Yonca Korkmaz

Effect of adhesive system type and root region on the push-out bond strength of glass–fibre posts to radicular dentine

AIM To compare interfacial strength in different thirds of the root canal amongst glass-fibre posts luted with four different adhesive luting agents. METHODOLOGY A total of 44 extracted human single-rooted teeth were randomly divided in four groups and restored using glass-fibre posts and the following luting agents: All Bond SE/Duo-Link (ABSE), All Bond 3/Duo-Link (AB3), BisCem (BC), Clearfil ED primer II/Clearfil Esthetic Cement (CLF). One week after luting, the samples were thermocycled in water, and then embedded in acrylic resin. Three sections (cervical, middle and apical) of 2 mm thickness were prepared from each specimen, and the post in each section was subjected to a push-out test. One additional specimen for each group was prepared for scanning electron microscopy analysis and the bonding effectiveness to dentine was assessed. The data were analysed using the Kolmogorov-Smirnov test, two-way anova, one-way anova, and the Scheffe test (P < 0.05). RESULTS The push-out bond strength values for BC and ABSE were not significantly different (P > 0.05), but both were significantly higher than the means for AB3 and CLF (P < 0.05) in the cervical and middle regions. The same trend was observed in the apical region, except for the AB3 and ABSE which were not significantly different (P > 0.05) from each other. There were significant differences in bond strength amongst root thirds, with a reduction in values from the cervical to apical third (P < 0.05). CONCLUSIONS The use of BisCem and All Bond SE/Duo-Link combination with their simplified application procedures may be considered an alternative to the currently used systems for luting glass-fibre posts in root canal.

Chemical Analysis of Enamel and Dentin Following the Application of Three Different At-home Bleaching Systems

PURPOSE To determine the change in the chemical composition of enamel and dentin as well as to evaluate the differences in surface texture of the same dental hard tissues following three at-home bleaching systems in vitro. METHODS Sixty extracted intact human anterior teeth were used in this study. Thirty teeth were used as samples for enamel, and the buccal surfaces of the remaining 30 teeth were abraded and used as dentin samples. Prior to bleaching treatments, calcium (Ca), phosphorus (P), potassium (K), sodium (Na), magnesium (Mg), fluoride (F), and oxygen (O) levels of each sample were measured using an energy dispersive spectrometer. The teeth were then randomly allocated into three groups according to the bleaching system used, as follows: GI, 10% carbamide peroxide (CP); GII, 20% CP; GIII, and 35% CP. Following the bleaching treatments, Ca, P, K, Na, Mg, F, and O measurements were repeated. The surface configurations were examined using scanning electron microscopy (SEM). The data were analyzed using Wilcoxon signed rank and Kruskal-Wallis tests followed by the Dunn test. RESULTS All three bleaching systems tested caused similar changes in the chemical composition of enamel and dentin. Bleaching systems decreased Ca and K, while F and O levels increased in enamel. In dentin, Ca, P, and K levels decreased; however, Na, F, and O levels increased. SEM observations revealed no deleterious effect on enamel and dentin. CONCLUSION The use of home bleaching agents could affect the chemical composition of dental hard tissues, whereas the change in the chemical composition of enamel and dentin was not affected by the CP concentration of the bleaching systems used.

Shear Bond Strength of Orthodontic Brackets Bonded using Conventional vs One and Two Step Self-etching/adhesive Systems

OBJECTIVE To assess and compare the effects of one- and two-step self-etching primer and adhesive with conventional acid-etching and bonding system on the shear bond strength of orthodontic brackets. MATERIALS AND METHODS The one-step self-etching primer and adhesive used was Clearfil tri-S bond, the two-step fluoride-releasing antibacterial self-etching primer and adhesive was Clearfil Protect Bond, and the fluoride-releasing conventional acid-etching and bonding system was Kurasper F Bond. Brackets were bonded to defect-free human premolars (n = 14 per group) according to each manufacturers recommendations by using light-cured bracket adhesive Kurasper F Paste with a light-emitting diode of a light-curing unit. The specimens were stored in deionized water at 37 degrees C for 48 hours and then tested in shear with a universal testing machine at a crosshead speed of 5 mm/min until the brackets debonded. The mode of failure of the brackets was determined by a modified adhesive remnant index. RESULTS Mean shear bond strength values were 9.00 MPa for Kurasper F Bond, 9.55 MPa for Clearfil Protect Bond, and 9.48 MPa for Clearfil tri-S Bond. One-way analysis of variance detected no statistically significant difference among groups (P = .98, P > .05). The predominant failure for the three groups was at the bracket-adhesive interface leaving less than 25% of the adhesive on the bracket base. CONCLUSIONS One-step self-etching adhesive and two-step fluoride-releasing antibacterial self-etching adhesive have sufficient mechanical properties for the bonding of orthodontic brackets.

Shear Bond Strength of Three Different Nano-Restorative Materials to Dentin

OBJECTIVES To evaluate the shear bond strength (SBS) of a nano-composite, a flowable nano-composite and a nano glass ionomer to dentin in vitro. MATERIALS AND METHODS Sixty human molars were ground flat, exposing the dentin surfaces, and they were randomly divided into five groups according to the restorative materials and adhesive systems used (n = 12/group). The restoratives were applied to all dentin surfaces according to the manufacturers instructions, using a special jig (Ultradent) in the following manner: Group 1: a nano-composite (NC) (Filtek Supreme XT-3M ESPE) was applied with a two-step self-etch adhesive (SE) (Adper SE Plus-3M ESPE); Group 2: NC was applied with an etch&rinse adhesive (SB) (Adper Single Bond 2-3M ESPE); Group 3: a flowable nano-composite (FNC, Filtek Supreme XT Flow-3M ESPE) was applied with SE; Group 4: FNC was applied with SB and Group 5: a nanofilled resin-modified glass ionomer (Ketac N100-3M ESPE) was applied with Ketac Nano Primer (3M ESPE). The bonded specimens were stored in distilled water (37 degrees C, 24 hours) and tested for SBS in a universal testing machine (1 mm/minute). Two specimens from each group were subjected to SEM evaluations of the adhesive interfaces. Failure modes were determined using a stereomicroscope. The mean SBS values were calculated and the data were analyzed with the Kruskal Wallis and Mann-Whitney-U tests (p < 0.05). RESULTS Mean SBS values (MPa) for the groups were 13.64; 7.83; 11.20; 4.12 and 0.64 for Groups 1, 2, 3, 4 and 5, respectively. Group 1 exhibited a significantly higher value than all the other groups; whereas, Group 5 had the lowest value (p < 0.05). The SE adhesive yielded higher bond values than the SB adhesive with NC and FNC restorative materials. Failure modes in all the groups were primarily adhesive. CONCLUSION The results demonstrate the capacity of the current two-step self-etch adhesive to outperform the etch&rinse adhesive in conjunction with the two nano-restoratives tested.

Microleakage of Class V Cavities with Different Adhesive Systems Prepared by a Diamond Instrument and Different Parameters of Er:YAG Laser Irradiation

OBJECTIVE The aim of this study was to evaluate the microleakage of composite resin restorations using two different dentine adhesive systems prepared with a diamond instrument and different parameters of Er:YAG laser irradiation. BACKGROUND DATA Information on this topic with regard to preparing class V cavities with different parameters of Er:YAG laser irradiation and adhesive systems is scarce. MATERIALS AND METHODS Two hundred class V cavities were assigned to ten groups (n = 20 each): group 1: Er:YAG laser (5 Hz, 600 mJ) + phosphoric acid (PA) + Adper Single Bond 2 (ASB2); group 2: Er:YAG laser (10 Hz, 300 mJ) + PA + ASB2; group 3: Er:YAG laser (15 Hz, 200 mJ) + PA + ASB2; group 4: Er:YAG laser (20 Hz, 150 mJ) + PA + ASB2; group 5: diamond instrument + PA + ASB2; group 6: Er:YAG laser (5 Hz, 600 mJ) + Adper Prompt L-Pop (APLP); group 7: Er:YAG laser (10 Hz, 300 mJ) + APLP; group 8: Er:YAG laser (15 Hz, 200 mJ) + APLP; group 9: Er:YAG laser (20 Hz, 150 mJ) + APLP; and group 10: diamond instrument + APLP. Cavities were restored with a nanofill composite (Filtek Supreme XT Body). After thermocycling, the specimens were stained with 0.5% aqueous basic fuchsin dye and sectioned bucco-lingually. Dye penetration was then scored. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction. The Wilcoxon signed ranks test was used to compare occlusal and gingival scores. RESULTS Leakage was seen in all groups at both the occlusal and gingival margins. The Kruskal-Wallis test showed statistically significant differences among the 10 groups (p < 0.001). The gingival margins had more microleakage than the occlusal margins (p < 0.001). Pairwise analysis by the Mann-Whitney U test showed that statistically significant differences (p < 0.05) in microleakage were found between groups 3 and 5 (3 > 5), 5 and 7 (7 > 5), and 7 and 8 (7 > 8) at the gingival margin, and between groups 3 and 6 (6 > 3), 3 and 7 (7 > 3), 4 and 6 (6 > 4), and 4 and 7 (7 > 4) at the occlusal margin. CONCLUSION We concluded that for all groups, microleakage values were higher at the gingival margins. The use of the Er:YAG laser for cavity preparation with different parameters and different dentine adhesive systems influenced the marginal sealing of composite resin restorations.

Leakage Pathway of Different Nano-Restorative Materials in Class V Cavities Prepared by Er:YAG Laser and Bur Preparation

OBJECTIVE The aim of this study was to evaluate the microleakage of different nano-restorative materials in Class V cavities prepared by Er:YAG laser and bur preparation. MATERIALS AND METHODS Class V cavities were prepared on the buccal and lingual surfaces of 72 premolars by Er:YAG laser or bur. The occlusal margins were in enamel and the cervical margins were in cementum. Teeth were randomly assigned to six groups of 12 teeth (n = 24 cavities) each as follows: Group 1, Er:YAG laser preparation (E)+Ketac N100 (K); Group 2, bur preparation (B)+K; Group 3, E+Adper Prompt L-Pop (A)+Filtek Supreme XT Flow (FSF); Group 4, B+A+FSF; Group 5, E+A+Filtek Supreme XT (FS); Group 6, B+A+FS. All teeth were thermocycled 500 times. Ten teeth from each group were chosen for the microleakage investigation and two teeth for the scanning electron microscope evaluation. Teeth prepared for the microleakage test were immersed in 0.5% basic fuchsin dye for 24 h. Afterwards, the teeth were sectioned and observed under a stereomicroscope for dye penetration. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests (p < 0.05). RESULTS There were significant differences between occlusal and cervical regions for all groups (p < 0.05) except for Group 1. Bur-prepared cavities showed less microleakage in all groups for enamel (p < 0.05); however, in cementum there were no significant differences between the bur- and laser-prepared cavities in nano-glass ionomer and flowable composite groups (p > 0.05). CONCLUSION It may be concluded that the cavities prepared by Er:YAG laser showed higher degree of microleakage than those conventionally prepared by bur, regardless of the restorative material at enamel margins.

Effect of Er,Cr:YSGG laser irradiation on the apical sealing ability of AH Plus/gutta-percha and Hybrid Root Seal/Resilon Combinations

OBJECTIVE The objective of this study was to evaluate the sealing ability of 2 different resin-based endodontic filling systems after smear layer removal with 2 different techniques. STUDY DESIGN Extracted human single-rooted teeth (n = 74) were instrumented using HERO Shaper rotary instruments and irrigated with 1 mL of 2.5% NaOCl between each instrument. Additionally, the canals received either an extra 3-minute rinse with 2 mL of 17% EDTA or a 40-second Er,Cr:YSGG laser treatment. The root canals were filled with either Hybrid Root Seal/Resilon combination or AH Plus/gutta-percha combination using lateral condensation technique (n = 11). Apical leakage quantity was measured with the computerized fluid filtration meter at 1 and 4 weeks. One root from each group, which was not submitted to the fluid filtration test, was selected for scanning electron microscopy (SEM) analysis. Statistical analysis was performed using 3-way ANOVA and the post hoc Tukey HSD test (α = 0.05). RESULTS A significant decrease was observed in the microleakage values of all the experimental groups tested with time (P < .0001). EDTA + AH Plus/gutta-percha combination exhibited the least microleakage, whereas laser irradiation + Hybrid Root Seal/Resilon combination showed the greatest microleakage at each of the 2 time periods. Each experimental combination exhibited architecture in SEM that seemed to correlate with its sealing performance. CONCLUSION Er,Cr:YSGG laser treatment does not enhance the sealing ability of the sealers compared with EDTA application. The root canal adaptation and sealing ability of the Hybrid Root Seal/Resilon combination is not superior to that of the AH Plus/gutta-percha combination.

Sealing capacity of a flowable composite, as a protective base, with different conditioning methods in nonvital bleaching.

OBJECTIVE The purpose of this in vitro study was to determine the microleakage of a nano-flowable composite used as a protective base, applied with different conditioning methods in nonvital bleaching. MATERIALS AND METHODS Forty root-filled teeth were divided into four treatment groups (n = 10 per group): group 1--Er:YAG laser etching + Adper Single Bond 2; group 2-37% phosphoric acid + Adper Single Bond 2; group 3--Adper Prompt L-Pop; and group 4--No treatment. A nano-flowable composite (Filtek Supreme Flow) base was used in each group. For a 24-h period, 40% hydrogen peroxide solution was applied to the pulp chambers, and they were subsequently subjected to a dye (silver nitrate) challenge for 4 h. After the dye was washed out with water, each tooth was cut in half and both halves were exposed to sunlight for 2 h to promote oxidation of the dye, turning it black. Finally the sections were examined under 4x magnification to determine the degree of leakage as assessed with a four-point scale. Statistical analysis was performed with the Mann-Whitney U test. RESULTS There were no significant differences between groups 1, 2, and 3 (p > 0.05), but the teeth in group 4 had significantly higher microleakage scores than the teeth in the other groups (p < 0.05). CONCLUSION Self-etching adhesive application, Er:YAG laser etching, and phosphoric acid etching combined with an adhesive system all showed similar microleakge scores when a nano-flowable composite was applied as a protective base in nonvital bleaching.

Effect of adhesive systems on microleakage in endodontically treated teeth restored with glass fiber posts

The effect of adhesive systems on microleakage in endodontically treated teeth restored with glass fiber posts was studied. Forty carious and crack-free premolars were prepared using a stepback technique and obturated with gutta-percha. The endodontically treated roots were randomly divided into four groups (n = 10). Glass fiber posts cemented following adhesive luting agents; group 1: All Bond 3/Duo Link (ALB/DL), group 2: One-Step Plus/Duo-Link (OSP/DL), group 3: Panavia F 2.0/Panavia ED Primer II (PAN/ED), and group 4: Rely X Unicem (RU). All specimens were thermal cycled and stored in basic fuchsin solution for one week. The roots were sectioned horizontally into three sections: apical, middle, and coronal. The occlusal direction of each section was digitally photographed under a stereomicroscope. Dye penetration area was calculated as the basic fuchsin infiltrated surface divided by total dentin. The data were statistically analyzed using the Mann–Whitney U and Wilcoxon Signed Ranks Tests (α = 0.05). The mean area measurements were ranged between 0 and 3.7357. According to the Mann–Whitney U test, there was no significant difference among the groups and sections (p > 0.05). Intragroup comparisons showed a significant difference between coronal-apical and middle-coronal sections in Panavia group (p = 0.043) by Wilcoxon Signed Test. It was found that there was no significant difference among four groups and the apical, coronal, and middle sections. The only difference was found for the group of PAN/ED between coronal-apical and coronal-middle sections.