midterm 2025 review Flashcards
List the instruments to identify in the cassette.
- Explorer
- Mirror
- Perio probe
- Gingival marginal trimmer
- Spoon excavator
- Hatchet
- Condenser
- Different carvers
- Toffelmire retainers
- Universal matrix bands
- MOD matrix band
What are the parts of a dental instrument?
- Shaft/handle
- Shank
- Blade
What does the instrument formula describe?
The blade characteristics of the instrument.
What is the difference between the 3-number and 4-number formulas?
3-number formula describes width, length, and angle of blade; 4-number formula adds an angle of cutting edge.
What does the first number in a 3-number formula represent?
Width of blade in tenths of mm.
What does the second number in a 3-number formula represent?
Length of blade in mm.
What does the third number in a 3-number formula represent?
Angle of blade to long axis of the handle.
What are the benefits of stainless steel instruments?
- Resists corrosion
- Dulls easily
What are the benefits of carbon steel instruments?
- Corrodes
- Holds sharpness
What are diagnostic instruments used for?
To examine hard and soft tissues, diagnose caries, pathologies, etc.
What is the primary use of a spoon excavator?
To remove caries.
What is the purpose of hand cutting instruments?
- Removes loose enamel
- Removes caries
- Smooths preparation
- Refines cavity features
What is the function of a gingival margin trimmer?
To trim and smoothen preparations in the proximal box.
What is a bur in dentistry?
A rotary cutting instrument with bladed cutting heads.
What are the three parts of a bur?
- Shank
- Neck
- Head
What does the neck of a bur do?
Connects the head to the shank, transmits rotational and translational forces.
What is the purpose of the head of a bur?
To perform the desired shaping of tooth structure.
What are the basic shapes of burs?
- Round
- Inverted cone
- Pear
- Straight fissure
- Tapered fissure
What is dental caries?
A multifactorial, transmissible infectious oral disease caused by the interaction of cariogenic oral flora with fermentable dietary carbohydrates.
What are the main host factors affecting dental caries?
- Salivary flow rate
- Salivary composition
- Diet
What is the difference between infected and affected dentin?
- Infected dentin: Irreversible, denatured with bacterial invasion
- Affected dentin: Partially demineralized, vital, and remineralizable
What is the G.V. Black Classification of Caries?
A system to classify carious lesions based on location and severity.
What does Class I caries affect?
Pits and fissures on occlusal surfaces of molars and premolars.
What does Class II caries affect?
Proximal surfaces of molars and premolars.
What does Class III caries affect?
Proximal surfaces of central incisors, lateral incisors, and cuspids without involving incisal angles.
What is the cavosurface margin?
The junction of the wall with the external, uncut surface of the tooth.
What are the forms of tooth preparation?
- Outline
- Convenience
- Resistance
- Retention
What does outline form refer to?
The shape of the preparation.
What is resistance form in tooth preparation?
The shape given to the prep to prevent fracture of the restoration or the tooth.
What is retention form in tooth preparation?
The shape that prevents restoration from being displaced by tipping or lifting forces.
What is abrasion in dental terms?
Tooth surface loss from frictional forces.
What is erosion in dental terms?
Loss of tooth surface by chemicomechanical action.
What is attrition in dental terms?
Mechanical wear from opposing teeth.
What is abfraction in dental terms?
Cervical, wedge-shaped defects caused by strong eccentric occlusal force.
What is resistance form in tooth preparation?
Shape given to the prep to prevent fracture of either the restoration or the tooth
Resistance form considerations include placing the prep 0.5 mm into dentin to avoid sensitive DEJ, provide adequate bulk, and utilize dentin’s resilience.
What is retention form in tooth preparation?
Shape that prevents restoration from being displaced by tipping or lifting forces
Retention includes features like dovetails, undercuts, grooves, pins, and requires primary and secondary retention.
What is convenience form in tooth preparation?
Shape that allows the needed procedure to be performed
It facilitates vision, access, and ease of instrumentation and insertion of restorative material.
What are the steps of tooth preparation review?
- Outline form and initial depth
- Primary resistance form
- Primary retention form
- Convenience form
- Final tooth preparation stage
- Pulp protection
- Secondary resistance and retention forms
- Finishing procedures
Final procedures include cleansing, inspecting, and desensitizing.
What is the purpose of divergence of M and D walls in Class I prep?
To prevent undermining marginal ridge
Divergence creates an obtuse angle with the pulpal floor.
What are the ideal Class I preparation measurements?
- Pulpal floor 1.5-2mm
- Walls at 90 degrees to resist fracture
- Occlusal width 1/5-1/4 (1.0 mm) of intercuspal distance
All cavosurface margins should be at a right angle.
Fill in the blank: The ideal depth for Class I preparation is ______.
1.5 mm
What is the minimum thickness of restorative material required to resist occlusal force?
1.5 mm
Less than this may not resist occlusal force or fracture.
What is the diagnostic method for detecting decay?
- Visualize
- Tactile feel
- Radiograph
Use a dull explorer to avoid cavitation.
What is the outline form in tooth preparation?
Shape of prep
It includes all caries and defective pits/fissures.
What is the width of the isthmus for Class I preparation?
Contral portion of prep between mesial and distal aspects
For Class II, the isthmus is between 2 proximal flares.
What is the purpose of retention grooves in amalgam preparations?
To provide retention and prevent displacement
Required only for Class II restorations.
What are the steps for amalgam restoration placement?
- Activation
- Trituration
- Insertion
- Condensation
- Carving
Total working time is 10-12 minutes.
True or False: High copper amalgams reduce creep and tarnish.
True
What is the role of a wedge in dental procedures?
- Separates teeth
- Protects gingival tissue
- Seals matrix against gingival floor
It compensates for the thickness of the matrix band.
Define the term ‘finishing’ in dental restoration.
Process of removing surface defects created during contouring
This is done using cutting or grinding instruments.
What is the ideal distance from the operator’s eye to the patient’s mouth?
12-16 inches
What is the significance of proper operator positioning?
Facilitates lumbar curve and circulation to legs
The buttocks should be fully in the seat pan.
What is self-assessment in learning?
Self-directed learning where learners assess their own performance
It helps students develop specific learning skills for professional competence.
What is the recommended patient mouth distance during dental procedures?
12-16 inches
This distance is crucial for effective communication and procedure execution.
What is the operator’s position for right-handed operators?
11 o’clock or 8 o’clock position
The position varies based on the specific procedure being performed.
What is the operator’s position for left-handed operators?
1 o’clock or 4 o’clock position
This positioning facilitates better access and visibility.
How should the patient’s head be adjusted for the maxillary arch?
Patient raises chin
Elevating the chin provides better access to the upper teeth.
How should the patient’s head be adjusted for the mandibular arch?
Patient lowers chin to chest
Lowering the chin aids in accessing the lower teeth.
What constitutes a neutral body position for the operator?
Joints in normal, relaxed position, spine erect, neck slightly bent forward, arms and elbows at sides, forearms parallel to floor, wrists straight, thighs inclined 10-15 degrees, feet flat on floor
Maintaining this position reduces strain and enhances comfort.
Why should arms and elbows be positioned at the sides?
Reduces shoulder fatigue
Proper positioning helps maintain operator endurance during procedures.
What is the importance of maintaining neutral wrists?
Reduces stress causing carpal tunnel syndrome
Proper wrist alignment is essential for long-term hand health.
What is a proper instrument grasp technique to reduce hand fatigue?
Modified pen grasp
This grasp allows for better control and comfort.
What features should be considered in instrument design to enhance usability?
Light weight, hollow handles, large barrel handles, serrated grip (knurling)
These features improve grip and reduce hand strain.
What are the characteristics of an effective handpiece design?
Lightweight, short, low vibration, reduced drag
These characteristics contribute to operator comfort and precision.
Name some recommended hand and forearm exercises for dental operators.
Periodic stretching, exercise, relaxation hand strengthening exercises, hand grip strengthening, forearm stretch
Regular exercises help maintain flexibility and strength.
What is the standard of care for rubber dam placement?
Considered standard of care for endodontics
Rubber dams are essential for maintaining a dry working field.
What is the first step in rubber dam placement?
Prepare and encourage patient and yourself
Ensuring comfort and understanding is vital for successful dam placement.
What should be evaluated intraorally before rubber dam placement?
Tight contacts, missing teeth, mispositioned teeth
This evaluation ensures proper fit and function of the rubber dam.
What is the purpose of applying a ligature during rubber dam placement?
Dental floss tied to clamp for accessibility
This helps secure the clamp and prevent loss during the procedure.
Where should the clamp be placed relative to the tooth being worked on?
Distal to the tooth
This positioning provides better visibility and access.
What type of clamp should be used when not available?
Curved toward apex clamp
This allows for better adaptation to tooth morphology.
What is the standard practice for clamp bow positioning?
Bow positioned to distal for visibility
Proper positioning enhances access during the procedure.
