Hiltrud Dasy1, Andreas Dasy1, Greg Asatrian2, Noémi Rózsa3, Hao-Fu Lee4, Jin Hee Kwak5. 1. a Postgraduate Student, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Calif. 2. b Dental Student, School of Dentistry, University of California, Los Angeles, Calif. 3. c Associate Professor, Department for Paediatric Dentistry and Orthodontics, Faculty for Dentistry, Semmelweis University, Budapest, Hungary. 4. d Instructor, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Calif. 5. e Assistant Professor, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Calif.
Abstract
OBJECTIVE: To evaluate the retention of four types of aligners on a dental arch with various attachments. MATERIALS AND METHODS: For this study, three casts were manufactured, two of which contained attachments (ellipsoid and beveled), and one without any attachments to serve as a control. Four types of aligners were thermoformed: Clear-Aligner (CA)-soft, CA-medium, and CA-hard, with various thicknesses, and Essix ACE. Measurements of vertical displacement force during aligner removal were performed with the Gabo Qualimeter Eplexor. Means and standard deviations were next compared between different aligner thicknesses and attachment shapes. RESULTS: CA-soft, CA-medium, and CA-hard did not present a significant increase in retention, except when used in the presence of attachments. Additionally, CA-medium and CA-hard required significantly more force for removal. Essix ACE demonstrated a significant decrease in retention when used with ellipsoid attachments. The force value for Essix ACE removal from the cast with beveled attachments was comparable to that of CA-medium. Forces for aligner removal from the model without attachments showed a linear trend. Essix ACE did not show a continuous increase in retention for each model. Overall, ellipsoid attachments did not present a significant change in retention. In contrast, beveled attachments improved retention. CONCLUSIONS: Ellipsoid attachments had no significant influence on the force required for aligner removal and hence on aligner retention. Essix ACE showed significantly less retention than CA-hard on the models with attachments. Furthermore, beveled attachments were observed to increase retention significantly, compared with ellipsoid attachments and when using no attachments.
OBJECTIVE: To evaluate the retention of four types of aligners on a dental arch with various attachments. MATERIALS AND METHODS: For this study, three casts were manufactured, two of which contained attachments (ellipsoid and beveled), and one without any attachments to serve as a control. Four types of aligners were thermoformed: Clear-Aligner (CA)-soft, CA-medium, and CA-hard, with various thicknesses, and EssixACE. Measurements of vertical displacement force during aligner removal were performed with the Gabo Qualimeter Eplexor. Means and standard deviations were next compared between different aligner thicknesses and attachment shapes. RESULTS: CA-soft, CA-medium, and CA-hard did not present a significant increase in retention, except when used in the presence of attachments. Additionally, CA-medium and CA-hard required significantly more force for removal. EssixACE demonstrated a significant decrease in retention when used with ellipsoid attachments. The force value for EssixACE removal from the cast with beveled attachments was comparable to that of CA-medium. Forces for aligner removal from the model without attachments showed a linear trend. EssixACE did not show a continuous increase in retention for each model. Overall, ellipsoid attachments did not present a significant change in retention. In contrast, beveled attachments improved retention. CONCLUSIONS: Ellipsoid attachments had no significant influence on the force required for aligner removal and hence on aligner retention. EssixACE showed significantly less retention than CA-hard on the models with attachments. Furthermore, beveled attachments were observed to increase retention significantly, compared with ellipsoid attachments and when using no attachments.
Authors: Bashair A Alsaud; Maher S Hajjaj; Ahmad I Masoud; Ensanya A Abou Neel; Dalia A Abuelenain; Amal I Linjawi Journal: Materials (Basel) Date: 2022-06-10 Impact factor: 3.748
Authors: Giovanna Perrotti; Alessandro Carrafiello; Ornella Rossi; Lorena Karanxha; Giulia Baccaglione; Massimo Del Fabbro Journal: Int J Environ Res Public Health Date: 2022-05-09 Impact factor: 4.614