Comparison of Bonding Failure Rates of Fixed Lingual Mandibular Retainers in a French Sample Aged 11 or Older, Comparing Prior Enamel Sandblasting With Conventional Pumice Polishing

At the completion of orthodontic treatment, the position of the mandibular canines and incisors is being maintained on a routine basis by bonding a multi-braided wire retainer onto their lingual surfaces. One of the adverse events that might occur with time is the debonding of the wire from one or several lower anterior teeth . This event which can unfortunately get unnoticed by the patient can lead to unwanted tooth displacement. When the practionner detects such a debonding, he has to go through a laborious and lengthy procedure to rebond the wire. When on the other hand the patient notices himself such a debonding, he is to call in emergency his practitioner to get his retainer repaired. This leads to emergency visits that are susceptible to affect adversely his timetable. The prevalence of these bonding failures is estimated at 37% at 18 month follow-ups. It has been reported that with prior enamel sandblasting, bonding failure rate is reduced to 8% at 24 month follow-ups. However, no study has reported yet the debonding rate of lower fixed, comparing wires that have been bonded after prior enamel pumicing to those that were put in place after prior enamel sandblasting.

The expected result of this trial is a significantly decrease in bonding failure rate of mandibular lingual retainer when enamel surfaces are initially sandblasted compared to the ones which are pumiced. This reduction would lower the risk of unwanted tooth movement of mandibular incisors and canines after orthodontic treatment and decrease the number of emergency appointments for the patient and the practitioner.