The pre-implant surgical stage consisted of extraction with site preservation. The mandible was anesthetized and teeth Nos. 23, 25, 26, 28, and 30 were removed. The sockets were debrided with a double-ended curette and grafted with a mineralized irradiated cancellous allograft (Puros®, Zimmer Dental, www.zimmerdental.com) and contained with a d-polytetrafluoroethylene (Cytoplast™, Osteogenics Biomedical, www.osteogenics.com) barrier. The extractions of the maxillary arch consisted of teeth Nos. 1, 4, 6, 12, and 13, and the procedure and grafting materials employed in the maxilla mimicked the mandibular arch (Figure 4). Maxillary and mandibular removable partial dentures (RPDs) were placed, occlusion adjusted, and polished (Figure 5).
The maxillary implant surgical procedure was initiated 3 months after the extractions and socket grafting. The patient was prepped, draped, and asked to rinse with a 0.12% chlorhexidine mouth rinse for 30 seconds. The blood separation process to develop platelet-rich plasma was initiated. The patient was anesthetized, and a midcrestal incision with a 15c blade was made and a full mucoperiosteal flap reflected with a periosteal elevator. A surgical guide was placed and four osteotomy “dimples” were made with a surgical long shank No. 4 round bur. The implant surgical protocol drill sequence was 1.3, 2.0, 2.5, and 3.1 mm to a depth of 12 mm for the future 3.8-mm diameter implants. The 4.8-mm diameter implant required two additional drills, 3.8 and 4.1 mm, to complete the osteotomy. Three 3.8-mm x 12-mm RBC Tapered Laser-Lok (BioHorizons, www.biohorizons.com) implants were placed at the crest using a fixture mount and a 2.5-mm hex driver. The cover screw was secured to the fixture via a 1.25-mm hex tool. The mucoperiosteal flap was closed using 4.0 vicryl sutures in a horizontal mattress manner.
The mandibular implant surgery was initiated 3 months after the maxillary implants were placed. The preparation and anesthesia of the patient were similar to the maxillary implant surgery. A full mucoperiosteal flap was established with a 15c blade penetrating midcrestally and reflected with a periosteal elevator. A surgical template was placed to aid in the mesial-distal location of the future implant sites (Figure 6). The partial osteotomies were prepared with a 1.1-mm drill to a depth of 6 mm. The four 2-mm x 13-mm O-ball collared MDIs (MDI Mini Dental Implants, 3M Oral Care, www.3mespe.com/implants) were auto-advanced with a finger driver, thumb wrench, and ratchet to final position (Figure 7). The transitional RPD was relieved where the transgingival aspect of the o-ball was located and the occlusion was adjusted.
Second stage surgery for the maxillary arch consisted of the exposure of the conventional implants and extraction of all remaining teeth. This procedure was initiated 6 months post implant placement. Three 3.8-mm x 5-mm and one 4.8-mm x 5-mm titanium healing collars were placed during the surgical uncovering procedure. In addition, teeth Nos. 3, 11, 14, 19, 22, 27, and 30 were extracted (Figure 8). The transitional RPDs were modified to incorporate additional prosthetic teeth and relined with a soft temporary material. The soft tissues healed for 6 weeks prior to prosthetic reconstruction.
The prosthetic reconstruction stage was unique to the specific type of implant design utilized in the treatment plan. The primary objective of the impression stage was to capture the position and angulation of the implants. The maxillary arch employed an open-tray impression technique to capture an abutment level impression (Imprint™ 3 VPS Impression Material, 3M Oral Care) (Figure 9). The mandibular MDIs were impressed after placing “red” transfers onto the o-ball aspect of the implant (Figure 10). A polyvinylsiloxane impression material (Imprint 3) was utilized within a border molded custom tray for both arches.