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Purpose: To investigate the effect of different chemical compositions of primers on the bond strength between nano-ceramic, polymer-infiltrated ceramic, and zirconia ceramic materials and dual-cure cement., Methods: Fifty 2 mm-thick specimens were prepared from Vita Enamic, Cerasmart, and Katana Zirconia UTML. The specimens were embedded in acrylic blocks. To standardize the surfaces, 600 grit silicon carbide abrasives were applied underwater for 60 seconds. Then, each section underwent grit-blasting using Al₂O₃ with a particle size of 50 µm at 10 mm and a pressure of 2 bar for 10 seconds. Each prepared sample from the experimental groups received the appropriate primer (Z-PRIME Plus, G-Multi Primer, Alloy Primer, Clearfil Primer Plus) according to the manufacturers' instructions. Subsequently, the prepared CAD-CAM specimens underwent cementation using Duo-Link Universal Adhesive Resin Cement with a cylinder mold of 2.6 mm diameter and 3 mm height. The cement was light-cured for 20 seconds from both sides. The specimens obtained were stored in distilled water at 37°C for 24 hours. The shear bond strength test of the specimens was performed using a Bisco Shear Bond Tester device. The data were statistically analyzed using ANOVA and the Kruskal-Wallis test (P< 0.05)., Results: The highest bond strength was observed in Z-Prime Plus applied specimens, regardless of material differences (Cerasmart 11.60±4.61; Vita Enamic 12.93±3.86; Katana Zirconia 13.85±4.00). The lowest bond strength, showing differences according to materials (P< 0.05), was found for Clearfil Ceramic Primer Plus-Cerasmart (7.88±3.90), Alloy Primer-Vita Enamic (7.90±2.14), and G Multi Primer-Katana Zirconia UTML (4.98±3.67)., Clinical Significance: Failure of the restoration usually occurs at the weakest point in this three-element structure, thus correct primer selection according to material type is important. Additionally, for all CAD-CAM materials used in the study, Z-Prime Plus showed significantly greater adhesion strength than other systems so it may be more appropriate for use in clinics., Competing Interests: The authors declared no competing conflict of interest., (Copyright©American Journal of Dentistry.)

PurposeTo determine the bond strength, nanoleakage and interfacial morphology of four self-etch adhesives bonded to superficial dentin.MethodsMicrotensile (MT) (n= 15) and single plane shear (SP) (n= 8) bond tests were performed using human dentin polished through 320-grit SiC paper. Clearfil Protect Bond (PB), Clearfil S3 Bond (S3), Prompt L-Pop (PLP) and G-Bond (GB) were used according to their manufacturers' instructions. Composite was applied as cylinders with a thickness of 4 mm with a 1 mm diameter and stored in water at 370C for 24 hours. Specimens were debonded with a testing machine at a cross-head speed of 1 mm/minute. Means and standard deviations of bond strength were calculated. Data were analyzed using ANOVA. Fisher's PLSD intervals were calculated at the 0.05 level of significance. Failure modes were determined at x100. The hybrid layer was revealed by treatment with 5N HC1/5% NaOCl or fractured perpendicular to the interface and sputter coated with gold. Specimens were viewed at x1,000, x2,500, and x5,000 in a field emission SEM at 15 kV. Teeth (n=2) sectioned into 0.9 mm-thick slabs were immersed in ammoniacal silver nitrate solution for 24 hours, rinsed and immersed in photo-developing solution for 8 hours. Specimens were sectioned (90 nm-thick) and observed under TEM.ResultsMeans ranged from 25.0 to 73.1 MPa for MT and from 15.5 to 56.4 MPa for SP. MT values were greater than SP, but were highly correlated (R2 = 0.99, P= 0.003) and provided the same order for the systems studied. Fisher's PLSD intervals (P< 0.05) for bond strength techniques and adhesives results were 1.7 and 2.3 MPa, respectively. Failures sites were mixed. TEM showed that hybrid layers were -0.5 pm for PB, GB and S3 and approximately 5 microm for PLP. SEM showed morphologic differences among adhesives. Silver nitrate deposits were observed within the interfaces for all adhesive systems.

Purpose: To investigate the effect of painless low-power Er:YAG laser irradiation of conventional and polymer-infiltrated ceramic network (PICN) type CAD-CAM resin-based composites (RBCs) on resin bonding., Methods: An Er:YAG laser system, phosphoric acid etchant, universal adhesive, RBC, and two types of CAD-CAM RBC block were used. Microtensile bond strength, fracture mode, scanning electron microscopy (SEM) observations of bonding interfaces and CAD-CAM surfaces, and surface roughness of ground and pretreated surfaces were investigated. As pretreatment methods, low-power Er:YAG laser irradiation and air-abrasion with alumina particles were used., Results: The effect of low-power Er:YAG laser irradiation of CAD-CAM RBCs on bonding to repair resin varied depending on the type of CAD-CAM RBCs., Clinical Significance: The low-power Er:YAG laser irradiation of the conventional CAD-CAM RBCs was shown to be effective as a surface pretreatment for resin bonding, while the laser irradiation of PICN-type CAD-CAM RBCs was not effective., Competing Interests: The authors declared no conflict of interest. This work was supported by JSPS KAKENHI [Grant-in-Aid for Scientific Research(C)] Grant Number 23K09190., (Copyright©American Journal of Dentistry.)

Purpose: This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS) in posterior restorations using a simplified etch-and-rinse adhesive, until 12 months of clinical service. Methods: 90 restorations were inserted in 45 patients to treat carious lesions or to replace existing posterior restorations with a depth > 3 mm. After cavity preparation, the simplified etch-and-rinse adhesive (Adper Single Bond 2) was applied on dry or wet dentin followed by a bulk-fill resin composite (Filtek Bulk Fill) under rubber dam isolation. The patient's spontaneous and stimulated POS was evaluated at baseline and after 7 days, 6 months, and 12 months of clinical evaluation. The secondary parameters (marginal discoloration, marginal adaptation, fracture and recurrence of caries) were evaluated by World Dental Federation (FD1) criteria after 7 days, 6 and 12 months of clinical evaluation. Results: No significant spontaneous and stimulated POS was observed when dry and wet dentin were compared (P> 0.05). A significant and higher risk of spontaneous POS (18.6%; 95% Cl 9.7 to 32.6) occurred up to 48 hours after restoration placement for both groups when compared to all evaluation times (P< 0.03). Flowever, the intensity of POS was mild at up to 48 hours with a difference between the dry and wet dentin groups (P> 0.79). When secondary parameters were evaluated, no significant difference between the groups were observed (P> 0.05). [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of silver diamine fluoride (SDF) application on the microshear bond strength (MBS) of glass-ionomer cements (G1C) to caries-affected dentin (Part 1) and dentin cleaning methods to reduce SDF's potential effect on MBS (Part 2). Methods: For Part 1, 56 extracted human teeth were randomly divided into eight groups with GIC, 38% SDF application and dentin substrate. Samples of artificial caries-affected human dentin were treated or not with 38% SDF and restored with conventional or resin-modified GIC. The same procedures were performed in sound dentin tested for MBS test after 24 hours. In Part 2, different dentin cleaning agents (water, aluminum oxide, and pumice slurry) were tested after SDF application. The procedure was performed on the group that presented the worst values for MBS in Part 1. Fracture mode was evaluated under scanning electron microscope. Data were statistically analyzed by ANOVA. Results: MBS was affected by the presence of caries and the type of material, with the conventional GIC the most affected (P< 0.05). Pumice slurry was superior in comparison to the other agents in cleaning SDF-treated dentin. Fracture evaluation showed more mixed failures in all the groups. [ABSTRACT FROM AUTHOR]

Purpose: To compare the in vitro effect of laser and bur preparation on marginal adaptation of Class V cavities restored with a 2-step self-etch and distinct universal one-component universal adhesives used in self-etching mode., Methods: 96 Class V cavities were prepared with conventional burs or with an Er:YAG laser. Four universal self-etch (Unibond Extra Low Shrinkage, All Bond Universal, SKB-100 and Prime&Bond active) and a 2-step self-etch adhesive (Clearfil SE Bond) that served as control were used to restore the cavities with direct composite. The percentages of continuous margins were evaluated by quantitative SEM analysis before and after a fatigue test consisting of 240,000 occlusal loads and 600 warm/cold thermal cycles., Results: The marginal adaptation of bur prepared restorations was statistically superior to laser-prepared ones. Class V cavities restored with Clearfil SE Bond and the one-component self-etching universal adhesives All Bond Universal and Prime&Bond active presented the highest and statistically similar percentages of continuous margins before and after loading under both bur and laser cavity preparation. The lowest percentages of continuous margins were observed in the groups restored with the low shrinking adhesive (Unibond ELS), with medians of 49 and 21 for bur and laser prepared cavities after loading., Clinical Significance: Class V cavities presented smoother and higher percentages of continuous margins when prepared by bur rather than by laser. The 2-step self-etch adhesive Clearfil SE Bond and 1-step self-etch universal adhesives All Bond Universal and Prime&Bond active showed a comparable marginal performance., Competing Interests: The authors declared no conflict of interest. The present manuscript is partly based on the doctoral thesis of Mrs. P. Noerpuspita, submitted to the University of Geneva to obtain the Dr.med.dent. degree. The Indonesia Endowment Fund for Education (LPDP) funded the scholarship of Dr. Noerpuspita., (Copyright©American Journal of Dentistry.)

Purpose: To assess the push out bond strength (POBS) of a syringe-mixed resin sealer and a premixed bioceramic sealer to root dentin exposed to different gutta-percha (GP) solvents and to determine the mode of failure., Methods: A total of 200 horizontal root slices (1 mm thickness) were prepared up to size 40, 0.04 taper and randomly divided into four main groups based on solvent (Endosolv, orange oil, chloroform) and control (saline), then subdivided into two subgroups based on sealer type (AH Plus Jet and iRoot SP). Samples were exposed to respective solvents for 5 minutes and after the final rinsing, canal spaces were filled with either AH Plus Jet or iRoot SP. POBS test was performed 2 weeks after incubation and mode of failure following POBS test was evaluated. Data were analyzed using two-way ANOVA and Dunnett post hoc analysis (P< 0.05). Failure mode patterns were categorized as adhesive, cohesive and mixed failures., Results: There was no significant difference (P> 0.05) in POBS between all solvent groups against the control in both AH Plus Jet and iRoot SP groups. Regardless of the use of solvents, AH Plus Jet group had significantly higher bond strength (P< 0.001) compared to iRoot SP group. The predominant mode of failure was mixed failure in all groups irrespective of type of sealer and exposure to solvents., Clinical Significance: This study showed that exposure to gutta-percha solvents (chloroform, orange oil and Endosolv) for 5 minutes did not affect the bond strengths of both iRoot SP (bioceramic sealer) and AH Plus (resin sealer) to root dentin., Competing Interests: The authors declared no conflict of interest. This study was funded through the Dental Research Postgraduate Grant, Faculty of Dentistry at the University of Malaya with reference number DRPG 22/21. The authors deny any conflicts of interest related to this study., (Copyright©American Journal of Dentistry.)

Purpose: To evaluate the shear bond strengths (SBS) of permanent 3D-printed resin (PR) to primary dentin using different luting agents., Methods: 90 primary teeth were prepared. 45 cylinders (3 x 3 mm) were printed using PR, and 45 cylinders were milled using a Z block (to control). The cylinders were bonded to primary dentin by using three types of luting agent [glass-ionomer cement (GIC), resin-modified glass-ionomer cement (RMGIC), and self-adhesive resin cement (SRC)]. The SBS values of the specimens were calculated, and the fracture modes were examined., Results: There was a statistically significant difference between the three different luting agents that were used to lute the PR to primary dentin (P< 0.001). Changing the material (PR or Z) did not affect the SBS values of the luting agents (P> 0.05). The adhesive failure between cement and dentin in the PR-SRC group was significantly higher than the other groups (P< 0.001). The SBS values of the newly developed PR to primary dentin with RMGIC and SRC were similar, but GIC showed lower values than the others., Clinical Significance: This laboratory study suggests that bond strength of the permanent 3D-printed resin can be like that of zirconia. As the resin-modified glass-ionomer cement and self-adhesive resin cement showed higher bond strength to primary teeth making the 3D-printed resin a treatment option., Competing Interests: The authors declared no conflict of interest., (Copyright©American Journal of Dentistry.)

Purpose: To evaluate the shear bond strength of two different resin cements to zirconia after treatment with cold atmospheric pressure plasma (CAPP) and other surface modification methods., Methods: 189 specimens fabricated from Vita YZ-HT zirconia discs were divided into nine surface treatment groups: (1) Untreated (U), (2) Sandblasting (S), (3) Laser (L), (4) Plasma (P), (5) Primer (PR), (6) Sandblasting + Primer (SPR), (7) Laser + Primer (LPR), (8) Plasma + Primer (PPR), (9) Laser + Plasma + Primer (LPPR). Surface roughness (Ra) and contact angles were measured (n= 10 each), and scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses were performed (n= 1 each). Specimens were cemented with RelyX Ultimate Clicker adhesive resin cement or Theracem self-adhesive resin cement. The specimens were subjected to shear bond strength (SBS) test. Modes of failure were examined under a stereomicroscope and visualized by SEM., Results: The S, PR, SPR, PPR and LPPR groups showed significantly greater Ra values than the U group. Significantly lower contact angles were observed in the S, P and L groups versus the U group. The SBS values of SPR, PPR and LPPR groups were significantly greater than those of the U group. CAPP can improve zirconia-resin cement bond strength by increasing the wettability of zirconia surfaces pretreated with the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) primer., Clinical Significance: The use of cold atmospheric pressure plasma in combination with a primer is a promising clinical procedure for improving resin cement bonding to zirconia surface., Competing Interests: The authors declared no conflict of interest. This study was funded by Firat University Center for Scientific Research Projects (Project ID. DHF.20.08)., (Copyright©American Journal of Dentistry.)

Purpose: To evaluate the effect of different surface treatments and primers with a CAD/-CAM resin composite block on its crown retention. Methods: 120 human molars were prepared with a 24° total convergence angle, 1.5 mm height, and axial walls in dentin. Surface area was measured by digital microscopy. Crowns were machined from CAD/CAM resin composite blocks. Teeth were randomly allocated to 12 groups (n= 10) based on possible combinations of three surface treatments: [Control, Alumina air abrasion (50-pm A12O3 at 0.28 MPa)]; 5% hydrofluoric acid etch (20-second scrub); silane application (with or without Kerr Silane primer); and adhesive application (with or without Optibond XTR Adhesive). Optibond XTR Adhesive was applied to the tooth preparations and crowns were bonded with MaxCem Elite cement. Crowns were fatigued for 100,000 cycles at 100 N in water and debonded in tension (1 mm/minute). Crown retention strength (maximum load/surface area) values were analyzed using a three-way ANOVA with Tukey's post-hoc tests (a= 0.05). Results: Surface treatment, silane and adhesive applications independently affect retention force (P< 0.05). All interactions were not significant (P> 0.05). Alumina airborne abrasion surface treatment, silane and adhesive applications all improve retention strength. Therefore, CAD/CAM resin composite crowns can withstand debonding while undergoing mechanical fatigue. Although all fonns of surface treatment and primer application improve bond strength, the highest mean retention strength values were recorded when the crowns were alumina particle abraded and coated with adhesive (with or without silane). [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of over-etching and subsequent use of different adhesive application approaches including active, double, preheated, and ultrasonic application on dentin bond strength., Methods: Dentin specimens from sound human third molars were prepared and allocated into six groups (n= 10 per group). In Group 1 (negative control), the dentin specimens were over-etched with phosphoric acid for 30 seconds, and a two-step etch-and-rinse adhesive (Prime & Bond XP; Dentsply Sirona) was applied for 20 seconds according to the manufacturer's instructions. In test Groups 2-5, the application of the adhesive varied: In Group 2, the adhesive was actively rubbed into the dentin surface, whereas in Group 3, a second adhesive layer was applied after light-curing of the first one. In Group 4, the adhesive was heated to 68°C prior to application, and in Group 5, the adhesive was ultrasonically activated. Acid-etching for 15 seconds and adhesive application for 20 seconds was performed in the positive control group (Group 6) according to the manufacturer's instructions. After light-curing and composite build-up [Ceram.x Spectra ST (HV); Dentsply Sirona], microtensile bond strength and fracture types were determined. Data were statistically analyzed by Kruskal-Wallis rank test, followed by post-hoc pairwise comparisons using Conover tests and P-value adjustment according to Holm (α= 0.05)., Results: Active, double, preheated, or ultrasonic adhesive application showed no significant effect on dentin bond strength when compared to the control groups. Predominantly adhesive failures were observed in all groups., Clinical Significance: A modification of adhesive application by using active, double, preheated, or ultrasonic application does not improve bonding to accidentally over-etched dentin., Competing Interests: The authors declared that they had no conflict of interest. The paper is partly based on the undergraduate theses of S. Simoni and P. Zwicky, University of Zurich, supervised by P. Burrer and T.T. Tauböck., (Copyright©American Journal of Dentistry.)

Purpose: To analyze the penetration depth and percentage perimeter with penetration of two fiber post cementing systems using confocal laser scanning microscopy (CLSM). Methods: 20 maxillary incisors were shaped with the Mtwo system and filled using lateral condensation and TopSeal mixed with fluorescein. Fiber posts were cemented. The samples were divided into two groups of 10 teeth each, according to the post cementing technique used: Prime&Bond NT combined with Rebilda DC using a total dentin etching technique (Group 1); or BisCem a self-adhesive cement (Group 2). Rhodamine B was incorporated in the adhesive systems. Cross-sections were prepared, with the selection of three sections (coronal, middle and apical thirds). CLSM was used to measure the percentage perimeter of the root canal showing penetration of the endodontic cement and of the adhesive system in the dentin tubules, together with the maximum penetration depth. The nonparametric Mann-Whitney U-test was used to compare the data referred to each of the three tooth sections between the two study groups. The Friedman test was used to compare the variables by coronal, middle and apical thirds within each group. Results: Greater penetration was recorded with the BisCem system in all thirds, with statistically significant differences in the case of the middle and apical thirds (P= 0.001). The percentage perimeter with penetration was also greater in all thirds with the BisCem system, though without significant differences between the two groups. Penetration depth and percentage were found to decrease in the coronal to apical direction in both groups. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the repair bond strength after storage in water, lactic and propionic acid after 7 days and 6 months and the sorption and solubility of resin composites used. Methods: Five cylinders of each resin composite (microhybrid, nanofilled and silorane-based composite) were prepared. Specimens were aged with thermocycling (5 and 55°C) 5,000 times. A repair procedure was performed using intraoral sandblasting with 50-μm aluminum oxide, application of an adhesive system and cylinder of composite was fabricated. Specimens were sectioned into beams and stored in three immersion media: water, propionic acid and lactic acid. The microtensile bond strength was measured after periods of 7 days and 6 months. Sorption and solubility were evaluated using 15 specimens (Ø= 6 mm; h= 1 mm) of each resin composite, which were prepared and assigned into three groups (n= 5) according to the immersion media (water, propionic acid and lactic acid). Data were analyzed using one-way/two-way/three-way ANOVA and Tukey's test (α= 0.05). Results: The resin composites, immersion media and time of immersion did not affect the repair bond strength (microhybrid 38.3 to 40.9 MPa; nanofilled 38.7 to 42.2 MPa; silorane 41.2 to 51.1 MPa). Additionally, the immersion media did not affect the sorption and solubility. The silorane-based composite presented the lowest sorption (10.5 to 12.1pg/mm3) and solubility (-2.4 to -2.7 μg/mm3), while the nanofilled methacrylate-based composite showed the highest sorption (32.1 to 33.6 pg/mm3). Regarding solubility, the nanofilled and microhybrid methacrylate-based composites did not present statistically significant differences. (Am J Dent 2015;28:367-372). [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of airborne-particle abrasion or diamond bur preparation as pretreatment steps of non-carious cervical root dentin regarding substance loss and bond strength. Methods: 45 dentin specimens produced from crowns of extracted human incisors by grinding the labial surfaces with silicon carbide papers (control) were treated with one of three adhesive systems (Group 1A-C; A: OptiBond FL, B: Clearfil SE Bond, or C: Scotchbond Universal; n= 15/adhesive system). Another 135 dentin specimens (n= 15/group) produced from the labial, non-carious cervical root part of extracted human incisors were treated with one of the adhesive systems after either no pre-treatment (Group 2A-C), pre-treatment with airborne-particle abrasion (CoJet Prep and 50 pm aluminum oxide powder; Group 3A-C), or pre-treatment with diamond bur preparation (40 pm grit size; Group 4A-C). Substance loss caused by the pre-treatment was measured in Groups 3 and 4. After treatment with the adhesive systems, resin composite was applied and all specimens were stored (37°C, 100% humidity, 24 hours) until measurement of microshear bond strength (pSBS). Data were analyzed with a nonparametric ANOVA followed by Kruskal-Wallis and Wilcoxon rank sum tests (level of significance: α= 0.05). Results: Overall substance loss was significantly lower in Group 3 (median: 19 pm) than in Group 4 (median: 113 pm; P< 0.0001). There were no significant differences in pSBS between the adhesive systems (A-C) in Group 1, Group 3, and Group 4 (P≥ 0.133). In Group 2, OptiBond FL (Group 2A) and Clearfil SE Bond (Group 2B) yielded significantly higher μSBS than Scotchbond Universal (Group 2C; P≤ 0.032). For OptiBond FL and Clearfil SE Bond, there were no significant differences in pSBS between the ground crown dentin and the non-carious cervical root dentin regardless of any pre-treatment of the latter (both P= 0.661). For Scotchbond Universal, the μSBS to non-carious cervical root dentin without pre-treatment was significantly lower than to ground crown dentin and to non-carious cervical root dentin pre-treated with airborne-particle abrasion or diamond bur preparation (P≤ 0.014). (Am J Dent 2015;28:362-366). [ABSTRACT FROM AUTHOR]

Purpose: This review describes the evolution of the use of dental adhesives to form a tight seal of freshly prepared dentin to protect the pulp from bacterial products, during the time between crown preparation and final cementation of full crowns. The evolution of these "immediate dentin sealants" follows the evolution of dental adhesives, in general. That is, they began with multiple-step, etch-and-rinse adhesives, and then switched to the use of simplified adhesives. Methods: Literature was reviewed for evidence that bacteria or bacterial products diffusing across dentin can irritate pulpal tissues before and after smear layer removal. Smear layers can be solubilized by plaque organisms within 7- 10 days if they are directly exposed to oral fluids. It is likely that smear layers covered by temporary restorations may last more than 1 month. As long as smear layers remain in place, they can partially seal dentin. Thus, many in vitro studies evaluating the sealing ability of adhesive resins use smear layer-covered dentin as a reference condition. Surprisingly, many adhesives do not seal dentin as well as do smear layers. Results: Both in vitro and in vivo studies show that resincovered dentin allows dentin fluid to cross polymerized resins. The use of simplified single bottle adhesives to seal dentin was a step backwards. Currently, most authorities use either 3-step adhesives such as Scotchbond Multi-Purpose or OptiBond FL or two-step self-etching primer adhesives, such as Clearfil SE, Unifil Bond or AdheSE. (Am J Dent 2015;28:321-332). [ABSTRACT FROM AUTHOR]

To evaluate changes in the physicochemical properties, water sorption (WS), solubility (SO), modulus of elasticity (E), ultimate tensile strength (UTS), and mierohardness (MH) tests were undertaken in zinc-doped dental adhesives. Methods: Two bonding resins, Adper Single Bond Plus (SB) and Clearfil SE Bond (SEB), were zincdoped by mixing them with 5, 10 or 20wt% of ZnO powder, or with 1 or 2wt% ZnCl2. Resin disks were made of each adhesive blend for the evaluation of WS, SO, and MH, and dumbbell-shaped specimens were prepared for E and UTS testing. Results: An increase in WS and SO was observed for adhesives doped with ZnCl2. A reduction in WS was observed for the adhesive blends containing 10% or 20wt% ZnO, while the SO was not altered in any of the ZnO-doped adhesives. An increase in E values was observed only for the SB adhesive doped with ZnCl2. For SEB-blends, the incorporation of zinc compounds did not alter the E values. UTS values decreased when SEB was doped with ZnO. SBblends doped with 20wt% ZnO significantly increased their MH, and the addition of zinc to the SEB-blends augmented the MH values in all cases. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the in vitro diffusion of 2-hydroxyethyl methacrylate (HEMA) from the resin cements through different thicknesses of dentin using high-performance liquid chromatography (HPLC) at two time intervals. Methods: 60 freshly extracted caries- and restoration-free human third molar teeth were used in this study. Standardized box-shaped Class I inlay cavities (6 mm long, 3 mm wide and 2 mm deep) were prepared in all teeth with a high-speed handpiece mounted on a standard cavity machine. The remaining dentin thickness (RDT) between the pulpal wall of the cavity and the roof of the pulp chamber was measured at multiple points for each tooth so that two main groups of 30 teeth each were prepared with an RDT range 0.5-1.9 and 2.0-3.5 mm, respectively. Each of these main groups was divided into three subgroups (n= 10), according to the resin cements tested (RelyX ARC, Panavia F 2.0, Multilink Automix). Lithium disilicate-based ceramic inlays (IPS Empress 2) were manufactured to restore the prepared cavities. A polypropylene chamber containing 1 ml distilled water was attached to the cemento-enamel junction of each tooth. Then, ceramic inlays were cemented with resin cements according to the manufacturers' instructions. Water elutes were analyzed by HPLC at 4.32 minutes and 24 hours. HEMA diffusion amounts were analyzed using three-way ANOVA and Tukey's HSD tests (P< 0.05). Results: HEMA was detected in the pulp chamber elutes of all the teeth. The amounts of released HEMA did not significantly differ between time periods. The diffused HEMA amounts were significantly different between the RDT of 0.5-1.9 and 2.0-3.5 mm (P< 0.05) and between resin cements tested (P< 0.05). Decreasing RDT substantially increased the amount of HEMA that diffused through the dentin to the pulp space. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of different repair procedures and storage time on microtensile bond strength (μTBS) of a resin composite to an older one from a simulated previous restoration. Methods: Composite disks were made by layering 2 mm-thick increments of a nanohybrid composite (Grandio) shade Al in a Teflon mold (4><8 mm). Afterwards, they were light-cured and stored (37°C/7 days) in a saline solution. Specimens were randomly divided into groups according to the surface treatment applied: (1) Composite surface was roughened with a bur (Cimara) and Solobond Plus adhesive was applied; (2) Sandblasting with 27 im aluminum oxide particles (KaVo Rondoflex), and adhesive application; (3) Air-abrasion with 30 |im alumina particles coated with silica (CoJet Sand), silane (Monobond- S) and adhesive application; (4) Negative control group with only adhesive application. Afterwards, Grandio composite (shade A3.5) was packed incrementally on the treated surface obtaining another disk (4x8 mm). Repaired blocks were stored (24 hours or 6 months) and afterwards (μTBS test was performed and failure mode was evaluated. Also, beams obtained from 8 mm-high composite blocks without any surface treatment were immediately submitted to μTBS test to determine Grandio composite cohesive bond strength (positive control group). Data were analyzed using ANOVA and Tukey's test (P< 0.05). Results: The repair procedure affected μTBS values (P< 0.001) while neither storage time nor interactions did (P> 0.05). All repair procedures achieved bond strength values higher than the negative control group but they did not reach the composite's cohesive bond strength. The overall conclusion was that an increased superficial roughness by means of a bur, silica coating or alumina sandblasting improved μTBS of the repaired composite and bond strength remained stable after 6 months. [ABSTRACT FROM AUTHOR]

To investigate the in vitro shear bond strength of two adhesives to bovine dentin contaminated with various astringents. Methods: 120 adult bovine incisors were collected and cut to obtain 240 specimens. The specimens were randomly divided into a self-etch adhesive group (N=120) and a total-etch adhesive group (N=120). Both of the groups were divided into the following six subgroups: the non-contamination group and the contamination groups 25% A12(S04)3 (Orbat sensitive), 25% A1C13 (Racestyptine), 10% A1C13 (Roeko Gingiva Liquid), 15.5% Fe2(S04)3 (Astringedent) and A1C13 Paste (Astringent Retraction Paste, N=20 in each subgroup). Each astringent was applied for 1 minute to the dentin surface before rinsing with water spray for 20 seconds. The respective adhesive was then applied according to the manufacturer's instructions. Two composite cylinders were shaped with a mold, cured on the dentin surface of each specimen and sheared off after 1 day and 1 week storage. The shear bond strengths (MPa) were recorded and analyzed with ANOVA. Results: In the self-etching adhesive group, all astringents showed negative effects on dentin bonding (P< 0.05). Astringent contamination did not have a negative effect on dentin bonding in the total-etch adhesive group (P> 0.05). [ABSTRACT FROM AUTHOR]

To evaluate the influence of the time elapsed between the application and photoactivation of Single Bond 2 (SB) on microtensile bond strength (|iTBS) and collagen exposure at the adhesive interface produced in the presence of intrapulp pressure. Methods: Dentin occlusal surfaces were prepared in 72 molars, and divided into eight groups (n= 9). After acid etching, SB was applied, with or without simulated intrapulp pressure, and remained undisturbed for 0, 20, 40 or 60 seconds, before photoactivation. Three teeth/group were processed for staining with Goldner trichrome and evaluation of the thickness of exposed collagen zone (CZ) at the base of the hybrid layer. Composite resin build-ups were placed on the remaining six prepared teeth prior to sectioning for microtensile testing. Data were submitted to ANOVA and Tukey tests (α= 0.05). Results: In the absence of pressure, immediate photoactivation resulted in the lowest μTBS, while the other groups did not differ among them. Under intrapulp pressure, the lowest values were observed after 60 seconds. There was no difference in the thickness of the exposed collagen zone among the groups without pressure. However, thicker layers were recorded in the presence of pressure after 40 and 60 seconds. Waiting 60 seconds between application and photoactivation of SB significantly reduced resindentin bond strength when pulpal pressure was simulated. [ABSTRACT FROM AUTHOR]

To compare the bond strength to human dentin for a variety of adhesive materials, including selfadhesive resin composites, self-etch and etch-and-rinse adhesive systems and glass-ionomer cement by means of micro shear bond strength (|j.SBS) test and SEM observations. Methods: Seventy-two human molars were sectioned to obtain a 2 mm-thick slab of mid-coronal dentin and were subsequently randomly divided into nine groups (n= 8). Nine conical frustum-shaped build-ups were constructed on the occlusal surface of each dentin slab using bonding agents (Group 1 : OptiBond FL; Group 2: OptiBond XTR) combined with a resin composite (Premise Flow), self-adhesive resin composites (Group 3: RelyX Unicem; Group 4: RelyX Unicem 2; Group 5: SmartCem2; Group 6: SpeedCEM; Group 7: Maxcem Elite; Group 8: Vertise Flow) and a glass-ionomer cement (Group 9: Ketac-Fil). Specimens were subjected to |iSBS test and observed with SEM. Data were analyzed by a mixed model and chi-square test. Results: The bond strengths measured in Groups 3-9 were significantly lower than those recorded in Groups 1 and 2. There were no significant differences in bond strengths between Groups 1 and 2 or between Groups 4 through 8. The bond strength measured in Group 9 was significantly lower than those recorded in Groups 4, 5, and 6 but was not significantly different than those recorded in Groups 3, 7, and 8. Failures were mainly adhesive in all groups. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate and compare the bonding of flowable resin composites and light-cured resin cements to dental ceramics., Methods: Grit-blasted zirconia plates were primed with MDP-containing adhesive. Lithium disilicate glasses plates were etched with HF and primed with silane. Two flowable resin composites with high (CM: 75 wt%/62 vol%) and low (BF: 67.3 wt%/47 vol%) filler contents, and two resin cements, again with high (C: 72 wt%/69 vol%) and low (R: 66 wt%/47 vol%) filler contents, were bonded to both types of pretreated ceramics. Shear bond strength (SBS) was measured after 24 hours water storage or 10,000 times thermocycling between 5 and 55°C. The viscosities and film thicknesses of the four resin-based luting agents (RBLAs) were also explored by rotational rheometer and metallurgical microscope severally., Results: Different RBLAs provided statistically different SBS values, with the high-filler specimens exhibiting higher SBS values than the low-filler specimens. The viscosities decreased in the order C > R > BF > CM. The film thicknesses for the BF and C groups were higher than those of the CM and R groups., Clinical Significance: This study provides evidence that flowable resin composites with high filler contents and low viscosities may serve as an alternative to light-cured resin cements for luting zirconia or lithium disilicate glass. This expands the range of light-cured luting agents available for bonding of veneers or other thin restorations, which is of great benefit to clinical practice., Competing Interests: The authors declared no conflict of interest. This study was supported by the Medical Research Projects of the Health Department of Jiangsu Province [M2020066] and the Priority Academic Program Development of Jiangsu Higher Education Institutions [2018-87]. S. Dai and Y. Chen contributed equally in this study., (Copyright©American Journal of Dentistry.)

Purpose: To evaluate the color parameters (CIELab*) after the cementation of ceramic disks of different thicknesses onto a resin substrate using four different shades of resin cements, and determine the color difference (AE) between the adhesively cemented disks and a 10 mm-thick A1 shade ceramic control (target color). Methods: Ceramic disks, simulating laminate veneers, with thicknesses of 0.5, 0.7 and 1.0 mm (shade Al, IPS Classic) were fabricated (n = 40) and cemented with a dual-cured resin cement (Variolink II, shades Al, bleach, opaque and transparent) onto 120 2 mm-thick resin composite substrates (shade A3.5, Adoro). Each ceramic disk was photocured for 80 seconds. The determination of the CIELab* parameters of each ceramic-cement-substrate set was performed with a spectrophotometer. A 10 mm-thick Al ceramic disk was used as a control. The results for the color difference (AE) obtained from L*, a* and b* parameters were analyzed using ANOVA and Tukey's test (a = 0.05). Results: The AE values ranged from 2.46 (1.0 mm, opaque cement) to 12.11 (0.5 mm, Al cement). The opaque cement showed the lower AE values, followed by the bleach, transparent and Al cements. With respect to the thickness of the ceramic, color differences between the target color and the group with 1.0 mm ceramic disks were smaller for all cement shades tested. Only the combination of 1.0 mm ceramic disks cemented with the opaque cement was able to mask the background color (AE < 3.7). The color differences between the control and the specimens cemented with opaque resin cement were smaller in comparison with the bleach, transparent and Al cements. [ABSTRACT FROM AUTHOR]

Purpose: This systematic review provides an overview of the different mechanisms proposed to regulate the degradation of dentin matrices by host-derived dentin proteases, particularly as it relates to their role in dental adhesion. Significant developments have taken place over the last few years that have contributed to a better understanding of all the factors affecting the durability of adhesive resin restorations. The complexity of dentin-resin interfaces mandates a thorough understanding of all the mechanical, physical and biochemical aspects that play a role in the formation of hybrid layers. The ionic and hydrophilic nature of current dental adhesives yields permeable, unstable hybrid layers susceptible to water sorption, hydrolytic degradation and resin leaching. The hydrolytic activity of hostderived proteases also contributes to the degradation of the resin-dentin bonds. Preservation of the collagen matrix is critical to the improvement of resin-dentin bond durability. Approaches to regulate collagenolytic activity of dentin proteases have been the subject of extensive research in the last few years. A shift has occurred from the use of proteases inhibitors to the use of collagen cross-linking agents. Data provided by 51 studies published in peer-reviewed journals between January 1999 and December 2013 were compiled in this systematic review. Results: Appraisal of the data provided by the studies included in the present review yielded a summary of the mechanisms which have already proven to be clinically successful and those which need further investigation before new clinical protocols can be adopted. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate two agents for bonding denture bases and teeth manufactured either by stereolithography (SLA) or by the subtractive mixed technique., Methods: Two types of cylinders [small for the tooth resin and large for the base resin) were designed using CAD software according to the ANSI/ADA 15-2008 (R2013)] specification. For SLA manufacturing, 30 small cylinders were shaped with Denture Teeth resin and 30 large cylinders with Denture Base resin. For the mixed technique, 30 large cylinders were manufactured by SLA with V-print dentbase resin, and 30 small cylinders were milled with a CediTEC DT disk. Half the specimens were bonded with liquid Denture Base resin and half with CediTEC Primer and Adhesive, according to the manufacturers' protocols. Shear bond strength was measured using a universal testing machine. The failure mode was noted for all the specimens., Results: The shear bond strength values were not significantly different between the groups (P> 0.05). Specimens bonded with liquid Denture Base resin displayed cohesive failure (P> 0.05, ײ= 0). Of the specimens bonded with CediTEC Primer and Adhesive, cohesive failures were observed with five specimens manufactured with the SLA technique and one specimen manufactured with the mixed technique (P> 0.05, ײ= 3.33). The Chi-square test results were significant between groups with different bonding agents regardless of the technique used (P< 0.001). Within the limitations of the present study, even if the shear bond strength values were similar, the failure mode analysis suggests that the uncured liquid Denture Base resin may be more effective than the CediTEC Primer and Adhesive for bonding denture bases and teeth manufactured either by SLA or the mixed technique., Clinical Significance: The present study suggests that the uncured liquid resin (Denture Base) used as a bonding agent and the denture base and tooth materials (V-Print and CediTEC DT) manufactured by SLA and the subtractive technique are clinically compatible., Competing Interests: The authors declared no conflict of interest., (Copyright©American Journal of Dentistry.)

Purpose: To evaluate the shear bond strength of yttria-stabilized zirconia (YSZ) ceramics based on the type of surface treatment, repair kit, and aging method used., Methods: YSZ ceramic blocks (N = 120) measuring 6 mm x 8 mm x 8 mm were randomly and equally divided into three groups for different surface treatments: (a) surface treatments recommended by the manufacturer (control), (b) air abrasion, and (c) Er:YAG laser. After surface treatment, either the Cimara intraoral ceramic repair kit or the Bisco intraoral repair kit were used on the samples. A resin composite was incrementally applied to the treated surfaces and light cured. Repaired samples were aged using either thermocycling or pH cycling. A shear bond strength test was conducted on all samples, and failure patterns were examined under a stereomicroscope. Data were analyzed using three-way ANOVA, Kruskal-Wallis, Mann-Whitney U, and Bonferroni corrected paired comparison tests., Results: Interactions were found between aging methods, surface treatments, and repair kits, as well as between repair kits and surface treatments (P< 0.05). Although there was no statistically significant difference in bond strength values between the air abrasion and control groups in the thermal cycle (P= 0.053) and pH cycle (P= 0.104) for the Cimara repair kit, the bond strength values of the Er:YAG laser groups were statistically significant (P< 0.001). For the Bisco intraoral repair kit, there was a statistically significant difference in bond strength values between surface treatments in both aging methods (Plt; 0.001). All groups showed 100% adhesive failure., Clinical Significance: The results of this study indicate the recommended use of the pH cycle aging method and primers containing carboxylic acid monomer and MDP for the repair of YSZ ceramics., Competing Interests: The authors declared no conflict of interest., (Copyright©American Journal of Dentistry.)

Purpose: To evaluate the quality of marginal and internal adaptation of Filtek Silorane composite in standardized class 1 cavities before and after thermo-mechanical loading using different application protocols of the Silorane System Adhesive (SSA). Methods: Five groups (n=10) of class 1 cavities were restored with Filtek Silorane using different SSA applications. Total bonding (TB): Group A (SSA), Group B (SSA without primer polymerization), Group C (enamel etching + SSA), Group D (enamel etching + SSA without primer polymerization) and Selective bonding (SB): Group E. Marginal adaptation was assessed on replicas in the SEM at x200 magnification before and after thermo-mechanical loading (3,000 x 5-55°C, 1.2.106 x 49N; 1.7Hz) under simulated dentin fluid. After loading, the samples were sectioned and the internal adaptation was evaluated as well. Results: The lowest scores of %CM (Continuous Margin) before/after thermo-mechanical loading being 80.8 (±8.2) / 32.1 (±8.3) were observed in the control group A. Enamel phosphoric acid etching prior to the application of the SSA resulted in significantly higher %CM before and after loading in comparison with the "non-etched" groups (P> 0.05). When enamel etching was performed before the application of the adhesive system, no statistically significant differences (P> 0.05) were observed regardless of how the SSA was applied (total vs. selective bonding). Internal adaptation was negatively influenced by omitting the SSA-primer polymerization (P> 0.05). [ABSTRACT FROM AUTHOR]

Purpose: To assess the influence of preliminary phosphoric acid-etching on shear bond strength (SBS) to enamel and dentin of a self-adhering restorative composite and of a new self-etch adhesive used in combination with the proprietary flowable composite. Methods: 100 human molars were selected. SBS was assessed on flat buccal enamel surfaces and mid-coronal dentin. Teeth from each group were divided into five subgroups (n=10): (1) FL: etch-and-rinse adhesive OptiBond FL/Premise flowable; (2) XTR: 2-step self-etch adhesive OptiBond XTR/Premise flowable; (3) eXTR: OptiBond XTR on etched substrates/Premise flowable; (4) VF: self-adhering flowable composite Vertise Flow; (5) eVF: Vertise Flow on etched substrates. Specimens were stressed in shear until failure. Failure modes were evaluated under a stereomicroscope. Data were analyzed by two-way ANOVA and Fisher's exact test (P< 0.05). Results: Dental substrate, material and between-factor interaction significantly influenced SBS (MPa). In FL group (16.83 ± 2.93) significantly higher SBS to enamel than in the other groups (XTR 8.59 ± 4.39; eXTR 7.04 ± 3.63; VF 6.61 ± 2,41; eVF 9.87 ± 4.24) was measured. On dentin FL (8.15 ± 3.88) performed similarly to XTR (10.60 ± 5.0), eXTR (9.60 ± 4.91) and eVF (5.48 ± 4.94); VF recorded significantly lower SBS (2.94 ± 2.79 MPa). Failure modes differed significantly among groups. [ABSTRACT FROM AUTHOR]

Purpose: To identify the remaining demineralized dentin (the permeable layer that allows leakage) when using primer-less wet bonding with a total etching period of 10 to 60 seconds compared with contemporary resin adhesives. Methods: Extracted human molars were selected and Class V cavities were prepared on the axial surfaces at the CEJ, providing margins in enamel and dentin for leakage testing using a basic dye (n= 10). Seven groups of conditioned teeth [1-1 etched for 10, 30, and 60 seconds (primer-less wet), All-Bond 2 and Single-Bond 2 (wet), AQ- Bond (self-etched), Super-Bond C&B (dry)J were used as bonding systems for resin composite restoration. All specimens were stored in water at 37°C for 24 hours before soaking in a 0.5% basic fuchsin solution for 24 hours. The distance of dye penetration was measured using stereomicroscopy. Results: No leakage at the enamel- and dentin-resin interfaces was found for all etching periods of 1-1 primer-less, Super-Bond C&B, and AQ-Bond specimens. However, leakage was observed at dentin margins in two wet with primer systems, All-Bond 2 (1.31 ± 1.39 mm) and Single-Bond 2 (0.37 ± 0.28 mm), which required phosphoric etching to remove a weak smear layer on prepared dentin. [ABSTRACT FROM AUTHOR]

Purpose: To compare a two-step etch-and-rinse adhesive system and a one-step self-etch adhesive system in order to evaluate the influence of clinical experience on dentin bond strength. Methods: 24 human molars were sectioned to obtain two 1 mm-thick slabs of mid-coronal dentin. Both surfaces of one of the two slabs that were obtained from each tooth were treated with a two-step etch-and-rinse adhesive (OptiBond Solo Plus), while both surfaces of the other slab were treated with a one-step self-etch adhesive (OptiBond All-In-One). 24 undergraduate, second-year students applied the adhesive on one of the two surfaces of each slab (Student group), while 12 dentists with experience in adhesive restorative dentistry (Expert group) applied the same adhesive on the other surface of the slab. Nine conical frustum-shaped resin composite (Premise Flowable) build-ups, whose smaller base was bonded to the dentin surface, were constructed on both surfaces of each dentin slab using a custom-made device. After thermocycling, specimens were subjected to microshear bond strength test. Data were analyzed by a multilevel statistical model. Results: The interaction term Experience × Adhesive resulted statistically significant (P< 0.0001). The bond strength (MPa) resulting from the self-etch adhesive was similar in the Student (27.8 ± 9.0) and in the Expert group (26.5 ± 7.0). The etch-and-rinse adhesive bond strength within the Student group (23.6 ± 10.4) was lower than that within the Expert group (28.1 ± 8.9). [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the bond strength of resin dentin interfaces created with adhesives applied on root dentin using the water wet or ethanol wet bonding teclmique. The morphology of resin dentin interfaces was evaluated using confocal microscopy. Methods: Four experimental resin adhesives (R#A to R#D) and one commercial three- step/etch and rinse adhesive were applied to the root canal dentin of endodontically treated single canal incisors using the water (control) or ethanol wet bonding technique. The ethanol wet bonding substrate was achieved by keeping the root canal immersed in absolute ethanol (100%) for 3 minutes. The root dentin bonded specimens were sectioned into beams, stored in distilled water (24 hours) and fmally tested for microtensile bond strengths (μTBS). Additional dentin surfaces were conditioned and bonded as previously described. They were prepared for the microscopy study and finally observed using confocal microscopy. Results: The ethanol wet bonding technique gave higher bond strength values for all the adhesives tested: in Group 1 (water wet bonding technique) no significant difference was found between the resins tested; the only exception being the most hydrophilic Resin #4 showing the highest bond strength values (P< 0.05). In Group 2 (ethanol wet bonding technique) no statistical differences were present between Resin #A and Resin #D. Resin #C showed the highest bond strength values. Confocal microscopy showed better resin diffusion and hybrid layer formation when the ethanol wet bonding was used. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the stability of the interfacial layer and leakage patterns between enamel, DEJ, dentin and three adhesive systems as demonstrated by either a dye or a silver nitrate technique to understand the marginal integrity of restored tooth substrates. Methods: Extracted human molars were cross-sectioned to prepare enamel, DEJ and dentin surfaces. Areas with the DEJ aligned in the middle were restored with prefabricated flat composite blocks using either Superbond C&B (SB), Panavia Fluorocement (PN) or Variolink II (VL) cements. 7 restored specimens for each cement were prepared to investigate the interfacial layer after chemical challenge using SEM. Restored and control specimens for each cement were prepared for leakage tests by soaking either in 0.5% basic fuchsin or 50% silver nitrate solutions for 24 hours (n= 8). The penetration depth of tracer was measured using stereoscopy and a digital micrometer. SEM backscattered electron image and energy dispersive x-ray spectrometry were used to detect the location of the silver. Results: Prepared SB hybridized enamel, dentin and DEJ were stable against soaking in HC1 followed by NaOC1 solutions whereas prepared DEJ- and dentin-resin interfacial layers were degraded, detached and thiimer than that of enamel in VL and PN specimens. No leakage was found at the enamel-resin interface for all cements and at the DEJ- and dentin-resin interfaces for SB specimens. VL specimens showed significantly greater leakage at the interface of dentin and DEJ than did PN specimens. (Am JDent 2010;23:285-291). [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the nanoleakage of one- and two-step self-etch adhesives bonded to artificial carious dentin. Methods: Deep dentin of 24 human molars was exposed and divided into four groups. One group served as control while the others were demineralized in artificial demineralization solution for 10 minutes, 6 hours, and 24 hours. Roots were sectioned and the crowns were bonded with one- and two-step self-etch adhesives (Clearfil S3 and Clearfil SE Bond) then restored with flowable composite (Estelite Flow Quick). Specimens were exposed to intrapulpal pressure through a tube connected to a barrel filled with silver nitrate solution in total darkness for 24 hours and then sectioned into two mid-slabs that were photo-developed and prepared for nanoleakage evaluation using FE-SEM and EDX. Penetration of silver into the hybrid and adhesive layers was evaluated and compared between adhesives and dentin condition. Data were statistically analyzed by Kruskal-Wallis test (α= .05). Results: Increasing depths of demin- eralization were observed with increasing demineralization time. There were statistically significant differences for both adhesives (P< 0.05) and dentin demineralization (P< 0.05) in hybrid and adhesive layers. Normal dentin interfaces revealed no or slight nanoleakage regardless of adhesive. The bonded interface treated with one-step Clearfil S3 showed significant differences between normal and demineralized dentin. Also a trend towards increases in nanoleakage with the increasing of the demineralization time was demonstrated. Different patterns of nanoleakage were observed within adhesives. (Am JDent 2010;23:279-285). [ABSTRACT FROM AUTHOR]

Purpose: This 24-month randomized paired tooth clinical study evaluated the performance of A11 Bond 3 used in the simplified (2-step) and full (3-step) versions. Methods: 33 patients, with at least two similar sized non-carious cervical lesions participated m this study. A total of 66 restorations were placed, half using the 2-step A11 Bond 3 (AB3-2) and the other half using 3-step A11 Bond 3 (AB3-3). The restorations were placed incrementally using the composite resin Aelite. The restorations were evaluated at baseline and after 6, 12 and 24 months following the modified USPHS criteria. Statistical differences between the adhesive were tested using with McNemar's test and clinical performance over time for each material with the Fisher's exact test (a 0.05). Results: After 24 months, six AB3-2 and four AB3-3 were rated as bravo for marginal discoloration but did not differ from each other significantly (P> 0.05). The retention rates at 24 months of AB3-2 and AB3-3 were 90.9% and 97.0%, respectively (P> 0.05). [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of different chlorhexidine concentrations on bond strength of resin composite to normal and caries-affected dentin using a self-etch primer adhesive. Methods: Thirty carious human molars were ground to expose flat dentin surfaces containing caries-affected surrounded by normal dentin. The teeth were divided into three groups. One group received no chlorhexidine pretreatment (control). The second and third groups received 2% or 5% chlorhexidine pretreatments, respectively before applying the self-etch primer adhesive (Clearfil SE Bond). Resin composite was applied to caries-affected dentin and to normal dentin on the same tooth with the aid of polyethylene tubes (0.9 mm diameter and 0.7 mm height). For micro-shear bond strength testing, each tooth was secured in a specially designed attachment jig to hold the specimens to the universal testing machine. Load was applied by the testing machine through a wire loop adjusted to the bonded interface at a crosshead speed of 0.5 mm/minute. Micro-shear bond strength was calculated and mode of failure was examined with a x40 stereomicroscope. Results: Statistical analysis revealed insignificant differences between control, 2% and 5% chlorhexidine pretreatment for normal as well as for caries-affected dentin groups. Also, there were insignificant differences in bond strength values between normal and caries-affected dentin for each treatment modality. Adhesive failure was the most common mode of failure. [ABSTRACT FROM AUTHOR]