title: Photoelastic analysis of implant-retained and conventional obturator prostheses with different attachment systems and soft relining.
abstract: Complete and partial loss of maxillary bone may jeopardize oral physiology and generate complications as oral-sinus-nasal communication. Palatal obturator prostheses are a treatment alternative for rehabilitation of these patients. The aim of this study was to assess stress distribution, through photoelasticity, on palatal obturator prostheses associated with different attachment systems (o'ring, bar clip, and o'ring/bar clip) of implants and submitted to relining. Two photoelastic models were fabricated according to an experimental maxillary model with oral-sinus-nasal communication. One model did not present implants, whereas the other included 2 implants with 13.0 mm in length in the left ridge. Four colorless maxillary obturator prostheses were fabricated and relined with soft silicone. One of these prostheses presented no attachment system, whereas the remaining prostheses included attachment systems adapted to the implants. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope during loading with 100 N at 10 mm/s. The results were based on observation during the experiment and photographic records of stress on the photoelastic model. The bar clip system exhibited the highest stress concentration followed by o'ring/bar clip and o'ring systems. The attachment systems presented different stress distribution with greater concentration surrounding the implants and homogenous stress distribution on the photoelastic model without implants. The highest concentration of fringes occurred, in ascending order, with o'ring, o'ring/bar clip, and bar clip systems.
authors.affiliation: From the Department of Dentistry Materials and Prosthesis, Faculty of Dentistry of Araçatuba, University of the State of São Paulo, Brazil.
authors.forename: Paula
authors.initials: P
authors.lastname: do Prado Ribeiro
authors.forename: Marcelo Coelho
authors.initials: MC
authors.lastname: Goiato
authors.forename: Eduardo Pizza
authors.initials: EP
authors.lastname: Pellizzer
authors.forename: Aldiéris Alves
authors.initials: AA
authors.lastname: Pesqueira
authors.forename: Marcela Filiè
authors.initials: MF
authors.lastname: Haddad
authors.forename: Stefan Fiuza
authors.initials: SF
authors.lastname: de Carvalho Dekon
authors.forename: Daniela Micheline
authors.initials: DM
authors.lastname: dos Santos
mesh_terms: D001696:Biomechanical Phenomena; D017268:Dental Prosthesis Retention / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003822:Denture Liners; D006801:Humans; D008027:Light; D008422:Materials Testing; D008437:Maxilla / Q000601:surgery*; D010158:Palatal Obturators; D010781:Photography; D011474:Prosthesis Design; D013499:Surface Properties; D014025:Titanium
chemical_list: D014025:Titanium