Immediate Implant Placement Following Tooth Extraction And Provisionalization
In The Aesthetic Zone: A Case Presentation
Alan M. Meltzer, DMD, MScD
Shares A Case Using
NanoTite™ Tapered Implants
Patients today demand aesthetic replacements for teeth with hopeless prognoses. They also demand shorter treatment times with minimal personal inconvenience. Replacement of hopeless teeth due to extensive caries with immediate implant placement and immediate provisional restorations represents a protocol to satisfy these patient requirements. Implant designs with tapered configurations and enhanced surfaces, coupled with restorative flexibility using inexpensive, provisional abutments, provide clinicians with the ability to perform these procedures at reasonable costs with predictable outcomes. Implants such as the NanoTite Certain® Tapered Implant closely approximate the shape of natural tooth roots. This implant has threads that widen laterally while extending to the apical end. This provides improved stability throughout the length of the implant while maximizing Bone-to-Implant Contact (BIC) between the implant and osteotomy. The thread angle, along with the depth and pitch, produce an anchoring “bite in bone” effect.
The following Clinical Case Presentation demonstrates the combined techniques of tooth extraction with immediate implant placement of NanoTite Certain Tapered Implants and immediate provisionalization with PreFormance Provisional Components.
A 39-year-old male patient was referred for an implant consultation. Clinical and radiographic examinations revealed extensive caries (teeth Nos. 6, 7, 10 and 11) under a previously placed splinted fixed prosthesis (Figures 1 and 2). Teeth Nos. 8 and 9 presented with unfavorable crown-to-root ratios, mobility in the range of 2+ to 3 and palatal caries requiring crown lengthening and endodontic therapy. The treatment plan accepted by the patient included tooth extractions, simultaneous implant placement, grafting and immediate provisionalization. Prior to surgery, impressions were made for fabrication of a laboratory processed provisional fixed partial denture for teeth Nos. 6-11.
Due to the extensive caries in tooth sites Nos. 6, 7, 10 and 11, the splinted crowns were sectioned and removed first (Figure 3). Teeth Nos. 6, 7, 8, 9, 10 and 11 were carefully extracted using periotomes (Figure 4) and the sockets were debrided with hand and rotary instruments (Figure 5). Using copious irrigation, preparation of the implant osteotomies began in the cuspid site, tooth No. 6, with an ACT® Pointed Starter Drill. The pointed shape on the drill allowed the osteotomy to be properly positioned into the extraction socket, directed along the palatal wall for proper alignment of the implant. Preparation of the osteotomy continued with the 2mm diameter twist drill used to the full predetermined depth of the planned implant. This allowed for development of optimal contours and thicknesses for the periimplant soft tissues. A direction indicator was placed into the partially prepared osteotomy to determine proper 3-D positioning of the implant following classic immediate implant placement criteria. Initial preparation of the osteotomies for tooth sites Nos. 8, 9 and 11 proceeded in the same manner.
Next, the corresponding length 3.25mm diameter Quad Shaping Drill (QSD) for placement of NanoTite Certain Tapered Implants was used to continue the preparation of the osteotomies to the full predetermined depths. The 3-D accuracy of the osteotomies was then determined using the corresponding sized tapered implant depth and direction indicator. Preparation of the osteotomies continued with 4mm and 5mm diameter QSDs followed by placement of the corresponding depth and direction indicator in each site. To ensure complete seating of the implants and to maximize BIC, the osteotomies were rinsed with saline and suctioned. Accuracy of the prepared osteotomies was confirmed with placement of the 5mm diameter depth and direction indicator. A visual note was made of the precise position of the depth and direction indicator. NanoTite Certain Tapered Implants (5mm diameter) were placed at 25 revolutions per minute (rpm) and 45Ncm of torque without irrigation into the prepared osteotomies of tooth sites Nos. 6, 8, 9 and 11. Due to aesthetic considerations and space limitations, implants were not placed in the maxillary lateral incisor sites. Final seating of the implants into the osteotomies was accomplished with a hand ratchet until the restorative seating surface of each implant was at the same level as was visualized with the final diameter depth and direction indicator (Figure 6). The hand ratchet was used to maximize primary implant stability and initial BIC, as well as to follow the vertical position dictated by the depth and direction indicator(s). Insertion torque values were recorded in excess of 100Ncm as measured with a custom torque indicator. Xenograft bone grafts were placed in tooth sites Nos. 7 and 10 to fill the extraction sites and in tooth sites Nos. 6, 8, 9 and 11 to fill the voids between the facial surfaces of the implants and the palatal surfaces of the intact facial plates. Implant Stability Quotient (ISQ) readings in excess of 75 confirmed high initial stability of the implants. This more than fulfilled the guidelines for immediate provisionalization of the implants.
Certain® Non-Hexed PreFormance® Temporary Cylinders with 4.1mm restorative seating surfaces were selected for use as interim abutments. The abutments were seated into the internal interfaces of the implants and secured with abutment screws. These abutments fulfilled the requirements for Platform Switching. The prefabricated laboratory processed screw-retained provisional fixed partial denture (FPD) with occlusal rests on the adjacent teeth was hollowed out in the approximate locations of the implants. It was tried in intraorally and positioned onto the occlusal surfaces of the adjacent teeth to stabilize the prosthesis during relining. This replicated the position of the provisional FPD that was developed in the laboratory. Passive fit of the provisional FPD over the prepared temporary cylinders was verified. The screw access openings were blocked out with hollow sprue cylinders to prevent acrylic resin from flowing into the screw access openings (Figure 7).
The PreFormance Temporary Cylinders were luted to the laboratory processed provisional FPD using a brushed bead-on technique. Once the acrylic resin polymerized, the provisional restoration was removed (Figure 8).
The occlusal rests were removed and the voids around the PreFormance Temporary Cylinders were filled with acrylic resin and overbulked at the same time to provide ample restorative material necessary for developing optimal emergence profiles.
The provisional restoration was then trimmed and polished (Figure 9). The FPD was reseated intraorally and secured with abutment screws tightened to 20Ncm of torque. Centric and eccentric occlusal contacts were eliminated, following the guidelines for immediate non-occlusal loading. The patient was provided with appropriate post-operative instructions. Post insertion radiographs were taken.
The patient returned for evaluations over the next eight weeks post implant placement and insertion of the provisional prosthesis. Healing was uneventful (Figure 10).
Twelve weeks post extraction, immediate implant placement and provisionalization, the patient was seen for impressions and fabrication of the definitive prosthesis. Implant level impressions were made to develop the master casts. A definitive FPD supported by GingiHue® Posts (tooth sites Nos. 8 and 9) and Non-Hexed UCLA Abutments (tooth sites Nos. 6 and 11) was fabricated for a combined cement and screw-retained prosthesis. The patient returned for insertion of the abutments and the definitive FPD (Figure 11). Periapical radiographs were taken and confirmed high levels of interproximal bone adjacent to the implants (Figure 12).
Laboratory Colleague: Yacov Dvorkin, Colonial Dental Laboratory, West Berlin, NJ.
Dr. Meltzer (USA) received his dental degree from the University of Pennsylvania and his Masters in Periodontics and Oral Medicine from Boston University, School of Graduate Dentistry. He is a Diplomate of the American Board of Periodontology and a Fellow of the Academy of Osseointegration, where he serves on its Research and Education Committees. Dr. Meltzer maintains a private practice in Voorhees, New Jersey.