Outcomes of root canal treatment and restoration, implant-supported single crowns, fixed partial dentures, and extraction without replacement: a systematic review.

STATEMENT OF PROBLEM: Dentists and patients are regularly confronted by a difficult treatment question: should a tooth be saved through root canal treatment and restoration (RCT), be extracted without any tooth replacement, be replaced with a fixed partial denture (FPD) or an implant-supported single crown (ISC)? PURPOSE: The purpose of this systematic review was to compare the outcomes, benefits, and harms of endodontic care and restoration compared to extraction and placement of ISCs, FPDs, or extraction without tooth replacement. MATERIAL AND METHODS: Searches performed in MEDLINE, Cochrane, and EMBASE databases were enriched by hand searches, citation mining, and expert recommendation. Evidence tables were developed following quality and inclusion criteria assessment. Pooled and weighted mean success and survival rates, with associated confidence intervals, were calculated for single implant crowns, fixed partial dentures, and initial nonsurgical root canal treatments. Data related to extraction without tooth replacement and psychosocial outcomes were evaluated by a narrative review due to literature limitations. RESULTS: The 143 selected studies varied considerably in design, success definition, assessment methods, operator type, and sample size. Direct comparison of treatment types was extremely rare. Limited psychosocial data revealed the traumatic effect of loss of visible teeth. Economic data were largely absent. Success rates for ISCs were higher than for RCTs and FPDs, respectively; however, success criteria differed greatly among treatment types, rendering direct comparison of success rates futile. Long-term survival rates for ISCs and RCTs were similar and superior to those for FPDs. CONCLUSIONS: Lack of comparative studies with similar outcomes criteria with comparable time intervals limited comparison of these treatments. ISC and RCT treatments resulted in superior long-term survival, compared to FPDs. Limited data suggested that extraction without replacement resulted in inferior psychosocial outcomes compared to alternatives. Long-term, prospective clinical trials with large sample sizes and clearly defined outcomes criteria are needed.

Levels of evidence for the outcome of nonsurgical endodontic treatment.

The purpose of this systematic review was (a) to search for clinical articles pertaining to success and failure of nonsurgical root canal therapy, and (b) to assign levels of evidence to these studies. Electronic and manual searches were conducted to identify studies published between January 1966 and September 2004 with information on the success and failure of nonsurgical root canal therapy. Articles were reviewed and graded for strength of level of evidence (LOE) from one (highest level) to five (lowest level). This review resulted in the identification of 306 clinical studies related to this topic area. Six articles were randomized controlled trials (RCTs, LOE 1). This search also identified 12 low-quality RCTs (LOE 2), 14 cohort studies (LOE 2), five case-control and eight cross sectional studies (LOE 3), four low-quality cohort studies (LOE 4), and five low-quality case-control studies (LOE 4). The majority (73) of the often-quoted "success and failure" studies were case series (LOE 4). The rest of the articles were descriptive epidemiological studies (42), case reports (114), expert opinions (18), literature reviews (4), and one meta-analysis. Based on these findings, it appears that a few high-level studies have been published in the past four decades related to the success and failure of nonsurgical root canal therapy. The data generated by this search can be used in future studies to specifically answer questions and test hypotheses relevant to the outcome of nonsurgical root canal treatment.