Clear aligners for orthodontic treatment?

Cigarette smoke and tobacco heating aerosol on the aging of clear aligners

BACKGROUND

The treatments with clear aligners (CA) showed an exponential higher percentage in the last years being almost invisible with major patient acceptability and a resulting improvement in quality of life. CA are composed of thermoplastic polyurethane not inert but subjected to changes due to heating and humidity, chewing forces, and prolonged exposure to enzymes in saliva in the oral cavity and external factors. Cigarette smoke (CS) and the aerosol produced by tobacco products with reduced health risks may be considered among the external factors affecting CA. The purpose of this study was the assessment of optical properties (absorbance and transmittance) and roughness of CA after in vitro aging due to exposition to CS and THS2.2, compared to controls. The secondary objective will be the investigation of CS and THS2.2 effects on resin composite inside aligners used for attachments during treatment with CA.

METHODS

A total number of 60 CA units will be used and equally divided in three different groups (20 in each): CS group exposed to reference cigarettes smoking, THS2.2 group exposed to aerosol from 20 heat-not-burn sticks, and control group, CG to pure air only. The aligners will present ten introflection for the attachments on the anterior part. In accordance with ISO standard 3402, 3R4F cigarettes and THS2.2 tobacco sticks must undergo conditioning for a minimum of 48 hours and a maximum of 21 days at a temperature of 22±1 °C and a relative humidity of 60±3%.

RESULTS

Using spectrophotometry, the optical characteristics (absorbance and transmittance) of each aligner will be evaluated after aging (Jasco UV-vis V630PC, Tokyo, Japan). Each aligner will be cut with a rotating saw from canine to canine prior to the measurements in order to lop off the lingual region and displaying the labial barrier. The absorbance and transmittance measurements will be collected and statistically analyzed with a significance of P<0.05.

CONCLUSIONS

Surface roughness of the aligners and attachments inside them will be assessed by 3D scanning microscopy (Infinite Focus G4h). Color of resin composite will be assessed using the (CIE Lab) Commission Internationale de l'Eclairage L*a*b* color space by means of Olympus CrystalEyef dental spectrophotometer. Clinicians should advise patients to refrain from smoking and drinking coffee or tea while wearing aligners for two reasons: first, the color change is unacceptably noticeable when wearing aligners, and second, the material's chemical composition may be slightly altered, which could affect the intended dental movements.

Clear aligner treatment: different perspectives between orthodontists and general dentists

Purpose

To evaluate differences between orthodontists and general dentists in experience with clear aligners (CA), patients’ demand and perception, types of patients, and malocclusion treated with CA and to compare the two groups of clinicians not using CA in their practice.

Methods

A Web-based survey was developed and sent to the 129 members of the European Aligner Society and randomly to 200 doctors of dental surgery by e-mail. They responded on demographics and to one of two different parts for clinicians using CA or not using CA. Statistical analysis was performed with SAS EGv.6.1.

Results

The response rate was 74%. Among the total of respondents, the majority reported utilizing CA in their practice with a greater percentage of orthodontists (P = 0.0040). Overall, orthodontists learned more about CA during academic seminars comparing to general dentists, and they treated more class I with crowding (P = 0.0002) and with open bite (P = 0.0462). The majority of patients treated with CA were female and adults with a full-time employment, and the patients’ knowledge about CA treatment was mainly provided by information from external media advertising. For respondents not using CA, orthodontists were more likely to report that CA limit treatment outcomes, whereas general practitioners were reported not having enough experience to use them.

Conclusions

There were some significant differences between orthodontists and general dentists mainly in experience and case selection for clinicians using CA as well as in the reasons provided for not using CA in their practice.

Electronic supplementary material

The online version of this article (10.1186/s40510-019-0263-3) contains supplementary material, which is available to authorized users.