Bond strength of two techniques for bonding lingual orthodontic retainer

AIM: The aim of this study was to compare the shear bond strength of two techniques for bonding lingual orthodontic retainer; the chairside modified bonding technique introduced by Al-Emran and Hashim, and the chairside manual bonding technique currently used in orthodontic practice. MATERIALS AND METHODS: Sixty-four extracted cariesfree premolars were divided into two equal groups. Group A represented the manual bonding technique and Group B represented the modified bonding technique. The shear bond strength was tested using the InstronTM machine. Descriptive statistical analysis and independent two-samples t test were employed to compare the data. RESULTS: The modified bonding technique (Group B) showed significantly higher tolerance to the applied load before the bond failure occurred (P=0.02). Also, Group B showed significantly higher degree of displacement of the bonded wire before bond failure (P= 0.05). Manual bonding technique (Group A) showed 19%, 43.5% and 37.5% of Types I, II and III bond failure respectively, whereas modified bonding technique (Group B) showed 69%, 6% and 25% of similar type of bond failure respectively. CONCLUSIONS: For the two bonding techniques examined in this study, the modified bonding technique showed higher shear bond strength compared to the manual bonding technique, and was recommended as a technique for bonding fixed lingual retainer for post-treatment retention phase.