Conditions: Missing Tooth
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 32
Healthy volunteers: yes

Brief summary:
An important result of healing after tooth extraction is a reduction in dimensions of the remaining bone at that site. This reduction of bone volume precludes successful restoration of the space using a dental implant. Bone augmentation has shown promise in clinical reports to reduce this loss of bone volume, thus allowing implant placement and restoration. The purpose of this study is to evaluate the clinical and radiographic outcomes of guided bone regeneration around dental implants placed in fresh extraction sockets.

Detailed description:
Aim: The purpose of this clinical study is to investigate the effect of a non-resorbable polytetrafluoroethylene (PTFE) membrane on immediate implant placement in the esthetic zone.

Material and Methods: Systemically healthy subjects presenting with a hopeless tooth in the maxillary premolar or anterior region will be recruited in the study. Following a minimally traumatic tooth extraction, subjects will be randomly distributed into one of two treatment groups, a Membrane (Test) or a No Membrane (Control) group. Both groups will receive immediate placement of an implant along with placement of a bone graft material to fill the spaces around the implant. Sites in the test group will receive a non-resorbable PTFE membrane over the socket, whereas those in the control group will receive a collagen dressing over the socket. At sites in the test group, the membrane will be removed at 4 weeks. A second stage surgery and placement of a provisional restoration will be carried out 4 months after implant placement. Final restorations will be placed 3 months after placement of the provisional restoration. Clinical and radiographic measurements will be performed at baseline, implant placement, placement of provisional and final restorations and at the 5-month recall visit.

Arms:
arm 1: Test (membrane): Extraction and immediate implant placement will be performed. The gaps between the implant and socket walls will be filled with a bone graft material. Sites in the test group will receive a high-density PTFE (d-PTFE) membrane over the socket. arm 2: Control (collagen plug): Extraction and immediate implant placement will be performed. The gaps between the implant and socket walls will be filled with a bone graft material. Sites in the control group will receive a collagen wound dressing over the socket.

Interventions: intervention 1: Minimally Traumatic Tooth Extraction intervention 2: Immediate Implant Placement intervention 3: Bone Graft Placement intervention 4: Membrane placement intervention 5: Collagen plug placement intervention 6: Medications
Intervention descriptions: intervention 1: The surgeon will perform a minimally traumatic tooth extraction in the following fashion. Intrasulcular incisions will be performed with at 15-C scalpel around the tooth to be extracted.

A periotome will then be introduced into the periodontal ligament space in order to sever the subcrestal attachment and expand the periodontal ligament space. Elevators will be used to initiate luxation of teeth. After significant mobility has been achieved through elevation, forceps will be used only to deliver the tooth. Finally, the socket will be curetted to remove all granulomatous tissue and irrigated with sterile isotonic saline solution. intervention 2: A threaded titanium alloy implant with an internal hex connection and a Resorbable Blast Texturing (RBT) surface (Tapered Internal® Implant System, Biohorizons, Inc., Birmingham, AL, USA) will be placed using a surgical guide. Implant diameter of 3.8mm with lengths of either 12 or 15mm will be used. Implants will be placed approximately 3-4mm below the free gingival margin or 2-3mm below the cemento-enamel junction of adjacent teeth. intervention 3: Circumferential defects or dehiscences around the immediately placed implant will be grafted. enCore™ Combination Allograft (Osteogenics Biomedical, Lubbock, Texas, USA) will be used as the bone graft material. intervention 4: A non absorbable d-PTFE membrane (Cytoplast® TXT-200, Osteogenics Biomedical, Lubbock, Texas, USA) will be trimmed to an appropriate size and shape to completely cover the implant site, and extend about 3-5mm beyond on the facial aspect. The membrane will be tucked under the sub-periosteal flap. Care will be taken to ensure that the membrane is resting on bone all around the socket margins. The membrane will be kept a minimum of 1.5mm from the adjacent tooth roots in the interdental area. intervention 5: A bio-absorbable collagen wound dressing (CollaPlug®, Zimmer Dental, Carlsbad, CA, USA) will be trimmed to the appropriate size, so as to cover the socket intervention 6: Patients will be given amoxicillin 500mg 2 days prior to the surgery and will then continue for every 8 hours for 10 days. Patients will also take Ibuprofen 600mg every 6 hours for the first 3 days following the surgery, and then as needed for pain. Patients will also receive a prescription for Vicodin as needed for pain, every 4 to 6 hours

Protocol document: