Residents’ journal review

Does AcceleDent accelerate full-fixed appliance treatment?

Woodhouse NR, DiBiase AT, Johnson N, Slipper C, Grant J, Alsaleh M, et al. Supplemental vibrational force during orthodontic alignment: A randomized trial. J Dent Res 2014;94:682-9

Application of intermittent vibrational force to the dentition has been proposed to increase the rate of orthodontic tooth movement. AcceleDent (OrthoAccel Technologies, Bellaire, Tex) is a hands-free device that produces 30 Hz of vibrational frequency and 0.2N of force, and is to be used 20 minutes per day. These authors tested the effectiveness of AcceleDent in accelerating orthodontic tooth movement using full-fixed appliances in a prospective 3-arm parallel-group randomized control trial. Inclusion criteria for the subjects were less than 20 years of age, permanent dentition, and mandibular first premolars extracted before bonding. All subjects had 6-week data collection intervals. The times to achieve initial and final alignments were documented. The rates of alignment, measured using Little’s irregularity index, were calculated as the difference in the index at baseline compared with initial or final alignment divided by the number of days between measurements. The authors concluded that supplemental vibrational force did not significantly increase the rates of initial and overall alignment with fixed appliances, and that initial irregularity was the greatest factor determining rates. Although this was a well-designed study, several weaknesses should be noted. First, the authors found that the timer of the “classic” AcceleDent devices was unreliable. Second, Little’s irregularity index is subjective and may not accurately estimate changes in tooth alignment. Third, alignments were evaluated every 6 weeks; therefore, periods of increased orthodontic tooth movement during this span could have been missed. Further prospective studies are required to control for all the confounding variables to confirm and support these results. It may be of interest to determine the effectiveness of AcceleDent with clear aligner therapy, as well as its potential roles in decreasing patient discomfort and root resorption. Such studies are required to ensure the scientific validity of new appliances available for orthodontic treatment.

Reviewed by Amir Dadgar-Yeganeh

Is primer required for orthodontic bonding?

Nandhra SS, Littlewood SJ, Houghton N, Luther F, Prabhu J, Munyombwe T, et al. Do we need primer for orthodontic bonding? A randomized trial. Eur J Orthod 2015;37:147-55

When bonding orthodontic brackets, the purpose of using primer or unfilled resin is to enhance the bond strength via enamel surface penetration. Despite its intended purpose, previous in-vivo studies have shown that the tensile bond strengths with and without a primer were comparable, and that primer may be an unnecessary step in bonding orthodontic brackets to teeth. The objective of this study was to further evaluate whether primer is required for successful bonding of brackets to teeth. Toward this end, the authors studied differences in bracket failure rates over 12 months with and without primer, bonding time per bracket, and the type of bonding failures using the adhesive remnant index. Ninety-two orthodontic patients were randomly assigned to 2 groups for full-fixed appliance treatment. Failure rates were determined to be 11.1% with primer and 15.8% without primer. The mean bracket-bonding time difference was 4 seconds per bracket. However, the differences between the failure rates or bracket bonding time were not significant. The adhesive remnant index showed that when bonding without primers, bracket failures were significantly more likely to occur between the enamel surface and the composite rather than between the composite and the bracket surface. This study supports the idea that primer may be an unnecessary step in the bonding process. The implication of this conclusion is significant in that the elimination of the priming step may reduce financial costs, partly by reducing chair time. However, further studies involving multiple operators and evaluators are strongly recommended.

Reviewed by Stephan Yoon

Is primer required for orthodontic bonding?

Nandhra SS, Littlewood SJ, Houghton N, Luther F, Prabhu J, Munyombwe T, et al. Do we need primer for orthodontic bonding? A randomized trial. Eur J Orthod 2015;37:147-55

When bonding orthodontic brackets, the purpose of using primer or unfilled resin is to enhance the bond strength via enamel surface penetration. Despite its intended purpose, previous in-vivo studies have shown that the tensile bond strengths with and without a primer were comparable, and that primer may be an unnecessary step in bonding orthodontic brackets to teeth. The objective of this study was to further evaluate whether primer is required for successful bonding of brackets to teeth. Toward this end, the authors studied differences in bracket failure rates over 12 months with and without primer, bonding time per bracket, and the type of bonding failures using the adhesive remnant index. Ninety-two orthodontic patients were randomly assigned to 2 groups for full-fixed appliance treatment. Failure rates were determined to be 11.1% with primer and 15.8% without primer. The mean bracket-bonding time difference was 4 seconds per bracket. However, the differences between the failure rates or bracket bonding time were not significant. The adhesive remnant index showed that when bonding without primers, bracket failures were significantly more likely to occur between the enamel surface and the composite rather than between the composite and the bracket surface. This study supports the idea that primer may be an unnecessary step in the bonding process. The implication of this conclusion is significant in that the elimination of the priming step may reduce financial costs, partly by reducing chair time. However, further studies involving multiple operators and evaluators are strongly recommended.

Reviewed by Stephan Yoon

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Apr 6, 2017 | Posted by in Orthodontics | Comments Off on Residents’ journal review
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