جستجوی مقالات مرتبط با کلیدواژه « adhesive remnant index » در نشریات گروه « پزشکی »

Patients undergoing fixed orthodontic treatments face a higher risk of white spot lesions (WSLs) due to difficulties in effective plaque control. Several preventive measures provide remineralization and antibacterial benefits that reduce WSLs. These measures, while protective, may adversely affect the shear bond strength (SBS) of orthodontic brackets, potentially leading to bracket debonding and impacting overall treatment effectiveness. This study comparatively evaluated the effects of pretreatments with fluoride varnish, chlorhexidine fluoride mouthwash (CHXF), and fluoridated casein phosphopeptide-amorphous calcium phosphate (CPP-ACPF) on the shear bond strength (SBS) of orthodontic brackets bonded with GC Ortho Connect composite resin.

Sixty extracted premolar teeth were randomly divided into four groups. The first group was the control without pretreatment, and the second to fourth groups were pretreated with 5% fluoride varnish for 4 minutes, with a CHXF for 7 days, and with CPP-ACPF for 3 minutes, respectively.  Specimens were subsequently tested for the SBS in a universal testing machine. Each tooth was visually examined and magnified (×10) using a Nikon SMZ800 to evaluate the adhesive remnant index (ARI).One-way ANOVA, followed by post hoc Tukey tests used for statistical analysis. The significance level was set at P<0.05.

Evaluation of SBS showed no significant differences between the control, chlorhexidine fluoride mouthwash, and CPP-ACPF groups (P>0.05). However, the SBS of the fluoride varnish group was significantly lower than in other groups (P<0.05). Adhesive remnant index (ARI) scores did not show significant differences between the four groups (P=0.057).

The results showed that the SBS of the brackets in the CPP-ACPF paste, CHXF, and fluoride varnish groups were higher than the appropriate range for orthodontic purposes.

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.

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.

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).

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.