Treatment Planning PDF

◾ I. Planning & Making Crowns II. Designing & Planning Bridges History & Examination Factors Affecting Selecting a Bridge Design (1) Considering the Whole Patient...

◾ I. Planning & Making Crowns II. Designing & Planning Bridges History & Examination Factors Affecting Selecting a Bridge Design (1) Considering the Whole Patient Support Patient attitude and informed consent Conservation of tooth structure Age Cleansability Sex Appearance Social history Cost Assessment of Abutment Teeth (2) Considering the Whole Mouth (1) General Procedure for Abutment Examination Oral hygiene Radiographic examination Condition of the remaining teeth Pulp assessment (3) Considering the Individual Tooth Removal of existing restoration, cavity liners, The value of the tooth and residual caries Appearance (2) Special Considerations for Abutment Teeth Condition of the crown of the tooth, the pulp, and periodontium Endodontically treated abutments Occlusion Unrestored abutments Root length Root surface area Root shape and angulation Detailed Planning of the Crown Periodontal disease Appearance Biomechanical consideration Shade Clinical modifications Assessing remaining tooth structure and its environment The need for a core III. Special Problems in Designing and Planning Fixed Partial Dentures (FPD) 1. Replacement of single missing tooth 2. Cantilever fixed partial dentures 3. Mesially tilted molar abutment 4. Pier abutments 5. Canine-replacement fixed partial dentures 6. Replacing multiple anterior teeth IV. Sequence of Treatment 1. Treatment of symptoms 2. Stabilization of deteriorating conditions 3. Definitive therapy  Planning & Making Crowns I  1. Assess patient cooperation. 2. Clearly explain: Treatment options Number of sessions Costs 3. Obtain written consent for the selected treatment plan to prevent future disputes. - Cooperative Patient: Allows for a complicated, time-consuming treatment plan with better outcomes. Non-Cooperative Patient: Requires a simpler, quicker treatment plan.  No upper age limit for crowns or bridges. Lower age limit differs: Crowns: No strict lower age limit. Ex SSC for paedo :. Bridges and Implants: Lower age limit is 18 years, due to bone and tissue growth. Bridges & Implants in Young Patients Minimum Age: 18 years. - Bridges: Pontics may restrict tissue growth beneath, affecting future development. - Implants: Bone growth may displace the implant, leading to ankylosis and malocclusion.  Historically · 1. 2 Teeth with early fractures and restorations develop secondary dentin, reducing pulp size earlier. Progressive growth may alter the gingival margin, making subgingival crown margins supragingival over time. J All-ceramic restorations solve esthetic concerns as they match tooth shade. GA/ Sedation - Improved behavior management techniques make dental treatment easier for children today.  This makes crown application easier at a younger age. Large pulp horns: Avoid crowns. Normal pulp size: Crown application is suitable. Avoid making assumptions based on gender. It is incorrect to assume that females are more concerned about esthetics than males. Focus on listening carefully to the patient’s concerns and desires regarding their esthetics.  The nature of the patient’s job may influence treatment choices. Occupation-Specific Needs (1) Wind Instrument Players: Retain incisor teeth to maintain their embouchure (lip contraction needed for playing). (2) Pipe Smokers: - Consider the impact of pipe stem clenching when designing or selecting crowns. Other examples: A singer, TV presenter, or public speaker requires excellent esthetic results and clear speech articulation. In some cases, temporary Consider the patient’s ability to attend solutions are necessary. multiple appointments or long ttt sessions. Cost vs. Care: ttt cost, careful in planning and execution. (1) Informed consent is (2) critical to avoid disputes or misunderstandings with the patient. long lifespan Always ensure For financially constrained patients: patients Present all possible treatment options. understand the Focus explanations on cost-effective treatments like dentures or basic restorations. cost implications Avoid spending time explaining high-cost options like implants or veneers unless of their treatment. the patient shows interest. Always examine the entire mouth, not just the area of the missing teeth, before starting prosthetic treatment.  Provide Oral Hygiene Instructions (OHI). Complex treatments like crowns or bridges Reevaluate in the next appointment. are not indicated until oral hygiene improves. - If improved: Proceed with treatment. Special Cases - If not improved: Treatment is contraindicated. Teenagers in Puberty: Hormonal changes can cause lapses in cleanliness and gingival inflammation. 16.1) E sig Example: A 13-year-old patient with poor hygiene after fixed ortho. ttt but requiring restorative care. Provide ttts that improve appearance to motivate better hygiene. Chep +j Contraindicated Treatments in Poor Oral Hygiene. B Avoid withholding Periodontal treatment must precede 1. Orthodontic Treatment (most affected). ttt to pressure pt’s 2. Laminated Veneers. prosthetic treatment, followed by into improving OH. surgery, conservative, and endodontic 3. Composite Veneers (Facing). treatments. Prosthetics come last.  If Insufficient posterior occlusion: Use metal-ceramic or strong ceramics for anterior crowns to endure mastication forces. Grade 1 Mobility: Teeth can serve as abutments after periodontal splinting (e.g., using a metal, ceramic, or fiber bar on the lingual Analyze the number of missing side to distribute forces). teeth and the complexity of the Example: A lower 4 is treatment plan. restored with a bridge If no extractions exist, make using lower 3 and 5 as maximum effort to save abutments. If both 3 and 5 remaining teeth (e.g., caries have Grade 1 mobility, removal, endodontic treatment, 1 splinting them allows their post and core). 7 use as abutments.  A tooth capable of acting as an abutment for restoring a missing tooth has high clinical value. The importance of a tooth varies based on: The canine is often the Location (e.g., canines vs. wisdom teeth). - last tooth considered for Function, occlusion, and esthetic impact. extraction The value of the tooth depends on the Example: Missing lower 7 with bone resorption. clinical scenario: Lower 6 & 8 are present, but the 8 is carious. Lower 8 is missing, upper 8 is present: Instead of extracting the 8, restore it (caries removal, RCT if needed) and use - The upper 8 can still serve as an it as a Strategic Abutment (the tooth most posterior to the edentulous space). abutment for a future bridge.  Unrealistic Expectations: Composite vs. Crown Patients with crowded teeth Modern composites (smile disharmony) and a have been developed to & gummy smile (high smile last 10-15 years, similar line) may opt for crowns to crowns. instead of orthodontics, Restoring teeth with leading to disappointment composite is more -1 when the gummy smile conservative, preserving becomes more noticeable. more tooth structure compared to crowns. Solution: Use mock-ups or digital simulations to show expected results before starting treatment.  Subgingival Caries/Fractures: Deep caries below the gingival margin Limited Tooth Structure: complicate crown preparation. Large composite fillings may leave minimal remaining tooth structure. Solution: During preparation, the remaining structure may be lost, and - If caries extend beyond the sulcus, composite fillings could dislodge during impression-taking. extraction is indicated. Solution: Refer the patient for post & core restoration to stabilize the - Periodontal surgery tooth before using it as an abutment. (e.g., gingivectomy or crown lengthening) may resolve the issue in less severe cases. Cas e s More than 2 years, minimal lesion: Proceed with the crown. Healing Period Consideration Newly treated teeth (~6 months), minimal lesion: Redo RCT and wait 6 months. D For small periapical lesions in Large lesion, any time: Redo RCT. symptomless teeth, the lesion Symptomatic tooth: Redo RCT. may be in the healing phase.  If there’s a risk of irreversible pulpitis, perform RCT before preparation. Avoid direct or indirect pulp capping for abutment teeth. Prolonged temporary restorations can compromise tooth structure. Orthograde Approach: Retreatment through the tooth crown. Remove old filling material, clean, reshape, and refill the canal from the coronal side to apex. Retrograde Approach: ↳ apexectomy Surgical access through the root apex. Clean the infected apex and place a filling directly at the root end. * Preferred Option: Ensures stability and avoids disturbing the apical seal.  Proper occlusion prevents excessive forces on restorations, which can lead to fractures. Example (metal-ceramic for high-stress areas): If an upper canine is the only contact in lateral excursion (canine guidance), a metal-ceramic crown is preferred for strength. If the tooth is part of a group function, a ceramic crown may suffice. Ensure opposing teeth contact either tooth tissue or the crown surface— not at the junction between the two. Example of Improper Planning: Ideal Treatment: A patient with Kennedy Class I and an extracted central Restore posterior teeth with a temporary RPD incisor receives a cantilever bridge on the lateral incisor. to provide support. Result: Bridge fractures due to excessive forces from Then, restore the anterior missing tooth to the absence of posterior support. distribute mastication forces. 1. Periodontal Support: Ratio of root length supported by alveolar bone to the length of the remainder of the tooth. 2. Root Length Crown-Root Ratio: Ideal ratio: 1:2 Optimum ratio: 2:3 Acceptable ratio: 1:1 Ratio >1:1 (longer crown than root) indicates the need for extraction.  ✅ ❌ General Guidelines for Post Length Conventional Rule: The post length should not be less than the length of the artificial crown. => Modern Approach: Make the post as long as possible without: - Disturbing the apical seal. - Risking perforation in a curved or tapered root. Variations in Post Length 1 Shorter Posts: Acceptable in cases of reduced occlusal forces (e.g., incisors with anterior open bite). Longer Posts: Necessary for teeth subjected to excessive forces (e.g., partial denture abutments). Improved Retention Strategies g Threaded Parallel Posts: Provide enhanced retention when adequate post length is unavailable. Gold Diaphragm & Collar: A full diaphragm of gold over the root face, combined with a collar around the periphery, improves retention and reduces the risk of root fracture. Indications for Crowning 1. Badly Destructed Tooth: Not all root canal-treated teeth require crowning. Key Factor: The amount of remaining tooth structure after RCT. Guideline: Any posterior tooth with RCT & an MOD restoration requires a crown. 2. Aesthetics: Discoloration of an endodontically treated tooth is a common complaint. First Choice: Internal bleaching. If internal bleaching fails, crown placement is indicated. 3. Alignment of Teeth: When patients refuse orthodontic treatment for misaligned teeth, crowns can be used to correct alignment. Types of Diagnostic Wax-Ups Case Study: Closing a Diastema 1. Conventional Wax-Up: Scenario: pt’s with a diastema Traditional method and the (gap) want to close the space. foundation for understanding Guidelines: digital techniques. - Diastema ≤ 2 mm: 2. Digital Wax-Up: - Can be restored with a Derived from conventional restoration if the proportions are wax-ups but offers advanced esthetically acceptable. visualization and precision. - Diastema > 2 mm: Advantages - Restoration is not Visualization: Allows the recommended due to patient to see the final result disproportionate teeth and risk of before starting treatment. gingival overhang, compromising Temporary Index: Creates a gingival health. guide for temporary restorations, D - Treatment Options: giving the patient a preview of 1. Ortho. the final restoration. 2. Extraction followed by restoration with a bridge. Always use diagnostic wax-ups when esthetics are a primary concern to ensure patient satisfaction and avoid complications.  to provide space for the All-Ceramic Restorations: technician to adjust the dentin, Shade is more critical compared to PFM, as these enamel, and other effects restorations are fully esthetic. (e.g., staining, transparency). Patients paying extra for all-ceramic restorations expect exceptional esthetics and accuracy. Timing of Shade Selection Before Preparation: - Ideal for accurate shade selection since it considers both enamel and dentin. - Prevents errors caused by operator fatigue. After Preparation: - If shade selection is forgotten, use the contralateral teeth for reference. - Example: For upper central incisors, select shade based on upper lateral incisors, not lower central incisors (which are typically darker). 1. Assessing OVD: Evaluate if increasing OVD improves esthetics and function in cases of tooth wear (e.g., bruxism). 2. Temporary Adjustment of OVD: Use adhesive restorations (composites) to test for TMJ & esthetic compatibility. 3. Permanent Treatment: If temporary OVD is successful, proceed with crowns, bridges, or veneers. Technique: Use a night-guard sheet to place and cure composites accurately. Alternative: Hand-free technique, but less precise. Key Principle: Never judge the remaining tooth structure before removing caries. Remove existing restorations to evaluate remaining structure (panoramic x-rays are insufficient). If the remaining structure is insufficient: consider crown lengthening, post & core, or extraction.  Assessment: Evaluate the extent of damage to the broken-down tooth. Determine if sufficient tooth substance remains for crown preparation. Indication: If insufficient structure remains, the tooth must be built up using a pin-retained core or a post-retained core to ensure retention for the crown. Immediate post and core placement for anterior teeth prevents disturbance to the root filling and may reduce the need for further endodontic treatment. Timing of Cementation: Cement the post and core before apicectomy to maintain the apical seal and avoid complications. 2 Organized from most important to least important:  # Explanation: If a lower 4 is missing, -- - s the lower 5 (with similar root length and periodontal membrane area) can · Su. theoretically support it with a bridge.  Periodontal Surface Area (Ante's Law) N Less than Key Principle: - Root surface area of abutment teeth should be equal to or greater than teeth being replaced with pontics. Clinical Significance: - As a guideline, this principle is referred to as "Ante's Law." - Fixed bridges with short pontic spans have a better prognosis than those with excessively long spans. poor choice Root surface area of 2nd premolar (A₂p) + 2nd molar (A₂m) > 1st molar (A₁m) A₁p + A₂m = A₂p + A₁m AₐC + A₂m < A₁p + A₂p + A₁m * No, Ante’s Law is not always applied clinically because it: Focuses only on vertical forces, while masticatory forces include horizontal and rotational forces that negatively impact the supporting teeth. Additionally, factors such as reduced bone support & distribution of forces through proprioceptors in the PDL limit its practical application in clinical settings. The forces generated by natural teeth are 10 times greater than those experienced by a patient with complete dentures.  Distribution of Occlusal Forces: Scenario A: Scenario B: Scenario C: Normal dentition (teeth 5, 6, 7). Missing 6, replaced with a bridge High masticatory forces on the bridge. Each tooth equally bears the (5 and 7 as abutments). Proprioceptors signal the brain to reduce occlusal load (force = “x”). Forces on the pontic (6) are masticatory force, lowering total load from Proprioceptors in the PDL signal distributed as 0.5x to each 3x to 2x. the brain to maintain even distribution. abutment tooth (5 and 7). This mechanism explains why bridges can function even with reduced support, Clinical Insight: Patients often report reduced chewing making Ante’s Law less relevant. efficiency on bridge sides compared to natural dentition.  Clinical Notes Horizontal, rotational, or leverage forces have the worst & quickest detrimental effect on prostheses. -  ~ - - Cross-Arch Splinting (Stabilization): · Upper Arch: Increases vertical forces while Ideal for full-mouth rehabilitations reducing lateral and diagonal forces. with few abutments. Provides stability for periodontally Lower Arch: compromised teeth or minimal abutments. Mandibular movements and strong masticatory muscles (e.g., masseter, medial pterygoid) Avoids tipping or lateral mobility of the cause bone flexure. prosthesis by distributing horizontal forces across the arch. Cross-arch stabilization in the Prosthesis crossing the midline lower arch should only extend enhances cross-arch stabilization, which from one mental foramen to the is why unilateral RPDs are avoided. contralateral mental foramen (e.g., lower 4 to lower 4). Bridges posterior to lower 4 increase the risk of fracture and bone loss.  Maryland bridge Also called a resin-bonded or adhesive bridge Latched Bridge Support Over Conservation: Support is the top priority when designing bridges, even if it requires sacrificing tooth tissue. Example: For a missing canine, a 3-unit bridge may not provide sufficient support. The second premolar should also be used as an abutment to ensure stability and durability of the bridge. III (2) Considered last priority when planning bridge design, following support, conservation, and cleansability. Separated Crowns vs. Splinted Crowns: Separated (single) crowns are more aesthetic and easier to clean than splinted crowns (bridges). Key Questions for Abutment Assessment: 1. Endodontically Treated Teeth: Can they be used as abutments for bridges? 2. Periodontally Involved Teeth: Are they suitable for use as abutments? Special Considerations: Evaluate specific conditions for endodontically treated and periodontally involved abutment teeth to ensure suitability for bridge design. Follow the sequence Essential for determining factors that cannot be evaluated clinically: Crown-Root Ratio Extent of Caries Determine pulp condition: Reversible pulpitis. Irreversible pulpitis. Necrotic pulp. · Before evaluating a tooth as a bridge abutment.  General Guidelines: Direct/Indirect Pulp Capping: Not recommended for abutment teeth. Doubtful RCT Teeth: Must be retreated and reassessed before use as abutments. Key Questions: 1. Can an RCT tooth be used as an abutment? 2. Which is better: a sound tooth or an RCT tooth as an abutment? Answer: Criteria for Using RCT Teeth: (1) Assess the remaining tooth structure (both coronal and radicular). (2) If remaining structure is sufficient, the support provided by an RCT tooth is equal to a sound tooth. (3) Check for anatomical root length (e.g., short roots like lower laterals may limit suitability). Advantages of Using RCT Teeth: 1. Conservation of Sound Teeth 2. Allows use of cross-arch splinting Advantages of Sound Teeth: 1. Freedom to place the finish line anywhere on the sound tooth. 2. Avoids placing finish lines on restorations, which may require subgingival positioning. d M  X The risk of using a tooth as an abutment exists for both sound and root canal-treated teeth but is reduced when part of multiple abutments in a larger bridge. Considered more conservative because it utilizes an already treated tooth instead of compromising a sound one...  Refers to the PDL root surface area (not anatomical root). Determines how much root is embedded in bone, influencing support. · Surface Area ↑ Criteria for Using Periodontally Affected Teeth as Abutments Tooth must be periodontally stable. Crown-Root Ratio: At least 1:1 is acceptable. Mobility: Should not exceed Grade 1. Bone loss of 1/3 does not result in a 1/3 loss of support. The actual area of support (A) The height of the bone (H) The center of rotation (R) moves apically (R′) The lever arm (L′) increases Do not proceed with fixed prosthodontic treatment on teeth affected by active periodontal disease. 2: 1 X  Flexing refers to reversible distortion when pressure is applied. Key Factors Influencing Flexure: 1. Length: Greater length → Increased flexure. 2. Thickness: Greater thickness → Reduced flexure. X units thick —> 1 unit of deflection 1/2X —> 8 units of deflection Flexure vs. Length of Span: Directly proportional to the cube of the length. Flexure vs. Diameter of Connector: Inversely proportional to the cube of the diameter. Examples: Doubling the number of pontics increases flexure 8 times. Reducing the connector height by half increases flexure 8 times. Example: For missing 4 and 5, use the canine, 6, and 7 as abutments to enhance support. Use metal for posterior bridges Increase occluso-gingival and or monolithic zirconia for reduced flexure. bucco-palatal thickness Avoid layering bridges with multiple materials.  Secondary Abutment - under tension > - primary Abutment acting as fulcrums ↳ primary 115(1) 858 Bone Lossou  Decementation 2 Soft tissue trauma, pain, and redness due to pontic flexure. 3 Best Design: A 3-unit bridge is ideal for replacing a single missing tooth. Exceptions: Missing lateral incisor: Requires different considerations. Missing canine: Requires a minimum of a 4-unit bridge for adequate support. Missing lower incisor: May not provide sufficient support for a 3-unit bridge. Contraindications: High occlusal forces and lateral excursions (excessive side movements) make cantilever bridges unsuitable. Assessment for Suitability: 1. Maximum Intercuspation: Ensure no impingement of opposing teeth in the pontic area. 2. Lateral Excursion: Check for lateral forces. If present, lateral forces directed on the pontic lead to bridge failure.  * D & D  Clinical Examples of Cantilever Bridges 1. Missing 4 or 5 (First or Second Premolar): If 4 is missing, use 5 and 6 as retainers to avoid preparing the canine. Preserves the canine’s role in esthetics and occlusion guidance. If 5 is missing, use 6 and 7 as retainers to distribute lateral forces. 2. Missing Distal Abutments (6 & 7): Use a cantilever bridge with 2 retainers to prevent overeruption of upper teeth. Pontic size: Half the original size of the 6 to minimize forces. Flatten pontic cusps to reduce lateral forces. Reducing Lateral Forces in Cantilever Bridges 1. Positioning the Occlusal Load: Place the occlusal load as far as possible from the abutment. Example: For a distal abutment, position the load on the mesial side of the pontic. 2. Flattening Pontic Cusps: Reduce the steepness of cusps to minimize lateral forces. 3. Using Double Abutments: Employing two abutments provides better distribution of forces and increases bridge stability. Clinical Solutions: (A) Partial Coverage Crowns (Modified Preparation Designs): With Elective/Intentional Endodontic Treatment Examples: 3/4 crown or 7/8 crown. Indication: Suitable for mesially tilted molars to align with the tilt while preserving the pulp and minimizing over-reduction. Advantages: Conserves tooth structure. Shortcomings: - Reduced preparation area decreases retention. - Increased risk of secondary caries due to cement dissolution. (B) Non-Rigid Connectors (Attachments): Definition: Connectors with one rigid part and one mobile part, used to align tilted abutments with the bridge. Design: - Intra-coronal attachment: Key-lock system used within the crown. - Steps: 1. Crown is cemented on the well-aligned tooth. 2. Pontic segment (with the key) is inserted into the key-lock of the tilted tooth and cemented. Advantages: Accommodates the misalignment of the tilted molar. Disadvantages: - Cost: Expensive materials. Telescope - Precision: Requires precise lab work. crown & - Durability: Friction over time may lead to corrosion and loosening. coping (C) Orthodontic Uprighting: Procedure: Upright the mesially tilted molar using orthodontic appliances, Follow up with a conventional bridge. Advantages: Safest and most effective option. Disadvantages: Time-consuming, Often refused by older patients. Definition: A pier abutment is a lone-standing abutment located between two edentulous areas. Example: A missing 4 and 6 with the 5 acting as the pier abutment. Challenges with Pier Abutments: 1. Physiological Tooth Movement: Teeth move differently depending on factors like the number of roots and bone support. This causes uneven stress distribution. 2. Fulcrum Effect: The pier abutment becomes the fulcrum between the resistance arm and the effort arm. Increased forces on the pier abutment lead to: - Fracture of connectors. - Mobility of abutment teeth. - Fracture of porcelain. 3. Complications in RPD or FPD: The biomechanical system stresses the lone-standing abutment, making treatment planning more complex. - Design: Divide the bridge into two segments: (1) Anterior segment: 3. Implant Placement: Fixed-fixed design including the pier abutment. Place an implant in an area (2) Posterior segment: with sufficient bone support. Fixed-movable design. Create a bridge on the Advantages: weaker side to reduce stress Reduces stress on the pier abutment. on the pier abutment. Aesthetic priority is maintained in the anterior segment. Design: Combine fixed-fixed and fixed-cantilever designs. Example: If the lateral incisor and 4 are missing: cantilive - - Use a fixed-fixed bridge to restore the 5. - Add a cantilever to replace the lateral incisor. Advantages: Maintains functionality while including the pier abutment in the bridge. Canine Replacement - Problem: - Bridges replacing canines are always difficult because the canine often lies outside the interabutment axis. - Maxillary Canine: - A bridge replacing a maxillary canine is subjected to more stress compared to mandibular replacements. - Forces are transmitted outward (labially) on the maxillary arch, which acts on the inside of the curve (the weakest point). - Mandibular Canine: - In the mandible, forces are directed inward (lingually) against the outside of the curve (the strongest point). Canines are the strongest anterior teeth and are surrounded by weaker teeth: Lateral Incisor (weakest anterior tooth). First Premolar (weakest posterior tooth). 3-Unit Bridges for Canines: Contraindicated due to insufficient support. Instead, a 4-unit bridge is recommended. Missing Canine, 4, and 5: FPD is contraindicated. Indicated solutions: RPD or implant.  Abutment Selection: Options: - (2, 4, and 5). - (1, 2, and 4). Choice depends on aesthetics: - If the central incisor is sound, avoid preparation to maintain aesthetics near the midline. - Use posterior abutments instead. - If the central requires a crown, it can serve as an abutment. Adjusting Occlusion: 1. Occlusion Type: If canine-guided occlusion is present, change to group function to redistribute forces away from the pontic area. 2. Force Direction: Upper Canine Replacement: Labio-palatal forces increase stress on the pontic area. Lower Canine Replacement: Forces are directed toward the ridge, which is more favorable but adjacent abutments are weaker.  Maintaining aesthetics is more complex for the upper anterior teeth. Upper teeth are not aligned in a straight line like the lower teeth. Upper anterior teeth face high tipping forces due to overbite & lateral forces. Anterior guidance causes significant labial forces on upper teeth. Lower anterior teeth have better biomechanics and smaller incisors, which distribute forces more evenly. For multiple missing lower incisors, a 6-unit bridge is indicated using the canines as abutments. Special Cases: If one central or lateral incisor remains and serves as a lone abutment: - Perform intentional extraction to avoid complications (e.g., irreversible pulpitis or fracture). Consider an adhesive bridge: - Most suitable when centrals are missing, and biomechanics are favorable. - Contraindicated in cases of deep overbite.  For multiple missing upper incisors, an 8-unit bridge is required, using canines and first premolars as abutments. ↳ Special Indications for a 6-Unit Bridge: (1) Reduced Overbite: In cases like Class III (edge-to-edge/reverse bite) or open bite, there are no anterior forces. (2) Class II Division 1: Increased overjet eliminates anterior guidance; posterior teeth control guidance. (3) Opposing RPD or CD: Removable prostheses exert less force than natural teeth, reducing strain on the bridge.  M Emergency Treatment: Address the patient’s primary complaint or emergency first before creating a comprehensive treatment plan. Start with treatments requiring the most healing time I 2 3 Y 5  ⁉ ⛔ Full Mouth Rehabilitation: Anterior Teeth First: Focus on anterior guidance as it determines posterior occlusion. Adjust anterior guidance to avoid: - Open bite caused by shallow anterior overlap and high posterior cusps. - Excessive anterior load due to shallow posterior cusps and deep anterior overlap. - Sequence: (1) Prepare and restore anterior teeth first (temporary and final restorations). (2) Posterior teeth restoration follows based on anterior guidance. Bilateral Posterior Bridges: Simultaneous or Sequential Approach: If strategic abutments (e.g., canines, first molars) affect occlusion: - Restore and cement one bridge before starting the other. - Example: Restore right side first, then left. For upper and lower arches: Start with one side (right or left) and then move to the opposite side. Temporary restorations cannot guarantee preservation of occlusion, especially during long treatment periods. Altering Occlusion or Vertical Dimension: If maximum intercuspal relation (MIP) or occlusal vertical dimension (OVD) needs adjustment: - Prepare all teeth simultaneously to fix OVD and MIP. - Avoid risks of: (1) Losing the index or temporaries wearing out. (2) Resulting occlusion complications.