Marginal intergity and periodontal considerations/certified fixed orthodontic courses by Indian dental academy

MARGINAL INTERGITY AND
PERIODONTAL
CONSIDERATIONS
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

CONTENTS
 Introduction
 Periodontium
Biological width
Evaluation of biological width
Evaluation of periodontal width
 Location of the margin
Supragingival
Subgingival
 Crown lengthenng procedures

 Periodontal health and restorative procedures
Various finish lines
Soft tissue management
Restorative materials
Functional effects
 Techniques to improve the fit of the cast restrotation
 Maintenance phase
 Summary and conclusion
 References
57.jpg

INTRODUCTION

PERIODONTIUM
GINGIVA
Its the part of the mucosa that covers the alveolar process
of the jaws and sorrounds the necks of the teeth.

PERIODONTAL LIGAMENT
o It’s the connective tissue that sorrounds the root and connects it to
the bone
o Its mainly made of collagen fibres - principle fibres
o Attachment complex – Supracrestal fibres
o - Junctional epithelium
o BIOLOGICAL WIDTH or the Subcrevicular attachment complex

BIOLOGICAL WIDTH
It’s the dimension of space that the healthy gingival tissues occupy
above the alveolar bone.
It refers to the combined connective tissue-epithelial attachment from
the crest of the alveolar bone to the base of the sulcus.

Violation of biological width:-

 Nevins and Sukrow in 1984 recommended that for the maintenance
of healthy periodontium, no restoration should violate the
attachment ,even though its not possible for a clinician to identify
the most coronal extent of the junctional epithelium.
 Wilson and majnard cautioned against extending restorations so far
subgingivally that the attachment complex is damaged.They stated
that “Some distance of unprepared tooth structure should remain
between the finished line and junctional epithelium and this distance
should be ideally 0.5mm.

 Eissman et al recommended that restorations not be
placed at or near the alveolar crest and there must be
2mm of root surface between the alveolar crest and the
restoration to provide for biological width.

Evaluation of the biological width
 Radiographs
 Probing
 Sounding of bone

Evaluation of the periodontal health:-
 Clinical examination
 Probing
 Intracrevicular fluid

Gingival index:-(Loe and Silness)
0 Normal gingiva
1 Mild inflamation
Slight change in colour and edema.No
bleeding on probing
2 Moderate inflammation
Redness and edema .Bleeding on probing
3 Severe inflamation
Marked redness,edema and
ulcerations.Spontaneous bleeding

The Supporting tissues should be in a state of
health prior to preparation of a tooth for any
restoration.

Location of restorative margins:-
 Supragingival
 Equigingival
 Subgingival

Supragingival margin:-
 Least traumatic to the soft tissues
 Margin placement…
 Clinical verification…
 Easily finished
 Impressions are easily made
 Most accessible for cleansing
 Restorations can be easily evaluated

Subgingival margins:-
 Clinical crown is short…
 Old restorations…
 Esthetic appearance
 Caries, abrasion or erosion…
 Root sensitivity

The healthy, stable gingival margin is the reference of
choice
Acc to Wilson and Maynard, the restorations are placed no
deeper than 0.5mm into the sulcus so that they can be
reached by the patients hygienic efforts

Disadvantages of subgingival margins
 Plaque retention…
 Margin placement…
 Mechanical irritation…
 Violation of biological width
 Soft tissue injury…

Criteria for subgingivl margin placement:-
 Emergence profile
 Margins are closed and properly finished
 Adequate band of attached gingiva
 Margin should not violate the biological width

Crown lengthening procedures:-
It’s a procedure similar to the apical repositioning of the flap with
concomitant ostectomy or osteoplasty.
Indications –
 Short clinical crown
 Restoration impinge on the biological width
 Hopless teeth
Crown lengthening procedure -
 Surgical methods
 Orthodontic method

Review of literature:supragingival/subgingival
Guy.M.Newcomb in 1974 conducted a study on “The relationship
between the location of subgingival crown margins and gingival
inflamation” and concluded that the nearer a subgingival crown
margin approaches the base of the gingival crevice, the more likely
its that severe inflammation will occur.
D.A.Orkin and D. bradshaw in 1987 conducted a study on the
“Relationship of the positions of crown margins to gingival health”
and showed that gingival tissues tend to bleed 2.42 times more
frequently with subgingival margins and have 2.65 times higher
chance of gingival recession

D.A.Felton in 1991 conducted a study on “Effects of in vivo
crown margin discrepancies on the periodontal health” in
his study he strongly supported the placement of
supragingival margins for artificial crowns and FPD’s.
William.G.Reeves in his review article concluded that more
supragingivally a restorative margin is placed,the less
chance that the margin will contribute to gingival
inflammation.

Periodontal health and restorative procedures:
 Tooth preparation
 Temporary restorations
 Functional effects of the reconstruction impinging on the
periodontium
Principles of tooth preparations:-
 Preservation of tooth structure
 Retentation and resistance form
 Structural durability
 Marginal integrity
 Preservation of the periodontium

Marginal integrity
 The restoration can survive in the biological environment …
 The configuration of the preparation finish lines dictates…
For evaluation following guidelines for margin design are described:
 Ease of preparation without overextension or unsupported enamel
 Ease of identification in the impression and on the die
 Sufficient bulk of the material
 Conservation of the tooth structure

Finish lines
The most important consideration in selecting a cervical margin design
is its ability to consistently and predictably provide excellent
marginal integrity.
 Knife edge
 Chamfer
 Shoulder
 Shoulder with bevel

Knife edge
 Conservation of the tooth structure
 Permits an acute margin of the metal
Disadvantages:
 The axial reduction may fade out
 Thin margin may be difficult to accurately wax and cast
 More susceptible to distortion
 Results in overcontouring
Indications:
 Lingual surface of mandibular posterior teeth
 The surfaces towards which tooth has tilted

Chamfer
 It provides distinct margin
 Adequate bulk to the restoration
 Easier to control
 Round end tapered fissure bur or torpedo bur
 Care needed to avoid unsupported lip of enamel
Indications:
 Cast metal restorations
 Lingual margin of the metal ceramic crowns

Shoulder
 Bulk of the restoration
 Wide ledge provides resistance to occlusal forces
 Provides space for healthy restorative contours
 Maximum esthetics
 It offers resistance against distortion during processing
Disadvantages:
 Requires destruction of more tooth structure
 The sharp 900
internal line angle…
Indications:
 All ceramic restorations
 Facial magins of metal-ceramic crowns

Radial shoulder:
Stress concentration is less in the tooth structure
Shoulder with bevel:
Used as a gingival finish line on the proximal box of inlays and onlays
Gingival esthetics is not critical…
Shoulder is already present…

Biological width violations are primarily a function
of margin placement and are independent of
margin design. – Donovan TE

Marginal intergity and periodontal considerations/certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Marginal intergity and periodontal considerations/certified fixed orthodontic courses by Indian dental academy

Similar to Marginal intergity and periodontal considerations/certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Marginal intergity and periodontal considerations/certified fixed orthodontic courses by Indian dental academy