**Lecture 6: Impression and Soft Tissue Management** By Dr Cheryl Fu # **Lecture 6: Impression and Soft Tissue Management** By Dr Cheryl Fu **Learning Objectives** 1. Define the objectives of definitive impressions. 2. Discuss the impact of subgingival margins on the soft tissue management. 3. Define the aims of gingival displacement and describe the different methods of gingival displacement. 4. Discuss the importance of impression timing 5. Describe the ideal impression. 6. Impression material properties Reading: Fundamentals of Fixed Prosthodontics Chapter 14 + # **Learning Objectives** 1. Define the objectives of definitive impressions. 2. Discuss the impact of subgingival margins on the soft tissue management. 3. Define the aims of gingival displacement and describe the different methods of gingival displacement. 4. Discuss the importance of impression timing 5. Describe the ideal impression. 6. Impression material properties **Reading:** Fundamentals of Fixed Prosthodontics Chapter 14 + # Impression Restorations which fit exactly and can be inserted without any further corrections ## Exact fitting restorations: - More efficient and faster working - Aid periodontal prophylaxis, caries - Aesthetic results - Prognosis **Table 2. Periradicular status for various combinations of treatment quality** | Group | Endo | Coronal | No. teeth | PPI | API | %API | |-------|------|---------|-----------|------|-------|------| | 1 | Good (GE) | Good (GR) | 330.5 | 28.5 | 302.0 | 91.4 | | 2 | Good (GE) | Poor (PR) | 164.5 | 92.0 | 72.5 | 44.1 | | 3 | Poor (PE) | Good (GR) | 302.5 | 98.0 | 204.5 | 67.6 | | 4 | Poor (PE) | Poor (PR) | 188.0 | 154.0| 34.0 | 18.1 | PPI, presence of periradicular inflammation. API, absence of periradicular inflammation. **Table 3. Success rate of endodontic treatment of good or poor quality in teeth with good or poor coronal restorations** | Endodontic treatment | Coronal restoration | n | Failure | Success | Success in percent | |----------------------|---------------------|-----|---------|---------|---------------------| | GE | GR | 364 | 70 | 294 | 81%* | | GE | PR | 142 | 41 | 101 | 71%* | | PE | GR | 299 | 131 | 168 | 56%* | | PE | PR | 196 | 85 | 111 | 57%* | GE = Good Endodontics; PE = Poor Endodontics; GR = Good Restoration; PR = Poor Restoration. * The difference between the success rate with Good Endodontics and Poor Endodontics was statistically significant (P<0.0001) regardless of the quality of the coronal restoration (GR or PR). Ray HA, Trope M. 1995 Tronstad L, Asbjørnsen K, Døving L, Pedersen I, Eriksen HM. 2000 # **Impression** Restorations which fit exactly and can be inserted without any further corrections > [!failure] Consequences of a Poor Impression > A poor impression, whether conventional or digital, will inevitably result in a poor-fitting restoration. > - ==**Guesswork:** The dental lab may have to guess the location of margins if they are unclear.== > - ==**Distortions:** The restoration may fit the lab model but not the actual tooth in the patient's mouth.== > - ==**Inefficiency:** This leads to repeated impressions, wasting chair time and materials. A single failed PVS impression can cost over $20 in materials alone.== > - ==**Periodontal Issues:** Inaccurate margins can lead to plaque retention, increasing the risk of gingival inflammation and recurrent caries. Assessing caries can be difficult under radio-opaque crowns (e.g., zirconia, metal).== > - ==**Aesthetic Impact:** Distortions can negatively affect the final shape and appearance of the crown.== > - ==**Endodontic Success:** The quality of the final restoration directly impacts the long-term success of endodontic treatment. Studies show that a poor restoration significantly increases the presence of periapical infections, even with good endodontic work.== ## **Exact fitting restorations:** - More efficient and faster working - Aid periodontal prophylaxis, caries - Aesthetic results - Prognosis **Table 2. Periradicular status for various combinations of treatment quality** | Group | Endo | Coronal | No. teeth | PPI | API | %API | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | 1 | Good (GE) | Good (GR) | 330.5 | 28.5 | 302.0 | 91.4 | | 2 | Good (GE) | Poor (PR) | 164.5 | 92.0 | 72.5 | 44.1 | | 3 | Poor (PE) | Good (GR) | 302.5 | 98.0 | 204.5 | 67.6 | | 4 | Poor (PE) | Poor (PR) | 188.0 | 154.0 | 34.0 | 18.1 | PPI, presence of periradicular inflammation. API, absence of periradicular inflammation. **Table 3. Success rate of endodontic treatment of good or poor quality in teeth with good or poor coronal restorations** | Endodontic treatment | Coronal restoration | n | Failure | Success | Success in percent | | :--- | :--- | :--- | :--- | :--- | :--- | | GE | GR | 364 | 70 | 294 | 81%* | | GE | PR | 142 | 41 | 101 | 71%* | | PE | GR | 299 | 131 | 168 | 56%* | | PE | PR | 196 | 85 | 111 | 57%* | GE = Good Endodontics; PE = Poor Endodontics; GR = Good Restoration; PR = Poor Restoration. \* The difference between the success rate with Good Endodontics and Poor Endodontics was statistically significant (P<0.0001) regardless of the quality of the coronal restoration (GR or PR). Ray HA, Trope M. 1995 Tronstad L, Asbjørnsen K, Døving L, Pedersen I, Eriksen HM. 2000 # Impression ## Impression Objectives: 1. Exact duplication of the prepared and uncut tooth beyond the preparation to allow evaluation of location and configuration of finishing line 2. Duplicate other teeth and soft tissue to permit proper articulation of the cast and contouring the restoration 3. Must be free of bubbles specially at finishing line and prepared surfaces ## **Impression Objectives:** 1. Exact duplication of the prepared and uncut tooth beyond the preparation to allow evaluation of location and configuration of finishing line 2. Duplicate other teeth and soft tissue to permit proper articulation of the cast and contouring the restoration > [!info] > This is crucial for the lab to create proper interproximal contacts and natural contours for the restoration. 3. Must be free of bubbles specially at finishing line and prepared surfaces # Impression **Aim of impression**: produce a dimensionally stable “negative” - Mould for an analogue model - Scanned with CAD/CAM model Milled Model 3D Printed Model ## **Aim of impression**: produce a dimensionally stable “negative” - Mould for an analogue model - Scanned with CAD/CAM model - Milled Model - 3D Printed Model # Impressions ## Impression/Scanning Prerequisites - Tissue management - Gingival tissue displacement (if needed) - Saliva control - Adequate impression/scanning technique ## **Impression/Scanning Prerequisites** - Tissue management - Gingival tissue displacement (if needed) - Saliva control > [!info] > This includes managing saliva, blood, and gingival crevicular fluid. - Adequate impression/scanning technique **Tissue management** - Careful preparation - Hard tissue - Soft tissue - Atraumatic procedure - Well-contoured provisional restoration - Adequate oral hygiene **Tooth Preparation** - Supragingival margins if possible - Minimally subgingival or intra-crevicular - Well-defined, smooth and continuous margins - Well-finished and tidy preparation - Atraumatic to gingival tissues # **Tissue management** - Careful preparation - Hard tissue - Soft tissue - Atraumatic procedure - ==Care must be taken to not damage adjacent teeth, as bleeding can compromise the impression.== - Well-contoured provisional restoration > [!tip] > A well-fitting temporary crown with smooth margins prevents plaque accumulation and gingival inflammation, ensuring the tissues are healthy at the final impression appointment. Patients should be instructed on how to floss around temporaries (e.g., pulling floss through the side rather than back up through the contact) to avoid dislodging them. - Adequate oral hygiene ## **Tooth Preparation** - Supragingival margins if possible - Minimally subgingival or intra-crevicular - Well-defined, smooth and continuous margins - Well-finished and tidy preparation - Atraumatic to gingival tissues **Tissue management - supragingival preparation** Supragingival preparation Three clinical images showing stages of supragingival tooth preparation. ## **Tissue management - supragingival preparation** Supragingival preparation > [!info] > Whenever possible, **supragingival** or **equigingival** margins are preferred as they make tissue management and impression-taking significantly easier. However, subgingival margins may be necessary for aesthetic reasons (e.g., anterior teeth) or to cover existing deep restorations. **Biologic width** We risk violation of **biologic width!** KNOW THIS WORD! Slide by Dr Matsubara Clinical image of anterior teeth with red arrow pointing to gingival margin, illustrating potential biologic width violation. # **Biologic width** We risk violation of **biologic width!** KNOW THIS WORD! > [!warning] Violation of Biologic Width > Placing a restoration margin too deep within the sulcus can impinge on the biologic width, leading to: > - ==Persistent chronic inflammation.== > - ==Clinical attachment loss, including alveolar bone loss and gingival recession.== > > **Assessment:** Biologic width can be assessed using **bone sounding**, where a periodontal probe is used under local anesthetic to measure the distance to the alveolar crest. The sulcus depth is then subtracted from this measurement. A violation is diagnosed if the resulting distance is less than 2 mm. *Slide by Dr Matsubara* **Biologic width** Connective tissue 1.07 mm Junctional epithelium 0.97 mm Gingival sulcus 0.5-1 mm **Biologic Width 2 - 2.25 mm** **Margin location** ► If the margins has to be subgingival it should only be placed intracrevicularly ► Maximum depth around 0.7mm *Slide by Dr Matsubara* ## **Components of Biologic Width** - Connective tissue 1.07 mm - Junctional epithelium 0.97 mm - Gingival sulcus 0.5-1 mm - **Biologic Width 2 - 2.25 mm** ### **Margin location** - ► If the margins has to be subgingival it should only be placed intracrevicularly - ► Maximum depth around 0.7mm > [!info] > Subgingival margins are associated with a higher risk of gingival inflammation due to factors like defective margins, surface roughness, and improper crown contour. *Slide by Dr Matsubara* **Biologic width** **Take Home Message:** If you place a margin within 2mm of the crestal bone you will get inflammation, followed by bone loss as the biological width tries to re-establish itself Slide by Dr Matsubara Want to know more about biologic width? Read: Mulla SA, Patil A, Mali S, Jain A, Sharma D, Jaiswal HC, Saoji HA, Jakhar A, Talekar S, Singh S. Exploring the Biological Width in Dentistry: A Comprehensive Narrative Review. Cureus. 2023 Jul 18;15(7). <table> <thead> <tr> <th>Condition</th> <th>Measurement</th> </tr> </thead> <tbody> <tr> <td>Normal Crest</td> <td>3 mm (4 approx)</td> </tr> <tr> <td>High Crest</td> <td>&lt; 3 mm (4 approx)</td> </tr> <tr> <td>Low Crest</td> <td>&gt; 3 mm (4 approx)</td> </tr> </tbody> </table> Diagram showing four cross-sectional views of periodontal structures labeled Normal Crest, High Crest, and Low Crest with corresponding measurements. **Biologic width** Normal Crest 3 mm (4 approx) High Crest < 3 mm (4 approx) Low Crest > 3 mm (4 approx) **Take Home Message:** If you place a margin within 2mm of the crestal bone you will get inflammation, followed by bone loss as the biological width tries to re-establish itself Slide by Dr Matsubara Want to know more about biologic width? Read: Mulla SA, Patil A, Mali S, Jain A, Sharma D, Jaiswal HC, Saoji HA, Jakhar A, Talekar S, Singh S. Exploring the Biological Width in Dentistry: A Comprehensive Narrative Review. Cureus. 2023 Jul 18;15(7). **Biologic width** **Take Home Message:** If you place a margin within 2mm of the crestal bone you will get inflammation, followed by bone loss as the biological width tries to re-establish itself **Normal Crest** 3 mm (4 approx) **High Crest** < 3 mm (4 approx) **Low Crest** > 3 mm (4 approx) Want to know more about biologic width? Read: Mulla SA, Patil A, Mali S, Jain A, Sharma D, Jaiswal HC, Saoji HA, Jakhar A, Talekar S, Singh S. Exploring the Biological Width in Dentistry: A Comprehensive Narrative Review. Cureus. 2023 Jul 18;15(7). Slide by Dr Matsubara Four diagrams illustrating Normal, High, and Low Crest scenarios relative to the biological width, with accompanying text labels and a take-home message. ## **Take Home Message** If you place a margin within 2mm of the crestal bone you will get inflammation, followed by bone loss as the biological width tries to re-establish itself. *Slide by Dr Matsubara* ## **Crest Types** <table> <thead> <tr> <th>Condition</th> <th>Measurement</th> </tr> </thead> <tbody> <tr> <td>Normal Crest</td> <td>3 mm (4 approx)</td> </tr> <tr> <td>High Crest</td> <td>&lt; 3 mm (4 approx)</td> </tr> <tr> <td>Low Crest</td> <td>&gt; 3 mm (4 approx)</td> </tr> </tbody> </table> **Further Reading:** Want to know more about biologic width? Read: Mulla SA, Patil A, Mali S, Jain A, Sharma D, Jaiswal HC, Saoji HA, Jakhar A, Talekar S, Singh S. Exploring the Biological Width in Dentistry: A Comprehensive Narrative Review. Cureus. 2023 Jul 18;15(7). Based on bone sounding, patients can be categorized into three types: - ==**Normal Crest (85% of patients):** The measurement from the gingival margin to the bone crest is 3-4.5 mm. These tissues are stable and can tolerate a subgingival margin of about 0.5 mm without adverse effects. They recover well from minor trauma, such as from a retraction cord.== - ==**High Crest (2% of patients):** The measurement is less than 3 mm. The bone is high, meaning the biologic width is narrow. Placing a margin subgingivally in these patients will almost certainly impinge on the biologic width, leading to persistent inflammation.== - ==**Low Crest (13% of patients):** The measurement is greater than 4.5 mm. These patients have a large biologic width. The attachment is fragile and susceptible to damage from retraction cords, often resulting in gingival recession as the tissue heals back to a “normal crest” position.== **Biologic width** The margins of the restoration can be positioned 0.5 mm below the gingival tissue crest if the probing depth of the sulcus is 1.5 mm or less. If the sulcus depth is more than 1.5mm, then the margins of the restoration should be inserted in the sulcus at a depth that is half its probing depth. Lastly, a gingivectomy may be enacted to extend the tooth and design a 1.5 mm sulcus if the probing depth of the sulcus is greater than 2 mm. **Take Home Message:** If you place a margin within 2mm of the crestal bone you will get inflammation, followed by bone loss as the biological width tries to re-establish itself ## **Margin Placement Guidelines** The margins of the restoration can be positioned 0.5 mm below the gingival tissue crest if the probing depth of the sulcus is 1.5 mm or less. > [!note] > These guidelines apply to **normal crest** patients. If the sulcus depth is more than 1.5mm, then the margins of the restoration should be inserted in the sulcus at a depth that is half its probing depth. Lastly, a gingivectomy may be enacted to extend the tooth and design a 1.5 mm sulcus if the probing depth of the sulcus is greater than 2 mm. > [!tip] > This must be weighed against aesthetic concerns, especially in the anterior region. **Normal Crest – Preparation & Tissue Management** Double cord Diagram showing five sequential steps of dental tissue management using a double cord technique. ## **Normal Crest – Preparation & Tissue Management** Double cord **Tissue Management** **Retraction cord** Clinical images showing gingival tissue management with retraction cord placement around a tooth. ## **Tissue Management** **Retraction cord** # Gingival Displacement ## Aims - Enlargement of gingival sulcus - Tissue deflection horizontally and vertically to display the margin and root surface - Finishing line for the restoration - Development of adequate emergence profile - Control of gingival bleeding and exudate # **Gingival Displacement** ## **Aims** - Enlargement of gingival sulcus - Tissue deflection horizontally and vertically to display the margin and root surface - Finishing line for the restoration - Development of adequate emergence profile - Control of gingival bleeding and exudate # Gingival Displacement ## Mechanical Displacement - Retraction cord - Copper band ## Chemicals Astringent: aluminium chloride, ferric sulfate Adrenaline - transient ischemia and epithelial tissue shrinkage ## Combined - Retraction cord + chemical - Expasyl (Kerr) ## Surgical widening - Electrosurgery - Laser # Gingival Displacement ## Mechanical Displacement - Retraction cord - Copper band ## Chemicals Astringent: aluminium chloride, ferric sulfate Adrenaline - transient ischemia and epithelial tissue shrinkage ## Combined - Retraction cord + chemical - Expasyl (Kerr) ## Surgical widening - Electrosurgery - Laser # Gingival Displacement ## Mechanical Displacement - Retraction cord - Copper band ## Chemicals Astringent: aluminium chloride, ferric sulfate Adrenaline - transient ischemia and epithelial tissue shrinkage ## Combined - Retraction cord + chemical - Expasyl (Kerr) ## Surgical widening - Electrosurgery - Laser # Gingival Displacement ## Mechanical Displacement - Retraction cord - Copper band ## Chemicals Astringent: aluminium chloride, ferric sulfate Adrenaline - transient ischemia and epithelial tissue shrinkage ## Combined - Retraction cord + chemical - Expasyl (Kerr) ## Surgical widening - Electrosurgery - Laser ## **Methods of Gingival Displacement** ### **Mechanical Displacement** - Retraction cord - Copper band ### **Chemicals** - Astringent: aluminium chloride, ferric sulfate - Adrenaline - transient ischemia and epithelial tissue shrinkage ### **Combined** - Retraction cord + chemical - Expasyl (Kerr) ### **Surgical widening** - Electrosurgery - Laser # Mechanical Displacement **Mechanical Displacement: Retraction cord** Cord is packed into sulcus stretching the circumferential periodontal fibers 0.3-0.4 mm **Types:** - Braided - Knitted - Twisted - Medicated and nonmedicated # **Mechanical Displacement** ## **Mechanical Displacement: Retraction cord** Cord is packed into sulcus stretching the circumferential periodontal fibers 0.3-0.4 mm ### **Types:** - Braided - Knitted - Twisted - Medicated and nonmedicated - ==Knitted cords (e.g., Ultrapak) are commonly used.== **Retraction Cord** Six bottles of ULTRAPAK retraction cord, each labeled with a different size and color-coded: #000 (black), #00 (orange), #0 (purple), #1 (blue), #2 (green), #3 (pink). ## **Retraction Cor Cords come in various sizes (e.g., 000, 00, 0, 1, 2) to suit different sulcus depths and tissue biotypes. d** **Cord Packer** Two images side-by-side: left shows serrated cord packers, right shows non-serrated cord packers. ## **Cord Pack A specialized instrument used to place the cord into the sulcus. - ==Can have a **serrated** or **non-serrated** tip. Serrated tips help grip the cord, but require a specific technique to avoid pulling the cord back out.== - ==A plastic instrument can also be used.== er** **Cord Packing technique** Diagram illustrating two methods of cord packing: Vertical and Rotational, showing dental tools and techniques for placing cord around a tooth. ## **Cord Packing technique** # Retraction cords **Fig 16-13** A loop of retraction cord is formed around the tooth and held tautly with the thumb and forefinger. **Fig 16-14** (a) Placement of the retraction cord is begun by pushing it into the sulcus on the mesial surface of the tooth. (b) It should also be tacked lightly into the distal crevice to hold the cord in position while it is being placed. Figure showing placement of retraction cord around a tooth, with detailed illustrations of the technique. ### **Technique Description** - **Fig 16-13** A loop of retraction cord is formed around the tooth and held tautly with the thumb and forefinger. - **Fig 16-14** (a) Placement of the retraction cord is begun by pushing it into the sulcus on the mesial surface of the tooth. (b) It should also be tacked lightly into the distal crevice to hold the cord in position while it is being placed. - ==The technique involves a **rotational, tucking motion**, not a straight up-and-down push.== - ==The instrument should be angled towards the tooth and slightly towards the already-packed portion of the cord.== - ==Cut a length of cord approximately **1.5 times the circumference** of the tooth to allow for overlap and proper packing.== - ==The ends of the cord should be left in an easily accessible area, such as the buccal or lingual surface, not interproximally.== **Mechanical Displacement: Retraction cord** Single cord Double cord Leave the cords in place three to five minutes ### **Cord Techniques** - Single cord - Double cord Leave the cords in place three to five minutes **Mechanical Displacement: Retraction cord** **Single cord** **Double cord** *1st cord: vertical retraction* *2nd cord: Horizontal displacement* GRACIS et al. 2001 ### **Single vs. Double Cord** - **Single cord** - **Double cord** - *1st cord: vertical retraction* - *2nd cord: Horizontal displacement* > [!tip] Double Cord Technique Explained > 1. ==A **thin cord (e.g., 000 or 00)** is placed first, deep into the sulcus and completely below the margin. This cord provides **vertical displacement** and remains in place during the impression.== > 2. ==A **larger cord (e.g., 0 or 1)** is packed on top of the first cord. This provides **horizontal displacement**.== > 3. ==The top cord is left in place for approximately **5 minutes** and then removed just before injecting the impression material.== GRACIS et al. 2001 **Mechanical Displacement: Retraction cord** **Single cord** **Indication:** - Shallow sulcus - Thin periodontium **Advantages:** - Least traumatic - Limited risk for gingival recession **Disadvantages:** - Haemorrhage - Exudate **Mechanical Displacement: Retraction cord** | Single cord | Double cord | | --- | --- | | **Indication:**<br>• Shallow sulcus<br>• Thin periodontium | Single cord | Double cord > [!info] > The goal is to retract the tissue to allow impression material to flow into the sulcus and capture the entire margin edge, providing the lab with a clear finish line. | | :--- | :--- | | **Indication:**<br>- Shallow sulcus<br>- Thin periodontium | | | **Advantages:**<br>- Least traumatic<br>- Limited risk for gingival recession | | | **Disadvantages:**<br>- Haemorrhage<br>- Exudate | | | **Indication:**<br>- Deeper sulcus<br>- When superior control of bleeding/fluid is needed | **Advantages:**<br>- Excellent lateral displacement<br>- Superior control of bleeding/fluid | **Disadvantages:**<br>- More time-consuming<br>- More traumatic to tissues<br>- Can lead to unpredictable gingival response in high or low crest patients **Chemical Displacement: Hemostatic agent** **Metallic salts** - Causing transient ischemia - Shrinkage of gingival tissues - Reduce flow of gingival fluids **Examples:** - Aluminum chloride (*Hemadent*) - Aluminum sulfate - Potassium sulfate - Ferric chloride - Ferric sulfate (*Astringedent*) **Adrenaline** - Can cause tachycardia # **Chemical Displacement: Hemostatic agent** ## **Metallic salts** - Causing transient ischemia - Shrinkage of gingival tissues - Reduce flow of gingival fluids ### **Examples:** - Aluminum chloride (*Hemadent*) - Aluminum sulfate - Potassium sulfate - Ferric chloride - Ferric sulfate (*Astringedent*) ## **Adrenaline** - Can cause tachycardia > [!danger] Caution > Use with care in patients with known sensitivity or cardiovascular disorders, as it can elevate blood pressure and heart rate, especially if applied to lacerated tissue. **Haemostasis - Expasyl** **Expasyl** Aluminium chloride with kaolin Dispensed from a syringe Expands on setting Left for 1-2 minutes Washed away with water spray **Traxodent** Aluminium chloride paste # **Haemostasis - Expasyl** - **Expasyl** - Aluminium chloride with kaolin - Dispensed from a syringe - Expands on setting - Left for 1-2 minutes - Washed away with water spray > [!info] > Expasyl provides both chemical and mechanical displacement. The **kaolin clay** in its composition expands as it sets, providing mechanical retraction. It can also be used in combination with a small retraction cord placed at the base of the sulcus. - **Traxodent** - Aluminium chloride paste **Expasyl** Dental impression material (Expasyl) applied around teeth, showing retraction and preparation for dental impressions. ## **Expasyl** **Expasyl** Dental impression with green retraction material around teeth and close-up of gingival margin with red arrows indicating retraction. ## **Expasyl** # Surgical Techniques - Remove the inner epithelial lining for better access to finish line, and control of haemorrhage - Risk of permanent damage - Recession - Avoid for thin gingiva ## Examples - Electrosurgery - Laser Diagrams and images illustrating surgical tools and devices, including electrosurgery and laser equipment. # **Surgical Techniques** - Remove the inner epithelial lining for better access to finish line, and control of haemorrhage - Risk of permanent damage - Recession - Avoid for thin gingiva - ==Can be used to cauterize bleeding areas to improve visibility.== ## **Examples** - Electrosurgery - Laser # Surgical Techniques ## Electrosurgery **Advantages:** - Lower cost than lasers. - Electrosurgery cuts rapidly when compared to a diode laser. - With proper intensity, immediate hemostasis. - After cutting, the wound is nearly painless. **Disadvantages:** - Contraindicated in patients with any electrical device (**PACEMAKERS!**) - You must anesthetize patients - Burning smell - Risk of overcutting - Because of high heat production while cutting, electrosurgery should not be used around implants ## **Electrosurgery** ### **Advantages:** - Lower cost than lasers. - Electrosurgery cuts rapidly when compared to a diode laser. - With proper intensity, immediate hemostasis. - After cutting, the wound is nearly painless. ### **Disadvantages:** - Contraindicated in patients with any electrical device (**PACEMAKERS!**) - You must anesthetize patients - Burning smell - Risk of overcutting - ==Because of high heat production while cutting, electrosurgery should not be used around implants== - Because of high heat production while cutting, electrosurgery should not be used around implants # Surgical Techniques **Laser** **Advantages:** - Minimal local anesthetic needed, - Does not harm dental hard tissue. - Can be used around implants (some laser produce heat) - Can be used around full metal, PFM crowns, amalgam or gold alloy restorations. **Disadvantages:** - Cost - Cuts much slower than electrosurgery. - Cutting large pieces of soft tissue is time consuming - Danger of laser beam ## **Laser** ### **Advantages:** - Minimal local anesthetic needed, - Does not harm dental hard tissue. - Can be used around implants (some laser produce heat) - Can be used around full metal, PFM crowns, amalgam or gold alloy restorations. ### **Disadvantages:** - Cost - Cuts much slower than electrosurgery. - Cutting large pieces of soft tissue is time consuming - Danger of laser beam - ==Requires special protective eyewear for the patient and clinical team.== # Saliva Control **Absorbents: block salivary ducts** - Cotton rolls - Absorbing cards **Saliva evacuator** **Local anesthesia: controls blood and saliva** # **Saliva Control** - **Absorbents: block salivary ducts** - Cotton rolls - ==Use cotton rolls to retract the tongue and cheeks.== - Absorbing cards - **Saliva evacuator** - **Local anesthesia: controls blood and saliva** # Impression Technique ## Impression timing - Inflamed gingivae are by definition swollen - Impossible to prepare a predictable intracrevicular margin - Impressions difficult due to uncontrolled haemorrhage - As soon as periodontal resolution occurs there will be recession - Therefore, achieve gingival health before embarking on definitive impressions 3-4 weeks with provisional restoration # **Impression Technique** ## **Impression timing** - Inflamed gingivae are by definition swollen - Impossible to prepare a predictable intracrevicular margin - Impressions difficult due to uncontrolled haemorrhage - As soon as periodontal resolution occurs there will be recession - Therefore, achieve gingival health before embarking on definitive impressions 3-4 weeks with provisional restoration > [!note] > If tissues are inflamed, swollen, or friable (bleed easily), it is best to place a well-fitting provisional and allow the tissues to heal for several weeks before re-appointing for the definitive impression. This avoids capturing a distorted tissue shape and prevents the final margin from being exposed after healing and recession. **Impression Materials** Materials for indirect restorations PVS – Poly Vinyl Siloxane Polyether # **Impression Materials** Materials for indirect restorations - PVS – Poly Vinyl Siloxane - Polyether # Impression Materials **Qualities** - Dimensional accuracy - Dimensional stability - Wettability - Contact Angle - Elastic recovery - Flexibility - Ease of handling - Tear Strength - Cost Table 17-1 Comparative properties of impression materials* # Impression Materials ## Dimensional accuracy: - Polyvinyl siloxane (PVS) and polyether impression materials remain dimensionally accurate for 1 to 2 weeks ## Hydrophilic vs Hydrophobic - Hydrophobic materials such as PVS may have voids if there is improper moisture control. - Polyether materials are hydrophilic and may better cope with the moisture in the oral environment ## **Qualities** - Dimensional accuracy - Dimensional stability - Wettability - Contact Angle - Elastic recovery - Flexibility - Ease of handling - Tear Strength - Cost ### **Dimensional accuracy:** - Polyvinyl siloxane (PVS) and polyether impression materials remain dimensionally accurate for 1 to 2 weeks ### **Hydrophilic vs Hydrophobic** - Hydrophobic materials such as PVS may have voids if there is improper moisture control. - Polyether materials are hydrophilic and may better cope with the moisture in the oral environment # Impression materials **Dimensional stability:** - “The dimensional stability of an impression material reflects its ability to maintain the accuracy of the impression over time” - Both polyether and PVS are dimensionally stable compared to alginates ### **Dimensional stability:** - “The dimensional stability of an impression material reflects its ability to maintain the accuracy of the impression over time” - Both polyether and PVS are dimensionally stable compared to alginates > [!warning] > Alginate is very unstable and must be poured immediately. # Impression materials **Wettability:** - “Wettability of an impression material relates to the ability of the material to flow into small areas” - Materials with a high wetting angle do not flow easily into small crevices and are poor candidates for use in fixed prosthodontics. Materials with a low wetting angle flow extensively. **Contact angle:** - “Impression materials with low contact angle enable dental stone to flow easily, and relatively bubble-free casts are produced. Materials with high contact angle require more careful pour technique and attention to produce accurate casts” ### **Wettability:** - “Wettability of an impression material relates to the ability of the material to flow into small areas” - Materials with a high wetting angle do not flow easily into small crevices and are poor candidates for use in fixed prosthodontics. Materials with a low wetting angle flow extensively. ### **Contact angle:** - “Impression materials with low contact angle enable dental stone to flow easily, and relatively bubble-free casts are produced. Materials with high contact angle require more careful pour technique and attention to produce accurate casts” # Impression materials **Elastic Recovery and Flexibility:** - Materials must distort to allow removal from undercuts - We want a material to have good elastic properties to allow recovery and minimise plastic deformation - PVS superior to polyether - Flexible materials are easier to remove from the mouth - There HAVE been cases of PVS impressions STUCK in a patient’s mouth. - Polyethers are EVEN MORE rigid - Alginate the least rigid. Stress-strain curve diagram showing proportionality limit, elastic limit, elastic behavior, plastic deformation, and fracture point ### **Elastic Recovery and Flexibility:** - Materials must distort to allow removal from undercuts - We want a material to have good elastic properties to allow recovery and minimise plastic deformation > [!info] > **Elastic Recovery** is the ability of the material to return to its original shape after being deformed during removal from undercuts. A high elastic limit is desired to prevent permanent (plastic) deformation. - PVS superior to polyether - Flexible materials are easier to remove from the mouth - There HAVE been cases of PVS impressions STUCK in a patient’s mouth. - Polyethers are EVEN MORE rigid - Alginate the least rigid. # Impression materials **Ease of handling:** - Prefer materials are that easy to work with in everyday clinical situations - Thixotrophy ### **Ease of handling:** - Prefer materials are that easy to work with in everyday clinical situations - Thixotrophy > [!info] > **Thixotropy** is a desirable property where the material becomes more fluid when sheared (e.g., injected from a syringe) but remains viscous enough not to slump off the tray. **Impression materials** Tear strength: - “The tear strength of an impression material relates to how resistant a particular material is to tearing after setting” ### **Tear strength:** - “The tear strength of an impression material relates to how resistant a particular material is to tearing after setting” > [!note] > Polyether has a very high tear strength, PVS is moderate, and alginate is very low. **Dental materials** In order of history: - Reversible hydrocolloid (Alginate is irreversible hydrocolloid) - Polysulfides - Condensation silicon - **Polyether** - **Addition silicon** ## **Types of Dental Materials (Historical Order)** - Reversible hydrocolloid (Alginate is irreversible hydrocolloid) - Polysulfides - Condensation silicon - **Polyether** - **Addition silicon** # Reversible hydrocolloids - Eg. Agar which is able to be melted to a gel like consistency, then cooled to form a more solid material - Requires special materials to prepare for the impression as well as a tray capable of cooling the agar to “set” it - Excellent dimensional accuracy if poured immediately Hydrocolloid conditioning equipment and impression technique steps (A-F) showing material preparation, tray loading, intraoral placement, and setting process. ### **Reversible hydrocolloids** - Eg. Agar which is able to be melted to a gel like consistency, then cooled to form a more solid material - Requires special materials to prepare for the impression as well as a tray capable of cooling the agar to “set” it - Excellent dimensional accuracy if poured immediately **Irreversible hydrocolloids** - Alginate powder consists of calcium sulfate dehydrate, soluble alginate, and sodium phosphate - Setting of alginate: Calcium ions from the calcium sulfate dehydrate react preferentially with phosphate ions from the sodium phosphate (retarder to slow setting and increase working time). After the phosphate ions are depleted, the calcium ions react with the soluble alginate to form insoluble calcium alginate, which with water forms the irreversible calcium alginate gel. - Moderate dimensional accuracy but very poor dimensional stability - Low tear strength ### **Irreversible hydrocolloids** - Alginate powder consists of calcium sulfate dehydrate, soluble alginate, and sodium phosphate - Setting of alginate: Calcium ions from the calcium sulfate dehydrate react preferentially with phosphate ions from the sodium phosphate (retarder to slow setting and increase working time). After the phosphate ions are depleted, the calcium ions react with the soluble alginate to form insoluble calcium alginate, which with water forms the irreversible calcium alginate gel. - Moderate dimensional accuracy but very poor dimensional stability - Low tear strength # Polysulfides - Supplied as a 2 paste system: - Base: polysulfide polymer (terminal/side chain −SH groups), titanium dioxide, zinc sulfate, copper carbonate, or silica. - Accelerator (catalyst): lead dioxide with other substances, such as dibutyl or dioctyl phthalate, sulfur, and magnesium stearate and deodorants. - Sets by oxidation of the −SH groups, which results in chain lengthening and cross-linking and gives it elastomeric properties. - Better tear strength compared to hydrocolloids - Low to moderately hydrophilic, so could work in low blood/saliva environments - However unpleasant odor and long set time (~10mins) ### **Polysulfides** - Supplied as a 2 paste system: - **Base:** polysulfide polymer (terminal/side chain −SH groups), titanium dioxide, zinc sulfate, copper carbonate, or silica. - **Accelerator (catalyst):** lead dioxide with other substances, such as dibutyl or dioctyl phthalate, sulfur, and magnesium stearate and deodorants. - Sets by oxidation of the −SH groups, which results in chain lengthening and cross-linking and gives it elastomeric properties. - Better tear strength compared to hydrocolloids - Low to moderately hydrophilic, so could work in low blood/saliva environments - However unpleasant odor and long set time (~10mins) **Condensation silicons** - Improvement over polysulfides as it is mostly odourless - Greater dimensional stability compared to hydrocolloids but not as great as polysulfides - As a condensation silicon, water is released as a by product. This can cause dimensional accuracy/stability issues from evaporation - Very hydrophobic ### **Condensation silicons** - Improvement over polysulfides as it is mostly odourless - Greater dimensional stability compared to hydrocolloids but not as great as polysulfides - As a condensation silicon, water is released as a by product. This can cause dimensional accuracy/stability issues from evaporation - Very hydrophobic **Polyether** - Polyethers also consist of a base and catalyst system: - Base: long-chain polyether copolymer with alternating oxygen atoms and methylene groups (O-[CH₂]ₙ) and reactive terminal groups. - Catalyst paste has a cross-linking agent (aliphatic cationic starter) and filler and plasticizers. Polyethers involve the reaction of the polyether-containing imine ringed side chains with a reactant that opens the rings and causes chain lengthening and cross-linking to form a polyether rubber. - Acceptable setting time of ~5 minutes - High tear strength, however material is extremely stiff, hence can be difficult to remove from areas of undercuts. - Can be poured 1-2 weeks after impression from excellent dimensional stability - Potential allergy/sensitivity issues ### **Polyether** - Polyethers also consist of a base and catalyst system: - **Base:** long-chain polyether copolymer with alternating oxygen atoms and methylene groups (O-[CH₂]ₙ) and reactive terminal groups. - **Catalyst paste** has a cross-linking agent (aliphatic cationic starter) and filler and plasticizers. Polyethers involve the reaction of the polyether-containing imine ringed side chains with a reactant that opens the rings and causes chain lengthening and cross-linking to form a polyether rubber. - Acceptable setting time of ~5 minutes - High tear strength, however material is extremely stiff, hence can be difficult to remove from areas of undercuts. - Can be poured 1-2 weeks after impression from excellent dimensional stability - Potential allergy/sensitivity issues **PVS** - Very popular material for impressions - Setting: linking of vinyl siloxane in the base material with a hydrogen siloxane via a platinum catalyst - Polyvinyl siloxanes have improved dimensional accuracy compared to condensation silicones. - Due to by product of hydrogen gas instead of water. Newer products have “Scavengers” that prevent the escape of gas at the polymer-stone interface. - Stiffness less than polyether allows easier removal from mouth - Latex gloves (Sulphur compounds) may inhibit set. - Moderately high contact angle, so sometimes surfactant sprays used to encourage flow of stone during pouring. ### **PVS** - Very popular material for impressions - **Setting:** linking of vinyl siloxane in the base material with a hydrogen siloxane via a platinum catalyst - Polyvinyl siloxanes have improved dimensional accuracy compared to condensation silicones. - Due to by product of hydrogen gas instead of water. Newer products have “Scavengers” that prevent the escape of gas at the polymer-stone interface. - Stiffness less than polyether allows easier removal from mouth - Latex gloves (Sulphur compounds) may inhibit set. - Moderately high contact angle, so sometimes surfactant sprays used to encourage flow of stone during pouring. # Impression Techniques **Single stage** **Two Stage** Spacer or No Spacer Impression Techniques slide showing three dental impressions labeled Single stage, Two Stage, and Spacer or No Spacer. # **Impression Techniques** - **Single stage** - **Two Stage** - Spacer or No Spacer **Monophase** preparation with retraction cord preparation covered with impression material tray inserted with the same impression material **NOT RECOMMENDED DUE TO LOWER DEFINITION** ## **Monophase** - preparation with retraction cord - preparation covered with impression material - tray inserted with the same impression material **NOT RECOMMENDED DUE TO LOWER DEFINITION** **Dualphase – Lightbody & Heavybody** Three-step dental impression process: 1. Tooth preparation with retraction cord. 2. Preparation covered with lightbody (LB) material. 3. Tray inserted with heavy body (HB) material. ## **Dualphase – Lightbody & Heavybody This is the **recommended single-stage technique**. - ==**Light body** (low viscosity) is syringed around the preparation to capture fine detail.== - ==**Heavy body** (high viscosity) is loaded into the tray to provide support and pressure.== - ==The two materials bond and set together in the mouth.== ** # Dualphase – “Putty Wash” **preparation with retraction cord** **preparation covered with lightbody (LB) material** **tray inserted with putty material** One-step putty impressions can have significantly lower accuracy compared to two step impressions ## **Dualphase – “Putty Wash”** - **preparation with retraction cord** - **preparation covered with lightbody (LB) material** - **tray inserted with putty material** One-step putty impressions can have significantly lower accuracy compared to two step impressions **Two-step impression with Putty** preparation with retraction cord Impression with putty Putty cut-out Preparation / putty cut-out covered with lightbody (LB) Good accuracy ## **Two-step impression with Putty** - preparation with retraction cord - Impression with putty - Putty cut-out > [!tip] > Space is created for the wash material, either by cutting away some putty around the prep or by using a plastic spacer during the initial impression. - Preparation / putty cut-out covered with lightbody (LB) - Good accuracy **1-stage vs 2-stage** - Significant differences seen on some surfaces of the impressions - However both impression techniques are clinically acceptable (marginal gap <120um) **FIGURE 1:** Comparison of the means of marginal gaps for one- and two-stage impression techniques. **Research Article** *Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis* Ladan Jamshidy,¹ Hamid Reza Mozaffari,² Payam Faraji,³ and Roohollah Sharifi⁴ Bar chart comparing marginal gap means for one- and two-stage impression techniques across buccal, distal, lingual, mesial, and total surfaces. ## **1-stage vs 2-stage** - Significant differences seen on some surfaces of the impressions - However both impression techniques are clinically acceptable (marginal gap <120um) **FIGURE 1:** Comparison of the means of marginal gaps for one- and two-stage impression techniques. **Research Article** *Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis* Ladan Jamshidy,¹ Hamid Reza Mozaffari,² Payam Faraji,³ and Roohollah Sharifi⁴ # Clinical steps ## Intraoral custom tray try-in - Check for clearance & comfort - Adjust if required - Tray adhesive application - Adhesive must be applied 15 minutes prior to impression - Extend the adhesive over edge of tray to the outer surface of the tray ## Gingival displacement - Isolate prepared teeth (free from saliva and blood) - Cut sufficient cord length - Wet the cord in astringent - Loop the cord around the tooth and gently insert it in the sulcus - Avoid overpacking - Dry the teeth (do not desiccate) - Evaluation - Visualize all the margins of the preparation - No soft tissue folding over the cord # Clinical steps ## Intraoral custom tray try-in - Check for clearance & comfort - Adjust if required - Tray adhesive application - Adhesive must be applied 15 minutes prior to impression - Extend the adhesive over edge of tray to the outer surface of the tray ## Gingival displacement - Isolate prepared teeth (free from saliva and blood) - Cut sufficient cord length - Wet the cord in astringent - Loop the cord around the tooth and gently insert it in the sulcus - Avoid overpacking - Dry the teeth (do not desiccate) - Evaluation - Visualize all the margins of the preparation - No soft tissue folding over the cord # **Clinical steps** ## **Intraoral custom tray try-in** - Check for clearance & comfort - Adjust if required - Tray adhesive application - Adhesive must be applied 15 minutes prior to impression - Extend the adhesive over edge of tray to the outer surface of the tray > [!tip] > The adhesive should be allowed to dry for approximately 15 minutes until it is tacky to ensure the impression material does not separate from the tray upon removal. ## **Gingival displacement** - Isolate prepared teeth (free from saliva and blood) - Cut sufficient cord length - Wet the cord in astringent - Loop the cord around the tooth and gently insert it in the sulcus - Avoid overpacking - Dry the teeth (do not desiccate) - Evaluation - Visualize all the margins of the preparation - No soft tissue folding over the cord # Clinical Steps **Impression material mixing:** If using “cartridge” system, - Extrude a little impression material first - Ensures an even mix of material & no blockage in the cartridge If using Putty (addition silicon): - Latex gloves may inhibit setting - Equal amount of base and catalyst ## **Impression material mixing:** - If using “cartridge” system, - Extrude a little impression material first > [!info] > This ensures an even mix of base and catalyst and confirms there is no blockage in the cartridge. - Ensures an even mix of material & no blockage in the cartridge - If using Putty (addition silicon): - Latex gloves may inhibit setting - Equal amount of base and catalyst **Clinical Steps** Loading the tray: - Clinician to apply light body material on the tooth whilst an assistant loads the medium/heavy body in the tray. - Load adequate amount of material in the tray (just below the height of the tray) - Do not lift the tip of impression material cartridge out from the loaded material - Be mindful of total setting time Two images showing impression material being loaded into a dental tray and a gloved hand holding a loaded tray. ## **Loading the tray:** - Clinician to apply light body material on the tooth whilst an assistant loads the medium/heavy body in the tray. - Load adequate amount of material in the tray (just below the height of the tray) - Do not lift the tip of impression material cartridge out from the loaded material > [!tip] > Keep the mixing tip submerged in the material to avoid incorporating air bubbles. - Be mindful of total setting time **Clinical Steps** Intra-oral material application: - Remove second cord in double cord retraction technique, rinse off expasyl - Adequately dry the preparation, ensure good isolation (tongue etc) - Inject material around tooth - Start from the hardest area (likely interproximals) - Do not lift tip from impression material - Inject on top of the margins/sulcus areas - One direction - Cover the entire prep and part of the adjacent teeth - Optional: Air thin the material with triplex ## **Intra-oral material application:** - Remove second cord in double cord retraction technique, rinse off expasyl - Adequately dry the preparation, ensure good isolation (tongue etc) - Inject material around tooth - Start from the hardest area (likely interproximals) - Do not lift tip from impression material > [!tip] > **Keep the tip of the syringe submerged in the material** and move in one continuous direction around the preparation to prevent bubbles. - Inject on top of the margins/sulcus areas - One direction - Cover the entire prep and part of the adjacent teeth - Optional: Air thin the material with triplex **Tray insertion** - Position tray into correct position in mouth first - Clear lips from tray - Using one continuous and slow seating movement of the tray into correct area ## **Tray insertion** - Position tray into correct position in mouth first - Clear lips from tray - Using one continuous and slow seating movement of the tray into correct area > [!tip] > Seat the tray with a **slow, continuous movement from back to front**. This directs excess material forward, away from the patient's throat. Hold the tray steady for the full manufacturer-recommended setting time (e.g., 5 minutes). # Tray removal - Hold tray in mouth until impression is set - Optimum removal of impression tray: - upper jaw - loosen tray on opposing side - lower jaw - loosen tray on prep side. - front teeth - both sides at the same time. *A guideline for excellent impressions in theory and practice - 3M* # **Tray removal** - Hold tray in mouth until impression is set - Optimum removal of impression tray: - upper jaw - loosen tray on opposing side - lower jaw - loosen tray on prep side. - front teeth - both sides at the same time. *A guideline for excellent impressions in theory and practice - 3M* # Impression Technique ## Impression inspection - **Detailed, accurate occlusal surfaces** *Cusps are sharp* *Tray doesn't show through* - **Distal surfaces of molars are captured** *More than half of each molar is visible* - **No bubbles, voids, thin walls, shifts, or double imprints that compromise dental anatomy** - **All gingival margins are defined & clear** *Includes at least 3–4 mm of buccal & lingual surfaces outside gingival margin* - **Uniform layer of material** *Impression material is intact* *No damage, warping, or separation of light & heavy material* # **Impression Inspection** - **Detailed, accurate occlusal surfaces** - *Cusps are sharp* - *Tray doesn't show through* - **Distal surfaces of molars are captured** - *More than half of each molar is visible* - **No bubbles, voids, thin walls, shifts, or double imprints that compromise dental anatomy** - **All gingival margins are defined & clear** - *Includes at least 3–4 mm of buccal & lingual surfaces outside gingival margin* - **Uniform layer of material** - *Impression material is intact* - *No damage, warping, or separation of light & heavy material* > [!quote] > If you, the clinician, cannot clearly identify the margin on the impression, the lab will not be able to either. **Gagging Patients?** - Explain procedure (esp. if likely to gag) - Use special tray & less material (don’t apply material on the palate for fixed pros) - Have suction and mouth mirror ready to remove excess from posterior border - Sit patient up - Do not remove once seated even if you think unsatisfactory - Reassure patient # **Gagging Patients?** - Explain procedure (esp. if likely to gag) - Use special tray & less material (don’t apply material on the palate for fixed pros) - Have suction and mouth mirror ready to remove excess from posterior border - Sit patient up - ==Instruct them to lean forward to prevent material from flowing down their throat.== - ==Reassure them but explain that the tray cannot be removed until it is fully set.== - Do not remove once seated even if you think unsatisfactory - Reassure patient **Trouble Shooting** - Bubbles - Drag lines - Marginal Tears - Incomplete set **Trouble Shooting** - Bubbles - Drag lines - Marginal Tears - Incomplete set # **Trouble Shooting** - Bubbles - ==**Cause:** Moisture/blood contamination or incorporating air during material application.== - ==**Solution:** Ensure a dry field with good hemostasis. Keep the syringe tip submerged in the material during application.== - Drag lines - ==**Cause:** The material began to set before the tray was fully seated, or the tray moved during setting. This indicates you are not working fast enough.== - ==**Solution:** Improve workflow efficiency. Have all materials ready to go.== - Marginal Tears - **Incomplete set** - ==**Cause:** Removing the impression too soon before it was fully set; contamination with latex/sulfur; or an incorrect mix ratio from a blocked cartridge.== - ==**Solution:** Time the set accurately. Use nitrile gloves. Bleed the cartridge before use.== - Incomplete set **Triple Trays** Allows for registration of the upper and lower arch simultaneously. However not recommended due to distortion of material Triple Trays with blue material and green handle, showing upper and lower arch impressions, alongside a mesh tool labeled "Mesh". # **Triple Trays** Allows for registration of the upper and lower arch simultaneously. However not recommended due to distortion of material > [!note] > They may have limited use in specific situations, such as for a single crown when a patient has very limited opening. **Thanks for listening** Please remember this lecture essentially takes the spot of the “Materials for Indirect Coronal Restorations”. Occlusion lecture to be arranged when Dr Matsubara is available # **Thanks for listening** Please remember this lecture essentially takes the spot of the “Materials for Indirect Coronal Restorations”. Occlusion lecture to be arranged when Dr Matsubara is available [[F6 ImpressionsSoftTissue.pdf#page=1|F6 ImpressionsSoftTissue, p.1]] [[F6 ImpressionsSoftTissue.pdf#page=2|F6 ImpressionsSoftTissue, p.2]] [[F6 ImpressionsSoftTissue.pdf#page=3|F6 ImpressionsSoftTissue, p.3]] [[F6 ImpressionsSoftTissue.pdf#page=4|F6 ImpressionsSoftTissue, p.4]] [[F6 ImpressionsSoftTissue.pdf#page=5|F6 ImpressionsSoftTissue, p.5]] [[F6 ImpressionsSoftTissue.pdf#page=6|F6 ImpressionsSoftTissue, p.6]] [[F6 ImpressionsSoftTissue.pdf#page=7|F6 ImpressionsSoftTissue, p.7]] [[F6 ImpressionsSoftTissue.pdf#page=8|F6 ImpressionsSoftTissue, p.8]] [[F6 ImpressionsSoftTissue.pdf#page=9|F6 ImpressionsSoftTissue, p.9]] [[F6 ImpressionsSoftTissue.pdf#page=10|F6 ImpressionsSoftTissue, p.10]] [[F6 ImpressionsSoftTissue.pdf#page=11|F6 ImpressionsSoftTissue, p.11]] [[F6 ImpressionsSoftTissue.pdf#page=12|F6 ImpressionsSoftTissue, p.12]] [[F6 ImpressionsSoftTissue.pdf#page=13|F6 ImpressionsSoftTissue, p.13]] [[F6 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