Comparison of fiber reinforcing methods of composite resin: A flexural strength and stereo microscopy study.

This study aimed to compare the effect of fiber reinforcing methods on the flexural strength and failure modes of indirect composite resins. Based on the reinforcement methods, the bar specimens (3 × 3 × 25 mm) were divided into five groups (n = 20). Glass or polyethylene fibers were used for reinforcement of indirect composite resins. Fibers were either light polymerized and mixed with indirect composite resin or mixed with indirect composite resin after resin application and polymerized together. Indirect composite resin without fiber reinforcement was used as control. All five types of specimens were stored in distilled water at 37°C for 24 h. Half of the specimens were additionally thermocycled. Then the specimens were tested in a three-point bending test. Failure types were examined and categorized by using stereo microscope. The data were analyzed using two-way ANOVA and Tukey HSD test. Flexural strength was found to be significantly higher for fiber-reinforced indirect resin composites than control. However, the fiber-reinforced groups did not present any significant difference. Analysis revealed aging does not affect the flexure strength of fiber reinforcement of indirect composite resin. The study concluded that the flexure strength of indirect composite resins was improved with fiber reinforcement. Different fiber reinforcement methods demonstrated similar effects on the flexure strength of indirect composite resin. Reinforcement with glass or polyethylene fibers presented the potential to improve the mechanical properties of indirect composite resins. RESEARCH HIGHLIGHTS: Flexural strength of indirect composite resins are affected by the reinforcement of composites with glass or polyethylene fibers. Aging with thermocycling has no effect on the flexural strength of the indirect composite resins, however can cause catastrophic failures in material.

Influence of different implant-abutment connections on stress distribution in single tilted implants and peripheral bone: A three-dimensional finite element analysis.

BACKGROUND: The load transfer between the implant-bone interface depends on various factors, including loading type; material properties of the implant and prosthesis; and implant geometry, length, diameter, and shape. OBJECTIVE: The purpose of this study was to evaluate stress distribution in single tilted bone-level implants with different connections and peripheral bone under vertical and oblique loads using three-dimensional (3D) finite element analysis (FEA).METHOS.3D models of four different implant systems and their abutments were created from the data (computer-aided design) of original implants and abutments scanned with an optical scanner. The implants were placed in the bone block at degrees of 0°, 15°, and 30°. Then, a 3D model of the metal-ceramic crown was created and a 100-N total load was applied vertically and obliquely. RESULTS: Stress analyses showed variable results depending on the connection design and tilting angle; however, the tube in tube (TIT) connection type exhibited lower stress values in most loading and tilting simulations. CONCLUSIONS: Increase in tilting angle showed variable results in each connection design. The TIT connection design was found to be more successful in terms of stress distributions in the implant components and the peripheral bone.

Effect of different restorative crown and customized abutment materials on stress distribution in single implants and peripheral bone: A three-dimensional finite element analysis study.

STATEMENT OF PROBLEM: In recent years, the use of resin-matrix ceramics and polyetheretherketone (PEEK) abutments has been suggested to absorb excessive stresses on dental implants. However, only a few studies have evaluated the effect of these materials on stress distribution in implants and peripheral bone structure. PURPOSE: The purpose of this finite element analysis was to evaluate the biomechanical behaviors of resin-matrix ceramics and PEEK customized abutments in terms of stress distribution in implants and peripheral bone. MATERIAL AND METHODS: Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created by using the standard tessellation language (STL) data of original implant components. An anatomic customized abutment and a maxillary right second premolar crown were then modeled over the titanium base abutment. A bone block representing the maxillary right premolar area was created, and the implant was placed in the bone block with 100% osseointegration. Six different models were created according to combinations of restoration materials (translucent zirconia [TZI], lithium disilicate glass ceramic [IPS], polymer-infiltrated hybrid ceramic [VTE]), and customized abutment materials (PEEK and zirconia). In each model, the implants were loaded vertically (200 N) and obliquely (100 N). The stress distribution in the crown, implant, and abutments was evaluated through the von Mises stress analysis, and the stress distribution in the peripheral bone was examined through the maximum and minimum principal stress analyses. RESULTS: The oblique load resulted in high stress values in the implant components, restorative crown, and cortical bone. Low stress values were observed in the VTE crowns. Zirconia customized abutments exhibited higher stress values than PEEK customized abutments. The stress distributions in the implant and peripheral bone were similar in all models. CONCLUSIONS: Changes in restoration and customized abutment material did not affect stress distribution in the implant and peripheral bone.

An Alternative Prosthetic Approach for Rehabilitation of Two Edentulous Maxillectomy Patients: Clinical Report.

Obturator prosthesis is a common treatment method for maxillectomy patients for maintaining their oronasal separation and resuming their social lives. After tumor resection, the remaining anatomical structures have a significant effect on prosthesis retention. The present study describes the rehabilitation of two maxillectomy patients after cancer surgery using a prosthesis consisting of a denture and a special retentive obturator that is positioned in the anatomical undercuts of the nasal cavity. These patients have undergone total and subtotal maxillectomy surgery after the diagnosis of squamous cell carcinoma. The systemic and local health status of the total maxillectomy patient was not suitable for zygomatic implant surgery. Only one osseointegrated dental implant was placed into the left maxillary tuberosity area in the subtotal maxillectomy patient. In addition, the quality, vertical height, and horizontal width of the remaining bone structures in the maxilla limited the use of osseointegrated dental implants. Mechanical prosthesis retention was provided using a multiunit retentive mechanism composed of an orthodontic forsus fatigue resistant device (OFFRD), two Herbst appliances, and an acrylic piece associated with healthy keratinized mucosa. The OFFRD could easily apply a consistent force and push the acrylic pieces toward the retentive undercut under the control of the two Herbst appliances. Two OFFRD units in different directions were designed for the total maxillectomy patient, while only one OFFRD unit was placed on the opposite side of the osseointegrated implant in the subtotal maxillectomy patient. A sufficient retention was obtained for both patients. The patients were satisfied, and no major complications were observed in periodic controls.

Evaluation of shear bond strength of repair acrylic resin to Co-Cr alloy.

PURPOSE: The purpose of this study was to investigate the impact of different surface treatment methods and thermal ageing on the bond strength of autopolymerizing acrylic resin to Co-Cr. MATERIALS AND METHODS: Co-Cr alloy specimens were divided into five groups according to the surface conditioning methods. C: No treatment; SP: flamed with the Silano-Pen device; K: airborne particle abrasion with Al2O3; Co: airborne particle abrasion with silica-coated Al2O3; KSP: flamed with the Silano-Pen device after the group K experimental protocol. Then, autopolymerized acrylic resin was applied to the treated specimen surfaces. All the groups were divided into two subgroups with the thermal cycle and water storage to determine the durability of the bond. The bond strength test was applied in an universal test machine and treated Co-Cr alloys were analyzed by scanning electron microscope (SEM). Two-way analysis of variance (ANOVA) was used to determine the significant differences among surface treatments and thermocycling. Their interactons were followed by a multiple comparison' test performed uing a post hoc Tukey HSD test (α=.05). RESULTS: Surface treatments significantly increased repair strengths of repair resin to Co-Cr alloy. The repair strengths of Group K, and Co significantly decreased after 6,000 cycles (P<.001). CONCLUSION: Thermocycling lead to a significant decrease in shear bond strength for air abrasion with silica-coated aluminum oxide particles. On the contrary, flaming with Silano-Pen did not cause a significant reduction in adhesion after thermocycling.

The effect of alumina and aluminium nitride coating by reactive magnetron sputtering on the resin bond strength to zirconia core.

PURPOSE: Although several surface treatments have been recently investigated both under in vitro and in vivo conditions, controversy still exists regarding the selection of the most appropriate zirconia surface pre-treatment. The purpose of this study was to evaluate the effect of alumina (Al) and aluminium nitride (AlN) coating on the shear bond strength of adhesive resin cement to zirconia core. MATERIALS AND METHODS: Fifty zirconia core discs were divided into 5 groups; air particle abrasion with 50 µm aluminum oxide particles (Al2O3), polishing + Al coating, polishing + AlN coating, air particle abrasion with 50 µm Al2O3 + Al coating and air particle abrasion with 50 µm Al2O3 + AlN coating. Composite resin discs were cemented to each of specimens. Shear bond strength (MPa) was measured using a universal testing machine. The effects of the surface preparations on each specimen were examined with scanning electron microscope (SEM). Data were statistically analyzed by one-way ANOVA (α=.05). RESULTS: The highest bond strengths were obtained by air abrasion with 50 µm Al2O3, the lowest bond strengths were obtained in polishing + Al coating group (P<.05). CONCLUSION: Al and AlN coatings using the reactive magnetron sputtering technique were found to be ineffective to increase the bond strength of adhesive resin cement to zirconia core.

Effect of various surface treatments on the bond strength of porcelain repair.

This study evaluated the effect of surface treatments on the repair strength of composite resin on a feldspathic ceramic. Ninety ceramic specimens were divided into six groups. In the experimental groups, 4% hydrofluoric acid etching, Er:YAG laser irradiation, CO2 laser irradiation, airborne-particle abrasion, and silica coating were used as surface treatments. After the application of a porcelain repair kit, composite resin was placed on the treated surfaces. After a shear bond strength test, data were statistically analyzed (α = .05). Surface treatments increased the repair bond strength values (P < .05). Airborne particle abrasion and silica coating were found to be the most effective. CO2 laser showed higher repair strength values than Er:YAG laser.

Graft necrosis occurred after iliac crest reconstruction after mandibular segmental resection of ameloblastoma.

Ameloblastoma is an uncommon benign odontogenic neoplasm of the maxillofacial region constituting less than 1% of tumors of the oral cavity. Ameloblastomas have been categorized broadly into 3 biologic variants: cystic (unicystic), solid, and peripheral. Unicystic ameloblastoma is a rare and less aggressive variant of ameloblastoma. The aim of this report is to describe a case of cystic ameloblastoma treated with segmental resection and iliac graft reconstruction. The possible reasons of graft failure seen in our patient at the early stage of the healing were also discussed.

Effects of refractive index solutions on the color of different luting cements.

PURPOSE: The purpose of this study is to determine the effects of refractive index solutions on the color of different luting cements at different periods. MATERIALS AND METHODS: Fourteen disc-shaped specimens were prepared for three different universal shade luting cements. All specimens were divided into two groups and a phthalate ester and glycerol refractive index solution was applied to the specimens at different periods. Color differences (ΔE*) were calculated for before and after 5, 15, 60 min and 24 h periods of applying refractive index solutions. Data were analyzed with multiple analysis of variance (ANOVA) and mean values were compared by the Tukey HSD test (α = 0.05). RESULTS: Periods and periods-cement interaction were statistically significant (p ≤ 0.05). There was no statistically significant difference between the mean ΔE values of refractive index solutions and cement groups (p > 0.05). CONCLUSION: Refractive index solutions affected the color of luting cements.

The effect of different surface treatments on cement-retained implant-supported restorations.

The purpose of this study was to evaluate the effects of the various surface treatment methods on the retention of single crowns on implant abutments. The study included 50 single crowns that were cemented with adhesive resin cement onto the ITI solid abutments. The specimens were randomly divided into 5 groups, each including 10 specimens according to the following surface treatments: group C, control, abutments remained unaltered as control; group L, etching with CO(2) laser; group SB, sandblasting with 50-µm Al(2)O(3); group MS: coating with titanium nitride (TiAlN) with a radiofrequency magnetron sputtering system; and group SP, silicoating by Silano-Pen. After the surface treatment procedures were finished, the casted crowns were cemented onto the abutments, and thermocycling was applied to simulate oral environment. The uniaxial tensile force was applied to all test crowns using a universal test machine (Instron) with a crosshead speed of 0.5 mm/min. The load required to dislodge each crown was recorded in Newton. The lowest tensile bond strength values were obtained with group MS (223.26 ± 14.30 N) and significantly differ from all other groups except group C. Group SB showed highest test results (506.02 ± 18.04 N) and differs from other groups (P < .05). The test values that were obtained in group MS-group C did not show significant differences (P > .05). Sandblasting is an effective method to increase bond strength. Also, Silano-Pen and laser application is advisable for increasing the crown retention to abutments. Titanium aluminum nitride coating with magnetron sputtering technique seems to be ineffective.

Effects of different surface pre-treatments on the bond strength of adhesive resin cement to quartz fiber post.

OBJECTIVE: The purpose of this study was to evaluate the effect of mechanical and chemical surface treatment methods on the bond strength of resin cement to fiber post. MATERIALS AND METHODS: The roots of 36 maxillary central incisor teeth were mounted in auto polymerized acrylic resin blocks (10 × 15 mm) and the root canals were enlarged with the drills of post system (2.1 mm width, 12 mm length). Thirty-six fiber posts were randomly assigned to one of the following surface conditioning methods: silane coupling agent, methylene chloride etching, 24% hydrogen peroxide etching, air abrasion with 50 µm Al(2)O(3), 1-3 µm synthetic diamond particles and silica coating with 30 µm SiO(x). Fiber posts were cemented to the root canals with adhesive resin cement (Panavia F 2.0). Three slices of 1.5 mm thick were obtained from each root. Push-out tests were performed with a universal testing machine. The data were analyzed with one-way analysis of variance (ANOVA) and Tukey HSD tests (α = 0.05). The effect of the surface treatments were examined under a scanning electron microscope (SEM) and surface roughness were evaluated with a profilometer. RESULTS: Surface pre-treatment methods affected the bond strength (p < 0.05). The highest bond strengths were obtained by air abrasion with synthetic diamond particles, the lowest bond strength were obtained by etching with methylene chloride (p < 0.05). CONCLUSION: Mechanical surface pre-treatment methods showed higher bond strength values than chemical methods. Synthetic diamond particles may be an alternative method to increase resin cement bonding on the quartz fiber post surfaces.

The effects of different desensitizing agents on the shear bond strength of adhesive resin cement to dentin.

STATEMENT OF THE PROBLEM: The choice of desensitizing agent can affect the bond strength of adhesive resin cement to dentin. PURPOSE: The purpose of this study was to evaluate the effects of different dentin desensitizing agents on the bond strength of adhesive resin cement to dentin. MATERIALS AND METHODS: Sixty specimen teeth were randomly divided into six groups (n=10). Five groups of teeth were treated with a desensitizing agent containing sodium and calcium fluoride in cellulose alone, hydroxyethyl methacrylate (HEMA), benzalkonium chloride and sodium fluoride, HEMA and glutaraldehyde, an ormocer-based or a resin-based dentin desensitizer. The remaining 10 specimens served as controls. Adhesive resin cement was applied to the dentin surface. The shear bond strength was measured using a universal testing machine at a 0.5 mm/minute crosshead speed. The data were analyzed statistically with one-way analysis of variance and a Tukey's Honestly Significant Difference (HSD) test (α=0.05). In addition, dentin surfaces were examined by a scanning electron microscope. RESULTS: THE lowest bond strength was in the group treated with desensitizing agent containing sodium and calcium fluoride and the highest bond strength was from the group treated with desensitizing agent containing HEMA and sodium fluoride. CONCLUSIONS: Desensitizing agents containing sodium and calcium fluoride reduced the bond strength of adhesive resin cement. CLINICAL SIGNIFICANCE: The type of desensitizer used is an important factor regarding the bond strength of adhesive resin cements to dentin.

Determination of resin bond strength to zirconia ceramic surface using different primers.

OBJECTIVE: To evaluate the effect of different primers on the bond strength of adhesive resin cement to zirconia ceramic surface in vitro. MATERIAL AND METHODS: Thirty zirconia disk-shaped ceramic specimens (10×2 mm²) were divided into three equal groups for the application of different primers: Monobond-S, Clearfil Ceramic Primer and Signum Zirconia Bond. A further 10 specimens served as a control group. Forty composite resin blocks (6×2 mm²) were cemented (Panavia F 2.0) to zirconia ceramic specimens. Shear bond strengths were measured. Treated zirconia ceramic surfaces were examined using scanning electron microscopy. RESULTS: One-way ANOVA showed that the application of different primers affected the shear bond strength of adhesive resin cement to zirconia ceramic. The highest test values were obtained with application of Signum Zirconia Bond, and the lowest values were obtained in the control group. CONCLUSION: Signum Zirconia Bond is effective for increasing the bond strength of adhesive resin cement to zirconia ceramic.

Effect of air abrasion particles on the bond strength of adhesive resin cement to zirconia core.

OBJECTIVE: To evaluate the effect of air abrasion with different particles of different sizes and forms on the shear bond strength of adhesive resin cement to zirconia core. MATERIAL AND METHODS: Sixty zirconia core disks were produced and sintered. The specimens were divided into six equal groups for application of air abrasion procedures. The surfaces of the specimens were treated with one of five air abrasion particles: 30 µm silica-coated aluminum oxide particles; 1-3 µm synthetic diamond particles; 110 µm aluminum oxide particles; 30-50 µm synthetic diamond particles; and 60-80 µm cubic boron nitride particles. The remaining 10 specimens were untreated and served as controls. Composite resin disks were cemented to each of the zirconia core specimens. All specimens were stored in distilled water at 37°C for 24 h and thermocycled for 6000 cycles. The shear bond strength was measured using a universal testing machine at a crosshead speed of 1 mm/min. Data were statistically analyzed by one-way ANOVA with Tamhane tests (α = 0.05). The effect of the air abrasion procedures was examined using scanning electron microscopy. RESULTS: Air abrasion with different materials affected the bond strength (P < 0.001). The highest bond strengths were obtained by air abrasion with 30-50 µm synthetic diamond particles; the lowest bond strengths were obtained in the control group (P < 0.001). CONCLUSION: Air abrasion with 30-50 µm synthetic diamond particles, 60-80 µm cubic boron nitride particles and 110 µm aluminum oxide particles showed higher bond strength values than other methods.

The effect of laser treatment on bonding between zirconia ceramic surface and resin cement.

OBJECTIVE: The purpose of this in-vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the shear bond strength of resin cement to zirconia-based ceramic. MATERIAL AND METHODS: Forty zirconia core specimens (10-mm diameter, 2-mm thickness) were produced and embedded in the centers of autopolymerizing acrylic resin blocks. Subsequently, specimens were randomly divided into four groups, each containing 10 specimens, for different surface treatment methods. The details of the groups are as follows: Group C, no treatment applied (control); Group SB, bonding surfaces of ceramic disks were airborne particle-abraded with 110-µm alumina oxide particles; Group HF, bonding surfaces of ceramic disks were etched with 9.6% hydrofluoric acid; and Group L, bonding surfaces of ceramic disks were irradiated by a CO2 laser. A total of 40 composite resin disks were fabricated and cemented with an adhesive resin cement to the specimen surfaces. A universal test machine was used for the shear bond strength test at a crosshead speed of 1 mm/min. RESULTS: The highest shear bond strength values were obtained with Group L (20.99 ± 3.77 MPa) and the lowest values with Group C (13.39 ± 3.10 MPa). Although there was no significant difference between Groups C, HF and SB (P > 0.05), Group L showed a significant difference from all other groups (p < 0.05). CONCLUSION: All surface treatment methods improved the bond strength between resin cement and the zirconium oxide ceramic surface. CO2 laser etching may represent an effective method for conditioning zirconia surfaces, enhancing micromechanical retention and improving the bond strength of resin cement on zirconia ceramic.

Effects of three canal sealers on bond strength of a fiber post.

INTRODUCTION: This study evaluated the effects of three different endodontic sealers on the bond strength of a fiber post cemented with adhesive resin cement. METHODS: Forty-eight extracted maxillary central incisors were prepared with the step-back technique and randomly divided into four groups (n=12 for each group): group 1, control group (gutta-percha points only, no sealer); group 2, resin-based sealer (AH plus; Dentsply De Trey GmbH, Konstanz, Germany); group 3, zinc oxide-eugenol-based sealer (Endofill; Produits Dentaires SA, Vevey, Switzerland); and group 4, calcium hydroxide-based sealer (Sealapex; Kerr, Romulus, MI). The roots were obturated with gutta-percha using the cold lateral compaction technique. Fiber posts were cemented into the prepared post spaces with the adhesive resin cement Panavia F 2.0 (Kuraray Medical, Okayama, Japan). A push-out test was performed in a universal machine, and failure modes were observed. Morphologic changes of the root canal dentin surfaces were examined with scanning electron microscopy (SEM). RESULTS: One-way analysis of variance revealed that sealers have significant effects on bond strength (p<0.05). The control group had the highest mean push-out bond strength. No statistical difference was detected between the eugenol-based sealer group and the resin-based sealer group (p>0.05). The root surfaces were covered with the smear layer and debris in all the groups after post space preparation in SEM analysis. However, some of the dentin tubules were partially open in the control and calcium hydroxide-based sealer groups after the application of the resin monomer. CONCLUSION: The results of this study showed that the type of canal sealer and chemomechanical preparation of the root canals affect the bond strength of a fiber post cemented with resin cement.

Effect of fluoride-containing desensitizing agents on the bond strength of resin-based cements to dentin.

OBJECTIVE: The objective of this study was to evaluate the effect of desensitizing agents containing different amounts of fluoride on the shear bond strength of a dual polymerized resin cement and a resin-modified glass ionomer cement (RMGIC) to dentin. MATERIAL AND METHODS: One hundred human molars were mounted in acrylic resin blocks and prepared until the dentin surface was exposed. The specimens were treated with one of four desensitizing agents: Bifluorid 12, Fluoridin, Thermoline and PrepEze. The remaining 20 specimens served as untreated controls. All groups were further divided into 2 subgroups in which a dual polymerized resin cement (Bifix QM) or a resin-modified glass ionomer cement (AVANTO) was used. The shear bond strength (MPa) was measured using a universal testing machine at a 0.5 mm/min crosshead speed. The data were analyzed statistically with a 2-way ANOVA, Tukey HSD test and regression analysis (alpha=0.05). The effect of the desensitizing agents on the dentin surface was examined by scanning electron microscopy. RESULTS: The fluoride-containing desensitizing agents affected the bond strength of the resin-based cements to dentin (p<0.001). PrepEze showed the highest bond strength values in all groups (p<0.001). CONCLUSION: Regression analysis showed a reverse relation between bond strength values of resin cements to dentin and the amount of fluoride in the desensitizing agent (p<0.05).

Effect of fluoride-containing desensitizing agents on the bond strength of resin-based cements to dentin

OBJECTIVE: The objective of this study was to evaluate the effect of desensitizing agents containing different amounts of fluoride on the shear bond strength of a dual polymerized resin cement and a resin-modified glass ionomer cement (RMGIC) to dentin. MATERIAL AND METHODS: One hundred human molars were mounted in acrylic resin blocks and prepared until the dentin surface was exposed. The specimens were treated with one of four desensitizing agents: Bifluorid 12, Fluoridin, Thermoline and PrepEze. The remaining 20 specimens served as untreated controls. All groups were further divided into 2 subgroups in which a dual polymerized resin cement (Bifix QM) or a resin-modified glass ionomer cement (AVANTO) was used. The shear bond strength (MPa) was measured using a universal testing machine at a 0.5 mm/min crosshead speed. The data were analyzed statistically with a 2-way ANOVA, Tukey HSD test and regression analysis (α=0.05). The effect of the desensitizing agents on the dentin surface was examined by scanning electron microscopy. RESULTS: The fluoride-containing desensitizing agents affected the bond strength of the resin-based cements to dentin (p<0.001). PrepEze showed the highest bond strength values in all groups (p<0.001). CONCLUSION: Regression analysis showed a reverse relation between bond strength values of resin cements to dentin and the amount of fluoride in the desensitizing agent (p<0.05).

Effect of different surface treatments on the push-out bond strength of fiber post to root canal dentin.

OBJECTIVE: The purpose of this study was to evaluate the effects of different surface treatments on the bond strength of a fiber post to dentin. STUDY DESIGN: Sixty extracted human maxillary incisor teeth were manually shaped with K-files using the step-back technique. ISO size 45 files were used as master apical files. Post spaces were prepared and then the root canals were subjected to one of the following 5 surface treatments: irrigation with 5% sodium hypochlorite (NaOCl); treatment with ethanol, ethyl acetate, and acetone-based cleansing agent (Sikko Tim); irrigation with 17% EDTA; etching with 37% orthophosphoric acid for 15 seconds; and etching with 10% citric acid for 15 seconds. Fiber posts were luted using self-etching/self-priming dual polymerized resin cement. From the coronal part of each root, 3 slides of 0.6-mm thickness were obtained. A push-out bond strength test was performed by a universal testing machine at a crosshead speed of 0.5 mm/min. Dentin surfaces were examined under scanning electron microscopy (SEM) after different surface treatments. Data were analyzed with a one-way analysis of variance (ANOVA) and Tukey HSD test. RESULTS: ANOVA revealed that canal surface treatment affected the bond strength (P < .001). The highest bond strength was obtained in the Sikko Tim group. The results also showed that surface treatment methods increased the bond strength to dentin when compared with the control group. CONCLUSIONS: Sikko Tim group was the more effective surface treatment agent compared with EDTA, orthophosphoric acid, citric acid, and control groups; however, it could not remove the smear layer and sealer remnants effectively on radicular dentin surfaces. Removal of the smear layer and opening of dentinal tubules are not recommended when a self-etching/self-priming adhesive system is used.

The effect of dentin-cleaning agents on resin cement bond strength to dentin.

BACKGROUND: Provisional cement remnants on dentin affect the bond strength of resin cements to dentin. The authors investigated the effects of dentin-cleaning agents and etching systems on the bond strength of adhesive resin cement. METHODS: The authors removed the provisional cement from the dentin surfaces of the specimens and then cleaned the surfaces with the dentin-cleaning agents Sikko Tim (VOCO GmbH, Cuxhaven, Germany), Cavity Cleanser (Bisco, Schaumburg, Ill.) or Consepsis Scrub (Ultradent, South Jordan, Utah). They used adhesive resin cement after applying the different etching adhesive systems. Then they examined the dentin surfaces by using scanning electron microscopy. RESULTS: The authors analyzed data by means of a two-way analysis of variance with Tukey honestly significant difference tests (alpha= .05). They found that specimens cleaned with Sikko Tim and Consepsis Scrub had higher shear bond strength values than did those in the no-treatment control group or the group cleaned with Cavity Cleanser. The specimens treated with the total-etching adhesive system had higher shear bond strength than did those treated with the self-etching adhesive systems. CONCLUSIONS: Sikko Tim and Consepsis Scrub were effective in removing provisional cement. Adhesive resin cement showed higher bond strength when used in conjunction with the total-etching adhesive system. CLINICAL IMPLICATIONS: The use of an effective dentin cleaner before cementation with resin cement can increase bond strength.