Influence of Ortho Primer Morelli adhesion booster on orthodontic brackets shear bond strength

Abstract

OBJECTIVE: This work aimed at assessing the bond strength (AS), the site of the flaw and the relation between them and Ortho Primer Morelli® (OPM) adhesion optimizer. METHODS: Sixty test specimens, made out of bovine permanent lower incisors, were divided into three groups: TXT Primer (control), in which a conventional adhesive system was applied (primer and paste); OPM, in which TXT primer was replaced by OPM; and TXT without Primer, in which only TXT paste was used. A shear force was applied at a speed of 0,5 mm/min. Failure site was assessed by the Remaining Adhesion Index (RAI). RESULTS: Kruskal-Wallis demonstrated that OPM (8.54 ± 1.86 MPa) presented a statistically higher AS (p < 0.05) IF compared to TXT Primer (6.83 ± 2.05 MPa). There was no statistically significant difference (p > 0.05) between TXT with or without Primer (6.42 ± 2.12 MPa). Regarding the RAI, the K test demonstrated that TXT Primer and OPM (prevailing scores 2 and 3) showed higher values (p < 0.05) IF compared to TXT without Primer (prevailing scores 0 and 1). Spearman demonstrated that there was no correlation between AS and RAI (p > 0.05). CONCLUSION: OPM increases AS and presents the same bond failure location if compared to a conventional adhesive system; the use of the TXT adhesive system paste only was shown to have the same AS if compared to conventional systems, except it does not allow to predict the adhesive failure site; there is no correlation between AS and bond failure location, regardless of the use of any adhesion optimizer

Orthodontic bracket bonding without previous adhesive priming: A meta-regression analysis

“…Hence, the achievement of desirable shear strength does not depend on the requirement of adhesive resin wettability. This consideration may be valid for both as flowable, 24 orthodontic, 17 or restorative resins, since no significant differences in bond strength were found among them (P 5 .42), and this adhesive variable did not interfere with the ones included on the multivariate test. According to Shahabi et al, 21 another suggestion of adhesive resin application to protect enamel against debonding force 25 is not unanimous, owing to their findings that the application had no effect on the quality or quantity of cracks whether it was applied in one or two layers.…”

“…After bias risk analysis (Table 1), one study 11 was excluded due to its high risk of bias. Nine studies 2,3,8,[12][13][14][15][16][17] were included; descriptive data, random-effect means, confidence interval, and weight of each study are shown in Table 2. The lowest mean for bond strength in a group was 6.42 MPa; the highest value was 34.8 MPa, with 50% of the groups' means being lower than 11.0 MPa.…”

“…Other important variables cited in previous studies 8,17 were included solely for the univariate model. We included studies that used bovine or human teeth, with no significant difference between them.…”