Miethke and Vogt2005[257] Prospective controlled clinical trial 30 consecutive patients each with FA and with CA Periodontal health of patients during treatment with the Invisalign system and with FA • CA and FA
• Three consecutive control visits Evaluation of the periodontal health in patients during treatment with either FA or the Invisalign system A Miethke and Brauner2007[258] Prospective cohort study 30 patients each with aligners or fixed lingual appliances Periodontal health of patients during treatment with the Invisalign system and with fixed lingual appliances CA and FA Evaluation of the periodontal health of patients during treatment with the Invisalign system or fixed lingual appliances A Eliades et al., 2009[259] Experimental in vitro study Three sets, each consisting of a maxillary and a mandibular appliance, of as-received aligners Cytotoxicity and estrogenicity of Invisalign appliances Samples of eluents were diluted to 3 concentrations (5%, 10%, and 20% vol/vol) Study the in vitro cytotoxic and estrogenic properties of Invisalign appliances A Sombuntham et al., 2009[260] Animal study 15 rats were divided into 3 groups Early tooth movement with a clear plastic appliance in rats • Group I was the untreated controls; group II received a clear plastic appliance made from a model, with the maxillary left first molar repositioned mesially 0.5 mm from the origin; and group III had a closed-coil spring to move the molar mesially, changes in paradental tissues were evaluated on days 1, 4, and 7 Investigate early histologic changes of paradental tissues in response to a clear plastic appliance in rats A Low et al., 2011[261] Prospective clinical trial 56 Chinese male/female volunteers (aged 19–39 years) Ultrastructure and morphology of biofilms on thermoplastic orthodontic appliances in “fast” and “slow” plaque formers • Slow and fast plaque formers
• Tiles were collected at intervals of 1, 3, 6, 12, 24, and 48 h, as well as 3, 7, and 14 days Investigate the morphological features and distribution of biofilms on Invisalign orthodontic appliances, in a sample of “slow” and “fast” plaque formers using SEM A Shalish et al., 2012[189] Prospective cohort study 68 adult patients (45 females and 23 males) who comprised 3 groups: 28 Buccal, 19 Lingual, and 21 Invisalign patients Adult patients’ adjustability to orthodontic appliances: Labial, Lingual, and Invisalign™ • Labial, Lingual, and Invisalign™
• First week and again on day 14 Assess patients’ perception of pain and analgesic consumption Assess 4 areas of dysfunction: oral dysfunction, eating disturbances, general activity parameters, and oral symptoms A and B
(Aadjustability to CA) Krieger et al., 2013[262] Retrospective radiometric cohort study 100 patients (17–75 years of age) with a class I occlusion and anterior crowding before treatment, treated exclusively with Invisalign Apical root resorption during orthodontic treatment with aligners • Pre- and post-treatment panoramic radiographs
• Different teeth, gender, age or sagittal and vertical orthodontic tooth movement Investigate the incidence and severity of apical root resorptions during orthodontic treatment with aligners A Fujiyama et al., 2014[263] Prospective cohort study 145 cases for the edgewise group (EG; n=55), Invisalign group (IG; n=38), and edgewise and Invisalign group (EIG; n=52) Analysis of pain level in cases treated with Invisalign aligner in comparison with FA • CAT and FA
• VAS scores were collected during the first three stages (first stage: 0–7 days, second stage: 14–21 days, and third stage: 28–35 days) and at the end of the treatment (overall VAS score Evaluate and compare the difference in the level of pain using the VAS between cases treated with the edgewise appliance and Invisalign Identify the cause of pain and discomfort in the Invisalign cases A Premaraj et al., 2014[264] Experimental in vitro study Plastic was powdered with a 12-in half-circle, flat-bottom file, producing particles that were about 86×56 µm to 186×161 µm in size (length×width) Oral epithelial cell reaction after exposure to Invisalign plastic material Soaking Invisalign plastic in either saline solution or artificial saliva for 2, 4, and 8 weeks Evaluate the cellular responses of oral epithelium exposed to Invisalign plastic in vitro A Han 2015[265] Retrospective cohort study 35 patients who underwent orthodontic treatment Combined periodontal and orthodontic treatment with FA and CA in patients with periodontitis • CA and FA
• Clinical parameters were assessed at baseline and after orthodontic treatment and the duration of treatment was compared between these two groups Evaluate the effect of orthodontic treatment on periodontal tissue Compare orthodontic treatment with FA to CAT in periodontitis patients A Azaripour et al., 2015[266] Cross sectional study 100 patients (FO=50, Invisalign®=50) Gingival parameters and patient satisfaction with CAT CAT and FA Evaluate gingival and PDL parameters during orthodontic treatment of patients with FOA or Invisalign® Evaluate patient’s satisfaction during orthodontic treatment of patients with FOA or Invisalign® A Abbate et al., 2015[267] Randomized prospective clinical trial 50 teenagers aged 10–18 years with similar initial orthodontic conditions Periodontal health in teenagers treated with removable aligners and FA • CAT and FA patients
• Comparisons done at beginning of treatment and 3, 6, and 12 months later To explore the microbiological and periodontal changes occurring in adolescents during 12 months of orthodontic therapy with CA and FA Assess compliance with oral hygiene procedures, full mouth plaque score, and full mouth bleeding score at the beginning of treatment and 12 months later A Levrini et al. 2015[268] Prospective controlled clinical trial 77 patients Periodontal health status in patients treated with the Invisalign(®) system and FA • Invisalign(®) group, FA group and control group
• T0 (beginning of the treatment), T1 (1-month) and T2 (3-months) Compare the periodontal health and the microbiological changes via real-time polymerase chain reaction in patients treated with FA and Invisalign(®) system A Hellak et al., 2016[269] Retrospective cohort study 60 digital CBCT scans from 30 patients (28 women, two men; 30 CBCTs pre-treatment, 30 posttreatment) Influence of Invisalign treatment with IER on bone volume for adult crowding • 30 CBCTs pre-treatment, 30 post-treatment
• Mandible and maxilla Use 3D datasets to identify associations between treatment for adult crowding using Invisalign and IER and changes in the bone volume A Levrini et al., 2016[270] Prospective clinical study 20 subjects (6 males and 14 females) undergoing orthodontic therapy with CA ATP Bioluminometers analysis on the surfaces of CA after the use of different cleaning methods Different cleaning methods (water, brushing with toothpaste, and brushing with toothpaste and use of sodium carbonate and sulphate tablet) Quantify the bacteria concentration on the surface of Invisalign using three different cleaning methods Validate the efficacy of the bioluminometer in assessing the bacteria concentration A Allareddy et al., 2017[[271] Retrospective cohort study 173 medical device reports Adverse clinical events reported during Invisalign treatment Examine adverse clinical events after the use of the Invisalign system Provide an overview of the actions taken by the manufacturer to address these events A Gay et al., 2017[272] Prospective cohort radiometric study 71 class I adult healthy patients (mean age 32.8±12.7) treated with aligners Root resorption during orthodontic treatment with Invisalign Root and crown lengths of 1083 teeth were measured in panoramic radiographs at the beginning (T0) and at the end (T1) of CAT Investigate the incidence and severity of RR in adult patients treated with aligners A Castroflorio et al., 2017[273] Prospective split mouth clinical trial 10 healthy, adult patients Biochemical markers of bone metabolism during early orthodontic tooth movement with Invisalign aligners • 1 w and 3 w
• Tested teeth and control teeth Evaluate the expression of receptor activator of nuclear factor-kappa ligand, osteoprotegerin, osteopontin, interleukin 1β, and transforming growth factor ß1 in the gingival crevicular fluid of teeth subjected to orthodontic forces released by aligners A Iglesias-Linares et al., 2017[274] A case–control genetic association study 372 Caucasian patients treated with CA (Invisalign) or FA OIEARR in patients treated with FA versus CA CA and FA Determine whether orthodontic treatment with CA versus FA is associated with a different frequency of OIEARR when genetic, radiographic, and clinical factors are accounted for A Hellak et al., 2018[275] Retrospective cohort 3D CBCT study 60 CBCT scans from 30 adult patients (28 women, 2 men; 30 CBCTs pre-treatment, 30 post-treatment) Influence on interradicular bone volume of Invisalign treatment for adult crowding with IER • Four levels in the anterior tooth areas of the maxilla and mandible
• Differences in bone between T0 and T1 Use 3D datasets to identify associations between treatment for adult crowding, using Invisalign aligner and IER Assess changes in the volume of interradicular bone A Almasoud 2018[276] Prospective cohort study 64 patients Pain perception among patients treated with passive self-ligating FA and Invisalign®aligners during the 1st week of orthodontic treatment • Self-ligating FA and Invisalign®aligners
• Their responses were recorded at 4 h, 24 h, day 3, and day 7 Compare the perception of pain between patients treated with passive self-ligating FA and those treated with Invisalign aligners A Aman et al., 2018[277] Retrospective cohort study using CBCT 160 patients who received comprehensive orthodontic treatment with CA Apical root resorption during orthodontic treatment with Invisalign clear aligners using CBCT • Pre-treatment and post-treatment CBCT examinations
• Maxillary central and lateral incisors Investigate the incidence and severity of orthodontically induced inflammatory root resorption on maxillary incisors with CA therapy using CBCT Identify possible risk factors for orthodontically induced inflammatory root resorption A Yi et al., 2018[278] Retrospective cohort study 80 non-extraction patients EARR in non-extraction cases after CAT or FA CAT and FA Comparatively evaluate the amount of EARR in non-extraction patients receiving CAT or FA Investigate the potential predictive factors of EARR: duration of treatment, gender, age, skeletal pattern or degree of malocclusion A Katchooi et al., 2018[279] Randomized prospective clinical trial 26 adult subjects Effect of supplemental vibration on orthodontic treatment with aligners Either an active (A) or a sham (B) AcceleDent Aura device (OrthoAccel Technologies, Inc) • Investigate the effects of AcceleDent on Invisalign treatment
• The outcomes were the ability to complete the initial set of aligners and the incisor irregularity measurements for those who completed their regimen of aligners Assess aligner compliance, pain levels, and oral health-related quality of life data A Guo et al., 2018[280] 3m prospective cohort study 10 female patients with CA Profiling of subgingival plaque biofilm microbiota in female adult patients with CA 3 time points: before orthodontic treatment (T0), 1 month after orthodontic treatment (T1) and 3 months after orthodontic treatment (T2) Investigate changes of the subgingival microbial community Examine subgingival microbial community association with clinical characteristics during the first 3 months of CAT A Patini et al., 2018[281] Retrospective cohort study A CA (TG) of 68 patients and a control group of 33 untreated patients (UG) Invisalign Clear aligners’ effects on aesthetics: evaluation of facial wrinkles • Treated with CA and untreated
• Comparison based on age: subgroup 1 if under 40 years of age and subgroup 2 if over 40 years
• Facial aesthetics of the lower third was evaluated at the beginning (T0) and at the end (T1) of the study period Evaluate the facial esthetic effects of orthodontic treatment performed with CA and to compare it to an untreated control group, on lower third facial aging in adult patients through the use of the Wrinkle Severity Rating Scale at the beginning (T0) and at the end (T1) of the study period A Parrini et al., 2018[282] Prospective cohort study 15 untreated patients and 15 patients treated with CA Postural changes in orthodontic patients treated with CA • Treated patients with CAT and untreated patients
• Patients treated with CA were compared at baseline, after 1, 3 and 6 months Evaluate possible correlations between orthodontic treatment and posture:
the kyphotic angle, the lordotic angle, the upper thoracic inclination, and the pelvic inclination A Farouk et al., 2018[283] Retrospective study 30 patients with an average age of 26±11 years and Class I malocclusion Effect of the application of HFV on tooth length concurrent with CAT • Group I received adjunctive HFV
• Group II, the control, did not receive adjunctive mechanical treatment
• Before (T1) and after (T2) treatment Evaluate the possible change in teeth lengths as an indicator of OITRR after HFV treatment concurrent with Invisalign Smart Track®aligners as evaluated by CBCT A Pogal-Sussman-Gandia et al., 2019[284] Prospective cohort study 30 patients undergoing active two-arch Invisalign®treatment were examined Effects of Invisalign®treatment on speech articulation Patients’ speech was recorded once with the trays inserted and once with the trays removed Determine the effects of Invisalign®aligners on patients’ perception on speech articulation and abilities to articulate consonants Assess quality
and rate of speech A Oliverio et al., 2019[285] Randomized prospective clinical trial 38 volunteers who were undergoing orthodontic treatment with F22 aligner Tooth whitening in association with CAT • Group 1 (8 patients): Application of 3% hydrogen peroxide for 9 h/day on days 7–14 of aligner wear
• Group 2 (8 patients): Application of 10% carbamide peroxide for 9 h/day on days 7–14 of aligner wear
• Group 3 (8 patients): Application of 16% carbamide peroxide for 9 h/day on days 7–14 of aligner wear
• Group 4 (14 patients): Application of 16% carbamide peroxide for 9 h/day on days 1–14 of aligner wear Evaluate the efficacy of different at-home whitening protocols during orthodontic CAT • Qualitative analysis of whitening agent distribution within the F22 aligners
• Assess difference in transparency of aligners
• Compare the light transmittance and absorbance of the aligners before and after whitening A Wang et al., 2019[286] Prospective cohort study 15 subjects aged 20–25 years, non-smokers, without any diagnosed systemic diseases, and having received no antibiotics in the 3 months before sampling Alterations of the oral microbiome in patients treated with the Invisalign system or with FA Comparison between CAT group, FA group and no treatment group Influence of different treatments on oral microbotome regarding the diversity of oral microbial composition and the richness and evenness of samples • Investigate oral microbotome at phyla and genus levels between different treatments regarding predominancy and abundancy
• Investigate differences in microbial function A Abu Alhaija et al., 2019[287] Randomized prospective clinical trial 45 subjects: 25 in FA group and 20 in CA group Comparative study of initial changes in PBF between CA and FA • CA and FA
• Maxillary right and mandibular left teeth
• Different time intervals (20 min, 48 h, 72 h, and 1 month) after the fitting of the nickel titanium archwire in group 1 and after the delivery of the second aligner in group 2 Evaluate and compare the initial changes of PBF using clear aligner and fixed orthodontic treatment A Lombardo et al., 2020[288] Prospective cohort longitudinal study 2 groups of patients to be treated, respectively, with CAs (14 patients; 9 females and 5 males; mean age 21 years±0.25) and FAs (13 patients; 8 females and 5 males; mean 14 years±0.75) Short-term variation in the subgingival microbiota in 2 groups of patients treated with CA and FA • CA and FA
• The right upper central incisor and right first molar at four different time points: before appliance fitting (T0), and at 1 month (T1), 3 months (T3) and 6 months (T6) thereafter Evaluate the subgingival microbiological changes during the first 6 months of therapy with CAs and FAs A Antonio-Zancajo et al., 2020[289] Prospective clinical trial 120 patients (54 men, 66 women) divided into 4 groups of 30 patients each Pain and oral-health-related quality of life in orthodontic patients during initial therapy with CON, low-Friction, and lingual Brackets and aligners (Invisalign) Different types of orthodontic appliances: CON and CON low-friction brackets, lingual brackets, and aligners Compare pain and its relationship with the oral quality of life of patients with different types of orthodontic appliances: CON and CON low-friction brackets, lingual brackets, and aligners A Tran et al., 2020[290] Multi-site prospective cohort study 27 adults about to start CAT Impact of CAT on tooth pain and masticatory muscle soreness Comparison between baseline, dummy aligner, Invisalign first active aligner and second active aligner Investigate tooth pain and masticatory muscle soreness and tenderness in patients undergoing CAT Explore whether psychological traits affected these primary outcomes A Albhaisi et al., 2020[291] Prospective randomized clinical trial 49 patients (39 female, 10 males; mean age±standard deviation, 21.25±3 years)
(42 completed the study) Enamel demineralization during CAT compared with FA Comparison between CAT and FA groups before treatment (T0) and 3 months later (T1) Investigate the relationship between CAT and the development of white spot lesions and compare it with FA therapy by means of mean amount of fluorescence loss (ΔF) Assess number of newly developed lesions, deepest point in the lesion (ΔFMax), lesion area (pixels), and plaque surface area (ΔR30) A Mulla Issa et al., 2020[292] A cross-sectional study 80 patients coming for regular appointments undergoing orthodontic treatment Periodontal parameters in adult patients with CAT versus three other types of brackets CAT versus the three other types of brackets, that is, CON metal, CON ceramic, and metal self-ligating Assess the gingival parameters in the CAT versus the 3 other types of brackets, that is, CON metal, CON ceramic, and metal self-ligating A Zhao et al., 2020[293] 6-month prospective clinical study 25 adult patients receiving Invisalign aligner Dynamics of the oral microbiome and oral health among patients receiving CAT Comparison between before the treatment (Group B) and at a 6-months follow-up (Group P) Assess the impacts of Invisalign appliances on the oral bacterial community and biodiversity Record clinical periodontal parameters and daily oral hygiene habits A Li et al., 2020[294] Retrospective cohort study A total of 373 roots from 70 subjects, with similar baseline characteristics and ABO discrepancy index scores Prevalence and severity of apical root resorption during orthodontic treatment with CA and FA by CBCT CAT and FA Investigate and compare the prevalence and severity of ARR in patients treated with CA and FA using CBCT Investigate which types of teeth had the greatest severity of RR A Levrini et al., 2020[295] FEA in vitro study and prospective clinical study 10 patients were selected for the clinical study Dental bleaching during orthodontic treatment with aligners • 3 sample areas of gel application on the maxillary central incisors (the incisal edge, the middle part, and the gingival edge) were analyzed
• Teeth 41 and 32 (control teeth, with reservoirs) were compared with that on teeth 31 and 42 (study teeth, without reservoirs) Determine the tooth whitening effectiveness of trays with no reservoirs (Invisalign aligners or Vivera retainers used as bleaching trays), initially with a FEA and subsequently with a clinical study using spectrophotometry A Al Nazeh et al., 2020[296] Prospective longitudinal cohort study 50 patients (26 females and 24 males; mean age=27.62±8.25 years, SE=1.17, 95% CI=24.71–29.89 years) Relationship between oral health impacts and personality profiles among orthodontic patients treated with CA Before and after treatment with Invisalign orthodontic treatment Assess oral health impacts before and after Invisalign orthodontic treatment and their relationships with personality characteristics A Meazzini et al., 2020[297] Prospective cohort study 100 syndromic Caucasian patients affected by various CFA from 2 different hospitals Comparison of pain perception in patients affected by cleft and CFA treated with FA or Invisalign CA and FA Compare the difference in pain perception CAT and FA in patients affected by cleft and CFA A Barreda et al., 2020[298] Prospective clinical trial 19 patients with orthodontic expansion requirement treated with Invisalign®aligners Clinical and tomographic evaluation of PDL health status and maxillary buccal bone changes in expansion treatment using CA • Measurements were done before starting treatment (T0) and at 12 months (T1)
• Bone thickness was measured at two levels: 4 mm (CEJ+4) and 6 mm (CEJ+6) apical to the CEJ Evaluate changes in periodontal status and maxillary buccal bone by considering clinical and tomographic parameters during the first year of orthodontic expansion with Invisalign®aligners A Kaur and El-Bialy 2020[299] Retrospective clinical study 34 patients (9 males, 25 females; average age 41.37±15.02) who finished their orthodontic treatment using an intraoral LIPUS device and Invisalign CA in a private clinic Shortening of overall orthodontic treatment duration with LIPUS • 34 patients who finished their orthodontic treatment using an intraoral LIPUS device and Invisalign clear aligners
• A control group (34) matching for the same malocclusions was randomly selected from finished treatment cases of the same clinician Determine if there is a reduction in the overall treatment duration in orthodontic patients using low-LIPUS and Invisalign SmartTrack®clear aligners Assess compliance of the patients using LIPUS with CA in comparison to control group A Xie et al., 2020[300] Experimental in vitro study and animal study 6 mm disc from the aligners to represent the aligners Gold Nanoclusters-Coated orthodontic devices can inhibit the formation of Streptococcus mutans Biofilm • Highest concentration of QA-GNCs in well 1 and gradient diluted QA-GNCs in well 2–11
• The well 12 was the negative control group without any drug Test modifying orthodontic devices (e.g., Invisalign aligner) with QA-GNCs as an antibiotic reagent to prevent bacterial contamination and biofilm formation Test the effect of incubation time (2, 4, 6, 8, 10, 12, 24 h) on the coatings A Zhang et al., 2020[301] Both in vitro and in vivo animal assays Biological Safe Gold Nanoparticle-Modified dental aligner prevents the Porphyromonas gingivalis biofilm formation Compared with the traditional oral administration method Investigate the anti-P. gingivalis properties of surface-modified Invisalign with a stable antimicrobial coating system, optical antibacterial density measurement, contact assay, and SEM were performed • Investigate the effect of AuDAPT on biofilm formation
• Evaluate the biocompatibility of AuDAPT- based coating, including its influence on human periodontal ligament fibroblast cell (hPDLC) viability and irritation of the rat oral mucosa A Xie et al., 2020[302] Experimental in vitro study The whole Invisalign aligners (the maximum length, width, and height are about 6, 5, and 1 cm, respectively) Near-Infrared Light-Activated phototherapy by Gold Nanoclusters for dispersing biofilms DNase-AuNCs TG with untreated control groups
Ordinary medical gargle (compound chlorhexidine gargle) and alcohol (75%) in biofilm dispersing • Design and synthesize and assess DNase-decorated AuNCs (DNase-AuNCs), which are capable of dispersing bacterial biofilms and killing the encapsulated bacteria
• Examine phototherapy of bacterial biofilms on an Invisalign Aligner • Assess effect of irradiation time and Laser intensity on the phototherapy effects of DNase-AuNCs
• Biosafety test of DNase-AuNCs A Nemec et al., 2020[303] Experimental in vitro study One set of aligners (Invisalign, Align Technology, San Jose, CA, USA) containing 69 upper and lower aligners was ordered Behaviour of human oral epithelial cells grown on Invisalign®SmartTrack®Material Examine the cell functional and morphological parameters of human oral squamous carcinoma cells directly grown on aligners made of SmartTrack material • Investigate cell morphology, proliferation/viability, cell death, and gene expression of several functional proteins
• Investigate inflammatory cytokines, such as interleukin (IL)-8, and IL-6 and intercellular adhesion molecule 1 A Gao et al., 2020[304] Prospective cohort study Total of 110 patients
(55 pairs) Comparison of pain perception, anxiety, and impacts on oral health-related quality of life between patients receiving CA and FA during the initial stage of orthodontic treatment • CA and FA
• Different days: first to day 14 Compare pain perception, anxiety, and impacts on oral health-related quality of life between adult patients receiving CA and FA during the initial stage of orthodontic treatments A Wang et al., 2020[305] Randomized prospective controlled clinical trial 28 subjects were enrolled in the investigational arm and 15 in the control group Effects of root resorption after orthodontic treatment using pulsating force Effect of the device on root resorption during orthodontic treatment was compared with a control group of patients who received Invisalign treatment Study the effect of the device on root resorption during orthodontic treatment using CBCT and compared with a control group of patients who received Invisalign treatment A Lou et al., 2021[306] Prospective cohort study 17 healthy adults without TMD (16 females, 1 male; mean age±standard deviation, 35.3±17.6 years) Evaluation of masticatory muscle response to CAT using ambulatory electromyographic recording Comparisons over 4 weeks
week 1 without aligners (baseline), week 2 with a passive aligner (dummy), week 3 with their first active aligner (active1), and week 4 with their second active aligner (active2) Measure the activity of the masseter during CAT using ambulatory electromyography Explore whether psychological traits modulate the masticatory muscle response to CAT A Campos Zeffa et al., 2021[307] Prospective cohort longitudinal Study 12 Angle Class I and II orthodontic patients undergoing treatment with FA and 15 patients treated with CA Influence of CON or Invisalign treatment on mineral and trace element salivary levels with Total Reflection X-ray Fluorescence • CAT and FA
• Before treatment (pre) and after 3 months of treatment (post) Evaluate the salivary concentration of chemical elements in patients undergoing orthodontic treatment with FA and removable aligners Evaluate secretion rate of chemical elements A Liu et al., 2021[308] Retrospective study 320 incisors from 40 Class II patients treated with aligners (Invisalign) Volumetric CBCT evaluation and risk factor analysis of EARR with CAT Pretreatment (T0) and posttreatment (T1) Investigate the prevalence and severity of EARR volumetrically with CAT using CBCT Determine the possible risk factors and develop a prediction model for EARR A Al-Dboush et al., 2021[309] Retrospective study 84 subjects who were treated using CAT Impact of photobiomodulation and LIPUS adjunctive interventions on orthodontic treatment duration during CAT 28 patients were treated using CAT with a daily use of LIPUS for 20 min, 28 patients were treated using CAT with a daily use of PBM for 10 min, and 28 patients were treated using CAT alone Assess the efficiency of LIPUS and PBM interventions in accelerating orthodontic tooth movement during CAT A Antonio-Zancajo et al., 2021[310] Prospective clinical trial 120 patients divided into four groups Comparative analysis of periodontal pain according to the type of precision orthodontic appliances: vestibular, lingual and aligners Four groups: Conventional (CON), Low Friction (LF), Lingual (LO) and Aligners (INV) Analyze the pain (intensity, location and type) that patients presented after the placement of different types of orthodontic appliances: CON, LF, lingual and aligners A Seleem et al., 2021[311] Prospective clinical controlled trial 28 patients at Western University dental center Effect of 10% carbamide peroxide on tooth shade, plaque index and gingival index during invisalign treatment Two groups where the experimental Group applied daily bleaching material (10% CP, Ultradent Inc., South Jordan, UT, USA), while the control group did not for 4 weeks at baseline and in 2-week intervals for 6 weeks Investigate whether 10% CP use during Invisalign treatment can enhance tooth shade esthetics while decreasing plaque levels and improving gingival health indices A Miller et al., 2003[190] Retrospective validation study Two identical digital models of one subject’s orthodontic treatment Validation of Align Technology’s Treat III digital model superimposition tool and its case application Compare two identical digital models using 12 selected points from the palatal rugae Assessment of the efficacy and accuracy of three-dimensional computer-based predictive orthodontic systems requires that new methods of treatment analysis be developed and validated B
(Translation and rotation) Djeu et al., 2005[191] Retrospective cohort study 48 patients (Invisalign and braces groups) Outcome assessment of Invisalign and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system Comparison between Invisalign group and FA group Objectively compare treatment outcome of Invisalign compared with braces Assess duration, strengths and weaknesses of Invisalign compared with braces B
(ABO-OGS) Duong and Kuo 2006[192] Prospective clinical trial n=20 Finishing with Invisalign. EX40 Aligner was compared to thinner aligner E×30 and compared to ClinCheck goal Explore procedure for finishing and the optimal material for finishing Obtain data regarding the types of tooth positions that require overcorrection and the amount of overcorrection required to achieve the results shown at the final stage on Clincheck B Miller et al., 2007[193] Prospective, longitudinal cohort study 60 adult orthodontic patients (33 with Invisalign aligners, 27 with FA) A comparison of treatment impacts between Invisalign aligner and FA therapy during the 1st week of treatment • CAT and FA
• A baseline survey was completed before the start of treatment; diary entries were made for 7 consecutive days to measure various impacts of the subjects’ orthodontic treatment over time Evaluate the differences in quality of life impacts between subjects treated with Invisalign aligners and those with FA during the 1stweek of orthodontic treatment B
(Quality of life impacts) Kuncio et al., 2007[194] Prospective cohort study Final sample size for both groups was 11 Invisalign and traditional orthodontic treatment postretention outcomes compared using the American Board of Orthodontics objective grading system • CA and FA
• Cases were evaluated immediately after appliance removal (T1) and at a postretention time (T2), and 3 years after appliance removal Compare the postretention dental changes between patients treated with Invisalign and those treated with FA B
(Postretention dental changes) Kravitz et al., 2009[195] Pprospective clinical study 37 Patients treated with anterior Invisalign Efficacy of tooth movement with Invisalign Comparison between predicted and achieved tooth movement Evaluate the efficacy of tooth movement with Invisalign B
(Expansion, constriction, intrusion, extrusion, mesiodistal tip, labiolingual tip, and rotation) Schaefer and Braumann 2010[196] Prospective cohort study 31 patients with good periodontal health Halitosis, oral health and quality of life during treatment with Invisalign(®) and the effect of a low-dose chlorhexidine solution • Group 1: CHX/no CHX,
• Group 2: no CHX/CHX) Examine how halitosis, oral dryness and general oral health were impacted during treatment with the Invisalign(®) system Evaluate the effect of a low dose chlorhexidine solution (CHX) B
(Quality of life) Krieger et al., 2011[197] Retrospective study 35 patients aged between 15 and 59 were measured Accuracy of Invisalign®treatments in the anterior tooth region Pre-and post-treatment models as well as the initial and final position of the ClinCheck Analyse to what extent the pretreatment model at the beginning of the treatment corresponds to the initial position in the ClinCheck® Analyze to what extent the predicted treatment result corresponds to the actual result of the therapy at the end of the treatment B
(Overjet, Overbite, dental midline shift) Pavoni et al., 2011[198] Prospective clinical study 20 subjects Analysis of dento-alveolar effects in using Self-ligating versus Invisalign LF self-ligating brackets TIME 3 compared to the Invisalign technique Evaluate the changes in the transverse dimension and the perimeter of the maxillary arch produced by LF self-ligating brackets TIME 3 compared to the Invisalign technique Assess difference between the treatment durations of both modalities B
(Changes in the transverse dimension and the perimeter of the maxillary arch) Krieger et al., 2012[199] Retrospective study 50 patients (15–63 years of age) Achievement of predicted tooth movement in anterior region by Invisalign Pre-and post-treatment casts as well as initial and final ClinChecks®models Compare casts to their corresponding digital ClinCheck®models at baseline Compare the tooth movement achieved at the end of aligner therapy (Invisalign®) to the predicted movement in the anterior region B
(upper/lower anterior arch length and intercanine distance, overjet, overbite, dental midline shift, and the irregularity index according to Little Irregularity Index) Simon et al., 2014[200] Split mouth retrospective design 30 consecutive patients who required orthodontic treatment with Invisalign® Treatment outcome and efficacy of an aligner technique-regarding incisor torque, premolar derotation and molar distalization • Different movements were compared (1) Incisor Torque>10°, (2) Premolar derotation >10° (3) Molar distalization>1.5 mm.
• The groups (1–3) were subdivided: in the first subgroup (a) the movements were supported with the use of an attachment, while in the subgroup (b) no auxiliaries were used (except incisor torque, in which Power Ridges were used)
• Achieved OTM compared with predicted Investigate the efficacy of orthodontic treatment using the Invisalign®system Analyze the influence of auxiliaries (Attachment/Power Ridge) as well as the staging (movement per aligner) on treatment efficacy B and C
(Incisor torque, premolar derotation and molar distalization) Ercoli et al., 2014[201] Prospective clinical study 20 patients in age from 16 to 45 years (mean 31.7±8.7 years) Comparison of two different clear aligner systems Compare two different clear aligner systems: “Nuvola®” system with “Fantasmino®” system Compare the “Nuvola®” system with “Fantasmino®” system (patient’s satisfaction, improvement of the irregularity index, speech impairment, and mean wear time) Examine their material properties, and define the indications for use of the aligners B and E
(patient’s satisfaction, improvement of the irregularity index, speech impairment, and mean wear time) Li et al., 2015[202] A multicenter
randomized prospective controlled trial 152 adult orthodontic patients The effectiveness of the Invisalign appliance in extraction cases using the the ABO model grading system CAT and FA patients Assess treatment outcomes of the Invisalign and compare results with braces using ABO model grading system in extraction cases B
(Extraction cases) Grünheid et al., 2016[203] Retrospective study 30 patients treated with CA and 30 patients treated with FA Effect of CAT on the buccolingual inclination of mandibular canines and the intercanine distance • CAT and FA
• Pre- and post-treatment measurements Compare the changes in buccolinugal inclination of mandibular canines and intercanine distance in patients treated with CA to those treated with preadjusted edgewise appliances B
(Buccolingual inclination of mandibular canines and the intercanine distance) Duncan et al., 2016[204] Retrospective chart review 61 adult white patients Changes in mandibular incisor position and arch form resulting from Invisalign correction of the crowded dentition treated nonextraction • 20 mild (2.0–3.9 mm), 22 moderate (4.0–5.9 mm), and 19 severe (>6.0 mm)
• T0 and T1 values Investigate changes in mandibular incisor position resulting from Invisalign correction of the crowded dentition without extraction B
(Mandibular incisor position without extraction) Best et al., 2016[205] Cross sectional study Orthodontists (n=1000) and general dentists (n=1000) who were providers of aligner treatment Treatment management between orthodontists and general practitioners performing CAT Orthodontists and general practitioners Investigate differences in case selection, treatment management, and aligner treatment expertise between orthodontists and general practitioners B
(Expertise) Hennessy et al., 2016[206] Randomized prospective clinical trial 44 patients (mean age, 26.4±7.7 years) Comparing mandibular incisor proclination produced by fixed labial appliances and CA CA and FA
Comparing pretreatment and near-end treatment lateral cephalograms Compare the mandibular incisor proclination produced by FA and third generation CA B
(Mandibular incisor proclination) Ravera et al., 2016[207] Multicenter retrospective study 40 lateral cephalograms obtained from 20 non-growing subjects (9 male, 11 female; average age 29.73 years) Maxillary molar distalization with aligners in adult patients (T0) pretreatment and (T2) post-treatment Test the hypothesis that bodily maxillary molar distalization was not achievable in aligner orthodontics B
(Maxillary molar distalization) Weir 2016[208] Prospective clinical study 12 patients, consecutively treated by the removal of a single lower incisor and Invisalign appliances Invisalign treatment of lower incisor ex