Shear Bond Strength Of Self-etch Research Articles

An In Vitro Study to Compare the Shear Bond Strength of Orthodontic Brackets Bonded to Permanent Teeth by Using Conventional Acid-Etching and Self-Etching Primers

Objectives: The objective of the present study was to evaluate and compare the bond strength of orthodontic brackets bonded to permanent teeth with a conventional acid-etching and self-etching primer systems. Also, the study aims to evaluate the mode of bond failure after debonding the brackets. Materials and Methods: It was an experimental study. Fifty extracted permanent premolars were collected, checked, and cleaned. Teeth were split equally into two groups, group A and B. Orthodontic brackets were bonded using conventional acid-etching and self-etching primer systems for group A and B, respectively. Shear bond strength (SBS) was measured with a universal testing machine, and the mode of bracket-adhesive failure was determined by using adhesive remnant index (ARI). Data were analyzed with a statistical software. Independent sample t-test was used to compare the SBS and Mann–Whitney U test was used to assess whether there is a significant difference of ARI score between the groups. Results: Although the SBS with self-etching primer was within clinically acceptable range, the overall mean SBS for group A (14.71 MPa) was significantly greater than group B (9.24 MPa) (P = 0.024). There was no significant difference in ARI scores between conventional acid-etching and self-etching groups (P = 0.801). Conclusion: The SBS of the conventional acid-etching was significantly higher than the self-etching primer. The SBS of self-etch was within the acceptable range to withstand the forces of mastication. The majority of the brackets recorded ARI score of 1 indicating a cohesive failure with no significant difference between acid-etch and self-etch groups.

Influence of Er: Yag Laser on Shear Bond Strength of Self-etching Adhesives to Bovine Enamel: In vitro Study

ABSTRACT Purpose The aim of this study was to evaluate the influence of the enamel treatment with Er:YAG laser on the bond strength of self-etching adhesives. Materials and methods One-hundred bovine incisors were ground to obtain flat enamel surfaces. The bond area was delimited with 3 mm diameter adhesive tape. Specimens were divided in two groups: Group L: Enamel surface received Er:YAG laser application (Kavo KEY 3) at 300 mJ/6 Hz in sweeping mode for 30 seconds; Group N: Enamel surface received no additional treatment. Each group was divided into five subgroups according to self-etching adhesive: S&E (Self & Etch), FB (Futurabond NR), XE (Xeno III), OU (One-Up bond F), CL (Clearfil SE Bond). Cylinders of Z250 composite were fabricated on the bonding area using a teflon matrix. The teeth were stored in water at 37°C/ 24 hours and submitted to shear testing at a speed of 1 mm/min. Results The results were analyzed by two-way ANOVA and Tukey's test, obtaining p-value = 0.001. The mean values (±SD) in MPa for each group/subgroup were: N/FB—19.65(±3.87)a; N/CL—19.55(±3.78)a; N/OU—15.57(±2.85)ab; N/XE—15.32(±4.00)b; L/CL— 13.91(±2.54)b; L/OU—13.16(±2.17)bc; L/XE—9.74(±1.65)cd; N/S&E—8.83(±2.63)d; L/FB—8.30(±2.27)d; L/S&E—6.56(±1.55)d. Conclusion It was concluded that the enamel surface treatment with Er:YAG laser reduced the bond strength significantly for most of the self-etching adhesives tested.

Priming time and etching effect on shear bond strength of self-etching adhesive

자가산부식 접착제 (self-etching primer)는 법랑질과 상아질을 동시에 산부식과 프라이머 처리를 함으로 임상 시술 시간을 단축시킬 뿐만 아니라, 임상과정 중 발생할 수 있는 술자의 실수 및 타액등에 의한 오염의 가능성을 줄일 수 있 는 장점을 가지고 있다. 그러나 약산을 이용한 산부식법이 법랑질에 대해 탈회효과 및 접착강도에 있어 논란이 되고 있 다. 이에 본 연구에서는 인산을 이용한 추가적인 산부식 및 자가산부식 접착제의 적용시간을 달리할 경우 법랑질에 대한 접착강도의 변화를 알아보고자 하였다. 135개의 발거한 우치의 법랑질 면을 #600 사포로 연마한 후 9개의 군으로 분류하였다. 각 군은 부가적인 32% 인산 을 처리하지 않은 군 (1~3군), 15초간 처리한 군 (4~6군), 60초간 처리한 군 (7~9군)으로 나누고, 이를 다시 Clearfil SE Bond의 프라이머로 5초 (1, 4, 7군), 20초 (2, 5, 8군), 60초 (3, 6, 9군)간 처리한 군으로 분류하였다. 접착제 처리한 면에 Clearfil AP-X 복합레진을 접착하고 24시간 경과 후 전단응력 강도를 측정하였다. 결과는 Oneway ANOVA 처리 후 Duncan’s multiple range test로 사후검증하였다. 동일한 자가산부식 프라이머 처리 시간을 가진 군에서 산 부식을 한 경우가 그렇지 않은 군에 비해 높은 접착강도를 나타내었으며 인산부식 시간의 차이에 의한 영향은 없었다 (1 < 4,7군/ 2 < 5,8군/ 3 < 6,9군). 자가산부식제의 프라이머 적용 시간에 의한 효과는 1군 (5초 적용)을 제외한 나머지 군의 경우 동일한 인산 처리군에 서는 차이가 없는 것으로 나타났다 (1군 < 2, 3군/ 4 = 5 = 6군/ 7 = 8 = 9군). Clearfil SE Bond 접착제의 법랑질에 대한 접착강도는 부가적인 산부식을 통하여 증가시킬 수 있으며 프라이머의 적 용 시간에 의한 효과는 제조자의 지시에 의한 시간 이상 적용할 경우 차이가 없는 것으로 나타났다. [J Kor Acad Cons Dent 29(2):185-190, 2004]