Analia Veitz-Keenan DDS
Evidence suggests that mandibular implant-supported dentures satisfy edentulous patients more than conventionally supported dentures do, but it is inconclusive whether the technique also improves oral and general health-related quality of life.
In edentulous patients, do mandibular implant–retained dentures as compared with conventionally supported dentures improve patient satisfaction, as well as oral and general health-related quality of life?
The authors followed QUORUM guidelines to conduct their systematic reviews. They electronically searched four databases for articles published in any language from 1966 to 2007. Two reviewers independently screened and selected titles and abstracts for review. Selected journals were hand searched. The authors’ search identified relevant randomized controlled trials (RCT) in which edentulous individuals wore either mandibular implant-supported dentures or conventional dentures. The outcomes assessed included patient satisfaction, oral and general health-related quality of life and a minimum follow-up time of two months. The authors rated as “adequate,” “inadequate” or “unclear” the methodological quality (sequence generation, concealment of allocation and handling of withdrawals and loses) of each selected RCT. One investigator used an extraction form to abstract data that was crosschecked by a second reviewer. Acceptable statistical principles were followed for the data statistical analysis.
The authors identified 2,262 articles, of which 37 were selected for full-text searching. Of the 10 manuscripts that met the inclusion criteria, seven were RCTs. The other three manuscripts reported data from the same RCT. All included studies used a parallel design with two arms, except for one with (three arms). In all trials but one, two supporting implants were placed in the mandible. Dentures were retained by clip attachment to a bar or to a ball attachment. In all trials, participants also received conventional maxillary dentures. Follow-up periods ranged from two months to 10 years. For follow-up periods of two months and 24 months, dropout rates ranged from 4 percent to to 55 percent, respectively. Sample sizes varied from 60 to 157. Different implant systems were used. Implant-supported dentures appeared to generate more satisfaction (Effect size [ES]: 0.80; 95 percent confidence interval [CI], 0.36 to 1.24) but no effect on the oral health-related quality of life (ES:-0.41; 95 percent CI, -1.02 to 0.20). The authors identified only one article that measured general health-related quality of life.
Mandibular implant-supported dentures are more satisfying to patients than conventional dentures. There is limited evidence they may improve a patient’s oral and general health-related quality of life.
Source of Funding:
Principal investigator previously was funded by university, as well as industry. This individual also participated in two of included RCTs.
Importance and Context:
Patient satisfaction with mandibular prosthesis can be achieved through good retention and stability. In unfavorable cases in which bone-supported retention is limited, implant- supported dentures present a good solution. A significant body of literature has investigated the benefits/drawbacks of this approach, but a comprehensive and systematic review of studies (including only RCTs) currently is unavailable.
Strengths and Weaknesses of the Systematic Review:
The authors followed accepted guidelines for conducting a systematic review. They satisfied the most important principles. Their well-conducted search included an extensive hand search. They thoroughly assessed study quality using randomization, allocation concealment completeness of follow up, and intention to treat analysis (ITT). They calculated effect sizes by combining (meta-analysis) results across studies. Effects were expressed as standard mean differences.
Strengths and Weaknesses of the Evidence:
The review included only a few RCTs. The statistical analysis was only performed in studies that reported the same outcome measure. Nevertheless, substantial statistical heterogeneity (differences between the reported outcomes in the included RCTs) was revealed. Some of the longer studies had significant dropout rates. Regarding patient satisfaction, a large positive effect was found and was statistically significant. For oral health quality of life, a positive trend was found for the mandibular implant supported dentures.
Implications for Dental Practice:
Although implant-supported mandibular dentures appear to produce more patient satisfaction than do conventionally supported dentures, no conclusive impact was identified regarding oral and general health-related quality of life improvements. The authors did not quantify treatment cost and long term success, which are key factors in the decision-making process.