yenepoya dental college n hospital Mangalore final year pg

1. In fixed partial denture

2. Content
• Introduction
• Concepts of crown contour
• Photographic analysis of emergence profile
• Emergence Margin in Periodontally Involved Teeth
• Recording soft tissue emergence profile.
• Emergence profile in ovate pontic.
• Summary
• Conclusion
• References

3. The term “emergence profile” was first used in
1977 by Stein and Kuwata to describe tooth and
crown contours as they traversed soft tissue and
rose toward the contact area interproximally and
height of contour facially and lingually.

4. In 1989, Croll B M it was explained as the
portion of axial tooth contour extending from the
base of the gingival sulcus past the free gingival
margin into the oral environment.
Croll BM. Emergence profiles in natural tooth contour. Part I: Photographic
observations. J Prosthet Dent 1989;62:4–10.

5. 1989 Fugazzotto explained
•emergence profile as the angle at which the tooth comes
out of the supporting osseous structure.
He suggested that a tooth should emerge in a perpendicular manner
from the osseous structure to obtain good periodontal health.
Preparation of the Periodontium for Restorative Dentistry.Tokyo: Ishiyaku Euro America, 1989:17.

6. Glossary of Prosthodontic Terms
•defined it as the contour of a tooth or restoration,
such as a crown on a natural tooth or dental
implant abutment, as it relates to the adjacent
tissues.
The Glossary of Prosthodontic Terms, ed 7. J Prosthet Dent 1999;81:48

7. The location and emergence of the prosthetic
margin are crucial to the :
• gingival health and maintenance of oral hygiene.
• esthetic objectives

8. A proper emergence profile will help avoid
swelling and inflammation of soft tissue
and conversely will prevent the unsightly dark
spaces in the area near the gums and between
the teeth.
Croll BM. Emergence profiles in natural tooth contour. Part II: Clinical
considerations. J Prosthet Dent 1990;63:374–379

9. Emergence profiles are the most crucial link between tooth
form and gingival health.
The microorganisms that cause periodontitis and gingival
inflammation can colonize on these surface areas.
Careful attention to developing the proper emergence
profile in the definitive restoration will reduce not only
plaque retentive areas but also iatrogenic inflammation
Restorative margin placement and periodontal health. J Prosthet Dent 1991;66: 733–
736.

10. • Clinical longevity of any prosthesis is directly related in
achieving proper coronal contours.
• This involves close attention to detail between periodontal
and prosthodontic principles during the fabrication of the
prosthesis.

11. • TEN RULES FOR DEVELOPING CROWN CONTOURS IN RESTORATIONS
• Burch, J.G. Ten rules for developing crown contours in restorations. DCNA 1971;15:611-618.
1)Faciolingual crown dimensions- no more than 1mm larger than
the faciolingual width at the CEJ. Possible exception: mandibular
molars and second premolars.

12. • 2)Facial contours- all facial contour crests are in the gingival
third, and should not bulge more than one-half mm beyond
CEJ.

13. • 3)Lingual contours- greatest convexity at gingival 1/3
except mandibular molars and sometimes mandibular second
premolar, where greatest convexity is found in the middle 1/3 of
crown.

14. 4)Proximal contact points- in the occlusal 1/3 of crown.

15. 5)Proximal surfaces
Proximal surface is flat or slightly concave buccolingually as
well as occlusocervically.

16. • 6)Axial transitional line angles-
• straight between the proximal contact point and the CEJ,
• with the exception of the lingual line angles of maxillary
molars, where there may be a slight convexity.

17. • 7)Marginal ridges-
should be the same height for adjacent teeth. The facial ½ of
any tooth is wider than the lingual. Lingual embrasures are
always larger than buccal embrasures when viewed
occlusally

18. • 8)Crown margin-
should be supragingivally except due to esthetics, crown length to
gain adequate retention, root caries, root sensitivity, existing
restorations.

19.
9)Thickness of restoration:
•The subgingival contour has considerable effect upon the
free marginal gingiva and the gingival crevice.
•subgingivally- inadequate contour may not provide for
adequate support for the gingival unit.
•Subgingival contour should support the gingiva, so that the
free marginal gingiva does not tend to form a roll around
the tooth.

20. 10)Crown margin/Bone
• relationship- do not encroach on the biologic width.
• Contour of the crown should not be bulky as it might tear
circumferential fibres and undue stress might be exerted on
gingiva beyond their physiologic limits of tolerance.

21. DESIGINING CROWN CONTOUR IN FIXED PROSTHODONTICS:
A NEGLECTED ARENA Annals and Essences of (DentistryVol III Issue 1 jan- Mar 2011
Some common clinical problems
•improper axial, facial or lingual contour of crown.
•Contour of artificial crown are not generally made self protective.
•Overcontouring leads to food trap and hence complicating the
periodontal status.
•Interdental papilla is often neglected due to improper design of
interdental space.
•These shortcomings can be fulfilled by following the general
principles of crown designing.

22. current controversies in axial contour design: JPD 1980 vol 44 pg 536
• Traditional concepts of crown contour:
1) Food deflection theory (Wheeler) 1961.
He advocated that artificial crowns should have convexities
in their cervical third which will help in deflecting food
away from the free gingiva.

23. • Herlands et al questioned the rationale of the
food deflecting contour concept. He noted that
• When prepared tooth is left uncovered for an extended
period of time, complete lack of contour is usually seen
but the surrounding gingiva is usually healthy.
current controversies in axial contour design: JPD 1980 vol 44 pg 536

24. Later found
Crownsmadewith Wheeler’sconcept
Overcontoured
Food impaction
gingival inflammation
current controversies in axial contour design: JPD 1980 vol 44 pg 536

25. • current controversies in axial contour design: JPD 1980 vol 44 pg 536
2)Muscle action theory (1962)(Herlandset al and
Morris).
• They emphasized on muscle moulding and
cleansing, rather than food impaction.
• This theory upholds the principle of constant
cleansing and molding action by the muscles of the
cheeks, lips and tongue.
• Muscle action can be impaired when the necessary
intimate contact is prevented by an over contoured
crown or bone.

26. Mortan L. Perel (1971)
studied the relationship between axial tooth contour and marginal
periodontium on dogs.
• Procedures producing undercontours and overcontours on buccal
and lingual crown surfaces on surrounding marginal gingiva.
were performed.
• Clinical and microscopic evaluations were made in respect to the
condition of the marginal periodontium and the crevicular areas,
He concluded that:

27. 1. Undercontouring of axial surfacesdid not produceany
significant changesin healthy gingivae.
2. Overcontouring of axial surfaces, on theother hand,
produced inflammatory and hyperplastic changesin the
marginal gingivae. Such changeswereseen both clinically as
well ashistologically, after 4 weeks.

28. 3) Plaque retention theory
• According to this theory
Crown contours should be such that it should not
provide any niche for plaque retention and should
promote self-cleaning.
• Design of axial contour should be based on muscle-
action theory

29. …
4) Anatomic/Biologic theory
• It was proposed by Kraus et al. in 1969.
According to this theory:
• A biologic contour is a self protective contour to the
supporting tissues and defended the gingival unit,
attachment apparatus, and protected bone from trauma
and irritation.
• Improper contour often induced early breakdown of the
supporting structures and tooth tissue, resulting in
premature loss of teeth.

30. 5) Theory of access fororal hygiene
• Based on theconcept that plaqueistheprime
etiologic factor in cariesand gingivitis.
• Crown contour should facilitateand not hinder
plaqueremoval.

31. 4 guidelines
contouring crowns to accessfor oral hygieneare:
1)Flat (and not fat) buccal contours.
2)Open embrasures.
3)Location of contact areas.
4)Fluted or barreled out furcations.

32. …
1)Buccal and lingual contours - flat, not fat
The normal buccal-lingual width of a non-restored natural tooth
is approximately 1 mm wider at the maximum buccal-lingual
dimension (height of contours) than the buccal-lingual width
at the CEJ.
.
Therefore there is a minimum infrabulge so that muscle action
cleansing that might be present can be operable

33. • Buccal bulge on a normal tooth is no more than 0.5 mm
prominent from the CEJ
• There is also a gradual sloping, giving a flat appearance.

34. Sharp angles or abrupt convexities or concavities should
be avoided to maintain tone of musculature of lips, cheek
and tongue.
The facial and lingual surface contours should have
gradual curvatures in all directions to facilitate the
rubbing and cleaning function of the lips, cheeks, and
tongue

35. • Plaque retention on the buccal and lingual surfaces
occurs primarily at the infrabulge of the tooth.
• Reduction or elimination of the infrabulge would
reduce plaque retention.

36. 2. Open embrasures:
To allow easy accessto theinterproximal areafor plaquecontrol.

37. • The faciolingual width of the contact area is generally
in harmony with faciolingual width of the interproximal
papilla.
• lnterdental papillae should not be impinged by
interproximal surface.

38. • An overcontoured embrasure will reduce the space
intended for the gingival papilla.
• The result is a broadening of the col area, causing
pressure and irritation on the papilla.
• This also inhibits effective oral hygiene

39. If the faciolingual width of the contact area is
wider than the papillla, an overhang is created
which will permit plaque accumulation.

40. • . Spaces between interproximal areas which are
created due to gingival recession should be
closed toward the papilla without impinging
them.

41. :3. Location of contact areas
Contactsshould behigh( incisal third ) and buccal to thecentral
fossa( except between thefirst and second molars).
Thiscreatesalargelingual embrasurefor optimum health of the
lingual papilla.

42. • A rationale for comparison of plaque retaining properties in crown systems. J Prosthet Dent.
1989,62:264-9.
Hazen and Osborne have warned of the consequences
of an ‘‘oversized’’ col resulting from broad
(buccolingual) contacts.
• The col is a nonkeratinized area which is thought to
be more susceptible to plaque.
• The broad contact produces a larger col, thereby
leading to increased chance of inflammation.

43. Ramfjord S. Periodontal aspects of restorative dentistry. J Oral Rehabil 1974;1:107
• Ramfjord recommends placement of contact
areas as far occlusally as possible to
facilitate access for interproximal plaque
control.

44. 4. Furcations should be “fluted” or“barreled out”.
• Thefinal restoration should not follow theanatomy of theoriginal
clinical crown, but should be an extension of the contours of
the periodontally exposed roots.
Triangular region created by therootsand thecervical bulgeis
eliminated

45. • The concept of fluting into molar furcations is based on the desire
to eliminate ‘‘plaque traps’’ and facilitate plaque control
This triangular region is the most difficult area to maintain in a
plaque-free condition with conventional brushing techniques.

46. • In 1989, a photographic analysis of natural
teeth by Croll confirmed that most emergence
profiles are relatively straight as opposed to
convex or concave. If a restoration introduced
a convexity or concavity where it didn’t
belong, the unnatural contour might trap
plaque or otherwise disrupt the gingiva.
Croll BM. Emergence profiles in natural tooth contour. Part I: Photographic
observations. J Prosthetic Dent 1989;62(1):4-10.

47. • Several hundred extracted teeth werephotorgaphed
for thisstudy.
• Photographsweremadewith a105 mm macro lens
to minimizeparallax.

48. • Anatomic observation were also recorded from
1)Intraoral photographs of natural teeth.
2)Photographs of mounted diagnostic casts in
cross section.
3)Radiographs of teeth made by using a parallel
cone technique in vivo.

49. • A straight edge placed on the photogragh
provides a gauge to evaluate relative
straightness, convexity, and concavity of the
tooth structure.

50. • Observation were made to establish the
anatomic norm for emergence profiles at
specific sites through out the dentition for
developing a basis of accurate reproduction in
clinical dental restorations.

51. Convexitieswerediscovered palatally in themaxillary
incisorsand lingually on mandibular incisorsviewed
mesiodistally.
Maxillary incisor Mandibularincisor

52.  Maxillary canine,
anatomic crown.
Maxillary canine, sectioned
diagnostic casts.
Maxillary canine,
gingival overlay.
41
2
A comparison of figuresA, B and C indicatesthat most of thebuccal surfaceemergence
profileof theanatomic crown may besubmerged below thefreemarginal gingiva,
extending only 1 mm into theoral cavity.

53. Palatal convexity in maxillary canine
theconvexity on thelingual surfacemay also besubmerged below thefreemarginal
gingivapalatally.

54. Theemergenceprofileoften extendsbuccally and lingually to the
height of contour of thecrown of atooth.

55. Interproximally, theemergence
profileextendsfrom thebaseof
thegingival sulcusat thecement
enamel junction (CEJ) to the
contact area.
Emergenceprofileof maxillary first premolar,
buccal view

56. Thebuccal and palatal surfacesof maxillary posterior teeth
present straight emergenceprofilesin thegingival third of the
anatomic crown.

57. Restorationsmadewith convexitiesin thegingival third should
beconsidered overcontoured.
Over contoured buccal and lingual surfaces.

58. Concavitieswereregularly observed on the:  distal surfacesof
canines
 mesial surfacesof maxillary first premolars
Interproximal view b/n maxillary caninen 1st
premolar.
Theconcaveemergenceprofileof each tooth present amirror imageof theother.
Croll BM. Emergence profiles in natural tooth contour. Part I: Photographic
observations. J Prosthetic Dent 1989;62(1):4-10.

59. Thelingual surfacesof mandibular posterior teeth havestraight
emergenceprofilesfrom theCEJto pointsonehalf to two thirdsof
thedistanceto theocclusal surface.
Mandibular second premolar,
anatomic crown.
Mandibular second premolar, sectioned
diagnostic cast.

60. Interproximally, themesial surfaceemergenceprofileof
maxillary first molarsisconcavebelow thecontact area.
Maxillary first molar, buccal view, concaveemergenceprofilebelow mesial contact on right.

61. Theemergenceprofileon thebuccal surfaceof themandibular
posterior teeth isoneof threestraight linescomprising the
entirefacial profile. Restorationsmadewith thesefacial
contoursarenatural in appearance.

62. Intraoral view showing straight emergenceprofilesin thebuccal vestibuleof mandibular
posterior metal ceramic restorationsfollowing patternson contoursin natural teeth.

63. Radiographsareuseful to visualizetheinterproximal emergenceprofilesof one
tooth asit relatesto adjacent teeth and theemergenceprofileof completed
restorations.
In Interproximal black trianglescan beidentified radiographically, with thebase
formed by theboneand theother sidesformed by theadjacent teeth.

64. A radiograph of acompleted restoration having retainerswith
straight interproximal emergenceprofilescreatesblack
triangular spacesand adequateembrasurespacesthat duplicate
themorphology of natural teeth.

65. A comparison of thetwo demonstratestherelationship of interproximal
emergenceprofilesof maxillary incisor teeth seen clinically with aradiograph.
.
.
Radiograph of samemaxillary incisorsdemonstrating straight emergenceprofiles
below long contact areasextending to CEJ.

66. Metal ceramic crownswereinserted with
long contact areasand straight
interproximal emergenceprofilesfor
natural looking restorations, while
closing theinterproximal gap.
4 maxillary inicisorsafter periodontal
surgery prepared for metal ceramic
crownswithout interproximal papillas.

67. When thecontact areasarelong occlusogingivally, thenormal
emergenceprofileon thepalatal surfaceprovidesawideopen
gingival embrasureto support thetissuein itsproper
relationship to therestoration and to facilitatehygiene
procedures.

68. Concluded that with afew exceptions, teeth
havestraight emergenceprofilesin thegingival
third.
Burney M. Croll
Emergence profiles in natural tooth contour. Part I: Photographic
observations: Burney M. Croll; JPD vol 62 1989

69. • Emergence profiles in natural tooth contour. Part II: Clinical considerations:
Burney M. Croll; JPD vol 63 1990
• confirmed the straight emergence profile as the norm in
naturally occurring axiogingival tooth contour.
• Observations supporting a straight emergence profile
as the normally occurring tooth morphology
approximating the gingival sulcus, based on
photographic measurment ,are a departure from
traditional concepts by wheeler and other authors.

70. • Thecurved transition of axial tooth contour at the
height of contour isnot alwayslocated at the
gingival onethird.
• Interpreting emergenceprofilesasgeometric shapes
can provideguidelinesfor oral hygiene, restoration
design, and tooth preparation.

71. A straight lineand acurvemeet only at onepoint, the
tangent.
•Conversely, astraight lineand aflat emergenceprofile
can beadapted to oneanother.

72. • Theemergenceprofileaffectstheconvenienceand effectivenessof
oral hygieneprocedures.
• Toothbrush bristlesand tooth picksused in conjunction
with handlessuch asPerio-aid devicearestraight in
profile.

73. • Restorationsdesigned and placed with straight
emergenceprofilesin thegingival one-third provide
thepatientswith ashapethat isaccessibleand
facilitatesoral hygiene.
• Thissamerationaleisapplicablein theconvex
tissue-facing surfaceof themodified ridgelap,
recommended by Stein, with optimal contact of the
dental floss, improving oral hygiene.
Emergence profiles in natural tooth contour. Part II: Clinical considerati
The Journal of Prosthetic Dentistry 63, Issue 4, April 1990, Pages 374–379

74. • A straight emergenceprofilewill enableeffective
reaching to thedepth of thesulcusin closecontact
with thesurfaceof therestoration.
• Thisisespecially desirableon thesurfaceof the
tooth beyond thecavosurfacemargin, to facilitate
removal of theaccumulated microbial plaque.

75. • If theemergenceprofileof therestoration is
convex in thegingival one-third, it is
possible, but inconvenient, to removethe
bacterial plaqueon thetooth surface
contacting thegingival sulcusbelow thepoint
of tangency.

76. Thelingual surfacesof mandibular incisorsprovidean example
whereaconvex emergenceprofilein thegingival third iscommon.
Lingual convexity below the
gingival tissue.
Convexity abovethegingival tissuewith thetooth
extruded and gingival recession creating aniche,
difficult to keep clean.

77. Thecalculusand bacterial plaqueaccumulated on the
surfacebelow thelingually convex emergenceprofileare
evident becauseit isinconvenient for thepatient to
maintain.

78. • A modification of thenatural tooth can createasurfacethat is
moreeasily maintained by thepatient.
• Specifically, thelingual surfaceof mandibular incisorsmay be
restored with astraight emergenceprofile.

79. Straight emergenceprofileselected for lingual surfaceof mandibular
anterior restoration to facilitateoral hygiene.

80. • If thedentist choosesto extend thecontact areabetween
anterior teeth from theincisal embrasureto alevel of the
gingival papillafor esthetics, thelingual embrasuremust be
wideenough for accessto thegingival tissueunder the
contact areafrom thelingual surface.

81. When viewed from thefacial surface, themandibular incisors
havestraight interproximal emergenceprofilesthat begin at the
end of along contact areaand extend to theCEJ
Relationship of natural anterior teeth-contact areas
and gingival tissue.

82. Sectioned diagnostic castsreveal aflat facial emergenceprofileof
mandibular anterior teeth extending to apoint midway on the
facial surfacewhen viewed from theinter proximal aspect.

83. If restorationsfollow thispattern, they can beesthetic and allow
convenient interproximal threading of dental floss.
Mandibular anterior teeth with long
contact areaand straight emergence
profile.
Mandibular anterior teeth with long contact
areaand straight emergenceprofileon
pontic of mandibular lateral incisor.

84. Similar to themaxillary canine, themandibular caninehasa
concavity below thecontact areaon itsdistal surface.

85. • Tooth preparationsmust bedesigned to accommodate
dimensional requirementsof restorativematerialswithin the
limitsof theemergenceprofile.
• Depth cut” controlled shoulder preparationswith ahollow-
ground bevel arean approach that meetstheserequirements.
• Hollow Ground (Concave) Bevel: Allows more space for the
cast material bulk Used to improve retention and resistance to
stresses

86. “Theemergenceanglemadeby theemergenceprofile
and thelong axisof thetooth is+15 degrees.

87. On thebasisof mathematical axioms, Kuwata
concluded that if thepath of insertion wasparallel to
thelong axisof thetooth, all metal ceramic
restorationswith cavosurfacebevel angleslessthan
35 degreeswith thepath of insertion should have
metal collarsto prevent over contouring and opaque
exposure.

88. If adequatespacehasbeen created for therestorative
materialsduring tooth preparation, retainersof fixed
partial denturescan bemadewith suitable
emergenceprofiles.

89.  Selection of thestraight emergenceprofilein designing
artificial crownsfor teeth hasshown to improvethe
effectivenessof oral hygienenear thegingival sulcus.
 Theaxial profileof teeth can beviewed asaseriesof
straight lineswith curved transitions. Reproduction of
thesegeometric patternsfacilitatesfabrication of
restorationsthat appear natural.

90. LABORATORY APPLICATION
Several waxing instrumentshaveaflat surfaceto createaflat
profilein themarginal areaof thewax pattern.

91. Theconvex sideof thewaxing instrumentscan develop
concavecontoursin thewax pattern such asthedistal surfaces
of maxillary caninesand mesial surfacesof thepremolars.

92. • Mounted grinding wheelsand sandpaper diskshave
flat cutting profilesthat can machinestraight
emergenceprofilesand finish restorationsduring
fabrication.

93. • Clinically, thefacial and lingual surfacesof the
restorationscan beeasily evaluated for straight
emergenceprofilewith aperiodontal probe.

94. Interproximally, radiographsprovidethebest pictureto establish that
thedesired emergenceprofileand adaptation between therestoration
and root havebeen accomplished.

95. • Reproduction of thesegeometric patterns
createsrestorationsthat appear natural.

96. The Emergence Margin in Periodontally Involved Teeth

97. • International journal of periodontics n restorative DentistryVolume 13, Number 4, 1993
The Emergence Margin in Periodontally Involved Teeth
• Following periodontol treatment, Periodontally involved
teeth often exhibit elongated clinical crowns that create
esthetic problems.

98. • Prosthetic design may be difficult because
changes in root morphology and angulation
increase the technical demands of creating
parallelism for a common path of
insertion,also the design of the crown margin
and the placement of the preparation's finish
line in relation to the gingival margin could
be difficult, because of esthetic, prosthetic,
and biologic factors.

99. • The precision of the marginal fit and the
emergence profile of the root should be key
concepts in prosthetic construction of
periodontolly treated patients.

100. Two features of importance in preparing finish
lines and prosthetic margins:
• Marginal fit of the crown must be precise
• Restoration margin must follow the direction of
the emergence profile of the root.

101. Feather-edge margin traditionally has been the
preparation of choice, because it allows the
achievement of abutment parallelism with
minimal removal of tooth structure at the marginal
areas.
•This type of preparation margin has some
limitations for metal-ceramic restorations.

102. • 1)the preparation margins are not always
clear and distinct therefore, the dental
technician does not always have a clear
landmark for the position of the finish line in
relation to the gingiva.
• 2)Space is limited for the porcelain in the
cervical area, thus the crown emergence
profile could have some degree of
overcontour.

103. • Shillingburg etal indicated that margins of
metalceramic restorations fit on featheredge
finish lines offer poor resistance to the
distortion that results when the ceramic is
baked onto metal.

104. • International journal of periodontics n restorative DentistryVolume 13, Number 4, 1993
• Busto Garolfo
a new preparation margin, the emergence margin
in prosthetic reconstruction of periodontolly
involved teeth.
Because this type of preparation may help in
maintaining a biologic relation between
restoration and periodontium.
• it is conducive to periodontal health while it
satisfies the patient's esthetic demands.

105. Finish line preparation
• The 50-degree finish line was selected for Periodontally
involved teeth.

106. • Emergence profile of root
A line drawn tangentally to the cementoenamel
junction frequently continues as a coronal
extension of the root

107. • This line continues apically in the root portion of the
finish line and draws the ideal margin of the emergence
profile of the cervical portion of the prosthetic crown.

108. In this manner, vertical or horizontal overcontours and
undercontours gingival margin are avoided.
This emergence profile will have different
angulations, depending on different root anatomy and
the position of the preparation margin along the root
surface.

109. • relatively easy to prepare
• always results in a clear margin
• prevents great tooth loss
• achieves a precise marginal fit without a
visible metal collar
• and can be prepared around all surfaces of
the tooth.

110. • Allows enough space for the metal-ceramic
restoration in the buccal surface, and enough
clearance at the interproximal surfaces of
mandibular anterior teeth for the metal collar
fit, without damaging the biologic sulcular
space.

111. Placement of the restoration margin 1 mm
subgingivally is recommended to avoid root
sensitivity and root caries and to satisfy the
patient's esthetic demands.

112. • When the technician is to be given anatomic indications
of the emergence profile, the impression material should
extend more apically than the finish line preparation to
record the direction and contour of the root emergence
profile.

113. Laboratory procedures
•To obtain an optimal orientation of the
prosthetic profile, and to reach absolute
precision of the marginal fit, every step in the
laboratory procedures performed under the
stereo micros cope at 10 xmagnification.

114. After the final impressions and stone pours are
evaluated, the laboratory work continues with
the exposure of the preparation margins
and the visualization of the root emergence
profile.

115. carving of the wax margin seen under the
stereomicroscope

117. The metal cast must be finished in the traditional way
except at the margin.
metal must be polished until there is enough thickness
for the ceramic layer. The metal finish margin must be
entirely covered by the ceramic layer, but without
overcontour.

118. To avoid the possibility of metal distortion around
the preparation margin, a contra chamfer is made
around the metal margin finish line, the angle of
which increases the metal thickness in the critical
region, preserving the ceramic layer.

119. • Opaque is applied to the metal margin, again
using stereomicroscope visualisation.
show the final results of the emergence margin

120. Case
•A patient presented with extensive caries and tooth
loss in the maxillary and mandibular arches.

121. • After periodontal and occlusal treatment were
completed, final prosthetic restoration was
initiated.
• After the final impressions were taken, stone
casts were mounted in a fully adjustable
articulator, maintaining the same occlusal
relationships as in the provisional restorations..

122. • Then, a centric relation record was taken with
the metal frames and transferred to the
articulator.

123. • After the bisque try-in, position impressions
were taken to remount the casts in articulator
before the prosthesis was finalized..

124. • The intracrevicular margination was precise.

125. • The standard of precision was maintained
also for the fitting surfaces in which the metal
was covered by ceramic layer.

126. • One year later, the periodontal condition was
stable.

127. • This patient had severe periodontal and
prosthetic involvement. During the course of
following periodontal treatment, provisional
prostheses were used to allow periodontal
healing.

128. • Precision of the margins in the provisional
prosthesis was very important to promote
adequate plaque control and healing of
periodontal tissues

129. Provisional restoration finished under the
stereomicroscope to check for prosthetic contour as well
as root profile .This will prevent undercontouring or
overcontouring, either of which would be harmful to the
gingival tissues during the healing phase..

130. Recording the gingival emergence profile after
tooth preparations for fixed partial dentures.

131. Gingival contour and occlusion of restorations are 2 important
factors that influence periodontal health.
•Overcontoured restorations result in food and plaque retention in
the interproximal, facial, and lingual cervical areas. This can lead to
caries, gingival inflammation and gingival hyperplasia.
•Undercontoured restorations may create excessive interproximal
spaces and problems with phonetics and esthetics.

132. •In clinical practices, dies are trimmed to expose
margins of preparations.
•The soft tissue emergence profile that surrounds the
prepared tooth is destroyed in the process.

133. • Modified soft tissue cast for fixed partial denture: a technique
J Adv Prosthodont. 2011 March; 3(1): 33–36. ]
The soft tissue casts have become a popular aid in
fabrication of the cervical contours of the implant
crowns, but their use in a conventional fixed partial
denture also play an important role.
These models have gingival masks which duplicate the
gingival architecture of the involved abutments.

134. • Modified soft tissue cast for fixed partial denture: a technique
J Adv Prosthodont. 2011 March; 3(1): 33–36. ]
Uses:
1) allow the lab technician to see the existing gingival
architecture surrounding the involved abutments and
make corrections in the metal substructure to allow for
proper emergence profile and contour.
2) provide the key to proper ceramic application.

135. • TECHNIQUE
• Abutment teeth were prepared to receive a fixed partial
denture. The impression was made with a polyvinyl-
siloxane material.

136. • The impression was disinfected and poured. After
retrieval of the master cast, impression was washed
thoroughly to prepare it for second pour to fabricate a
modified soft tissue cast

137. • A polymethylmethacrylate based resilient liner carefully
mixed and applied onto the facial and proximal aspects
of the impression surface around the prepared and
edentulous spaces with a small painting brush.

138. • Multiple undercuts in the form of irregular surfaces
prepared to achieve mechanical interlocking in the
gypsum material.

139. • The resilient liner was polymerized by immersing the
liner-applied portion of the impression in the hot water
(60 for 2-4 minutes) as per the manufacturer's℃
instructions.
• The water temperature should not be increased more
than 70 to prevent any dimensional change in the℃
impression.

140. • After complete polymerization of the resilient
liner, remaining portion of the impression was
poured in type III gypsum material .The cast was
retrieved from the impression after setting of the
gypsum material.

141. • This soft tissue cast was used along with master
cast to develop and evaluate ideal axial contours
of the fixed partial denture.

142. Fixed partial denture in place with correct gingival
emergence profile.

143. • Soft Tissue Transfer Models: The Patient-Dentist-Laboratory Connection (Canadian
Dental Association)
Bulky metal substructurefor anterior maxillary porcelain fused to metal bridge

144. • Thisisdueto thelossof referencegingival
architectureduring dietrimming and separation
procedures.
• Theframework can still berelated to thegingival
architecturewith theuseof soft tissuetransfer
models.

145. Recording Technique
• Themetal substructureisseated intraorally and atransfer
impression madeusing:-
dual wash (light/medium body) technique:
- light body impression material (injected around theseated framework
medium body impression material within astock tray
.
Transfer impression incorporating porcelain fused to metal substructure.

146. After theimpression hasbeen made, theinsideof
each abutment retainer isslightly lubricated with a
thin layer of Vaseline.
Pattern Resin ispainted insideeach retainer.

147. • Pattern Resin isused to register thelocation of the
abutmentswithin thesoft tissuemodel. The
dimensional stability of thisresin upon setting,
allowsfor avery accuraterepresentation of the
position of theabutments.

148. • Thegingival mask isthen madeby mixing Coe-Soft
relinematerial into adisposablesyringeand injecting it
around thebridge, and themodel ispoured with die
stone.

149. Properly contoured porcelain of anterior maxillary
bridgework:
on the soft tissue transfer
model respecting the
clinical gingival contour.
intraoral view, respecting
the clinical gingival contour.

150. • Accurate procedure for simultaneous registration of gingival emergence profile and maximal
intercuspal position for metal ceramic restorations. (J Prosthet Dent 2000;83:681-5.)
This article describes a simple and accurate
procedure that can be used to simultaneously
register the gingival emergence profile and
maximal intercuspal position.

151. • After adjusting and seating of the copings, dry
the entire surface of the copings.
• Wetting the sable brush (size 0) with monomer
and picking up the polymer (this is commonly
referred to as the Nealon technique )and
applying the mixture in small increments.

152. • Apply autopolymerizing hard acrylic onto the
occlusal facial surfaces of the copings and onto the
facial free gingival margin
• Avoid painting the acrylic resin into undercut areas.
The undercut area is usually the gingival embrasure
area of the adjacent teeth. When the undercut areas
are large, a small amount of soft wax may be used to
block them out.
The free gingival margin distance from interdental
papilla to interdental papilla should be covered with
Duralay acrylic resin.

153. • After the record is clinically verified, remove
the copings from the patient’s mouth ensuring
that the acrylic resin remains attached to the
copings.
If the acrylic resin does not adhere to the
copings, the procedure should be repeated,
making certain that the surfaces are
roughened and dried before application of
resin.

154. • Remove any excess acrylic resin that interferes with
the seating of copings on the dies and with seating
the dies back onto the working cast.
Articulate and mount the mandibular cast using the
acrylic resin interocclusal record that was made in
the maximal intercuspal position.

155. • Inject low-viscosity polyvinyl siloxane impression
material into the space between the seated dies and
copings and the acrylic resin. The impression material
may be extended onto any part of the working cast for
indexing purposes.

156. • Remove the acrylic resin from the copings and from the
polyvinyl siloxane impression material. If the resin
cannot be easily removed from the copings, it can be
softened by heat in an oven or with a torch, and then
removed. The resin does not adhere to the polyvinyl
siloxane material.
• Complete the porcelain addition and finish the metal
ceramic restorations

158. Tissue sculpturing: An alternative method for
improving emergence profile of anterior
fixed prosthodontics J Prosthet Dent 1999;81:630-3.
• This article described a method for
improvement of emergence profile and soft
tissue health by exerting pressure on tissue
with provisional restorations.

159. • A gradual, controlled hyperpressure can
transform an unfavorable tissue configuration to
favorable.
• This allowed a more natural, functional FPD.
There is also a possibility of closing undesirable
“black holes” through papilla “formation” by
pressuring tissue.

160. • Specific tissue dilation can also be accomplished
with eletrosurgery when removing soft tissue to
create pontic sites.
• Nonsurgical,
• Minimally invasive and safe procedure
• Patient is not exposed to complications of surgery.
• There is no tissue removal.
• Interdental papilla was enhanced or sculptured by
the lateral displacement of the tissue over a residual
ridge

161. Similar hyperpressure procedures have been used for
tissue conditioning before implant placement.

162. • Fabricate a provisional FPD with slight
pontic contact beneath the residual ridge.

163. • Apply gradual, gentle compression over the soft
tissue by adding acrylic resin over the pontic
surface toward the ridge.

164. • The amount of acrylic resin added should not
exceed 1 mm to avoid excessive pressure.
The provisional restoration should be inserted
only after final curing of acrylic resin to
evaluate hyperpressure.

165. • The pressure should be capable of producing a
tissue ischemia without interfering with the fit
of the provisional restoration

166. • Develop a convex shape for the pontic both buccolingually and
mesiodistally.
• This shape allowed easy, accessible flossing, which is critical
for longterm treatment outcomes.
• Highly polish all surfaces, especially the surface contacting the
ridge.

167. • Cement the provisional restoration.
• Recall the patient in 1 week to evaluate accommodation of
the tissue beneath the pontic.
• Remove the provisional restoration during this visit and add
a new layer of acrylic resin to continue the tissue
conditioning.

168. • The amount of resin to be added is judged
through an analysis of the shape of tissue and
esthetics .
• After adding the acrylic resin, polish and
recement the provisional restoration.

169. • Repeat this procedure every week until
final esthetic conditioning.
• An improvement in emergence profile of
the pontic and the appearance of an
extruded pontic from the gingival tissue
can be achieved at this time .

170. • The dentist must be aware of the limit of tissue
resilience, which should be closely monitored.
Strength and direction of pressure are determined by
esthetics.

171. • Make a standard impression after completion of
conditioning to provide a master cast with a
removable artificial gingiva.
• Transfer the tissue shape to the cast. This will
allow the dental technician to fabricate a pontic
with identical final characteristics.

172. Disadvantage
residual ridge deformities types I, II, and III,
according to Seibert. Soft tissue grafts are
indicated for these patients, before conditioning
tissue

173. Dent Update 2012; 39: 407–415
Ovate pontic : A natural look
•The emergence profile of the pontic is especially
important if the bridge is planned in the anterior maxilla
and the patient has a high smile line.
•This pontic design has been proposed to address the issue
of emergence profile aesthetics.
•An ovate pontic design can be defined as one which has
an increased amount of mucosal contact and applies light
pressure to the underlying mucosa in an attempt to
improve aesthetics.

174. Dent Update 2012; 39: 407–415
• The ovate pontic has been suggested as a more accurate
duplication of emergence profile for natural teeth to
provide an esthetic.
• The goal of an ovate pontic is the illusion that the tooth is
emerging from the gingiva with a cuff of tissue
surrounding it on the facial.

175. • The ovate pontic :
• Excellent aesthetics, especially emergence profile.
• Helps to create or maintain the presence of interdental
papilla.
• Reduce the presence of black triangles;
• Avoid alveolar collapse.

176. Ridge Evaluation of Ovate Pontics J esthet restor dent 2013,273-78
•for the ovate pontic to be successful, there must be sufficient
height and width of alveolar ridge
•There are three things we look at in order to decide whether the
ridge is adequate, or if it would need augmentation to
accommodate the pontic.
1)Interproximal height
2)Free gingival margin
3)Facial prominence

177. • Theinterproximal tissueshould bepreserved after theremoval of
atooth.
• It isimportant to preservethesocket size, shape, and thespaceof
thegingival tissuein order to preservethetissueheight.

178. • extracted socket must bepreserved in thesameshapeand
location.
• recession of the interproximal papilla and the
collapse of the buccal bone

179. Tooth isextracted,
Lossof support to thepapilla
slumping of thepapillary tissuesimmediately
Within 30-60 minutesthat papillawill haveslumped to
thepoint of no return.

180. •Theworst thing that can happen, when patient biteon the
gauzeimmediately after extraction, forcing thepapilla
down into thesocket site.

181. • Meticulous care should be given during surgery on
interproximal crestal bone.
• Damage the buccal or lingual plate of bone or the
soft tissue is crucial to the formation of a natural
looking ovate pontic site.

182. • To preserve the papilla during the extraction procedure
fill the extraction site with the provisional pontic as
soon as possible.
By creating a preoperative temporary bridge for the
socket area with an ovate pontic design, the papillae
will be supported during the healing phase
postoperatively.

183. • Tooth is missing for some time, generally there will
be a loss of ridge support creating a deficiency or
depression in the ridge overlying the missing root.

184. There is no way to regenerate a papilla, however by
building up the ridge with soft tissue, and then sinking a
round diamond into the soft tissue buildup, a simulated
papilla can be created.

185. A small round depression in the gingival tissue along the
ridge is created, allowing the pontic to be embedded
within the "crater" so as to appear to be emerging from
the ridge as would be seen in a natural emergence
profile.

186. Preparation of ovatepontic sitewill createillusion of
papillaeinterproximally

187. • Oncetheridgeaugmentation and ovatepontic sitehas
been developed and supported during healing with a
temporary bridge, thefinal bridgecan befabricated.

188. Ovatepontic appearsto benaturally emerging from ridge.

189. • In clinical situations where there is a black hole,
carefully measure the crestal bone to contact height.
• Leave the case in provisional restorations for 3-8
months and allow the papilla to grow back before
finishing the case.
• Completing the case prematurely will not allow
enough time for the papilla to regrow and
overbuilding will be required to eliminate the black
hole

190. Robert, A. Lowe. Ovate Pontic design: Maximizing aesthetics function of fixed
partial bridges. Aesthetic dentistry 2012
A 30-year-old healthy female complained about the cross-bite
relationship of tooth 12.
The patient did not want to go through orthodontic treatment and
refused implants. She was looking for a quick way to correct the
appearance of her tooth.

191. • Alginate impressions were made to fabricate study
models.
• The study models were sent to the laboratory for
fabrication of the temporary bridge.
• A diagnostic wax-up was made. Pictures were taken.
Teeth 13 and 11 were prepared for bridge abutments
and Periapical radiographs taken.

192. A critical factor is a delicate/ atraumatic extraction of the
tooth for bone preservation. (do not break the labial
plate of bone).
Atraumatic extraction of tooth 12.
Socket site is intact

193. The hard and soft tissues heights were in acceptable
levels. Bone grafting and connective tissue build-up was
unnecessary.
Temporary bridge resin was added to the underside of the
pontic, and reseated so that the resin flows into the
socket.

194. • The provisional pontic was constructed so that the
“egg” portion is submerged into the extraction site
about 2 to 3 mm .

195. Thetemporary bridgecemented in placeafter extraction and
sitepreparation.

196. • The patient was instructed to return in 48 hours for
removal of the temporary and evaluation of the
extraction socket for proper healing.
• After evaluation the temporary was re-cemented.

197. • After two weeks the socket was revaluated and the
gingival contour was sculpted with electrosurgery.

198. • A series of temporary bridges was necessary to
manipulate the soft tissues to recreate ovate pontic
receptor sites and natural-looking interdental papillae.
• After six weeks a slight inflammatory reaction was
observed in the soft tissues.

199. With each new temporary bridge, the aesthetics was
improved and the soft tissues compressed to help
form the papillae.
The tissue has adapted
to the temporary ovate
pontic.

200. Maturation of thepontic site
• Approximately four months after extraction and four
provisional bridges later the soft tissues had neared
maturation.
• A further increase in the buccal contraction was
seen, giving a significant increase in the tooth length
while the papillae closed the interproximal spaces
almost completely.

201. Once the final work is in place, the gingival
architecture was seen to be preserved and harmony
was satisfactory

202. Final impression and cementation
• Thefinal impression may betaken threeto four monthsafter
extraction, dueto thevariability in thehealing processfor each
patient.
• In thiscasethefinal impression for thefinal restoration wastaken
four monthsafter theextraction.

203. The all-ceramic restorations are shown bounded in
place. The gingival architecture, although more apical
in position, appeared to be preserved and demonstrated
satisfactory harmony.

204. • Thepatient wasinstructed to clean thisspecific areawith super
floss, to prevent any possibleinflammatory reaction.
• Also, theuseof awaterpik system using low pressure, aiming
thewater stream at theteeth at a90-degreeangle, not at thegum
tissue, wasadvocated.
• Theconvex shapeof thepontic allowsproper cleansing of the
edentulousarea.

205. Pre-treatment.
Post-treatment.

206. REVIEW OF LITERATURE

207. Artificial crown contours and gingival health
J Prosthet Dent 12:1146, 1962.
This article presents a rationale for not producing overcontoured
crowns because it causes and does not prevent gingival
inflammation..
Conclusions: The rationale of muscular molding and cleansing
rather than that of food impaction, more adequately explains
clinical phenomena and is a more accurate guide for the
construction of gingivally tolerated crowns.

208. • Burch, J.G Ten rules for developing crown contours in restorations.
DCNA 1971;15:611-618
• Purpose: To discuss the relationship between crown
contours, and the occlusal surface and cervical portion of
individual teeth.
The ten rules for developing contours are:
• 1)Faciolingual crown dimensions- no more than 1mm larger
than the faciolingual width at the CEJ. Possible exception:
mandibular molars and second premolars.
• 2)Facial contours- all facial contour crests are in the gingival
third, and should not bulge more than one-half mm beyond
CEJ

209. • 3)Lingual contours- greatest convexity at gingival 1/3 except
mandibular molars and sometimes mandibular second
premolar, where greatest convexity is found in the middle 1/3
of crown.
• 4)Proximal contact points- in the occlusal 1/3 of crown.
Maxillary molars may be at the level of the junction of
occlusal and middle thirds. Proximal contact points are
buccal to the central fossa line, except for maxillary molars
which are in the middle 1/3.

210. • 5)Proximal surfaces- between the marginal ridge and the
CEJ, the proximal surface is flat or slightly concave
buccolingually as well as occlusocervically.
• 6)Axial transitional line angles- straight between the
proximal contact point and the CEJ, with the exception of the
lingual line angles of maxillary molars, where there may be a
slight convexity.

211. • 7)Marginal ridges- should be the same height for adjacent
teeth. The facial ½ of any tooth is wider than the lingual.
Lingual embrasures are always larger than buccal embrasures
when viewed occlusally.
• 8)Crown margin- should be supragingivally except due to
esthetics, crown length to gain adequate retention, root caries,
root sensitivity, existing restorations.
• 9)Thickness of restoration subgingivally- inadequate contour
may not provide for adequate support for the gingival unit.
• 10)Crown margin/Bone relationship- do not encroach on the
biologic width.

212. • Physiologic design criteria for fixed dental
restorations. DCNA Vol 15, 3:543-568, 1971.
• Purpose: To explore the contours of axial tooth surfaces in
relationship to their environment so that they may function
physiologically.
As it is the function of the occlusal form to generate the least
amount of stress in the supporting tissues, it is the function of
the axial form of teeth to afford protection and stimulation to
the investing tissues or, more specifically, the marginal
periodontium.

213. Axial crown contours. J Prosthet Dent 25:642, 1971.
• The relationship between axial tooth contours and the surrounding
marginal gingiva was studied on six dogs and observed over 9 weeks.
• Procedures producing undercontours and overcontours, on buccal and
lingual crown surfaces, were performed. Clinical and microscopic
observations were made with respect to the marginal gingiva and the
crevicular areas: Undercontouring of axial surfaces did not produce any
significant changes in gingival health. Overcontouring produced
inflammatory and hyperplastic changes in the marginal gingiva. These
changes were seen clinically and microscopically at 4 weeks.

214. Facial and lingual contours of artificial complete crown restorations
and their effect on the gingiva. J Prosthet Dent 29:61, 1973.
• Purpose: to evaluate the purpose of the cervical bulge found in teeth and its effect on
protecting the gingiva from the traumatic effects of mastication.
• authors opinion, this cervical bulge overprotects the microbial plaque, and this can be
clinically demonstrated by utilizing disclosing solution.
• He states that to promote accessability of oral hygiene, final fixed restorations should
not follow the original anatomic crown but should recreate the normal contours of the
root portion.
• By flattening the facial and lingual contours, this would reduce unnecessary bulges,
and facilitate cleansability to the gingival third of fluted and furcation areas of teeth.
• This is especially true in teeth that have undergone periodontal therapy.

215. The interproximal embrasure. DCNA 15:641, 1971.
• Purpose: Identify problems related to the interproximal embrasure and
space during treatment procedures.
• Adequate tooth reduction and a proper provisional is the most
predictable way to establish a healthy embrasure zone. An over-
contoured restoration due to inadequate reduction will create an
inflammatory response of the periodontium and the resultant change in
the quality of the embrasure tissues.
• The interdental space must be kept free of bacterial plaque and
restorative materials to create an environment that will retain a state of
periodontal health

216. Excessive crown contours facilitate endemic plaque niches. J Prosthet Dent 35:424, 1976.
• Purpose: To study the facial – lingual width and the plaque indices of crowned teeth
and to compare the data to that for unrestored contralateral teeth.
• Materials and Methods: 25 cast metal crowns and PFM’s were evaluated.
• Measurements of the facial – lingual width at the height of contour were made on
the sample teeth as well as the contralateral tooth. Assessments of soft deposits
were made according to the plaque index system proposed by Silness and Loe.
• Results: A significant difference in the plaque accumulation was found in the
samples. More plaque was found on the teeth with restorations than with out. The
restorations were wider than the contralateral control teeth.
Conclusion: The creation of restorations with facial – lingual width greater than natural
tooth convexities must be considered another parameter to promote plaque.

217. The role of coronal contour in gingival health. J Prosthet Dent 37:280, 1977
• Purpose: To evaluate the role of coronal contour in gingival health.
• Conclusion: Total clinical crown contour is related to gingival health.
• Undercontour is better than overcontour where clinical judgement is vague.
• The facial and lingual surface contours should have gradual curvatures in all
directions to facilitate the rubbing and cleaning function of the lips, cheeks, and
tongue.
• The interproximal contour of the adjacent teeth, contact areas, and the teeth in
relation to the papilla must provide easy access for the patient to perform oral
hygiene.
• The subgingival convexity of a tooth or a restoration should extend facially or
lingually no more than ½ of the thickness of the gingiva. This protects the gingival
crevice and promotes knifelike free gingival margin, important in plaque control.

218. The Interdental Space. DCNA 24: 169, 1980
• The interdental area is the primary site of dental disease, both periodontal
disease and caries. Both diseases are microbial in origin and result from growth
and accumulation in the interdental area.
• Interproximal contours should minimize plaque retention areas optimize ease
in cleansing.
• A common error is to make the contact area too wide which leads to lack of
space for an occlusal embrasure and adequate marginal ridge.

219. • Current controversies in axial contour design. J Prosthet Dent
44:536, 1980.
Purpose: A review of theories of axial contour design.
• Food Deflection Theory:
• WHEELER- Proposed that convexities should be created in the cervical third of
artificial crowns and these convexities were deflect food away from the free
gingiva.
• MORRIS- Noted that the position of the gingival margin in part is determined
by the lingual or buccal tooth surface prominence. He placed an emphasis on
accessibility and oral hygiene measurement.
• HERLANDS et al- Questioned the rationale of the food deflecting contour
concept. He found that these crowns were overcontoured causing gingival
inflammation as well as the following:

220. • Papillae Impaction mechanism requires certain physical conditions,
substances being impacted must be fairly firm, there must be a
propelling force directing it towards an easily accessible area.
• Maximum bulge in a natural crown contour is 0.5 mm, this is considered
as inadequate protection against food impaction.
• Complete lack of contour is often observed when a tooth prepared for
full coverage is left uncovered for an extended period of time, but the
surrounding gingiva is usually healthy.

221. • MUSCLE ACTION THEORY
• HERLANDS et al and MORRIS- Introduced the theory. they used the
rationale of muscle molding and cleansing, rather than food impaction,
to explain the observable clinical phenomena found around natural and
artificial crowns. the theory promotes constant cleansing and molding
action by the muscles of the cheeks, lips and tongue.
• PEREL- Studies revealed:
• Undercontouring of axial surfaces did not produce any significant
changes in healthy gingiva.
• Overcontouring of axial surfaces produced inflammation and
hyperplastic changes in the marginal gingiva.

222. • YUODELIS et al- Questioned the food defection theory. They stated that
microbial plaque is the primary etiological factor in both caries and
periodontal disease.
• There is little in our modern diets that could injure the free gingival
margin.
• Propreceptive response usually provides adequate protection for the
free gingiva during mastication.
• The potential impact of food as the crushed bolus passes over the axial
contoue of the teeth is usually dissipated by the time the food reaches
the gingiva, since it tis directed by the cheeks, lips and tongue into a
position of deglutition.
• Most human dentition have little clinical bulge and show no deleterious
effect on mastication.

223. • PLAQUE RETENTION THEORY
• Axial conour design is based on the muscle-action theory.
• Crown contour should not harbor any plaque traps and promote self-
cleaning.
• ANATOMIC THEORY
• Anatomic or biologic concept of tooth contour, a contour which
simulated natural, healthy and self prtecting teeth.
• the facial and lingual convexities form the height of contour of tooth
crowns, which are located at the gingival third of each tooth and are
approximately 0.5 mm wider than the adjoining CEJ. (Exception- lingual
of mandibular molars and second premolars.)

224. • MARGIN PLACEMENT
• WAGMAN- Subgingival contour should be made convex facially and
lingually. Proper contour to maintain "knife-like" shape of the free
gingival margin. The degree of these convexities should not exceed 1/2
of the thickness of the gingiva at the height of the attachment.
• ROSS- If the subgingival contour is made flat and does not sopport the
gingiva, the free marginal gingiva will tend to form a "roll" around the
tooth. A margin placed coronal to the CEJ, the subgingival contour
should be made convex. Below the CEJ, should be made flat
• SPUROW AND LYTLE- Interproximal embrasure as a yardstick of
periodontal health in a patient with virgin teeth. Emphasized the
importance of creating proper embrasure space for the health of the
interdental

225. Faciolingual width before and after tooth restoration: A
comparative study. J Prosthet Dent 46:153, 1981.
• Purpose: To compare the data between the facial-lingual width of restored teeth
and the same unrestored teeth.
.
• study suggests that increases in the buccolingual dimension of approximately 0.7
to 1.0 mm may be accepted clinically by the surrounding tissues.
The results of this study indicate that measurements of the natural teeth, dies, and
provisional restorations can provide the dentist and the laboratory a method to
control the buccolingual width of the final restoration

226. Crown contours and gingival response. J Prosthet Dent 47:620-624, 1982.
• Purpose: Review of the current methods of evaluating gingival
response to restorative procedures and material, the design
theories of crown contours, and the guidelines for gingival
margin placement.
• Methods of evaluationg gingival response:
• -Subjective indices: color, texture, and bleeding on probing.
(prone to the dentists perception)

227. • Renggli and Regolati: compared plaque scores, those with
subgingival margins found to have more inflammation.
• Greatest increase in gingivitis, pocket depth, and loss of
attachment occurs with subgingival margins.
• Margins placed at the level of the free gingival margin result
in an insignificant increase in gingivitis.
• Closer a subgingival crown margin is placed to the base of
the gingival sulcus, the more severe the gingival
inflammation.

228. Restoration of the interdental space. Int J Perio and Rest Dent 3:30-45, 1983.
• Purpose: To understand the anatomy and biology of the
interdental area and how it influences the restorative
considerations in treatment.
Conclusions: By thoroughly planning the design of a restoration,
not only function and esthetics are restored but the health of
the interdental area is preserved.

229. Gingival esthetics. J Prosthet Dent 64:1-12,1990
to achieve gingival health and esthetics in fixed prosthodontics.
Gingival contact should be avoided whenever possible through the use of
partial veneer crowns, supragingival margins, or with colorless metal
ceramic restorations with margins located at the gingival crest.
•When subgingival margins are required, attention must be paid to:
Achieving optimal preprosthetic gingival health.
Minimizing gingival trauma from rotary instruments during tooth
preparation.
•Careful use of gingival retraction cord.

230. • Sulcus inspection following impression making to remove any residual
impression material.
• Well fitting , properly contoured, and smooth provisional and definitive
restorations.
• Postplacement follow up and reinforcement of adequate oral hygiene

231. Combined therapy for teeth with furcation involvement used as
abutments for fixed restorations. Int J Prosthodont 3:470-476,1990.
• Purpose: To describe the preprosthodontic and prosthodontic procedures for
preparing molars with degree 3 furcation for use as abutments for a fixed
prosthesis.
followed 58 patients for 10-18 years, 67 teeth received root resection or root
separation, 6 failed from recurrent caries and 4 from periodontal disease.
• showed 93% success rate restored with metal ceramic fixed restorations.