Optibond Solo Research Articles

The Effect of Decalcified Root Surfaces on Dentinal Bond Strength

Microtensile bond strengths of current dentin adhesives to intact and decalcified root surfaces were evaluated. Two hundred and twenty-four extracted human incisors were divided into two groups as intact (IRD) and decalcified (DRD). The roots of DRD teeth were placed in a demineralization solution to produce artificial carious-like lesions. Root surfaces were slightly ground and treated with either Scotchbond Multi-Purpose (SMP), Adper Single Bond Plus (SBP), Adper Easy Bond (AEB), Scotchbond SE (SSE), Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), Clearfil Tri-S Bond (CTS), FL-Bond II (FLB), XP Bond (XPB), iBond (IB), AdheSE Bond (ASE), Optibond Solo Plus (OSP), Prelude Dental Adhesive (PDA), and G-Bond (GB). Composite build-ups were formed on the bonded surfaces. After thermocycling, hour-glass shaped specimens with an area of 1 mm2 at the bonded interface were subjected to microtensile testing. Resin–dentin interfaces were observed with SEM. Kruskal Wallis and Mann Whitney-U tests were used for statistical analysis. There was not significant difference between bond strengths to intact and decalcified dentin, with the exception of ASE and CSE, which had higher values to IRD (p < 0.05). SSE and CTS were the adhesives that showed higher bond strengths to DRD than to IRD, however the difference was not significant (p > 0.05). The self-etch adhesives performed better on both IRD and DRD surfaces than etch-and-rinse systems.

Randomized clinical trial of four adhesion strategies in posterior restorations-18-month results.

To evaluate the 18-month clinical performance of four adhesive strategies in posterior composite restorations placed in private practice. Upon approval by an institutional review board, 144 restorations were inserted in 45 subjects (average age = 32.6) to treat caries lesions or to replace existing restorations in vital molars and premolars. The adhesives OptiBond FL (three-step etch-and-rinse), OptiBond SOLO Plus (two-step etch-and-rinse), OptiBond XTR (two-step self-etch), and OptiBond All-in One (one-step self-etch) were applied as per manufacturer's (Kerr Co.) instructions followed by a nanofilled resin composite (Filtek Z350XT, 3M ESPE) under rubber dam isolation. Restorations were evaluated at baseline and at 18 months using United States Public Health Service (USPHS)-modified criteria and high-resolution digital photographs. Statistical analyses included the McNemar and the Mann-Whitney non-parametric tests (p < 0.05). A total of 137 restorations were evaluated after 18 months. The number of alfa ratings did not change significantly from baseline to 18 months for any of the adhesion strategies. When the 18-month evaluation criteria were pooled by pairs of adhesives, none of the adhesives resulted in a significantly different number of alfa ratings for any of the criteria compared with the other adhesives. Bonding strategy did not influence the clinical performance of posterior composite restorations under the clinical conditions used in this study. When used in ideal clinical conditions, the composition of current dentin adhesives may be more clinically relevant than their adhesion strategy.

The effect of the nanofilled adhesive systems on shear bond strength of all-ceramics to dentin

Aim: This study evaluated shear bond strength between three all-ceramic systems to dentin using six different adhesives, of which three of them contain nanofillers. Materials and Methods: Ceramic discs were prepared from each of Ceramco, IPS Empress 2 and Copran Zr. Different dentin surfaces were prepared with adhesives. Adper Single Bond Plus, Nano-bond, Prime & Bond NT (PB), Excite Bond, One Step Plus, Opti Bond Solo Plus were applied to the conditioned dentin surfaces. Ceramic discs were luted to the dentin with resin cement. All specimens were kept in water at 37°C for 1-week and thermal cycled for 500 cycles in 5°C and 55°C. Shearing test was conducted, and statistical analyses were performed using nonparametric tests (α = 0.05). Fractured surfaces of each specimen were inspected with Scanning Electron Microscope. Furthermore, distribution of nanofillers into the nanofilled adhesives was examined by transmission electron microscope. Results: Significant differences were observed in bond strength values of the adhesives (P < 0.05). For each ceramic, PB showed the highest bond strength values. Failure mode was cohesive in nanofilled adhesives resin and mixed failure for the others. Nanofillers were aggregated in some areas for each nanofilled adhesive. Ceramco showed the highest bond strength values while Copran Zr showed the lowest. Conclusion: Nanofilled adhesive systems would suggest for good clinical performance together with all-ceramics system. Furthermore, felspathic ceramics is better than the other all-ceramics systems.

Evaluation of flexural, diametral tensile, and shear bond strength of composite repairs.

Repairing composite restorations may be a more conservative treatment than replacing the entire restoration. The objective of this in vitro study was to determine the best repair method by measuring flexural, diametral tensile, and shear bond strength of repaired composites in which the surfaces were treated with chemical primers (Add & Bond or Silane Bond Enhancer), a bonding agent (Optibond Solo Plus [OBSP]), or mechanical retention with a bonding agent. Filtek Supreme Ultra shade B1B was placed in special molds to fabricate specimens that served to test the flexural, diametral tensile, or shear strength of the inherent resin substrate. The same molds were modified to make specimens for testing repair strength of the resin. Repairs were made immediately or after aging in deionized water at 37°C for seven days. All repair sites were finished with coarse Sof-Lex discs to simulate finishing new restorations or partially removing aged restorations. Repair surfaces were treated with one of the following: 1) phosphoric-acid etching and OBSP; 2) Add & Bond; 3) phosphoric-acid etching, Silane Bond Enhancer, and OBSP; or 4) quarter round bur, phosphoric-acid etching, and OBSP. Specimens were placed back in the original molds to fabricate specimens for diametral tensile or flexural testing or in an Ultradent jig to make specimens for shear bond testing. Composite resin in shade B5B was polymerized against the treated surfaces to make repairs. Two negative control groups for the three testing methods consisted of specimens in which repairs were made immediately or after aging without any surface treatments. Controls and experimental repairs were aged (water 37°C, 24 hours) before flexural, diametral tensile, or shear testing in an Instron Universal testing machine at a crosshead speed of 0.5 mm/min. Experimental flexural repair strengths ranged from 26.4% to 88.6% of the inherent substrate strength. Diametral tensile repair strengths ranged from 40% to 80% of the inherent substrate strength, and shear bond strength repairs ranged from 56% to 102%. Geometric means were statistically analyzed with two-way analysis of variance on their log-transformed values. Significant differences were determined using Tukey honestly significant difference (p<0.05). Depending on the mechanical property being tested, surface treatments produced different results. OBSP produced more consistent results than chemical primers.

Effects of solvent evaporation on water sorption/solubility and nanoleakage of adhesive systems

ObjectiveTo evaluate the influence of solvent evaporation in the kinetics of water diffusion (water sorption-WS, solubility-SL, and net water uptake) and nanoleakage of adhesive systems. Material and MethodsDisk-shaped specimens (5.0 mm in diameter x 0.8 mm in thickness) were produced (N=48) using the adhesives: Clearfil S3 Bond (CS3)/Kuraray, Clearfil SE Bond - control group (CSE)/Kuraray, Optibond Solo Plus (OS)/Kerr and Scotchbond Universal Adhesive (SBU)/3M ESPE. The solvents were either evaporated for 30 s or not evaporated (N=24/per group), and then photoactivated for 80 s (550 mW/cm2). After desiccation, the specimens were weighed and stored in distilled water (N=12) or mineral oil (N=12) to evaluate the water diffusion over a 7-day period. Net water uptake (%) was also calculated as the sum of WS and SL. Data were submitted to 3-way ANOVA/Tukey's test (α=5%). The nanoleakage expression in three additional specimens per group was also evaluated after ammoniacal silver impregnation after 7 days of water storage under SEM. ResultsStatistical analysis revealed that only the factor "adhesive" was significant (p<0.05). Solvent evaporation had no influence in the WS and SL of the adhesives. CSE (control) presented significantly lower net uptake (5.4%). The nanoleakage was enhanced by the presence of solvent in the adhesives. ConclusionsAlthough the evaporation has no effect in the kinetics of water diffusion, the nanoleakage expression of the adhesives tested increases when the solvents are not evaporated.

Effects of pre- and post-simulated home bleaching with 10% carbamide peroxide on the shear bond strengths of different adhesives to enamel

Abstract Aim This in vitro study was undertaken to investigate the effects of pre- and post-simulated bleaching procedures with 10% carbamide peroxide on the shear bond strengths of different adhesives to enamel and to determine the failure modes of tested specimens. Materials and methods The specimens were randomly divided into three groups (n = 30) according to the sequence of bleaching and bonding procedures (control non-bleach, pre- and post-bleach groups). Each group was then subdivided into three subgroups (n = 10) according to the three types of adhesives: OptiBond Solo Plus (Kerr) and Single Bond Universal (3M-ESPE) used as etch-and-rinse and self-etch techniques. Resin composite cylinders were then placed with Filtek Z 250 (3M ESPE). The specimens were stored in distilled water at 37 °C for 24 hours prior to being thermocycled for 1000 cycles (at 5 and 55 °C). The samples in the pre- and post-bleach groups were also immersed daily in artificial saliva at 37 °C, and for two weeks after completion of the bleaching process. Shear bond strengths were measured with a cross-head speeds of 0.5 mm/min. Failure modes of debonded specimens were determined by stereomicroscopy (30×). The interface margins of resin composite to the different enamel conditions were observed by scanning electron microscopy (1000×) before shear bond strength testing. Results There were no significant effects of different enamel conditions (control non-bleach, pre-bleach and post-bleach) on the shear bond strengths of OptiBond Solo Plus Adhesive Agent or etch-and-rinse Single Bond Universal Adhesive Agent. Pre- and post-simulated home bleaching of enamel with 10% carbamide peroxide had an adverse effect on the shear bond strengths of self-etch Single Bond Universal Adhesive Agent. Conclusion In enamel, an etch-and-rinse approach with phosphoric acid remains the procedure of choice, since it guarantees the most durable bond to enamel. Therefore, selective phosphoric-acid-etching of enamel is highly recommended, followed by self-etching.

Effect of dentinal tubule orientation on the modulus of elasticity of resin-infiltrated demineralized dentin

The effect of tubule orientation of dentin on the elastic modulus of resin-infiltrated dentin was evaluated. Rectangular cylindricalshaped dentin specimens with their long axis parallel to and perpendicular to dentinal tubules were prepared from extracted premolars. Twenty-five mineralized specimens of each orientation were evaluated. The remaining specimens were then demineralized. The demineralized specimens and the demineralized following by infiltration with one of these adhesives; Optibond Solo Plus, Single Bond 2 or Prime & Bond NT, from each orientation were evaluated (25 specimens per group). The tubular orientation only affected the elastic modulus of mineralized dentin. The highest elastic modulus was observed for the mineralized dentin when the tensile force was applied parallel to the direction of tubules. The elastic modulus of demineralized dentin was the lowest. The adhesive resins increased the elastic modulus of demineralized dentin, but the differences among the three were insignificant.

Bond strength of dentin submitted to bleaching and restored with different materials

The use of adhesive composite resin with fluoride and with greater fluidity can be favorable to the restoration of the palatal/lingual face of teeth submitted to internal bleaching. Objective:This study evaluated the bond strength of adhesive systems and composite resins to bleached dentin. Material and methods: Forty maxillary canines were sectioned to obtain 40 blocks (5 x 5 mm) of intracoronary dentin. The fragments were included and bleached with 37% carbamide peroxide. After 7 days, the specimens were divided into two groups according to the adhesive system: with (Optibond Solo Plus) and without (Single Bond) fluoride and subdivided into 2 subgroups (n = 10) according to the composite resin: microhybrid (Z250) and flowable (Z350). The restoration was carried out through a bipartite matrix. After 24 hours, the specimens were subjected to shear bond strength test. The data (MPa) were analyzed by ANOVA and Tukey test (α = 0.05). Results: The best results (p &lt; 0.05) were obtained for fluoridated adhesive (7.44 ± 2.35) compared with that without fluoride (5.36 ± 2.01); flowable resin (7.76 ± 2.23) performed better than microhybrid resin (5.03 ± 1.72). When the two variables were associated, the highest results were obtained for the specimens restored with fluoridated adhesive and flowable resin(9.04 ± 1.92). Lower results were observed for non-fluoridated adhesive + microhybrid resin – control (4.24 ± 1.59), without statistically significant differences when compared with the fluoridated adhesive + microhybrid resin (5.83 ± 1.52). Conclusion: The combination with fluoridated adhesive and flowable resin increases the shear bond strength of bleached dentin.

Matrix metalloproteinase inhibitory properties of benzalkonium chloride stabilizes adhesive interfaces

This study evaluated the effects of different concentrations of benzalkonium chloride (BAC) on the preservation of adhesive interfaces created with two etch-and-rinse adhesives and its inhibitory properties on dentin matrix metalloproteinase (MMP) activity. The following groups were tested with the adhesive systems Optibond Solo Plus and All-Bond 3: Group 1, adhesive without inhibitor (control); Group 2, topical 2.0% chlorhexidine (2.0% CHX); Group 3, phosphoric acid with 1.0%wt BAC (BAC-PA); Group 4, 0.25% BAC-adhesive (0.25% BAC); Group 5, 0.5% BAC-adhesive (0.5% BAC); Group 6, 1.0% BAC-adhesive (1.0% BAC); and Group 7, 2.0% BAC-adhesive (2.0% BAC). Composite cylinders were fabricated, and shear bond strength (SBS) was evaluated after 24 h, 6 months, and 18 months of storage. Extracts from concentrated demineralized human dentin powder were subjected to SDS-PAGE and incubated in the presence of 0.25, 0.5, 1.0, and 2.0% BAC. Overall, stable bonds were maintained for 18 months. Improved bond strengths were seen for 0.5% BAC and 1.0% BAC when bonding with Optibond Solo Plus, and for 0.25% BAC and 0.5% BAC when bonding with All-Bond 3. Zymographic analysis revealed complete inhibition of gelatinolytic activity with BAC. Benzalkonium chloride, at all concentrations, inhibited dentin proteolytic activity, which seems to have contributed to the improved bond stability after 18 months for specific combinations of BAC concentration and adhesive.

Dentin and Enamel Bond Strengths of Dual-Cure Composite Luting Agents Used With Dual-Cure Dental Adhesives

Abstract Objective The purpose of this in vitro study was to evaluate and compare dentin and enamel bond strengths obtained with dual-cure composite luting agents when used with dual-cure dental adhesives. Methods Human molars were ground flat to expose enamel ( n = 80) or dentin ( n = 80). Specimens in each substrate group were randomly assigned to eight treatment sub-groups, according to four adhesive-luting agent combinations and two test conditions (with or without thermocycling). Pre-polymerized composite resin posts (TPH Spectrum) were luted to either the enamel or dentin surfaces with one of the following adhesive-luting agent combinations: (1) Xeno IV Dual Cure (dual-cure self-etch adhesive) and Calibra (dual-cure luting agent); (2) Prime & Bond NT Dual Cure (dual-cure total-etch adhesive) and Calibra; (3) OptiBond All-in-One Dual Cure (dual-cure self-etch adhesive) and Nexus 2 Dual Syringe (dual-cure luting agent); (4) OptiBond Solo Plus Dual Cure (dual-cure total-etch adhesive) and Nexus 2 Dual Syringe. For each treatment sub-group, half the specimens ( n = 10) were tested after 24 h storage in water at 37 °C, and the other half ( n = 10) were tested after thermocycling for 1800 cycles between water baths held at 5 and 55 °C, with a dwell time in each bath of 30 s, and a transfer time of 10 s. Bond strengths were measured in shear mode, and expressed in MPa. The fracture mode (adhesive, cohesive, mixed) was examined. Data were analyzed for statistical significance with a factorial ANOVA and post hoc tests. Results Mean enamel bond strengths ranged from 8.4 MPa for non-thermocycled OptiBond All-in-One|Nexus 2 to 35.5 MPa for non-thermocycled Prime & Bond NT|Calibra. Mean dentin bond strengths ranged from 14.5 MPa for non-thermocycled OptiBond Solo Plus|Nexus 2 to 30.9 MPa for thermocycled Xeno IV|Calibra. The fracture mode was predominantly adhesive for all groups. Conclusions On enamel, the total-etch adhesives performed better than their self-etch counterparts, while in dentin, the opposite was found, i.e., the self-etch adhesives performed better than their total-etch counterparts. Thermocycling for 1800 cycles did not affect the SBS of the materials tested to dentin and enamel.

Mechanical viscoelastic behavior of dental adhesives

ObjectivesThe purpose of the study was to evaluate the mechanical properties of dental adhesive materials at different testing temperatures after dry and wet storage. MethodsSpecimens (d=1mm, l=18mm) from six materials were tested: Silorane Adhesive System (SL), Heliobond (HE), One-Step Plus (OS), Optibond Solo Plus (OP), cmf Adhesive System (CF) and Protobond (PR). Static and creep testing was performed by applying a constant torque below the proportional limit of the materials, while dynamic testing consisted of dynamic torsional loading. Experiments were performed after 24h of dry and wet storage under temperatures from 21°C to 50°C and various viscoelastic parameters were calculated. ResultsShear modulus ranged from 0.19 to 1.99GPa, while flexural modulus from 0.67 to 5.69GPa. Most of the materials were affected by the presence of water and increase of temperature. OP showed the highest recovery after creep, while SL exhibited the highest permanent deformation. SignificanceContact with water after polymerization and increase of temperature resulted in a decline of the mechanical properties, especially for the HEMA-containing adhesives.

A comparative study of clinical effectiveness of fissure sealing with and without bonding systems: 3-year results

This prospective clinical study evaluated the sealant retention rate and caries-preventive efficacy of two fissure sealing techniques over a 3-year period. Subjects (87) aged between 6.5 and 11.5years were enrolled into two groups. In Group I (41 subjects), a resin-based fissure sealant (Fissurit FX, VOCO, Germany) was placed on all four sound permanent first molars (FPM-164 teeth) of each subject and in Group II (46 subjects) on 4 caries-free premolars (P1-2 182 teeth),using the following adhesives systems: Optibond FL (Kerr, USA), Optibond Solo plus (Kerr, USA), Prompt-L-Pop (3M ESPE, USA) or the conventional acid-etch technique. Sealed teeth were evaluated at baseline, 6, 12, 18, 24 and 36-month intervals with regard to retention and new caries development. Sealant retention was scored as: (1) complete retention; (2) partial loss; (3) complete loss of sealant. Wilcoxon-signed rank test was used to analyse the data. The complete retention rate was: Optibond FL/sealant 80.01-82.92%, Optibond Solo plus/sealant 73.78-74.27%, Prompt-L-Pop/sealant 42.84-53.65% versus acid-etch technique 62.86-71.44% on FPM and P1-2 (p<0.05). The fissure caries incidence rate was: Optibond FL/sealant 2.43-2.85%, Optibond Solo plus/sealant 2.85-4.76%, Prompt-L-Pop/sealant 24.40-34.28% versus acid-etch technique 16.66-17.14% (p<0.05) on FPM and P1-2. A statistically significant difference in sealant retention rate was observed between FPM and P1-2, using the self-etching adhesive system Prompt-L-Pop and acid-etch technique. It may be concluded that the use of adhesive systems Optibond FL and Optibond Solo plus yielded better fissure sealing performance.

Reconsidering the Double Etching of Enamel: Do Self-etching Primers Contaminate Phosphoric Acid-etched Enamel?

To evaluate the composite-to-enamel bond following double etching of the enamel using phosphoric acid and different self-etching (SE) bonding systems with and without the application of their respective acidic primers. The enamel surfaces of 90 human molars were ground (600 grit) flat and randomly divided into nine groups (n = 10). Three two-step SE systems (AdheSE, ASE; Clearfil SE Bond, CSE; OptiBond Solo Plus SE, OSE) were tested, both with and without primer application on enamel pre-etched with phosphoric acid under dry bonding conditions. As the controls, the SE systems were applied according to their original directions without pre-etching. All the specimens were built up with a microhybrid composite resin (Arabesk Top). After water storage for 24 h at 37°C, the bonded specimens were sheared to failure in the Zwicki 1120. Etching and failure patterns were evaluated using a scanning electron microscope (SEM). Shear bond strength was analyzed with two-way ANOVA and Tukey's test. Failure modes were analyzed with Fisher's exact test. Without pre-etching, CSE showed significantly higher bond strengths than ASE and OSE (p < 0.05). Enamel etching prior to the application of the SE systems tended to result in higher bond strengths, but significantly increased the values only for ASE (p < 0.05). Contamination of the pre-etched enamel with the SE primer decreased the bond strength by values of 19% for ASE (p > 0.05), 36% for CSE (p < 0.05), and 75% for OSE (p < 0.05). SEM analysis showed that omission of the priming step significantly increased the number of cohesive failures within the resin for OSE (p < 0.0001). Additional etching with phosphoric acid before the application of SE systems does not necessarily result in better enamel bonding, since unavoidable primer contamination of the pre-etched enamel was shown to significantly reduce the bond strength for two of the three systems tested.

Effect of dentin bonding agent diffusing through dentin slices on the reactive oxygen species production and apoptosis of pulpal cells.

Dentin bonding agents (DBAs) are cytotoxic to dental pulp cells. This study aimed to evaluate the effects of three DBAs (Optibond Solo Plus, Op; Clearfil SE Bond, SE; and Xeno III, Xe) after diffusion through 0.2-mm or 0.5-mm dentin slices on reactive oxygen species (ROS) production and apoptosis in dental pulp cells. The amounts of DBAs diffusing through 0.2-mm or 0.5-mm dentin slices were quantified using a UV-Vis spectrophotometer. The effects of diffused DBAs on ROS production and viability of dental pulp cells were investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay on Days 1 and 2. Flow cytometric analysis and double staining of treated dental pulp cells with Annexin V-fluorescein isothiocyanate (V-FITC) and propidium iodide (PI) were performed on Day 2. Xe showed greatest diffusion through dentin slices after 8-hour period, followed by SE and Op. Dental pulp cells produced a lesser amount of ROS, when treated with DBAs diffusing through a 0.5-mm dentin slice than through a 0.2-mm dentin slice for the same period of time. A small proportion of cells were TUNEL-positive after treatment with any of the three diffused DBAs. Annexin V-FITC/PI staining identified apoptotic cells; cell survival was higher in those cells treated with DBAs diffusing through a 0.5-mm dentin slice than through a 0.2-mm dentin slice. The three DBAs after diffusion through 0.2- or 0.5-mm dentin slice still exhibit cytotoxicity to dental pulp cells. However, the 0.5-mm dentin slice is found to be a better barrier than the 0.2-mm dentin slice to protect dental pulp cells from DBA-induced cytotoxicity.

Bond Strength of Self-etch Adhesives After Saliva Contamination at Different Application Steps

This study evaluated and compared the effect of saliva contamination and possible decontamination methods on bond strengths of two self-etching adhesive systems (Clearfil SE Bond [CSE], Optibond Solo Plus SE [OSE]). Flat occlusal dentin surfaces were created on 180 extracted human molar teeth. The two bonding systems and corresponding composite resins (Clearfil AP-X, Kerr Point 4) were bonded to the dentin under six surface conditions (n=15/group): group 1 (control): primer/bonding/composite; group 2: saliva/drying/primer/bonding/composite; group 3: primer/saliva/rinsing/drying/primer/bonding/composite; group 4: primer/saliva/rinsing/drying/bonding/composite; group 5: primer/bonding (cured)/saliva/rinsing/drying/primer/bonding/composite; group 6: primer/bonding (cured)/saliva/removing contaminated layer with a bur/rinsing/drying/primer/bonding/composite. Shear bond strength was tested after specimens were stored in distilled water at 37°C for 24 hours. One-way analysis of variance and Tukey post hoc tests were used for statistical analyses. For CSE, groups 2, 3, and 4 and for OSE, groups 6, 2, and 4 showed significantly lower bond strengths than the control group (p<0.05). CSE groups 5 and 6 and OSE groups 3 and 5 revealed bond strengths similar to the control. When saliva contamination occurred after light polymerization of the bonding agent, repeating the bonding procedure recovered the bonding capacity of both self-etch adhesives. However, saliva contamination before or after primer application negatively affected their bond strength.

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.

Surface preparation and isotropic shear bond strength properties of superficial bovine dentin

The effect of different types of surface preparation with SiC abrasive paper on the shear bond strength (SBS) of superficial bovine dentin obtained from the incisal, middle and cervical thirds were evaluated. Dentin substrates were obtained with twenty specimens for each locationgrit combination. Superficial dentin was exposed and prepared to 120-, 320-, or 600-grit SiC; the dentin surfaces were treated with Optibond Solo Plus (Kerr) and polymerized for 20 s. The specimens were placed in a jig, filled with resin composite Z100 (3M-ESPE), polymerized for 40 s according to manufacturer’s instructions, and stored for 24 h at 37℃ and 100% humidity. After 24 h, SBS was measured using a loading testing machine (Ul-tradent) and expressed in megapascals. A two-way ANOVA and Tukey test were used for data analysis. No statistically significant effect of the location (P = 0.254) or interaction grit-location (P = 0.629) were observed on SBS. Statistically significant effect of the grit on the SBS was detected (P

Isotropic shear bond strength behavior of superficial bovine dentin: A pilot study

The aim of this pilot study was to evaluate the shear bond strength of superficial bovine incisor dentin in different crown regions. Bonding was performed to the incisal, middle and cervical thirds of superficial bovine coronal dentin (n = 20) with a two-step etch-and-rinse adhesive (Optibond Solo Plus) and resin composite (Z100). Shear bond strength was evaluated at 24 h and failure modes of representative specimens wereobserved with FE-SEM. Non-parametric Kruskal-Wallis test with a significance level of 0.05 was used for data analysis. Mean shear bond strength values for the incisal, middle, and cervical thirds were 36.9 (3.1), 42.6 (2.6), and 37.1 (2.1) respectively with no significant differences evidenced between the crown thirds (p = 0.19). Observation of the failure mode of representative specimens demonstrated that specimens with high bond strength values exhibited predominantly mixed-type failures whereas low strength specimens exhibited adhesive failures between the dentin and adhesive. The absence of significant differences in shear bond strength between crown thirds indicate that, regardless of tubule orientation, any crown region can be used when superficial bovine incisor dentin is used for shear bond strength testing.

Postoperative sensitivity associated with low shrinkage versus conventional composites

Postoperative sensitivity in restorative dentistry can be related to preparation trauma, dentin adhesives' ability to seal open dentinal tubules, deformation of restorations under occlusal stresses and microleakage. The study assessed possible reduction in postoperative sensitivity with low shrinkage compared to conventional composites using different bonding agents and the influence of the operator skill on the incidence of postoperative sensitivity. Nine hundred and sixty permanent premolars and molars with primary carious lesions from patients 21 to 40 years old were used. Cavities 2 to 3 mm deep and with margins in enamel were prepared by four operators. Two operators had five years (A and B) and two had over 20 years (C and D) of clinical experience. Teeth were divided into eight groups each contained 120 restorations: (1) Els+James-2 (original formula), (2) Els+James-2 (new formula), (3) Els+Excite, (4) InTenSe+James-2 (original formula), (5) InTenSe+James-2 (new formula), (6) InTenSe+Excite, (7) Tetric Ceram+Excite, and (8) Point 4+OptiBond Solo Plus. At 14 days postoperatively, two independent operators, who did not take part in the clinical procedure, assessed postoperative teeth sensitivity using special questionnaires. Data were analyzed using non-parametric chi-square, Mann-Whitney and ANOVA tests. Group 8 showed significantly higher score than the other groups. Less postoperative sensitivity was reported with two low-shrinkage composites (groups 2, 3, and 5) but with no significant difference. There was no statistical difference between groups 1, 2, 3, 4, 5, 6 and 7. Operator A had the highest postoperative sensitivity score compared to the other three. Conventional composite material Point 4 with its bonding agent caused significantly more postoperative sensitivity than low shrinkage composites combined with different adhesives. Operator skill influenced the incidence of postoperative sensitivity.

Comparison of resin composite restorations microleakage: An &amp;lt;i&amp;gt;in-vitro&amp;lt;/i&amp;gt; study

The aim of this study was to compare the microleakage of total-etch and self-etch adhesives by three methods including dye extraction, dye penetration and fluid filtration with determining the correlation value among these techniques. Seventy-two premolar teeth were selected for this in vitro study and Class 5 cavities were prepared on the buccal surface of these at the cementoenamel junction area. It was applied for half of these cavities, Optibond Solo Plus (OSP) (two-step etch & rinse) and another half, Optibond All-in-One (OA) (one-step self-etch) and then all of them were restored with a light cure resin composite; Herculite XRV. Then samples were divided randomly into three subgroups based on the method of microleakage measurement (n = 12). In the first pair group, leakage was assessed by the dye extraction method. Dye penetration and fluid filtration methods were used in the second and third pair groups for the same purpose respectively. Data were analyzed by Paired t-test and Wilcoxon test and correlation coefficients (α = 0.05). There was no significant difference in the dye extraction (P = 0.657) and dye penetration (P = 0.732) methods between the microleakage of total-etch and self-etch adhesives. Microleakage of self-etch adhesive in fluid filtration technique was significantly more than total-etch adhesive (P = 0.012). No significant correlation was found among the results obtained with the three methods of microleakage evaluation. Adhesive systems showed variously behave in different methods of microleakage assessment.