Australasian Dentist Issue 92

CATEGORY 74 AUSTRALASIAN DENTIST D ental implants in theaesthetic zonecan be considered a complex technique taking into account many factors. Surgical, host and aesthetic factors can turn these cases into potentially terrible outcomes for patients when planning is not done correctly from the outset. The aesthetic zone poses a challenge predominantly due to resorption of the buccal bundle bone upon removal of existing teeth. The resulting bone resorption and soft tissue shrinkage and recession that occurs can mean multiple surgical procedures to overcome which can be a problem for patients as well as clinicians. One technique posed to overcome these challenges is Partial Extraction Therapy. Other terms used to describe this technique include the root membrane technique. In this procedure a thin labial portion of the existing tooth is maintained and bevelled to maintain the buccal bundle bone. The palatal portion and main body of the root is carefully sectioned and removed to allow for either immediate implant placement or socket preservation as per normal criteria. The technique shows strong results in the literature with complication rates being very low and non-significant. The drawback is the procedure canbe challenging to adopt initially and technique sensitive. Proper armamentarium should be used to conduct this procedure to minimise complications such as luxation and movement of the buccal portion of the root. The following case shows a healthy 50 year old female with an upper left central incisor number 21 with existing post core crown prosthetic work. Clinically and radiographically the tooth exhibited a history of failing prosthetic work and multiple attempts at recementing the existing post core and crown. After going through the options and considering the lack of ferrule under the crown, the patient opted for tooth removal, and replacement with a dental implant with the request of minimising surgical procedures where possible. Like all dental implant cases proper planning is required from the beginning. This included full photography, intra oral digital scanning using Trios, as well as CBCT imaging. 3Shape planning allowed the fabrication Partial Extraction Therapy in the aesthetic zone By Dr Johan Weemaes of a surgical guide as well as a PMMA provisional crown to be used on the day of surgery if primary stability was achieved upon implant placement. A temporary removable retainer appliance was created as well for use if the temporary crown could not be used. On theday of surgery thepatient is given 2g of amoxicillin antibiotic prophylaxis. Full sterile draping and set up is done for the procedure, and the patient uses Savacol mouth rinse for one minute before surgery. After Local Anaesthesia the crown is removed, and a high speed diamond drill is taken to the apex of the tooth root using the existing root canal as a guide. The drills used are an extended length to allow visualisation whilst performing this. Different kits are available to perform PET. The drill is then taken mesial to distal to section the tooth root. Carefully periotomes are used to luxate and remove the palatal portion. Round diamond drills are used to lower the buccal root portion down to the level of the bone, whilst protecting the gingiva from trauma using small instruments. The buccal shield is also bevelled to allow for prosthetic space of the temporary appliance and the transition zone from the implant collar to the gingival margin. The surgical guide from DIO allowed placement of a UFII 3.8 x 11.5mm Fixture into the apical bone with 40 Ncm of torque. The hex was aligned with the surgical guide to correspond to the direction planned, so that the temporary prosthesis would engage correctly in orientation. Smart peg placement and ISQ value reading showed a value of 78 which allowed us to confirm primary stability. The gap between root shield and implant was grafted with a mix of autogenous scrapings from the guided surgical drills as well as xenograft particulate material (Bio-oss). The temporary crown was checked for seating LINICAL Figure 1 Initial Presentation Figure 2 Smile Line Figure 3 Resting lip line Figure 4 Side photograph Figure 5 Side photograph Figure 6 Intra oral scanning Dr Johan Weemaes