Effect of curing modes on knoop hardness and microtensile bond strength of two dentin adhesives
10.3760/cma.j.issn.1002-0098.2013.01.012
- VernacularTitle:光照模式对两种牙本质粘接剂硬度和微拉伸强度的影响
- Author:
Wen-Jia WEI
1
;
Xiang-Feng MENG
;
Zheng HUANG
;
Xia LIU
Author Information
1. 210008,南京大学口腔医学院·南京市口腔医院修复科
- Keywords:
Dentin-bonding agents;
Hardness;
Tensile strength;
Light
- From:
Chinese Journal of Stomatology
2013;48(1):45-49
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluated the effect of curing modes and light-cure times on knoop hardness(KH) and microtensile bond strength (μTBS) of dentin adhesives in vitro.Methods Twenty molars were made into 80 dentin slices (about 1 mm thick).The dentin slices were prepared with an etch & rinse adhesive A(ONE-STEP PLUS)and a self-etch adhesive B (Clearfil SE Bond),and light-cured respectively under fast mode,i.e.1250 mW/cm2 light intensity for 10 s,15 s,20 s,and ramp mode(soft start curing mode),i.e.initial 0 mW/cm2 gradually increasing to 1250 mW/cm2 in first 10 s,then steady for the next 10 s.The prepared dentin slices were kept in dark dry room for 24 h at 37 ℃,and KH were tested.The other 40 molars were flattened to expose coronal dentin,prepared with adhesives as above.Then the prepared teeth were restored with resin composites incrementally and cured under fast mode.The restored teeth were stored in water for 24 h at 37 ℃,and slowly sectioned to obtain multiple bonded beams.After 7 d water-storage,the samples received microtensile bond test,and the failure models of beams were observed under a stereomicroscope.Data were analyzed by ANOVA and LSD test (α =0.05).Results No statistical difference in KH [(28.20 ± 5.36),(29.13 ± 5.60),(28.13 ± 4.40),(27.06 ± 3.77) MPa] and μTBS [(22.30 ± 5.07),(22.73 ± 6.59),(26.32 ± 6.17),(25.67 ± 4.31) MPa] of adhesive A were found between four curing conditions(fast mode for 10 s,15 s,20 s and ramp mode for 20 s) (P ＞0.05).In adhesive B,KH of Fast 20 s [(28.23 ± 3.67) MPa] were significantly higher than those of Fast 10 s [(14.15 ± 2.24) MPa] and Fast 15 s [(17.63 ± 2.17) MPa] (P ＜ 0.05).The μTBS of Fast 20 s [(42.52 ± 3.59) MPa] were significantly higher than those of Fast 10 s [(24.21 ± 3.60) MPa],Fast 15 s [(22.25 ± 4.16) MPa] and Ramp 20 s[(31.12 ±5.40) MPa] (P ＜0.05).In Fast 20 s and Ramp 20 s modes,there were no statistical difference in KH of adhesive A and B,while μTBS of adhesive B were higher than that of adhesive A(P ＜ O.05).Conclusions As for different type dentin adhesives,the appropriate curing time in fast mode is different,and ramp mode (soft start curing mode) has no advantage over fast mode.
