ENG
Development of osseointegration has rapidly led to the use of dental implants in recent years. Dental implants have become a treatment option for the replacement of lost teeth. Accurate implant guide plate is of importance for the success of implant surgery. How to make an accurate implant guide plate? This article will discuss this topic from the point of view of guide printing.
What’s the digital implant surgical guide plate?
CBCT data and intraoral scan data (or plaster model data) are used to reconstruct the three-dimensional of patients’ oral and face. Taking all factors, such as patients’ lost teeth, bone situation, important anatomical marks into consideration, technicians design a most suitable implant surgical guide plate to allow a dentist to place an implant body in a very specific, pre-planned location to give the most ideal depth, angle, and the size of implant to fit the space（Fig1）.
Fig1：The surgical guide plate
Why we need implant surgical guide plate?
There are several advantages of implant surgical guide plate. It reflects the preoperative setting site accurately to achieve restoration-oriented implant treatment. It guides the process of the implant surgery, reduces the operation time. The non-flap technique accelerates mucosal healing with less bone loss, and brings less postoperative discomfort.
Reasons that lead to the inaccuracy of the implant surgical guide plate
Data error, design/printing deviation and operation are the three main reasons for the failure of implant operation. Data error includes inaccurate CBCT, like oral movement artifacts, intraoral scan data deviation or the poor alignment. Misoperation is something like the placement of the guide plate in the mouth is not accurate, the gap value between guide ring and drill needle is not appropriate, etc. The design/printing deviation is whether the design of the guide plate is reasonable, or the process of guide plate printing is controllable, or the assemble of the guide ring and guide plate is correct, and so on.
How to print an accurate guide plate?
- The adjustment of printer
3D printer can be used to make the implanting guide plate with photosensitive resin. Before using, in the equipment debugging stage, the accuracy and consistency of printing are ensured by adjusting the two parameters of scale compensation and contour compensation (Fig 2). Besides, set appropriate guide plate parameters, such as, thickness, tooth/model offset, amount of concave retention, and compensation from guide ring.
Fig 2: the interface you can adjust the scale compensation and contour compensation
- The layout and design before printing
- The printing thickness and steps on the side walls
If the guide hole is not vertical while printing, there will be steps on the side walls which result in resistance when the guide ring is placing. The thicker the layer, the faster the printing speed, the more obvious the step pattern on the side walls (Fig 3). To avoid the steps, it is recommended to layout the component with its guide hole vertical to the printing platform (Fig 4).
Fig 3: The interface to adjust the layer thickness before printing
Fig 4: Layout the component with its guide hole vertical to the platform
- The support adjustment
Remove the support inside the guide hole. If there are supports inside the guide hole, the refine grinding will leads to the deviation of the guide plate. The top support is spherical (Fig 5), it makes easier for us to remove the support after printing. The base is shaped like a boat, then we can remove the parts using knife easily. Adjust the diameter of the spherical and the support rod carefully. An experienced user can adjust the support with perfect parameters that strong enough to hold the parts and suitable to remove at the same time(Fig 7).
Fig 5: The spherical top support
Fig 6: the base is shaped like a boat for easier removing.
Fig 7: Generate support
- The resin for guide plate printing
Different photosensitive materials have different clinical applications in dental industry. Shining 3D have several different kinds of photosensitive resins（Fig 8）. To print surgical guide, we recommended photosensitive SG01(Fig 9), which had been tested and verified with biocompatibility. To minimize the deviation of the printing process, the requirement of temperature is between 20℃ and 30℃, the humidity is round 25%. In this condition, the swelling of the liquid is small, thus ensuing higher accuracy of the printing components.
Fig 8: Different kinds of resins provided by Shining3D.
Fig 9: The Surgical Guide resin SG01 provided by Shining3D.
- The post-processing
Cleaning the components with IPA ≥90% or ethanol ≥90% until the surface does not feel sticky, if necessary, use ultrasonic oscillating equipment or interdental brush. After cleaning, dry the components with compressed air. Assemble the guide ring with guide plate before curing in the FabCure 2.0 (Fig 10), then post curing for a recommended time.
Fig 10: Fabcure 2.0, a device for post curing light
To recap, these are strategies to print surgical guide plate.
For surgical guide plate without guide ring：
- Ensure the guide holes are vertical. In this way, the inner wall is smooth, and there is no resistance when the drill needle enters.
- No support on fitting surface.
- Fully expose observation and cooling windows, observation window helps dentists to check whether the guide plate is placed on the dental arch completely. The cooling window is where the cool water injects to avoid bone burn during operation.
For surgical guide plate with guide ring:
- Ensure the guide holes are vertical and common path of insertion.
- Check carefully to make sure there is no support around the guide ring and bonding hole.
- Expose observation and cooling windows.
- Enough support at the lowest point of the components.
