Lecture 11: Clinical Steps **The University of Western Australia** By Dr Cheryl Fu Based on slides by Dr Matsubara Lecture 11: Clinical Steps By Dr Cheryl Fu Based on slides by Dr Matsubara **Questions:Occlusion** The University of Western Australia **ACP AMERICAN COLLEGE OF PROSTHODONTISTS** *Your smile. Our specialty.* **The Relationship Between Centric Occlusion and The Maximal Intercuspal Position and Their Use as Treatment Positions for Complete Mouth Rehabilitation: Best Evidence Consensus Statement** Mathew T. Kattadiyil, BDS, MDS, MS¹, Abdualaziz A. Alzaid, BDS, MS,²,³ & Stephen D. Campbell, DDS, MMSc⁴ **Abstract** **Purpose:** The purpose of this Best Evidence Consensus Statement was to evaluate the existing literature relative to two focus questions: How often does centric occlusion coincide with maximal intercuspal position in dentate and partially dentate populations?; and should centric occlusion or maximal intercuspal positions be equivalent for dentate and partially dentate patients undergoing complete mouth rehabilitation? **Materials and Methods:** Keywords used in the initial search were: intercuspal position, centric occlusion, centric relation, maximal intercuspal position, prosthodontic rehabilitation, and occlusion. The search was then limited to Systematic Reviews, Randomized Controlled Studies, Meta-Analyses and Clinical Trials. **Results:** The initial search strategy related to the selected search terms resulted in more than 15,000 articles. When the subsequent search was limited to Systematic Reviews, Randomized Controlled Studies, and Meta-Analysis and Clinical Trials, 313 articles were selected for further analysis. **Conclusions:** Review of the literature reveals that most dentate and partially dentate patients do not have coincident centric occlusion and maximal intercuspal position. There is support for coincidence between centric occlusion and maximal intercuspal position as the preferred occlusal relationship in complete mouth rehabilitations. The literature does not report conclusive evidence of adverse prosthodontic outcomes with complete rehabilitations in centric occlusion or maximal intercuspal position in a healthy population. However, there is support for an association between centric occlusion-maximal intercuspal position discrepancies and occlusal instability **as well as temporomandibular joint disorders**. Hence, it is concluded that partially and completely dentate patients requiring complete mouth rehabilitation should be restored in centric occlusion. The Glossary of Prosthodontics Terms¹ defines centric relation as the maxillomandibular relationship, independent of tooth contact, in which the condyles articulate in the anterior-superior position against the posterior slopes of the articular eminences; in this position, the mandible is restricted to a purely rotary movement; from this unstrained, physiologic, maxillomandibular relationship, the patient can make vertical, lateral or protrusive movements; it is a clinically useful, repeatable reference position. **Centric occlusion** is defined as the occlusion of opposing teeth when the mandible is in centric relation; this may or may not coincide with the **maximal intercuspal position.¹** **Maximal intercuspal position** is defined as the complete intercuspation of the opposing teeth independent of condylar position, sometimes referred to as the best fit of the teeth regardless of the condylar position.¹ The purpose of this Best Evidence Consensus Statement is to review the literature to answer two focus questions related to CR, CO, and MIP. #### Best Evidence Consensus Statement: Treatment Positions for Complete Mouth Rehabilitation **Purpose and Methodology** This consensus statement evaluated the relationship between Centric Occlusion (CO) and Maximal Intercuspal Position (MIP) to determine their roles in complete mouth rehabilitation. The study analyzed 313 relevant articles, including systematic reviews and clinical trials, from an initial search of over 15,000 records. **Key Findings and Conclusions** - **Coincidence of CO and MIP:** In most dentate and partially dentate patients, CO and MIP do not coincide. - **Clinical Recommendation:** For patients requiring complete mouth rehabilitation, restoring the patient in centric occlusion is supported as the preferred relationship. - **Clinical Risks:** Discrepancies between CO and MIP are associated with occlusal instability and temporomandibular joint (TMJ) disorders. - **Safety:** There is no conclusive evidence of adverse outcomes when rehabilitating in either CO or MIP in healthy populations. #### Standardized Definitions - **Centric Relation (CR):** A maxillomandibular relationship, independent of tooth contact, where the condyles articulate in the anterior-superior position against the posterior slopes of the articular eminences. It is a repeatable, purely rotary reference position. - **Centric Occlusion (CO):** The occlusion of opposing teeth when the mandible is in centric relation. This may or may not coincide with the maximal intercuspal position. - **Maximal Intercuspal Position (MIP):** The complete intercuspation of opposing teeth independent of condylar position (the "best fit" of teeth). # Questions: Occlusion ## Google’s definition Centric occlusion refers to **a position of maximal, bilateral, balanced contact between the cusps of the maxillary and mandibular arches**. Centric relation is the most retruded, unstrained position of the mandibular condyle within the temporomandibular joint (TMJ), that is, within the glenoid fossa. A three-dimensional comparison of condylar change between centric relation and centric occlusion using mandibular position indicator Donald J. Rinchuse DMD, MS, MDS, PhD “CR has always been a “condylar position,” whereas CO has always been an interocclusal position. Therefore CR is not a comparable term to CO, because the former denotes condyle position and the latter denotes an interocclusal dental position” --- Third edition (1968); page 452 **Centric Jaw Relation—(1)** The most retruded physiologic relation of the mandible to the maxilla to and from which the individual can make lateral movements. It is a condition which can exist at various degrees of jaw separation. It occurs around the terminal hing axis. **(2)** The most posterior relation of the mandible to the maxilla at the established vertical relation. **Centric Occlusion**—The **centered contact position** of the **lower occlusal surfaces against the upper ones**; a **reference position** from which all other horizontal positions are eccentric. Fifth edition (1987); pages 724-725 **Centric Occlusion**—The **occlusion of opposing teeth when the mandible is in centric relation**. This may or may not coincide with the maximum intercuspation position. This is a term in transition to obsolescence. (See also *intercuspaton, maximum*.) **Centric Relation**—A maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective disks with the complex in the anterior-superior position against the slopes of the articular eminences. This position is independent of tooth contact. This position is clinically discernible when the mandible is directed superiorly and anteriorly and restricted to a purely rotary movement about a transverse horizontal axis. This term is in transition to obsolescence. #### Comparative Definitions and Historical Perspectives **General Definitions** - **Centric Occlusion:** A position of maximal, bilateral, balanced contact between the cusps of the maxillary and mandibular arches. - **Centric Relation:** The most retruded, unstrained position of the mandibular condyle within the glenoid fossa of the temporomandibular joint. **Condylar vs. Interocclusal Positions** According to Donald J. Rinchuse, CR and CO are not directly comparable terms because: - **CR** denotes a condylar position. - **CO** denotes an interocclusal dental position. #### Evolution of Terms (Glossary of Prosthodontic Terms) **Third Edition (1968)** - **Centric Jaw Relation:** The most retruded physiologic relation of the mandible to the maxilla from which lateral movements can be made; occurs around the terminal hinge axis. - **Centric Occlusion:** The centered contact position of the lower occlusal surfaces against the upper ones; the reference position for all eccentric horizontal positions. **Fifth Edition (1987)** - **Centric Occlusion:** The occlusion of opposing teeth when the mandible is in centric relation. Noted as a "term in transition to obsolescence." - **Centric Relation:** A relationship where condyles articulate with the thinnest avascular portion of their disks in an anterior-superior position. Discernible when the mandible is restricted to purely rotary movement about a transverse horizontal axis. # Questions: Posselts envelope Fig. 3. Posselt's envelope of motion in the sagittal plane at terminal hinge movement ($H$): (1) the retruded contact position; (2) the intercuspal position; (3) the edge-to-edge occlusion; (4) anterior biting to a reversed vertical overlap; (5) the protruded contact position; ($II$) transition from the posterior terminal hinge to a further open posterior position; ($III$) maximal opening; and ($O$) a line parallel to the occlusal plane. | CO | Centric Occlusion | | :--- | :--- | | **CR** | Centric Relation | | **THA** | Terminal Hinge Axis | | **RAT** | Rotation | | **MMO** | Maximum Mouth Opening | | **MRL** | Mid-Retrusive Line | | **ER** | Early Rotational | | **MP** | Maximum Protrusion | | **MLL** | Mid-Lateral Line | **A (Sagittal View)** * **RCP** - Retruded Contact Position * **ICP** - Intercuspal Position * **MP** - Maximum Protrusion * **PP** - Protrusive Position * **E** - Edge-to-edge * **MRO** - Maximum Retrusive Opening * **MTO** - Maximum Terminal Opening **B (Frontal View)** * **RLP** - Right Lateral Protrusion * **LLP** - Left Lateral Protrusion * **ICP** - Intercuspal Position * **PP** - Protrusive Position * **MTO** - Maximum Terminal Opening **C (Horizontal View)** * **RCP** - Retruded Contact Position * **PP** - Protrusive Position * **RLP** - Right Lateral Protrusion * **LLP** - Left Lateral Protrusion * **MP** - Maximum Protrusion **Large Diagram Labels** * **B** - Biting edge * **CR** - Centric Relation * **CO** - Centric Occlusion * **F** - Forward/Protruded position * **E** - Maximum extension/opening * **Incisor point** * **Mandibular** * **$L_{max}$** - Maximum length/opening height     #### Sagittal Plane Components (Posselt's Envelope) 1. **Retruded Contact Position (RCP):** The initial tooth contact during terminal hinge movement. 2. **Intercuspal Position (ICP):** The position of maximum tooth interdigitation. 3. **Edge-to-Edge Occlusion:** Contact between the incisal edges of anterior teeth. 4. **Anterior Biting:** Movement to a reversed vertical overlap. 5. **Protruded Contact Position:** The most forward contact position. 6. **Transition Phase (II):** Movement from the posterior terminal hinge to further opening. 7. **Maximal Opening (III):** The point of greatest mandibular descent. #### Terminology and Abbreviations - **CO:** Centric Occlusion - **CR:** Centric Relation - **THA:** Terminal Hinge Axis - **RAT:** Rotation - **MMO:** Maximum Mouth Opening - **MRL:** Mid-Retrusive Line - **ER:** Early Rotational - **MP:** Maximum Protrusion - **MLL:** Mid-Lateral Line #### View-Specific Reference Points **A. Sagittal View** - **RCP:** Retruded Contact Position - **ICP:** Intercuspal Position - **MP:** Maximum Protrusion - **PP:** Protrusive Position - **E:** Edge-to-edge - **MRO:** Maximum Retrusive Opening - **MTO:** Maximum Terminal Opening **B. Frontal View** - **RLP:** Right Lateral Protrusion - **LLP:** Left Lateral Protrusion - **ICP:** Intercuspal Position - **PP:** Protrusive Position - **MTO:** Maximum Terminal Opening **C. Horizontal View** - **RCP:** Retruded Contact Position - **PP:** Protrusive Position - **RLP:** Right Lateral Protrusion - **LLP:** Left Lateral Protrusion - **MP:** Maximum Protrusion **Diagram Labels** - **B:** Biting edge - **F:** Forward/Protruded position - **E:** Maximum extension/opening - **Lmax:** Maximum length/opening height Fig. 3: Posselt's envelope of motion in the sagittal plane at terminal hinge movement (H). The diagram shows a grid with labeled points 1-5 and regions II and III. Labels include H (terminal hinge), CO (centric occlusion), CR (centric relation), MRL (mid-retrusive line), ER (early rotation), MP (maximum protrusion), MLL (mid-lateral line), THA (terminal hinge axis), RAT (rotation), MMO (maximum mouth opening). Posselt's envelope diagram showing mandibular movements in the sagittal plane. Key labels include CO (centric occlusion), CR (centric relation), THA (terminal hinge axis), RAT (rotation), MMO (maximum mouth opening), MRL (mid-retrusive line), ER (early rotation), MP (maximum protrusion), and MLL (mid-lateral line). Curved lines represent different paths of mandibular movement. Three views of Posselt's envelope: A (Sagittal View) showing RCP, ICP, MP, PP, E, MRO, MTO; B (Frontal View) showing RLP, LLP, ICP, PP, MTO; C (Horizontal View) showing RCP, PP, RLP, LLP, MP. Each view is labeled with specific jaw positions and movements. Large diagram illustrating mandibular movement with labels: B (biting edge), CR (centric relation), CO (centric occlusion), F (forward/protruded position), E (maximum extension/opening), Incisor point, Mandibular, L_max (maximum length/opening height). Shows the path from centric relation to maximum opening. Questions: Posselets Envelope THE UNIVERSITY OF WESTERN AUSTRALIA PLEASE UPDATE TO: **Retruded contact** **position/Maximum** **intercuspal position/** **Centric** **Relation** **Centric** **Occlusion** **Maximum** **Protrusion** **Edge to Edge** **True Hinge** **Axis** **Rotation** **Translation/** **Gliding** **Maximal** **Opening**  #### Key Mandibular Positions and Movements - Retruded contact position - Maximum intercuspal position - Centric Relation - Centric Occlusion - Maximum Protrusion - Edge to Edge - True Hinge Axis - Rotation - Translation / Gliding - Maximal Opening Labeled kinematic diagram of the mandibular movement envelope (Posselets Envelope). The visual shows a curved path connecting key occlusal positions including Retruded contact position/Maximum intercuspal position/Centric Relation, Centric Occlusion, Maximum Protrusion, Edge to Edge, True Hinge Axis Rotation, Translation/Gliding, and Maximal Opening. Red annotations highlight specific regions such as 'Centric Occlusion' and the relationship between centric relations and maximum intercuspal position. - **The “big picture” of indirect restorations** - Clinical steps for treatment planning, preparation stage and insert - Assessing the permanent crown No reading for this lecture!  #### Overview of Indirect Restorations - The "big picture" of indirect restorations - Clinical steps for treatment planning, preparation stage, and insertion - Assessing the permanent crown No reading for this lecture! University of Western Australia logo featuring a shield with two swans and the university name in blue text. # The “big picture” ```mermaid graph LR A[Clinical examination] --> B[Primary Impression] B --> C["Tooth preparation + Temporisation"] C --> D[Definitive Impression] C --> E[Intraoral scanning] D --> F["Wax up (gold crown, PFM)"] E --> G[CAD All-ceramic] G --> H[Milling] H --> I[Try-in] F --> I I --> J[Cementation] J --> K[Review] ```         #### The "Big Picture" Clinical Workflow 1. **Clinical Examination** 2. **Primary Impression** 3. **Tooth Preparation + Temporisation** 4. **Impression Phase** - Definitive Impression (leading to Wax up for gold crown or PFM) - Intraoral Scanning (leading to CAD All-ceramic and Milling) 5. **Try-in** 6. **Cementation** 7. **Review** Clinical photo of a dental articulator setup with a cast mounted on it, illustrating the 'Primary Impression' step in the workflow. Clinical photo showing a tooth preparation procedure with an instrument being used on a prepared tooth, labeled as part of 'Tooth preparation + Temporisation'. Photo of a milled ceramic crown attached to a temporary abutment or fixture, representing the 'Milling' stage. Close-up clinical photo showing the internal structure of a metal-ceramic (PFM) crown, likely illustrating the 'Casting and veneering' process. Digital rendering/photo of a wax-up model on a stone cast, demonstrating the 'Wax up' step for gold crown or PFM fabrication. Digital image of blue wax patterns on a stone cast, illustrating the 'Wax up' phase before casting. Intraoral clinical photo showing teeth with provisional restorations or cementation materials, corresponding to the 'Cementation' step. Studio photo of a completed all-ceramic crown, likely used to illustrate the final product after 'Try-in'. **Treatment planning** Assessing the tooth (+assessing all the dentition and the patient) Assessing the tooth, the entire dentition, and the patient as part of the comprehensive treatment planning process. # Treatment planning ## Assessing the tooth (+assessing all the dentition and the patient) ### Why Does a Tooth Need a Crown? **Considerations for a crown:** - **Destruction of tooth structure** - **Aesthetics** - **Plaque Control/Moisture Control** - **Retention** Fig 6-1 A comparison of resistance to removal forces for four types of crowns (P = .05).<sup>1,2</sup> MOD, mesio-occlusodistal; Figure credit: <i>Fundamentals of Fixed Prosthodontics</i> **Terry E. Donovan (2006) Longevity of the Tooth/Restoration Complex: A Review** <sub>Lecture 1!</sub>  #### Rationale for Crown Placement When determining if a tooth requires a crown, the following factors must be considered: - **Destruction of tooth structure**: Extent of existing damage or decay. - **Aesthetics**: Visual requirements of the restoration. - **Plaque Control / Moisture Control**: Ability to maintain hygiene and isolation. - **Retention**: Necessity for long-term stability of the restoration. #### Clinical Evidence and Longevity - **Resistance to Removal**: Comparison of resistance to removal forces for various crown types (e.g., MOD, mesio-occlusodistal). - **Reference**: Terry E. Donovan (2006) *Longevity of the Tooth/Restoration Complex: A Review*. Clinical photo (Figure 3a) showing a patient's mouth with severe dental decay and multiple gold crowns. The caption notes that patients abusing methamphetamine often present with rampant caries. **Treatment planning** • Assessing the tooth (+assessing all the dentition and the patient) **Principles of Tooth Preparations** **ABUTMENT TOOTH** • Principles of tooth preparation • Partial or complete preparation **BIOLOGICAL** • Conservation of tooth structure • **Avoidance of overcontouring** • Supragingival margins • Harmonious occlusion • Protection against tooth fracture **MECHANICAL** • Retention form • Resistance form • Deformation **AESTHETIC** • Minimum display of metal • Maximum thickness of porcelain • Porcelain occlusal surfaces • Subgingival margins ****   #### Abutment Tooth Considerations - Principles of tooth preparation - Selection between partial or complete preparation #### Biological Principles - **Conservation of tooth structure**: Minimizing unnecessary reduction. - **Avoidance of overcontouring**: Maintaining natural tooth profiles. - **Supragingival margins**: Preferring margins above the gumline when possible. - **Harmonious occlusion**: Ensuring proper bite alignment. - **Protection against tooth fracture**: Strengthening the remaining structure. #### Mechanical Principles - **Retention form**: Preventing removal of the restoration along the path of insertion. - **Resistance form**: Preventing dislodgement by forces directed apically or obliquely. - **Deformation**: Ensuring the restoration maintains its shape under functional loads. #### Aesthetic Principles - Minimum display of metal - Maximum thickness of porcelain for depth of color - Porcelain occlusal surfaces - Subgingival margins (where aesthetically necessary) Illustration of tooth preparation principles under 'ABUTMENT TOOTH'. Top panel shows a cross-section of a tooth with an arrow indicating partial or complete preparation. Bottom panels show two views of teeth with different margin placements (supragingival and subgingival). Three-panel diagram illustrating consequences of overcontouring on tooth preparations. Panel A: Cross-section showing normal gingiva and flow of food. Panel B: Shows injury to gingiva due to undercontoured crown. Panel C: Shows plaque retention due to overcontoured crown, with red arrow labeled 'Patient can't clean this!' pointing to the problematic area. **Treatment planning** * Assessing the tooth (+assessing all the dentition and the patient) “3 and 25% of teeth prepared for full coverage crowns will lose vital pulp functions within 15–20 years, with previously compromised teeth failing worse than those that are more intact” **Home > Extra-Coronal Restorations > Chapter** **Preserving Pulp Vitality** Chapter | First Online: 01 August 2018 THE UNIVERSITY OF WESTERN AUSTRALIA Many teeth prepared for extra-coronal restoration s have already endured cycles of disease and direct restoration. They should be evaluated carefully before preparation to minimise the risks of unexpected pulp breakdown. In this case we see a prepared lower premolar with multiple amalgam restorations and a buccal composite repair that make up the core  #### Preserving Pulp Vitality Research indicates that between 3% and 25% of teeth prepared for full coverage crowns will lose vital pulp functions within 15–20 years. Teeth that are previously compromised exhibit higher failure rates than those that are more intact. #### Pre-operative Evaluation Many teeth requiring extra-coronal restorations have already undergone multiple cycles of disease and direct restoration. Careful evaluation is required before preparation to minimize the risks of unexpected pulp breakdown. **Clinical Example:** - A prepared lower premolar featuring multiple amalgam restorations and a buccal composite repair acting as the core. Clinical photo of a prepared lower premolar showing multiple amalgam restorations and a buccal composite repair making up the core. The tooth is surrounded by gingival tissue. # Preparation stage ## Before patient arrives: - Decide on material of choice. Why is that material the best? - Approval of treatment plan (more on this later) - Wax up of tooth if any modifications require for existing tooth + putty key ## Day of preparation - Bring patient in, confirm treatment with them quickly, make sure they know what’s happening - Administer LA. (If you don’t have up to date opposing model because you did other restorative work since the diagnostic model, then take new impression. If you don’t have putty key, do it now) - Prep tooth according to guidelines for the correct materials. Check for undercuts and sufficient occlusal clearance - Make provisional restoration - Retraction cord + expasyl - Impressions, remove retraction cord! - Temporise   #### Pre-Appointment Planning - **Material Selection**: Decide on the material of choice and justify why that specific material is the best option for the case. - **Treatment Plan**: Ensure the treatment plan has been approved. - **Diagnostic Aids**: Complete a wax-up of the tooth if any modifications to the existing tooth are required, and prepare a putty key. #### Clinical Procedure Workflow - **Patient Reception**: Confirm the treatment plan with the patient and ensure they are fully informed of the procedure. - **Anesthesia and Preliminary Steps**: - Administer local anesthetic (LA). - Update records: If restorative work has been performed since the diagnostic model was made, take a new impression for an up-to-date opposing model. - If a putty key has not been made previously, create one at this stage. - **Tooth Preparation**: Prepare the tooth according to the specific guidelines for the chosen material. Verify the absence of undercuts and ensure there is sufficient occlusal clearance. - **Provisionalization and Impressions**: - Fabricate the provisional restoration. - Apply retraction cord and Expasyl. - Take final impressions. - **Crucial**: Remove the retraction cord. - Place the temporary restoration. Labelled diagram showing recommended reduction for all-ceramic crowns. The figure displays a tooth preparation outline with specific measurements: 1 mm reduction at the buccal and lingual margins, and 1.5 mm reduction on the occlusal surface. Diagram illustrating margin design considerations for all-ceramic crowns. It shows a sloping shoulder margin with arrows indicating force distribution (F). A callout box states 'Margin design should result in favorable stress distribution.' The caption explains that incisal loading leads to tensile stresses near the margin if forces are not reciprocated, which may cause brittle failure. **TRY-IN PROCEDURE** **Evaluation:** Seating, fitting, contact points Systematic approach 1. Evaluation of the crown on the die 2. Seating the crown on the prepared tooth 3. Assessment of the seated crown The image includes a logo for **The University of Western Australia** and the **Oral Health Centre of Western Australia**. There is also a speaker icon in the bottom right corner. #### Systematic Evaluation Approach The evaluation of indirect restorations involves a systematic approach to seating, fitting, and contact points, following these steps: 1. Evaluation of the crown on the die 2. Seating the crown on the prepared tooth 3. Assessment of the seated crown # Lab steps After the crown is returned from the lab we must check the **crown**. Upon receiving the crown from the dental laboratory, a thorough inspection of the restoration must be performed. # TRY-IN PROCEDURE ### THE UNIVERSITY OF WESTERN AUSTRALIA | Oral Health Centre of Western Australia ## EVALUATION OF CROWN ON THE DIE ### **Aims:** * Detection of fabrication errors (laboratory related) prior to the clinical appointment * Save critical chair time * Anticipation of problems before clinical appointment * Consider good lighting and magnification * In case of problem, consult with the dental laboratory   #### Objectives of Pre-Clinical Evaluation - **Detection of fabrication errors:** Identify laboratory-related issues prior to the clinical appointment. - **Efficiency:** Save critical chair time by anticipating problems before the patient arrives. - **Quality Assurance:** Utilize good lighting and magnification during inspection. - **Communication:** Consult with the dental laboratory immediately if problems are identified. Clinical photo showing a dental die (model) with a green impression material and pink gingival tissue. A set of fabricated teeth (crown/bridge) is seated on the die to demonstrate the try-in procedure for evaluating fit. Clinical photo showing a close-up view of the same dental die setup as above, highlighting the occlusal surface of the teeth during evaluation. **TRY-IN PROCEDURE** EVALUATION OF CROWN ON THE DIE Assess the die and opposing model • Poor pouring • Overtrimming • Fracture • Scratches • Wear  #### Assessment of Die and Opposing Model Inspect the models for the following defects: - Poor pouring - Overtrimming - Fractures - Scratches - Wear Clinical photo showing a close-up of a yellow dental die (model) held between fingers. A red rectangle highlights the crown area on the die, and a pencil tip is used to point at or inspect the margin of the crown. This visual demonstrates the 'Evaluation of Crown on the Die' step in the try-in procedure. **TRY-IN PROCEDURE** EVALUATION OF CROWN ON THE DIE **Internal surface:** * **Casting problems:** air bubbles * **Casting nodules or blebs** * Ideally, the **casting** should touch the die at the margins only <strong>Die spacer</strong>  #### Internal Surface Inspection - **Casting Problems:** Check for air bubbles, casting nodules, or blebs. - **Seating Principles:** Ideally, the casting should touch the die at the margins only. - **Die Spacer:** Verify the appropriate application and space for luting agents. Clinical photo of a dental crown being evaluated on a die. A gold-colored dental bur is shown inspecting the internal surface of the crown, which is seated against a pink die spacer. The image demonstrates the 'Internal surface' evaluation step mentioned in the text. **TRY-IN PROCEDURE** The University of Western Australia | Oral Health Centre of Western Australia **EVALUATION OF CROWN ON THE DIE** **Overall fit and resistance:** - Looseness - Excessive gap - Proximal contact areas **Marginal fit:** - Open margins - Overhangs or underextensions #### Overall Fit and Resistance - **Stability:** Check for looseness or excessive gaps. - **Proximal Contacts:** Evaluate the accuracy of proximal contact areas. #### Marginal Integrity - **Marginal Fit:** Inspect for open margins. - **Contour Errors:** Identify any overhangs or underextensions. Slide titled 'TRY-IN PROCEDURE' from The University of Western Australia / Oral Health Centre. It outlines the 'EVALUATION OF CROWN ON THE DIE'. The slide is split into two columns: 'Overall fit and resistance:' listing Looseness, Excessive gap, Proximal contact areas (with red arrows pointing to these items); and 'Marginal fit:' listing Open margins, Overhangs or underextensions. **TRY-IN PROCEDURE** THE UNIVERSITY OF WESTERN AUSTRALIA | Oral Health Centre of Western Australia **EXTERNAL SURFACE** * Appearance (restoration design) * Contour * Shade * Rough or smooth (polished) **OCCLUSION (ARTICULATOR)** * Centric contacts * Eccentric contacts * Interferences **EVALUATION OF CROWN ON THE DIE**  #### External Surface Characteristics - **Restoration Design:** General appearance and anatomical form. - **Contour:** Proper emergence profile and axial contours. - **Esthetics:** Shade matching. - **Finish:** Surface texture (rough vs. smooth/polished). #### Articulator Occlusion Assessment - **Centric Contacts:** Verification of static occlusion. - **Eccentric Contacts:** Evaluation of lateral and protrusive movements. - **Interferences:** Identification of any occlusal discrepancies. Clinical photo of anterior teeth showing the external surface evaluation context. The image displays a close-up view of upper front teeth (incisors) with visible restorations or crowns on the central incisors and lateral incisors. The teeth exhibit natural translucency and color variation, with smooth surfaces consistent with polished ceramic or composite materials. This visual supports the 'External surface' section text regarding appearance, contour, shade, and polish. The University of WA Insert Appointment: * Bring patient in, administer LA if required * Remove temporary crown. Can sometimes wiggle it off. If not possible, carefully section temp crown and break the temporary. * Clean off temporary cement with ultrasonic scaler * Try-In #### Appointment Preparation and Initial Steps - Bring patient in, administer local anesthetic if required - Remove temporary crown - Attempt to wiggle it off first - If not possible, carefully section the temporary crown and break it - Clean off temporary cement with an ultrasonic scaler - Proceed to Try-In # TRY-IN PROCEDURE ## SEATING THE CROWN **Remove the provisional restoration** * Excavator, sickle probe * Hemostat, Backhaus forceps, pliers * Crown remover: * Back-action crown remover * Automatic crown remover * Richwill crown remover HOW TO REMOVE A PFM CROWN #### Methods and Tools for Removal - **Hand Instruments:** Excavator, sickle probe - **Grasping Instruments:** Hemostat, Backhaus forceps, pliers - **Crown Removers:** - Back-action crown remover - Automatic crown remover - Richwill crown remover #### Procedure Note - How to remove a PFM crown A multi-panel clinical procedure image titled 'HOW TO REMOVE A PFM CROWN'. The visual sequence demonstrates the removal of a provisional crown using specific instruments (indicated by text on the left). It shows: 1) An intact tooth with red markings indicating the fracture line; 2) A close-up of the tooth split vertically down the middle; 3) A dental bur tool used for cutting; 4) The tooth with the crown sectioned off; 5) The final result showing the prepared tooth and removed restoration. This figure visually corresponds to the textual instructions for removing the provisional restoration. **TRY-IN PROCEDURE** ORAL HEALTH CENTRE OF WESTERN AUSTRALIA **IDEAL CROWN** * Easily seated * Stable * Accurate occlusal contact * Adequate proximal contacts * Accurate marginal fit * Aesthetic #### Characteristics of an Ideal Crown - Easily seated - Stable - Accurate occlusal contact - Adequate proximal contacts - Accurate marginal fit - Aesthetic **The University of Western Australia** **Oral Health Centre of Western Australia** **TRY-IN PROCEDURE** # SEATING THE CROWN * The crown should seat on the prepared tooth without forcing * If it is not seating, possible **causes** may involve: **Single crown** * Proximal contacts * Internal fit * Inaccurate margins/ over extensions * Retained temporary cements * Trapped gingival tissue  #### Seating Requirements and Troubleshooting - The crown should seat on the prepared tooth without forcing - If a single crown is not seating, possible causes include: - Proximal contacts - Internal fit - Inaccurate margins or over-extensions - Retained temporary cements - Trapped gingival tissue Clinical diagram illustrating the seating of a crown. The image features a cross-sectional view of a tooth and a crown (highlighted in yellow). A magnified circular inset provides a detailed view of the crown's interface with the prepared tooth structure, demonstrating the fit. **Try-In** Order to check: a) Proximal contact b) Internal fit c) Marginal fit #### Sequence of Evaluation 1. Proximal contact 2. Internal fit 3. Marginal fit # TRY-IN PROCEDURE ## SEATING THE CROWN ### Proximal contacts * Assess tightness with dental floss * There should be some tightness but not too difficult * Articulating paper (20 μm), marking liquid (Accufilm), sprays (occlude) * The shim stock (8 μm) should just pass through the contact * Minor adjustment at a time * If the contacts are open, return to the laboratory for material addition   #### Assessment and Adjustment of Proximal Contacts - Assess tightness with dental floss; there should be some tightness but it should not be too difficult to pass - Use articulating paper (20 μm), marking liquid (Accufilm), or sprays (Occlude) to identify contact points - Shim stock (8 μm) should just pass through the contact - Perform minor adjustments one at a time - If contacts are open, return the restoration to the laboratory for material addition Photo of dental materials: two small bottles labeled 'AccuFilm' (one with a white cap and one with a blue cap) and a blue applicator tip. These correspond to the 'marking liquid (Accufilm)' mentioned in the text for assessing proximal contacts. Photo of dental products: three spray cans labeled 'OCCLUDE' (occlusion marking spray) and a tube of paste. These items correspond to the 'sprays (occlude)' listed in the bullet points for seating the crown. # TRY-IN PROCEDURE ## SEATING THE CROWN ### Proximal contacts    #### Proximal contacts Clinical photo showing a dental crown try-in with blue articulating paper placed on the occlusal surface. Gloved fingers hold the tooth model to demonstrate seating and proximal contact verification. Clinical photo of a second angle or different crown during try-in, also using blue articulating paper. A black arrow points to a specific area on the occlusal surface, likely indicating wear pattern or contact point for evaluation. Diagrammatic illustration of a dental setup with metal clamps holding a red band around teeth models. A gold-colored crown is shown with a speaker icon and sound waves, possibly indicating acoustic feedback or communication during the procedure.   Clinical photo showing a dental crown with proximal contacts marked by red material (likely articulating paper or wax) to demonstrate seating and contact points against adjacent teeth. Clinical photo of a tooth model with a crown being seated, showing red markings indicating the location of proximal contacts for verification during the try-in procedure. # TRY-IN PROCEDURE The University of Western Australia | Oral Health Centre of Western Australia <h1>SEATING THE CROWN</h1> **Internal fit** ► The restoration should seat completely without interference of the occlusal or axial surfaces ► The fitting surface should be checked and adjusted accordingly - Disclosing medium (Fit Checker, LB impression material) - Spraying thin layer of aerosol indicator (Occlude) ► The relief can be achieved with a diamond bur   #### Evaluation and Adjustment of Internal Fit - The restoration should seat completely without interference from the occlusal or axial surfaces - Check the fitting surface and adjust accordingly using: - Disclosing medium (Fit Checker, light body impression material) - Aerosol indicator spray (Occlude) - Relief can be achieved using a diamond bur Photo of a green box labeled 'FIT CHECKER' and a tube of disclosing medium next to it. Photo of a white jar labeled 'Kerr Disclosing Wax' with a blue label. TRY-IN PROCEDURE **SEATING THE CROWN** Internal fit Fit Checker application - Penetrated areas of the medium indicate high spots - Can be adjusted accordingly #### Fit Checker Application - Penetrated areas of the medium indicate high spots - Adjust high spots accordingly # TRY-IN PROCEDURE **THE UNIVERSITY OF WESTERN AUSTRALIA** Oral Health Centre of Western Australia ## SEATING THE CROWN ### Internal fit If crown fits the model well but does not seat in the mouth, consider problems with impression **Caused by:** * Early impression removal * Distortion of impression * Latex contamination Take a new impression #### Troubleshooting Discrepancies If the crown fits the model well but does not seat in the mouth, consider problems with the impression. **Causes:** - Early impression removal - Distortion of impression - Latex contamination **Action:** Take a new impression Black downward-pointing arrow indicating a procedural step in the 'TRY-IN PROCEDURE' flowchart, specifically leading from impression problems to the instruction 'Take a new impression'. **TRY-IN PROCEDURE** [The University of Western Australia logo] [Oral Health Centre of Western Australia logo] SEATING THE CROWN **Marginal fit** • Should be as accurate as possible • Poor marginal adaptation: - Gap (100 micron is the borderline for acceptability) - Overhang - Under extension - Ledge #### Marginal Adaptation Standards - Fit should be as accurate as possible - Poor marginal adaptation includes: - Gap (100 microns is the borderline for acceptability) - Overhang - Under-extension - Ledge Procedural icon representing the 'TRY-IN PROCEDURE' section. The visual shows a speaker symbol with radiating lines, indicating audio content or a step in a process related to seating a crown and checking marginal fit. **TRY-IN PROCEDURE** [Logo: University of Western Australia, Oral Health Centre of Western Australia] **SEATING THE CROWN** **Marginal fit** **Ideal** **Overextended** **Underextended** **Overhang** **Open margin**  #### Marginal Fit Classifications - Ideal - Overextended - Underextended - Overhang - Open margin A labeled diagram illustrating the 'SEATING THE CROWN' procedure, specifically focusing on 'Marginal fit'. The image displays five side-profile views of a dental crown (yellow) over a tooth preparation (grey). From left to right, the diagrams are labeled: 'Ideal', showing perfect alignment; 'Overextended', where the crown extends beyond the margin; 'Underextended', where the crown falls short of the margin; 'Overhang', where excess material overlaps the margin; and 'Open margin', showing a gap between the crown and the tooth structure. Red circles highlight the specific marginal areas for each condition. **TRY-IN PROCEDURE** **SEATING THE CROWN** **Marginal fit** **Effects of open margins:** * Sensitivity * Dissolution of cement * Plaque retention * Caries * Gingival inflammation #### Clinical Effects of Open Margins - Sensitivity - Dissolution of cement - Plaque retention - Caries - Gingival inflammation **-Iane**-THE UNIVERSITY OF <font color="#0000a1"></font>WESTERN AUSTRALIA>- ### **TRY-IN PROCEDURE** **SEATING THE CROWN** **Marginal fit** * Poor marginal fit can be due to inability to read the finish line by the technician Overhangs/overextension: can be adjusted Underextention: may require remake Gap: require remake #### Causes and Corrective Actions - Poor marginal fit may be due to the technician's inability to read the finish line - **Overhangs/Overextension:** Can be adjusted - **Under-extension:** May require a remake - **Gap:** Requires a remake Visual icon representing the 'TRY-IN PROCEDURE' step. The image displays a grey speaker symbol with sound waves emanating from it, indicating audio playback or a narration component associated with this procedural slide. # **TRY-IN PROCEDURE** | **THE UNIVERSITY OF WESTERN AUSTRALIA** | **Oral Health Centre of Western Australia** ## SEATING THE CROWN ### Marginal fit ### Gingivo-occlusal direction ### Occluso-gingival direction ### Both    #### Directions of Evaluation - Gingivo-occlusal direction - Occluso-gingival direction - Both Labelled diagram illustrating the 'Gingivo-occlusal direction' of seating a crown. It shows a cross-section of a tooth preparation (yellow) with a crown margin (blue). A red arrow points up along the gingival wall and another points down into the occlusal seat to demonstrate checking the marginal fit. Labelled diagram illustrating the 'Occluso-gingival direction' of seating a crown. It shows a similar cross-section where a red arrow points down from the occlusal surface and another points up along the gingival wall, demonstrating the path of insertion. Labelled diagram illustrating the 'Both' directions for seating a crown. It depicts arrows moving both up and down within the crown preparation, indicating a check in all directions. Below this panel is the text 'New impression', suggesting that if the fit is not verified correctly, a new impression must be taken. The University of Western Australia | Oral Health Centre TRY-IN PROCEDURE SEATING THE CROWN Marginal fit Adjust overextended margins or overhangs from the external surface, not the fitting surface  #### Adjustment Technique - Adjust overextended margins or overhangs from the external surface, not the fitting surface Labelled diagram illustrating the 'Marginal fit' step of seating a crown. It demonstrates two outcomes: the top path shows a correct fit with a green checkmark and arrow indicating proper adjustment from the external surface; the bottom path shows an incorrect overhang with a red 'X' and callout highlighting the fitting surface that should not be adjusted. **TRY-IN PROCEDURE** logo image of The University of Western Australia | Oral Health Centre of Western Australia **ASSESSMENT OF THE SEATED CROWN** Aims * Check * Stability * Contour * Occlusion * Aesthetics * Confirm the suitability for cementation #### Aims of Assessment Check the following to confirm suitability for cementation: - Stability - Contour - Occlusion - Aesthetics Logo image of The University of Western Australia and Oral Health Centre of Western Australia. This visual element serves as an institutional identifier for the slide. # TRY-IN PROCEDURE  ### ASSESSMENT OF THE SEATED CROWN #### Stability - Restoration should not rotate when the force is applied - Instability causes failure in function (mainly in cementation) internal surface misfit ↓ caused by distortion in impression or fabrication process  #### Stability Requirements - The restoration should not rotate when force is applied. - Instability causes failure in function, primarily during cementation. #### Internal Surface Misfit - Instability is often caused by internal surface misfit resulting from distortion in the impression or the fabrication process. 3D rendered diagram of a seated dental crown on a tooth model. A green arrow points to the crown margin, indicating the seating or fit assessment area. White lines are shown tracing from the inner surface of the crown down into the prepared tooth structure, illustrating the path for checking internal surface misfit. <fileестерни> - **HEADER**: [University of Western Australia logo], Oral Health Centre of Western Australia - **TITLE**: TRY-IN PROCEDURE - **SUB-HEADERS**: ASSESSMENT OF THE SEATED CROWN, Contour - **ID_TEXT**: Adequate crown contour, Flow of food, Flow of food, Gingiva, Gingiva, (Cross section), Injury, Injury, Undercontoured crown, Overcontoured crown, Plaque retention, Plaque retention. </file> **TRY-IN PROCEDURE** **ASSESSMENT OF THE SEATED CROWN** **Contour** ► Improper contour may impair gingival health and affects the natural appearance ► They must be adjusted before cementation    #### Gingival Health and Appearance - Improper contour may impair gingival health and affects the natural appearance. - Contours must be adjusted before cementation. #### Effects of Improper Contouring - **Undercontoured crown:** May lead to food impaction and potential injury to the gingiva. - **Overcontoured crown:** Often results in plaque retention and gingival inflammation. Labelled cross-section diagram illustrating 'Adequate crown contour'. Shows a tooth with proper contours allowing normal 'Flow of food' between the tooth and gingiva. The diagram is annotated with labels for 'Gingiva', 'Flow of food', and '(Cross section)'. Arrows indicate the direction of food flow. Labelled cross-section diagram illustrating an 'Undercontoured crown'. Shows a tooth that is too narrow or under-contoured, causing food to impinge directly on the gingiva, resulting in 'Injury'. Annotates the condition as 'Undercontoured crown'. Labelled cross-section diagram illustrating an 'Overcontoured crown'. Shows a tooth that is too bulky, trapping food and leading to 'Plaque retention'. Includes a speaker icon indicating noise or discomfort. Annotates the condition as 'Overcontoured crown'. **TRY-IN PROCEDURE** The University of Western Australia Oral Health Centre of Western Australia **ASSESSMENT OF THE SEATED CROWN** **Occlusion** * The crown should be fully seated * Major adjustments should be done prior to cementation * Minor adjustments can be completed after cementation * Inadequate occlusal contacts can be caused by * Poor occlusal recording * Poor articulation #### General Principles - The crown should be fully seated. - Major adjustments should be done prior to cementation. - Minor adjustments can be completed after cementation. #### Causes of Inadequate Occlusal Contacts - Poor occlusal recording - Poor articulation # TRY-IN PROCEDURE **THE UNIVERSITY OF WESTERN AUSTRALIA** | **Oral Health Centre of Western Australia** ## ASSESSMENT OF THE SEATED CROWN ### Occlusion #### Shim stock assessment * **The shim stock will determine if an occlusal contact is present** * **Assess the occlusion on all teeth with and without the prosthesis** * **Assess the occlusion on the crown** 8 µm thick  #### Shim Stock Assessment - Use shim stock (8 µm thick) to determine if an occlusal contact is present. - Assess the occlusion on all teeth with and without the prosthesis. - Assess the occlusion specifically on the crown. Clinical photo demonstrating the 'Shim stock assessment' procedure for a seated crown. It shows a dental instrument placing a thin strip of material (identified by OCR as '8 µm thick') between the occlusal surfaces of adjacent teeth to check for contact. <strong>Try-in Procedure</strong> <img>Dental procedure showing insertion of 8 μm carbon sheet between premolars<img> **Analysis of Active Oral Tactile Sensitivity in Individuals with Complete Natural Dentition** Tiago HS Anastacio, Nathalia B de Moraes, Eduardo J de Moraes, Valquiria Quinelato, Jose A Calasans-Maia, Cintia CP Martins, Telma Aguiar, Aldir N Machado, Priscila L Casado **Abstract** **Aim:** To evaluate the active tactile sensitivity in individuals with complete natural dentition, determining the smallest thickness detected by the participants, and clarifying if there is a difference between the thicknesses analyzed. **Materials and methods:** Active tactile sensitivity was evaluated in 40 research participants. Inclusion criteria included participants with complete natural dentition, without active or history of periodontal disease, absence of temporomandibular disorders, bruxism, and restorations in the evaluated area. Exclusion criteria included age below 18 years. The active tactile perception threshold was evaluated by using carbon sheets of different thicknesses (0, 12, 24, 40, 80, 100, and 200 μm), which were inserted in the participants’ premolars, bilaterally. The carbon sheet was inserted so as not to come into contact with the oral soft tissues. Subsequently, the participant occluded and was asked about the perception of the intraocclusal object 20 times in each occlusal contact. The collected data were tabulated considering the amount of positive and negative responses for each carbon thickness. Values of p < 0.05 were considered significant. **Results:** The results showed that there was linearity in perception, on both sides, besides, the natural dentition was able to perceive difference in thickness from 12 μm. **Conclusion:** We conclude that the 12 μm thickness is noticeable in occlusion and can be differentiated from other thicknesses in natural dentition and that there is no difference between the tactile sensitivity of the right and left sides. **Clinical significance:** A better understanding of active oral tactile sensitivity will contribute to numerous clinical applications in dentistry, including occlusal adjustment in dental rehabilitation, dental implants prosthesis design, and survival of prosthetic rehabilitation. **Keywords:** Active tactile sensitivity, Dental occlusion, Mechanoreceptors, Oral proprioception, Periodontal ligaments, Permanent dentition. The Journal of Contemporary Dental Practice (2021): 10.5005/jp-journals-10024-3069 **8 μm thick** #### Active Oral Tactile Sensitivity Research indicates that individuals with complete natural dentition can perceive differences in thickness from 12 μm. This sensitivity is critical for: - Occlusal adjustment in dental rehabilitation. - Dental implant prosthesis design. - Survival of prosthetic rehabilitation. Note: 8 μm thick shim stock is used for clinical assessment. Clinical photo showing a dental try-in procedure. A thin carbon sheet (labeled in text as '8 μm thick') is being inserted between the premolars of a patient's upper and lower teeth using a dental instrument. The image demonstrates the method for evaluating active oral tactile sensitivity described in the abstract. **TRY-IN PROCEDURE** <TOP RIGHT LOGOS: THE UNIVERSITY OF WESTERN AUSTRALIA AND ORAL HEALTH CENTRE OF WESTERN AUSTRALIA> **ASSESSMENT OF THE SEATED CROWN** **Occlusion** **Articulating paper assessment** * Mark heavy contacts or interferences in centric and eccentric * Articulating paper will locate the contact area * Use different colors for different movements    #### Articulating Paper Assessment - Mark heavy contacts or interferences in centric and eccentric movements. - Articulating paper is used to locate the specific contact area. - Use different colors to distinguish between different movements. Clinical photo showing a dental model with multiple teeth. Two posterior teeth are prepared crowns with heavy blue markings indicating occlusal contacts, while adjacent natural teeth have light blue dots marking contact points. Product photograph of articulating paper holders (red and blue) used to apply articulating paper to teeth during the try-in procedure. Photograph of an 'ARTICULATING PAPER' box packaging alongside strips of red and black paper, illustrating different colors used for different movements as mentioned in the text. TY-RIN PROCEDURE THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia ASSI SSMENT OF THE SEATED CROWN Occlusion Protision Lateroprotsusion MIC Dark articulating paper (blues) for CR or maximal intercuspation position Lighter articulating paper (red) for eccentric position  #### Movement Marking Protocols - **Centric Relation (CR) or Maximal Intercuspation (MIC):** Use dark articulating paper (e.g., blue). - **Eccentric Positions (Protrusion/Lateroprotrusion):** Use lighter articulating paper (e.g., red). Clinical photo of the upper dental arch showing a seated crown with occlusal contacts marked by articulating paper. Red marks indicate eccentric position contacts (lateroprotrusion), blue marks indicate centric relation or maximal intercuspation position contacts (MIC). Labels point to specific regions: 'Protrusion', 'Lateroprotrusion', and 'MIC'. The slide presents the "TRY-IN PROCEDURE" from The University of Western Australia Oral Health Centre. **ASSESSMENT OF THE SEATED CROWN** **Occlusion** * **Premature contact (centric)** * Adjust grooves or cusp inclines * Never the tip of cusp * **Interferences (eccentric)** * Adjust cusp inclines * Tip of cusps if necessary  #### Adjustment Guidelines - **Premature contact (centric):** - Adjust grooves or cusp inclines. - Never adjust the tip of the cusp. - **Interferences (eccentric):** - Adjust cusp inclines. - Adjust the tip of cusps only if necessary. Clinical photo demonstrating the 'TRY-IN PROCEDURE' for a seated crown. The image shows a close-up of an intraoral view where a dental technician is using a dental handpiece to adjust the occlusion of a newly placed crown on the patient's upper right posterior teeth. A gloved finger is retracting the cheek to provide access and visibility. **TRY-IN PROCEDURE** **ASSESSMENT OF THE SEATED CROWN** **Occlusion** The prosthesis thickness should be measured Thickness Gauge (Svensen Gauge) In some cases the opposing tooth can be adjusted   #### Measurement and Opposing Teeth - The prosthesis thickness should be measured using a Thickness Gauge (Svensen Gauge). - In some cases, the opposing tooth can be adjusted to achieve proper occlusion. Clinical photo showing a dental instrument holding a tooth-like prosthesis against a blue background, demonstrating the assessment of the seated crown. Close-up clinical photo of a metal Thickness Gauge (Svensen Gauge) being used to measure the thickness of a dental structure. The gauge has visible numerical markings including '0', '1', and '2'. **TRY-IN PROCEDURE** THE UNIVERSITY OF **WESTERN AUSTRALIA** Oral Health Centre of Western Australia Clinical photo showing a dental try-in procedure. The image displays two posterior teeth with black dots (likely diagnostic markers or staining) and a large silver amalgam restoration on the right tooth. A dental instrument with a textured head is visible in the upper left corner. Clinical photo showing a similar dental view to the first panel, likely demonstrating the same procedure from a slightly different angle or at a different stage. It features the same two posterior teeth with an amalgam filling and black spots, with a dental tool visible near the gum line of the left tooth. # TRY-IN PROCEDURE Diagram illustrating a dental try-in procedure. The image is divided into four panels showing the preparation and placement of a crown or bridge. Top-left: A cross-section of a tooth with a yellow outer layer and pink inner core, showing the initial shape. Bottom-left: A similar cross-section but with an added red margin at the top edge, indicating adjustment or fit. Top-right: An occlusal view of a prepared tooth structure with pink internal anatomy visible through translucent enamel-like layers. Bottom-right: A fully assembled crown or bridge in place, with pink anatomical features visible within the structure, demonstrating final fit. # TRY-IN PROCEDURE    Left panel of a diagram illustrating the occlusal relationship between two opposing posterior teeth during a try-in procedure. The teeth are depicted in cross-section with enamel (yellow), dentin (orange), and pulp chamber (pink) visible. A thin red line indicates the contact point or marginal gap at the interface. Top-right panel showing an occlusal view of a single tooth model, likely representing the preparation for a crown or bridge. The surface is segmented into anatomical areas (pink regions) outlined by green lines, with an orange gingival margin at the top. Bottom-right panel showing another occlusal view of a tooth model, similar to the one above but with different segmentation patterns on the pink surface area. This appears to be part of the same set demonstrating different configurations or stages of the try-in procedure. **TRY-IN PROCEDURE** The University of Western Australia Oral Health Centre of Western Australia  Educational diagram illustrating a dental 'TRY-IN PROCEDURE'. The visual is split into two columns showing the progression of a tooth preparation. The left column displays cross-sectional views of a yellow tooth structure with a pink internal core (pulp). The top-left image shows an initial preparation shape, while the bottom-left shows a modified shape with a distinct M-shaped cavity floor. The right column depicts the corresponding 3D occlusal view of the prepared tooth surface in pink and orange tones, demonstrating how the preparation changes from a flatter surface to one with defined cusps and grooves matching the cross-sections on the left. **TRY-IN PROCEDURE** THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia Diagram illustrating the 'TRY-IN PROCEDURE' for a dental restoration. The image displays four panels: two showing cross-sections of tooth preparations with yellow and pink layers representing different material stages or anatomical structures, and two showing occlusal views of teeth being prepared or restored using a dental handpiece (drill). The visual demonstrates sequential steps in fitting a dental crown or filling. **TRY-IN PROCEDURE** Clinical procedure diagram illustrating the 'TRY-IN PROCEDURE' for dental crowns. The image displays four distinct visual elements: two on the left show a yellow crown model with a pink internal structure (likely representing a core or fit check), and two on the right depict a tooth model being adjusted by a metallic dental instrument (such as a bur or explorer). The right-side panels illustrate the physical adjustment of the crown to the prepared tooth, demonstrating the step-by-step process of fitting and modifying the restoration. **TRY-IN PROCEDURE** THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia Diagram illustrating the 'TRY-IN PROCEDURE' for a dental crown. The image displays four panels: two cross-sectional views (left) showing the fit of a crown over a tooth preparation with pink material inside, and two occlusal/axial views (right) demonstrating the internal anatomy and margins of the crown on the prepared tooth structure. **TRY-IN PROCEDURE**  Labelled diagram illustrating the 'TRY-IN PROCEDURE' for a dental prosthesis. The image displays two distinct views: on the left, a cross-sectional view showing yellow outer layers (representing denture base or tissue) and pink inner structures (representing teeth or underlying anatomy), with a red gap indicating the fit between components; on the right, an external perspective of the same object showing segmented anatomical details. **TRY-IN PROCEDURE** The University of **Western Australia** Oral Health Centre of Western Australia Medical illustration demonstrating the 'TRY-IN PROCEDURE' for dental prosthetics. The image displays two main views: on the left, a cross-sectional view of two yellow tooth-like structures with pink internal cores showing their fit; on the right, corresponding occlusal (top-down) views of the same structures in pink and beige tones, illustrating surface anatomy and alignment. **TRY-IN PROCEDURE**  Diagram illustrating a 'TRY-IN PROCEDURE' for dental restorations. The image displays four panels: the left side shows two yellow tooth models with pink internal structures and red margins indicating fit; the right side shows corresponding occlusal views of teeth with pink restoration segments marked by red lines, likely representing adjustment points or contact areas during the try-in phase. **TRY-IN PROCEDURE** The University of Western Australia Oral Health Centre of Western Australia  Labeled diagram illustrating the 'TRY-IN PROCEDURE' for a dental prosthesis. The visual is divided into two main sections: on the left, yellow and pink schematic blocks represent the fit of the denture base (yellow) against the tooth structure; on the right, realistic anatomical renderings show the gingival tissue and teeth with pink occlusal surfaces and red indicators highlighting specific contact points or adjustments. **TRY-IN PROCEDURE** The University of Western Australia | Oral Health Centre of Western Australia  Medical diagram illustrating the 'TRY-IN PROCEDURE' for a dental crown. The image displays four panels: two showing cross-sections of a tooth preparation (yellow structure with pink pulp) and two showing the corresponding crown fitment (pink/white porcelain structure). Annotations indicate the relationship between the prepared tooth and the restorative crown. TRY-IN PROCEDURE The University of Western Australia Oral Health Centre of Western Australia Diagram illustrating the 'TRY-IN PROCEDURE' for dental restorations. The image displays four panels: two on the left show cross-sectional views of teeth with yellow and purple layers representing different material stages or components; two on the right depict clinical tooth models (pink enamel, orange gingiva) with a dental handpiece applying material to the occlusal surface. **TRY-IN PROCEDURE** THE UNIVERSITY OF WESTERN AUSTRALIA Oral Health Centre of Western Australia Medical diagram illustrating the 'TRY-IN PROCEDURE' for dental restorations. The image is split into two columns: left side shows occlusal views of teeth (yellow enamel, pink dentin/core) before and after preparation; right side shows buccal views with a dental handpiece performing grinding on the tooth structure. **TRY-IN PROCEDURE** The University of Western Australia | Oral Health Centre of Western Australia # ASSESSMENT OF THE SEATED CROWN ## Occlusion ► Completed adjustment - Well distributed occlusal contacts - Posterior teeth: the prosthesis and the remaining dentition should have the same occlusal contact and hold shim stock - Anterior teeth: the prosthesis should lightly hold shim stock if other anterior teeth do  #### Criteria for Completed Adjustment - Well distributed occlusal contacts. - **Posterior teeth:** The prosthesis and the remaining dentition should have the same occlusal contact and hold shim stock. - **Anterior teeth:** The prosthesis should lightly hold shim stock if other anterior teeth do. Clinical photo showing a dental cast with a seated crown (metal prosthesis) and adjacent teeth. Blue marks on the occlusal surfaces indicate shim stock placement to assess contact points. Red hand-drawn annotations highlight specific areas of occlusal contact on the posterior teeth, demonstrating the 'completed adjustment' and 'well distributed occlusal contacts' mentioned in the text. **# TRY-IN PROCEDURE** **# THE UNIVERSITY OF WESTERN AUSTRALIA** # Oral Health Centre of Western Australia ## ASSESSMENT OF THE SEATED CROWN **Aesthetics** * Patient approval should be obtained prior to cementation * Shade and morphology * Lighter shade: can be stained and glazed * Darker shade: should be cut back and followed by new ceramic application * Modify the morphology with diamond burs and soflec discs * Send back for glazing * Consider temporary cementation **Before** **After**   #### Patient Approval - Patient approval should be obtained prior to cementation. #### Shade and Morphology - **Shade Adjustments:** - Lighter shade: Can be stained and glazed. - Darker shade: Should be cut back followed by new ceramic application. - **Morphology Adjustments:** - Modify with diamond burs and Sof-Lex discs. - Send back to the laboratory for glazing after modification. #### Clinical Consideration - Consider temporary cementation to evaluate aesthetics in function. Clinical intraoral photograph labeled 'Before', showing a patient's upper and lower anterior teeth with existing dental restorations. The teeth appear yellowish in color. Clinical intraoral photograph labeled 'After', showing the same patient's mouth following the try-in procedure. The new crowns are visibly whiter and have improved morphology compared to the 'Before' image. A speaker icon is visible on this panel. # TRY-IN PROCEDURE **THE UNIVERSITY OF WESTERN AUSTRALIA** | **Oral Health Centre of Western Australia** ## ASSESSMENT OF THE SEATED CROWN ### Finishing and Polishing * **Metal:** rubber polishing wheels and points * **Ceramic:** Rough ceramic will wear the opposing teeth * Composite finishing rubber burs * Rubber cup and diamond polishing paste * Or send to laboratory for reglazing #### Material-Specific Protocols - **Metal:** Use rubber polishing wheels and points. - **Ceramic:** Rough ceramic will wear the opposing teeth. Options include: - Composite finishing rubber burs. - Rubber cup and diamond polishing paste. - Sending to the laboratory for reglazing. # TRY-IN PROCEDURE **THE UNIVERSITY OF WESTERN AUSTRALIA** Oral Health Centre of Western Australia ### ASSESSMENT OF THE SEATED CROWN **Finishing and Polishing** - Metal: **rubber** polishing wheels and points - **Ceramic**: Rough **ceramic** will wear the opposing teeth - Composite finishing **rubber** burs - **Rubber** cup and **diamond** polishing paste - Or send to laboratory for reglazing #### Polishing Procedures - **Metal:** Rubber polishing wheels and points. - **Ceramic:** It is essential to polish as rough ceramic wears opposing teeth. - Use composite finishing rubber burs. - Use rubber cup with diamond polishing paste. - Alternatively, return to the laboratory for professional reglazing. Procedure list detailing finishing and polishing steps for metal and ceramic crowns. Includes specific tools like rubber polishing wheels, composite finishing burs, and diamond polishing paste. # TRY-IN PROCEDURE ## Systematic approach ### 1. Evaluation of the restoration on the die a) Die and opposing model b) Internal surface of restoration c) Restoration on the model (die) ### 2. Seating the crown on the prepared tooth a) Proximal contact b) Internal fit c) Marginal fit ### 3. Assessment of the seated crown a) Stability b) Contour c) Occlusion d) Aesthetics # Questions? THE UNIVERSITY OF **WESTERN** **AUSTRALIA** [^1]: Original PDF page 1: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=1|DMD2 L2 Clinical Steps of Indirect Restoration, p.1]] [^2]: Original PDF page 2: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=2|DMD2 L2 Clinical Steps of Indirect Restoration, p.2]] [^3]: Original PDF page 3: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=3|DMD2 L2 Clinical Steps of Indirect Restoration, p.3]] [^4]: Original PDF page 4: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=4|DMD2 L2 Clinical Steps of Indirect Restoration, p.4]] [^5]: Original PDF page 5: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=5|DMD2 L2 Clinical Steps of Indirect Restoration, p.5]] [^6]: Original PDF page 6: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=6|DMD2 L2 Clinical Steps of Indirect Restoration, p.6]] [^7]: Original PDF page 7: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=7|DMD2 L2 Clinical Steps of Indirect Restoration, p.7]] [^8]: Original PDF page 8: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=8|DMD2 L2 Clinical Steps of Indirect Restoration, p.8]] [^9]: Original PDF page 9: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=9|DMD2 L2 Clinical Steps of Indirect Restoration, p.9]] [^10]: Original PDF page 10: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=10|DMD2 L2 Clinical Steps of Indirect Restoration, p.10]] [^11]: Original PDF page 11: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=11|DMD2 L2 Clinical Steps of Indirect Restoration, p.11]] [^12]: Original PDF page 12: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=12|DMD2 L2 Clinical Steps of Indirect Restoration, p.12]] [^13]: Original PDF page 13: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=13|DMD2 L2 Clinical Steps of Indirect Restoration, p.13]] [^14]: Original PDF page 14: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=14|DMD2 L2 Clinical Steps of Indirect Restoration, p.14]] [^15]: Original PDF page 15: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=15|DMD2 L2 Clinical Steps of Indirect Restoration, p.15]] [^16]: Original PDF page 16: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=16|DMD2 L2 Clinical Steps of Indirect Restoration, p.16]] [^17]: Original PDF page 17: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=17|DMD2 L2 Clinical Steps of Indirect Restoration, p.17]] [^18]: Original PDF page 18: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=18|DMD2 L2 Clinical Steps of Indirect Restoration, p.18]] [^19]: Original PDF page 19: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=19|DMD2 L2 Clinical Steps of Indirect Restoration, p.19]] [^20]: Original PDF page 20: [[DMD2 L2 Clinical Steps of Indirect Restoration.pdf#page=20|DMD2 L2 Clinical Steps of Indirect Restoration, p.20]] [^21]: Original PDF page 21: [[DMD2 L2 Clinical Steps of Indirect 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