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Aim:
The aim of the present study was to compare the accuracy of the actual space obtained through interproximal enamel reduction (IPR) compared to the amount of IPR planned through the digital setup during clear aligner treatment (CAT).
Materials and methods:
A total of 10 clinicians were randomly recruited using the Doctor Locator by Align Tec...
Citations
... This may be related to clinical research findings indicating that the actual amount of enamel removed during IPR procedures in vivo frequently does not correspond with the initially planned IPR amount. Typically, these clinical outcomes tend to result in a lower degree of enamel removal than originally intended values [30]. ...
Abstract: Background/Objectives: Machine learning (ML) models predicting the risk of refinement
(i.e., a subsequent course of treatment being necessary) in clear aligner therapy (CAT) were developed
and evaluated. Methods: An anonymized sample of 9942 CAT patients (70.6% females, 29.4% males,
age range 18–64 years, median 30.5 years), as provided by DrSmile, a large European CAT provider
based in Berlin, Germany, was used. Three different ML methods were employed: (1) logistic
regression with L1 regularization, (2) extreme gradient boosting (XGBoost), and (3) support vector
classification with a radial basis function kernel. In total, 74 factors were selected as predictors for
these methods and are consistent with clinical reasoning. Results: On a held-out test set with a
true-positive rate of 0.58, the logistic regression model has an area under the ROC curve (AUC) of
0.67, an average precision (AP) of 0.73, and Brier loss of 0.22; the XGBoost model has an AUC of 0.67,
an AP of 0.74, and Brier loss of 0.22; and the support vector model has a recall of 0.61 and a precision
of 0.64. The logistic regression and XGBoost models identify predictors influencing refinement
risk, including patient compliance, interproximal enamel reduction (IPR) and certain planned tooth
movements, for example, lingual translation of maxillary incisors being associated with the lowest risk
of refinement and rotation of mandibular incisors with the highest risk. Conclusions: These findings
suggest moderate, well-calibrated predictive accuracy with both regularized logistic regression and
XGBoost and underscore the influence the identified factors have on the risk of refinement in CAT,
emphasizing their importance in the careful planning of orthodontic treatment and the potential
for shorter treatment times, less patient discomfort, and fewer clinic visits. Identification of at-risk
individuals could support tailored clinical decision-making and enable targeted interventions.
... Вступ. Інтерпроксимальна редукція (реапроксимація) емалі представляє собою малоінвазивну маніпуляцію, що передбачає стоншення емалі на контактних поверхнях зубів, таким чином зменшуючи мезіодистальний розмір одиниці зубного ряду, і забезпечуючи умови для оптимізації корекції її положення при лікуванні скупченості зубів легкого та середнього ступенів важкості [2,7,11]. За даними систематичного огляду реалізація інтерпроксимальної редукції (ІПР) емалі повинна керуватися трьома основними принципами: 1) обов'язково забезпечувати наявність залишкового тонкого шару емалі в ділянці втручання; 2) проводити маніпуляцію в проекції поверхні з більшою вихідною товщиною емалі; 3) забезпечувати селективну редукцію на контактних поверхнях двох суміжних зубів [15]. ...
... De Felice M. та колеги описали схожі результати, демонструючи тенденцію до недосягнення показників запланованої редукції в ході реалізації маніпуляції, при чому середня різниця між такими складала 0,55 мм на верхній щелепі та 0,82 мм на нижній щелепі [2]. Автори також квантифікували точність процедури інтерпроксимальної редукції по відношенню до запланованого результату, яка складала 44,95% для верхньої щелепи та 37,20% для нижньої щелепи [2]. ...
... De Felice M. та колеги описали схожі результати, демонструючи тенденцію до недосягнення показників запланованої редукції в ході реалізації маніпуляції, при чому середня різниця між такими складала 0,55 мм на верхній щелепі та 0,82 мм на нижній щелепі [2]. Автори також квантифікували точність процедури інтерпроксимальної редукції по відношенню до запланованого результату, яка складала 44,95% для верхньої щелепи та 37,20% для нижньої щелепи [2]. Аналогічне за дизайном дослідження Hariharan A. та колег також констатувало тенденцію до недостатньої редукції емалі відносно запланованих показників з різницею в 0,13±0,17 мм між такими на верхній щелепі та 0,14±0,19 на нижній, хоча дані показники відрізнялися в проекції різних зубів [8]. ...
Вступ. Інтерпроксимальна редукція (реапроксимація) емалі представляє собою малоінвазивну маніпуляцію, що передбачає стоншення емалі на контактних поверхнях зубів, таким чином зменшуючи мезіодистальний розмір одиниці зубного ряду, і забезпечуючи умови для оптимізації корекції її положення при лікуванні скупченості зубів легкого та середнього ступенів важкості. Мета дослідження. Оцінити можливості використання функцій цифрового сканування зубних рядів та гіпсових моделей для оптимізації виконання процедури інтерпроксимальної редукції (ІПР) емалі та верифікації результатів даного втручання. Матеріали та методи. Аналіз літературних даних передбачав опрацювання наукових публікацій, в яких були відображені різні можливості та цілі застосування цифрового сканування зубних рядів та гіпсових моделей в ході виконання процедури інтерпроксимальної редукції. Пошук публікацій здійснювався виключно у базі PubMed Central (https://www.ncbi.nlm.nih.gov/pmc/) за наступними ключовими словами «interproximal enamel reduction» та «digital scan». Результати досліджень та їх обговорення. В жодному з проаналізованих досліджень щодо відповідності між запланованою та досягнутою редукцією емалі, яка оцінювалась за даними цифрового сканування зубів чи моделей, не проводилось порівняння точності різних технік та систем сканування, правдивість та прецизійність котрих може впливати на варіацію отриманих результатів. Крім того, важливо оцінити наскільки валідними є результати вихідного сканування та подальшого графічного рендерингу зображень контактних поверхонь зубів, зареєстрованих з використанням різних систем та технологій сканування. Доцільним також є верифікації змін конфігурації та міграції контактних пунктів та площин за даними інтраорального сканування після проведення процедури інтерпроксимальної редукції емалі, враховуючи потенційний вплив даних факторів на зміни стану тканин пародонту в області втручання. Перспективним виглядає розробка підходів до навігаційного контролю проведення маніпуляції інтерпроксимальної редукції емалі. Висновки. Можливості використання функцій цифрового сканування зубних рядів та гіпсових моделей для оптимізації виконання процедури інтерпроксимальної редукції емалі та верифікації результатів даного втручання, включають наступні: 1) оцінка клінічної ситуації та об’єктивізація обсягу майбутнього втручання на основі отриманих інтраоральних сканів; 2) планування етапу практичної реалізації процедури інтерпроксимальної редукції емалі, маркування зон безпечного втручання на основі варіацій товщини емалі на контактних поверхнях різних зубів, та виходячи з цього моделювання навігаційного шаблону для контрольованого виконання ІПР; 3) верифікації фактичного обсягу редукції емалі попередньо запланованому на основі аналізу результатів повторного інтраорального чи позаротового сканування.
... The actual amount of enamel removed during procedures conducted on the patient can deviate from the initially intended interproximal reduction (IPR) in virtual planning. Research shows that in most cases, the executed IPR is lower than what had been initially anticipated [53][54]. Hariharan et al. found that the amount of implemented IPR is consistently lower than the digitally programmed values, particularly noted in mandibular anterior teeth and maxillary posterior teeth [55]. ...
Interproximal reduction (IPR) has become a standard practice in orthodontic treatment, particularly in the clear aligner therapy. It became an integral part of the digital plan when using clear aligners. Given the irreversible nature of IPR, precise planning and performance is essential. This article aims to analyze and summarize the existing literature on IPR in the context of clear aligners. The goal is to help clinicians to gain essential knowledge for safely and effectively navigating IPR. The review critically examines different perspectives found in the literature, covering indications, methods, and outcomes. Topics exploring the impact of IPR on treatment outcomes include space gaining, addressing tooth size discrepancies, tooth shape adjustments, resolving malocclusion, and enhancing aesthetics. Emphasizing precision of the procedure by the clinician and awareness of contraindications, the article also discusses the impact of IPR on patients. This includes considerations like increased pulp temperature, susceptibility to cavities due to changes in enamel roughness, effects on soft tissues, and post-IPR tooth sensitivity.
... However, these tooth-colored brackets also failed to satisfy the aesthetic demands and led clinicians to use even less visible orthodontic materials such as clear aligners. [1][2][3][4] Movement of teeth without the use of bands, brackets, and wires was first introduced in 1945 by Dr. Kesling 5 , who performed orthodontic treatment using a flexible tooth positioning device. Then, in 1997, the Invisalign® system (Align Technology Inc, Santa Clara, CA, USA) took Kesling's 5 philosophy further and produced a range of transparent and removable devices using computer-aided design and manufacturing technology. ...
... 6,8,9 The advantages of these systems are improved esthetics, increased patient comfort and oral hygiene, and healthier periodontal tissues. 3,10,11 Success in clear aligner therapy (CAT) depends on various patient-related factors, such as bone density and crown and root morphology of the teeth, as well as operator-related factors, such as an appropriate treatment plan, close follow-up of the treatment process, and accurate execution of the preplanned IPR. Features such as the thickness and material of the clear aligners and the shape and position of the attachments also play an important role in the treatment success of clear aligners. ...
... Features such as the thickness and material of the clear aligners and the shape and position of the attachments also play an important role in the treatment success of clear aligners. 3 IPR, also known as stripping, enamel re-proximation, slenderizing, interdental enamel re-proximation, and selective enamel reduction, is a clinical procedure commonly used in orthodontic practice to eliminate black triangles by reshaping two neighboring teeth, to treat mild to moderate crowding, to eliminate Bolton tooth size discrepancy and to stabilize dental arches. [12][13][14][15][16][17] The most preferred IPR techniques in clinical practice are hand-or motor-operated abrasive metal strips, thin diamond burs and diamond-coated discs used with a handpiece. ...
Objective
To compare the consistency of two interproximal reduction (IPR) methods in terms of the amount of planned and performed IPR during clear aligner therapy (CAT).
Methods
Thirty-four patients who received IPR using hand-operated abrasive strips (Group 1, 20 patients, 162 teeth) and motor-driven 3/4 oscillating segmental disks (Group 2, 14 patients, 134 teeth) during CAT were included in this preliminary study. The consistency between the planned and performed IPR amounts was evaluated within and between groups for teeth and quadrants.
Results
In Group 1, the amount of IPR performed on teeth numbers 22 and 43 and in the upper left quadrant was found to be statistically less than that of planned. On the other hand, the amount of performed IPR was statistically higher on tooth number 44 and in the upper right quadrant, whereas it was statistically less on tooth number 33 when compared with the planned amount in Group 2. The inconsistency between the planned and performed IPR amounts were statistically significant only in Group 1 and for teeth numbers 11, 21, 32, 33, and 43. No significant difference was found when the same parameter was compared between the groups.
Conclusion
The consistency of IPR was found to be better with the motor-driven oscillating disk system than with the hand-operated IPR strip system.
... Interproximal reduction has become a popular clinical protocol particularly with the advent of increase usage of clear aligner therapy even though research shows that the intended IPR varies with the actual IPR. [16] A completely formed enamel consists of 96% of organic material and 4% water while the inorganic content is mainly composed of calcium and phosphate which is substituted by carbonate ions. The main elements in enamel are carbon, oxygen, calcium, and phosphorous [17]. ...
Objective
This study aimed to evaluate the chemical composition of the proximal enamel surface and the surface characteristics subjected to different extents of interproximal reduction (IPR) in a clinical setting.
Materials and methods
Premolars of orthodontic patients which were designated for extraction were subjected to .2 mm, .3 mm, and .5 mm of IPR. After 1 month, the teeth were extracted and the teeth were subjected to scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDX).
Results
The SEM images of the three experimental groups (taken at magnification of 500 × and 2000 ×) showed that the enamel surfaces were irregular and rough compared to the honey comb appearance of the unstripped group. Small areas of erosion of enamel surface were seen in Group I (0.2 mm) under 2000 × magnification compared to Group IV (control) which showed typical arrangement of enamel rods in alternating orientation. The enamel surfaces of stripped and unstripped enamel contained calcium, phosphorus, carbon, oxygen, and nitrogen. The differences were not statistically significant and neither were the calcium phosphorous stoichiometric ratios between the four groups.
Conclusions
On analyzing the surface characteristics of enamel using SEM between the stripped and unstripped surfaces, there were irregularities and roughness seen in stripped surface whereas honey comb pattern was observed in unstripped enamel surfaces. The elements found in unstripped and stripped enamel surfaces were calcium, phosphorous, carbon, oxygen, and nitrogen. Although the calcium and phosphorus were high in the 0.5 mm IPR group, the difference between stripped and unstripped enamel surfaces was statistically not significant.
Clinical relevance
There have been concerns that IPR can remove the superficial mineral-rich layer making the deeper layers more susceptible to carious attack. No study has evaluated the mineral content in different layers of enamel in response to IPR in vivo and this study found no significant difference between pristine enamel and enamel subjected to IPR. The results of this study strengthen the validity of the clinical protocol employed.
... 8 In addition, the interproximal reduction (IPR) of enamel is commonly used in conjunction with CAT to aid attainment of treatment objectives. 9,10 Recent studies, however, have indicated that there may be uncertainty surrounding the use of CR attachments and IPR in CAT. 4,6,[9][10][11] Just over 72% of respondents in a 2022 survey of orthodontists indicated that CR attachments were "almost" or "always" a factor in need of change in the initial treatment plan provided by a CAT provider. ...
... 9,10 Recent studies, however, have indicated that there may be uncertainty surrounding the use of CR attachments and IPR in CAT. 4,6,[9][10][11] Just over 72% of respondents in a 2022 survey of orthodontists indicated that CR attachments were "almost" or "always" a factor in need of change in the initial treatment plan provided by a CAT provider. 4 In addition, recent investigations indicated that the amount of IPR prescribed by the orthodontist as part of the treatment plan is frequently not achieved. ...
... 4 In addition, recent investigations indicated that the amount of IPR prescribed by the orthodontist as part of the treatment plan is frequently not achieved. [9][10][11] CAT requires close communication between the orthodontist and the provider of the aligners. 3 This is usually mediated through a digital interface. ...
Objectives
To survey treatment-planning practices of orthodontists related to the Invisalign Lite clear aligner appliance (Align Technology, San Jose, Calif).
Materials and Methods
Patients satisfying inclusion and exclusion criteria and treated with Invisalign Lite were selected from a database containing more than 17,000 patients. Relevant data regarding treatment-planning practices were obtained from Align Technology’s treatment-planning facility, ClinCheck, and evaluated.
Results
Most (n = 135; 79.9%) patients were female and had a median (interquartile range [IQR]) age of 30.5 (23.8, 43.1) years. The median (IQR) number of aligners for the sample was 23.0 (14, 28) for the maxilla and 24 (14, 28) for the mandible. Most (n = 122; 72.2%) patients required at least one additional series of aligners. More locations for interproximal reduction (IPR) were prescribed in the mandible (mean 1.91 [1.78]) than in the maxilla (1.03 [1.78]; P < .024) in the initial accepted plan of all patients. More teeth were prescribed composite resin (CR) attachments in the maxilla (P < .0001) in the initial accepted plan of all patients. Issues regarding tooth position protocols (n = 50; 53.3%) and requirement for additional IPR (n = 68; 45.3%) were reasons for treatment plan changes before acceptance of the initial treatment plan by orthodontists.
Conclusions
More than 7 of 10 patients required at least one additional series of aligners after the initial series of Invisalign Lite aligners was completed. Prescription of IPR was more common in the mandible, and prescription of CR attachments was more common in the maxilla.
... Flexible strips of fine material were used to remove small portions of enamel (IPR System, ContactEZ, Vancouver, WA, USA). This parameter was analysed dichotomously in the analysis [35,36]. ...
Objective
Aim of this randomized clinical controlled trial was to evaluate the influence of fixed orthodontic steel retainers on gingival health and recessions of mandibular anterior teeth.
Materials and methods
After end of the orthodontic treatment, patients were randomly assigned into the test (fixed steel retainer) or control group (modified removable vacuum-formed retainer). Periodontal parameters (periodontal probing depth: PPD; recession: REC; bleeding on probing: BOP) as well as plaque and gingival index were assessed on mandibular anterior teeth directly before attaching/handing over the retainer (baseline: BL), 6 and 12 months after orthodontic treatment.
Results
37 patients (test: n = 15, mean age: 16.1±4.2 years; control: n = 17, mean age: 17.1±5.4 years) completed the study. REC and PPD failed to show significant pairwise differences. The number of patients showing gingival health in the area of the mandibular anterior teeth (test: BL n = 10, 6 months n = 9, 12 months n = 11; control: BL n = 10, 6 months n = 16, 12 months n = 15) revealed a significant difference for the intra-group comparison between BL and 6 months in the control group (p = 0.043). The inter-group comparisons failed to show significant differences.
Conclusion
Young orthodontically treated patients with fixed steel retainers show in 73.3% healthy gingival conditions after one year which are comparable to the control group (88.2%). Gingival recessions were in a clinically non-relevant range at any time of the examination.
Clinical trial number
DRKS00016710.
... This has been described in a study by Kalemaj and Levrini, indicating that implemented IER seemed to be less than planned IER, especially for lower canines and distal surfaces of teeth [18]. De Felice and colleagues concluded that the amount of enamel removed in vivo did not correspond with the amount of IER planned [19]. In most cases, the performed IER amount was lower than planned. ...
Objectives
Interproximal enamel reduction (IER), commonly known as stripping, is a frequently used technique in orthodontic treatment to address issues related to arch length discrepancies and tooth size discrepancies (TSD). The use of digital set-up allows for precise prediction of the amount of IER required. TSD occurs when the sizes of maxillary and mandibular teeth are not in proportion to each other. This study aims to evaluate and compare the suggested IER values generated by the digital set-up of a customized lingual orthodontic appliance in both upper and lower arches, across sextants, and among different teeth concerning TSD.
Materials and methods
We analyzed suggested IER values from 809 cases. The statistical analysis was divided into two parts: part 1 focused on the number of stripped surfaces, and part 2 assessed the quantity of enamel removed. Comparisons were made between upper and lower arches, sextants, and teeth using the Friedman test, followed by pairwise Wilcoxon tests with Bonferroni correction.
Results
The study found that mandibular and frontal stripping were more frequently suggested than maxillary and posterior stripping. Lower canines were the teeth most commonly recommended for stripping, followed by upper incisors.
Conclusion
Within the scope and limits of this cohort study, we conclude that, in general, more IER is required in the mandible as compared to the maxilla. Particularly in the anterior sextants, IER might be necessary to achieve optimal alignment and occlusion.
... These authors did not analyze the reliability of the measurement technique and quantified the mesiodistal distances of each tooth, from second premolar to second premolar. However, posterior teeth have been recommended as the enamel thickness increases in these teeth despite presenting worse accessibility [37] The present study selected the True Definition intraoral since Guth et al. reported that True Definition showed higher trueness (21.8 µm) than Cerec Bluecam (34.2 µm), Cerec Omnicam (43.3 µm), Itero (49.0 µm), Lava C.O.S. (47.7 µm), TRIOS (25.7 µm), and TRIOS color (26.1 µm) digital impression systems for dental nature arch scanning [38]. Furthermore, the present study includes some limitations since Jivanescu et al. reported that the presence of adjacent teeth can decrease the view of interproximal surfaces [36]. ...
The aim of this study was to analyze and compare the accuracy of a novel interproximal enamel reduction (IPR) technique based on a computer-aided static navigation technique with respect to a conventional free-hand-based technique for interproximal enamel reduction. Twenty anatomical-based experimental cast models of polyurethane were randomly distributed into the following IPR techniques: IPR technique based on computer-aided static navigation technique (n = 10) (GI) for Group A and conventional free-hand-based technique for the IPR (n = 10) (FHT) for Group B. The anatomical-based experimental cast models of polyurethane randomly assigned to the GI study group were submitted for a preoperative 3D intraoral surface scan; then, datasets were uploaded into 3D implant-planning software to design virtual templates for the interproximal enamel reduction technique. Afterward, the anatomical-based experimental cast models of polyurethane of both GI and FHT study groups were subjected to a postoperative digital impression by a 3D intraoral surface scan to compare the accuracy of the interproximal enamel reduction techniques at the buccal (mm), lingual/palatal (mm), and angular (◦) levels using the Student t-test. Statistically significant differences between the interproximal enamel reduction technique based on the computer-aided static navigation technique and the conventional free-hand-based technique for the interproximal enamel reduction at the buccal (p = 0.0008) and lingual/palatal (p < 0.0001) levels; however, no statistically significant differences were shown at the angular level (p = 0.1042). The interproximal enamel reduction technique based on computer-aided static navigation technique was more accurate than the conventional free-hand-based technique for interproximal enamel reduction.
... Technological advances in the orthodontic practice led clear aligner treatment (CAT) meet the demand for a minimally visible and customized treatment modality; however, it is still one of the main topics of scientific research of how to maximize treatment efficiency [1,2]. Orthodontic treatment without the use of bands, brackets, and wires was first described in 1945 by Kesling [3] who used a flexible tooth positioning appliance to move the teeth. ...
... This new treatment approach offered the advantage of improved aesthetics, increased patient comfort, and better oral hygiene when compared to the conventional fixed mechanics [1,6,7]. In this system, digital scans are converted into virtual models via stereolithographic (STL) technology and processed with the ClinCheck™ software (Align Technology Inc, Santa Clara, CA, USA) to simulate virtual tooth movements and to plan where, when and how much interproximal reduction (IPR) is needed [4,8,9]. ...
... In this system, digital scans are converted into virtual models via stereolithographic (STL) technology and processed with the ClinCheck™ software (Align Technology Inc, Santa Clara, CA, USA) to simulate virtual tooth movements and to plan where, when and how much interproximal reduction (IPR) is needed [4,8,9]. During the process, IPR is planned according to the clinical case requirements such as the amount of crowding, Bolton excess, molar and canine relationships, and overjet to achieve well-aligned teeth with optimal interproximal contacts [1,4]. ...
Objectives
To comparatively assess 3 interproximal reduction (IPR) methods used in clear aligner treatment with regard to accuracy, and patient perception of discomfort and anxiety.
Materials and methods
A total of 42 patients, treated with the Invisalign® system, were included in this prospective trial and received one of the following IPR methods: hand-operated abrasive strips (group 1; 14 patients, 150 teeth), motor-driven 3/4 oscillating segmental discs (group 2; 14 patients, 134 teeth), or motor-driven abrasive strips (group 3; 14 patients, 133 teeth). Accuracy was evaluated using the difference between planned and executed IPR. Anxiety and discomfort levels experienced by the patients were evaluated using a questionnaire of 17 questions.
Results
The accuracy of IPR was high in groups 2 and 3; however, it was low in group 1 with the executed IPR significantly less than the planned amount. On quadrant-level, executed IPR was significantly less in the upper left quadrant in group 1, and significantly more in the upper right quadrant in group 2. The difference between planned IPR and executed IPR was significant for teeth 11, 21, 32, 33, and 43 in group 1, indicating deficiency. The average difference between planned IPR and executed IPR was 0.08 mm for group 1, 0.09 mm for group 2, and 0.1 mm for group 3. Anxiety and discomfort levels did not differ between the methods, but a negative correlation was observed between age and discomfort and anxiety levels.
Conclusions
The overall accuracy of the 2 motor-driven IPR methods was found to be better than the hand-operated system. Maxillary central incisors and mandibular canines were more prone to IPR deficiency when hand-operated abrasive strips were utilized. Patients were similarly comfortable with all 3 methods, and discomfort and anxiety levels decreased with age.
Clinical relevance
Motor-driven methods have proven to be more effective when compared to the hand-operated ones by means of precision, speed, and patient comfort. If the clinician favors a hand-operated method, it may be advised to perform slightly more IPR especially on mandibular canines and maxillary central incisors.
