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