NJXDG LATEST 2026 EXAM QUESTIONS AND SOLUTIONS
RATED A+
✔✔Dental bonding - ✔✔AKA dental adhesion, is the process of attaining a solid and/or
liquid contact of one material with another at a single margin.
✔✔Examples of Enamel bonding - ✔✔The placement of sealants, the bonding or ortho
brackets, and the use of resin-bonded bridges.
✔✔Dentin bonding - ✔✔A major factor in the success of bondings a material to dentin is
the removal of the smear layer, which is a very thin layer (5-10 microns) of debris
composed of fluids and tooth components that remain on the dentin after cavity prep is
completed.
The smear layer protects the tooth by obliterating the openings of the dentinal tubules.
However before dentin bonding is performed the smear layer must be removed through
the process of etching. This allows the dentinal tubules to open up more for the bonding
material to flow in.
✔✔What occurs in a bonding system - ✔✔The tooth is etched and bonded. Once
material is placed it will be allowed to
1) harden and act as a hybrid layer OR
2) remain in liquid state while the restoration is being placed, to bond together the tooth
and the dental material.
✔✔Guidelines for clinical application of bonding products - ✔✔- perform the steps in the
bonding process precisely
- avoid expiration, contamination, and thickening of liquids
- remove any plaque or debris before beginning the bonding process
- avoid overdrying the dentin; these products work best on a slightly moist tooth
structure
- Note that too much bonding material is better than too little; multiple layers work best
- Ensure that the bonding solution covers all surfaces
- Avoid any contamination w saliva, blood, or debris, which will require the entire
procedure to be redone
- allow as much time as possible for the bond to mature before completing the
restoration and removing the cotton rolls or dental dam.
✔✔Initial cavity preparation - ✔✔First involves the initial design and extension of the
preparation's external walls to a limited depth.
Outline form
- The dentist decides on the design and initial depth of sound tooth structures.
Resistance form
,- The dentist determines the primary shape and placement of the cavity walls.
Retention form
- The dentist knows where to place retention in the prep to help in securing the
restoration in place.
Convenience form
- The dentist has accessibility in preparing and restoring the tooth.
✔✔Tooth preparation walls terminology - ✔✔Cavity wall
- internal surface of the tooth prepared for the restoration
Internal wall
- cavity wall/surface that does not extend to the external tooth surface
External wall
- surface of the tooth prep that extends to the external tooth surface; named according
to the tooth surface involved: mesial, facial, lingual, or gingival
Axial wall
- internal wall/surface of the prepared tooth that runs parallel to the long axis of the tooth
Pulpal wall
- internal wall/surface of a prepared tooth that is perpendicular to the long axis of the
tooth; aka the pulpal floor
Enamel wall
- portion of a prepared external wall that consists of enamel
Dentinal wall
- portion of a prepared external wall that consists of dentin
✔✔Tooth preparation angles terminology - ✔✔Line angle
- Angle formed by the junction of two walls/surfaces in a cavity preparation (similar to
angle formed when two walls of a room meet to form a corner). To identify a line angle,
the names of the 2 involves walls/surfaces are combined. For example, the angle
formed by the mesial and lingual walls is called the mesiolingual line angle. It is
important not to confuse the names of these angles with the names used to describe
the surfaces involved in the restoration itself.
Point angle
- Junction of three walls/surfaces that are coming from a different orientation.
✔✔Final cavity preparation - ✔✔- Removing any remaining enamel within the prep,
diseased dentin, or old restorative material (or a combination).
, - Inserting additional resistance and retention notches, grooves, and coves to provide
strength in maintenance of the restoration.
- Placing dental materials, which can include lining agents, bases, and desensitizing for
protective purpose, or bonding agents, for pulpal protection and better retention.
✔✔Class I restorations - ✔✔One surface lesion that involves the pits and fissures of a
tooth.
Articulating paper must be used to check bite. The Dentist will use a bur to open
enamel, taking care not to create any sharp angles or corners within prep. Prep should
be smooth throughout internal structure.
- occlusal pits and fissures of premolars and molars
- buccal pits and fissures of mandibular molars
- lingual pits and fissures of maxillary molars
- lingual pits of maxillary incisors
✔✔Class II restorations - ✔✔Extension of class I into the proximal surfaces of the
premolars and molars.
A matrix system is required for this procedure. Because proximal surfaces are hard to
reach, the dentist will include the occlusal surface in prep and restoration of tooth. If
decay extends into dentin, additional retention in cavity prep will be required, with the
use of rotary instrument and bonding material.
Conservative: involving two surfaces.
Comprehensive: involving 4+ surfaces and removal of a cusp.
✔✔Class III and IV restorations - ✔✔Class III affects the interproximal surfaces of
incisors and canines.
Composite will be used for aesthetic purposes with special attention to shade selection.
Use a Mylar matrix system and a dental dam is advised. If possible dentist will enter
tooth from lingual side to reduce size of restoration on facial side.
Class IV involves the interproximal surfaces of incisors and canines and also the incisal
edge.
✔✔Class V restorations - ✔✔A smooth surface restoration that occurs on the gingival
third of the facial or lingual surface of any tooth.
Prepared by having a smooth line with no angles. Dentist may use dental dam or
retraction cord to retract the gingiva away from the tooth.
✔✔Complex restorations - ✔✔When the loss of tooth structure becomes greater than
what is remaining of tooth, the dentist will decide whether to
RATED A+
✔✔Dental bonding - ✔✔AKA dental adhesion, is the process of attaining a solid and/or
liquid contact of one material with another at a single margin.
✔✔Examples of Enamel bonding - ✔✔The placement of sealants, the bonding or ortho
brackets, and the use of resin-bonded bridges.
✔✔Dentin bonding - ✔✔A major factor in the success of bondings a material to dentin is
the removal of the smear layer, which is a very thin layer (5-10 microns) of debris
composed of fluids and tooth components that remain on the dentin after cavity prep is
completed.
The smear layer protects the tooth by obliterating the openings of the dentinal tubules.
However before dentin bonding is performed the smear layer must be removed through
the process of etching. This allows the dentinal tubules to open up more for the bonding
material to flow in.
✔✔What occurs in a bonding system - ✔✔The tooth is etched and bonded. Once
material is placed it will be allowed to
1) harden and act as a hybrid layer OR
2) remain in liquid state while the restoration is being placed, to bond together the tooth
and the dental material.
✔✔Guidelines for clinical application of bonding products - ✔✔- perform the steps in the
bonding process precisely
- avoid expiration, contamination, and thickening of liquids
- remove any plaque or debris before beginning the bonding process
- avoid overdrying the dentin; these products work best on a slightly moist tooth
structure
- Note that too much bonding material is better than too little; multiple layers work best
- Ensure that the bonding solution covers all surfaces
- Avoid any contamination w saliva, blood, or debris, which will require the entire
procedure to be redone
- allow as much time as possible for the bond to mature before completing the
restoration and removing the cotton rolls or dental dam.
✔✔Initial cavity preparation - ✔✔First involves the initial design and extension of the
preparation's external walls to a limited depth.
Outline form
- The dentist decides on the design and initial depth of sound tooth structures.
Resistance form
,- The dentist determines the primary shape and placement of the cavity walls.
Retention form
- The dentist knows where to place retention in the prep to help in securing the
restoration in place.
Convenience form
- The dentist has accessibility in preparing and restoring the tooth.
✔✔Tooth preparation walls terminology - ✔✔Cavity wall
- internal surface of the tooth prepared for the restoration
Internal wall
- cavity wall/surface that does not extend to the external tooth surface
External wall
- surface of the tooth prep that extends to the external tooth surface; named according
to the tooth surface involved: mesial, facial, lingual, or gingival
Axial wall
- internal wall/surface of the prepared tooth that runs parallel to the long axis of the tooth
Pulpal wall
- internal wall/surface of a prepared tooth that is perpendicular to the long axis of the
tooth; aka the pulpal floor
Enamel wall
- portion of a prepared external wall that consists of enamel
Dentinal wall
- portion of a prepared external wall that consists of dentin
✔✔Tooth preparation angles terminology - ✔✔Line angle
- Angle formed by the junction of two walls/surfaces in a cavity preparation (similar to
angle formed when two walls of a room meet to form a corner). To identify a line angle,
the names of the 2 involves walls/surfaces are combined. For example, the angle
formed by the mesial and lingual walls is called the mesiolingual line angle. It is
important not to confuse the names of these angles with the names used to describe
the surfaces involved in the restoration itself.
Point angle
- Junction of three walls/surfaces that are coming from a different orientation.
✔✔Final cavity preparation - ✔✔- Removing any remaining enamel within the prep,
diseased dentin, or old restorative material (or a combination).
, - Inserting additional resistance and retention notches, grooves, and coves to provide
strength in maintenance of the restoration.
- Placing dental materials, which can include lining agents, bases, and desensitizing for
protective purpose, or bonding agents, for pulpal protection and better retention.
✔✔Class I restorations - ✔✔One surface lesion that involves the pits and fissures of a
tooth.
Articulating paper must be used to check bite. The Dentist will use a bur to open
enamel, taking care not to create any sharp angles or corners within prep. Prep should
be smooth throughout internal structure.
- occlusal pits and fissures of premolars and molars
- buccal pits and fissures of mandibular molars
- lingual pits and fissures of maxillary molars
- lingual pits of maxillary incisors
✔✔Class II restorations - ✔✔Extension of class I into the proximal surfaces of the
premolars and molars.
A matrix system is required for this procedure. Because proximal surfaces are hard to
reach, the dentist will include the occlusal surface in prep and restoration of tooth. If
decay extends into dentin, additional retention in cavity prep will be required, with the
use of rotary instrument and bonding material.
Conservative: involving two surfaces.
Comprehensive: involving 4+ surfaces and removal of a cusp.
✔✔Class III and IV restorations - ✔✔Class III affects the interproximal surfaces of
incisors and canines.
Composite will be used for aesthetic purposes with special attention to shade selection.
Use a Mylar matrix system and a dental dam is advised. If possible dentist will enter
tooth from lingual side to reduce size of restoration on facial side.
Class IV involves the interproximal surfaces of incisors and canines and also the incisal
edge.
✔✔Class V restorations - ✔✔A smooth surface restoration that occurs on the gingival
third of the facial or lingual surface of any tooth.
Prepared by having a smooth line with no angles. Dentist may use dental dam or
retraction cord to retract the gingiva away from the tooth.
✔✔Complex restorations - ✔✔When the loss of tooth structure becomes greater than
what is remaining of tooth, the dentist will decide whether to
