During countercurrent mechanisms, which of the following area of nephron does filtrate become hypertonic to plasma?

 # During countercurrent mechanisms, which of the following area of nephron does filtrate become hypertonic to plasma?
A. Bowman’s capsule
B. Proximal convoluted tubule
C. Loop of Henle
D. Distal convoluted tubule

The correct answer is C. Loop of Henle.

A circuit of fluid in the loop of Henle—an important part of the kidneys—allows for gradual buildup of the concentration of urine in the kidneys, by using active transport on the exiting nephrons (tubules carrying liquid in the process of gradually concentrating the urea). The active transport pumps need only to overcome a constant and low gradient of concentration, because of the countercurrent multiplier mechanism.

Piggyback technique in Orthodontics

 Sectional NiTi wires can also be used to align a malpositioned tooth in a piggyback manner where rest of the arch is ligated with a stiff wire. With this arrangement, a light continuous force is exerted to bring the displaced tooth into the alignment while reciprocal force is distributed over the anchor teeth. 

Case done by: Dr. Sushant Pandey, CODS BPKIHS

Piggyback wires offer the potential to combine wires of similar or, more commonly, markedly different physical properties. In relation to space redistribution and alignment, piggybacks typically involve use of flexible round NiTi wires in combination with more rigid base arch wires permitting alignment of displaced teeth limiting the effect of reactive forces in terms of horizontal and vertical anchorage. 

1. Kharbanda, Om. (2013). Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities 2nd ed.. 
2. Fleming, P., Seehra, J., 2019. Fixed Orthodontic Appliances. BDJ Clinician’s Guides..

Creating the Perfect Smile: The Art and Science of Dental Clinic Interior Design

 The atmosphere within a dental clinic plays a pivotal role in shaping patients' perceptions and experiences. Dental professionals recognize the importance of creating a welcoming and comfortable environment that goes beyond the clinical aspect of oral care. The interior design of a dental clinic is an art and science that seamlessly combines aesthetics, functionality, and the unique needs of the dental practice. Let's delve into the key considerations that make dental clinic interior designing an essential aspect of the overall patient experience.

1. Balancing Functionality and Aesthetics:
Dental clinics require a careful balance between functionality and aesthetics. The layout should be designed to optimize workflow for dental practitioners while providing a warm and inviting atmosphere for patients. Well-designed reception areas, consultation rooms, and treatment spaces contribute to a positive overall experience.

2. Patient Comfort and Relaxation:
Dental anxiety is a common concern among patients. Interior designers focus on creating spaces that alleviate stress and promote relaxation. Comfortable seating, soothing color schemes, and ambient lighting all contribute to an environment that helps patients feel at ease.

3. Ergonomics for Dental Professionals:
The efficiency of dental practitioners is directly influenced by the ergonomics of the workspace. Interior designers collaborate with dental professionals to ensure that treatment rooms are designed to support optimal working conditions. This includes considerations for equipment placement, lighting, and accessibility.

4. Technology Integration:
Modern dental practices rely on advanced technologies for diagnosis and treatment. The interior design should seamlessly integrate these technologies into the clinic's aesthetic. Concealed wiring, strategically placed outlets, and designated spaces for digital displays contribute to a streamlined and contemporary look.

5. Infection Control and Hygiene:
Maintaining a sterile and hygienic environment is paramount in dental clinics. Interior designers work closely with dental professionals to select materials that are easy to clean and resistant to bacteria. Design choices should facilitate efficient infection control practices without compromising on visual appeal.

6. Branding and Identity:
The interior design of a dental clinic serves as a visual representation of the clinic's brand and identity. Consistent color schemes, logo placement, and branded elements create a cohesive and recognizable image that reinforces the clinic's professionalism.

7. Accessibility and Inclusivity:
Dental clinic interiors should be designed with accessibility and inclusivity in mind. This involves considerations for individuals with mobility challenges and the implementation of universal design principles to ensure that everyone, regardless of physical abilities, can access and navigate the space comfortably.

In conclusion, dental clinic interior designing is a multidimensional endeavor that goes beyond choosing colors and furniture. It involves a thoughtful integration of functionality, patient experience, and the unique needs of the dental practice. A well-designed dental clinic not only fosters a positive environment for patients but also enhances the efficiency and effectiveness of dental professionals. As the field of dentistry evolves, so too does the art and science of dental clinic interior design, creating spaces that truly reflect the commitment to oral health and patient well-being.

MCQs in Operative Dentistry - Dental Cements

# The preferred agent for base formation below restorative resin is:
A. Calcium hydroxide
B. Cavity varnish
C. Zinc oxide-eugenol cement
D. None of the above

# Dentin protection during cavity restoration is most important when the "remaining dentin thickness" is:
A. 1 - 2mm
B. 1.5 mm
C. 0.5 - 1mm
D. 0.5 mm

# Cavity varnish is indicated under amalgam restorations to:
A. Prevent galvanic currents from reaching the pulp
B. Improve the marginal seal of the restorations
C. Seal the dentinal tubules completely
D. Act as an effective thermal insulator

# Calcium hydroxide is preferred to ZOE fillings below a composite resin restoration as:
A. Calcium hydroxide forms a calcific bridge
B. Eugenol irritates the inflamed pulp
C. Eugenol interferes with the setting of composite resins
D. None of the above

# When using the acid etch technique to restore a Class IV fracture, exposed dentin should first be covered with:
A. Cavity varnish
B. Phosphoric acid
C. A calcium hydroxide liner
D. Zinc oxide-eugenol cement

# Which of the following bases are contra indicated under a composite resin restoration?
A. Calcium hydroxide
B. Eugenol base
C. Zinc phosphate cement
D. None of the above

# Cements in dentistry can be used as:
A. Liners
B. Bases
C. RC fillers
D. All of the above

# Cavity varnish is used for:
A. To reduce thermal conductivity
B. To reduce the permeability of acid into dentinal tubules
C. Action as an obtundant
D. All of the above

# Amount of gap required for cement in restoration is:
A. 10-25 microns
B. 2 microns
C. 50-100 microns
D. No gap required

# Copal varnish is:
A. ZnO resin
B. Ca(OH)2
C. ZnO glycerin
D. All of the above

# Amalgam often tends to discolor the teeth. This can be inhibited by using:
A. A zinc free alloy
B. An alloy containing zinc
C. Calcium hydroxide on the pulpal floor
D. Cavity varnish on all cut surfaces

# Fluoride rich materials include:
A. Silicate cement
B. Glass ionomer cement
C. Polycarboxylate cement
D. All of the above

# Glass ionomer cements are composed of:
A. Alumino silicate powder and phosphoric acid
B. Alumino silicate powder and polyacrylate liquid
C. Zinc oxide powder and phosphoric acid
D. Zinc oxide powder and polyacrylate liquid

# Which one of the following dental cement accelerates the formation of reparative dentin?
A. Eugenol
B. Calcium hydroxide
C. Zinc oxide
D. Silica

# Minimum thickness for type-I zinc phosphate cement should be:
A. 15 microns
B. 25 microns
C. 50 microns
D. 100 microns

# Increased amount of powder in zinc phosphate cement mixture will cause:
A. Decreased strength
B. Decreased film thickness
C. Decreased solubility
D. Increased setting time

# Which of the following is common to both zinc eugenol cement and polycarboxylate cement?
A. Polyacrylic acid is liquid
B. Chemical bond to tooth structure
C. Chelation
D. Substitution of eugenol by EBA to increase strength of cement

# The addition of which of the following can accelerate the setting time of zinc oxide cement:
A. Zinc acetate
B. Barium sulphate
C. Zinc sulphate
D. Barium chloride

# Which of the following show chemical bond with enamel:
A. Composites
B. Direct filling resins
C. Polycarboxylate cements
D. BIS-GMA resins in pit and fissure sealants

# Which of the following cements is pulpal tissues?
A. Zinc phosphate
B. Silicate
C. Glass ionomer
D. Polycarboxylate

# Which of the following do polycarboxylate and GIC have in common?
A. Polysiloxane
B. Phosphoric acid
C. Polyacrylic acid
D. Ion leachable glass

# pH of polycarboxylate liquid is:
A. 5
B. 7
C. 8
D. 1.7

# Which is the cement with adhesive properties?
A. Zinc oxide eugenol
B. Zinc polycarboxylate
C. Silicate
D. Zinc phosphate

# Eugenol may be replaced in the zinc oxide eugenol cement by:
A. Acetic acid
B. Alginic acid
C. Phosphoric acid
D. Ortho-ethoxy acid

# The setting time of zinc phosphate may be retarded by:
A. Increase in the ratio of powder to liquid
B. Diluting the liquid with water
C. Increase the addition of powder to liquid
D. Decrease the addition of powder to liquid

# Thermal conductivity of which material is close to dentin:
A. Amalgam
B. Silicate
C. Composite resin
D. Cavity varnish

# The logical explanation for the unique anticariogenic property of most silicate cements is:
A. The reduction in enamel solubility due to fluoride uptake by enamel
B. That beryllium flux is used in silicates
C. That silicates show very little leakage at the margins of the restoration
D. Due to the high silica content

# Pulpal medication and thermal protection is given by:
A. Solution liners (2-5μm)
B. Suspension liners (25-30μm)
C. Traditional Liner (0.2-0.3 mm)
D. Cement bases

# Glass ionomer cement is composed of:
A. Zinc oxide powder and polycarboxylic liquid
B. Zinc oxide powder and phosphoric acid
C. Aluminia silicate powder and polcarboxylic liquid
D. Aluminia silicate powder and phosphoric acid

# Which of the following cements is most biocompatible with pulp?
B. Copper cement
C. Zinc phosphate cement
D. Zinc oxide eugenol cement

# The major component of zinc phosphate cement is:
A. Zinc oxide
B. Phosphoric acid
C. Zinc
D. None of the above

# Which of the following cements is most kind to pulp?
A. Glass ionomer
B. Polycarboxylate
C. Silicate
D. Resin cement

# Polycarboxylate cement is used for:
A. Temporary restoration
B. Luting
C. Permanent restoration
D. Die material

# Silicate cement is indicated in:
A. Mouth breathers
B. Patients with high caries index
C. In the restoration of posterior tooth
D. None of the above

# Stages of setting of GIC are:
A. Decomposition, migration, post set hardening, maturation.
B. Migration, decomposition, maturation, post set hardening
C. Decomposition, post set hardening, migration, maturation
D. Decomposition, post set hardening, migration, maturation

# The cement, which is least soluble in oral cavity:
A. Glass ionomer
B. Resin cement
C. Polycarboxylate cement
D. Silico - phosphate cement

# Which of the following restorative material is recommended for root surface caries?
B. Composites
C. Direct filling gold
D. Amalgam

# If hypersensitivity develops in a glass ionomer filled tooth, indicated treatment:
A. Extraction
B. Remove the restoration and place a sedative dressing
C. Remove the restoration perform pulpectomy
D. No treatment is necessary

# The role of itaconic acid copolymer in glass ionomer cement:
A. Reduces the viscosity of the liquid and inhibits gelation
B. Increases the viscosity of the liquid and accelerates gelation
C. Increases cohesion
D. To provide radiolucency

# The advantage of glass ionomer cement reinforced with metal particles is:
A. Decreased strength but biocompatibility
B. Increased resistance to abrasion
C. Better colour
D. Ease of manipulation

# Which is the material of choice to be given in class V cavities?
A. Silicate cement
B. Polycarboxylate cement
C. Glass ionomer cement
D. Unfilled resin

# Initial best sealing of margins is done best by:
B. Acid etched composite
C. Amalgam
D. Polycarboxylate

# Sandwich technique consists of:
A. GIC and composite
B. Amalgam and GIC
C. Amalgam and composite
D. None of the above

# Resin modified glass ionomer is designed to:
A. Provide rapid setting to minimize cement acidity allowing early finishing
B. Reduce the rate of fluoride release
C. Reduce the cost of the product
D. Change the translucency of the products

# After 24 hrs. of setting tensile stength of GIC is:
A. Equal to ZnPO4
B. Greater to ZnPO4
C. Lesser to ZnPO4
D. None of the above

# Bond found in GIC is:
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Metallic bond

# Calcium Hydroxide is used in deep cavities in order to:
A. Form dentin bridge
B. To kill microorganism
C. To cause necrosis
D. As a base under restoration

# Deep caries ( less than 2 mm of dentine remaining) management with resin composite restoration would include:
A. Calcium hydroxide
B. Glass-ionomer cement
C. Dentine bonding agent
D. All of the above

# Vitremer is:
A. Resin modified GIC
B. Metal modified GIC
C. Organically modified composite
D. Polyacid modified composite

# High Viscosity GIC was discovered in:
A. 1970
B. 1980
C. 1990
D. 2000

# Atraumatic Restorative Treatment (ART) technique utilises:
A. Glass ionomer cement
B. Composite resin
C. Silver amalgam
D. Reinforced zinc oxide eugenol cement


# In class II cavity for inlay, the cavosurface margin of the gingival seat clears the adjacent tooth by:
A. 0.20 ± 0.05mm
B. 0.50 ± 0.20mm
C. 0.80 ± 0.35mm
D. 1.10 ± 0.45mm

# Cavities beginning in the proximal surfaces of bicuspids and molars are:
A. Class 1
B. Class 2
C. Class 4
D. Class 6

# Incipient caries consists of opaque, chalky white areas that appear when the tooth surface is dried, this is referred as:
A. white spot
B. hot spot
C. translucent zone
D. body of lesion

# Pit and fissure caries is seen in:
A. Class I
B. Class I compound
C. Class II
D. Class II compound

# Smear Layer consists of:
A. Enamel debris
B. Micro organisms
C. Dentinal chips
D. all of the above

# A butt joint is a:
A. 90° joint
B. 120° joint
C. 70° joint
D. 180° joint

# Enameloplasty is:
A. Filling of enamel fissures with amalgam
B. Elimination of shallow enamel fissures
C. Is same as prophylactic odontomy
D. All of the above

# A prepared cavity is best protected from moisture by:
A. Cotton rolls
B. Saliva ejector
C. Rubber dam
D. Paper napkin

# Retentive grooves in the proximal box of a class II amalgam cavity should be:
A. Sharp and elongated at the dentinoenamel junction
B. Round and elongated in the dentin
C. Round and short in the dentin
D. Sharp and elongated in the dentin

# The term ' Primary Prevention' means all of the following except:
A. Planning the patient's diet
B. Prophylactic odontomy
C. Topical application of fluoride
D. Extending cavity preparation to prevent Recurrence

# Infected dentine shows:
A. Both organic and inorganic components in reversible form
B. Both organic and inorganic components in irreversible form
C. Organic components in irreversible form and inorganic components in reversible form
D. Inorganic component in reversible form and organic component in irreversible form

# Deepening the pulpal floor during cavity preparation provides for:
A. Outline form
B. Retention form
C. Convenience form
D. Resistance form

# In which type of lesion 'eburnation' of the dentine is seen?
A. Acute caries
B. Chronic caries
C. Arrested caries
D. Root Caries

# In case of a deep carious lesion incomplete debridement is done to:
A. Allow secondary dentin formation first
B. To seal the cavity and create aseptic field
C. Prevent pulp exposure and allow a thin layer of a dentin to remain
D. Avoid microleakage

# Beveling of the pulpoaxial line angle of a class II cavity is done to:
A. Increase the strength of the restoration
B. Improved marginal adaptation
C. To prevent the fracture of enamel
D. To prevent the fracture of amalgam

# Restoration of a cusp using dental amalgam requires that:
A. All enamel be removed to provide bulk
B. Only the enamel be removed to conserve tooth structure
C. At least 2 mm of cusp be removed to provide retention form
D. At least 2mm of cusp be removed to provide resistance form

# What is common in class I cavity preparation for amalgam and gold inlay?
A. Buccolingually divergent walls
B. Mesiodistally divergent walls
C. Maximum depth is needed in both cases to provide sufficient thickness
D. All of the above

# In class 2 inlay preparation, How should the pulpal floor be placed in comparison with pulpal floor in amalgam class 2 preparation?
A. Deeper
B. Pulpal floor for amalgam should be placed deeper in dentin
C. Same as Amalgam
D. None of the above

# Class IV cavity:
A. Occurs on the proximal surface not involving the incisal edge of anterior teeth
B. Occurs on proximal surface involving the incisal edge of anterior teeth
C. Occurs on proximal surface involving the incisal edge of posterior teeth
D. Involves the buccal surface of Anterior and posterior teeth

# The retention for class 5 restoration are placed:
A. In mesial and distal areas
B. Occlusal and gingival area
C. In all except the axial wall
D. At expense of axial wall

# Extension for prevention is directly related to:
A. Removal of unsupported enamel on proximal surface of Class III cavity
B. Depth of the axial wall of a class III cavity preparation
C. Elimination of all carious dentin beyond average depth of pulpal wall
D. The outline form of the cavity preparation

# While preparing a Class II cavity on a maxillary first molar which of the pulp horns are likely to get exposed:
A. Mesiolingual and mesiobuccal
B. Distolingual and distobuccal
C. Mesiolingual and distobuccal
D. Distolingual and mesiobuccal

# In a class 1 cavity prepared for silver amalgam is extended to half the distance between the contact area and the fissures and the cusp tip, the direction of the buccal and lingual walls is:
A. Diverging
B. Converging
C. Parallel
D. Independent

# The reason for sealing caries during cavity preparation is:
A. To eliminate the need for eventual direct pulp capping
B. Produce an aseptic filed when pulp exposure is inevitable
C. To allow the formation of secondary dentin before excavation
D. To produce a hard surface as a foundation for subsequent restoration

# In a cavity preparation in which the remaining thickness of dentin is more than 1.5mm, the ideal base is:
A. Ca(OH)2
B. Zinc Phosphate
C. Silicophosphate
D. Glass ionomer

# The function of proximal grooves in a class II cavity is:
A. Resistance form
B. Retention form
C. Increases strength
D. Resistance and retention form

# An incipient carious lesion on an inter proximal surface is usually located:
A. At the contact area
B. Facial to contact area
C. Gingival to contact area
D. Lingual to contact area

# In an ideal restoration, gingival margin should be:
A. Below contact point but 1mm occlusal to gingival crest
B. Below contact point but at level of gingival crest
C. Below gingival crest
D. At contact point

# Gingival extension for a restoration should be:
A. At the gingival crest
B. At least 1mm above the alveolar crest
C. At least 3mm above the alveolar crest
D. Doesn't have any relation with alveolar crest height

# Resistance form of cavity preparation is:
A. Flat pulp floor
B. enough depth of the cavity
C. Restricted size of the external walls
D. all of the above

# During M.O.D. preparation one of the cusps is undermined, indicated treatment is:
A. Reduction of cusp and include in the preparation for on lay
B. Reduction of all the cusps and crown is indicated
C. Strengthened by use of Amalgam core
D. Cusp is beveled and the patient is advised not to exert force on the cusp

# Resistance form is that shape of cavity which:
A. Prevents displacement of restoration
B. permits the restoration to withstand occlusal forces
C. Allows adequate instrumentation
D. Allows the restoration to withstand occlusal forces and prevent displacement

# A dental floss is applied to the distal bow of a clamp, its function is:
A. To facilitate the removal of the clamp
B. To prevent aspiration of clamp
C. To anchor the dam as cervically as possible
D. To stabilize the damp

# Which of the following is commonly recommended procedure for debridement?
A. Citric acid
B. Hydrogen peroxide - 10%
C. Air and water spray
D. Hydrochloric acid

# The axiopulpal depth of the proximal box in class II cavity is:
A. 0.2 to 0.8 mm
B. 0.5 to 1 mm
C. 1 to 2 mm
D. 2 to 3 mm

# Purpose of cavity preparation is:
A. To receive restorating material
B. To cleanse the caries
C. To remove bacteria
D. None

# First step in removing a rubber dam is to:
A. Remove the clamp
B. Release the holder
C. Apply a water soluble Lubricant
D. Cut the interseptal rubber with scissors

# To avoid pulpal irritation below a resistant metallic restoration, the minimum dentin thickness which should remain is:
A. 0.5 mm
B. 1.5 mm
C. 1.0 mm
D. 2.0 mm

# According to Black's classification caries on lingual pits of maxillary central incisors are:
A. Class I
B. Class II
C. Class III
D. Class IV

# In a class II cavity in an incisor the retentive points are placed:
A. At the DEJ
B. In the dentin
C. In the axial wall
D. Never on labial or Lingual walls

# Inappropriate margins in restorations are corrected primarily because:
A. They retain food debris
B. Inhibit proper plaque removal
C. Disturb occlusion
D. Create Sensitivity

# The most common cause of fracture at the isthmus of class II dental amalgam restoration is:
A. Delayed expansion
B. Inadequate depth at the isthmus area
C. Inadequate width at the isthmus area
D. Moisture contamination of the amalgam during placement.

# 'Saucering" out of small pits to improve self cleansing property is called:
A. Saucerisation
B. Enameloplasty
C. Odontotomy
D. None of the above

# Mesial and distal wall of class V cavity depends on:
A. Direction of enamel rods
B. Presence of carious Lesion
C. Contour of gingiva
D. Location of contact area

# The base of class III preparation is:
A. Axial wall
B. Gingival wall
C. Facial wall
D. Lingual wall

# While preparing occlusal cavity for amalgam in mandibular first premolar, the bur:
A. Is kept absolutely vertical
B. Is tilted slightly buccally
C. Is tilted slightly lingually
D. Can be kept in any direction

# Which of the following is not a consideration for obtaining a resistance form during cavity preparation?
A. Stress patterns of teeth
B. Direction of enamel rods
C. Designing outline form with minimal extension
D. Dovetail preparation of restoration to occlusal loading

# Gingivally the depth of a class V cavity is:
A. 0.5 - 1 mm
B. 0.75 - 1 mm
C. 1-1.25 mm
D. 2-3 mm

# For cast restorations the cavity wall should have a taper of:
A. 30-45
B. 5-10
C. 2-5
D. none of the above

# In modified class III cavity restoration retention is obtained mainly by:
A. Acid etching
B. Retentive groove/slot
C. Retentive point
D. Retentive pin

# During cavity preparation, more incidence of exposure is in:
A. Class V cavity in first premolar
B. Class II mesio occlusal cavity
C. Class II disto occlusal cavity
D. Class IV cavity

# Transverse section of Class V through the axial wall is:
A. Convex
B. Concave
C. Kidney shaped
D. Straight

# The cavosurface angle for inlay cavity preparation:
A. 90 degree
B. 150 degree
C. Less than 90 degree
D. 180 degree

# Caries detection dye can stain the following except:
A. Granular necrotic tissue
B. Dry, leathery dentin
C. Reversibly denatured collagen
D. lrreversibly denatured collagen

# The modified class III preparation uses a dovetail on the lingual side in:
A. Maxillary canine
B. Mandibular canine
C. Mandibular central incisor
D. Mandibular lateral incisor

# Preparation of class I cavities for dental amalgam, direct filling gold or gold in lays have in common:
A. Occlusally diverging facial and lingual walls
B. Occlusally diverging mesial and distal
C. Occlusally converging facial and lingual walls
D. Occlusally converging mesial and distal walls

# Which of the following prevents fracture of MO amalgam:
A. Beveling of axiopulpal line angle
B. Occlusal dovetails
C. Pin retained amalgam
D. Removal of unsupported enamel rods

# The non-active carious lesion is distinguished by all except:
A. Covered by a layer of plaque
B. Soft and leathery in consistency
C. Brown or black discolouration
D. Severe pain during caries removal

# In a class III cavity in an incisor tooth the retentive points are placed:
A. At the expense of facial and lingual walls and not in dentin
B. Entirely in dentin
C. In axial wall
D. By placing a groove in the lingual surfaces

# All enamel walls of a cavity preparation must consist of full length enamel rods on
A. Affected enamel
B. Affected dentin
C. Sound enamel
D. Sound dentin

# In air-abrasive technology the abrasive particles used are:
A. Iron oxide
B. Tin oxide
C. Aluminium oxide
D. Silicon oxide

# In an early carious lesion, the first structure to show evidence of destruction is the:
A. Enamel prism
B. Cuticle
C. Interprismatic substance
D. Lamellae

# Which of the following principles of the cavity preparation is not considered much in modern methods of restorative Dentistry?
A. Extension for prevention
B. Convenient form
C. removal of the undermined enamel
D. Removal of the carious dentine

# The wall absent in class V lesion:
A. Axial wall
B. Mesial
C. Distal
D. Pulpal wall

# It is essential to lubricate dam before applying it. Which of these is NOT a suitable lubricant?
A. Shaving cream
B. Liquid soap
C. Scrub gel
D. Vaseline

# Which is the WRONG way to apply dam using a wingless clamp?
A. Put the clamp on the tooth
B. Place the dam on the tooth with fingers, and then position the clamp over it
C. Attach the dam over the clamp and frame outside the mouth, then put the assembly over the tooth using clamp holders OVER THE dam
D. Attach the dam over the clamp and frame outside the mouth, and then put the assembly over the tooth using clamp holders UNDER the dam

# When composites are given, exposed dentin should be covered with:
A. Varnish
B. Calcium hydroxide
C. Phosphoric acid
D. ZnO eugenol cements

# Dental Pulp under any restoration is best protected by:
A. Cavity liner
B. Cavity base
C. 2 mm thick dentin
D. All of the above

# Which one of the following provides most conservative approach while restoring the tooth?
A. Cast gold
B. Dental amalgam
C. Glass ionomer cement
D. Composite resin

# In cavity preparation, line angle is:
A. Union of three surfaces
B. Union of four surfaces
C. The junction of two plane surfaces of different orientation along a line
D. Internal boundary of a cavity

# The tip diameter of a 245 bur used for conventional amalgam preparation is:
A. 2 mm
B. 0.8 mm
C. 0.3 mm
D. 0.4 mm

# The total number of point angles present for Class II amalgam restorations is:
A. 4
B. 6
C. 8
D. 11

# Whenever the caries cone in enamel is larger or at least the same size as that in dentin, it is called as:
A. Residual caries
B. Recurrent caries
C. Forward caries
D. Backward caries

# What is the major difference between a class V cavity preparation for amalgam and one for composite resin by the acid-etch technique?
A. Depth
B. Convenience form
C. Position of retentive points
D. Angulation of enamel cavosurface margins

# Cervical restorations fail mostly due to:
A. Inadequate moisture control
B. Marginal gingivitis
C. Cuspal flexure
D. All of the above

# Proximal walls in a class I tooth preparation for amalgam should:
A. Converge occlusally
B. Diverge occlusally
C. Remain straight
D. Rounded

# The configuration factor ["C" factor] for an occlusal class I cavity is:
A. 2
B. 3
C. 4
D. 5

# Preventive resin restorations are indicated in ?
A. Non-cavitated pit and fissures
B. Deep caries to prevent progress of lesion
C. Cavitated fissures which require restoration
D. Wide cavity to prevent cusp fracture

# In diagnosing the carious lesions, the tooth surface is examined visually and tactilely. Which of the following is NOT considered as visual examination?
A. Cavitations
B. Surface roughness
C. Opacification
D. Softness of the tooth surface

# For gold inlays gingival margin finish line should be:
A. Shoulder preparation
B. Chamfer preparation
C. Bevel
D. Knife edge

# The base of class III preparation is:
A. Axial wall
B. Lingual wall
C. Gingival wall
D. Facial wall

The most reliable sign of sexual maturity in girls is:

 # The most reliable sign of sexual maturity in girls is:
A. Change in voice
B. Age at first menstruation
C. Appearance of pubic hairs
D. Breast development

The correct answer is B. Age at first menstruation.

An interesting phenomenon of the last 300 or 400 years, particularly the 20th century, has been a generalized increase in size of most individuals. There has also been a lowering in the age of sexual
maturation, so that children recently have grown faster and matured earlier than they did previously. Since 1900, in the United States the average height has increased 2 to 3 inches, and the average age of girls at first menstruation, the most reliable sign of sexual maturity, has decreased by more than 1 year. This “secular trend” toward more rapid growth and earlier maturation continued in most countries throughout the 20th century (e.g., the mean age in Poland in 1982 to 1984 was 13.2 years, and 12.8 years in 1992 to 1994) but seems to be leveling off in the developed countries at present. That still means that signs of sexual maturation now appear in many otherwise-normal girls much earlier than the previously accepted standard dates, which have not been updated to match the secular change.

Ref: Proffit 6th Edition.

MCQs on Dental Materials - Restorative Resins


# All of the following statements about the differences between self-polymerizing acrylic resins and heat-cured resins are true EXCEPT:
A. The former have a lower molecular weight
B. The former have higher residual monomer content
C. The former are more porous
D. The former have greater transverse strength

# In heat cure denture base acrylic resins the monomer is:
A. Methacrylate
B. Ethylmethacrylate
C. Methyl ethyl methacrylate
D. Polymethylmethacrylate

# If curing occurs at temperature more than 100°C porosity results in which area of denture?
A. Hard thick central area
B. Thin Palatal area
C. Thin area of flanges
D. Porosity is uniformly distributed

# Which of the following is an example of a composite material?
A. A filled resin
B. Colloidal silica
C. Gold alloy
D. Wax

# Use of dimethyl-P-toluidine is indicated for:
A. Thermal polymerization of acrylic
B. Chemical polymerization
C. Retarding the polymerization reaction
D. To inhibit the action of benzoyl peroxide

# Which of the following initiator accelerator system uses light activation composite?
A. Diketone-amine
B. Organic acid-metal oxide
C. Organic acid-peroxide
D. Peroxide-amine

# Acrylic (cold cure)
A. Melts at 100°c
B. Softens at 100°c
C. Still requires heat for polymerization
D. Produces heat during polymerization

# Hydroquinone is added to methyl methacrylate monomer:
A. To prevent polymerization during storage
B. To initiate release of free radicals
C. To enable polymerization reaction at room tern perature
D. All of the above

# Radio opacity to composite resins is rendered by:
A. Silica glass
B. Organic matrix
C. Barium glass and strontium glasses
D. Fluoride particles

# Cross Linking in denture base resin is contributed by:
A. Glycol dimethacrylate
B. Benzoyl peroxide
C. N-Para toluidine
D. Methyl methacrylate

# The most important disadvantage of acrylic denture base is:
A. Porosity
B. Shrinkage
C. Tooth breakage
D. Water absorption

# Porosity present in a acrylic denture is usually the result of:
A. A prolonged curing cycle
B. Lack of sufficient pressure applied to flask
C. Insufficient acrylic resin monomer
D. Prolonged bench cooling after curing

# Which of the following constituents is common in occlusal sealants, bonding agents, composite resins?
B. Polymethyl methacrylate
C. Benzoin methyl ether
D. Silica filter

# Acrylic resins are used for:
A. Anterior restorations
B. Temporary bridges
C. Denture bases
D. All of the above

# Marginal leakage related to temperature change occurs to the greatest extent with:
A. Amalgam alloy
B. Unfilled resin
C. Composite resin
D. Direct filling gold

# To prevent porosity in self cure acrylic resin, curing should be carried in:
A. Cold water
B. Hot water
C. Under tap water
D. Under vacuum pressure

# In self-cure acrylic resin, activator is:
A. Toluidine
B. Quaternary ammonium compound
C. Benzoyl peroxide
D. Tertiary amine

# The main advantage of composites over unfilled direct filling resin is their:
A. Higher solubility in saliva
B. Lower modulus of elasticity
C. Esthetic excellence
D. Lower thermal co-efficient of expansion

# Composite resins in comparison to acrylic have:
A. Low compressive strength
B. High abrasive resistance
C. High water absorption
D. High polymerization shrinkage

# Composite has:
A. Resin
B. Filler
C. Resin and Filler
D. None

# In processing methyl methacrylate, the resin may show porosity if the flask is placed too soon. Porosity most likely occur
A. Throughout the denture
B. Near the borders
C. In the thickest part
D. On the denture surface

# Boiling point of methyl methacrylate:
A. > B.P of water
B. < B.P of water
C. Equal to BP of water
D. Is at normal room temperature

# Polymerisation of heat-cured methyl methacrylate is initiated by:
A. Tertiary amine
B. Benzoyl peroxide free radical
C. Hydroquinone
D. Methyl ether

# Which of the following is present in the powder of the acrylic resin?
A. Methyl methacrylate
B. Benzoyl peroxide
C. Hydroquinone
D. D-methyl paratolouidine

# Subsurface porosity is due to:
A. Thermal changes
B. Thickness of the resin
C. Lack of temperature
D. Packing past the dough stage

# Light cure system, side effect is:
A. Iritis
B. Cataract
C. Conjunctivitis
D. Retinal damage

# If resin is packed in sandy stage what will be seen in the processed denture?
A. Distortion
B. Porosity
C. Inhomogeneous colour
D. Increased strength

# Bonding of composite resins to tooth structure is by:
A. Covalent bond
B. Ionic bond
C. Mechanical
D. Vanderval forces

# Which one of the following is used as filler in composite resins?
A. Quartz
B. Silica
C. Zinc particles
D. Aluminium

# The type of spatula used to mix composite is:
A. Plastic
B. Stainless steel
C. Iron
D. None of the above

# The chemical used to etch enamel is:
A. Zinc oxide
B. Methyl methacrylate
C. Phosphoric acid
D. Eugenol

# Benzoin methyl ether in a polymer indicates that they may be cured in the presence of:
A. UV light
B. Visible light
C. Infrared light
D. Diketone

# Which of the following procedure is indicated to produce cross-linking in the polymerization of linear chains of acrylic:
A. Addition of grain refining agents
B. Addition of difunctional monomers
C. Increasing the amount of heat required for linear polymerization
D. Incorporation oif terminating agents

# Which of the following may result if an excessive amount of monomer is incorporated into an acrylic resin mixture?
A. Excessive expansion
B. Low impact strength
C. Excessive shrinkage
D. Excessive brittleness

# For photo-curing the composite resin, the light source:
A. Should be held at a millimeter distance from the restoration
B. Need no protection while in use
C. Will cure composite upto a depth of 5 millimeter thickness
D. Is fiber optic

# Porosity of denture base is due to:
A. Packing at dough stage
B. Curing at 160°F for 9 hrs
C. Inadequate pressure
D. All of the above

# The function of the coupling agent in a restorative resin is to allow:
A. Adhesion of resin particles
B. Bonding between filler crystals
C. Bonding between filler and resin
D. Bonding between tooth and resin

# The imperfection seen on the lingual flange of a lower denture caused by rapid heating during a curing cycle is called:
A. Localised shrinkage porosity
B. Gas inclusion porosity
C. Micro-porosity
D. Surface porosity

# No trail closure is necessary with which one of the technique during denture fabrication:
A. Compression moulding technique
B. Injection moulding technique
C. Fluid resin technique
D. Light cured technique

# The particle size in microfilled composites is:
A. 0.02 to 0.04 mm
B. 0.5 to 1.0 microns
C. 0.01 to 0.1 microns
D. 0.3 to 0.4 mm

# A material which is a mixture of two different materials and its properties are:
A. Composite
B. Complex material
C. Combined
D. Compound

# Acid-etching is done for:
A. 30 Seconds
B. 60 seconds
C. 90 seconds
D. 120 seconds

# The polymerization of self-curing resin takes place faster in:
A. Cold water
B. Hot water
C. Under pressure
D. In vacuum

# Coefficient of thermal expansion is highest for:
A. Amalgam
B. Silicate cement
C. Gold alloy
D. Acrylic resin

# Which of the following provide opacity to composite?
C. Ti02
D. None

# The latest method of curing denture base resins:
A. Heat
B. Visible light
C. Chemicals
D. Lasers

# Dentin bonding agents usually contain:
A. Only Hydrophobic component
B. Only Hydrophilic component
C. Hydrophobic and hydrophilic component
D. Lyophillic and lyophobic component

# One of the claims for the superiority composite resin restoration over silicate cement restorations is that the resin restorations:
A. Prevent galvanic action
B. Are practically insoluble in oral fluids
C. Adapt to the walls of the cavity better
D. Have a higher coefficient of thermal expansion

# The advantage of unfilled methyl methacrylate is that:
A. It can be finished smoothly
B. It has a low degree of flow
C. It is non-irritating to pulp
D. Its wear resistant is high

# To cure a heat cure resin, a proper heating cycle is necessary:
A. To prevent the porosity
B. To prevent warpage
C. To prevent volume expansion
D. All of the above

# About polymerization shrinkage of composite all are true, except:
A. Polymerization shrinkage is greater if bonded surface area is lesser than unbounded surface area
B. Polymerization shrinkage is high if within the enamel margins
C. Acid etching and priming will decrease polymerization shrinkage
D. Microleakage can occur because of polymerization shrinkage

# When restoring a tooth with resin material, acid etching can do all of the following except:
A. Increase the surface area
B. Permit chemical bonding between resin and enamel
C. Create surface irregularities in enamel for better mechanical retention of resin
D. Condition the tooth surface for better wetting

# Inorganic phase of the composites aid in:
A. Increasing the mechanical strength
B. Decreasing the coefficient of thermal expansion
C. Reducing the polymerization shrinkage
D. All of the above

# For esthetic areas where high luster is required the restoration that is used usually:
A. Glass ionomer restoratives
B. Hybrid resin composites
C. Microfilled resin composites
D. Macrofilled resin composites

# Inadequate pressure application during flasking:
A. Increases vertical dimension
B. Causes teeth to be shrunken in investment
C. Causes poor quality of colour
D. Causes fracture of denture

# Which of the following absorbs maximum amount of water?
A. Microfilled resin
B. Macrofilled resin
C. Hybrid
D. Small particle composites

# The percentage of free monomer in a heat - cured acrylic resin is:
A. 3% to 5%
B. 8% to 10%
C. 0.2% to 0.5%
D. 0.6% to 0.8%

# The restoration which shows percolation and shrinkage along the margin is:
A. Composites
B. Unfilled resins
C. Amalgam
D. Polycarboxylate

# What is the disadvantage of using composites as restorative material?
A. Increased thermal conductivity
B. Decreased wear resistance
C. Decreased thermal conductivity
D. none of the above

# The commonly used laser for curing composite resin is:
B. CO2
D. Argon

# Insufficient closure of the flasks during packing of denture base resin can result in:
A. Poor colour stability
B. Less polymerization shrinkage
C. Increase in vertical dimension
D. Decrease in vertical dimension

# What is the polymerization shrinkage if 3:1 powder: liquid ratio is used?
A. 6%
B. 8%
C. 10%
D. 21%

# Acrylic resins were first introduced as a denture base material in:
A. 1925
B. 1937
C. 1951
D. 1956

# Macromolecules in Dental Resin is attached by:
A. Covalent bonds
B. Sonic bonds
C. Vander Wall's Forces
D. Hydrogen Bonds

# Quartz tungsten light cure device, minimum output of energy should not be less than:
A. 300 mw/cm2
B. 350 mw/cm2
C. 400 mw/cm2
D. 450 mw/cm2

# Along with polymerisation shrinkage, one of the major disadvantages of polymethyl methacrylate as denture base resin are its poor:
A. Biological properties
B. Thermal properties
C. Mechanical properties D. Esthetic properties

# Denture acrylics contain cross-linking agents, mainly to improve their:
A. Internal color
B. Tissue compatibility
C. Surface hardness
D. Craze resistance

# The most common coupling agents are organic silicon compounds called:
A. parabane
B. ligane
C. silane
D. chelane

# The process wherein two or more chemically different monomers, each with some desirable property, can be combined to yield specific physical properties of a polymer is known as:
A. Step-growth polymerization
B. Addition polymerization
C. Condensation polymerization
D. Copolymerization

# One bottle system of adhesive resins:
A. 4th generation bonding agents
B. Separate etching step not required
C. Separate etching step is still required
D. Contains only primer

# Dentin conditioner has the following function:
A. Removes smear layer
B. Increases surface energy of dentin
C. Forms a thin resin Layer over exposed collagen fibrils
D. Helps in bonding with composite

# Most advantageous indication of acid etching is:
A. Decrease micro Leakage
B. Decrease polymerization shrinkage
C. Decrease coefficient of thermal expansion
D. Decrease porosity in resto rative material

# Residual monomer content of chemically activated resins is:
A. 0.2% to 0.5%
B. 2% to 5%
C. 0.3% to 0.5%
D. 3% to 5%

# VLC resins are also called as:
A. Microwave-activated resins
B. Tertiary amine-activated resins
C. Light activated resins
D. Heat activated resins

# The accepted polymer to monomer ratio for packing of polymethyl methacrylate resin is:
A. 3:1
B. 4:1
C. 10:1
D. 5:1

# Cold cure acrylic expand in water by:
A. 1% by volume 0.23% by weight
B. 10% by volume 0.23% by weight
C. 0.1% by volume 0.23% by weight
D. None of the above

# Etching depth after 30 sec for orthodontic bracket with orthophosphoric acid is:
A. 10 um - 20 um
B. 3 um - 9 um
C. 50 um - 110 um
D. 200 um - 250 um

# Which of the following is NOT true of polymethyl methacrylate?
A. Knoop hardness number 18 to 20
B. Tensile strength of 60 MPa
C. Density of 1.13 g/cm3
D. Modulus of elasticity of 3.4 GPa

# During polymerisation of acrylic resin, above what temperature benzoyl peroxide form free radicals:
A. 25° C
B. 37° C
C. 50° C
D. 60° C

# Etchant preferred in gel form than in liquid form:
A. Better control over placement
B. Enhance and concentrate the action of acid
C. Helps in visualization while placement
D. None of the above

# An acidic agent that dissolves the in organic structure in dentin that allows infiltration of adhesive resin is:
A. Dentin bonding agent
B. Dentin conditioner
C. Primer
D. None of the above

# In acrylic restorative materials, the pumping action of alternately imbibing and excluding fluids is termed as:
A. lmbibition
B. Percolation
C. Syneresis
D. Evaporation

# What is the wave length of visible light used for curing light cure restoration?
A. 400 - 420 nm
B. 250 - 300 nm
C. 420 - 475 nm
D. 300 - 370 nm

# True about conversion of monomer to polymer is:
A. Density changes from 1.19g/cm3 to 0.9 and volume shrinkage is 21%
B. Density changes from 1.19g/cm3 to 0.9 and volume shrinkage is 7%
C. Density changes from 0.9g/cm3 to 1.19 and volume shrinkage is 21%
D. Density changes from 0.9g/cm3 to 1.19 and volume shrinkage is 7%

# According to ADA specification number 12, dough forming time should be less than ______ min. from the start of the mixture.
A. 90 min
B. 60 min
C. 50 min
D. 40 min

# Role of plasticizer in synthetic resins in dentistry is:
A. Increase smoothness
B. To increase bulk
C. To prevent polymerisation shrinkage
D. To reduce softening and fusion temperature

# Of the light produced by quartz - tungsten - halogen, only a small percentage is suitable for curing composite resin material and most is converted into heat. How much percentage of this light is useful for curing?
A. 0.5%
B. 5%
C. 10%
D. 50%