Selim Erkut

Influence of previous provisional cementation on the bond strength between two definitive resin-based luting and dentin bonding agents and human dentin.

This study evaluated the effect of two different types of provisional luting agents (RelyX Temp E, eugenol-based; RelyX Temp NE, eugenol-free) on the shear bond strengths between human dentin and two different resin-based luting systems (RelyXARC-Single Bond and Duo Link-One Step) after cementation with two different techniques (dual bonding and conventional technique). One hundred human molars were trimmed parallel to the original long axis, to expose flat dentin surfaces, and were divided into three groups. After related surface treatments for each specimen, the resin-based luting agent was applied in a silicone cylindrical mold (3.5 x 4 mm), placed on the bonding-agent-treated dentin surfaces and polymerized. In the control group (n = 20), the specimens were further divided into two groups (n = 10), and two different resin-based luting systems were immediately applied following the manufacturers protocols: RelyX ARC-Single Bond (Group I C) and Duo Link-One Step (Group II C). In the provisionalization group (n = 40), the specimens were further divided into four subgroups of 10 specimens each (Group I N, I E and Group II N, II E). In Groups I N and II N, eugenol-free (RelyX NE), and in groups I E and II E, eugenol-based (RelyX E) provisional luting agents (PLA), were applied on the dentin surface. The dentin surfaces were cleaned with a flour-free pumice, and the resin-based luting systems RelyX ARC (Group I N and E) and Duo Link (Group II N and E) were applied. In the Dual bonding groups (n = 40), the specimens were divided into four subgroups of 10 specimens each (Group I ND, ED and Group II ND, ED). The specimens were treated with Single Bond (Groups I ND and ED) or One Step (Groups II ND and ED). After the dentin bonding agent treatment, RelyX Temp NE was applied to Groups I ND and II ND, and RelyX Temp E was applied to Groups I ED and II ED. The dentin surfaces were then cleaned as described in the provisionalization group, and the resin-based luting systems were applied: RelyX ARC-Single Bond (Group I ND and ED) and Duo Link-One Step (Group II ND and ED). After 1,000 thermal cycles between 5 degrees C and 55 degrees C, shear bond testing was conducted at a crosshead speed of 0.5 mm/minutes. One-way ANOVA, followed by a post hoc Tukey test (alpha = 0.05) was done. The dentin-resin-based luting system interfaces were evaluated under a scanning electron microscope. There was a significant reduction in the mean shear bond strength values of groups subjected to the provisionalization compared to the control and dual bonding technique groups (p < 0.05). The composition of provisional luting did not create a significant difference with regard to reducing shear bond strength values (p > 0.05). With regard to resin based luting systems, the shear bond strength values of the double-bond technique groups were not significantly different from the controls (p > 0.05).

Microleakage in Overflared Root Canals Restored with Different Fiber Reinforced Dowels

This study evaluated microleakage in overflared root canals restored with four different types of adhesively-luted fiber-reinforced dowels: DT Light Post (LP), Glassix (GL), Ribbond (RB) and StickTech Post (ST). Forty non-carious, single-rooted mandibular human premolars with straight root canals were prepared using a step-back technique and obturated with gutta-percha using lateral condensation. The restored roots were randomly divided into four groups (n=10). The root canals were overprepared, creating an overflared dowel space, and each dowel was adhesively luted using a total-etched adhesive (Single Bond) and dual-polymerizing luting agent (RelyX ARC). All specimens were thermal cycled 1000 times between 5 degrees C and 55 degrees C and stored in 2% methylene-blue solution for one week. The teeth were cut horizontally into three consecutive sections: apical (A), middle (M) and coronal (C). Each section was digitally photographed from the occlusal direction under a stereomicroscope. The images were transferred to a PC and stored in TIFF format. For each image, dye penetration was estimated as the ratio of methylene-blue-infiltrated surface divided by total dentin surfaces. The data were compared and statistically analyzed using the Kruskal-Wallis test (p<.05). The Mann-Whitney U test was used to compute multiple pairwise comparisons to determine differences between the experimental groups (p=.083). Dentin-luting agent fiber-reinforced dowel (FRD) interfaces were evaluated under a scanning electron microscope. Scanning electron microscopy (SEM) showed detachment of the luting resin from the dentin surface in varying degrees in all specimens evaluated. All groups showed considerable leakage at the sections evaluated. Significant differences were demonstrated between LP-RB for the apical and middle sections and between GL-RB, LP-RB and ST-RB for the coronal sections (p<.0083). Among the FRDs evaluated, the individually shaped polyethylene-reinforced dowel (Ribbond) showed the least overall leakage.

Effect of laser irradiation and cavity disinfectant application on the microtensile bond strength of different adhesive systems.

OBJECTIVE The aim of this study was to evaluate the effect of two different cavity disinfection procedures (chlorhexidine gluconate-based cavity disinfectant and Er,Cr:YSGG laser irradiation) on the bond strength of two different types of adhesive systems (Adper Single Bond 2 [SB] and Clearfil SE Bond [SE]). MATERIALS AND METHODS Thirty human third molars were ground flat to expose midcoronal dentin. After the dentin surfaces were polished with 600-grit silicon carbide paper, the teeth were randomly assigned to six groups (n = 5) according to the cavity disinfection procedure and the adhesive resin: Group I, etch and rinse adhesive (SB); Group II, self-etch adhesive (SE); Group III, cavity disinfectant application (cavity cleanser) + SB; Group IV, cavity disinfectant application + SE; Group V, laser irradiation (Er,Cr:YSGG laser, 20 Hz; 0.75 W; 15% water, 15% air) + SB; Group VI, laser irradiation + SE. For each group, the composite crown was incrementally fabricated with a composite resin. Following storage in distilled water at 37 degrees C for 24 h, the bonded specimens were serially sectioned into rectangular beams (n = 32). Bond strengths were determined using a microtensile tester at a crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA, and multiple comparisons were performed using post hoc Duncans test (p < 0.05). RESULTS Cavity disinfectant application and laser irradiation produced significantly higher bond strength values compared to the control group for SB. For SE, only laser irradiation improved the bond strength values compared to the control. There was a statistically significant decrease in the bond strength values of the specimens that were subjected to cavity disinfectant before SE application. The failure mode was mainly adhesive in all groups. CONCLUSION Cavity disinfectant application and laser irradiation may influence bond strength, depending on the adhesive system used. As a cavity-disinfecting procedure, laser irradiation might enhance the bond strength of etch and rinse and self-etch adhesive systems.

Effect of bleaching on staining susceptibility of resin composite restorative materials.

STATEMENT OF THE PROBLEM Effect of bleaching procedures on staining susceptibility of resin restorative materials is still questionable. PURPOSE The aim of this study was to evaluate the staining susceptibility of restorative materials bleached with 20% carbamide peroxide home bleaching agent and subsequently immersed in coffee and tea. MATERIALS AND METHODS Forty-two disk-shaped specimens were fabricated for each of the resin composites (Filtek Supreme XT [3M ESPE, St. Paul, MN, USA], Ceram-X Mono [Dentsply, Konstanz, Germany], and Aelite All Purpose Body [BISCO, Inc., Shaumburg, IL, USA]). The baseline color values were measured with a spectrophotometer. The specimens of each restorative material were randomly divided into two groups (N = 21). While the first group specimens were stored in distilled water (nonbleaching group-control), bleaching agent (Opalescence PF 20% [Ultradent Poducts, South Jordan, UT, USA]) was applied on the top surface of each specimen of the second group (bleaching group). After color change values were measured, the specimens were randomly divided into three subgroups (N = 7) according to the staining solutions. The color change values (DeltaE*ab) were calculated and the data were subjected to analysis of variance. Statistical significance was declared if the p value was 0.05 or less. RESULTS There was no statistically significant difference within each restorative materials DeltaE*ab values after bleaching (p = 0.714). Also, the staining solutions did not cause a statistically significant difference between DeltaE*ab values of bleaching compared with nonbleaching groups (p = 0.146). Significant interaction was found only between restorative materials and staining solutions (p = 0.000). CONCLUSION Bleaching of the tested resin composites did not increase their susceptibility to extrinsic staining in vitro. CLINICAL SIGNIFICANCE Bleaching did not affect staining susceptibility of the tested resin composite restorative materials. (J Esthet Restor Dent 21:407-415, 2009).

Repositioning a prosthetically unfavorable implant by vertical distraction osteogenesis.

Prosthetically unfavorable implant positions challenge patients and restorative dentists. Surgical correction of malpositioned implants may be an alternative technique for esthetically and biomechanically acceptable prosthetic restorations. This case report describes an alveolar distraction technique used to coronally reposition a dental implant and the 3-year results in the maintenance phase. To our knowledge, long-term follow-up of this method of correction is unprecedented. The present case report describes the repositioning of an apically positioned and fully osseointegrated implant at the right maxillary canine region using an alveolar distraction technique. Distraction was performed at 1 mm per day and ended when the implant moved 6 mm coronally. After a consolidation phase of 8 weeks, an implant-supported fixed prosthetic restoration was performed. Healing was uneventful after removal of the distractor. During the 3-year follow-up, the implant was fully functional with minimal probing depths, negligible signs of inflammation, and no further bone loss. This intervention illustrates the promise of an alveolar distraction osteogenesis procedure for vertical repositioning of apically positioned implants. This technique also provided soft and hard tissue remodeling to obtain an esthetic and stable restoration.

Effect of sodium ascorbate on bond strength of different adhesive systems to NaOCl-treated dentin

The aim of this study was to evaluate the effects of sodium ascorbate on bond strength of different adhesive systems to NaOCl-treated dentin. Eighty extracted molar teeth were used in the study. The buccal enamel surfaces were removed to obtain a flat dentin surface. The teeth were mounted in self-curing resin and dentin surfaces were irrigated with NaOCl for 10 min. Half of the specimens were treated with sodium ascorbate for 10 min. The teeth were randomly assigned to four subgroups according to the adhesive systems used (Clearfil SE Bond, Clearfil Tri-S Bond, Adper Prompt-L-Pop, Adper Single Bond 2). Bond strengths were determined with a Universal Testing Machine, at a crosshead speed of 0.5 mm/min. Data were statistically analysed using anova at a significance level of 0.05. Two-way ANOVA revealed that the effect of sodium ascorbate application on bond strength of adhesive systems to NaOCl-treated dentin was statistically significant (P < 0.05). The bond strength results were significantly influenced by the application of sodium ascorbate (P < 0.05) and there was a significant difference between the adhesive systems (P < 0.05). Although statistically significant differences were not demonstrated in all adhesive resin groups, sodium ascorbate application after NaOCl treatment improved the bond strength values.

Effect of different surface-cleaning techniques on the bond strength of composite resin restorations

STATEMENT OF PROBLEM Different techniques have been suggested for cleaning dentin surfaces after the removal of an interim prosthesis and before the application of a bonding agent. How different surface-cleaning techniques affect the bond strength of the composite resin restorations is not clear. PURPOSE The purpose of this study was to investigate the effects of different surface-cleaning techniques on the bond strength of composite resin restorations and the surface topography of the prepared tooth surfaces. MATERIAL AND METHODS The occlusal surfaces of 25 molars were ground until the dentin was exposed. A bonding agent and interim cement were applied on the teeth. The teeth were divided into 5 groups (n=5) according to the method used for surface-cleaning (microairborne-particle abrasion, alcohol, rubber-rotary instrument, desiccating agent, and control). Once the surfaces of the teeth had been cleaned, the same bonding material was applied to the teeth. A 5-mm-thick composite resin layer was built up. Each specimen was sectioned to microbars, and 6 centrally located beams were selected for microtensile testing (n=30) (1.10 ±0.10 mm). The data were statistically analyzed with 1-way ANOVA (1-sample Kolmogorov-Smirnov test). The Bonferroni test was used for significantly different groups (α=.05). One specimen from each group was observed under a scanning electron microscope and an atomic force microscope. Energy dispersive x-ray analysis also was performed. RESULTS Bond strength values were in the following descending order: microairborne-particle abrasion, desiccating agent, alcohol, rubber-rotary instrument, control. Differences between the microairborne-particle abrasion group and the remainder of the groups, desiccating agent--rubber-rotary instrument, desiccating agent-control, alcohol--rubber-rotary instrument, and alcohol-control groups, were statistically significant (P<.05). The microairborne-particle abrasion group displayed the roughest surface and a different surface topography from the remainder of the groups. Increased aluminum was observed in the microairborne-particle abrasion group. CONCLUSIONS Surface-cleaning techniques, except for the rubber-rotary instrument, increased the bond strength of composite resin. The roughest dentin surfaces and highest bond strength were achieved with the microairborne-particle abrasion technique.

The Effect of Different Polishing Sequences on the Adhesion of Streptococcus mutans to Feldspathic Porcelain

The aim of this research was to determine whether extra-oral surface treatments on feldspathic porcelain surfaces influence initial adhesion of Streptococcus mutans. Ninety-six porcelain specimen discs were fabricated and divided into six equal groups according to surface treatment: fine-grit diamond polishing (Group 1); self-glazing (Group 2); overglazing (Group 3); overglazing followed by a finishing procedure and then overglazing (Group 4); Pearl Surface polishing (Group 5); and Diamond Twist SCLTM polishing (Group 6). Surface roughness and hydrophobicity were assessed. An S. mutans suspension was incubated on each specimen group and evaluated. A one-way analysis of variance, post-hoc Tukey honestly significantly different test, Friedman test, and t-test were used for statistical analysis. Group 1 showed the highest surface roughness (p < 0.001) and bacterial adhesion (p < 0.05). Groups 5 and 6 specimen surfaces presented significantly higher contact angles (p < 0.05). Group 1 had the highest S. mutans adhesion, followed by Groups 3, 5, 6, 2, and 4 (p < 0.05). Reglazing after grinding may therefore decrease bacterial adhesion beneficially.

Management of interproximal soft tissue with a resin-bonded prosthesis after immediate implant placement: A clinical report

This report describes immediate implant placement after the extraction of a vertically fractured tooth. During the healing phase, a resin-bonded prosthesis was inserted as a provisional restoration. After the creation of the optimal emergence profile and papillae with the provisional restoration, the definitive metal ceramic crown was fabricated.

Influence of Dynamic Loading and Different Adhesive Systems on the Microleakage in Root Canals

Abstract The objective of this study was to evaluate the influence of dynamic loading and different adhesive systems on the microleakage in root canals. 80 human premolars were used in this study. The crowns of the teeth were sectioned at the cemento-enamel junction using a low speed diamond saw. After post space preparation, the roots were randomly assigned to 4 groups (n = 20) and restored with different adhesive systems. Group 1: Rely X ARC (RA) + Single Bond (SA), Group 2: Clearfil SA Cement (CL), Group 3: Panavia F 2.0 (PAN), Group 4: Rely X Unicem (RU). All the teeth were restored with the same type of glass fiber post and coronal cores built up with light-polymerizing hybrid composite resin. Half of the specimens of each group (n = 10) were subjected to additional dynamic loading in a universal testing machine. Apical parts of the roots were attached to computerized fluid filtration device for leakage measurement. The two-way ANOVA test was used first to detect overall significance, followed by two-sample t-test to identify which pairs of groups had significant differences. For each outcome statistical significance was set at p < 0.05. Dynamic loading significantly increased the microleakage values for Rely X ARC (p = 0.005), Clearfil SA Cement (p = 0.002) and Rely X Unicem groups (p = 0.001) but Panavia F 2.0 group was not affected by the dynamic loading (p = 0.111). One-way ANOVA test was applied to detect any significant differences in microleakage values for the adhesive systems. In the unloaded groups, there is no difference between the adhesive systems (p = 0.13). For the dynamically loaded groups, there is only significant difference between PAN and RA groups (p = 0.010). Post-hoc pairwise comparisons were done using Tukey’s multiple comparisons. Differences between Rely X ARC-Clearfil SA Cement and Rely X ARC-Panavia F 2.0 are statistically significant (p = 0.009, 0.013).