Evaluation of the clinical behavior of 2 different materials for implant-supported interim fixed partial prostheses: A randomized clinical trial

J Prosthet Dent. 2020 Sep;124(3):351-356. doi: 10.1016/j.prosdent.2019.09.021. Epub 2019 Dec 4.

Abstract

Statement of problem: Clinical studies about interim implant-supported prostheses made of polymethylmethacrylate (PMMA) and polyoxymethylene (POM) have been limited to clinical reports or studies on the survival of implants subjected to immediate loading without evaluating the influence of the material used.

Purpose: The purpose of this randomized clinical trial was to evaluate the clinical performance of posterior resin interim implant-supported fixed partial dentures (FPDs) made of 2 different computer-aided design and computer-aided manufactured (CAD-CAM) materials: PMMA and POM.

Material and methods: A total of 21 participants received 49 interim implant-supported FPDs. The same participant received the PMMA as part of the control group and the POM as part of the experimental group. The restorations were evaluated at 1 week and 3 and 6 months after their placement, using the California Dental Association (CDA) quality-evaluation index. Their functional wear and color stability were also evaluated. Data were analyzed by using nonparametric statistics (α=.05).

Results: The CDA criteria showed that the PMMA group performed better than the POM group in the surface and color parameter (P<.05). Fractures at the implant connection level were observed in 10 prostheses. The number of fractures was significantly higher in internal conical connection implants (P<.05). The statistical analysis of color stability showed values of ΔE*ab of 7.18 for PMMA and 8.58 for POM, without significant differences between materials. Concerning the wear evaluation, a significant increase in the wear of both materials was found at 6 months of functioning (P<.05). No significant differences were found within materials.

Conclusions: Within a 6-month observation period, PMMA interim implant-supported FPDs performed better than POM in the surface and color parameter. Entirely polymer posterior implant-supported FPDs with internal conical connection implants appear to be more susceptible to fracture.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Computer-Aided Design
  • Dental Implants*
  • Dental Prosthesis Design
  • Dental Prosthesis, Implant-Supported*
  • Dental Restoration Failure
  • Denture, Partial, Fixed
  • Humans

Substances

  • Dental Implants