Comparison of Efficiency and Effectiveness of Two Types of Bonded Orthodontic Retainers: an RCT.

Comparson of efficiency and effectiveness of twisted/coaxial and linked retainers, placed under relative versus absolute isolation.

The domain of orthodontic retention is controversial. Orthodontic retention is the final step in an orthodontic procedure, and is performed after removal of the orthodontic appliance. Its goal is to prevent the relapse in occlusion or positioning of the teeth. Every patient will need some form of retention to maintain the ideal result. The bonded retainer is frequently used in the lower incisor region. It is capable to prevent relapse of orthodontic treatment but prevents tertiary crowding as well. Advantages of fixed retainers are in general no need for compliance and optimal aesthetics. The retention wire can stay in place for many years. Currently, there is a tendency towards lifelong retention. Disadvantages are more plaque and calculus accumulation, and possibly a poorer periodontal index. Many types of bonded retainers with different properties could be bonded, each with different effects on periodontal health, potentially a different ability to maintain alignment, and different amounts of failure. Different types of failure of fixed bonded retainers are possible. When the retainer does not stay in place and is debonded, this is is described as failure. It is also possible the retainer maintains bonded but shows unwanted tooth movement in the bonded teeth. This can also be described as a failure. Bonding of the retention wire is a technique sensitive process. Correct and passive bonding could prevent debonding of the retainers. To eliminate moisture in the bonding process, it is possible to place a rubberdam before bonding the retainer. One aim of this study is to compare two types of bonded retainer: the standard coaxial or twisted retainer. The other aim is to compare two bonding protocols with and without rubberdam isolation Two general PICO questions can be formulated: In an orthodontic patient (P), will fixed retention with a Ortho-flextech tm (Reliance orthodontic products, Itasca III, USA) (I) as compared to a 0.0195 in dead-soft coaxial wire (Respond; Ormco, Orange, Calif). (C) result in a more effective or efficient retention treatment (O)? In an orthodontic patient (P), will placement of the retainer with rubber dam (I) result in less debonding (O) as compared to relative isolation with cotton rolls (C)? Efficiency: is the procedure faster or cheaper than the alternative? Effectiveness: is the procedure better in maintaining the end result of treatment than the alternative? Are there less biomechanical or biological side effects?

Orthodontic retainers, Isolation, Bonding, Twistflex retainer, Coaxial retainer, OrthoflexTech retainer, Fixed retainer

Stability of treatment. The index measures the distance, in millimetres, between the contact points of crooked teeth, and then adds them together. Therefore,the Irregularity Index is the sum of all the displaced contacts between the anterior teeth (canine to canine)

Possible activation (unwanted tooth movement possible torque differences) is checked after treatment.

Inclusion Criteria: Fixed orthodontic appliances upper and lower jaw Patient stays for 2 years in Belgium Parents consent Proper oral hygiene Exclusion Criteria: Orthognathic surgery Craniofacial disorders Cleft lip palate patients Orthodontic treatment without fixed appliances Extra retention other than bonded wire in the lower jaw

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