Evaluation of Papilla Index Around Immediate Mandibular Molar Implants Using Customized Healing Abutment Versus Submerged Healing

Overview

The original implant treatment protocol recommended that the implant should be placed in a fully healed site and covered with mucosa after placement to ensure osseointegration. The reason was to protect the implant site from bacterial contamination and to avoid loading of the implant. After that, a second stage surgical procedure had to be performed to expose the implant to connect the abutment. However, it was shown that a one stage or non-submerged (NS) approach can lead to successful and predictable outcomes. Customized healing abutments can be used in the non-submerged protocol, protecting and containing the bone substitute during healing, preserving the alveolar contour, preventing food impaction, and eliminating the need for a second stage surgery and. By means of this technique, critical and subcritical contours can be projected speeding up the peri-implant soft tissue conditioning phase in order to achieve final natural-like restorations. This randomized controlled trial will compare the clinical and radiographic hard and soft tissue changes using chairside customized healing abutment versus submerged healing following immediate implant placement in mandibular molars through measuring the horizontal ridge changes by CBCT , the crestal bone loss by a standardized digital x-ray and the soft tissue changes by the pink esthetic score (PES).

Immediate implant placement in extraction sockets was used to (i) reduce the number of surgical procedures (ii) preserve the dimensions of the alveolar ridge and (iii) reduce the interval between the removal of the tooth and the insertion of the implant supported restoration. Flapless extraction is a technique aimed towards leaving the periosteum undisturbed by extracting the tooth with minimal trauma using periotomes without flap reflection. They also found less crestal bone loss around immediate implants placed in flapless extraction sockets in compared to implants placed by elevating a flap, due to greater blood supply and less postoperative swelling and pain. Submerged healing and absence of loading was proposed during the early stage of osseointegration. Such a two-stage approach, based on a period of submerged healing aimed at optimizing the process of new bone formation and remodeling that follows implant placement is considered the gold standard procedure. It requires a second surgery to connect the abutment. This second surgical procedure is generally a minor one; thus, it is not particularly uncomfortable for the patient and offers the possibility to perform soft tissue management procedures around healed implants which may result in a better long-term prognosis. On the other hand, the desire to provide faster and less invasive treatment to patients, as well as to avoid postponing implant load and prosthesis delivery, has led to one-stage surgery (non-submerged healing). In this approach the implant and the healing abutment are placed in a single procedure so it remains exposed in the oral cavity during the osseointegration period. The provisional restoration or a custom abutment can act as a "prosthetic socket-sealing" to protect, contain and maintain the blood clot and bone-graft material during the healing phase of treatment. The aim of this randomized clinical trial is to evaluate the clinical and radiographic hard and soft tissue changes using chairside customized healing abutment versus submerged healing following immediate implant placement in mandibular molars.