{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T11:24:39Z","timestamp":1764761079777,"version":"3.46.0"},"reference-count":44,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T00:00:00Z","timestamp":1764720000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Prosthesis"],"abstract":"<jats:p>Background\/Objectives: Stability, retention, and support are removable partial denture (RPD) biomechanical principles. The literature shows contradictory opinions on indirect retention in RPDs, but no solid scientific evidence exists. This in vitro research aims to analyze indirect retainers\u2019 (IRs) influence on forces transmitted to abutment teeth of a Kennedy Class I mandibular RPD. Methods: Bilateral distal-extension mandibular RPDs\u2014differing only in the presence or absence of an IR on tooth 44 (IR model vs. nonIR model, respectively)\u2014were installed on an acrylic master model. Tensile forces were applied perpendicularly to the occlusal plane on the longest free-end saddle\u2019s distal aspect. Electronic speckle pattern interferometry (ESPI) measurements were obtained with and without an IR. The three-dimensional out-of-plane displacements of both models were acquired. Results: Abutment teeth 46 and 47 contralateral to the longest distal extension suffered more deformation under displacement forces when an IR was used. In turn, the IR\u2019s influence on the deformation values of the abutment tooth 34 adjacent to the larger edentulous area depended on the intensity of the tensile force exerted: low-intensity forces resulted in reduced deformation, while higher-intensity forces resulted in higher deformation. Conclusions: This study\u2019s findings indicate that indirect retention promotes better tensile force distribution in the existent teeth. However, they also question the IR\u2019s role in protecting abutment teeth against excessive torque forces. This study\u2019s preliminary results highlight the need for research on indirect retention principles using new methodologies, namely, in silico and ex vivo studies, and their experimental and clinical validation.<\/jats:p>","DOI":"10.3390\/prosthesis7060157","type":"journal-article","created":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T10:34:01Z","timestamp":1764758041000},"page":"157","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Forces Transmitted to Abutment Teeth in Distal Extension Removable Partial Denture\u2014Impact of Indirect Retention"],"prefix":"10.3390","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6834-8703","authenticated-orcid":false,"given":"Susana Jo\u00e3o","family":"Oliveira","sequence":"first","affiliation":[{"name":"Faculty of Dental Medicine, University of Porto, 4200-393 Porto, Portugal"}]},{"given":"Margarida","family":"Sampaio-Fernandes","sequence":"additional","affiliation":[{"name":"Faculty of Dental Medicine, University of Porto, 4200-393 Porto, Portugal"},{"name":"Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), 4200-465 Porto, Portugal"}]},{"given":"Jos\u00e9 Carlos","family":"Reis-Campos","sequence":"additional","affiliation":[{"name":"Faculty of Dental Medicine, University of Porto, 4200-393 Porto, Portugal"},{"name":"Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0783-2355","authenticated-orcid":false,"given":"Manuel","family":"Sampaio-Fernandes","sequence":"additional","affiliation":[{"name":"Faculty of Dental Medicine, University of Porto, 4200-393 Porto, Portugal"},{"name":"Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6347-9608","authenticated-orcid":false,"given":"M\u00e1rio Augusto Pires","family":"Vaz","sequence":"additional","affiliation":[{"name":"Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), 4200-465 Porto, Portugal"},{"name":"Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal"},{"name":"Biomechanics Laboratory (LABIOMEP), 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8583-8096","authenticated-orcid":false,"given":"Maria Helena","family":"Figueiral","sequence":"additional","affiliation":[{"name":"Faculty of Dental Medicine, University of Porto, 4200-393 Porto, Portugal"},{"name":"Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,3]]},"reference":[{"key":"ref_1","unstructured":"Fuller, E., Steele, J., Watt, R., and Nuttall, N. (2011). Oral Health and Function\u2014A Report from the Adult Dental Health Survey 2009, The Health and Social Care Information Centre."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1067\/mpr.2002.121204","article-title":"Future needs for fixed and removable partial dentures in the United States","volume":"87","author":"Douglass","year":"2002","journal-title":"J. Prosthet. Dent."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e085479","DOI":"10.1136\/bmjopen-2024-085479","article-title":"Impact of edentulism on community-dwelling adults in low-income, middle-income and high-income countries: A systematic review","volume":"14","author":"Hunter","year":"2024","journal-title":"BMJ Open"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1111\/j.1600-0528.2001.290502.x","article-title":"Risk indicators of edentulism, partial tooth loss and prosthetic status among black and white middle-aged and older adults","volume":"29","author":"Dolan","year":"2001","journal-title":"Community Dent. Oral Epidemiol."},{"key":"ref_5","first-page":"139","article-title":"Indications for removable partial dentures: A literature review","volume":"18","author":"Jepson","year":"2005","journal-title":"Int. J. Prosthodont."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1111\/j.1532-849X.2010.00622.x","article-title":"Turning points in removable partial denture philosophy","volume":"19","author":"Waliszewski","year":"2010","journal-title":"J. Prosthodont."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1177\/2050168420943435","article-title":"Removable Partial Dentures for Older Adults","volume":"9","author":"Friel","year":"2020","journal-title":"Prim. Dent. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1111\/j.1365-2842.2011.02245.x","article-title":"Effect of treatment with fixed and removable dental prostheses: An oral health-related quality of life study","volume":"39","author":"Ozhayat","year":"2012","journal-title":"J. Oral Rehabil."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1111\/jopr.12526","article-title":"Factors Influencing Removable Partial Denture Patient-Reported Outcomes of Quality of Life and Satisfaction: A Systematic Review","volume":"26","author":"Cooper","year":"2017","journal-title":"J. Prosthodont."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"365","DOI":"10.3109\/00016359709059201","article-title":"Does the quality of advanced prosthetic dentistry determine patient satisfaction?","volume":"55","author":"Hakestam","year":"1997","journal-title":"Acta Odontol. Scand."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/S0022-3913(00)70008-4","article-title":"Relationship between the standards of removable partial denture construction, clinical acceptability, and patient satisfaction","volume":"83","author":"Frank","year":"2000","journal-title":"J. Prosthet. Dent."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"(1995). Principles, concepts, and practices in prosthodontics\u20141994. J. Prosthet. Dent., 73, 73\u201394. Academy of Prosthodontics.","DOI":"10.1016\/S0022-3913(05)80276-8"},{"key":"ref_13","unstructured":"Carr, A.B., and Brown, D.T. (2011). McCracken\u2019s Removable Partial Prosthodontics, Elsevier Mosby. [12th ed.]."},{"key":"ref_14","unstructured":"Marxkors, R. (1984). The Partial Denture with Metal Framework, BEGO, Bremer Goldschl\u00e4garei Wilhelm Herbst."},{"key":"ref_15","first-page":"371","article-title":"Removable partial denture design: A need to focus on hygienic principles?","volume":"15","author":"Owall","year":"2002","journal-title":"Int. J. Prosthodont."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"539","DOI":"10.2186\/jpr.JPR_D_22_00135","article-title":"Effect of mandibular bilateral distal extension denture design on masticatory performance","volume":"67","author":"Yoshimoto","year":"2023","journal-title":"J. Prosthodont. Res."},{"key":"ref_17","unstructured":"Anthony, L.P. (1942). Partial denture service. The American Textbook of Prosthetic Dentistry, Lea & Feibiger."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0022-3913(03)00155-0","article-title":"Indirect retention in partial denture design. 1996","volume":"90","author":"Avant","year":"2003","journal-title":"J. Prosthet. Dent."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1038\/sj.bdj.4800902a","article-title":"Indirect retention","volume":"190","author":"Davenport","year":"2001","journal-title":"Br. Dent. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"506","DOI":"10.1016\/0022-3913(82)90352-3","article-title":"Caries, periodontal and prosthetic findings in patients with removable partial dentures: A ten-year longitudinal study","volume":"48","author":"Bergman","year":"1982","journal-title":"J. Prosthet. Dent."},{"key":"ref_21","first-page":"403","article-title":"Denture mobility during chewing; a study method","volume":"59","author":"Hedegard","year":"1966","journal-title":"Swed. Dent. J."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1111\/j.1365-2842.1985.tb01542.x","article-title":"Periodontal problems associated with use of distal extension removable partial dentures-a matter of construction?","volume":"12","author":"Berg","year":"1985","journal-title":"J. Oral Rehabil."},{"key":"ref_23","first-page":"34","article-title":"Mastering the removable partial denture\u2014Part one: Basic reflections about construction","volume":"14","author":"Marxkors","year":"1997","journal-title":"J. Dent. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1016\/j.radphyschem.2013.05.051","article-title":"DH and ESPI laser interferometry applied to the restoration shrinkage assessment","volume":"94","author":"Campos","year":"2014","journal-title":"Radiat. Phys. Chem."},{"key":"ref_25","first-page":"111","article-title":"Holographic stress analysis in a distal extension removable partial denture","volume":"17","author":"Campos","year":"2009","journal-title":"Eur. J. Prosthodont. Restor. Dent."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"636","DOI":"10.1016\/j.prosdent.2020.07.006","article-title":"Attachment-retained removable prostheses: Patient satisfaction and quality of life assessment","volume":"125","author":"Swelem","year":"2021","journal-title":"J. Prosthet. Dent."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1002\/cre2.521","article-title":"Implant-supported removable partial dentures compared to conventional dentures: A systematic review and meta-analysis of quality of life, patient satisfaction, and biomechanical complications","volume":"8","author":"Bandiaky","year":"2022","journal-title":"Clin. Exp. Dent. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1111\/j.1365-2842.2007.01755.x","article-title":"Dental endosseous implants in the medically compromised patient","volume":"34","author":"Scully","year":"2007","journal-title":"J. Oral Rehabil."},{"key":"ref_29","first-page":"261","article-title":"Appropriatech: Prosthodontics for the many, not just for the few","volume":"17","author":"Owen","year":"2004","journal-title":"Int. J. Prosthodont."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"116","DOI":"10.4103\/0972-4052.179318","article-title":"Some issues related to evidence-based implantology","volume":"16","author":"Carlsson","year":"2016","journal-title":"J. Indian Prosthodont. Soc."},{"key":"ref_31","first-page":"530","article-title":"Periodontal considerations in removable partial denture design","volume":"8","author":"Jacobson","year":"1987","journal-title":"Compendium"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1111\/j.1365-2842.1980.tb00431.x","article-title":"Host response to two different designs of minor connector","volume":"7","author":"Runov","year":"1980","journal-title":"J. Oral Rehabil."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1902\/jop.2002.73.2.137","article-title":"The effect of removable partial dentures on periodontal health of abutment and non-abutment teeth","volume":"73","author":"Zlataric","year":"2002","journal-title":"J. Periodontol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1111\/jopr.12449","article-title":"Periodontal Conditions of Abutments and Non-Abutments in Removable Partial Dentures over 7 Years of Use","volume":"26","year":"2017","journal-title":"J. Prosthodont."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1038\/sj.bdj.4801122a","article-title":"Caries incidence following restoration of shortened lower dental arches in a randomized controlled trial","volume":"191","author":"Jepson","year":"2001","journal-title":"Br. Dent. J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"105624","DOI":"10.1016\/j.jdent.2025.105624","article-title":"Development of a nomogram for root caries risk assessment in a Chinese elderly population","volume":"156","author":"Huang","year":"2025","journal-title":"J. Dent."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1016\/0022-3913(77)90024-5","article-title":"An investigation of the effectiveness of indirect retainers","volume":"38","author":"Frank","year":"1977","journal-title":"J. Prosthet. Dent."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1111\/j.1365-2842.2010.02069.x","article-title":"A clinical follow-up study of the periodontal conditions of RPD abutment and non-abutment teeth","volume":"37","author":"Barreto","year":"2010","journal-title":"J. Oral Rehabil."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1590\/S0103-64402006000400003","article-title":"Holographic interferometry method for assessment of static load stress distribution in dog mandible","volume":"17","author":"Campos","year":"2006","journal-title":"Braz. Dent. J."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1007\/s10237-011-0348-5","article-title":"Analysis of the compressive strain below the removable and fixed prosthesis in the posterior mandible using a digital image correlation method","volume":"11","author":"Tanasic","year":"2012","journal-title":"Biomech. Model. Mechanobiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/0022-3913(79)90295-6","article-title":"The measurement of forces transmitted to abutment teeth of removable partial dentures","volume":"41","author":"Maxfield","year":"1979","journal-title":"J. Prosthet. Dent."},{"key":"ref_42","first-page":"50","article-title":"Effects of a removable partial denture and its rest location on the forces exerted on an abutment tooth in vivo","volume":"21","author":"Kawata","year":"2008","journal-title":"Int. J. Prosthodont."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1016\/j.jobcr.2014.11.008","article-title":"Finite element analysis: A boon to dentistry","volume":"4","author":"Trivedi","year":"2014","journal-title":"J. Oral Biol. Craniofac. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"105348","DOI":"10.1016\/j.jdent.2024.105348","article-title":"Finite element models: A road to in-silico modeling in the age of personalized dentistry","volume":"150","author":"Lahoud","year":"2024","journal-title":"J. Dent."}],"container-title":["Prosthesis"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2673-1592\/7\/6\/157\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,3]],"date-time":"2025-12-03T11:16:13Z","timestamp":1764760573000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2673-1592\/7\/6\/157"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,3]]},"references-count":44,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["prosthesis7060157"],"URL":"https:\/\/doi.org\/10.3390\/prosthesis7060157","relation":{},"ISSN":["2673-1592"],"issn-type":[{"value":"2673-1592","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,3]]}}}