Discussion
We found that orthodontic treatment has less negative impact on Invisalign® patients than on FOA patients with respect to both gingival condition and patient well being. We did not find any significant plaque accumulation in both patient groups.
It has been shown that FOA can lead to increased plaque accumulation and reduced oral hygiene during orthodontic treatment.[12,13] Various studies compared different orthodontic approaches and it was shown that removable appliances caused less plaque accumulation and better oral health.[7,8,14]
Increased plaque accumulation[3,4,15] can lead to gingival inflammation, increased susceptibility to caries, decalcifications or white spot lesions.[15–17] Miethke et al. showed that the plaque index was significantly lower in patients treated with Invisalign® than in FOA patients, but that other periodontal conditions in both groups were similar.[7] Due the introductory training provided for oral hygiene and instructions for optimal tooth brushing, all patients in our study were very cooperative. The majority of patients used the regular recall appointments and put great emphasis on dental esthetics. This may be a reason why we did not find a significant difference in plaque accumulation between both patient groups.
In contrast, gingival inflammation was significantly lower in the Invisalign® patients whereas Miethke et al. reported significant differences only inside the groups. In a later study, Miethke et al. compared the gingival status in orthodontic patients treated with Invisalign® or lingual brackets and found that periodontal parameters were worse in patients with lingual brackets.[8]
Although the majority of study participants had a satisfactory oral hygiene, the difference in time needed for brushing teeth was clearly shorter in Invisalign® patients than in FOA patients. This difference is certainly due to removal of Invisalign® aligners which facilitates an easier and faster tooth cleaning.
Borutta et al. found that in patients with FOA, electric toothbrushes gave better oral hygiene results than manual brushing. A significantly better plaque removal and reduction of gingival inflammation was observed when tooth brushing was done manually.[16] In contrast, Hickman et al.[15] and Deery et al.[17] observed no significant differences between the two tooth brushing systems. In our study, the patients' toothbrush preferences were similar in both treatment groups.
Sergl et al.[18] described the impairment of everyday life as a result of orthodontic treatment. Bernabé et al. showed that there was significantly greater impact on the daily life of patients with FOA as compared to patients with removable appliances.[19] In their study, impairments in speech and eating habits were especially noted in patients who were in the 15–16 years age category.
It must be mentioned that in our study the average age of the FOA and Invisalign® patients was notably different; the FOA group mainly consisted of teenagers and young adults whereas the Invisalign® group consisted primarily of adults. Therefore, we used linear regression models for our confirmatory questions and adjust for age to exclude the effect of age on the outcome of our study.
BMC Oral Health. 2015;15(69) © 2015 BioMed Central, Ltd.
