Immediate/Early Loading

Abstract: Background: The concept of immediate loading of root-form implants for fixed restorations has received increasing interest over the last 5 years. Several authors have commented on parameters that may influence results, including implant number, implant length, bone density, and patient habits. The trigger for bone remodeling around an implant may occur from the surgical trauma of insertion or the mechanical environment of strain at the interface. In the classic two-stage approach, these were divided episodes, separated by 3 to 6 months. Immediate loading compresses this time frame; the two driving mechanisms for bone repair occur concurrently. A scientific approach to the interface development is to match the bone healing response of trauma (woven bone of repair) to the response of mechanical load (reactive woven bone), so the sum of these two entities does not result in fibrous tissue formation and clinical mobility of the implant. Purpose: It is the purpose of this article to review the scientific rationale of these statements and coordinate them to bone physiology and bone biomechanics. Materials and Methods: Findings from previous reports in the literature were reviewed and summarized to form the basis of a prospective study using a bone quality-based implant system (Biohorizons, Maestro Dental Implants, Birmingham, AL, USA). A transitional prosthesis was delivered either on the day of surgery or within 2 weeks for 30 patients and 31 arches. A total of 244 implants were used to support these restorations, for an average of 7.8 implants per prosthesis. After 4 to 7 months, the final restorations were fabricated. One year after the final restoration was loaded, the implant survival was 100%; the 31 restorations also had a survival of 100% over this time frame. This report presents these implants and restorations over a 1- to 5-year period, with an average follow-up period of 2.6 years. Results: The bone loss from implant insertion to final prosthesis delivery averaged 0.7 mm. The first-year bone loss after final prosthesis delivery averaged 0.07 mm. A slight increase in bone height was observed after the first year, but generally no increase was observed over the remaining evaluation period. Conclusions: In the current report, no implant failure occurred, and crestal bone loss values were similar to or less than values reported with the conditional two-stage approach. This may be related to the number and position of implants, implant design, and/or the surface condition of the implant loading.

Abstract: Background: Conventional prosthetic treatment of the edentulous and resorbed maxilla with zygomatic implants is a lengthy procedure. Today, immediate/early loading is a clinical reality and it is possible that such protocols could be used also for zygomatic implants. Purpose: The aim of the present study is to report on the clinical outcomes of immediate/early loading of zygomatic implants for prosthetic rehabilitation of edentulous and severely resorbed maxillary cases. Materials and Methods: A total of 47 zygomatic and 129 regular implants were placed in 25 consecutive patients with total (N = 23) or partial (N = 2) edentulism in the maxilla. The patients had less than 4 mm of available bone height and width distal to the canine pillars. Straight and angulated abutments and impression copings were attached to the implants during surgery. Impressions and bite registrations were made and 19 patients received a bridge within 24 hours and six patients were rehabilitated within 5 days. Screw-retained full arch restorations were used in 23 patients and cemented in 2 patients. The patients were instructed for a soft diet during 4 months. Follow-up controls were performed at 1, 4, and 12 months and thereafter annually. All patients were followed for at least 2 years and up to 5 years in function. Results: All zygomatic implants were stable during the follow-up (cumulative survival rate 100%). One regular implant placed in the pterygoid plate failed after 52 months of loading (cumulative survival rate 99.2%). Apart from fracture of one abutment screw and of anterior teeth in five patients, no other complications were noted. Conclusions: Within the limitations of the present study, it is concluded that immediate/early loading is a viable treatment modality for prosthetic rehabilitation of the severely resorbed maxilla using zygomatic and conventional implants.

Abstract: Two previous reviews have evaluated the clinical outcomes of immediate/early loading of dental implants based on studies published until 2005.(1,2) The aim of the present paper was to review controlled clinical studies on the subject published since 2005 including at least 10 patients in each group followed for at least one year in function. Six comparative studies were found and none of these showed any differences in survival rates or marginal bone loss after one to five years. Most authors used specified inclusion criteria to avoid known risk factors such as soft bone, short implants and bruxism. Data from one randomized study in the edentulous maxilla showed no differences between early and delayed loading in consecutive clinical routine cases including short implants and soft bone. Three additional studies comparing different surfaces or implant designs under immediate loading were reviewed. No differences between implants with a moderately rough or smooth surface topography were observed. The data add to the previous bulk of evidence that various designs of implants can be loaded shortly after their placement in both the mandible and the maxilla. However, one study reported on marginal bone loss around a novel one-piece implant design leading to implant failure which was not seen for control two-piece implants.(3).