CHAPTER 9: ADDITIONAL CONSERVATIVE ESTHETIC PROCEDURES PART I

conservative esthetic

considered the “art” of dentistry

bc it emphasizes creativity, imagination, and artistic expression, producing immediate esthetic improvements.

no local anesthesia needed because reshaping is restricted to enamel

Goldstein

stated that esthetic dentistry is the art of dentistry in its purest form

basic artistic elements in conservative esthetic dentistry

shape or form

surface texture

color & translucency

position & alignment

symmetry & proportionality

crown outline of incisor when viewed from the facial or lingual position

trapezoidal

surface texture of youthful teeth

rounded incisal angles

pronounced perikymata

varied reflective surfaces

developmental depressions

softened facial line angles

open incisal/facial embrasures

smile characteristics of older individuals with attrition

sharp incisal angles

closed incisal embrasures

more prominent (less rounded) incisal angles

surface texture of older teeth

smoother surfaces due to attrition & wear

less pronounced developmental anatomy

cosmetic contouring

opening embrasures

rounding incisal angles

reducing prominent line angles

—minor reshaping of enamel to produce a more youthful appearance

significant esthetic changes be achieved through:

full-coverage facial restorations like veneers

treating all anterior teeth (and sometimes 1st premolars) visible in the smile

features examined when restoring a single anterior tooth

prominences

embrasure form

other unique contours

developmental depressions

how light & shadow affect tooth esthetics

depressions — create shadows and appear less conspicuous

prominent contours — reflect more light and appear more noticeable

contouring used to make a tooth appear narrower

bring developmental depressions closer

move mesio-distofacial line angles closer together

contouring used to make a tooth appear wider

place line angles and developmental depressions farther apart

contour changes make a tooth appear shorter

emphasizing horizontal elements

shifting incisal height of contour gingivally

moving gingival height of contour incisally

contour changes make a tooth appear longer

emphasizing vertical elements

moving gingival and incisal heights of contour farther apart

illusionary techniques

useful in diastema closure by maintaining original line angle positions

using contouring to increased tooth width less noticeable

main esthetic challenge when restoring a single anterior tooth

achieving a high degree of realism to match the natural surrounding teeth

techniques that can control tooth proportions in diastema closures

enhancing vertical elements

deemphasizing horizontal features

—to balance the apparent dimensions

governs the overall esthetic appearance of a smile

symmetry and proportionality of the teeth

must be mirrored across the midline to ensure symmetric central incisors

mesial contours

incisal embrasures

gingival embrasures

golden proportion

geometric concept applied to dental esthetics for proportionality

the golden proportion in dental esthetics

each tooth, starting from the midline, is about 60% (exact ratio 0.618) of the apparent width of the tooth immediately mesial to it

width-to-length ratio of mx central incisors by Sterrett et al

0.85 in men

0.86 in women

average width-to-length ratios of MX lateral incisors by Sterrett et al

0.76 in men

0.79 in women

width-to-length ratios of mx central incisors by Magne et al

0.87 for worn incisors

0.78 for unworn incisors

ideal width-to-length ratio for mx incisors (central / lateral)

0.80 for central incisors

0.75 for lateral incisors

altered passive eruption

affect width-to-length ratios of central incisors

it can produce a square (1:1 ratio) appearance

corrected by crown lengthening to restore an ideal 0.80 ratio

narrow, elongated, or short-wide central incisors

are avoided bc they are the dominant focal point of the smile, and distorted proportions reduce esthetics

treatments in achieving proper esthetic proportions

orthodontics

periodontics

crown lengthening

—often essential for ideal esthetic results

surface texture

it affects how light reflects off teeth, influencing realism and natural appearance

translucency

the degree to which light penetrates into a tooth or restoration before being reflected outward

vital in anterior restorations bc it creates depth, vitality, and a natural blending with surrounding teeth

happens if a restoration lacks translucency:

• the restoration appears flat, opaque, and artificial

why surface texture and polishability must be balanced

over-texturing — can trap plaque

over-polishing — may eliminate natural anatomy

type of preparation when using veneers for rotated teeth

intraenamel preparation

—with greater reduction in the area of prominence

how mild linguoversion be conservatively corrected

by augmentation with full facial veneers

—direct composite or indirect composite / porcelain

must be maintained when restoring malposed teeth with veneers

physiologic gingival contours

proper emergence profile to avoid gingival irritation

excessively thick incisal edges

avoided in restorations bc they compromise function and esthetics

proper incisal contour ensures functional occlusion

limited lingual enamel reduction

appropriate in malposed teeth treatment 

if occlusion allows, to reduce faciolingual dimension of the incisal portion—without altering areas in protrusive contact

determines the character and individuality of teeth

surface texture

existing characteristics

restorations w/o surface characterizations

rarely indicated bc they look unnatural and fail to blend with surrounding teeth

how natural tooth surfaces reflect light

they break up light and reflect it in multiple directions

color

artistic element considered the most complex and least understood

value

often the basis of some modern shade guide

thick enamel → lighter teeth

how enamel thickness affect tooth color in young individuals

aging-related changes affecting tooth color

cervical areas darken due to abrasion

enamel wear exposes dentin → teeth look darker

incisal edges darken from thinning enamel or attrition

most accurate method for shade selection

apply and cure a small amount of the restorative material directly on the tooth before isolation

metamerism

describes how different light sources produce different color perceptions

causes of color fatigue in shade selection

extended viewing of a tooth site reduces sensitivity to yellow-orange shades

how light normally interact with natural teeth

light penetrates through enamel into dentin before reflecting outward, giving teeth esthetic vitality

the restoration loses esthetic vitality and looks less natural when light penetration is shallow

opaque resin media

reduce esthetic vitality

they mask stains but block light penetration

color modifiers (tints)

used to create illusions of translucency

reduce brightness of stains, or add characterizations

apply violet (the complementary color of yellow)

how yellow intrinsic stains toned down with color modifiers to reduce intensity

other color modifiers besides translucency simulation

crack lines

surface spots

maverick colors

Dawson

emphasized the link between esthetics and function in dentistry

stated that “the better the esthetics, the better the function is likely to be and vice versa.”

to remove excess material and avoid irritation

why finishing gingival areas important

must be avoided in restoration emergence profiles

impingement on gingival tissue

emergence angles must be physiologic

conservative alteration of contour & contact

closing diastemas

correcting embrasures

reshaping natural teeth

attrition

causes of closed incisal embrasures & angular incisal edges

common causes of fractured or worn incisal edges

accidents

attrition

poor dental habits (e.g., biting fingernails, holding objects with teeth)

tools that visualize the esthetic improvement before reshaping

photographs

study models

line drawings

esthetic imaging devices

used for cosmetic reshaping and polishing of enamel

diamond instruments

abrasive discs / points

protrusive function

occlusal consideration that must be checked before incisal reshaping to avoid eliminating essential occlusal contact

less likely to chip or fracture

advantage of rounded incisal edges over sharp edges

esthetic problem with anterior embrasures

they can appear too open due to tooth shape or position in the arch

result when permanent lateral incisors are congenitally missing

canines or posterior teeth drift mesially

orthodontic closure leaves embrasures too open

—canines can be modified to resemble lateral incisors by reshaping their facial surface and cusp angle

composite resin

material is commonly added to correct open embrasures

composite mockup

temporarily adding unetched / unbonded composite to fill the embrasure to simulate the final result for the patient

aids in helping patients understand embrasure correction

line drawings

esthetic imaging

composite mockups

photographs of similar case

used to prepare overly convex enamel or roughen the surface before bonding

coarse, flame-shaped diamond

abrasive strips with a wedge

how to protect the adjacent tooth during etching

by inserting a polyester strip or teflon tape

bonding sequence for embrasure correction with composite

roughen enamel → place protective strip → acid etch → rinse/dry → position contoured strip → insert composite → polymerize

common etiologies of diastema

heredity

tongue thrusting

periodontal disease

supernumerary teeth

posterior bite collapse

congenitally missing, undersized, or malformed teeth

interarch tooth size discrepancy / bolton discrepancy

prominent labial frenum with fibers preventing approximation of incisors

traditional treatment options for diastema closure

surgical

periodontal

orthodontic

prosthetic procedures

more practical & conservative method of diastema correction

composite augmentation of proximal surfaces via adhesive procedures

boley gauge or caliper

used to measure the diastema and tooth width

cotton rolls

preferred over rubber dam in diastema closure bc they allow better evaluation of restoration contour relative to gingival tissues

purpose of gingival retraction cord

retracts soft tissue

prevents fluid seepage

allows composite extension slightly below gingival crest for natural contour

coarse flame-shaped diamond bur

used to roughen proximal surfaces for retention

approximately 0.5mm beyond

how far enamel be etched beyond the prepared surface

purpose of polyester strip

extends below gingival crest

prevents bonding to adjacent teeth

acts as a matrix to shape the composite

why first restoration be slightly over-contoured

to allow finishing and shaping to ideal contour after polymerization

used for contouring-finishing in diastema closure

fine diamonds

abrasive discs

finishing strips

carbide finishing burs

to tight proximal contact when restoring the second tooth

by displacing the tooth distally with fingers while holding the matrix against the first restoration

main conservative treatment options for discolored teeth

bleaching

veneering

porcelain crowns

removal of surface stains

microabrasion / macroabrasion

classifications of tooth discolorations

extrinsic (external)

intrinsic (internal)

common causes of extrinsic discolorations in young patients

eating habits

gingival bleeding

poor oral hygiene

existing restorations

plaque accumulation

chromogenic microorganisms

remnants of Nasmyth membrane

stains appear in older patients

brown

black

gray stains near gingival margins

lifestyle factors contribute to extrinsic stains

coffee / tea

tobacco use

chromogenic foods / medications

betel nut juice

a cultural example of intentional tooth staining

women traditionally stained teeth as a sign of beauty in Southeast Asia

teeth were pre-treated with weak acids (e.g., citrus juice) to demineralize enamel before applying betel nut juice

oral prophylaxis (cleaning)

routine treatment removes most surface stains

this alone cannot correct discoloration in a superficial stains on tooth-colored restorations or in decalcified enamel areas 

conservative treatments for intrinsic discolorations

veneers

bleaching

microabrasion

macroabrasion

intrinsic discoloration

more complex to treat than extrinsic discoloration

bc it is within enamel or dentin, and may involve deeper structural defects

can occur in vital teeth during crown formation, often involving several teeth

can affect both vital and nonvital teeth, as well as endodontically treated teeth

hereditary & environmental causes of intrinsic discoloration

high fevers

excessive fluoride

hereditary disorders

trauma during development

medications (e.g., tetracycline)

type of intrinsic discoloration as a result of tetracycline

generalized yellow-orange to dark blue-gray stains

depending on drug type, dose, and exposure time

minocycline (a tetracycline analogue)

antibiotic can cause gray discoloration of permanent teeth in adults with long-term use

an intrinsic stain results from excessive fluoride exposure

fluorosis — generalized discoloration / white or brown mottling

developmental causes of localized intrinsic discoloration

trauma

hypoplasia

high fevers

enamel / dentin defects

hypocalcified white spots

white spots

often signs of remineralization

mild intrinsic discolorations with intact enamel may not need restorative treatment 

caused by poor oral hygiene decalcified post-eruption especially during orthodontic treatment

causes of intrinsic discolorations from restorations

caries

corroded pins

secondary caries

metallic restorations

leakage around restorations

causes of intrinsic discoloration of nonvital teeth

deep caries

delayed endodontic treatment

pulp degeneration products stain dentin after trauma

calcific metamorphosis

calcification of pulp chamber / canal after trauma

causes significant yellow discoloration, difficult to treat

tooth may appear dark but still vital, bleaching can help