Prosth Long Answers

F1 FullMetalCrowns

what are the advantages and disadvantages of full metal crowns

Advantages	Disadvantages
Longevity	Aesthetics
Resistance
Conservative
Adjustability
ideal for short clinical crowns

what are the indications and contraindications for full metal crowns

Indications	Contra indications
short clinical crown	high esthetic need
Maximum reterntion and resistance needed
High displacement forces
Situations requiring high strenght and durability
cases with limited occlusal clearance where more conservative reduction is necessary
Patients who are heavy bruxers, as god wears at a rate similar to natural tooth enamel and is less likely to fracture or wear the oppsoing dentition

what are the preparation indications for full metal crowns

Feature	Measurement	Rationale
Occlusal
Non-functional cusp	1.0 mm	This includes the buccal cusps of maxillary teeth and the lingual cusps of mandibular teeth.
Functional cusp	1.5 mm	This includes the palatal cusps of maxillary teeth and the buccal cusps of mandibular teeth. These areas bear the most occlusal force and require greater material thickness.
Axial	1.0 mm	Two planes of reduction are necessary on the buccal and lingual surfaces to accommodate the tooth’s natural contour while maintaining an ideal path of insertion.
Margin	chamfer > 0.5 mm	A chamfer margin is the standard for all-metal crowns. It is a conservative margin that provides sufficient bulk for the metal without requiring the aggressive reduction of a shoulder margin used for ceramics.

What kind of margin is used for full metal crowns? Why?

• chamfer margin is standard for all-metal crowns
  • it is a conservative margin that provides sufficient bulk for the metal without requiring the aggressive reduction of a shoulder margin used for ceramics

What are theoperative steps for metal crown prep?

1. Anesthesia: Administer local anesthetic. Even for endodontically treated teeth, anesthesia is often required for patient comfort during soft tissue manipulation (e.g., placing retraction cord).
2. Opposing Arch Impression: Take an impression of the opposing arch while waiting for the anesthetic to take effect.
3. Silicone putty index
4. Occlusal reduction
5. Buccal & lingual axial reduction
6. Interproximal reduction
7. Finishing
8. Auxiliary retentive features
   • types : vertical grooves or boxes

F2 Ceramics

When do you use each composition of metal ceramic?

Composition Type	Specific Examples/Materials	Indications (Clinical Situations)
Polycrystalline Ceramics	Zirconia (Zirconia Dioxide)	Used for a wide variety of indirect restorations such as crowns and bridges. High-strength material (flexural strength 900–1200 MPa). High translucency zirconia is now available.
Glass-Based Ceramics	Feldspathic Ceramics	Used as a monolithic ceramic for single-unit anterior prostheses, veneers, inlays, or onlays. Highly aesthetic due to high glass content.
Glass-Based Ceramics (with crystalline fillers)	Leucite Reinforced Glass Ceramics	Generally possess good aesthetic properties. Usually processed via “hot pressing”.
	Lithium Disilicate Reinforced Glass Ceramics (e.g., IPS Emax CAD)	Suited for single unit anterior crowns due to good flexural strength (360–400 MPa). Also used for occlusal onlays.
	Zirconia Reinforced Lithium Silicate (e.g., VITA Suprinity)	Has a high flexural strength (460 MPa).
Resin Matrix Ceramics (Hybrid)	VITA Enamic	Can be used for posterior and anterior crowns. These materials are not brittle and have good shock-absorbing characteristics due to the polymeric matrix.

What are the different compositions of ceramic?

Ceramic Category (by Composition)	Specific Materials / Examples	Common Processing Method(s)	Etchable with HF Acid?
Glass-Based	Feldspathic ceramics (pure or leucite-reinforced)	Powder/Liquid “Slurry”	Yes
Glass-Based (with crystalline fillers)	• Leucite reinforced (e.g., IPS Empress CAD) • Lithium disilicate (e.g., IPS Emax CAD) • Zirconia reinforced lithium silicate (e.g., VITA Suprinity)	• Hot Ceramic Pressing (for leucite and lithium disilicate) • CAD/CAM (milling)	Yes
Glass-Infiltrated	(e.g., VITA In ceram Alumina, Spinell, Zirconia)	Slip Casting	No
Polycrystalline	• Alumina • Zirconia	CAD/CAM (milling of pre-sintered or fully sintered blocks)	No
Resin Matrix Ceramics (Hybrid)	• Nanoceramic particles in a polymer matrix • (e.g., Lava Ultimate, VITA Enamic)	CAD/CAM (milling); does not require firing	Yes (e.g., Enamic)

F3 Temporizations

What are the advantages and disadvantages of each kind of temporary fabrication method (direct, indirect, direct-indirect)

Method	Advantages	Disadvantages
Direct	- Can be completed in a single visit. - Eliminates need for separate impression of prepared tooth for lab.	- Technique-sensitive. - Potential for pulpal irritation from exothermic heat and monomer release (e.g., with PMMA). - Fit can be compromised due to polymerization shrinkage.
Indirect	- Superior mechanical properties. - Patient not exposed to uncured monomers (allergies). - No heat from polymerizing resins. - Better fit and finish/polish. - Less clinical time. - Incorporates wax-up modifications. - Possibility of metal reinforcement. - Allows use of materials not suitable for direct intraoral use (e.g., heat-cured PMMA).	- Time-consuming (lab turnaround time). - Additional cost. - More suitable for extensive, long-term restorations.
Direct-Indirect	- Superior mechanical properties. - Better finish and polish. - Incorporates wax-up modifications.	- Additional laboratory cost. - More time-consuming than indirect technique (shells may need adjustment).

What are the biological, mechanical and esthetic factors of temporization?

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What are the biological, mechanical and esthetic factors of temporization?

Biological Factors:

• Pulpal Protection: Prevents thermal, chemical, and bacterial irritation to the pulp.
• Periodontal Health: Maintains gingival health by providing proper contours and smooth margins, preventing food impaction, and allowing for easy hygiene.
• Positional Stability: Prevents migration of adjacent or opposing teeth, maintaining occlusal and interproximal contacts.
• Biocompatibility: Materials should not cause allergic reactions or toxicity to surrounding tissues.

Mechanical Factors:

• Strength and Durability: Must withstand occlusal forces and remain intact until the definitive restoration is placed.
• Retention: Must be securely seated on the prepared tooth to prevent dislodgement.
• Occlusal Function: Should replicate the occlusal scheme to allow for comfortable mastication and prevent trauma.
• Wear Resistance: Should resist wear over the period they are in the mouth to maintain occlusal and interproximal contacts.

Esthetic Factors:

• Appearance: Should match the natural dentition in shade, shape, and contour, especially in the anterior region.
• Patient Comfort: Should be smooth and well-polished to avoid irritation to the tongue and oral tissues.
• Phonetics: Should not interfere with speech. </smtcmp_block>

What are all the different kinds of Temporary Materials?

Temporary Crown Materials Summary

Feature	Polymethyl Methacrylate (PMMA)	Polyethyl Methacrylate (PEMA)	Bisacryl Composite Resin	Light-Cured Composite Resin
Strength / Durability	High strength	Moderate strength; Weaker than PMMA	Brittle	Brittle
Exothermic Reaction (Heat)	Highly exothermic	Less exothermic than PMMA; Minimal heat increase (compared to PMMA)	Low exotherm	Controlled setting (light-cured)
Polymerization Shrinkage	Significant	Susceptible; Low shrinkage	Minimal	Not specified in notes
Aesthetics & Color Stability	Good color stability; Can be characterized	Prone to discoloration; Can be characterized	Can be smoothed and polished; Good for shade matching	Highly aesthetic; Can be characterized
Ease of Repair	Easily repaired	Easily repaired	Difficult to repair	Can be used to repair margins of Bisacryl crowns
Cost	Low cost	Low cost	High cost	High cost
Primary Indications	Laboratory construction (indirect); Long-span provisionals	Direct method for single crowns; Short-span bridges; Relining shells **used to line polycarbonate crowns and metal crowns **	Direct method for single crowns or short-span bridges; Ideal for matrix/template use	Direct method for single units; Inlays, onlays, and veneers; Repairing Bisacryl margins; **Used to line acetate crowns **

Link to original

Cements include :

• ZOE
• Eugenol-free
• Polycarboxyalte
• Tempbond clear

F4 Digital Impressions

what are the aims of a dental impression?

A digital impression directly creates a positive digital image display of intraoral anatomy. This eliminates the need for an intermediate pouring step required with conventional (negative) impressions, as it directly results in a 3D model used for fabrication or as a permanent record.

What are the advantages and disadvantages of intraoral scanners, can they be used for whole arch scans?

Category	Advantage	Disadvantage
Workflow	Streamlined process, immediate digital record, eliminates physical impression steps and lengthy disinfection.	Requires learning new techniques.
Patient Experience	Better patient tolerance (less gagging), allows scanning pauses without restarting.	Requires a shift in clinical mindset.
Time	Faster impression acquisition (e.g., under 60 seconds for a full arch with experience).
Financials	Long-term savings by eliminating material, tray, and shipping costs despite high initial investment.	Significant upfront costs for scanner, software, and hardware; potential resistance from clinicians to change established workflows.
Collaboration	Easier communication and collaboration with labs and other professionals.
Record Keeping	Secure cloud storage, eliminates physical casts, enables quantitative monitoring of dental changes.
Accuracy		Can be a concern in specific clinical situations despite generally high accuracy.

What are the most crictical factors for clinical success with intra oral scans

• Accuracy (ex. trueness and precision)

F5 Principles of tooth prep

What are the Biological , Mechanical and Aesthetic Principles of tooth preparation

IOLOGICAL

• 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

What is the clinical work flow for preparing and seating a crown

Workflow[^12][^13][^14]

Understanding the overall workflow helps contextualize the principles of tooth preparation.

1. Examination & Treatment Planning:
   • Includes clinical exams, pulp testing, radiographs, and diagnostic impressions to create mounted study models on an articulator.
   • This phase determines the prognosis and confirms the need for a crown.
2. Tooth Preparation & Temporization:
   • The tooth is reduced according to the principles for the chosen material.
   • A temporary crown is placed to protect the prepared tooth, prevent sensitivity, maintain occlusal and proximal contacts, and provide aesthetics.
3. Impression / Digital Scan:
   • Conventional: A definitive impression is taken using a material like PVS. The lab then pours a model.
   • Digital: An intraoral scanner (e.g., TRIOS) is used to create a digital model directly, or the conventional impression/model is scanned by the lab.
4. Laboratory Fabrication:
   • Conventional Workflow: A lab technician waxes up the crown by hand, casts it (for metal/PFM), applies porcelain, and finishes it.
   • Digital (CAD/CAM) Workflow: The crown is designed on a computer (Computer-Aided Design) and then milled from a block of ceramic or other material (Computer-Aided Manufacturing). It is then sintered, finished, and glazed.
5. Try-in and Evaluation:
   • The temporary crown is removed, and the definitive crown is tried in.
   • Key aspects are evaluated: interproximal contacts, occlusal contacts, marginal fit, shade, and shape.
6. Cementation:
   • If the try-in is successful, the crown is permanently cemented. Excess cement must be meticulously removed.
7. Review: The patient should be reviewed to ensure proper function and health of the surrounding tissues.

What are all the different kinds of margins, what are their indications?

Margin Type	Advantages	Disadvantages	Indications	Notes
Feather edge	Conservation of tooth structure	Fail to provide adequate bulk at margins; indistinct finish line, difficult for lab to read/fabricate	Generally contraindicated for crowns; may be used for some feldspathic veneers.	CONTRA-INDICATED IN MOST CASES!
Bevel	Allow margin of crown to be burnished against tooth structure; protect unprepared tooth from chipping; may reduce marginal discrepancy (for complete crown, not oversized)	Can lead to subgingival extension	Commonly for cast restorations.	Helps remove unsupported enamel.
Shoulder	Easy to prepare and finish well; easy to judge on impressions	More aggressive preparation	Primarily for all-ceramic crowns; can be used for all materials.	Prepared with a flat-end bur, resulting in a rounded internal line angle.
Chamfer	Conserves tooth structure while providing distinct finish lines; easy to read in impressions	-	Commonly used for metal or ceramic crowns.	This is the most common margin type. Use a tapered diamond bur with a round tip!
Shoulder with bevel	-	Poor aesthetics and potential violation of biologic width (when historically used for PFM to hide metal collar subgingivally)	Sometimes used for PFM crowns with a metal labial margin (hidden in the sulcus); uncommonly used.	Historically used for PFM crowns where a metal collar at the margin was hidden subgingivally for a better seal. Not preferred today. A shoulder/chamfer is preferred for biologic and aesthetic considerations. Often considered an “uncommon” choice today.

F6 Soft Tissue Impressions

What are the three objectives for an impression

1. Exact duplication of the prepared and uncut tooth beyond the preparation to allow evaluation of location and configuartion of finishing line
2. Duplicate other teeth and soft tissue to permit proper articulation of the cast and contouring the restoration
3. must be free of bubbles specially at finishing line and prepared surfaces

How to determine biological width

• Bone sounding:
  • press the perio probe down until you hit bone
  • measure just the sulcus depth bfore hand
  • subtract sulcus depth from bone sounding
  • all good if hte measurement is greater than 2 mm

What are the types of bone crest?

• Normal (85%) gingival margine to bone = 3-4.5
• HIgh creast (2%) = measurment is less than 3 mm
• Low creat (13%) = measurement is greater than 4.5 mm

Explain the Gingval retraction technique for subgingival margins

• Find the smallest retraction cord that ifrst nad put i in first
  • the smellest one i.e.e 00
  • You want to make sure it clears the margins of teh crown
  • you want the impresison material to go into the gingival sulucs
• Then find a second larger retraction cord
  • leave it in for 5 minuts
  • then you can take it and and the difference should be bigger!

What are the various methods of gingival displacement

• Mechanical
  • retraction cord and copper band
• Chemical
  • Astringent: aluminium choride, ferric sulfate
  • Adrenaline
• Combined
  • retraction cord + chemical
  • Expasyl (kerr)
    • Aluminin chlroide with kaolin clay
• Surgical widening
  • electrosurgery
  • laser

What are the materials used for indirect restorations

- PVS 
- Poly Ether 
- PVs is superior to polyether 

What are the main impression techniques

• Single STage
• Two stage
  • spacer or no space

What to look for when inspecting an impression?

• Detailed, accurate occlusla surfaces
• Distal surfaces of molars are captured
• No bubbles, voids , thin walls, shifts or double imprings that compromise dental anatomy
• all gingival margins are defined and clear
• uniform layer of material

F7 Cements

What are the two main ways that permanent cements can be classified?

• Composition
  • resin vs water based
  • Compomers
• Bonding mechanism
  • non-adhesive luting
  • micromechanical retention
  • molecular adheison

How do Luting Cements work

• by friction (imagine two pieces of sand paper )

What is a traditional luting cement

Zinc phosphate

How do Micromechanical bonding cements work?

• Resin cements through etching dentin/enamel
• Trhough etching glassy ceramics (HF acid)
• Sand blasting metal/zirconia cowns

How do molecular adhesion cements work?

• physical forces such as Van der waals or chemical ionic bonding
• 10- mdp
  • at the moment cements still requie other methods of ternention (like parallel walls) and we can’t rely solely on this

What are the ideal Properties of Cements?

• Low film thickness
• Suitable working time and setting time
• High compressive strength
• Similar elastic modulus as denitn
• Biocompatible
• Plaque/caries inhibition
• low solubility
• low microleakage
• Easy removal of excess
• high retention

How does film thickness affect bond strength

• lower the film thickness, the higher the bond strength!

Name the different types of Dental Cements

Summary Table of Dental Cements

• zoe
• zINC PHOSPHATE
• Zinc polycarboxylate
• GIC
• RMGIC
• Resin Based
  • PANAVIA
    • resin cement iwth bifunctional monomer 10mdp

Name the various cement brands and the differences between them

Summary Table of Cements

Cement Type	Use Cases (Restoration Type)	Key Composition/Mechanism	General Protocol Highlights
Variolink Esthetic	- Glassy ceramic crowns (e.g., Lithium Disilicate - IPS e.max) - Requires strong adhesive bond	- Resin-based (similar to restorative composite) - Requires etching and bonding to tooth and restoration surfaces	Extra-oral (Restoration): Clean, etch (HF acid for ceramic), silanate (Monobond Plus). Intra-oral (Tooth): Clean, optional phosphoric acid etch, apply adhesive (Adhese Universal), light cure. Cementation: Apply cement to crown, seat, tack cure, remove excess, final cure with Liquid Strip.
Panavia F 2.0	- Zirconia crowns - Metal crowns/PFM crowns - Resin-retained FPDs (with suitable preparation)	- Resin cement with MDP monomer - MDP-based chemical adhesion to metal oxides (zirconia, non-precious metals) and calcium in tooth - Dual-cure	Zirconia: Clean crown (e.g., sandblast), apply ED Primer II to tooth, mix & apply cement to crown, seat, remove excess (tack cure), final cure (light or self-cure with OXYGUARD II). Metal/PFM: Same as Zirconia, but apply Alloy Primer to metal surface after sandblasting.
RelyX Unicem 2	- Indirect restorations (crowns, bridges, inlays, onlays) - Root canal glass fibre posts	- Dual-curing, self-adhesive resin cement - Acidic monomers demineralize and infiltrate (no separate etch/bond step)	Clean tooth (avoid overdrying). Clean/pre-treat restoration surface (as needed for material). Dispense cement into crown, seat, tack cure, remove excess, final cure. No separate etching or bonding to the tooth is required.

F8 Try in

What are the five main steps in the clinical workflow for crowns

1. Assessment and treatment planning
2. Preparation and Impression
3. Try in and Evaluation
4. Cementation
5. Post operative review

Outline the preparation stage (step 2)

1. Before patient arrives
   • decide on material of choice
   • Approval of treatment plan
   • Wax up of tooth
2. Putt key fabrication
   1. create a putty key on a dental cast for easier fabrication of the provisional resto
3. Day of preparation
   • Confirm tx and anesthesize
   • pre-operative records
   • Shade selectoin
   • Tooth preparation
   • Check preparation
   • Provisional restoration
   • Impression
   • Temporization

What are the different methods of shade selection?

- Shade tabs 
	- vitapan classic 
		- 16 shades grouped by hu then chroma 
	- Vitapan 3D master 
		- Value group 
		- Chroma rows 
		- hue columns 
		- choose shade in that order ! 
- Digital Shade selection 
- Sending patient to lab

What is the systematic approach of the try-in procedure itself?

1. Evaluation of the crown on the die
   • Die and opposing model
   • internal surface of restoration
   • Restoration on the model (die)
2. Seating the crown on the prepared tooth
   • Proximal contact
   • internal fit
   • marginal fit
3. Assessment of the seated crowns
   • Stability
   • Contour
   • Occlusion
   • Aesthetics

M1 PFM

What are the indications for tooth preparation

• Restoration of teeth that have lost tooth structure by caries and non-caires lesions
• Preaprations of healthy teeth for aesthetics

what are the biological mechanical and aesthetic factors for tooth preparation

• biological
  • preservation of tooth structure
  • avoidance of overcontouring
  • supragingival margins
  • harmonious occlusion
  • protection against tooth fracture
• Mechanical
  • retention form
  • resistance form
  • sturctrual durability
• Aesthetic
  • minimum display of metal
  • maximum thickness of porcelain
  • porcelain occlusal surfaces
  • Subgingival marings

What are the 5 possible margin designs

1. Feather edge
2. Bevel
3. Chamfer
4. Shoulder
5. Shoulder with bevel

what are the advantages and disadvantage of each kind of margin design?

Circular transclusion detected: School/DMD2S2/DENT4216_Prosth/Prosth-Long-Answers

What are the two philosphies when it comes to maintaining occlusion

1. Confirmative approach
   • the resto is designed to fit into the patient’s existing occlusion iwhtout changing it
2. Reorganized approach
   • The entire occlusion is rebuilt, usually in complex cases of severe wear

What are the factors that retention form depends on:

1. Preparation height
2. Degree of taper
3. Freedom of displacement
4. Roughness of surfaces
5. physical luting cement

What does a natural looking restoration depend on

• Facial tooth reduction
• incisal reduction
• proximal reduction
• material selection
• substratum colour

M4 Optimal Occlusion

What are the pathological Adaptations to occlusion? What are their causes?

Pathological Adaptation	Key Clinical Signs / Description	Primary Cause(s)
Attrition	Tooth wear (e.g., incisors). Severe wear can lead to dentoalveolar compensation, limiting restorative space.	• Lack of posterior tooth support • Bruxism • Abrasive restorative material
Splayed Teeth	Anterior teeth move or flare out. Teeth are often sore before they move.	• Loss of posterior teeth combined with periodontal problems • Over-contoured restorations
Sore Teeth	Considerable pain on biting.	• Premature occlusal contacts (occlusal overload) • Occlusal interferences (e.g., a “high” restoration)
Sensitive Teeth	Pulp hypersensitivity (e.g., to cold) in the absence of decay.	• Occlusal overload • Restoration causing occlusal interferences
Hypermobility	”Wobbly” tooth; a protective mechanism to excessive stress. May show a widened PDL space on a radiograph.	• Occlusal overload • Deflective contacts or lateral interferences (often from a restoration)
Tooth Cracks	Crack lines on cusps; “Cracked Tooth Syndrome” presents as sharp pain specifically on biting down.	• Heavy occlusal forces loading a cusp • Occlusal overload
Painful Musculature	Soreness and fatigue in masticatory muscles.	• Deflective occlusal interferences causing jaw displacement • Unbalanced muscle contraction

What are two basic TMJ movements , what are the movement directions?

Movements - Hinge movement - rotatin around the intra-condylar axis - within the glenoid fossa - <2 cm of movement - Translation movement - Gliding against articular eminence - >2cm Movement directions:

• Protrusive movement
• Lateral movements
  • workig side: rotational movement around the vertical axis without leaving the glenoid fossa
  • non-working side: gliding movement against the articular eminence

M6 Onlays

What is an inlay, what is an onlay, whats the difference

• inlays: Fixed intracoronal restorations that fit within the anatomic contour of the clinical corwn
• Relies on the strength of the remaining tooth structure for support
  • does not protect the cusps and relies on them instead
• Onlays: Partial-coverage restoraiton that restores one or more cursps and adjoining occlusal surfaces, or the entire occlusal surfacs
  • when it covers the entire occlusal surface, the onlay can be referred to as a table top

What are the indications and contraindications of inlays, onlays?

Restoration	Indications	Contraindications
Inlay	* Moderate-sized cavities confined within the cusps. * Teeth with at least one sound marginal ridge. * Replacement of small defective restorations (e.g., amalgam or composite) in the occlusal area. * Cases requiring better marginal fit and durability than direct restorations. * When precise occlusal anatomy and contact points are needed, especially for deep proximal boxes to ensure stability and prevent periodontal issues.	* Extensive tooth destruction involving cusps. * Poor isolation or moisture control for bonding. * MOD cavities with weak cusps.
Onlay	* Large cavities involving one or more cusps, but with enough sound enamel remaining for bonding. * Teeth with fractured or weakened cusps that need protection. * Replacement of defective large restorations. * Restoration of endodontically treated teeth (which are structurally compromised) when sufficient tooth structure is present. * Situations where a full crown is too aggressive, and tooth structure can be conserved (e.g., preserving cervical tooth structure). * Replacement of large MOD amalgams for aesthetic reasons.	* Teeth that are severely compromised and lack sound enamel for predictable bonding (as bonding to dentin/cementum is less predictable). * Severe parafunctional habits (e.g., bruxism), which can fracture ceramic restorations.

When on the border, how to determine if to do an inlay or onlay?

• If the width of the occlusal isthmus is greater than half the distance between the cusp tips, the cusps are likely undermined and require onlay coverage for protection
• if the cusp wall is less than 2 mm
• low quality and unsupported enamel covering the cusp
• occlusal contacts on the margin of preparaiton

What is the gold standard in stress bearing restorations?

• CAD/CAM ceramic restorations

What are the main reasons for onlay failure?

• secondary caries, fracture, marginal deficiencies, wear and postoperative snesitivty

What are the various materials used

• Can have
  1. Precious alloys: Gold/Cast
  2. Indirect composite resin (polymer-based): CAD-CAM
  3. Ceramic
• The various survival rates are similar
• Deterioration : gold < ceramic < composite

Compare CAD/CAM polymer-based material with pressable lithium disillicate ceramic

Comparison of Dental Restoration Materials

Feature	CAD/CAM Resin Composites (Indirect)	Ceramics (General & Lithium Disilicate)
Edge Stability	Higher (permits very thin margins)	Lower (than CAD/CAM composites)
Homogeneity	More homogenous	Not mentioned
Abrasion Resistance	More resistant than direct composites, but less resistant than ceramics. Showed higher abrasion rates than lithium disilicate.	Generally superior to CAD/CAM composites. More resistant to abrasion than CAD/CAM resin composite.
Flexural Strength	Lower than ceramics	Generally superior to CAD/CAM composites
Discoloration Rate	Generally lower than ceramics, but showed significantly higher discoloration rates compared to lithium disilicate.	Generally superior to CAD/CAM composites.
Antagonist-Friendly	Yes. (Causes less wear on opposing teeth)	No. (Harder, less antagonist-friendly)
Repairability	Easily repairable in the mouth	Not mentioned
Long-Term Failure Rate	Higher (than pressed lithium disilicate)	Lower (than CAD/CAM resin composite)
Material Fractures	Exhibited more material fractures (compared to lithium disilicate)	Not mentioned
Survival Rate (clinical obs.)	100% (up to 13 years)	100% (up to 13 years)

Compare direct resins vs indirect resins?

Feature	Direct (Posterior) Composites	Indirect Composites
Polymerization	Incomplete polymerization	Complete polymerization (fabricated from a fully polymerized block)
Polymerization Shrinkage	Yes	No clinical shrinkage stress
Porosity	Not mentioned	Less porosity
Tooth Preservation	Pro: Maximum preservation (minimally-invasive)	Con: Less conservative
Cost	Pro: More affordable	Con: More expensive
Appointments	Pro: Single appointment	Not mentioned
Control of Contacts & Contours	Con: Technique sensitive (especially for tight contacts and ideal anatomy)	Pro: Better control
Marginal Adaptation & Bond	Con: Prone to microleakage	Pro: Better marginal adaptation and bond strength
Lifespan / Failure Issues	Con: Relatively short lifespan; microleakage, secondary caries, staining, fractures	Not mentioned
Chemical Degradation	Con: Degrade chemically in the oral environment	Not mentioned
Wear Resistance	Con: Lower wear resistance	Con: More wear (vs. ceramic)
Risk of Fracture	Con: Prone to fractures; relies on remaining tooth structure for strength	Con: More risk of fracture (vs. ceramic)
Color Stability	Con: Prone to staining	Con: Unpredictable (vs. ceramic)
Mechanical Properties	Con: Relies on remaining tooth structure for integrity	Con: Inferior (vs. ceramic)
Repairability	Not mentioned	Pro: Easier to repair (vs. ceramic)
Aesthetics/Functionality	Pro: Restores aesthetic and functionality	Not mentioned

What are the key preparation features for ceramic onlays and inlays

• No sharp internal line angles or points, only curver transitions
• The prep extensino depends on the extnesion of the previous restoration or the caries lesion
• All cavo-surface angles should be sharp an dwell defined
• Divergence : Greater than or equal to 10 degrees on buccal and lingual walls
• Convergence: 10-12 degrees of axial wall convergence
• No acute angles
• smooth flowing margins
• No additional retention features
• no tooth structure without suport
• obtuse external line angles

Where is the most aesthetic placement of buccal/labial marings

• incisal or cervical thirds

What are the most appropriate margins to use in inlays/onlays

• Deep chamfer, modified shoulder
  • can be supra or equigingival

Explain morphology driven preparation

• bonded restorations
• immediate dnetin sealing after tooth preps
• Deep margin elevation

What is the internal checklist before impression or scanning of an inlay/onlay

1. well defined sharp margins
2. no undercuts
3. smooth surface
4. accessibility to all margins, especially subgingival margins
5. Absence of contact between the prep margin and the adjacent tooth
6. adequate interocclusal space

What are the techniques of interim restorations of inlays/onlays?

1. Non-cemented “semi-rigid” light curing resin
   • telio
   • ivoclar
2. Self-curing material
   • Cavit W
3. Direct technique: Bis-Acryl composite