Implant-supported versus implant-retained distal extension mandibular partial overdentures and residual ridge resorption: a 5-year retrospective radiographic study in men
Elsyad, M.Abdou.; Habib, A.Ali.
International Journal of Prosthodontics 24(4): 306-313
2011
ISSN/ISBN: 0893-2174 PMID: 21716967 Document Number: 650699
This retrospective study sought to examine posterior mandibular ridge resorption under implant-supported and implant-retained distal extension partial overdentures in men at the end of a 5-year observation period. Class I mandibular partial edentulism was managed in 34 patients with removable partial overdentures that were adjunctively supported (n = 18) or retained (n = 16) via resilient attachments placed bilaterally on single implants (n = 68) in the first molar areas. Posterior Area Indices (PAI) were calculated for each patient by digitizing the traced rotational tomograms taken immediately before and after 5 years of treatment. Proportional rather than actual measurements were used in an effort to minimize errors related to magnification and distortion. Residual ridge resorption associated with the implant-supported partial overdentures was recorded as PAI =0.012 ± 0.022; it was PAI = 0.073 ± 0.044 for the implant-retained group. Estimated average reductions in ridge heights were 0.15 and 1.03 mm for implant-supported and implant-retained partial overdentures, respectively. Multiple linear regression models demonstrated that prosthesis type, initial mandibular ridge height, and relining frequency were significantly correlated with PAI. Implant-supported partial overdentures appear to be associated with reduced posterior mandibular alveolar ridge resorption when compared to implant-retained ones. Int J Prosthodont 2011;24:306-313.