|Year : 2017 | Volume
| Issue : 1 | Page : 11-14
A simple technique for fabrication of a surgical guide for predictable placement of dental implants
MC Suresh Sajjan1, Prem Sagar Yekula1, Sai Sudha Kovvuri2, Rama Raju Venkata Alluri1
1 Department of Prosthodontics and Implantology, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
2 Department of Periodontics and Implantology, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
|Date of Web Publication||13-Feb-2018|
Dr. M C Suresh Sajjan
Department of Prosthodontics and Implantology, Vishnu Dental College, Bhimavaram, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Surgical guide plays a crucial role to facilitate optimal positioning and angulation of implants. Nonlimiting designs guide only the position but not the angulation of implant placement. This article describes a simplified technique of fabricating a surgical guide to limit the freedom of implant placement. In addition, it also has an advantage of holding the flap away from the operating site by means of a flange extended onto the buccal slope, allowing adequate visibility during the osteotomy preparation.
Keywords: Flap reflection, implant placement, implant surgical guide
|How to cite this article:|
Suresh Sajjan M C, Yekula PS, Kovvuri SS, Venkata Alluri RR. A simple technique for fabrication of a surgical guide for predictable placement of dental implants. J Dent Implant 2017;7:11-4
|How to cite this URL:|
Suresh Sajjan M C, Yekula PS, Kovvuri SS, Venkata Alluri RR. A simple technique for fabrication of a surgical guide for predictable placement of dental implants. J Dent Implant [serial online] 2017 [cited 2018 Feb 23];7:11-4. Available from: http://www.jdionline.org/text.asp?2017/7/1/11/225401
| Introduction|| |
Surgical guide plays an imperative role to facilitate optimal positioning and angulation of implants. It is an essential element to transfer the diagnostic and prosthetic planning information to the surgical phase. Implant placement should be prosthodontically driven because the desired prosthodontic position influences the emergence profile that fulfills the esthetic requirements. The surgical guide dictates the implant placement that offers the best combination of support for the repetitive forces of occlusion, esthetics, and hygiene requirements. The guide should be stable and rigid when placed in position during osteotomy. In cases of fewer missing teeth in one quadrant, the guide should fit over or around enough teeth to stabilize it in position. A well-developed plan should be transferred accurately, giving less scope for modifications at the time of surgery.
Several methods have been described for fabrication of implant surgical guide. Some are designed for the placement of a single implant, while others for multiple implants, implant-fixed partial dentures, and implant-retained overdentures. Three techniques commonly used for preparing the guide holes in the fabrication of surgical guides are free-hand, milling, and the use of computer-aided design (CAD) computer-assisted machining technology.,,, In the free-hand technique, an acrylic resin bur is used to mark the cast as a guide for parallel insertion without a fixed apparatus stabilizing the bur. This technique poses risks because parallel implant placement may be variable. Two designs using a freehand technique have been reported – slot , and individual hole., Nonlimiting designs guide only the position of crest module and not the angulation of implant placement. This in turn poses several esthetic problems and also invariably leads to either vertical or horizontal cantilevering in the definitive prosthesis. The slot design may permit for change in the buccolingual axis of osteotomy preparation. The individual hole design would permit freedom to alter the axis in all the directions. However, any change in the axis of implant placement would affect the prosthodontic outcome. It is desired to design surgical guide so as to prevent freedom to alter the axis of the osteotomy.
Another difficulty experienced while doing the surgery is that the flap would fall back and block the visualization. Hence, it requires additional hands to retract the flap and allow the surgeon to get a full view of the surgical site. Some clinicians found to suture the flap to the adjacent mucosa either buccally or labially. At times, this can cause a tear in the mucosa or flap if incorrectly done. Hence, there is a need to simplify the procedure for precise placement of implants and also to hold the flap away from the osteotomy site.
This article describes a simplified technique of fabricating a surgical guide combining both the slot and individual hole designs to limit the freedom of implant placement. In addition, it also has an advantage of holding the flap away from the operating site by means of a flange extended onto the buccal slope, allowing adequate visibility during the osteotomy preparation.
| Technique|| |
- Mount the diagnostic casts prepared in Type III dental stone to a semi-adjustable articulator using face-bow transfer
- Do diagnostic wax-up of missing teeth to full contour in occlusion
- Block undercut areas around the teeth adjacent to edentulous area using baseplate wax and coat the area using cold mold seal
- Apply autopolymerizing clear acrylic resin covering the waxed up teeth and the teeth adjacent to edentulous area, extending up to the sulcus depth on the lingual side and occlusal one-third of the teeth on the buccal side maintaining the thickness at 1.5 mm
- In case one of the adjacent teeth is not present, extend the guide onto the edentulous area beyond surgical site
- After polymerization of the resin, mark a point coinciding the central fossa of the waxed up teeth on the surgical guide
- Retrieve the guide and remove waxed up teeth leaving a hollow space
- Apply cold mold seal to the edentulous area and position the guide back on the cast
- Apply autopolymerizing clear acrylic resin, covering the edentulous area extending buccally onto the slope of the ridge up to the sulcus depth [Figure 1]. Maintain the flange thickness at 1.5 mm
- Transfer the cast onto a milling machine/surveyor
- Analyze the optimal direction of implant by long axis of the adjacent teeth and draw a line on the cast to indicate the direction of implant placement
- Secure a no. 2 parallel cutter, cross-cut, round tip bur of diameter 2.2 mm to the handpiece of milling machine and drill a hole on the guide at the marked point. Bring down the handpiece such that another hole gets drilled on the flange over the edentulous area, following the predetermined direction for implant placement
- Create a slot extending up to the hole on the occlusal aspect of the guide such that it is open to the buccal side [Figure 2]
- Retrieve the guide from the cast and trim, finish, and polish [Figure 3]
- Usage of the guide - After reflection of the flap, the guide is kept in position so that the buccal flange goes under the flap [Figure 4] to prevent the flap from coming back to the osteotomy site
- Position the 2 mm osteotomy drill to have two-point contact, one at occlusal level and the other at ridge level with the tip through the hole made on the edentulous area and perform the osteotomy [Figure 4].
| Discussion|| |
Optimum prosthetic outcome of implant prosthesis depends upon two factors  – position of the crest module of implant and  direction of the implant body. The direction of implant body in turn determines the need to use any angulated abutment or customized abutments. Additional components like these would add up to the cost of the procedure. Use of completely limiting surgical guides can best provide optimum position for an implant satisfying both the conditions. However, the CAD milled surgical guides as completely limiting guides are still economically not viable to a larger population in developing countries. The present technique provides a simplified approach to satisfy both the conditions to optimize implant position and can also be prepared by the practitioner in the dental office.
The surgical guide should help in transferring the predetermined angulation and control the position of drill in all the three dimensions while doing the osteotomy preparation. This requires at least two reference points: one at the crestal level and another about 8 mm higher at occlusal level. These two points can be joined by a line that represents the path of ideal implant insertion. The ideal angulation is perpendicular to the occlusal plane and parallel to the most anterior abutment (natural or implant) joined to the implant. The direction and depth of osteotomy are first determined by a 2-mm twist drill. Further osteotomies will follow this predetermined initial drill. In the proposed surgical guide, the two points are located in the form of a slot on the occlusal aspect and a hole on the flange above the crest of the ridge.
The technique presented is intended to guide the clinician to do accurate osteotomy site preparation with improved visibility and accessibility. Visualization is improved as the design of the guide incorporates an opening toward the buccal side. Accessibility is improved by two means: the guide has a flange extended onto slope of the ridge that keeps the flap away from the osteotomy site and prevents the flap from falling back onto the surgical area. This enables an assistant also to visualize the surgical site without interruption to guide the surgeon for correct positioning and depth. A slot is provided on the occlusal aspect so that in situ ations where the mouth opening is less than optimum or in the cases of most posterior implant placements, the pilot drill can be taken into final position through the slot from the buccal aspect rather than from the occlusal aspect.
The novel approach of fabricating the surgical guide described above allows precise placement of implants in the planned position, thereby a predictable treatment outcome is ensured [Figure 5]. In situ ations where there is availability of sufficient width of alveolar bone, this surgical guide can also be used for flapless technique.
| Conclusion|| |
This article describes fabrication of a surgical guide for ideal placement of implants by enabling an operator to have adequate visibility and accessibility. This is a simplified procedure of making surgical guide and can be fabricated using conventional materials, and it can be applied to most of the clinical situations.
Financial support and sponsorship
The study was supported by Vishnu Dental College.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]