The Effect of Volatile Oils on De-Bonding of Polycarbonate Bracket Reinforced with Ceramic Filler: A Quantitative Study (Part 1)

Introduction: The introduction of esthetic brackets is a new clinical approach in the field of orthodontics. Two main types of esthetic brackets have been developed and became widely available; the polycarbonate brackets, and the ceramic brackets. Both types have faced two significant de-bonding problems: (1) enamel and bracket fracture. The two problems have been well documented and continue to be of concern to clinicians. Aim: The aim of this in vitro study was to evaluate quantitatively the effect of three volatile oils and their combinations on the de-bonding of ceramic brackets. Material and Method: Polycarbonate brackets reinforced with ceramic filler were bonded to one hundred and eighty (180) sound extracted human premolars using Transbond XT light curing adhesive. The teeth were then distributed into the following groups according to the type of volatile oil and period of application: clove oil (5 & 30 minutes), peppermint oil (5 & 30 minutes), Black seed volatile oil (5 & 30 minutes), and mixture of peppermint + Black seed volatile oils (5 & 30 minutes) in addition to control group. The brackets were then de-bonded using the Instron Universal Testing Machine and the de-bonding force was recorded for each type of the volatile oils in different times of application. Result: The result revealed that the Black seed volatile oil gave the lowest de-bonding force in 5 minutes and 30 minutes of application whereas the mixture of the Black seed oil + peppermint oils gave the highest force in both time of application. Further, the peppermint oil application for 5-minute was found to be in the second rank whereas the Clove oil was in the third rank. Furthermore, in the 30 minutes of application the Clove oil was in the second rank whereas the peppermint was found to be in the third rank and the combination of Black seed oil + peppermint oil shows the highest debonding force. Conclusion: Despite the limitation of the present study result, an assumption has been drawn from the results obtained that (1) the 5- minutes of black seed or peppermint volatile oils application can be considered the best debonding agent compared to the other volatile oils; (2) the clove oil can be used after de-bonding to facilitate the final cleansing-up of enamel surface. To confirm the latter assumption, further investigations are needed.