Browsing by Author "Ozcan, M."

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Effect of Different Mechanical Cleansing Protocols of Dentin for Recementation Procedures on Micro-Shear Bond Strength of Conventional and Self-Adhesive Resin Cements
(Elsevier Sci Ltd, 2013) Bavbek, A. B.; Goktas, B.; Sahinbas, A.; Ozcopur, B.; Eskitascioglu, G.; Ozcan, M.
Service life of debonded indirect dental restorations could be prolonged by recementation. This process requires removal of cement remnants from dentin. This study evaluated the effect of different mechanical cleansing protocols of dentin for recementation procedures on micro-shear bond strength (mu SBS) of conventional and self-adhesive resin cements. The labial surfaces mandibular incisors (N=200) were ground with a low speed saw to expose the corona] dentin. The teeth were randomly divided into two subgroups (n: 100 per group) and received either (a) conventional (Panavia F 2.0, Kuraray, PAN) or (b) self-adhesive (Clearfil SA, Kuraray, CSA) resin cement. Resin cements were condensed into polyethylene molds incrementally and photo polymerized using an LED polymerization unit. Specimens were stored in distilled water at 37 degrees C for 24 h and subjected to mu SBS (0.5 mm/min). Resin cement remnants on bonded dentin surfaces were removed using by (a) composite finishing bur (cb), (b) tungsten carbide bur (ob), (c) ultrasonic scaler tip (sc) or (d) pumice-water slurry (pw). Non-cleaned teeth acted as the control group (cn) (n: 20 per subgroup). After cleaning, the same cement type was rebonded simulating clinical recementation. Failure types were analyzed using optical microscope and Scanning Electron Microscope (SEM). Data (MPa) were analyzed using Wilcoxon Signed Ranks, Mann-Whitney U and Bonferroni tests (alpha=0.05). Overall, CSA (6.42 +/- 2.96) showed significantly lower results than that of PAN cement (7.88 +/- 3.49) (p < 0.05). All cleansing protocols (4.29 +/- 2.17 to 5.82 +/- 2.5) showed significantly lower results than that of the control group (9.84 +/- 4.88) for PAN cement. For CSA cement, all cleansing protocols presented non-significant results (4.25 +/- 2.74 to 6.44 +/- 2.4 MPa) compared to control group (p > 0.05) expect cb method (3.42 +/- 1.47) (p < 0.05). Remnants of cements were detected on dentin surfaces in all groups at varying degrees. SEM showed that while using pumice-water slurry was the least effective for PAN, tungsten carbide bur was the most effective for both cements. All other methods showed similar cleansing efficacy. None of the cleansing protocols yielded to complete removal of resin cement rest on dentin upon recementation for both cements tested. (C) 2012 Elsevier Ltd. All rights reserved.
Evaluation the Effect of Different Antioxidants Applied After Bleaching on Teeth Color Stability
(Universidade Estadual Paulista, Institute of Science and Technology of Sao Jose dos Campos, 2020) Degirmenci, A.; Kara, E.; Degirmenci, B.U.; Ozcan, M.
Objective: Vital bleaching is a popular treatment option for discolored teeth; but at post-treatment stage, loss of adhesion is highly reported. Literature focused on antioxidant application for the answer of this issue. The aim of this study was to compare the effects of six different antioxidants on color stability of bleached teeth. Material and Methods: This study included total of 84 extracted intact non-carious lower incisors. 35% hydrogen peroxide was applied on the labial surfaces of specimens in accordance with manufacturer’s instructions. The bleached teeth were divided into 7 groups. No antioxidants were applied to the control group. For the experimental groups, the following antioxidants were applied for 10 minutes each: 5% proanthocyanidin, 5% sodium ascorbate, 5% lycopene, %5 green tea, %5 white tea and %5 α-tocopherol. CIE L*, a* and b* values of the teeth were measured by a spectrophotometer. One-way ANOVA was used to determine the differences among the groups. Multiple comparisons were examined with Tukey HSD. Results: The one-way ANOVA test revealed a statistically significant difference between the groups (p<0.005). Highest color change was observed in lycopene group and the lowest in green tea group. Conclusion: Proanthocyanidin, white tea and green tea could be considered as post-bleaching antioxidant alternatives based on their herbal nature. © 2020, Universidade Estadual Paulista, Institute of Science and Technology of Sao Jose dos Campos. All rights reserved.