Effect of radiotherapy on the microleakage of adhesive systems.
OBJECTIVE
The aim of this in vitro study was to evaluate the effect of radiotherapy on the microleakage of three adhesive systems: a one-step self-etching, a two-step self-etching, and an etch-and-rinse system.


METHODS
Box-shaped Class V cavity preparations were prepared on the buccal surfaces of 84 extracted human molars. The molars were randomly assigned into 6 groups (n = 14) according to the irradiation and adhesive system as follows: G1, Clearfil S3 Bond (irradiated); G2, Clearfil SE Bond (irradiated); G3, Prime & Bond NT (irradiated); G4, Clearfil S3 Bond (nonirradiated); G5, Clearfil SE Bond (nonirradiated); and G6, Prime & Bond NT (nonirradiated). The cavities were restored with composite resin (Filtek Z 250). After restoration of the samples, a total dose of 60 Gy was delivered in 2 Gy/d fractions for 5 days per week for 6 weeks for the related groups. All specimens were thermocycled for 200 cycles between 5 degrees C and 55 degrees C using a dwell time of 60 s in each bath and then placed in 0.5% basic fuchsin solution for 24 h at room temperature. Specimens were then rinsed and sectioned; the dye penetration at the enamel and dentin margins was examined using a stereomicroscope, and a score of 0 to 3 was assigned. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U-tests.


RESULTS
No statistically significant difference existed between the irradiated and nonirradiated groups (p > 0.05). Significant differences in microleakage were observed between enamel and dentin (p < 0.01). The microleakage at the dentin margins was greater than at the enamel margins. Prime & Bond NT revealed statistically significantly (p < 0.05) higher leakage scores in dentin than did ClearfilS3 Bond and Clearfil SE Bond.


CONCLUSIONS
Within the limitations of this study, irradiation application did not affect the microleakage of dental adhesive systems.
Bulucu
Bilinç
B
Department of Operative Dentistry, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey. bbulucu@omu.edu.tr
Avsar
Aysun
A
Demiryürek
Ebru Ozsezer
EO
Yesilyurt
Cemal
C
D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D003737:Dental Cavity Preparation / Q000145:classification; D003738:Dental Cements / Q000737:chemistry / Q000528:radiation effects*; D003743:Dental Enamel / Q000528:radiation effects / Q000648:ultrastructure; D003763:Dental Leakage / Q000145:classification*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000528:radiation effects / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000528:radiation effects; D006801:Humans; D008422:Materials Testing; D008963:Molar / Q000528:radiation effects* / Q000648:ultrastructure; D011109:Polymethacrylic Acids / Q000737:chemistry / Q000528:radiation effects; D011829:Radiation Dosage; D011878:Radiotherapy; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects; D012394:Rosaniline Dyes; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
C505694:Clearfil S3 Bond; C438313:Clearfil SE Bond; D004396:Coloring Agents; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D019279:Resin Cements; D012394:Rosaniline Dyes; C025485:basic fuchsin