Douglas Dederich BSEE, DDS, MSc, PhD, Cert. Perio.
Immediate and delayed implant placement show equally high survival rates.
Although this review suggests that immediate implant replacement may be a viable clinical option, the review itself was poorly conducted, presenting heterogeneous evidence of limited quality.
In patients having a tooth extracted, do immediate implants compared to delayed implants lead to better clinical outcomes?
The authors conducted a search of two electronic databases for articles published in English from 2004 to November of 2009. The review included studies of patients who needed tooth extraction due to periapical infections, unrestorable caries, trauma and periodontal disease, with a minimum of 12 months follow-up and 10 implants. Outcomes assessed were immediate implant survival and success rates; position of the mucosal margin; mean distance from buccal bone to lingual bone; marginal bone resorption; bone loss; and implant stability. Where possible, success rates were defined according to Albrektsson et al. , which includes absence of mobility, pain, peri-implant infection and suppuration as well as no circumferential radiolucencies.
The search produced 135 titles to which the authors applied the inclusion and exclusion criteria mentioned above, leaving 20 articles. Of those studies, 11 were prospective clinical trials, seven were randomized clinical trials and two were controlled clinical trials. The studies included a total of 1,139 implants utilizing approximately 12 variations of hardware with 12 to 60 months follow-up. Eight assessed recession and 15 assessed bone loss. Due to the heterogeneity of the data, the authors could not perform a meta-analysis. They found no obvious clinical differences in recession or bone loss in the data presented. Survival rates were comparable between immediate and delayed implants.
There is not enough reliable evidence to prove higher success using immediate implant placement over delayed placement. Immediate implants have survival rates similar to delayed implants.
Source of Funding:
Importance and Context:
When planning to replace an extracted tooth with a dental implant, the clinician must decide between immediate or delayed implant placement protocols. Having evidence of the advantages and disadvantages of each protocol will assist the clinician in making this decision and in managing patient expectations in regards to clinical outcomes, time of treatment, and expense.
Strengths and Weaknesses of the Systematic Review:
The review authors summarized the included articles, but failed to draw conclusions to most of the questions that they asked, which would have made this review more meaningful to the reader. They did not search the grey literature or complete a hand-search of the literature and only included articles published in English. The inclusion criteria were vague, and it was not clear whether they were consistently applied throughout the review. Further, the rationale for a minimum of 10 implants was not clearly explained. The exclusion criteria also were vague and confusing, as they appear to omit groups intended for comparison within this review (i.e., delayed implants). In addition, the authors did not attempt to assess the quality of the selected studies or analyze the risk of bias. They acknowledged the heterogeneity of the data and made an important distinction between survival and success rates. However, they made no distinction between anatomic locations (i.e., bone type and anatomy) or differences in hardware. It was also not clear whether independent evaluators were used to select the included studies or how disagreements were managed. The authors did not address publication bias or state conflicts of interest.
Strengths and Weaknesses of the Evidence:
The authors compared patient-centered outcomes data, relating primarily to function and esthetics, and distinguished between clinical survival and clinical success. They did not define short term vs. long term nor did they describe the distribution of the durations of the included studies. Only 8 of the studies directly compared immediate (123 implants) with delayed (116 implants) representing only 239 implants of the 1,139 implants included. There was also no evidence of blinding of the evaluators, increasing the risk of confirmational bias. While the evidence of high survival rates is convincing, the evidence of long-term outcomes that relate to esthetics is poor, primarily because of its scarcity.
Implications for Dental Practice:
Immediate implant placement may be a viable clinical option to replace an extracted tooth. While immediate implants may conveniently avoid the cost of surgery, we do not have convincing evidence that they offer equivalent or superior esthetic results compared to delayed implant placement. Since patient expectations are an important factor in their satisfaction, it would seem important to inform the patient of this lack of evidence during the treatment planning phase and to take their risk tolerance of a less than ideal esthetic result into account.  Albrektsson T, Zarb G, Worthington P, Eriksson AR. The longterm efficacy of currently used dental implants: a review and proposed criteria of success. Int J Oral Maxillofac Implants. 1986; 1:11-25.
*Support for this Critical Summary was provided by a grant from the Canadian Institutes of Health Research*