Root Membrane Technique-An Insight

There are different treatment options in modern dentistry for the replacement of lost dentition. Of these the most upcoming and acceptable treatment option is Dental implants. The common problem usually with immediate implant placement in the anterior region is the post-operative soft tissue contour as a part of the bone modelling during healing. Hurzeler et al in 2010 introduced a new technique called the “socket shield technique”. This technique has been used as an alternative treatment modality for immediate implant placement in the aesthetic zone.This review articles provides a detailed information regarding the clinical concept of Root membrane technique.


Introduction
One of the main challenges in dentistry is replacing the missing tooth or teeth restoring its function and aesthetics. There are different treatment options in modern dentistry for the replacement of lost teeth. Of these the most upcoming and acceptable treatment option is Dental implants. Dental implants, made of titanium can be used for the replacement of both the anterior as well as the posterior dentition that will ultimately restore the aesthetics and function of the missing teeth. These implants can be placed immediately after extraction of the teeth. The common problem usually associated with immediate implant placement in the anterior region is the post-operative soft tissue contour loss as a part of the bone modelling during healing.
This may indirectly affect the aesthetics and long-term function of the implant.
To overcome these problems, Hurzeler et al in 2010 introduced a new technique called the "Socket shield technique". This technique has been used as an alternative treatment modality for immediate implant placement in the aesthetic zone. It is also called as Root membrane technique as it utilizes the buccal two third of the tooth root which is kept inside the socket.
The intentional retention of the root fragment serves to preserve or maintain the normal soft tissue contour throughout the entire period of implant function.

Root membrane Technique
Following adequate anaesthesia of the site for immediate implant placement, the crown portion of the tooth is removed at the gingival level with utmost care not to damage the gingiva. Under copious irrigation, with the use of a long shank root resection surgical bur, the tooth root is carefully sectioned mesiodistally and longitudinally midway through the root with the canal as a reference point, such that labial and the palatal halves are separated from each other entirely from the coronal to apical aspect. Followed by this separation, a microperiotome is used to displace the palatal halves and retrieved using microforceps (1). After this, the socket should be carefully evaluated to make sure that there is no mobility of the remaining buccal two third of the root. This prepared tooth root shields the buccal wall of the socket and prevents the recession of the tissues buccofacial to an immediately placed implant(2).

Classification of Root membrane Technique
Depending on the position of the shield in the socket, root membrane technique can be classified as follows: (3

Clinical concept
The most physiologic approach to prevent alveolar ridge resorption is to naturally preserve the root if possible (4). A very minor amount of inflammatory alteration or bone growth is observed around the root submerged for alveolar bone preservation (5). The root membrane concept intends to minimize volumetric alteration at the implant site by evenly maintaining the contour of soft and hard tissue around the immediately placed implant, throughout its function (6,7).
Normally, tooth extraction results in loss of periodontal ligament along with its vascular supply which provides nutrition to the buccal bone (8,9,10,11,12). In the absence of this nourishment, there will be physiologic bone resorption of the buccal bone leading to contraction of the soft tissues ultimately results in aesthetic dilemma (13, 14, 15, 16). Studies put forward various techniques such as GBR, soft tissue grafting, socket preservation and also the use of various graft materials to limit this physiologic resorption (17, 18, 19, 20, 21). The clinical concept or the rationale behind the root membrane technique is that, maintenance of the buccal portion of the root helps in maintaining the PDL and the associated vessels which may in turn prevent the physiologic resorption of the buccal bone, preserving the esthetics of the ridge (22, 23). Also, the flapless approach allows for maintenance of vascular supply from the supraperiosteal artery "root membrane technique" because the attached PDL on the is retained root fragment is the prime reason why blood supply and nutrition is maintained and thus ridge resorption is prevented. (24) Indications (