Stacy Geisler DDS, PhD
Trends (no statistically significant differences) suggest that immediately loaded implants fail more often than those conventionally loaded, but less commonly than those early loaded.
The authors did not find a statistically significant difference between the treatment modalities based on data from 22 randomized controlled trails.
Are dental implants that are restored immediately (within one week) or early (within two months) as successful as implants that are restored conventionally (after two months)? Does occlusal loading of immediate or early restored implants effect success?
The authors conducted an all-language electronic search of four databases for literature published through June 4, 2008. They only considered randomized controlled clinical trials that compared dental implants that were loaded immediately (within one week) or early (within two months) with dental implants that were loaded conventionally (after two months). All studies must have had a follow-up of at least four months. To ensure that all eligible, unpublished trials were located, the authors contacted 55 implant manufacturers. Study outcome measures included prosthesis failure, implant failure, and evidence of radiographic marginal bone loss. The authors performed meta-analysis using random effects modeling. Because of an insufficient number of studies, they were unable to adjust for type of bone and anatomy (mandible vs. maxilla) as well as number of implants placed per participant and type of restoration (single restoration vs mandibular overdenture). In addition, the authors did not adjust for torque insertion at time of implant placement. To determine risk of bias, they completed quality assessments of each trial.
The authors identified 30 randomized controlled clinical trials, of which 22 (1024 total subjects) met all inclusion and exclusion criteria. Twelve trials compared immediate versus conventional loading, three trials compared early versus conventional loading, six trials compared immediate versus early loading, and one trial compared occlusal versus nonocclusal loaded dental implants. The authors determined low risk of bias in six of the 22 included trials. The meta-analyses suggested a trend that immediately- and early-loaded implants had a higher risk of failure as compared to conventionally loaded implants. However, the authors were unable to demonstrate statistical equivalence between any of the study interventions.
The authors concluded that it is possible to successfully load dental implants immediately or early after their placement in selected patients, though not all clinicians may not achieve optimal results.
Source of Funding:
School of Dentistry, The University of Manchester, UK.
Importance and Context:
Brånemark essentially established the gold standard for conventional loading methods. (1) To minimize risk of soft tissue encapsulation at the implant/bone interface through micro-movement of the implant during healing, Brånemark suggested that after placement, mandibular and maxillary implants should not be loaded for three to four months and six to eight months, respectively. Because of developments in implant design and surface texture, Brånemark’s more recent studies have suggested that implants placed in mandibular bone can be loaded early or immediately, in selected patients (2). Defining and standardizing protocols for immediate and early loading of dental implants is a high priority for two reasons: 1) immediate and early loading of dental implants can lead to superior outcomes, especially in the esthetic zone and, 2) immediate and early loading of dental implants can increase overall patient satisfaction by decreasing treatment time. Immediate loading of a single implant in the maxillary esthetic zone can optimize papillary soft tissue response through the support of the biologic width of the dental implant/restoration complex (3). Overall treatment time also is decreased. Patient demand continues to grow for immediate restoration of dental implants. Patient satisfaction increases as restoration time decreases (4). However, the loss of an implant and/or prosthesis can be costly to a patient. Also, a procedure that needs to be redone can increase the treatment time and cost. Thus, the practitioner should balance the patient’s desire for quick restoration with reliable and predictable treatment methods that minimize risk of failure.
Strengths and Weaknesses of the Systematic Review:
The authors used acceptable methods to conduct their literature search, which was well-defined with appropriate inclusion and exclusion criteria. They conducted and exhaustive search of the grey literature. Their use of random effects modeling to adjust for heterogeneity within the various study designs also was a strength.
Strengths and Weaknesses of the Evidence:
The evidence presented in this review does not support or refute early and immediate loading as compared to conventional loading of dental implants.
Implications for Dental Practice:
The goal of this review was to demonstrate whether early or immediate loading of dental implants is as successful as conventional loading. The authors did not find a statistically significant difference between the treatment modalities. The estimates of failure rates (relative risk data) suggests that the risk associated with immediate and early loading is higher than with conventional loading. Until further evidence is available, caution should be exercised in following immediate or early loading protocols, especially by the inexperienced operator.
1. Brånemark P-I, Hansson BO, Adell R et al. Osseointegrated implants in the treatment of edentulous jaw. Experience from a 10-year period. Stockholm: Almqvist & Wiksell International, 1977.
2. Brånemark P-I, Engstrand P, Ohrnell LO, et al. Brånemark Novum: A new treatment concept for rehabilitation of the edentulous mandible. Preliminary results from a prospective clinical follow-up study. Clin Implant Dent Relat Res 1999;1:2-16.
3. Oh TJ, Shotwell JL, Billy EJ et al. Effect of flapless surgery on soft tissue profile: a randomized controlled clinical trial. J Periodontolo 2006; 77(5):874-82.
4. Schropp L, Isidor F. Clinical outcome and patient satisfaction following full-flap elevation for early and delayed placement of a single tooth implants: a 5-year randomized study. Int J Oral Maxillofac Implants. 2008 Jul-Aug; 23(4):733-43.