When high primary stability is achieved, immediate and early loading protocols have been reported safe and successful in the scientific literature.
In this section, you will find summaries on documentation of immediate and early loading using the Astra Tech Implant System'".
Immediate mandibular rehabilitation with endosseous implants: simultaneous extraction, implant placement, and loading
Purpose: This study was established to determine the clinical outcome and implant survival when extracting teeth, placing implants and immediately loading them with either screw-retained or cemented acrylic resin fixed dentures.
Materials and Methods: Ten healthy edentulous patients were enrolled in to the study. All patients underwent the initial fabrication of a fully extended upper denture and a short span acrylic denture (second premolar to second premolar), set up on mounted and articulated diagnostic master casts on a semi-adjustable articulator. The mandibular dentures were further amended at time of surgery. Prior to processing an interocclusal record was fabricated to record the relationship between the maxillary and mandibular prostheses.
During surgery patients underwent dental clearance, alveolectomy and implant placement (TiOblast'v 3.4, 4.0) according to manufacturer's protocol and under antibiotic prophylaxis. Extra attention was paid to achieving parallelism to aid prosthesis location. Only implants achieving a good primary fixation were included for immediate loading, otherwise cover screws were placed to allow for submerged healing. For all other implants, modified transmucosal healing abutments were secured into the implants and the mucoperiosteal flaps repositioned and sutured. Modified healing abutments were subsequently used for customization or were replaced by prefabricated screw retaining abutments. Mandibular dentures were hollowed out and located utilizing the distal flanges and the occlusal relation with the new upper denture. The customized abutments or bridge cylinders were captured in the denture using autopo-lymerizing resin. Dentures were removed, trimmed appropriately and polished before cementation or being secured into place by bridge screws.
Patients were asked to keep to a liquid diet for one week and to use chlorhexidine rinses. Soft diets were required during weeks 2 and 3 postoperatively. After 21 days of healing patients diets were unrestricted. All patients were definitively restored with acrylic/ gold screwretained prostheses after 3 months.
Results: A total of 54 implants were placed, of which 48 achieved good primary fixation and were utilized for an immediate loading protocol.
Healing was uncomplicated for all patients and all reported minimal discomfort. At the 3 month appointment all submerged implants which had been exposed and the immediately loaded implants were immobile and there was a 100% baseline survival. Bone levels were seen to remain close to the top of the implant at the implant-to-abutment junction.
The only recorded complications were fracture of the provisional bridge in two patients, debonding of the fixed denture in the same two patients and a fractured acrylic tooth in one patient.
Discussion: In the current study an immediate loading protocol was adopted, such that the implants were provisionally restored within hours of placement allowing for an immediate but progressive loading of the implants, controlled by strict instruction regarding diet. Interestingly in the current study no effort was made to over-engineer the cases to provide insurance against implant failures, such that each patient received typically 5 to 6 implants, of which a minimum of 4 were used to support the immediate provisional bridge. This was considered possible in light of previous reports of high success with immediate loading and in recognition of the advantages of using a micro-roughened implant surface, since this is known to aid clot retention, improve primary stability and optimize osseointegration.
The study also demonstrates the efficacy of using a two piece modular implant for a one-stage procedure, thereby allowing abutment changes to accommodate shrinkage of soft tissues prior to fabrication of the definitive prostheses, and submergence of those implants which do not attain good immediate primary fixation.
Astra Tech
BioManagement Complex 
