A Moderately Favorable Five-Year Success Rate for Resin-Bonded Bridges
Heather K. Hill, DDS,
David Landwehr, DDS, MS and
Steven Armstrong, DDS, PhD
 |
Clinical questions.
|
|---|
What is the long-term survival rate of resin-bonded bridges (RBBs)? What is the incidence of specific technical and biological complications across an observation period of at least five years?
|
Review methods.
|
|---|
From a MEDLINE and hand search of the literature from January 1965 through January 2007, two independent reviewers identified 17 studies that met their inclusion criteria. To be included, studies were required to have involved a mean follow-up period of five years or more, have included a clinical examination as part of the follow-up examination and have included a description of suprastructure characteristics. The authors did not identify any randomized controlled trials; nine studies were prospective and eight were retrospective. The authors defined an RBB’s survival as remaining in situ at the final examination without multiple debondings, irrespective of its condition. They defined technical complications as the RBB’s loss of retention or as a fracture of the veneer with or without loss of the reconstruction. Finally, they defined biological complications as caries in abutment teeth or periodontal disease progression. Four independent reviewers screened the search results, with two reviewers performing the data extraction. The authors grouped the data from all studies and analyzed failure and complication rates using random-effects Poisson regression models to obtain summary estimates of five-year proportions.
|
Main results.
|
|---|
The search yielded 6,110 titles and 214 abstracts. The authors performed a full-text analysis of 93 articles, which resulted in 17 studies that met the inclusion criteria. Meta-analysis of these studies estimated an RBB survival rate of 87.7 percent (95 percent confidence interval [CI], 81.6–91.9 percent) after five years. The most frequent complication was debonding (loss of retention), which occurred in 19.2 percent (95 percent CI, 13.8–26.3 percent) of RBBs during an observation period of five years. The annual debonding rate for RBBs placed on posterior teeth (5.0 percent) tended to be higher than that for those placed on anterior teeth (3.1 percent). Biological complications, such as caries in abutment teeth and RBBs lost owing to periodontitis, occurred in 1.5 percent of abutments and 2.1 percent of RBBs, respectively.
|
Conclusions.
|
|---|
The estimated survival rate of RBBs was compromised by a high debonding rate. Therefore, dentists may need to schedule a substantial amount of extra chair time after the placement of RBBs. Studies with a follow-up of 10 years or more are needed to evaluate the long-term outcomes of RBBs.
|
COMMENTARY
|
|---|
Importance and context.
Since the early 1970s, practitioners have used RBBs as a conservative option for fixed reconstruction of missing teeth. Yet, they commonly consider RBBs to be transitional prostheses, owing to the bridges’ low survival rates and frequent debonding. Consequently, knowing the treatment outcomes of RBBs provides important information for treatment planning and informed consent.
Strengths and weaknesses of the systematic review.
The authors performed a comprehensive search of only one electronic database (MEDLINE) and did not state whether they had established the inclusion criteria in advance of conducting the search. The authors did not explicitly define the inclusion criteria "superstructures." The reviewers used accepted methods to select articles, but they inappropriately aggregated the results of all the selected studies rather than examined prospective and retrospective studies separately. They did not report a formal review of the validity of each study. Stratification was not possible, and combining the studies may have introduced further heterogeneity into the results because every study reported a unique combination of RBB location, design, construction and cementation method. The fact that multiple studies lost substantial numbers of subjects to follow-up is of concern. All of these issues likely led this review’s authors to a significant overestimate of the RBB’s longevity.
Strengths and weaknesses of the evidence.
In the absence of randomized controlled trials, this review was limited to lower levels of evidence from nine prospective and eight retrospective studies. However, investigators in all the studies reported results regarding debonding, and those in 12 of the 17 studies reported results regarding survival (definitions of which varied between studies). The investigators conducted these studies primarily in institutional and specialized settings, and the outcomes may be different in a general dentist’s private practice.
Implications for dental practice.
The review suggests that RBBs—which the authors estimated to have an 87.7 percent five-year survival rate—are a treatment alternative to conventional bridges and implant-supported crowns. In another review, Pjetursson and colleagues1 estimated these alternatives to have a 93.8 percent and a 94.5 percent five-year survival rate, respectively. However, given the analytical methods used, all of these numbers may be overestimates. Hence, clinicians should use care in treatment planning and should obtain informed consent before placing RBBs.
|
FOOTNOTES
|
|---|
A critical summary of Pjetursson BE, Tan WC, Tan K, Brägger U, Zwahlen M, Lang NP. A systematic review of the survival and complication rates of resin-bonded bridges after an observation period of at least 5 years. Clin Oral Implants Res 2008;19(2):131–141.
Systematic review conclusion. The authors’ estimated 87.7 percent survival rate of resin-bonded bridges after five years is complicated by a 19.2 percent debonding rate of the veneers.
Critical summary assessment. The authors may have overestimated the survival rate because they inappropriately aggregated the results of prospective and retrospective studies and a significant number of subjects were lost to follow-up.
Evidence quality rating: Limited.
Dr. Hill is a National Library of Medicine fellow, Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Biomedical Information Communication Center, 3181 S.W. Sam Jackson Park Road, Portland, Ore. 97239, e-mail "hillhe{at}ohsu.edu". She also is an evidence reviewer for the American Dental Association. Address reprint requests to Dr. Hill.
Dr. Landwehr maintains a private practice in Madison, Wis. He also is an evidence reviewer for the American Dental Association.
Dr. Armstrong is an associate professor, Department of Operative Dentistry, College of Dentistry, University of Iowa, Iowa City. He also is an evidence reviewer for the American Dental Association.
The systematic review described here was funded by the Clinical Research Foundation for the Promotion of Oral Health, University of Berne, Switzerland. W.C. Tan received a clinical scholarship from the International Team for Implantology (ITI) Foundation for the 2006–2007 academic year.
Critical Summaries is supported by grant 1 G08 LM008956 from the National Library of Medicine and the National Institute of Dental and Craniofacial Research.
These summaries, published under the auspices of the American Dental Association Center for Evidence-Based Dentistry, are prepared by practitioners trained in critical appraisal of published systematic reviews who work under the mentorship of experts. The summaries are not intended to, and do not, express, imply or summarize standards of care, but rather provide a concise reference for dentists to aid in understanding and applying evidence from the referenced systematic review in making clinically sound decisions as guided by their clinical judgment and by patient needs.
For more information on the evidence quality rating provided above and additional critical summaries, please visit "http://ebd.ada.org".
|
REFERENCES
|
|---|
- Pjetursson BE, Brägger U, Lang NP, Zwahlen M. Comparison of survival and complication rates of tooth-supported fixed partial dentures (FPDs) and implant supported FPDs and single crowns (SCs) (published correction appears in Clin Oral Implants Res 2008;19[3]: 326–328). Clin Oral Implants Res 2007;18(suppl 3):97–113.[Medline]
TOP
Clinical questions.
Review methods.
