Peri-implant bone reactions to immediately loaded implants. An experimental study in monkeys

BACKGROUND

There are reports which demonstrate that immediately loaded splinted implants can be osseointegrated when they are placed in the anterior part of the lower jaw. The concept of immediate loading has not been well investigated in the posterior mandible. The aim of this study was to evaluate the bone reactions around immediately loaded implants placed in the posterior region of the lower jaw in the monkey model.

METHODS

Six adult Macaca fascicularis monkeys were used in this study. A total of 36 implants were placed after extraction of the second premolars, first and second molars, and complete healing of the sockets. Three control (C) group implants were placed in one quadrant of the lower jaw of each monkey. After a delay of 3 months to allow osseointegration to take place, the implants were loaded for 1 month using temporary resin bridges and later for 2 months using metal splinted crowns. In the contralateral region of the lower jaw, 3 test (T) group implants were placed and loaded immediately with the same sequence as carried out for the C implants. Specimens were examined and evaluated histologically after sacrifice.

RESULTS

All of the implants were osseointegrated. Compact, cortical bone in contact with the implant surface without any gaps or connective tissue formation was observed.

CONCLUSIONS

It was concluded that immediately loaded, splinted implants can be osseointegrated with a similar hard and soft tissue peri-implant response as delayed-loaded implants in the posterior mandible.

Cemento-ossifying fibroma with mandibular fracture. Case report in a young patient

The cemento-ossifying fibroma is classified as an osteogenic neoplasm of the jaws. It commonly presents as a progressively growing lesion that can attain an enormous size with resultant deformity if left untreated. A case of a large cemento-ossifying fibroma involving the left mandible is described in a 15 year old male patient. The clinical, radiographic and histological features as well as surgical findings are presented. The treatment of choice of this lesion is also emphasized. Two years after surgery, there was no evidence of recurrence and the transosseous wire used to immobilize the fracture was found to be completely buried in the jaw bone.

Preoperative prediction of intra and postoperative red blood cell transfusion in surgical patients

Anaesthetists were asked to predict the need for intra and postoperative red blood cell transfusion in 1706 patients before surgery. Each prediction was made using only the individual patient's medical history and physical examination, the results of routine preoperative laboratory investigations, and knowledge of the proposed surgical procedure. Only 159 patients (9.3%) received red blood cell transfusion. The sensitivity and specificity of this preoperative prediction were 85.5% and 96.6% respectively, whereas the positive and negative predictive values were 72.3% and 98.5% respectively. Using a stepwise logistic regression model, preoperative haemoglobin concentration, Surgical Table of the procedure, and age of patients were found to significantly determine the need for intra and postoperative red blood cell transfusion. It is recommended that type and screen should replace group and crossmatch procedures in surgical patients where no intra and postoperative red blood cell transfusion is predicted as necessary.