Comparative analysis of anchorage systems for micro implant orthodontics (original) (raw)

2010, Progress in Orthodontics

The study analysed twelve anchorage systems based on micro implants in terms of their bio-mechanical properties and appraised their actual clinical effectiveness. Materials and methods: The analysed micro implants had data provided by the manufacturers or extracted from articles published in specialised journals. The parameters taken into account were: material, surface treatment, head type, length, diameter, neck length, filleted self drilling or self tapping surface, applicable orthodontic forces, possibility of immediate loading, and device removal. Results: Material Grade 5 titanium, titanium alloy (TiAl6V4), surgical steel; surfaces: smooth, sand-blasted and acid etched; head type: bracket, conic with button, round, hexagonal, button with cross cuts, double melted sphere; lengths: between 8.0 to14 mm; diameters: between 1.2 to 2.0 mms; neck lengths: inferior to 1.5 mm and superior to 2.0 mm; filleted portion: self tapping and/or self drilling; applicable orthodontic forces: up to 500 g, possibility of immediate loading, device removal, possibility to use in growing patients. Discussion: The most widely used material was TiAl6V4; most of the surfaces were smooth; the most commonly used head type was the bracket; the most often produced length was the "short" one (8.0-9.9 mm), the most demanded diameter the "smaller" one (1.2-1.4 mms); six systems out of eleven had micro implants with "extra" and "standard" necks; only 3 systems out of eleven produced "non self drilling"devices; all the micro implants analysed were able to withstand orthodontic forces between 150 g and 350 g; all devices were suitable for "immediate loading"; all micro implants had to be removed; all micro implants could be used in growing patients. Conclusions: The comparative analysis showed that micro implants could be used as valid anchorage systems, if dental anchorage was insufficient either in qualitative terms (i.e. parodontal problems) or in quantitative terms (i.e. few dental elements remaining), and in all those situations of limited patient compliance.