Editorial Type:
Article Category: Other
 | 
Online Publication Date: 01 Dec 2014

Why Guided When Freehand Is Easier, Quicker, and Less Costly?

DDS, MSD,
DDS, PhD, and
DDS, MMSc
Page Range: 670 – 678
DOI: 10.1563/aaid-joi-D-14-00231
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Computer-assisted implant planning and subsequent production of a surgical template based on this plan has gained attention because it provides restoratively driven esthetics, patient comfort, satisfaction, and the option of flapless surgery and immediate restoration. However, it adds expense and requires more time. Another significant but not so apparent advantage may be improved survival and success over freehand techniques in types III and IV bone. This retrospective analysis was undertaken to examine that possibility. It reports 1-year outcome for 80 implants in 27 consecutively presenting patients treated over a 7-year period using computer-assisted techniques across all bone qualities in commonly encountered treatment indications in private practice. Implants were placed to support single teeth, small bridges, and complete arch restorations in exposed or immediately restored applications, based on primary stability as determined by insertion torque, resonance frequency analysis, and Periotest. For the 80 implants supporting 35 restorations, the median observation period is 2.66 years; 73 implants supporting prostheses in 22 patients had readable radiographs at 1 year. There was a 1-year overall implant survival and a success rate of 100%. Radiographic analysis demonstrated the change in bone level from the platform at 1-year is less than 2 mm. Intra-operative median measurements of primary stability were insertion torque, 40 Ncm; resonance frequency, 76 ISQ; and Periotest, −3. All intra-operative measurements were consistent for acceptable primary stability regardless of bone density. Restoratively driven diagnosis and precision planning and initial fit were possible with computer-assisted techniques resulting in the achievement of high primary stability, even in areas of less dense bone. The ability to plan implant position, drill sequence, and implant design on the basis of predetermined bone density gives the practitioner enhanced pretreatment information which can lead to improved outcome.

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  <sc>Figures 1–3.</sc>
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Figures 1–3.

Figure 1. Radiographic template incorporating teeth to be replaced placed intra-orally for the CT scan. Figure 2. Virtual tooth relative to the implant supporting bone ready for implant planning. Figure 3. Radiographic guide incorporating teeth to be replaced with their cervical contours (left) and resulting surgical template with guiding sleeves (right).


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  <sc>Figure</sc>
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Figure 4.

(a) Immediately loaded maxillary complete arch. (b) Maxillary partial arch. (c) Immediately loaded mandibular single tooth.


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  <sc>Figure</sc>
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Figure 5.

Influence of implantation site on implant survival. Implant survival is highest in the anterior mandible (100%), followed by the anterior maxilla (94%), posterior mandible (92%), and posterior maxilla (78%). (Modified from Schnitman et al.9)


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  <sc>Figures 6 and 7.</sc>
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Figures 6 and 7.

Figure 6. Single tooth implant in maxillary 2nd premolar area. (a) The radiograph at 1-year follow-up showing excellent bone maintenance with the implant apex appearing to be in sinus. (b) Screen shot from the computer planning software showing ability to position implant to maximize bone support with apex engaging cortex between sinus and buccal plate while maintaining the relationship to prosthetically driven position. Figure 7. Maxillary three-tooth restoration supported by implants in the 1st bicuspid and 1st molar region. (a) Screen shot from the computer planning software showing the 1st premolar implant placement to maximize bone density while maintaining the prosthetically driven implant position. (b) Radiograph at 1-year follow-up of 1st bicuspid implant showing excellent bone maintenance. (c) Screen shot from the computer planning software showing tilted implant to exit in 1st molar position, paralleling the anterior wall of the sinus with 13 mm implant entirely within host bone avoiding the need for a sinus graft.


Contributor Notes

Corresponding author, e-mail: pschnitman@aol.com
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