Immediate Occlusal Loading of Freestanding Implants Using Cortical Satellite Implants: Preliminary Report of a Prospective Study

Immediate Occlusal Loading of Freestanding Implants Using Cortical Satellite Implants: Preliminary Report of a Prospective Study
March 2005
Engelke, Wilfried MD*; Decco, Oscar A. DDSÇƒÜ; de las Mercedes Capobianco, Mar??a BioingÇƒ?; Schwarzw?ßller, Wolfgang Dr. rer. nat.¨?; Villavicencio, Milagros Mendoza DDS¨?
Implant Dentistry: Volume 14
Abstract TOP
Freestanding implants with mandibular overdentures are used frequently after 3 months' healing time. Immediate full loading may be applied to this approach if sufficient primary stability is provided. The present study evaluates the success rate of two single-standing interforaminal implants stabilized with cortical satellite implants and loaded immediately with overdentures. Twenty patients (five male and 15 female; age, 45-87 years) received two single-standing titanium screw implants (Semados, Bego, Bremen, Germany). All implants were stabilized during healing time with cortical satellite implants (2.0-mm bone screws; Medartis, Basel, Switzerland) via individual connectors attached to the implant abutment subgingivally. Mandibular overdentures were incorporated immediately after surgery using ball attachments as retentive elements. The patients were under no restrictions concerning diet and loading. The satellite implants were removed after 3 months. All implants were osseointegrated after 10 months' mean observation time. The mean Periotest value was -4.9, and the mean marginal bone loss was 0.7 mm. No dropouts were observed, and 19 of 20 patients would recommend the treatment to a close friend. Preliminary follow-up data indicate that cortical stabilization of two anterior mandibular implants with satellite implants leads to osseointegration of the implants under immediate load conditions with an overdenture. This concept contributes to reduction of prosthetic treatment costs and permits immediate enhancement of masticatory function.
The predictability of implants with an unloaded healing period is well documented.1 In the past, a healing period of 3 to 6 months for adequate osseointegration was recommended before functional loading of an implant. Using two interforaminal implants with a conventional healing protocol, long-term success has been reported in a series of studies.2
Many researchers have advanced the idea of immediate implant placement as well as immediate loading of dental implants. The studies of Ledermann3 in 1979 gave evidence that titanium screw implants in cortical bone in the anterior mandible can be loaded immediately with high success rates, although this concept was not accepted widely by therapeutic guidelines in the past. Schnitman et al 4 in 1990 also evaluated immediate loading and published a 10-year follow-up report in 1997, which revealed an 85% success rate in the anterior mandible with Br?ïnemark implants.
The use of titanium screw implants in the anterior mandible has been reported primarily for splinted implants3,5-7 with high long-term survival rates. Based on an 18-month follow-up study of immediately functional loaded Br?ïnemark implants, Randow et al 8 concluded that it was possible to successfully load dental implants via permanently fixed rigid cross-arch suprastructures in the edentulous interforaminal area.
Br?ïnemark et al 9 recently presented a concept of same-day teeth using prefabricated bars within a template-guided surgical protocol and only three interforaminal titanium screw implants. The first results of the Br?ïnemark study show a 98% success rate after 3 years in 270 implants placed in 90 patients. Using the Br?ïnemark Novum (Nobel Biocare, Gothenburg, Sweden) concept, patients received a removable mandibular bar-retained prosthesis within 7 hours.
Payne et al 10 described an approach with only two interforaminal implants that were loaded after only 2 weeks. The authors reported no failure during the first year of observation in 24 patients with two different implant systems.
However, the aim of immediate loading of dental implants presents a number of challenges based on the anatomy and density of bone available for implant placement, particularly if the implants are not splinted with a connecting bar. As reported by Brunski et al,11 a useful clinical guideline is that much will depend on the inherent stability of the implant when first placed in its site and loaded.
Engelke and Jacobs12 proposed a new concept in immediate loading using cortical satellite implants, which are based on well established treatment concepts in general traumatology, by using fixation screws anchored firmly in cortical bone.13
In the case of immediate loading, an implant must withstand masticatory forces and moments during the period of remodeling without exceeding critical micromovement of the implant relative to the surrounding bone. The critical amount of micromovement during the healing period is defined as 100 micrometers.11
In vitro studies revealed14 that satellite implants enhance the stability of dental implants in fresh extraction sites significantly. Based on the in vitro data as well as on successful clinical application in various indications,12 the authors started a prospective controlled clinical study on immediate loading of freestanding implants in the mandible. In the present report, preliminary data are presented up to 29 months of observation.
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