Objective

To compare the duration of orthodontic treatment and Gingival Index (GI) scores in Class I malocclusion patients treated with a conventional straight-wire method (CG) or the Damon technique (DT).

Design

Two-arm, parallel, randomised clinical trial

Setting

A postgraduate orthodontic clinic

Participants

Patients with a balanced facial profile, a full permanent dentition and Angle's Class I malocclusion with moderate crowding.

Methods

The primary outcome was the duration of orthodontic treatment in months. GI scores throughout treatment were secondary outcomes and the PAR index was also assessed. Randomisation was accomplished using a table of random numbers and the allocation was concealed in sequentially numbered and opened, opaque, sealed envelopes. Blinding was applicable for PAR assessment only. Comparison of data between groups was performed with appropriate tests for independent samples.

Results

Twenty-two patients were randomly allocated to treatment in a 1:1 ratio to either CG or DT group. Age at the start of treatment, initial PAR index and GI scores were similar between groups. All patients completed the study, but the total duration of orthodontic treatment was almost half of the initial assumption. No statistically significant differences were observed in treatment duration (CG: Mean ( x ̄ ) = 14.5 months, Standard Deviation (SD) = ±3.03; DT: x ̄ = 12.25 months, SD = ±2.93; 95% Confidence Interval: −0.40 to 4.90; P = 0.093; t-test). The two groups did not differ statistically regarding the GI scores during the observational period. No serious harms were observed other than gingival inflammation associated with oral biofilm accumulation.

Conclusions

The present study did not reveal statistically significant differences between the compared, conventional straight-wire method and Damon technique-treated, Angle's Class I malocclusion groups regarding total treatment duration and GI scores.