Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Fixed prosthodontic treatment can offer exceptional satisfaction for both patient and the dentist. Fixed Prosthodontics can transform an unhealthy, unattractive dentition with poor function into a comfortable, healthy occlusion capable of giving years of further service while greatly enhancing esthetics.
Nothing is more important in the construction of fixed partial dentures than an adequate diagnosis and a well-devised treatment plan. Although these two subjects are usually considered together. Astute dentists must recognize their subtle differences. Diagnosis is an evaluation of the condition of the patient when he presents for treatment. Treatment planning concerns the treatment procedures by which the dentist will restore the patient to an optimum state of dental health.
The cast metal restoration is versatile and is especially applicable to Class II onlay preparations. The process has many steps, involves many dental materials, and requires meticulous attention to prepration.
Tooth treatment planned to be restored with an intracoronal restoration, but the decay or fracture is so extensive that a direct restoration, such as amalgam or composite, would not be able to sustain or bear forces.
Additionally, when decay or fracture incorporate areas of cusp or remaining tooth structure that undermines perimeter walls of a tooth, an onlay might be indicated.
Fixed prosthodontic treatment can offer exceptional satisfaction for both patient and the dentist. Fixed Prosthodontics can transform an unhealthy, unattractive dentition with poor function into a comfortable, healthy occlusion capable of giving years of further service while greatly enhancing esthetics.
Nothing is more important in the construction of fixed partial dentures than an adequate diagnosis and a well-devised treatment plan. Although these two subjects are usually considered together. Astute dentists must recognize their subtle differences. Diagnosis is an evaluation of the condition of the patient when he presents for treatment. Treatment planning concerns the treatment procedures by which the dentist will restore the patient to an optimum state of dental health.
The cast metal restoration is versatile and is especially applicable to Class II onlay preparations. The process has many steps, involves many dental materials, and requires meticulous attention to prepration.
Tooth treatment planned to be restored with an intracoronal restoration, but the decay or fracture is so extensive that a direct restoration, such as amalgam or composite, would not be able to sustain or bear forces.
Additionally, when decay or fracture incorporate areas of cusp or remaining tooth structure that undermines perimeter walls of a tooth, an onlay might be indicated.
This presentation is all about restoration of endodontically treated teeth, prefabricated post and core, cast post and core, direct and indirect technique.
An inlay may cap none, or may cap all but one cusp.
Sturdevant’s 4th ed. page579
Inlays may be used as single-tooth restorations for proximo-occlusal or gingival lesions with minimal to moderate extensions
Shillingburg page 1
An inlay may be defined as a restoration which has been constructed out of mouth from gold, porcelain, or other material & then cemented into the prepared cavity of a tooth.
William McGehee pg410
a detailed account of the principles of tooth preparation with main reference from Shillingburg
The presentation is available on request. Mail me at apurvathampi@gmail.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
This presentation is all about restoration of endodontically treated teeth, prefabricated post and core, cast post and core, direct and indirect technique.
An inlay may cap none, or may cap all but one cusp.
Sturdevant’s 4th ed. page579
Inlays may be used as single-tooth restorations for proximo-occlusal or gingival lesions with minimal to moderate extensions
Shillingburg page 1
An inlay may be defined as a restoration which has been constructed out of mouth from gold, porcelain, or other material & then cemented into the prepared cavity of a tooth.
William McGehee pg410
a detailed account of the principles of tooth preparation with main reference from Shillingburg
The presentation is available on request. Mail me at apurvathampi@gmail.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Inlays and onlays / implant dentistry course/ implant dentistry courseIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
What is a Cavity | Dentist Karen Chu Info Bitekarenchudmd
Children's dentist Karen Chu shares an info bite - basic information parents can share when their kids ask the question, 'What is a cavity' or about tooth decay. - Phoenix Kids Dentist Karen Chu.
Auxillary methods of retention in class ii dental amalgam restorationsIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
silver Amalgam cavity preparation for class 1 /certified fixed orthodontic co...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Cavosurface margins in various restorations /certified fixed orthodontic cou...Indian dental academy
Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Restoration of endodontically treated teeth 1 /certified fixed orthodontic c...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Indian Dental Academy: will be one of the most relevant and exciting
training center with best faculty and flexible training programs
for dental professionals who wish to advance in their dental
practice,Offers certified courses in Dental
implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic
Dentistry, Periodontics and General Dentistry.
Principles of tooth prep /certified fixed orthodontic courses by Indian denta...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Similar to Intra & extra coronal restoration resistance form /certified fixed orthodontic courses by Indian dental academy (20)
Opportunity for Dentists (BDS/MDS )to relocate to United kingdom -Register as a DENTAL HYGIENIST/ DENTAL THERAPIST without Board exams and after approval you can register in GDC as a DH/DT and start working as a DH/DT Immediately and get paid.
You can complete the whole process in 3-4 months.Salary range for DH/DT is around 2500-3500 Pounds per month.
Eligibility / requirements-
1. An International English Language Testing System (IELTS) certificate
at the appropriate level.(Within 2 yrs of application date )
2: A recent primary dental qualification that has been taught and examined in English..(Within 2 yrs of application date )
3: A recent pass in a language test for registration with a regulatory authority in a country where the first language is English.
If you are interested Please contact us for more details.
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...Indian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals
who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry,
Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
I –Aligners are made with FDA approved transparent thermoplastic materials using 3D scanning, 3D Printing and finally Trays with Pressure vacuum formers.
Dear Doctor,
Indian Dental Academy Now offers comprehensive online Orthodontics course.
Course includes:
1.whiteboard lecture presentations
2.Case Discussions
3.with hundreds of pictures.
4.Demo on Models
5.Demo on Patients
6. subtitles in your own language
12 months unlimited access and support @350 USD only.
For Demo please visit :www.idalectures.com/preview/
For more details visit: www.idalectures.com
Please contact us for any clarifications:
idalectures@gmail.com
indiandentalacademy@gmail.com
Thanks & Regards
Indian Dental Academy
--
Indian Dental Academy
Leader in continuing dental education
www.indiandentalacademy.com
skype:indiandentalacademy
+919248678078
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Diagnosis and treatment planning in completely endntulous arches/dental coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Properties of Denture base materials /rotary endodontic coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Use of modified tooth forms in complete denture occlusion / dental implant...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Intra & extra coronal restoration resistance form /certified fixed orthodontic courses by Indian dental academy
1. Resistance form for intracoronal
and extracoronal Dental
restorations
INDIAN DENTAL ACADEMY
Leader in Continuing Dental Education
www.indiandentalacademy.com
www.indiandentalacademy.com
2. • Introduction.
building restoration is similar to building any
mechanical structure, in that the stress pattern
of the available foundation and contemplated
sytucture must be predetermined.
The fundamental concept form of resistance form
is based on reaction with the restoration and
remaining tooth structure to the occlusal loading.
www.indiandentalacademy.com
3. • Def.
Resistance form may be defined as the shape and
placement of preparation wall that best enables
both the restoration and the tooth structure to
withstand, without fracture, masticatory forces
delivered principally in the ong axis of the tooth.
www.indiandentalacademy.com
4. • Sress patterns of teeth.
Anterior teeth.
a.The incisal edges espicially if they are square are
subject to tensile and shear stress in normal
occlusion. Masive stresses are present in edge to
edge occlusion.
b.The slopes of the cuspids will bear concentrated
stresses (three types) espicially if the cuspid is
protector of occlusion.(canine protected occlusion).
c. The distal surface of the cuspid exhibits unique
stress pattern as a result of anterior component of
force concentrating compressive loading at the
junction of anterior and posterior of dental arch and
microlateral movement of cuspidsduring excrusive
www.indiandentalacademy.com
5. Movements. These factors leads to tremendous
stress concentration with resultant abrasive
activity.
D. The lingual concavity in the upper anterior teeth
bears substatntial compressive stress during
centric and shear stress during protrusive
movements.
e. The incisal edges of the lower anterior teeth are
subjected to compressive stress in centric and
shear stresis in protrusive movements.
2. Srress patterns in posterior tooth.
a. Functional cusp tips bears compressive stresses.
b. Marginal and crossing ridges bears tremendous
compressive and shear stresses.
www.indiandentalacademy.com
6. c. During function compressive stress is on the
occluding contacting side and tensionon non
contactiing side. The junction of crown and root bears
tremendous shear stress during lateral excursion.
Some Applied Mechanical Properties Of Teeth.
Compressive strength of enamel supported by vital
Dentin 36-42000 psi.
When enamel looses support of dentin it looses more
than 85% of its strength.
Compressive strength of dentin os 40-50,000 psi
Non-vital dentin looses 40-50% its strength.
www.indiandentalacademy.com
7. • Resistance form is of two types.
• Primary resistance form.
Primary resistance form is established during the
initial tooth preparation stage.
Principles.
1. Use box shape with relatively flat floor.
2. Restrict extension of the external walls to allow
strong cusp and ridge areas with sufficient dentin
support.
3. Slight roundening of the ine angles
4. Cap weak cusps in extensive preparations.
5. To provide enough thickness of restorative
materials to prevent its fracture under load.
www.indiandentalacademy.com
8. • Factors affecting the resistance resistance form.
• A. Remaining tooth structure.
The amount of remaining tooth structure also affect the
need and type of resistance form. Very large tooth
even though extensively involved with caries or
defects require less resistance form consideration,
espicially in regards to cusp capping because th
eremaining tooth structure is still bulky and strong
enough to resist fracture.
b. Type of restorative material.
Amalgam requires minimum of 1.5mm thickness for
sufficient strength, cast metal requires 1mm and
ceramics 2mm. www.indiandentalacademy.com
9. • Amalgam.
• Class I Preparation.
• 1.Should have a Mortoise shape.
• Features.
• Seat of the restoration is at right angle to the
direction of stresses.
• It prevents buccal and lingual splitting
• 2. If caries penetrates deeply removing the
undermining caries would lead to conical
preparation. (fig)
• 3. when th epreparation walls comes in cantact with
marginal ridge , the wall should be divergent pulpo-
occlusally. www.indiandentalacademy.com
10. • 4.when ever preparation wall comes in contact with a
crossing ridge make the wall perpendicular to the
pulpal floor.
• 5. The width of the preparation should be ¼ to 1/5 the
intercuspal distance(Not less than 1.5mm).
distance(Not less than 1.5mm).
• 6.The crossing ridges should be preseved ie. No
effort should be made to them in preparartion unless
dictated by caries. Loss or involvement of such
crossing ridges is often more detrimental to the tooth
than loss or involvement of marginal ridge.
• 7.whenever preparation comes very close to the cuspl
tips thinning them to the extent that they cannot be
self resistance, it is advisable to flatten these
cusps(Cusp www.indiandentalacademy.com
capping) creatng a table with a minimum
11. • 8. when it is required to cross marginal ridge,
faciolly or lingually, the following rules must be
observed
• i.preserve the width being crossed. It should
be 1.5mm or dictated by cariogenic factors.
• ii. If small cusp is being isolated from the rest
of the tooth (weakening it) elevate the pulpal
floor at the crossing isthmus is advisable..
• 9. all cavosurface angles should be right angles
to create butt joint with amalgam.
• 10. all line and point angles should be rounded.
www.indiandentalacademy.com
12. • Class II .
Occlusal loading and its effects.
a. A small cusp contact the fossa away from the
restored proximal surface in a proximoocclusal
restoration I centric closure.(Fig)
www.indiandentalacademy.com
13. • 2. a large cusp contacts the fossa adjecent to the
restored proximal surface in a proximo-occlusal
relation at centric closure.
www.indiandentalacademy.com
14. 3. Occluding cuspal elements contacts facial or lingual
tooth structures surrounding a proximo-Mocclusal
during centric and excursion movements.
www.indiandentalacademy.com
15. 4. Ocludin cuspal elements contacts the facial or
lingual parts of restoration surrouded the tooth
structure during the centric.
www.indiandentalacademy.com
16. 5.Contacts at the facial or lingual parts of restoration
which completely replaces the facial or lingual parts.
www.indiandentalacademy.com
17. • 6. contacts at the marginal ridges.
www.indiandentalacademy.com
18. Design Features for the mechanical integrity of the
restoration.
a. Isthmus.
The junction between the occlusal part of the
restoration and proximal, facial or lingual parts,
potentially deleterious tensile stresses occur.
Studies reveals three things
I. Flucrum of bending ocurs at the axiopulpal line
angle
II. Stresses incresae closer to the restotation away
from fulcrum
III. Tensile stresses predominate at the marginal
ridge area.
www.indiandentalacademy.com
19. Materials tend to fail therefore starting from the
surface near the marginal ridge and proceeding
internally.
These problems can be solved by applying three
engineering principles.
www.indiandentalacademy.com
20. • The advantages of this design are
1. Increases accessibility to th eproximal surface
2. Sharp junctions are avoided ,which would otherwise
concentrate stresses in the restoration.
3. It increases the bulk of the amalgam
Other features for the isthmus are
a.The pulpal and gingival floor should be perfectly flat in
order to resist forces at the most advantageous
angulatrion.
b. Every prt of the preparation (Facial, occlusal, lingual,
proximal) should be self retenrive. If every part of
the restoration is locked independently there will be
minimum stresses at the junction of one part with
anotherie.www.indiandentalacademy.com
Isthmi.
21. Margins.
Four design features.
1.Butt joint
2.Leave no frial enamel at cavosurface margin
3. Remove flashes of amalgam on tooth surface
adjecent to the enamel margins.
4. As practically a s possible the interface between the
amalgam and tooth structure should not be at
occluding contact area.
Cusp and Axial angles.
1. Bulk of amalgam in all three dimensions should be
1.5mm.
2. Each portion should be independently immobilised
with retention modes.
www.indiandentalacademy.com
22. 3. Amalgam should be seated on a flat floor or table in
this area.
Design Features for protection of physiomechanical
integrity of tooth structure.
1..Isthmus.
The width of the preparation should not exceed more
than 1/4 to 1/5 the intercusapl distance. If it is
exceeded, it results in iuncresaed internal stresses
in the tooth, reduces tooth resistance to fracture
2.If the class II preparation includes the occlusal
surface all the basic features in the prepareation
should be included.
3.Cuspa and axial angles.
As in class I preparation the ideal length to width ratio
www.indiandentalacademy.com
23. Should be less than 1:1 (Mesiodistally :buccolingually), if
the ratio is more than 2:1 then this part of the cuspal
wall should be shortened untill there is a maximum
ratio of 1:1 this is done in form of flat table to
accommodate 1.5mm thickness of amalgam.
Facial and lingual retentive grooves should not br deep
as to undermine enamel.
Margins.
Facial and lingual walls of the occlusal surface approach
the proximal surface, they should meet at right angle.
www.indiandentalacademy.com
24. Class III
1. Anterior component of forces concentrates at the
junction between the anterior segment of the arh
and the premolar region.the cuspids stand at this
corner where these forces will first be receieved
and distributed
2. The incisal slopes of cuspids in normal excursion
mechanism will be the last to disocclude during
lateral excursion so the canines carries maximum
occlusal load for the longest time.
3. If the incisal margin is located far enough onto the
distal slope, restoration will be directly loaded
vertically and horizontally a situation that
necessiates maximum strength.
www.indiandentalacademy.com
25. To overcome these forces, the tooth preparation on the
distal of the cuspid should have
1. Bulkiest walls possible
2. Minimal incisal extension.
Tooth coloured materials have no chance of
withstanding these types of forces. If esthetics is of
great concern here due to extensive labial extension,
an amalgam restoration can be built with a windiw
like cavity on the labial side which can be later
restored with tooth colouredmaterial.
www.indiandentalacademy.com
26. • Class V .
• 1. the margins should not be placed on the cementum
as it lacks self resistance.
• 2.in cases the lesion is close to the bifurcation and
trifurcation areas, special attention should be given to
the gingival margins and walls. Gingival floor should
be flat, one planed, and with no retentive grooves ,
this allows more bulk to the tooth structure.
• 3. to protect the critical axial angles of the tooth the
mesial and distal walls should diverge axiofacially or
lingually.
www.indiandentalacademy.com
27. • Pin retained amalgam restorations.
• Mechanical aspects of pin retaine
dfrestorations.
• Stressing capabilities of pins.
• Stresses are always inudced in dentin as a result os
pin insertion.if the stresses exceeds th elastic limit of
the dentin permanent deformation occurs.
• Types of pins.
• 1.Smaller the diameter of the pin compared to pin hole
lesser willl be the stress.
• 2. Diameter of pins.
• Greater the diameter of pin greaterr will be the stress.
www.indiandentalacademy.com
28. 3. pin depth and dentinal engagement.
greater the depth of pin channel greater will
be the stresses
4. Bulk of dentin.
the greater the bulk of dentin pulpally or
towards the surface of pin is, the less will be
the stresses per unit volume.
5. Type of dentin
6. Inter pin distance.
7. Loose pins.
8. Ratio of the depth of the pin into the dentin to
that pritruding into the preparation.(2:1)
www.indiandentalacademy.com
29. • Retentive Features in the remaining portion of the
tooth.
• Pins and restorative material..
• 1. Pin will not increase the compressive strength of
restorative material. They will only help in retaining
it.Infact there will be a drop in compressive strength
and tensile strength.
www.indiandentalacademy.com
30. Cast metal restorations.
cast metal restorations are alternative to amalgam
when higher strength is needed. Their main
advantages are high conpressive and tensile
strengths.
They are basically indicated to support the
weakened tooth like large restorations,
endodontically treated teeth, teeth at risk of
fracture.
www.indiandentalacademy.com
31. • Resistance features.
• Flat pulpal floor
• Incluson of weakened tooth structure
• Preservation of cusps and marginal ridges
• Reduction of cuspa when indicated.
• Minimm thickness of the metal can be 1.mm.
• 30 degree marginal bevel provides burnishable metal
which protects the enamel margins.
• Resistance form can be incresaed by conservig the
tooth structure.
• a. enameloplasty
• b. marginal bevel can be used to include (eliminate)
terminal end of the fissures in outline form.
www.indiandentalacademy.com
32. if majhor facial and lingual extension is required to
remove undermined enamel capping the weakened
cuspal structure is indicated.
www.indiandentalacademy.com
33. • Tooth coloured restorations.
• Ideally restorations made of ooth coloured materials
should not be loaded directly ,ie., there should be
intervening tooth structure between occluding tooth
and restorations.
• Composite resins are only non cast materials that can
combine undermine enamel and cuspal elements to
sound tooth structure there by improving resistance
form.
• Consrevative composite restorations.
this typr of design is used for smallpits and fissures.
It allows for restoration of lesion or defect with minimal
removal; removal of tooth structure. It is termed as
conseravtivewww.indiandentalacademy.com
composite restoration(CCR).
34. Resistance features.
The design is primarily conventional design.
The thickness of th erestorative material should be
minimum1.75mm.
The roundness of the lineangles should be more
exagerrated trhen amalgam because of brittle nature
of materials.
Walls directly loaded i.e., in contact with opposing teeth
in centric and non centric occlosion should be formed
by enamel supported by dentin.
In areas where extensive caries undermines the cusps it
is advisable to skirt these areas. It is applicable for
functional cusps rather than non functional cusps.
Knife edge enamel should be trimmed and flattened.
www.indiandentalacademy.com
35. In high stressed areas in centric an eccentric contacts it
is essential to create sufficient eeduction of tooth
structure for bulk of restoartion.
Of all the surrounding walls in class II, III andiV
preparation, the gingival wall is most important in
shaping the resistance form. It should be as
pronounced as anatomically possible
The margins should not be placed close tro the
important anatomicx struictures like incisal angle,
marginal ridge and axialangle, this will leave the tooth
bulk espicially dentinal support to these structures.
www.indiandentalacademy.com
36. • The modofied preparation for composites conserve
more tooth structure because retention is obtained
primarily by micromechanical adhesion to the
surrounding enamel and underlying dentin, rather than
by preparation of retention grooves or coves in dentin.
www.indiandentalacademy.com
37. • Effect of polymerization shrinkage on resistance form.
Moder n composites undergo polymerisation shrinkage
from 2.6% to 7.1%.
During polymerization resin composite may pull away
from least retentive margin resulting in gap formation.
Tensile forces developed in enamel margin can result in
margination degration mastication.
Contraction forces on cusps can result in cuspal
deformation, enamel cracks and crazes and ultimately
decreased fracture resistance of cusps.
Prevention.
Incremental palcement.
Beta quartz inserts
www.indiandentalacademy.com
Auto cured resin has less polymerisation shrinkage.
38. • Two step or soft start polymerisation.
Initial irradiation150 mW/cm2 followed by high level
irradiation 650 mW/cm2.
www.indiandentalacademy.com
39. Extracoronal resistance form.
Cusp capping.
It is a method of encompassing a cusp with a restorative
material to increase the resistance form of the tooth.
Indications.
If the preparatiion outline extends 2/3 the distance from the
central groove to the cusp tip.
Cusp cappng provides
1. Protection of the weakened tooth structure.
2. Remove occlusal margin from a region subjected to heavy
stress and wear.
Materials used
Amalgam
Cast gold.
www.indiandentalacademy.com
40. • Cuspal reduction for capping for amalgam is doneby
reducing the cusp 2mm and making a flat table.
• For cast metal it is done by placing occlusal bevel ,
the Table and the counter becvel.
www.indiandentalacademy.com
41. • Capping of margianl ridge.
• It is done when the marginal rige is
weakened and the embrasure is pronounced
• It is similar to capping a cusp but on a klesser
scale.
• C apping the ocluso proximo facial or lingual
corners of preparation.
• It is done to protect the thinned corners due
to over preparation or wide preparation in
ovoid tooth.
• Over the facial or lingual extension a bevel
extension is added ending in a knife edge or
chamfer finishing line.
www.indiandentalacademy.com
42. • Peripheral sleeve.
• This feature add resistance for amalgam
preparation design.
• It is 2mm axial and 11mm cervicall deep
prepared feature.
www.indiandentalacademy.com
43. Onlay.
It is partly intracoronal and pertly extracoronal
restoration which has cuspal proection as main
feature.
Mainly indicated for cuspal protection,when the width
of the lesion has exceeded ½ the intercuspal
distance. The cusps are protected by dong cusp
capping on the functional cusp and <Shoeing< on
the non functional cusps.
Resistance features.
Secondary Flare.
www.indiandentalacademy.com
44. It is indicated when the surface extension are
required to include facial lingual defects beyond the
line angles of the tooth.
Surface extension is necessary to encompass an
axial angle for reinforcement and support.
Secondry bevel is is in the form of partial bevel. It
involves enamel only, with its maximum depth at
the main cavity preparation. It ends at the facial and
lingual surface with knife edge finishing line.
www.indiandentalacademy.com
45. • Skirt.
• For cast metal.
• It is more extensive surface extension than
secondary flare. It is imparts retention and retention
to a missing or shortened facial or lingual wall.
• It is used
• Features.
• It includes a part of the facial and lingual surfaces
near the axial angle to a depth of 0.5 to 2mm.it ends
with a chamfer or a hollow ground bevel.
• It should be terminated in the facial or lingual groove.
www.indiandentalacademy.com
46. • For composites.
• In areas where extensive caries undermines the
cusps it is advisable to skirt these areas. It is
applicable for functional cusps rather than non
functional cusps
www.indiandentalacademy.com
47. Collar.
This type of surface extension is most involving surface
wise and depth wise.i could be
a. cuspal collar. (ivolving one cusp )
b. Tooth collat. (Involving the entire facial or
lingual surface)
The help in retention and resistance when the entire cusp is lost.
A collar can accommodate both metal and porcelin b.ulk in PFM
restoration.
Features.
It has axial depth of 1.5 to 2mm.
It ends gingivally in bevelled shoulder finishing line.
There should be a definite line angle at the shoulder and axial
collar. www.indiandentalacademy.com
48. • STEP 3 PRIMARY RETENTION
• Definition:
• Is that shape (or) form of the prepared
cavity that resists displacement (or)
removal of the restoration from tipping (or)
lifting forces.
• According to their locations, retention
means can be classified as
• 1. Intracoronal (With in the tooth)
• 2.Extracoronal (On preparation surface
• replacing external surface )
www.indiandentalacademy.com
49. • PRINCIPLES MEANS OF RETENTION :
• 1.Frictional retention, depends on 4 factors:
• a)Surface area of contact between tooth structure and
restorative material. Greater surface area produces a
greater frictional component of retention.
• b)More opposing walls / surfaces involved greater
retention and a more stable restoration within the
preparation.
• c)Parallelism & non– parallelism, a higher degree of
parallelism between opposing walls. Higher convergence
of walls – in intracoronal preparation. Higher divergence
of walls – in extra coronal preparation, provides a greater
locking ability of the tooth to the restorative material.
• d)Proximity : bringing the material closer to tooth
structure during insertion will increase the frictional
retention.
www.indiandentalacademy.com
50. • 2.Elastic deformation of dentin :
• Changing position of dentinal walls & floors microscopically
by using condensation energy within the dentin’s
proportional limit, can add more gripping action by the tooth
on the restorative material. This occurs when the dentin
regains its original position while the restorative material
remains rigid thereby completely obliterating any remaining
space in the cavity preparation.
• 3.Inverted truncated cones (or) undercuts.
• 4.Dovetail : This is a purposeful modification in outline form
in some cases but usually extension for prevention will
create a dovetail outline.
• 5.Mechanical interlocking with cements counteracts pull
due to sticky foods.
www.indiandentalacademy.com
51. Means of retention for materials.
Amalgam.
Primary Retention features.
1. Mechanical locking into the surface irregularities
2. Preparation of vertical walls which converge
occlusally
3. Special retentive features such as locks, grooves
pins steps and amalgapins
4. Bonding of the amalgam (Optional)
Retention locks.
They are placed in the axiogifacial and axiolingual line
angle(S p 706)
www.indiandentalacademy.com
52. • Groove extensions.
• Occlusal dove tail.
• Secondry retention form.
• Slot.
• A slot is a retention groove in dentin whose length is in
a horizontal plone
• Slot retention may be used in conjunction with pin
retention or as an alternative to it .
• Outwaire et el reported pin retained amalgam has
more tendency to slip whereas slippage does not
occur in slots.
• Preparation.
• Using a No. 33 ½ bur a slot is placed in the gingival
floor 0.5mm www.indiandentalacademy.com
axial of the DEJ.
53. • Slots in the gingival floor may be used to
provide additional retention in an extensive
proximal box. Slot dimension will depend on
the size of the proximal box.
• Normal Dimensions of the slot
• 0.5mm to 1mm- Deep gingivally
• 2 mm to 3 mm - Length
faciolingually
• 0.2mm to 0.3mm - Inside DE
Junction.
www.indiandentalacademy.com
54. • Groove.
• In classII, III and Class V
• Features.
• Prepared b y ¼(0.5mmdiameter) round bur.
• Groove is prepared by placing the bur at the line
angle cutting half the depth of bur i.e.,o.25mm..
• Cove.25 mm into dentin.
• They are`palced inj cl III amalgam
• They are palced at axiogingivofacial and
axiogingivolingual point angles. .
www.indiandentalacademy.com
55. • Retention of amalgam in special situations.
• In Box type preparation.
When restoring a small, cavitated, proximal lesion in
tooth, a proximal box preparation is recommended.
To maximize retention, preparations with facial and
lingual walls that almost oppose each other are
advised.
• To compensate for the lack of an occlusal
preparation, the proximal retentive locks should have
a 0.5mm depth at the gingival point angle, tapering to
a depth of 0.3mm at occlusal surface
• In slot type preparationsentive grooves are given at
the occlusoaxial and gingivoaxial line angles.
•
www.indiandentalacademy.com
56. • Cusp capping.
• Cusp reduction significantly decreases
retention form caused by loss of height of
vertical walls. When additional retention is
indicated, slots and pot holes can be
prepared along the gingival floor, 0.2mm
pulpally from the ‘DE’ junction.
www.indiandentalacademy.com
57. • Pin retained amalgam restorations.
• DEFINITION
• A Pin retained restoration may be defined
as any restoration requiring the placement of
one or more pins in the dentin to provide
adequate retention form.
www.indiandentalacademy.com
58. • INDICATIONS
• For restoration of mutilated and badly broken down teeth
especially in young patients where the gingival lines are still
high, where massive tooth preparations necessitated by cast
restorations are contraindicated, pins are required for
auxiliary retention.
• In badly broken down teeth, prior to endodontic or
orthodontic treatment, pin retained restorations are placed as
a transitional restoration to act as a build up for rubber dam
application or band attachment.
• As a foundation for partial or full veneer cast restoration or
metal ceramic restorations, thereby saving considerable
amount of tooth structure by eliminating the need to remove
undercuts.
• As a provisional restoration in teeth with questionable
prognosis endodontically or periodontally, until a definitive
prognosis is established.
• In preparations where adequate retention form cannot be
established with slots, locks or undercuts, pins are used as a
means of providing auxiliary retention.
www.indiandentalacademy.com
59. CEMENTED PINS FRICTIONAL GRIP THREADED PIN
• .
Pin channel is larger in diameter than 1. Pin channel is slightly narrower 1. Pin diameter is narrower than
pin. in diameter than pin. that of the pin.
Pin Channel Diameter 2. Pin Channel Diameter 2. Pin channel diameter
- 0.020 0.021 0.027
- 0.021 3. Pin diameter 0.021
Pin Diameter 0.022 0.018
- 0.025 It is 2-3 times more retentive than 0.013
- 0.020 cemented pin. 3. Pin diameter
0.031
0.023
0.020
0.015
It is 3-6 times more retentive than
cemented pin.
www.indiandentalacademy.com
60. • FACTORS AFFECTING THE RETENTION OF THE PIN IN
DENTIN AND AMALGAM
• Type of pin: In order of retentiveness, self-threading pin is
most retentive, friction lock pin is intermediate and cemented
pin is the least retentive.
• Surface characteristics: Retention of the pin in amalgam is
influenced by the number and depth of elevations in the pin.
Therefore, self-threading pins are most retentive.
• Orientation of the pins: Retention of the pins is increased by
placing them in a non-parallel manner.
• Number of pins: Within limits, increasing the number of pins
increases the retention in dentin and amalgam.
• Pins placed closer than 2 mm in dentin to each other in one
tooth will result in
• Crazing of dentin and increased potential for fracture.
• Decrease in the amount of available dentin between the pins.
• Strength of amalgam restoration decreases.
www.indiandentalacademy.com
61. • Diameter of the pins: Within limits, as the
diameter of the pin increases the retention in
dentin and amalgam increases.
• Extension into dentin and amalgam: Pin
extension into dentin and amalgam greater
than 2 mm is unnecessary for pin retention
and contraindicated to preserve the strength
of the dentin and amalgam.
www.indiandentalacademy.com
62. • Amalgam Foundations.
• It is an initial restoartion of broken down tooth . The
tooth is restored so that it will provide resistance and
retention fprms needed for indirect cast restoration.
• It also provide resistance form against forces that
otherwise might fracture tooth structure.
• It does not depend primarily on coronal; tooth
structure instead it rely mainly on secondary
preparation retention features(Pins, slot,coves
and`proximal retention locks.)
www.indiandentalacademy.com
63. • CHAMBER RETENTION :-
• A Nagyar et al has described technique for
developing foundations in multi rooted endodontically
treated teeth. It is recommended only
• Dimension to the pulp chamber is adequate to
provide retention and bulk of amalgam.
• Dentin thickness in the region of pulp chamber is
adequate to provide rigidity and strength to the tooth.
• Extension into the root canal space 2 to 4mm in
recommend when pulp chamber height its 2mm or
less
• When pulp chamber height is more than 6mm no
adavantage is gained from extending into root canal.
www.indiandentalacademy.com
64. • Amalaga pin
• These are circular`chambers that are cut in the dentin
to provide rewsistance and retention of the restoration.
These are also called Amalgam inserts.
• They provide retention similar to self thresded pins.
• It is 1.5 to 2mm in depth and 0.8mm in diameter.
www.indiandentalacademy.com
65. • Cast metal restoration.
• – Principle retentive feature is close parallelism
of longitudinal walls. Small range for
divergence (2-5 degrees / wall) from the line of
draw will enhance retention form (concept of
taper)
• Since exact parallelism create technical
problems in processingl,a slight taper is
desired.
• The average taper is 2-5 degrees.
• The taper can be altered by following afctore
• 1.length of the preparation.
www.indiandentalacademy.com
66. • 3. need for retention.
• Bevels.
• Grooves.
• These are indicated when th eprepaartion walls are
short.
• Groove extensions.
Well defined line angles are also important in
obtaining resistance and retention form.
www.indiandentalacademy.com
67. Secondary modes of retention :
1) Luting cement : fills gap between inlay
and tooth giving a physio chemical
bonding. Physical – Zinc phosphate,
chemical : glass inomer +
polycorboxylate. The exposed cement
dissolves in the oral cavity and so
should not be considered as main
retentive factor.
www.indiandentalacademy.com
68. 2) Grooves : Place two
grooves, one on bucco
axial and other on lingual
axial line angle with #165
bur. It is totally placed on
dentine. Depth of groove
should be 0.3mm at the
expense of buccal and
lingual walls and never at
expense of axial walls.
www.indiandentalacademy.com
69. 3)Reverse Bevel :
It is given on
gingival seat. This bevel has
generally three planes, i)
reverse bevel plane where
inclination is on gingivoaxial
plane which prevents
proximal displacement.
ii) secondly, flat plane made
of dentine.
iii) thirdly ,plane which is
sloping away from the axial
wall made of enamel and
dentine, www.indiandentalacademy.com
this helps in
70. 4) Internal box:
made on the
pulpal floor, which
improves the retention by
4-5 times. this is on the
uninvolved side. it should
not have sharp line and
point angles and definite
walls. This prevents
micromovement of the
inlay. Internal box should
always be reciprocated
with a reverse bevel or
groove to avoid
micromovement.
www.indiandentalacademy.com
71. 5) External box : these are box
shaped preparations opening
to axial tooth surface .they can
be proximal, facial or lingual.
They can be either stepped
occlusally or gingivally.
www.indiandentalacademy.com
72. 6) Roughening of pulpal floor :
at specific areas of tooth
preparation, esp. in pulpal
floor, is done for more
retentive and laterally locking.
irregularities should have no
frail or undermined enamel.
Creating different levels out of
flat, dished up, gingival or
pulpal floors could change a
mechanically negative
situation into a positive one.
www.indiandentalacademy.com
73. • 7) Precementation grooves : after casting
make grooves on the walls of the inlay
and/or grooves on the cavity wall exactly
opposite. This will house with solid mass of
cement which helps in good retention
www.indiandentalacademy.com
74. 8)Electrolytic etching of inlay :
This gives hinge like projections.
Procedure : Protect proximal and occlusal
surface with sticky wax and keep it in the
electrolyte solution of 0.5 normal nitric acid.
Inlay is kept in anode and metal
with increased EMF as cathode.(316
stainless steel )
www.indiandentalacademy.com
75. current causes microporosities on fitting
surface which enables the luting cement to
flow into it for better retention. This
process takes place for around 10 to 15
mins.
www.indiandentalacademy.com
76. It is usually advantageous to use a diamond stone for
preparing the tooth for a composite restoration. This
results in a roughened prepared surface, which
increases the surface for bonding.
• The modified preparation for composites conserve
more tooth structure because retention is obtained
primarily by micromechanical adhesion to the
surrounding enamel and underlying dentin, rather than
by preparation of retention grooves or coves in dentin.
www.indiandentalacademy.com
77. ADVANTAGES OF ENAMEL
BEVEL
The ends of the rods are more
effectively etched than
otherwise only the sides of the
enamel rods are exposed.
Increase in etched surface
area results in a stronger
enamel to resin bond, which
increases retention of the
restoration and reduces
marginal leakage and marginal
discoloration.
Incorporation of cavosurface
bevel may enable the
restoration to blend more
esthetically with the coloration
of the surrounding tooth
structure.
www.indiandentalacademy.com
78. Even recognizing these
advantages, bevels are not
usually placed on the
occlusal surfaces of
posterior teeth or other areas
of potential heavy contact
because a conventional
preparation design already
produces end on etching of
the enamel rods by virtue of
the enamel rod direction on
occlusal surfaces
• Bevels are not placed on
proximal margins if such
beveling results in excessive
extension of the cavosurface
margins.
• Therefore this design is rarely
used for posterior composite
restorations.
www.indiandentalacademy.com
79. • For restoration of large carious lesions, wider bevels
or flares and retention grooves, coves or locks may be
indicated (similar to amalgam) in addition to the
retention afforded by the adhesive procedures.
• Class III
• The boxlike design is considered a part of retention
form.the external walls are retentive because of
opposing wall parallelism or slight undercuts.
• Retention groove may help in minimizing the potential
negative effects of polymerization shrinkage and
increae retention.. It is palced .25 bb bisecting external
wall and axial wall. It is not indicated in bevelled
conventional preparation.
www.indiandentalacademy.com
80. • Coves are prepared with no.1/4 bur at the axioincisal
point angle with the bur oriented in a similar angle,0.2
mm inside the DEJ and 0.25mm deep.
www.indiandentalacademy.com
81. • Cleass IV.
• Gingival and incisal
retentive undercuts may
be indicated in large class
IV preparations in which
rounded undercuts are
placed in the dentin along
line angles and into point
angles wherever
possible.
www.indiandentalacademy.com
82. • Retention form is provided primarily
by the micromechanical bonding of
the composite to the enamel and
dentin.
• Additional retention may be
obtained by increasing the width of
the enamel bevels or placing
retention undercuts.
• If retention undercuts are deemed
necessary prepare a gingival
retention groove using a no ¼
round bur. It is prepared 0.2mm
inside the DEJ at a depth of 0.25
mm and at angle bisecting the
junction of the axial wall and
gingival wall.
www.indiandentalacademy.com
83. • Class V.
If retention grooves are necessary they are
prepared with a no.1/4 bur along the full length
of the gingivoaxial and incisoaxial line angles.
• For bevelled conventionalGroove retention
usually is not indicated when the periphery of
the tooth preparation is located in enamel.
Many of these larger preparations will be a
combination of beveled enamel margins and
90-degree root-surface (non enamel) margins,
with the root surface areas having groove
retention .
•
www.indiandentalacademy.com