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Joint Restorative Orthodontic Treatment
The classic situations where combined orthodontic-restorative management may
be required include:
(i) Up-righting severely tilted molar teeth (refer to PD note)
(ii) Management of 'peg laterals' or other diminutive teeth. (refer to
hypodontia note)
(iii) Management of teeth that been traumatized before or during
orthodontic treatment (refer to The Orthodontic Implications of Traumatized
Upper IncisorTeeth note)
(iv) Periodontal patients (refer to PD note)
(v) Management of Cleft Lip and Palate patients (refer to CLP note)
(vi) Orthognathic patients May to be older or present with incomplete
dentitions and hence their treatment may require input from a Restorative
Dentist. Scenarios are too diverse to summarize but major or more minor
'finishing touches' should be discussed in the treatment planning stage to
ascertain the potential benefits. (refer to orthognathic surgery note)
(vii) Hypodontia. (refer to hypodontia note)
(viii) Impact of endodontically treated teeth
(ix) Role of orthodontic in prosthodontics treatment
(x) Tooth Surface Loss
(xi) Modification of tooth color
Impact of endodontically treated teeth
RCT: The aim of root canal treatment is shaping the canal system to produce a
gradual smooth taper that would allow easy access of antimicrobial irrigants to
clean and remove microorganisms and pulpal debris followed by filling and
obturating the canal with an insoluble filling material.
Indications to RCT:
Pulpal or periapical pathology.
Overdenture abutments.
Internal/ external resorption.
Pulp exposure is expected.
Perio-endo lesions, hemisection.
Pulpal sclerosis
Contraindications:
Inadequate access.
Contamination.
Unrestorable tooth.
Poor periodontal support and tooth mobility.
Root fracture.
RCT preparation techniques:
1. Stepback technique
2. Stepdown, crown down allowing the coronal aspect of the canal to be
widened and cleaned before the apical part, with the advantage of
Improving access of the irrigating solution to the apical region,
Reducing the risk of pushing pulp tissue debris and microorganisms into
the periradicular area
Therefore diminishing the incidence of post-operative pain.
3. The double-flare techniques
4. Hand instrumentation
5. Rotary instrumentation
The endodontic-orthodontic relationship
The effects of orthodontic tooth movement on the pulp
RCT needs during orthodontic treatment
Difficulty in performing RCT during orthodontic treatment
Orthodontic in assisting RCT
Root resorption of endodontically treated teeth caused by orthodontic
forces.
In details:
A. The effects of orthodontic tooth movement on the pulp
One of the iatrogenic effect is loss of the pulp vitality
B. RCT needs during orthodontic treatment
If RCT commenced during orthodontic treatment, it is suggested that the
canals be cleaned and dressed and filled with non-setting calcium hydroxide in
the interim, this is usually changed every 3 months as it is prone to leakage. The
tooth itself should be well sealed between visits to prevent coronal leakage and
the tooth filled conventionally with well-condensed gutta percha at the end of
treatment. Observation period, usually of a minimum of 6 months, is
recommended for signs of bony healing.
Intermediate filling is not recommended anymore except in apexification
cases (Attack 2008)
C. Difficulty in performing RCT during orthodontic treatment
Difficulty to diagnose from radiographs due to radiolucent changes at the
apex.
Brackets/bands may obscure decay radiographically/clinically.
The tooth movement may mask symptoms.
Metal brackets/bands affect pulp testing
Tooth isolation may be compromised
Working length determination may be hampered as resorption may
destroy the apical constriction and radiographically the periodontal space is
widened.
Canal obturation can be hampered by dentinal sclerosis.
D. Orthodontic in assisting RCT: Tooth extrusion using light forces (30-
50gm) may be indicated for fractured teeth with margins below the crestal bone
and deep carious margins. The prime objectives of extrusion being to provide a
sound tissue margin for the ultimate restoration also a sound biological width
for the patient to maintain.
E. Root resorption of endodontically treated teeth caused by
orthodontic forces.
Root filled teeth are less likely to resorb (Drysdale 1996)
Other said the opposite
Initial radiographs followed by radiographic monitoring 6 months after
the start of tooth movement. If signs of resorption are noted, a delay of 3
months should be instituted and endodontic advice should be sought.
Where resorption is severe, treatment goals should be re-evaluated and
patients and parents informed.
Role of orthodontic in prosthodontics treatment
Short-span bridges have a better overall prognosis than longer-span
bridges (orthodontics can help by reducing space)
Root filled abutments are less reliable than vital abutments (This may be
a factor when there is a choice of teeth which could be extracted as part of an
orthodontic treatment plan)
If the dynamic guidance is carried on the pontic, the bridge needs
abutments at both ends (Orthodontics may be able to help reduce a hostile
overbite, or create a canine protected occlusion, or levelling arches, simplifying
matters). However, if the dynamic guidance is not carried on the pontic, the
bridge may not need abutments at both ends, (but vertical forces in intercuspal
position may mean that support at both ends is preferable to prevent a 'tilting'
force on a single abutment)
Since fixed bridges with more than one abutment need the underlying
preparations to be parallel to one another, it is helpful if the teeth are reasonably
parallel to start with, to avoid the need for excessive removal of tooth tissue
(Orthodontics can help with uprighting teeth)
Enough tooth height needs to be available to retain a bridge once the
tooth is prepared (Orthodontics may be able to help by extruding/ intruding
teeth)
Tooth Surface Loss
Relevance
Tooth surface loss is important to the orthodontist in these ways:
Orthodontists often see TSL and should be able to recognize the condition, give
advice and consider a tertiary referral.
Orthodontists may be involved in treatment planning and treating of patients
with TSL
Complications of the TSL
1. Aesthetics
2. Mucosal irritation from worn or fractured teeth
3. Functional problems such as difficulty in biting into food.
4. Sensitivity
5. Loss of vertical dimension which make restorative treatment complicated
6. Loss of tooth substance which make restorative treatment complicated
Types of TSL
1. Erosion
2. Abrasion
3. Attrition
4. Demastication
5. Abfraction
In details
1. Erosion
Aetiology
Acids that have a pH below the critical pH 5.5 erode tooth structure as well as
reduced buffering capacity of the mouth. It can be classified into:
A. Exogenous (dietary)
B. Endogenous (regurgitation of stomach contents).
Feature
1. Smooth, polished appearance
2. Absence of staining
3. Absence of developmental ridges
4. Rounded teeth
5. Increased translucency due to thinning of enamel
6. Amalgam and composite restorations stand proud
7. Palatal erosion often leaves a small line of enamel at the gingival margin
probably a result of the buffering from gingival crevicular fluid
8. Eroded teeth are more susceptible to attrition and abrasion
2. Abrasion
Aetiology
Overzealous oral hygiene techniques.
Toothbrushing soon (within one hour) after the teeth have been softened by acid
insult
Use of an abrasive toothpaste
in orthodontics esp. when teeth contact ceramic brackets
Feature
Rounded or V-shaped groove
3. Attrition
Aetiology
Associated with parafunctional habits such as clenching and grinding
Features
1. Flat cusp tips or incisal edges (dentine and enamel wear at the same rate)
2. Localized facets on occlusal or palatal surfaces
3. Flat facets related to functional movements
4. Restorations show faceting as well as teeth
4. Demastication
This term has appeared in the literature and represents a combination of attrition
and abrasion where tooth-tooth contact may occur during chewing of fibrous
foods.
It can be defined as "the loss of tooth tissue by wear during the mastication of
food" and is influenced by the abrasiveness of individual food and chewing
patterns.
5. Abfraction
This can be defined as "the pathological loss of hard tissue caused by
biomechanical eccentric loading forces".
Non-centric loading leads to deformation and tooth flexure which disruptions
the enamel crystalline structure at the neck of a tooth that then break away.
Abfraction is a controversial issue but it is important to appreciate that not all
cervical lesions can be explained by acid erosion and toothbrush/dentifrice
abrasion and the mechanics has been substantiated by finite element analysis
modelling
Management (RCS Eng. Guidelines)
I. History
A. Establishing the Patient’s Complaints
B. Medical History
1. Gastric disorders such as gastro-oesophageal reflux, sphincter incompetence,
hiatus hernia,oesophagitis and increased gastric pressure and volume.
2. Repeated vomiting can result from disorders of psychosomatic, gastrointestinal
and metabolic processes or may be drug
3. Pregnancy as the increased pressure in the abdomen may predispose to
regurgitation
4. Eating disorders such as anorexia and bulimia,
5. Medications such as hydrochloric acid for achlorhydria,iron preparations or
chewable vitamin C. Other drugs may have a less direct role to play, for
example, diuretics and antidepressants cause xerostomia
C. Eating and drinking habits
1. Type of food and drinks like fizzy drink and spicy food
2. Frequency of consuming these foods
3. Habit of eating or drinking certain food or drinks. Eg.holding citrus fruits
against the teeth9 or swishing carbonated drinks in the mouth until the gas
escapes
D. Socioeconomic condition
1. Economic and social condition determine the education background as well as
the quality of food consumed
2. Industrial erosion was frequently described in people exposed to acidic fumes
but it is unlikely to be a factor today due to the more industrial legislation.
E. Hobbies and sporting activities
1. Erosion is more common in people who swim regularly in gas chlorinated pools
where the water is acidic.
2. Vigorous exercise will result in dehydration and damage will be compounded if
acidic .sports drinks are consumed after exercise,
F. Habits
1. Localized areas of tooth wear may be seen in hairdressers who hold clips
between their teeth
2. Musicians who play instruments with mouth-pieces that contact the teeth.
3. Pipe smoking pen chewing and nail biting
G. Alcohol and drugs
1. Alcohol intake given that binge drinking followed by vomiting may cause
substantial damage.
2. Use of drugs due to the low pH of the drug or dehydration it induces
H. OH measures
1. The patient tooth brushing technique should be assessed
2. Oral hygiene products used
II. EXAMINATION
1. An extra-oral examination
TMJ clicking (associated with attrition)
masseteric hypertrophy (associated with attrition)
Parotid enlargement (associated with bulimia).
2. Intra-oral examination
Features characteristic of the different wear processes mentioned above.
Location of tooth wear
a) Palatal erosion suggests an intrinsic aetiology
b) Labial erosion implicates extrinsic factors
c) Incisal edges and cusps are generally associated with attrition Asymmetric
lesions may be due to abrasion
intermaxillary occlusion and dynamic occlusion
a) lack of posterior support can predispose to anterior tooth wear
b) Interferences in lateral excursions should be identified as they may encourage
bruxism
3. Special investigations
Periapical radiographs
Measure salivary parameters
Initial study casts
clinical photographs
silicone index
III. TREATMENT
A. Prevention must remain the corner stone in the management of dental erosion.
B. Elimination of the aetiological factors: the first priority in treatment of all forms
of tooth substance loss should be to control the aetiological factors and prevent
further destruction of the already compromised tooth tissue
C. Patient advice and counselling including:
Modifying the diet
Changing eating habits and frequency of eating
Instruction in non-abrasive oral hygiene habits
Use of alkaline mouth rinses, such as bicarbonate of soda Neutral sodium
fluoride mouthwashes.
a mouthguard or splint may be provided for night wear however, if a
mouthguard is provided in the presence of a condition such as reflux because it
would hold the acid against the teeth for prolonged periods and so increase the
damage. This may be overcome by applying an alkali such as sodium
bicarbonate, magnesium hydroxide or milk of magnesia to the fitting surface of
the tray to neutralize any acids approaching the tooth surfaces
D. Restorative treatment:
Tooth substance loss generally proceeds slowly, so for most patients there is no
pressure to commence active restorative therapy (the exception to this would be
a young patient with rapid erosive tooth wear and sensitivity due to the loss of
tooth substance encroaching on the pulp, or decreasing dental aesthetics due to
chipping of incisal edges)
Definitive treatment categorized into:
A. Appearance satisfactory:
Counselling,
Resorting the tooth loss by CF or GIC
Restoration of edentulous spaces where appropriate by fixed or removable or
implant
Treatment for controlling bruxist or clenching habits,
Adjustment and elimination of any occlusal interferences
B. Appearance not satisfactory: no increase in occlusal face height required.
Patients in category 2 are managed as for category 1 plus the treatment of the
aesthetic problems by conventional restorative measures.
C. Appearance not satisfactory: increase in occlusal face height required:
(i) Sufficient space available; Patients in this category are managed as for category
2 plus prosthetic work
(ii) Insufficient space available. Space can be provided by:
1. Tooth preparation with the consequent removal of more tooth tissue
2. Changing the jaw relationship surgically.
3. Conventional orthodontic treatment using combinations of fixed and/or
removable appliances:
In cases of localised anterior tooth wear, interocclusal space can be created by
careful overbite reduction and in certain cases lower incisor retraction or upper
incisor proclination.
4. Fixed or removable bite platforms
Originally described by Dahl in 1970.
The Dahl appliance is a removable or cemented cobalt chrome appliance which
covers the palatal surfaces of the maxillary anterior teeth.
This allows contact of the mandibular anterior teeth with the appliance, holding
the posteriors out of occlusion.
This, in turn, promotes intrusion of the anterior teeth and eruption of the
posteriors, thus providing space anteriorly.
It has been shown in an implant-cephalometric study to result in intrusion of
the anterior teeth by an average of 1.05 mm, and extrusion or eruption of the
remaining teeth, averaging 1.47 mm after 6–14 months, without causing undue
incisor proclination or TMD problems.
Current Dahl 'appliances' Over a period of 3 - 9 months the ICP contact
re-establishes.
Briggs 1997
I. removable chrome bite plane
II. fixed bite plane (essentially Maryland/Resin-bonded bridge retainer
wings otherwise called metal palatal veneers)
III. porcelain palatal veneers
IV. direct composite veneers
V. definitive or temporary crowns.
Modification of tooth colour
Relevance
A. Before treatment, Discolouration of an individual tooth may signify non-
vitality, which may require attention prior to orthodontic movement
B. During treatment, in respect of bonding appliances to abnormal tooth surfaces,
or restorations
Previously bleached teeth do not seem to pose a major barrier to normal
appliance bonding.
Teeth, which have been orthodontically bonded and debonded, may respond
more slowly to bleaching than previously unbonded teeth
C. After treatment, in optimizing an aesthetic result
Value Hue and Chroma
There are a number of ways of classifying colour, but one way is by dividing it
into three basic components, value, hue and chroma.
Value is most easily explained by imagining that one is looking at a colour on a
black and white television set. Pure white will appear white, and will have the
highest value. Black will appear black and have the lowest value. All other
colours will appear as various shades of grey, with a continuous gradation
between white and black. The position of a colour on this greyscale determines
the value.
Hue can be explained by the colours of the rainbow, red, yellow, blue etc
Chroma relates to the amount of a certain pigment present, best explained by
imagining taking a pot of white paint, then adding a few drops of red paint to
produce a pink of certain chroma. If more red paint is added, the chroma will
alter, but the hue will remain red.
Classification
1. Genetically determined
Normal dentine/enamel shade (intrinsic)
Dentinogenesis imperfecta (intrinsic)
Amelogenesis imperfecta (intrinsic)
2. Acquired during tooth formation
Fluorosis (intrinsic)
Drug e.g. tetracycline (intrinsic)
Medical condition effects e.g. high levels of circulating bilirubin, porphyria
(intrinsic)
Trauma e.g. to deciduous predecessor, or due to birth (intrinsic)
3. Acquired after tooth formation
Trauma e.g. deposition of blood products, pulpal sclerosis (intrinsic)
Restorative materials, e.g. amalgam (intrinsic)
Caries (intrinsic)
Physiological reparative deposition of dentine and age-related darkening
(intrinsic)
Stains onto the surface of the tooth e.g. from foods and drinks, or due to the
action of chromogenic bacteria (extrinsic)
Iatrogenic due to poor aesthetic dentistry
Treatment RCSEng. Guidelines by Wellbury 2004
1. Prophylaxis
2. Whitening tooth paste
3. Microabrasion
A. Hydrochloric Acid / Pumice Microabrasion :
Using this technique a maximum of 100 μm. of enamel is removed.
Mix 18/% hydrochloric acid with pumice.
Continue rubbing up to a maximum of 10 x 5 second applications per tooth.
Apply fluoride drops to the teeth for 3 minutes.
B. Phosphoric Acid / Pumice Microabrasion
Phosphoric acid 35% to enamel surface for 30 secs, wash and dry.
Remove frosted enamel with tungsten carbide composite finishing bur,
4. Non-vital bleaching
5. Vital bleaching
Vital bleaching – Chairside
Vital bleaching - Nightguard
6. Composite restorations
Localised Composite Restorations
Composite Veneers
7. Porcelain veneers