Alika Yu DDS
For mandibular implant overdentures (IOD), the presence of antagonistic teeth is not a risk factor for failure. However, for maxillary IOD, the presence of antagonistic teeth might be a risk factor for failure.
The conclusions of this review are based on the authors' verbal summary of the included studies and not a formal analysis of the findings.
In patients receiving implant overdentures, does the presence of antagonistic teeth influence the survival rate of the implant overdenture?
The authors searched one electronic database and hand-searched two university libraries for articles published in English from 1990 to 2009. Their search included clinical studies or reviews about treatment of edentulous jaw with implant overdenture opposing natural dentition, implant overdenture, fixed partial denture, removable partial denture, root overdenture, implant fixed prosthesis, or complete denture. They excluded studies that had inadequate determination of opposing arch, fewer than 10 patients and less than two years of observation time.
The initial electronic and manual searches yielded a total of 206 articles (204 electronic, two manual), 20 of which the authors selected for review. They selected 10 studies of mandibular arches, and 10 studies of maxillary arches. The observation periods for mandibular IOD studies ranged from 43 months (survival rate of 100 percent) to 144 months (survival rate not listed). For the maxillary IOD, the observation period ranged from 29 months (survival rate of 79%) to 120 months (survival rate of 86.1%) . The authors noted that the varying effects of exiting remaining teeth in the maxillary and mandibular arch on opposing IOD. In the authors' global assessment, the remaining natural maxillary teeth were not a risk factor to the mandibular IOD. However, the remaining natural mandibular teeth seemed to negatively affect the maxillary IOD.
The presence of antagonist teeth does not seem to be a risk factor for mandibular implant overdenture failure. However, for maxillary IOD success, the presence of antagonistic teeth might be a risk factor, but not a contraindication.
Source of Funding:
Importance and Context:
Implant overdentures improve denture stability and patient satisfaction as compared with conventional complete dentures.1,2 But studies have reported about the difficulty of fabricating a denture that fits well with the opposing natural dentition.3 The presence of opposing natural teeth may affect the success of an implant overdenture.
Strengths and Weaknesses of the Systematic Review:
The authors used accepted methods to identify relevant studies. They included tables of evidence summary. However, no quality assessment of included studies or combinability of studies was conducted. They failed to specify the number of authors who conducted the search and review; they did not address the possibility of language or publication biases; and they searched only one electronic database for relevant studies.
Strengths and Weaknesses of the Evidence:
The review was undermined by the absence of available high quality and informative original studies. Although the authors selected 20 studies, not one of the studies provided data about the relationship between antagonistic teeth and implant success; only five studies discussed the relationship between the natural teeth and the opposing implant overdenture; and one study observed an increased number of prosthetic failures of maxillary IOD with opposing natural mandibular dentition. These limitations precluded the authors from conducting formal analysis of the relationship between the presence of antagonistic teeth and implant success.
Implications for Dental Practice:
There is a lack of available scientific evidence on the effects of antagonistic teeth on implant overdenture survival. As a result, practitioners must solely base their treatment decision on each patient's clinical presentation. Practitioners, when determining whether antagonistic teeth will affect implant success, must consider their skills and experience, their patient's oral and general health status, and their patient's preferences.