Utilizing Digital Treatment Planning and Guided Surgery in Conjunction with Narrow-Body Implants

PAGE 1 OF 7

The patient in this case, a 64-year-old white female, had been edentulous for more than 25 years. Although her maxillary conventional complete denture was retentive and provided lip support for esthetics, her mandibular conventional complete denture was never completely stable and dramatically diminished her perceived quality of life. Although well made, the mandibular conventional denture provided her with decreased chewing function. As the years progressed, the denture became less tolerable due to the instability of the appliance, and the patient's interest in dental implant reconstruction became more apparent. There were no apparent medical complications for this procedure. Oral and radiographic examination revealed good vertical height of the mandibular ridge.

CT diagnosis allowed us to visualize the patient's available bone in three dimensions and to virtually place the implants prior to any surgical intervention. CT scanning has fast become an important tool in the diagnosis and treatment of dental implant position and placement.

PAGE 2 OF 7

When considering dental implant placement in the mandibular arch, compromised conditions can result in poor positioning or angulation, which will make fabrication of the final prosthesis difficult. The main objective in dental implant placement is improving stability of the denture and providing retention, thus increasing chewing efficiency. Over time, the implants will minimize further bone loss.

A patient's understanding of the benefits of dental implant therapy is certainly a motivator to patient acceptance. Wearing a removable appliance can be difficult to tolerate physically and emotionally. Creating an appliance with improved retention and stability helps alleviate functional and psychological concerns.

The 3.0 mm I-Mini® IOT/O-ball dental implant (OCO Biomedical; Albuquerque, N.M.) is proving to be an outstanding small-diameter implant for immediate overdenture stabilization. It is a one-piece implant designed with a ball that serves as the male component to the long-used O-ring system. The design is intended for immediate-load and immediate-function capability.

PAGE 3 OF 7

The surgical technique used to place the 3.0 mm I-Mini IOT/O-ball implants was simple and precise. Chairtime was reduced dramatically following diagnosis using CT scanning software and virtual placement of the dental implants using Blue Sky Plan® treatment planning software (Blue Sky Bio; Grayslake, Ill.).

The technology behind digital treatment planning and guided surgery is based on long-used planning algorithms. CT scans and 3-D software improve predictability and safety for the clinician, especially in areas of anatomic concern, such as a thin mandible, as demonstrated in this case. The surgery is driven by the demands of the final esthetic and functional prosthetics. Final tooth position is established prior to any surgical intervention to ensure compatibility between the surgical placement and the clinician's and the patient's expectations of the final result.

CT planning and placement systems provide an increased level of comfort and safety for patients by reducing surgical and restorative chairtime. This is accomplished by utilizing an accurate three-dimensional plan prior to surgical placement of the implants.3 There are several advantages to doing this. The case is more easily presented to the patient. There is reduced surgical chairtime and reduced prosthetic chairtime because the implants are properly positioned.

PAGE 4 OF 7

Prior to the CT scan, the dental lab fabricated a scan appliance, which aids in visualizing the optimal prosthetic outcome. The teeth are then properly positioned in wax, or the patient's existing denture can be duplicated if it is well fitting. Either way, a hard appliance is processed to illustrate what the case will look like when finished, before it is even started.

In this particular case, the patient's existing conventional complete denture was duplicated. All appropriate dental anatomy was included. The scan appliance was placed into the mouth during the CT scan.4 Doing this enables the clinician to see the ideal position of the teeth in a 3-D model. The entire 3-D image is analyzed, and the implant planning and simulation of implant placement completed using the computer. The surgical placement of the implants can be done in a conventional manner using the newly created surgical guide to help direct the drills in the ideal direction. Often this can become a flapless procedure. The implants are then simply placed in the desired depth and direction using the computer software and the surgical guide.5

In this case, a surgical guide based on the virtual plan and fabricated by Glidewell Laboratories was utilized. It consisted of 1.8 mm sleeves, which allowed for directional determination of the dental implants to be placed. This surgical guide was fabricated using the information created by the CT scanning software. The guide was used to determine correct directional placement of the implants in the patient's symphysis area. Because bone and soft tissue were compensated for in the fabrication of the surgical guide, no reflection or flap was needed in the placement of the implants.

PAGE 5 OF 7

Figure 1 shows the preoperative bone morphology in a two-dimensional radiograph. Clinically, there appears to be a thin mandibular ridge (Fig. 2). However, the 3-D view reveals a relatively short, wide ridge with a thick cortical plate (Fig. 3). Utilizing the patient's existing denture as a scan appliance, we were able to plan the case from a surgical and a prosthetic perspective. Four 3.0 mm I-Mini IOT/O-ball implants were planned in the symphysis. The implants were angled slightly to the labial to maximize the length, thus establishing bicortical stabilization and locating the O-ball head of the implants under the anterior teeth of the denture.

The surgical guide with directional sleeves for the pilot drill was fabricated based on the CT scan of the patient's existing, well-fitting conventional complete denture (Fig. 4, Fig. 5). A small-diameter pilot drill was used through the sleeves of the surgical guide to create proper angulation and position of the four small-diameter implants (Fig. 6a, Fig. 6b). Perforations were made through the soft tissue and ridge crest, allowing for directional placement of the implants (Fig. 7). The directional guide was then removed and a 1.8 mm drill used to depth as determined by analysis of the CT planning software (Fig. 8). The directional openings were used to correctly angle the drills to the predetermined depths – 14 mm for the #23 and #25 implants, and 12 mm for the #22 and #27 implants. A radiograph was taken to ensure proper depth (Fig. 9). A 2.4 mm drill was then used to the predetermined depth to create the osteotomy site for the 3.0 mm mini implant (Fig. 10). Because we were using a self-tapping implant, there was no need to use a thread former. The final drill used to form the osteotomy was side-cutting only. The pilot drill alone determined the depth of the implant placement. There were no intermediate-sized drills used in this technique.

PAGE 6 OF 7

Figure 14 and Figure 15 show the first implant in position intraorally as well as radiographically. Subsequent implants were placed using the same protocol (Fig. 16, Fig. 17). Figure 18 and Figure 19 show the four implants ideally placed in the mandibular symphysis and the final radiograph. Note there is little bleeding, as this was a flapless procedure. Also note that the lingual plate is more coronally positioned than the labial plate, and the implants are positioned in the center of the ridge.

Next, the patient's existing mandibular complete denture was relieved and a chairside soft reline material was placed to stabilize the denture (Fig. 20). The patient experienced immediate improvement of the retention and stability of her mandibular denture (Fig. 21). She also experienced minimal discomfort following placement of the conditioning material. After integration progresses, a new mandibular implant-retained overdenture with O-rings will be used to create retention, stability and an increased quality of life for our patient. Figure 22a and Figure 22b show the postoperative CT scan as compared to the virtual plan.

The OCO Biomedical 3.0 mm I-Mini one-piece overdenture implant system allowed us to strategically place predictable implants to improve the patient's functional ability.

PAGE 7 OF 7

This case demonstrates just one of the innovative techniques available to clinicians and our patients. CT scans and digital planning software make the surgical placement of dental implants simple and effective. Anatomical anomalies are virtually determined prior to any surgical intervention. Using this system, implants can be ideally placed and maintenance is routine.