Computer Guided Implantology PDF

## Computer Guided Implantology ### Definition & Implant Placement Using a Surgical Template - Implant placement using a surgical template that is fabricated using a digital maneuver. ### Departments Share in Computed Guided - Surgery - Radiology - Fixed Prosthodontics - Removable Prosthodontics...

## Computer Guided Implantology ### Definition & Implant Placement Using a Surgical Template - Implant placement using a surgical template that is fabricated using a digital maneuver. ### Departments Share in Computed Guided - Surgery - Radiology - Fixed Prosthodontics - Removable Prosthodontics ### Cast Based Surgical Guide (in Past) History - By taking an impression of the patient, creating a cast, and fabricating a surgical guide on it. - Different designs according to whether the patient was completely or partially edentulous, and whether placing a single implant or two or three implants next to each other, whether it's transparent or not, and according to the preference. This resulted in a wide variety of surgical guide designs. - The only benefit was that it determined the point of entry. ### After That, a Paradigm Shift Occurred - From 2D (periapical, panorama) to 3D (CBCT, CT) imaging. - From manual to digital. - From surgically driven to prosthetically driven implant placement. ### From 2D to 3D Imaging - **Merits of Cross-Sectional Imaging** - No Superimposition - Better Planning. - Representation of the 3rd dimension - Bucco-Lingual. - Decrease Complications of implant placement. - Free of Shape distortion. - Minimal size distortion. - Although in CBCT the resolution is 1.1, there is still an error margin of about 0.5mm, that’s why it cannot be relied on 100%. That’s why Safety margin was established, because machines can introduce a 0.5 mm error and this error may increase slightly during planning. - **Limitations of Cross-Sectional Imaging** - Increased Radiation dose - Patients should be exposed to justifying radiations. - Steep Learning Curve. - Increased number of images. ### From Manual to Digital - Fewer Steps - Save time. - Reduced human interaction - Fewer errors. - In return, the cost increased. ### From Surgically Driven to Prosthetically Driven Implant Placement - I needed the future prosthesis first and then perform the surgery based on it, considering the surgical requirements. ### These 3 Shifts Increase the Chance of Computed Guided Implantology ### Functions of Surgical Guide - Determines point of entry. - Controls the direction of drilling. - Controls the length. - Maintain parallelism (if needed). ### Advantages #### Flapless - Decreased Chairdside time. - Less required surgical skills. - Decreased post-operative pain. - Decreased post-operative edema. - Decreased initial bone resorption. #### Pre-Operative Planning - Predictable. - High functional outcome. - High esthetic outcome. - High biological outcome. ### Steps of Computed Guided Implant Placement 1. CBCT or MSCT scanning 2. Treatment Planning 3. Surgical guide designing 4. Surgical guide fabrication 5. Surgery performing - Treatment planning and surgical guide designing can be done on a separate software program or in a single software program that could achieve the steps together. ### CBCT or MSCT Scanning #### CBCT vs MSCT - **CBCT** - Less Radiation dose. - Interactive software. - Lower Cost. - Higher spatial resolution. - The main factor affecting the spatial resolution is the voxel size. - Voxel size ↓ — Resolution ↑ - In CBCT it gives a qualitative value for bone density not a quantitative value. - In CBCT, it's ranged from 0.4mm - 0.075mm. - Ideal for implant placement 0.3mm - 0.1mm. - Reasonable amount of radiation and sufficient image resolution 0.0.75mm. - **MSCT** - Better Contrast Resolution. - Considered in soft tissues. - Bone density gives a numerical value for bone density. - Lowest Resolution - Least dose. - Highest Resolution - Highest dose. ### Field of View (FOV) - You can customize the field of view. - Adjust the FOV according to the area you will be working on. - A large FOV exposes you to 2 problems: 1. From ethical and legal aspects you have to examine and detect any problems appearing in the x-ray image. 2. Expose the patient to unneeded radiation dose. **Except**, in Computer Guided Surgery you need to capture the entire arch, even if the patient has only a single implant, to stabilize the guide on the arch. ### CBCT Scan Requirements for Surgical Guide Fabrication 1. Opposing arch must be visible to ensure proper occlusion. 2. The two arches must be separated. Patient should bite on a radiolucent bite material or a cotton roll to ensure the arches are separated. 3. Eliminate the metal artifacts by metal artifact reduction algorithm (MAR). 4. Eliminate the noise in CBCT (granny images cannot be used in surgical guide). 5. Covering area of interest. 6. Voxel site - 0.2 - 0.3 mm. ### Treatment Planning using CBCT - **Informations obtained from CBCT** - Implant or not. - Graft or not. - Sinus lift or not (open or closed). - Time of implantation (immediate or delayed, indicated if there is sufficient bone needed for primary stability, immediate implant is not preferable if there is an infection). - Fixed or removable (go for removable-retained if there is no enough bone for more than 2-3 implants, removable used in large interarch space, removable used in patients need lip support by flanges of removable prosthesis). - Implant length and diameter. - Number and distribution of implants according to available bone. - Cervico-apical position of the implant. - Angulation of the implant. ### Display Modes - **Multiplanar Reconstruction (orthogonal)** - not used. - **Oblique Multiplanar Reconstruction (Axial, Coronal, Sagittal)** - **Panoramic + Serial Cross-Section** - **Volume Rendering** - not used. **Oblique Multiplanar** - Measurements are more accurate, but it's very critical so it needs accurate measurements. - In multiplanos: - **Posterior Region** - Coronal measures height and bucco-lingual width. - Sagittal measures mesio-distal. - **Anterior Region** - Coronal measures mesio-distal. - Sagittal measures height and labio-palatal width. #### **Panoramic + Serial Cross-Section** - Overall view. - Measurements are not as accurate because it's not as accurate as in oblique multiplanar, so you may not get a perfect result in a serial cross section, which will affect the accuracy of measurements. ### Types of Surgical Guide - **Teeth Supported** - Fabricated for partially edentulous patients using teeth as support for the guide. - At least 3 healthy teeth should be present in the arch. - **Mucosa Supported** - Fabricated for completely edentulous patients or patients with less than 3 healthy teeth available. - These guides are secured during surgery with the help of fixation screws to prevent its movement. - Inter-arch records are made to determine the vertical dimension. - **Bone Supported** - Fabricated in completely edentulous or partially (long span) edentulous patients. ### Levels - **Level 1** - CBCT extracted information (bone height, mesio-distal length, bucco-lingual depth, bone morphology, angulation, integrity and thickness of cortical plates, bone density, inter-arch space). - **Level 2** - Implant simulation (nerve tracing, implant simulation, implant library, implant verification). - **Level 3** - Surgical guide usage (designing, fabrication). - **Level 4** - Implant navigation. #### Scanning Appliance - **Partially edentulous** - Few missing teeth: No scanning appliance. - Many missing teeth: Vacuum-based scanning appliance. - **Fully edentulous** - Denture-based scanning appliance. - **Vacuum-based scanning appliance** - Hard night guard with radio-opaque markers. - **Denture based scanning appliance** - Dentist fabrication of denture. - **A proper fit denture with radio-opaque markers must be fabricated for patients that don’t have dentures, ill-fitting dentures, or dentures that need to be retired. Dentures used must be retentive.** ### Requirements For Designing Surgical Guides - **CBCT or MSCT Scan** - Scan for patient teeth. - Scanning appliance (may or may not be needed). ### Scanning Protocols - **Single Scan** - Use only CBCT scan with or without a scanning appliance (preferable to use to avoid artifacts and soft tissue problems). - **Double Scan** - CBCT + intra-oral scanning directly (laser scan to the cast) or intra-oral scan (direct). - **CBCT scan does not have the ability to differentiate between soft tissues. This means a CBCT scan is not enough for patients with metallic restorations as it will result in artifacts. So fabrication of surgical guide will be affected.** Therefore, **patients with metallic restoration should be scanned by extra-oral or intra-oral scanners.** ### Partially Edentulous Patient - CBCT scan with or without a scanning appliance, according to the number of remaining teeth. - Separated scan of teeth. - If you have removed teeth, do intra-oral or extra-oral scanning. - Scanning appliances with radio-opaque markers (Barium Sulphate, Composite, Gutta Perchas). - The anterior is more critical than posteriors in prosthetically driven implant placement. ### Completely Edentulous Patient - The denture must be fabricated first. - Then put radio-opaque markers on the denture (14-6 markers). - Put them buccally or lingually, don't put them occlusally (with markers). - **CBCT scan alone for the patient with denture and one for denture alone without the patient: Dual scan** - **Dual scan is used, due to the poor contrast resolution of CBCT. It hasn't the ability to differentiate between the denture base and the soft tissue.** - Denture base and soft tissue appear with the same color (with markers). - As soon as you scan the denture alone, you can differentiate between the denture base and the surrounding soft tissue, which is what you would use to create a surgical guide for the mucosa of the patient. ### Then on The Software You Can Superimpose The Images (Patient Wearing The Denture And The Denture Alone Without Mucosa) - Patient must bite properly to ensure the denture fits securely in completely edentulous patients. - For partially edentulous patients, software can superimpose the cast on the CBCT of the patient. - Arches must be separated (by cotton rolls) during the CBCT scan. ### Surgical Guide Fabrication - **Technology** - Rapid prototyping. - 3D printing. - Stereolithographic STL file. **Terminology** - **Rapid prototyping** - Process of creating a physical model directly from a digital design. - **Types -** - **Subtractive** - Layer by layer, additive in implant surgical guides. - **Additive** - Dependant on additive. - **Subtractive** has 2 major drawbacks: 1. Material waste. 2. Inability to handle undercuts. - **We depend mainly on additive rapid prototyping - 3D printing.** - **Subtractive** - milling. **If you're performing 3D printing using a liquid resin, the process is called Stereolithographic (a technique performed using liquid resin).** - **STL File** - The file format that 3D printers typically understand (Standard Tessellation Language). - **You need Dicom file from CBCT and STL file for a surgical guide.** **How could I get a surgical guide?** - **Software to create STL file.** - **3D printers to use the STL file to fabricate surgical guides.** ### Software - **Nobel Biocare:** Nobelguide - **Materialise:** Simplant - Mimics - **3Shape:** Implant studio - **Dental wings:** Codiagnostix - **Cybermed:** In2guide - **BlueSkyBio:** Blue scan plan - **Dentsply Sirona:** Galileos implant - **Biodenta:** Bioguide ### Surgery Performing - **How can I fix the template?** - **Types** - Fixing screws, fixing pins (anchor pins). - **Numbers** - 9.5, 2 or 3 buccal, 1 or 2 palatal. - **Types of Surgical Guiding** - **Partially Guided:** Guices considered fully only if implant placement is done with the presence of the guich inside the patient's mouth. - **Fully Guided:** Nowadays. Higher accuracy. - **Keys are used to stabilize the drills inside the surgical guides, to ensure precision.** - **You need software to design and create an STL file for 3D printing. Then 3D printing creates the surgical guide. Then, you need a compatible surgical kit.** ### Limitations of Surgical Guides - **Visibility**, **irrigation**, **limited mouth opening**. - Overcome these problems by modified surgical guide (C-style. ### Disadvantages of Surgical Guides - **Complications during surgery (fracture-unfitted), difficult to use it in limited mouth opening, added cost, accuracy (because you are working blindly).**