title: Effect of simulated masticatory loading on the retention of stud attachments for implant overdentures.
abstract: This study assessed the effect of simulated mastication on the retention of two stud attachment systems for 2-implants overdentures. Sixteen specimens, each simulating an edentulous ridge with implants and an overdenture were divided into two groups, according to the attachment system: Group I (Nobel Biocare ball-socket attachments) and Group II (Locator attachments). Retention forces were measured before and after 400,000 simulated masticatory loads in a customised device. Data were compared by two-way anova followed by Bonferroni test (α = 0·05). Group I presented significantly lower retention forces (Newtons) than Group II at baseline (10·6 ± 3·6 and 66·4 ± 16·0, respectively). However, differences were not significant after 400,000 loads (7·9 ± 4·3 and 21·6 ± 17·0). The number of cycles did not influence the measurements in Group I, whereas a non-linear descending curve was found for Group II. It was concluded that simulated mastication resulted in minor changes for the ball attachment tested. Nevertheless, it reduced the retention of Locator attachments to 40% of the baseline values, what suggests that mastication is a major factor associated with maintenance needs for this system.
authors.affiliation: Faculty of Dentistry, McGill University, Montreal, QC, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Abi Nader
authors.forename: R F
authors.initials: RF
authors.lastname: de Souza
authors.forename: D
authors.initials: D
authors.lastname: Fortin
authors.forename: L
authors.initials: L
authors.lastname: De Koninck
authors.forename: O
authors.initials: O
authors.lastname: Fromentin
authors.forename: R F
authors.initials: RF
authors.lastname: Albuquerque Junior
mesh_terms: D001732:Bite Force; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019554:Dental Restoration Wear; D003799:Dental Stress Analysis / Q000295:instrumentation; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation*; D003828:Denture, Overlay; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009757:Nylons / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D003764:Dental Materials; D009757:Nylons; C041500:titanium nitride; D014025:Titanium