Newsletter

1917 Biomechanics of a Clear Aligner with Soft Inner Layer

T.K. KALILI, A.A. CAPUTO, and M. WU, UCLA, Los Angeles, CA, USA

Objective: Use of clear aligners is sometimes accompanied by patient discomfort and difficulty during insertion and removal. Inclusion of a soft layer in the aligner, which contacts the teeth, may alleviate some of these effects. The purpose of this study was to evaluate stresses generated with an aligner laminated with a soft inner liner compared to an aligner without the soft liner. Methods: A photoelastic model of a dentulous adult maxilla was fabricated using different teeth and bone simulants. Polyvinyl siloxane impressions were made and poured up in stone. The central incisors were modified to represent desired orthodontic movement. Two types of clear aligners were fabricated off of the modified model. One aligner was fabricated from a polycarbonate sheet. Another aligner was fabricated from a polycarbonate sheet laminated with a lower modulus polyurethane. The laminated and un-laminated aligners were inserted on the model and resulting stresses observed in the field of the polari scope and photographed. Stress data for the two aligners was analyzed using a computer graphics program to quantify stress intensity by fringe number counting. Results: Similar stress distributions developed at the crestal bone between the central incisors with both aligners. However, the level of stress was significantly lower with the laminated aligner. Further, stress propagated apically along the root surfaces of these teeth with both aligners. Again, the stress levels were lower with the laminated aligner. To a lesser degree, stress was transferred along the roots of the lateral incisors; lower intensity seen with the laminated aligner. Conclusion: Both aligners tested produced similar stress distributions in the supporting bone simulant. The stresses associated with the laminated aligner were of lower intensity. Consequently, the aligner with a soft inner layer may alleviate the problems of patient discomfort and difficulty during insertion and removal of un-laminated aligners.

Seq #209 - Orthodontics and Tooth Movement
2:00 PM-3:15 PM, Friday, 23 March 2007 Ernest N. Morial Convention Center Exhibit Hall I2-J
Back to the Craniofacial Biology Program
Back to the IADR/AADR/CADR 85th General Session and Exhibition (March 21-24, 2007)

link to article

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Duration of Force with Laminated and Unlaminated Orthodontic Aligners

Stress Generated by Laminated Aligners For Class-III Mandibular Distraction

Stresses Generated from Orthodontic Options USING Micro-Implant

Accuracy Verification Of Aligner Cad Process

Effects of Orthodontic Aligner Laminate Thickness on Stress Production

Stress Generated by Laminated Aligners for Class III Mandibular Distraction

Stress Generated From Orthodontic Options Using Micro-Implant

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