Effects of Composite Attachments on Orthodontic Clear Aligners Therapy: A Systematic Review

This systematic review aims to highlight the differences between different clear aligner therapies that differ in the presence of attachments or in attachment configuration. Eight electronic databases were searched up to March 2020. Two authors independently proceeded to study selection, data extraction, and risk of bias assessment. The analysis of the results was carried out examining six groups of movements (mesio-distal tipping/bodily movement; anterior bucco-lingual tipping/root torque; posterior bucco-lingual tipping/expansion; intrusion; extrusion; rotation). Five clinical trials were selected and all of them showed a medium risk of bias. Literature showed that attachments mostly increase the effectiveness of orthodontic treatment with clear aligners, improving anterior root torque, rotation, and mesio-distal (M-D) movement; they are also important to increase posterior anchorage. However, some articles showed contradictory or not statistically significant results. Attachments also seem to improve intrusion, but the evidence about this movement, as well as extrusion, is lacking. No studies evaluated posterior bucco-lingual tipping/expansion. Further clinical trials are strongly suggested to clarify the influence of attachments and their number, size, shape, and position on each orthodontic movement.

Automated summary

This systematic review compares different clear aligner therapies with regards to the presence or configuration of attachments. The analysis of several clinical trials suggests that attachments can enhance the effectiveness of clear aligner treatment, particularly in improving root torque, rotation, and mesio-distal movement. However, the evidence is limited for intrusion and extrusion, and there is a lack of studies on posterior bucco-lingual tipping/expansion.