Lost-wax technique- definitions and steps including pictures
From spruing, investing, burnout, casting, to finishing and polishing
Source: Contemporary Fixed Prosthodontics
Done by: Lina Nachawati
Lost-wax technique- definitions and steps including pictures
From spruing, investing, burnout, casting, to finishing and polishing
Source: Contemporary Fixed Prosthodontics
Done by: Lina Nachawati
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.
Biomechanics in fixed partial prosthodontics/ orthodontics trainingIndian 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.
fixed prostodontices slight for second year tripoli university prepared by d.sirag al-hamadi (chlinical demonsatror in fixed prostodonic departmeant (2009-2012)
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.
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
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.
Biomechanics in fixed partial prosthodontics/ orthodontics trainingIndian 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.
fixed prostodontices slight for second year tripoli university prepared by d.sirag al-hamadi (chlinical demonsatror in fixed prostodonic departmeant (2009-2012)
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.
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
4. Terms and Concepts
Fixed dental prosthesis
(Fixed bridge): any dental
prosthesis that is luted,
screwed or mechanically
attached or otherwise securely
retained to natural teeth,
tooth roots, and/or dental
implant abutments that
furnish the primary support
for the dental prosthesis
Descriptive terminology
(modifiers) expressed as
adjectives to each fixed dental
prosthesis may include such
items as the method of
retention, composition, nature
of support, design
characteristics, and/or form
of anchorage
Fixed
bridge
Metal ceramic restoration
(porcelain fused to metal
restoration): a tooth or/and
implant retained fixed dental
prosthesis that uses a metal
substructure upon which a
ceramic veneer is fused
Crown vt (12c): to place on
the head, as to place a crown
on a tooth, dental implant or
tooth substitute—usage :
implies fabrication of a
restoration for a tooth on a
natural tooth, dental implant
and/or dental implant
abutment
Porcelain
fused to
metal
crown
DTPT341 Fixed Prosthodontics I
5. Principles of Tooth Preparation
“Optimal Restoration”
Esthetic
Mechanical
Biological
Biological
• Conservation of tooth structure…
• Avoidance of overcontour…
• Supragingival margins, Equigingival margins
• Harmonious occlusion
• Protection against tooth fracture
Mechanical
• Retention form…
• Resistance form…
• Deformation
Esthetic
• Minimum display of metal
• Maxinum thickness of porcelain
• Porcelain occlusal surfaces
• Subgingival margins…
DTPT341 Fixed Prosthodontics I
-Preserve tooth structure
-Retention & Resistance
-Structural durability
-Marginal integrity
-Preserve periodontium
6. To Preserve Tooth Structure
• Remove disease tooth structure
• Remove unsupported tooth structure
• Remove sound tooth structure(Why?
>>Occ. clearance, axially, remove undercut
in POI, int. surface features)
Retention & Resistance
• Taper(Ideal taper ?
>>Many factors)
• Freedom of displacement
• Length
• Diameter
• Internal surface
(Groove, pin, box)
• POI
Structural Durability
• Occlusal reduction
• Functional cusp bevel
• Axial reduction
Marginal Integrity
• Chamfer(c) Metal Margin
• Heavy ChamferPFM
• Shoulder(d)PFM, All Ceramic
• Radial Shoulder~shoulder
w/rounded int. line angle
• Shoulder w/bevel(e)PFM
w/metal collar
• Knife edge(a) Lower Molar
To Preserve
Periodontium
• Finish line at enamel
• Supragingival or equigingival
margin if possible
• 2 mm above bone
5 Principles
DTPT341 Fixed Prosthodontics I
8. Factors Influence Retention & Resistance
Force
-Magnitude
-Direction
(most in POI)
-Food
stickiness
-Surface area
to food contact
Length
-Retention
increases with
an increase in
the length of
the abutment
tooth
Taper
-Retention
increases as
the walls of
the abutment
preparation
approach
parallelism
-Degree
10(Ant.) ,
14(Premolar),
19-22(Molar)
Shape
-The more
completely the
restoration is
seated, the
better the
retention
-Less stress =
round int. line
angle, more
bonding
w/cement
Surface
Texture
-slightly
roughened
surfaces
contribute to
stronger bond
-grooves, pins,
boxes
Diameter
-Retention
increase with
an increase in
the diameter
of an
abutment
tooth
Luting
Agent
-more %Au
content metal,
weaker bond
w/cement
-adhesive
resin cement =
most retention
DTPT341 Fixed Prosthodontics I
POI
Freedom of
displacement
Food+Tooth preparation +Cementation
Retention & Resistance
9. Conservation of Tooth Structure
Tooth Reduction
-Incisal/Occlusal reduction
-Proximal reduction
-Buccal&Lingual reduction
=(Two plane preparation)
***ถ้ากรอแค่ plane เดียว หรือ กรอมากเกินไป
จะกินเนื้อฟันที่ดีมากเกิน
>>ทาให้เนื้อฟันบาง และเป็นสาเหตุที่ทาให้เสียวฟัน
Nature of
Dentine
-young teeth
are more
sensitive,
have larger
pulps, and are
wetter than
older teeth.
DTPT341 Fixed Prosthodontics I
Structural Durability
Retention &
Resistance
Preserve Tooth
Structure
10. PFM
• The porcelain fused to metal restoration consists of layer of porcelain
bonded to a thin metal casting, or coping which fits over the tooth
preparation
Advantages
Greater strength than porcelain alone
Greater longevity than porcelain alone
Can replace of missing teeth with fixed bridges
Can be used in a wider variety of situations
High rate of Long Term Success
Having a nearly natural appearance
Disadvantages
Cosmetic appearance is excellent,
not as aesthetically pleasing as other types of crowns
Gingival inflammation causing gray line compared to porcelain
crowns and Porcelain-Fused-to-Gold Crowns
Without the space for an adequate thickness of porcelain,
the restoration will be poorly contoured,
or poorly matched to the shade of adjacent
The crown’s porcelain can chip or break off
The porcelain surface of the crown can significantly wear those
teeth that bite against it
การดูแลรักษา อายุการใช้งาน
DTPT341 Fixed Prosthodontics I
11. Avoidance of Overcontour
Preparations for porcelain fused to metal crowns
-Labial and incisal surfaces
Incisal & Labial grooves + 2 planes preparation
>>If one plane … bad shade match
or an overcontourd “block , overtapered and too close to the pulp
-Incisal reduction parallel to incisal edge
-Gingival reduction is carried around
the labioproximal line angle to a point 1 mm.
-Lingual surface is reduced a minimum
of 0.7 mm. of clearance with the opposite teeth
-Finish line on proximal surface is a chamfer
DTPT341 Fixed Prosthodontics I
Structural Durability
Retention & Resistance
Preserve Periodontium
12. Finish Line Location
-Subgingival margin ทาเพื่อความ สวยงาม ex.
Labial surface ของฟันหน้า
-Finish line ห่างขอบกระดูกเบ้าฟันมากกว่า 2 มม.
เพราะระยะดังกล่าวเป็นที่อยู่ของ Biologic width
-การวาง Finish line และขอบสิ่งบูรณะไว้บริเวณนี้ย่อม
ส่งผลให้เกิดเหงือกบวมอักเสบ กระดูกละลายต่าลง และเกิดร่องลึกปริทันต์
***If possible>> Finish line ควรอยู่ในตาแหน่งที่ทันตแพทย์
สามารถเข้าถึงง่ายและขอบเขตของสิ่งบูรณะควรอยูในบริเวณที่
ผู้ป่วยทาความสะอาดได้สะดวกทั่วถึง Supragingival margin
or equigingival margin
DTPT341 Fixed Prosthodontics I
Biological
Esthetic
13. References
• THE GLOSSARY OF PROSTHODONTIC TERMS
• Fundamentals of Fixed Prosthodontics, Shillingburg, Jr.,Hobo,Whitsett.
• Simon H, Yanase RT. Terminology for Implant Prostheses. Int J Oral Maxillofac
Implants 2003;18:539-43.
• http://www.udent.com/topics/articleid/63/porcelain-fused-to-metal-crown.aspx
• http://www.scdlab.com/porcelain-fused-to-metal-restorations
• http://www.gj.mahidol.ac.th/thai/index.php?option=com_content&task=view&id=4
2&Itemid=37Harold R. Horn, Practical consideration for successful crown and bridge
therapy
• ผศ. บัณฑิต จิรจริยาเวช, เอกสารประกอบการบรรยายเรื่อง Principle of tooth preparation
DTPT341 Fixed Prosthodontics I