In vitro comparison of wear of three orthodontic bite materials and opposing enamel.

OBJECTIVE: Orthodontic bite turbos are used to separate the maxillary and mandibular arch when disocclusion is needed for brackets placement or extrusion of teeth. Bite turbos should have adequate wear resistance to maintain disocclusion but also avoid abrasion of the opposing enamel. The objective of this study was to measure the wear of three materials used as bite turbos and opposing enamel wear. MATERIALS AND METHODS: 10mmx8mmx4mm specimens (n=8) of TransbondLR (3M) Transbond Plus (3M) and Triad(R)gel (Dentsply) were prepared in silicone molds. Cusps of extracted premolars were prepared to a standard cone shape. Extracted maxillary incisors were used as reference for flat enamel surfaces. The experiments were performed on the modified UAB wear testing device at 20N for 200,000 cycles at 1Hz. All surfaces were scanned with a non-contact profilometer at 10micron resolution. Volumetric wear was measured with superimposition software and data analysed with one-way ANOVA and Tukey post-hoc. RESULTS: Significant differences were seen in the wear of materials and opposing enamels (P<.01). Material wear ranked: Triad(R)gel (.878+/-.196mm(3))>Transbond Plus (.317+/-.062mm(3))>Transbond LR (.136+/-.027mm(3))>Enamel (.053+/-.04mm(3)). Opposing enamel ranked: Transbond LR (.158+/-.086mm(3))=Enamel (.128+/-.035mm(3))=Transbond Plus (.126+/-.025mm(3))>Triad(R)gel (.039+/-.008mm(3)). CONCLUSIONS: All bite turbo materials wore more than natural enamel but caused equal or less wear to opposing enamel than tooth-tooth contact. Triad(R)gel underwent 2.5x and 6x the wear of Transbond Plus and Transbond LR respectively. The bite turbo material used may be selected based on preference for longevity.