Multi and One Coat Bond showed no significant difference in failure modes but were significantly different from PermaQuik, Prime & Bond NT/NRC and Clearfil Liner Bond 2V. SIGNIFICANCE: The self-etching primer system, Clearfil Liner Bond 2V, provided the simplest bonding technique, and together with PermaQuik exhibited greatest bond strength to dentin.     

Performance and Compatibility of Self Polymerizing Prime and Bond NT Adhesive and the Composite LuxaCore]

AIM: To evaluate the performance of bond strength and the compatibility of Prime &Bond NT self etching adhesive resins without activator on dentin surface with dual composite resin LuxaCore, and verify the contribution of a coactivator. MATERIAL AND METHODS: twenty-four human teeth without decay, molars or pre-molar are used. The dental crowning is cut with diamond disc mounted on a hand piece; the roof surface is flattened and well humidified. Each tooth is embedded in cold self-etching resin (Plexil Excil). Samples are divided into two groups of 12. in the first group, self-etching Prime &Bond NT resin adhesive without activator is supplied on the flat mesial dentin roots, then dual cure composite resin LuxaCore) is bonded. The second group was subject to the same treatment but with addition of co-activator the Prime &Bond NT self-etching adhesive resin. Debonding was achieved with Universal testing machine and mean shear bond strengths were determined for each test group. The data were subjected to ANOVA (p < 0001). RESULT: Bond strength obtained with self-etching Prime &Bond NT without activator is 10.635 MPa. With addition of activator it is 15.185 MPa CONCLUSION: supplementing with an activator has significantly improved bonding strength.     

Bond strength of self-etching primers to enamel and dentin of primary teeth.

PURPOSE: The objective of this in vitro study was to evaluate the tensile bond strength of three self-etching primers to human primary enamel and dentin. METHODS: Forty (40) freshly extracted primary molars were sectioned bucco-lingually and embedded in self-curing acrylic resin with the facial or lingual surfaces exposed. The specimens were wet ground to 600 grit SiC paper to expose a flat enamel or dentin surface. The materials tested were: Prompt L-Pop (LP2, ESPE), Clearfil SE Bond (CSE, Kuraray America), Etch and Prime 3.0 (EP, Degussa) anda control, Prime and Bond NT (NT, Dentsply/Caulk). The adhesive systems were applied according to the manufacturers' instructions. An inverted, truncated cone of composite (Pertac II, ESPE) with a 2-mm bonding diameter was cured using a polytetrafluoroethylene jig. The specimens were debonded in tension using a universal testing machine (Instron) at a crosshead speed of 0.5 mm/min. RESULTS: Analysis of variance (ANOVA) showed significant differences existed between the four systems and two surfaces. To enamel of primary teeth, Prime and Bond NT had significantly higher bond strength (25.9 MPa) than when bonding with the three acidic primers Prompt L-Pop (18.5 MPa), Etch and Prime 3.0 (19.3 MPa) and Clearfil SE Bond (18.7 MPa). Complete bond failures occurred with Prompt L-Pop and Etch and Prime 3.0 to dentin of primary teeth. With a mean of 39 Mpa, the bond strength to dentin of primary teeth with Clearfil SE Bond was significantly higher than with Prime and Bond NT (12.5 MPa). CONCLUSIONS: The results of this in vitro study show that the four adhesive systems tested bonded effectively to enamel of primary teeth, but only CSE achieved adequate bond strengths to dentin of primary teeth.     

Bonding to enamel and dentin using self-etching adhesive systems.

OBJECTIVES: This study investigated the effectiveness of three different dentin adhesive systems on the adhesion of resin composite to both dentin and enamel. METHOD AND MATERIALS: The flat dentin and enamel surfaces of 60 extracted human molar teeth were exposed by wet grinding with 600-grit silicon carbide paper. One total-etch self-priming adhesive system (Prime & Bond NT), one two-step self-etching primer adhesive system (Clearfil SE Bond), and one "all-in-one" self-etching adhesive system (Prompt L-Pop) were evaluated. Each bonding system was applied according to the manufacturer's instructions and followed by composite (TPH Spectrum) application. Twenty-four hours after bonding, the teeth were subjected to shear testing. There were 10 replicates for each group. RESULTS: Prompt L-Pop exhibited significantly higher bond strength values to enamel (27 +/- 4.2 MPa) than all other groups. There were no statistically significant differences for shear bond strength to dentin among adhesives. Prompt L-Pop showed the statistically significantly higher bond strength to enamel than dentin. There were no statistically significant differences between the enamel and dentin bond strengths of Clearfil SE Bond and Prime & Bond NT. CONCLUSIONS: The self-etching adhesive systems produced high bond strengths to human coronal dentin and ground enamel surfaces. These materials seem to be very promising for further clinical applications, and the results are very encouraging for the clinical success of these simplified adhesive systems. The self-etching adhesive systems produced even better bond strengths to both enamel and dentin than conventional total-etch systems, especially the "all-in-one" system, which produced the highest bond strength to enamel.     

Laboratory evaluation and clinical application of a new one-bottle adhesive.

PURPOSE: The purposes of this project were to compare the enamel and dentin bond strengths of a new nanofilled one-coat adhesive system with its predecessor, an unfilled two-coat adhesive system; to analyze the dentin interfacial ultramorphology, using scanning and transmission electron microscopy (SEM and TEM); and to illustrate the clinical technique associated with the use of the new nanofilled one-coat adhesive system. MATERIAL AND METHODS: Twenty flat dentin surfaces and 20 flat enamel surfaces were polished on the labial surface of bovine incisors mounted in acrylic resin. The specimens were equally and randomly assigned to four bonding groups: (1) dentin with Prime & Bond 2.1; (2) dentin with Prime & Bond NT; (3) enamel with Prime & Bond 2.1; and (4) enamel with Prime & Bond NT. A composite post was then adapted to the treated area and light-cured. After thermocycling, shear bond strengths were determined by testing the shear strength of the specimens. The data were analyzed using one-way analysis of variance (ANOVA) and Student's t-test. For SEM and TEM, six dentin disks were obtained from middle dentin of human third molars and assigned equally to each adhesive. The adhesives were applied to dentin according to manufacturer's directions. The hybrid layer and resin penetration into dentin tubules were analyzed at an ultramorphologic level, and the observations were compared. RESULTS: Shear bond strengths were as follows: group 1: 17.8 +/- 4.1 MPa; group 2: 20.5 +/- 3.5 MPa; group 3: 24.7 +/- 6.7 MPa; and group 4; 27.0 +/- 5.4 MPa. Electron microscopy showed that both adhesives penetrated the dentin tubules and formed a fully infiltrated hybrid layer. The nanofiller included in the new one-application adhesive penetrated the dentin tubules and infiltrated the microspaces between the collagen fibers within the hybrid layer. CLINICAL SIGNIFICANCE: The new one-application nanofilled adhesive tested in this study resulted in bond strengths and dentin hybridization comparable to those obtained with the corresponding two-application system. The clinical sequences presented illustrate the ease of use of the newest simplified adhesives.     

Effects of adhesive liner and provisional cement on the bond strength of nickel/chrome/beryllium alloy cemented to dentin.

OBJECTIVE: Treating teeth with adhesive agents before placing a provisional restoration can prevent tooth sensitivity. This study evaluated the bond strength of resin cements to dentin treated with 2 adhesive agents and 2 provisional cements. METHODS AND MATERIALS: Extracted human molars were prepared by exposing dentin and were treated with either Prime & Bond NT or Clearfil SE Bond. After a simulated impression technique, the teeth were provisionalized with either a eugenol or noneugenol temporary cement. Teeth were cleaned for bonding by either mechanical removal of the cement or use of an acid conditioner. Panavia F and Calibra resin cements were used to cement nickel/chrome/beryllium alloy to the tooth surfaces, and the specimens were debonded. Mean shear bond strengths for each group were calculated. RESULTS: Mean shear bond strengths ranged from 26.6 +/- 5.8 MPa for Calibra bonded to dentin treated with Prime & Bond NT, a noneugenol cement, and mechanically cleaned, to 10.6 +/- 4.4 MPa for Panavia F bonded to unlined (no adhesive) dentin treated with a eugenol cement and mechanically cleaned. Of the 14 groups tested, significant differences were observed related to the adhesives and resin cements. Both temporary cements reduced the bond to dentin not treated with a resin adhesive. Use of an acid conditioner for cleaning the temporary cement also reduced bond strengths in all groups. CONCLUSIONS: Placement of a dentin adhesive before provisionalization may prevent the temporary cement from affecting the bond of the final resin cement to the tooth. For the products used in this study, use of phosphoric acid to clean the tooth surface is not recommended.     

Nanoleakage patterns of four dentin bonding systems.

OBJECTIVES: The purpose of this study was to evaluate the nanoleakage patterns of four dentin bonding systems. METHODS: The dentin bonding systems used in this study were: Single Bond, One Coat Bond, Prime & Bond NT/Non Rinse Conditioner (NRC), and PermaQuik. Flat occlusal dentin surfaces from extracted human molars were finished with wet 600-grit silicon carbide paper, and bonded with one of the dentin bonding systems. After 24 h storage at 37 degrees C in water, margins were finished with polishing discs and the surrounding tooth surfaces coated with nail varnish. The samples were immersed in a 50% (w/v) solution of silver nitrate for 24 h, and exposed to photodeveloping solution for 8 h. The samples were cut longitudinally, polished, and mounted on stubs, carbon coated and observed in a Field Emission-SEM using backscattered electron mode. RESULTS: Different nanoleakage patterns were observed with the different adhesive systems. However, accumulations of silver particles were often noted at the base of the hybrid layer for all materials. Single Bond and One Coat Bond demonstrated uptake of silver particles both within the hybrid layer and the adhesive resin. Prime & Bond NT/NRC showed silver staining throughout almost the entire thickness of the hybrid layer. The leakage pattern of PermaQuik revealed loose silver deposition within the hybrid layer. The composition of each adhesive system may play a role in forming the different leakage patterns. SIGNIFICANCE: The current dentin bonding systems used in this study do not achieve perfect sealing at the restoration/dentin interface, which may influence the durability of the bond to dentin.     

Laboratory Evaluation and Clinical Application of a New One-Bottle Adhesive

Abstract: Purpose: The purposes of this project were to compare the enamel and dentin bond strengths of a new nanofilled one-coat adhesive system with its predecessor, an unfilled two-coat adhesive system; to analyze the dentin interfacial ultramorphology, using scanning and transmission electron microscopy (SEM and TEM); and to illustrate the clinical technique associated with the use of the new nanofilled one-coat adhesive system.
Material and Methods: Twenty flat dentin surfaces and 20 flat enamel surfaces were polished on the labial surface of bovine incisors mounted in acrylic resin. The specimens were equally and randomly assigned to four bonding groups: (1) dentin with Prime & Bond 2.1; (2) dentin with Prime & Bond NT; (3) enamel with Prime & Bond 2.1; and (4) enamel with Prime & Bond NT. A composite post was then adapted to the treated area and light-cured. After thermocycling, shear bond strengths were determined by testing the shear strength of the specimens. The data were analyzed using one-way analysis of variance (ANOVA) and Student's t-test. For SEM and TEM, six dentin disks were obtained from middle dentin of human third molars and assigned equally to each adhesive. The adhesives were applied to dentin according to manufacturer's directions. The hybrid layer and resin penetration into dentin tubules were analyzed at an ultramorphologic level, and the observations were compared.
Results: Shear bond strengths were as follows: group 1: 17.8 + 4.1 MPa; group 2: 20.5 + 3.5 MPa; group 3: 24.7 + 6.7 MPa; and group 4: 27.0 + 5.4 MPa. Electron microscopy showed that both adhesives penetrated the dentin tubules and formed a fully infiltrated hybrid layer. The nanofiller included in the new one-application adhesive penetrated the dentin tubules and infiltrated the microspaces between the collagen fibers within the hybrid layer.     

Bond strengths of nine current dentine adhesive systems to primary and permanent teeth

The aim of this study was to compare the shear bond strength (SBS) of nine dentine bonding systems (DBS) of different classes to human primary and permanent dentine. Flat dentine occlusal surfaces were produced on human molars (100 primary, 100 permanent) by wet grinding on a 800-grit SiC paper. Nine DBS were applied following the manufacturers' instructions: One total etch multi-step system: Scotchbond Multipurpose Plus (3M/ESPE); Four total etch one-bottle system: Prime &Bond 2.1 (Dentsply), One Step (Bisco), Scotchbond 1 (3M/ESPE), and OptibondSolo Plus (Kerr); Three two-step self-etching primer systems: Clearfil Liner Bond 2 (Kuraray), Clearfil SE Bond (Kuraray), and Prime &Bond NT with NRC (Dentsply); An 'all-in-one' self-etching system: Prompt L-Pop (3M/ESPE). Composite (Z100; 3M/ESPE) cylinders (2 mm diameter, 3 mm high) were polymerized on the treated dentine surfaces and the specimens were stored at 37 degrees C for 24 h prior to testing. Twenty experimental groups were produced and tested. Statistical analysis revealed both a substrate and a bonding system effect. Two adhesive systems (One Step, Prime &Bond NT) had significantly higher bond strengths on permanent than on primary dentine. There was an effect of dentine bonding system on the mode of fracture. Although eight of the 10 DBS tested exhibited higher median SBS values on permanent dentine than on primary dentine, the dependent pairwise comparison identified a significant difference only for two groups. The use of simplified bonding systems does not necessarily result in improved bond strength to primary or to permanent dentine.     

Effect of solvent and rewetting time on dentin adhesion.

OBJECTIVE: The purpose of this in vitro study was to determine the influence of solvent and rewetting time on microtensile dentin bond strengths of four dentin adhesives. METHOD AND MATERIALS: Sixty human molar specimens were divided into four dentin adhesive treatment groups: (1) a water-based total-etch dentin adhesive, EBS Multi; (2) an ethanol-based total-etch adhesive, Excite; (3) an acetone-based total-etch adhesive, Prime & Bond NT; and (4) an ethanol- and water-based total-etch adhesive, Single Bond. For each dentin adhesive, three specimens were assigned to five dentin moisture conditions. Specimens were tested in the tensile mode. RESULTS: When adhesives were applied to moist dentin, bond strengths varied from 26.2 MPa for Prime & Bond NT to 29.5 MPa for Single Bond without any statistical differences. When applied to dentin that had been dried for 15 seconds, Prime & Bond NT and Excite resulted in the lowest mean bond strengths, but they were statistically similar to each other (7.9 and 8.3 MPa, respectively). Single Bond resulted in a mean bond strength of 12.7 MPa, which was significantly lower than that of EBS Multi (24.1 MPa). For the latter, all mean bond strengths were statistically similar when some amount of moisture was present on the surface. For the other three adhesives, mean bond strengths returned to the range obtained on moist dentin only when dentin was rewet for 30 seconds. CONCLUSION: Bond strengths upon rewetting depend on the type of solvent in the bonding system, and rewetting time.     

Influence of light-activated and auto- and dual-polymerizing adhesive systems on bond strength of indirect composite resin to dentin

STATEMENT OF PROBLEM: Clinicians must be aware of the bonding effectiveness of auto- and dual- polymerizing adhesive systems before choosing the material and technique of cementing inlay/onlays to dentin. An inadequate choice may compromise the success of indirect restorations. PURPOSE: This study compared the microtensile bond strength (MTBS) of indirect composite resin bonded to dentin by light-activated, autopolymerizing, and dual-polymerizing adhesive systems. MATERIAL AND METHODS: Occlusal dentin surfaces of 36 human third molars were exposed and flattened. Teeth were assigned to 1 of the following 6 groups (n=6) of adhesive luting systems: 2 dual-polymerizing systems (Scotchbond Multipurpose Plus/Rely X [SBMP] and Prime & Bond NT Dual Cure/Enforce [PBDC]); 1 autopolymerizing system (ED Primer/Panavia F [EDP]); and 3 light-activated systems (control groups) (Adper Single Bond/Rely X [SB], Prime & Bond NT/Enforce [PB], and Clearfil SE Bond/Panavia F [CF]). The restorative materials were applied according to manufacturer's directions. A 2-mm-thick prepolymerized composite resin (Clearfil APX) disc was cemented with the resin cements on the bonded dentin. Teeth were stored in water at 37 degrees C for 24 hours. Afterwards, teeth were sectioned both mesial-distally and buccal-lingually to obtain multiple bonded beam specimens with 0.8 mm(2) of cross-sectional area. Each specimen was tested in tension at a crosshead speed of 0.5 mm/min until failure. Data (MPa) were analyzed by 1-way analysis of variance and the Tukey post hoc test (alpha=.05). Failure patterns of tested specimens were analyzed using scanning electron microscopy. RESULTS: Mean MTBS values (MPa) for experimental groups were as follows: SBMP, 32.89 +/- 3.26(a); SB, 26.74 +/- 7.45(ab); PB, 26.11 +/- 4.48(ab); CF, 25.30 +/- 6.42(ab); EDP, 16.82 +/- 5.53(bc); PBDC, 11.20 +/- 5.89(c) (P<.001). Groups with similar lowercase letters were not significantly different. Failure pattern of fractured specimens varied according to the polymerization mode. CONCLUSION: The autopolymerizing system and one of the dual-polymerizing systems were as effective as the light-activated systems in bonding indirect composite restorations to dentin.     

SEM evaluation of a non-rinse conditioner and a self-etching adhesive regarding enamel penetration

This study evaluated the effect of a non-rinse conditioner (NRC) associated with two adhesive systems, Prime & Bond NT and Prime & Bond 2.1. The study also evaluated a self-etching adhesive, comparing it with the 37% phosphoric acid effects related to the regularity and infiltration depth of adhesives in human tooth enamel via observation using Scanning Electronic Microscopy (SEM). Fifteen third molars were longitudinally sectioned into four parts by means of a mesio-distal cut and facio-lingual cut. All pieces were flattened with silicon carbide paper, randomly separated and divided into five groups where the enamel surfaces were treated with different materials according to the manufacturers' instructions as follows: Group 1-Prime & Bond NT (Dentsply); Group 2-37% phosphoric acid + Prime & Bond NT; Group 3-Non-Rinse Conditioner (Dentsply) + Prime & Bond NT; Group 4-NRC + Prime & Bond 2.1 (Dentsply); Group 5-Prompt L-Pop (3M ESPE). All teeth were covered with Dyract AP (Dentsply). Specimens were decalcified, metalized and the inner portions of Dyract were observed in SEM and evaluated by calibrated examiners to evaluate resin penetration on enamel. Resin penetration was ranked from 0 = no penetration, to 3 = maximum penetration. The Kruskal-Wallis and Mann-Whitney U tests (p<0.05) showed only three statistically homogeneous groups: {1}, {2,3} and {4,5}. The authors concluded that Prime & Bond NT showed the lowest penetration, NRC showed similar effects compared to phosphoric acid when associated with Prime & Bond NT, and concluded that Prompt L-Pop showed similar effects to NRC, which was associated with Prime & Bond 2.1.     

Effect of blood contamination on the shear bond strength at resin/dentin interface in primary teeth

PURPOSE: To assess in vitro the shear bond strength at the resin/dentin interface in primary teeth after contamination with fresh human blood. METHODS: 75 crowns of primary molars were embedded in acrylic resin and mechanically ground to expose a flat dentin surface. The specimens were randomly assigned to five groups (n=15), according to the surface treatment. Group 1 (control) had no blood contamination. The other groups were blood-contaminated and subjected to different post-contamination protocols: in Group 2, the surfaces were rinsed with water; in Group 3, the surfaces were air-dried; in Group 4, the surfaces were rinsed and air-dried; and in Group 5, no post-contamination treatment was done. In all groups, a 3-mm dentin bonding site was demarcated, Single Bond adhesive system was applied and resin composite cylinders were bonded. After 24 hours in distilled water, shear bond strength was tested at a crosshead speed of 0.5 mm/minute. RESULTS: Means (in MPa) were: Group 1: 7.1 (+/- 4.2); Group 2: 4.0 (+/- 1.8); Group 3: 0.9 (+/- 0.7); Group 4: 3.9 (+/- 2.2) and Group 5: 1.3 (+/- 1.5). Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. Groups 2 and 4 were similar to each other (P > 0.05) and both ware similar to Group 1 (P > 0.05). These groups (2, 3 and 4) had statistically significantly higher bond strengths than Groups 3 and 5 (P < 0.05). Blood contamination negatively affected the shear bond strength to primary tooth dentin. Among the blood-contaminated groups, water-rinsed specimens had higher bond strengths than those that were exclusively air-dried or not submitted to any post-contamination protocol before adhesive application.     

Bond strength of self-etching primer and total-etch adhesive systems to primary dentin

PURPOSE: The objective of this study was to assess in vitro the tensile bond strength of a self-etching and 2 total-etch, single-bottle adhesive systems to primary dentin. METHODS: Thirty-six sound primary canine buccal surfaces were randomly assigned to 3 groups (N = 12), corresponding to the tested adhesive systems: (1) group I = Excite (EX); (2) group II = Single Bond (SB); and (3) group III = Prompt L-Pop (PLP). After 24-hour storage in distilled water, tensile bond strength was tested for failure at a crosshead speed of 0.5 mm/min. RESULTS: Means (MPa) and standard deviation (+/-) were: (1) EX = 12.72 (+/- .89); (2) SB = 10.86 (+/- 2.09); (3) PLP = 8.66 (+/- 2.23). Single Bond and Excite showed statistically similar results (P >.05) and provided the highest means. Prompt L-Pop was statistically different from the other groups (P < .05) and reached the lower bond strength to primary dentin. CONCLUSIONS: Total-etch agents provided the best overall bonding performance, whereas the all-in-one, self-etching, self-priming adhesive system yielded remarkably lower bond strength to primary teeth dentin.