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 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

Microleakage and scanning electron microscopy evaluation of all-in-one self-etch adhesives and their respective nanocomposites prepared by erbium:yttrium-aluminum-garnet laser and bur

The aim of this study was to evaluate the microleakage of all-in-one self-etch adhesives and their respective nanocomposites in class V cavities prepared by erbium:yttrium-aluminum-garnet (Er:YAG) laser and bur. Class V cavities were prepared on both buccal and lingual surfaces of 72 premolars by Er:YAG laser or bur and divided into six groups (n = 24). The occlusal margins were enamel and the cervical margins were cementum. The groups were as follows: group 1 Er:YAG laser preparation (E) + Xeno V (X) + CeramX (C); group 2 bur preparation (B) + X + C; group 3 E + AdheSE One (A) + Tetric EvoCeram (T); group 4 B + A + T; group 5 E + Clearfil S3 Bond (CSB) + Clearfil Majesty Esthetic (CME); group 6 B + CSB + CME. All teeth were stored in distilled water at 37A degrees C for 24 h, then thermocycled 500 times (5-55A degrees C). Ten teeth from each group were chosen for the microleakage investigation and two teeth for the scanning electron microscopy (SEM) evaluation. The teeth that were prepared for the microleakage test were immersed in 0.5% basic fuchsin dye for 24 h. After immersion, 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). SEM observations of restorative material-dentin interfaces seemed to correspond with those of the microleakage test. Microleakage at the cervical interfaces was greater than that at the occlusal interfaces. Er:YAG laser-prepared class V cavities yielded more microleakage in occlusal margins with all-in-one self-etch adhesives and the respective manufacturer's nanocomposites

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). 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

Bond Strength of Orthodontic Brackets Bonded to Enamel with a Self-Etching Primer After Bleaching and Desensitizer Application

Objective: The aim of this study was to compare the shear bond strengths (SBS) of orthodontic brackets bonded to enamel with a self-etching primer after bleaching, desensitizer application and combined treatment. Methods: Forty-eight premolars were randomly divided into four groups, each with n = 12 premolar samples. The four groups were; Group1: 15% hydrogen-peroxide office bleaching agent (Illumine Office-IO), Group 2: IO + BisBlock Oxalate Dentin-Desensitizer, Group 3: Bis Block Oxalate Dentin-Desensitizer, Group 4: No treatment (control). Twenty-four hours after bonding, the specimens were tested in SBS at a crosshead speed of 5 mm/min until the brackets debonded. The failure mode of the brackets was determined by a modified adhesive remnant index. Results: Bleaching, bleaching and desensitizer treatment, and desensitizer treatment alone all significantly reduced SBS of the orthodontic brackets (p = 0.001). No statistically significant difference was found between Group 1, Group 2 and Group 3 (Group 1-Group 2, p = 0.564; Group 1-Group 3, p = 0.371; Group 2-Group 3, p = 0.133). The predominant mode of failure for the treatment groups (Group1, Group 2 and Group 3) was at the enamel-adhesive interface leaving 100% of the adhesive on the bracket base. Conclusions: Bleaching and desensitizer treatment should be delayed until the completion of orthodontic treatment. (Korean J Orthod 2010;40(5): 342-348)WoSScopu