Comparison of bone dimensional changes in immediate implant placement in mandibular premolars and/or molar sites with a horizontal gap more than 2 millimeters with or without graft: A Randomized clinical trial

The purpose of this study is to compare the clinical and radiographic effects of different types of bone grafts on alveolar bone dimensions after immediate implant placement.

This double-blind parallel randomized clinical trial in phase 2-3 includes a total of 40 patients who have been randomly assigned to 4 groups.

The present study is a parallel randomized clinical trial with four arms. The study will be conducted in the fall of 1403 at the Faculty of Dentistry in Isfahan

The inclusion criteria for this study include age over 18 years, good oral hygiene, the presence of premolar or mandibular molar with hopeless prognosis due to severe caries or irreparable fracture

Patients in the first group receive one immediate implant without graft material and without membrane. Patients in the second group receive one immediate implant with allograft and membrane. Patients in the third group receive one immediate implant with xenograft and membrane. The patients of the fourth group receive immediate implant with the equal ratio of combination of xenograft, allograft and membrane

To evaluate the vertical changes, the vertical distance between the implant shoulder and the crest of the buccal bone surface is measured along the longitudinal axis of the implant. If the bone is higher than the shoulder implant level, this situation is considered positive, but if the more apical bone is If the shoulder implant is placed, this situation is negative and they are evaluated in different groups. If there is a negative situation and the presence of bone resorption, a small reconstruction (Mini GBR) should be performed using autogenous bone in the vicinity of the resorption area, and the patient should be reevaluated 3 months later.

After evaluating pre-surgery CBCTs, 40 patients who need to extract mandibular premolar and molar teeth and simultaneously place implants in these areas are included in the study. These patients will be assigned to one of 4 groups in a random block format in the form of 5 blocks of eight in which two people from each intervention will be present in each block. The way to choose the blocks is also based on the fact that the number of possible states of forming 8 blocks, which is a total of 2520 states, is determined by the Random Allocation Software 2.0 software, and five times out of these possible states, the block is selected randomly. In total, by choosing these five modes of blocks of 8, 40 patients will be assigned to 4 intervention groups based on the order of placement in the blocks and the selection of the blocks.

This study is done in a double-blind manner because the patient does not know which group he is placed in and the evaluator is also blinded, but it will be very difficult to blind the surgeon because the types of these transplant materials are recognizable from each other.