Dental Asia Jan/Feb 2019

Clinical Feature DENTAL ASIA JANUARY / FEBRUARY 2019 38 brushing, flossing and eating which promotes better oral hygiene. Aligners are clear, aesthetically pleasing and comfortable – with no metal brackets or wires that may cause irritation. Teeth can also be whitened with the appliance during treatment. Other recorded advantages include shortened appointment times, decreased allergic responses, decreased occlusal abrasion from parafunctional habits during treatment, facilitation of aligner retention, disarticulation of teeth which may be advantageous for patients with TMJ problems, it being technically much easier to use as compared to lingual appliances and the ability to present the final results to the patient prior to treatment. However, there is a lack of operator control and the inability to integrate hard and soft tissues of the head into the computer treatment and clinicians have no direct indication of where teeth are in relation to the basal bone or in relation to lips or other soft tissues of the head. 6 Boyd reported that aligner users who are teens showed improved periodontal status compared to patients with fixed appliances. 7 Patients are able to remove the aligners when they eat drink or brush. Several studies indicate that the periodontal status improved after active orthodontic treatment with aligners due to the correction of crowding. Additionally, stripping can also improve the periodontal status by restoring adequate space to the gingival papilla. 2 The Nuvola System The Nuvola clear aligner from Italy was launched in 2010 as an alternative to traditional orthodontic appliances. Already a well-established brand in Germany, Romania, Bulgaria and UKmarkets, Nuvola is continuing to expand its reach, having penetrated the Asian market recently. Nuvola is a transparent aligner system designed to achieve gradual straightening of the teeth and correct overcrowding. The aligners allow mesial, distal, intrusion, extrusion and tipping-torque movements in order to achieve aesthetic and unobtrusive results. The aligners also enable interdental spaces to be closed or space to be created for implants. Nuvola aligners are made from a unique material specifically designed to optimise the correct alignment of teeth. Strong, flexible, stain resistant and transparent, Nuvola aligners follow the morphology of the teeth and allow for consistent application of gentle forces that move teeth progressively. They must be worn at least 20 hours daily for two weeks before being replaced by the next aligner to allow for progressive change. There are 12 progressive aligners per stage that provide strong and precise control at all times. Ercoli in 2014 evaluated the efficiency of the Nuvola system in controlling torque movement of the upper and lower anterior. He found that the system was able to produce clinical outcomes comparable to the planning of the digital setup for moderate crowding cases (up to 6 mm). 2 In 2018, Tepedino investigated 39 adult patients wearing only 12 Nuvola aligners and found the clinical outcomes were comparable to the digital setup planning of anterior torque movements. Levelling, aligning, intrusion and bodily distalisation of upper molars (<1.5 mm) were predictable, while rotations, extrusion and torquemovements were not. It was concluded that the Nuvola system determines good tooth movement and its size is agreeable to patients. The aligner’s properties and thickness, production process, the model’s precision and the positions of the aligner’s margin all contribute to the final performance. 10 According to the manufacturer, Nuvola provides the following special features: • NuvolaWEB offers full online management • A scanned STL impression file via NuvolaWEB • Fewer visits to the dentist required • Minimal attachments required • Competitively priced to increase patient pool • Prompt and reliable service from their lab • One-to-one clinical and technical support Aligner materials The aligners can be made out of PETG (Polyethylene Terephthalate Glycol), EVA (Ethylene vinyl acetate) or PC (Polycarbonite) materials. The polyethylene clear thermoplastic material is formed using a vacuum process which has enough stiffness to provide the desired tooth movements that help patients maintain good oral hygiene. The aligner’s material properties and thickness, the production process, the model’s precision, and the position of the aligner’s margin related to crowns all contribute to its final performance. 4 Fantasmono studied different aligner systems including Nuvola, Fantasmino and My Clear Brace. According to him, different brands are composed of new material types. PVC can reduce the optimal daily wear time of the appliances from 20 to 14 hours a day due to its plastic deformation characteristics when moderate orthodontic forces are applied. PETG aligners are unsuitable for bodily movements of upper central incisors in labial or palatal directions. 8 Alexandros also tested the materials and discovered significant differences in their The Nuvola System