OSSEOINTEGRATION OF BRANEMARK FIXTURES USING A SINGLE-STEP OPERATING TECHNIQUE - A PRELIMINARY PROSPECTIVE ONE-YEAR STUDY IN THE EDENTULOUS MANDIBLE

The aim of the present prospective clinical study was to analyze the feasibility of inserting Branemark fixtures according to a one-stage procedure including transmucosal healing and to subsequently evaluate the predictability of osseointegration as well as the potential of such implants for stabilizing complete overdentures in the edentulous mandible. Five patients (2 women, 3 men), completely edentulous in the mandible and with a mean age of 60 years, volunteered for this study. Two fixtures of various length (10-20 mm) and 3.75 mm in diameter were inserted in the lower canine regions. A standard surgical procedure including a mid-crestal incision was used. After the placement of the fixtures, healing abutments, which are normally used during second-stage surgery, were inserted instead of the usual cover screws. Three months after implant placement a clinical and radiographic examination was performed to confirm the presence or absence of osseointegration of the fixtures prior to exchanging the healing abutments with the spherical attachments. Finally, different clinical (Plaque Index, Bleeding Index, probing depth, Periotest(R) mobility) and radiographic (bone-loss, peri-implant radiolucency) parameters were recorded 9 months after loading of the fixtures by means of a complete mandibular overdenture, retained by two ball attachments in the canine regions. All fixtures were perfectly stable (mean Periotest values of -2) and presented favorable peri-mplant soft tissue conditions, and no patient was complaining about any particular symptom. As far as retention and stability of their implant supported overdenture was concerned, the participants without exception considered the therapeutic result as being perfectly adequate. The evaluation of the radiographic analysis showed a similar initial bone loss rate as reported in the literature for a submerged surgical procedure. Therefore, within the specific limits of this study, it may be concluded that Branemark fixtures can be inserted using a single-step surgical protocol predictably leading to successful osseointegration and subsequently;provide similar peri-implant results as reported for the traditional two stage technique. However, a longer period of observation as well as a more significant number of cases will be necessary to confirm these promising preliminary data.