Shear/peel bond strength of orthodontic attachments to moist and dry enamel

Evaluation of the effects of different composite materials and surface roughening techniques in bonding attachments of clear aligner on monolithic zirconia

OBJECTIVE

The aim of this study is to evaluate the bond strengths of two different composite types used in the production of clear aligner attachments on monolithic zirconia with three different surface roughening processes.

MATERIALS AND METHODS

Packable composite Filtek Z250 was used in one group (PC-G) and flowable composite Filtek Supreme Ultra Flowable was used in the other group (FC-G). PC-G and FC-G groups were also divided into three subgroups as diamond bur+silane (Group 1), 50 μm aluminium oxide (Al2 O3 ) sandblasting+silane (Group 2) and 110 μm Al2 O3 sandblasting+silane (Group 3). Scanning electron microscopy (SEM) analysis was performed. Clear aligner attachments were bonded to the monolithic zirconia specimens. Shear bond strength (SBS) values were measured. Statistical analysis was performed using two-way ANOVA and post-hoc Tukey's tests (P < .05).

RESULTS

The highest SBS value was found in PC-G sandblasted with 110 μm Al2 O3 (P ≤ .001). The etching method with 110 μm sandblasting showed high SBS values in both composite types. The lowest SBS value gave FC-G in diamond bur roughening (P ≤ .001).

CONCLUSIONS

For the bonding of clear aligner attachments on monolithic zirconia, roughening with 110 μm particle size sandblasting and the choice of packable composite could be recommended in terms of retention.

Comparative study of three composite materials in bonding attachments for clear aligners

OBJECTIVE

The aim of this study was to assess the operation time, shear bond strength, placement accuracy and wear resistance of 3 composite materials (Filtek Z350XT, Filtek Z350XT Flowable and SonicFill) that were used to make attachments for clear aligners.

SETTINGS AND SAMPLE POPULATION

Laboratory of Stomatology of Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. A total of 129 human mandibular premolars were collected, 69 of which were assigned to 3 groups (A1, B1 and C1). The remaining 60 teeth were divided into 3 groups (A2, B2 and C2).

METHODS

Z350XT composite resin was used in groups A1 and A2 to bond the attachments. Z350XT Flowable composite resin was used in groups B1 and B2. SonicFill composite resin was used in groups C1 and C2. The operation time, shear bond strength, the placement accuracy and wear volume loss of 3 composite materials were evaluated.

RESULTS

The operation time of Z350XT Flowable and SonicFill was shorter than Z350XT (P < .05). The shear bond strength of SonicFill was higher than Z350XT and Z350XT Flowable (P < .05). The SEM showed that the bonding interface of Z350XT and SonicFill was compact. The 3D deviation and volumetric change in the 3D designed attachments and the attachments after actual bonding of Z350XT Flowable were greater than that of Z350XT and SonicFill (P < .05). The wear volume loss of SonicFill and Z350XT was less than that of Z350XT Flowable (P < .05).

CONCLUSION

SonicFill seems to represent a suitable material for producing attachments, which optimized the property combination.

Effect of Adhesion Boosters on the Indirect Bonding with the Lingual Brackets: An In Vitro Study

Aims and Objectives:

To evaluate the influence of the two adhesion boosters (assure universal bonding resin and enhance adhesion booster) on the shear bond strengths of indirectly bonded lingual brackets.

Materials and Methods:

A total of 120 extracted human teeth were randomly divided into 3 groups (n = 40), each group contained equal number of anterior and posterior teeth (anterior = 20, posterior = 20), and their lingual surfaces were etched by using 37% phosphoric acid. The bracket was bonded indirectly without using adhesion booster in group 1 (control group). In group 2, the adhesion booster A (enhance adhesion booster) and adhesion booster B (assure universal bonding resin) in group 3 were applied, respectively, before the bonding. The universal testing machine was used to measure the maximum bond strength. Student’s t-test followed by the one-way analysis of variance was used to compare shear bond strength among the groups.

Results:

The shear bond strength was found to be highest in group 3, followed by group 2, and it was least in controls. There were highly significant differences statistically in shear bond strength among the groups 1, 2, and 3 ( P = .001).

Conclusion:

Shear bond strength was admissible in all the groups. The application of the assure universal bonding resin significantly increased the bond strength of lingual brackets in indirect bonding.

Shear bond strength of orthodontic attachments bonded to impacted teeth under in vivo and in vitro conditions

OBJECTIVES

To evaluate and compare the shear bond strength (SBS) of stainless steel and gold-plated attachments to impacted lower third molars in vivo and in vitro with a light-cured orthodontic resin.

SETTING AND SAMPLE POPULATION

Sixteen patients with bilaterally full soft tissue impaction of lower third molars were recruited on a voluntary basis from an oral and maxillofacial surgery department.

MATERIALS AND METHODS

A split-arch technique was used. Following surgical exposure of the crown, the tooth was luxated but not extracted. Then, two attachments (one stainless steel button and one gold-plated eyelet) were bonded to the labial enamel surface of the loosened tooth. Five minutes later, the luxated tooth was removed from its socket. In each patient, the impacted tooth on the other side was extracted, and attachments were bonded in vitro. The SBSs of the attachments were evaluated. For comparison, analysis of variance and multiple range tests were used (α = 0.05).

RESULTS

Statistically significant differences were evident in attachment adhesion to the impacted tooth surfaces among the four groups (p < 0.001). Superior SBS values were obtained for stainless steel button groups bonded in vitro. The mean bond strengths of the groups bonded in vitro were better than those of the same groups bonded in vivo.

CONCLUSIONS

Although the in vitro-bonded groups showed higher SBS values, adequate bond strength is possible with stainless steel buttons bonded in vivo.

Effect of adhesion boosters on indirect bracket bonding

OBJECTIVE

To determine the influence of two adhesion boosters on shear bond strength and on the bond failure location of indirectly bonded brackets.

MATERIALS AND METHODS

Sixty bovine incisors were randomly divided into three groups (n = 20), and their buccal faces were etched using 37% phosphoric acid. In group 1 (control), brackets were indirectly bonded using only Sondhi adhesive. In groups 2 and 3, the adhesion boosters Enhance Adhesion Booster and Assure Universal Bonding Resin, respectively, were applied before bonding with Sondhi. Maximum bond strength was measured with a universal testing machine, and the location of bond failure was evaluated using the Adhesive Remnant Index (ARI). One-way analysis of variance followed by the Tukey test (P < .05) was used to compare the shear bond strength among groups, and the differences in ARI scores were evaluated using the Kruskal-Wallis test (P < .05). The Pearson correlation coefficient was calculated to determine whether there was any correlation between bond strength and ARI scores.

RESULTS

The mean shear bond strength in group 3 was significantly higher (P < .01) than in the other groups. Evaluation of the locations of bond failure revealed differences (P < .05) among the three groups. There was a moderate correlation between bond strength and ARI scores within group 3 (r  =  0.5860, P < .01).

CONCLUSION

In vitro shear bond strength was acceptable in all groups. The use of the Assure adhesion booster significantly increased both the shear bond strength of indirectly bonded brackets and the amount of adhesive that remained on the enamel after bracket debonding.

In vitro shearing force testing of two seventh generation self-etching primers

OBJECTIVE

The purpose of this study was to evaluate the in vitro shearing force performance of orthodontic attachments using two self-etching primers (SEPs): iBOND and G-Bond.

DESIGN

In vitro, laboratory study.

MATERIAL AND METHODS

One hundred and eighty human molars were randomly divided into four groups and again into three sub-groups with 15 teeth each. Teeth were bonded with a stainless steel button (GAC International,Bohemia, NY, USA) using Transbond XT adhesive composite. The bonding agents were iBOND, G-Bond, Transbond Plus SEP and Transbond XT primer. Shearing force tests were carried out immediately, and at 24 hours and 3 months using a universal testing machine. Force to debond (N) and Adhesive Remnant Index (ARI) scores were evaluated and compared.

RESULTS

Transbond XT primer required a higher immediate (P<0·05)force to debond when compared to the Transbond Plus SEP, iBOND and G-Bond.After 24 hours, mean force to debond for Transbond XT primer and Transbond Plus SEP showed significant increases. At 3 months, all four bonding agents demonstrated force levels to debond that were not significantly different from one another. Furthermore, comparison of ARI scores indicated a significant difference between the groups at all time points.

CONCLUSIONS

iBOND and G-Bond may well sufficiently with stand the alignment and occlusal forces imparted by light archwires during immediate archwire tie-in and over the initial levelling and alignment phase.

Effect of Saliva Contamination and Decontamination on Bovine Enamel Bond Strength of Four Self-etching Adhesives

Salivary contamination before and after priming could significantly reduce the enamel bond strength of self-etching adhesives. Proper isolation should be performed before and during application of the adhesives and placement of the resin composite. Thorough water-spraying could significantly improve the μTBS of saliva-contaminated enamel.

Bond strength of resin-resin interfaces contaminated with saliva and submitted to different surface treatments

The purpose of this study was to investigate the effect of different surface treatments on shear bond strength of saliva-contaminated resin-resin interfaces. Flat resin surfaces were fabricated. In the control group, no contamination or surface treatment was performed. The resin surfaces of the experimental groups were contaminated with saliva and air-dried, and then submitted to: (G1) rinsing with water and drying; (G2) application of an adhesive system; (G3) rinsing and drying, abrasion with finishing disks, etching and application of adhesive system; (G4) rinsing and drying, etching, application of silane and adhesive system. Resin cylinders were placed over the treated surfaces. The specimens were stored in water or ethanol. Shear bond strength tests were performed and the mode of failure was evaluated. Data were submitted to two-way ANOVA and Dunnett T3 test. Contamination of resin-resin interfaces with saliva significantly reduced shear strength, especially after prolonged storage (p<0.05). Similar values to the original bond strength were obtained after abrasion and application of adhesive (G3) or etching and application of silane and adhesive (G4). If contamination occurs, a surface treatment is required to guarantee an adequate interaction between the resin increments.

Water and saliva contamination effect on shear bond strength of brackets bonded with a moisture-tolerant light cure system

OBJECTIVE

To evaluate the effects of water and saliva contamination on shear bond strength of brackets bonded with a moisture-tolerant light cure system.

MATERIALS AND METHODS

Brackets were bonded to 240 bovine lower incisors divided into 12 groups. Four bonding procedures were evaluated, including (1) TSEP/Transbond XT, (2) TMIP/ Transbond XT, (3) TSEP/Transbond PLUS, and (4) TMIP/Transbond PLUS, each under three different bonding conditions: without contamination, with water contamination, and with saliva contamination. Shear bond strength was measured with a universal testing machine. The adhesive remnant on the teeth was quantified with the use of image analyzing equipment.

RESULTS

Without contamination, bond strengths for the four procedures were similar (P > .05). TSEP/Tranbond PLUS and TMIP/Transbond PLUS left significantly less adhesive on the teeth after debonding than TSEP/Transbond XT and TMIP/Transbond XT (P < .008). Bond strength and adhesive remaining for TMIP/Transbond XT contaminated with water or saliva showed significantly worse performance than the other procedures evaluated (P < .008). Contamination (with water or saliva) did not affect either bond strength or adhesive remaining on the teeth for TSEP/ Transbond XT, TSEP/Transbond PLUS, or TMIP/Transbond PLUS (P > .017), although for TMIP/ Transbond XT, both variables showed significant reductions after contamination (P < .017).

CONCLUSION

TSEP/Transbond PLUS, TMIP/Transbond PLUS, and TSEP/Transbond XT showed greater tolerance to wet conditions than was shown by TMIP/Transbond XT.