TOOTH WEAR & RESTORATION OF ABRASION LESIONS DR HSU ZENN YEW

DDS (UKMal), DCLINDENT (Adel)

TERMINOLOGY

‘Tooth surface loss/ TSL’ or ‘tooth wear’:

refers to the loss of tooth tissue by a disease process other than dental caries/ trauma. (Eccles, 1982)

VS

‘Early Enamel Caries’:

Subsurface mineral loss beneath relatively intact surface zone.

Caries

Caries

Tooth wear

Subsurface mineral loss

www.doctorspiller.com

Ungar et.al (2008)

Bailey S & Liu W (2010)

“…the human dentition is basically “designed” on the premise that extensive wear will occur…” Kaifu et al

BDJ 2006

CAVEMAN DIET.. BEST WAY TO SLIM DOWN?..

Is Tooth Wear Physiological or Pathological?

Physiological TSL:

Wear & tear process

Increased wear in older patient

Pathological TSL: Teeth are so worn that they affect-

Function: diificulty in mastication, speech

Aesthetics : seriously affect the appearance

Longevity / survival of teeth : whether tooth will survive until end of life span

Comfort: Exposed dentine -> dentinal sensitivity or pulpal symptoms

CLASSIFICATION

TOOTH WEAR

EROSION ABRASION ATTRITION ?

ABFRACTIONS

D.W. Bartlett and P. Shah (2006)

EROSION

Defined as loss of dental hard tissue as a result of chemical process NOT involving bacteria

Clinical features:

melted appearance (dull appearance)

cupping or grooving on occlusal/incisal surfaces

edges of restorations appear to rise above the level of the adjacent tooth

Lussi 2006

EROSION

silky-glazed appearance of the tooth shallow concavities coronal from the cemento-enamel junction

rounding of the cusps and grooves No occlusal morphology present

Lussi et 2006

CAUSES OF EROSION

ACID ATTACK PROTECTIVE MECHANISM

Biological:

•Saliva: flow rate, composition, buffering capacity and stimulation capacity

•Acquired pellicle: composition, maturation and thickness

•Type of dental substrate (permanent and primary enamel, dentin) and composition (e.g. fluoride content as FHAP or CaF2-like particles)

•Dental anatomy and occlusion Chemical factors

• pH and buffering capacity of the product

• Type of acid (pKa values)

•Citric acid caused more erosion than phosphoric acid

Occupation:

•Workers chemical industry

•Wine tasters

•Swimmers exercising in water with low pH

•Athletes consuming frequently erosive sport drinks.

Behavioural:

•Healthier diet style: diet high in acidic citrus fruits, fruit juices, vegetables

•Unhealthy life style: consumption of designer drugs

•Alcoholic

•Excessive consumption of acidic foods and drinks: soft drinks, wine, vinegar

EXTRINSIC INTRINSIC

Medical:

Common causes for the migration of gastric juice through the lower and upper oesophageal sphincters are • Gastroesophageal reflux disease, hiatus hernia, chronic indigestion •Eating disorders: Anorexia and Bulimia, ruminification •Chronic alcoholism •Pregnancy

Pickards’ Manual, Lussi 2006

ABRASION Defined as ‘the pathological wearing away of dental hard tissue through

abnormal mechanical processes involving foreign objects or substances other than by opposing teeth’.

‘Three- body wear’

Clinical characteristics:

Commonly present buccally

Cervical region

Disc shaped

??V-shaped notch (a/w abfractions)

Pickards’ Manual, Lussi 2006 http://www.teethforbetterhealth.com Badel et. Al 2007

ABRASION

Causes:

Abnormal habits:

Chewing pencils, cigar pipe, thread biting

www.mymuseum.org.uk

ABRASION

Causes:

Toothbrushing/ Oral hygiene habits

Depends on relative dentine abrasivity (RDA) of the toothpaste.

International Standards Organisation (ISO) laboratory test. ISO stipulates that the RDA of toothpastes should not exceed 250

Whitening toothpaste containing alumina may have high abrasivity.

“Normal toothbrushing habits with toothpastes that conform with the ISO standard will, in a lifetime’s use, cause virtually no wear of enamel and clinically insignificant abrasion of dentine (a figure of 1 mm in around 100 years is often cited)”

Addy et al 2003

ABRASION

Causes:

Toothbrushing/ Oral hygiene techniques

Modified bass and roll technique vs horizontal/scrub technique

The effect of acid on enamel and dentine makes the tooth more susceptible to abrasion.

Recommendation : delay at least 1 hour after acidic meals

Addy et al 2003

ABFRACTION

Controversial

Defined as fracture of dental tooth structure caused by occlusal loads of functional and parafunctional force producing stress concentrations around the cervical margin of the crown.

Occlusal forces produce the flexion of the teeth both axially and paraaxially.

The destructive effect on teeth will be intensified by effects of erosion and abrasion

?V-notched at cervical area

Pickards’ Manual, Lussi 2006 http://www.teethforbetterhealth.com Badel et. Al 2007

ATTRITION

Attrition is defined as the loss of enamel, dentin, or restoration by tooth-to-tooth contact (Pindborg, 1970).

Physical wear as a result of the action of antagonistic teeth with no foreign substances intervening (two body wear)

It occurs primarily on occlusal surfaces of teeth or interproximal areas.

Clinical features:

Flat surfaces

Glossy areas with distinct margins

Correspond to antagonistic teeth

Pickards’ Manual, Lussi 2006, Badel et al 2007

ATTRITION

Mechanical loss or in combination with erosion

Affects non-contacting occlusal

Causes:

1. ? Diet: Abrasive diet (e.g vegetarian)

? contemporary diet

Pickards’ Manual, Lussi 2006, Badel et al 2007

ATTRITION

Causes:

2. Bruxism: diurnal and nocturnal parafunctional activity that includes clenching, bracing, gnashing, and grinding of teeth

But..

“Tooth wear is a poor indicator of bruxism..” -> Patients with tooth wear may not have bruxism

“Even if a patient is suspected of having bruxism, dental erosion is more likely the cause of tooth-tissue loss than attrition.”

Khan et al 1998

Pickards’ Manual, Lussi 2006, Badel et al 2007

ATTRITION

Causes:

3. Iatrogenic:

If the restorative material has a greater abrasiveness than enamel (for example, ceramic bridges and crowns and ceramic pontics in dentures), only the antagonist teeth surfaces will undergo tooth wear

Materials which are softer than tooth enamel (composite fillings, acrylic pontics in dentures, acrylic facets and occlusal planes in crowns and bridges, etc.) will wear out to a greater extent whereas enamel of antagonist teeth will remain intact.

Pickards’ Manual, Lussi 2006, Badel et al 2007

CLASSIFICATION

TOOTH WEAR

EROSION/ COROSSION

Chemical wear

ATTRITION

Physical wear: tooth-tooth

surfaces

ABRASION

Physical wear

? ABFRACTIONS

Flexion of tooth

Lussi 2006, D.W. Bartlett and P. Shah (2006)

“It is challenging to distinguish between the influences of erosion, attrition or abrasion during a clinical examination.” “..They may occur simultaneously with sometimes similar shape.”

MANAGEMENT

DIAGNOSIS

PREVENTION

STABILIZATION

RESTORATION/ REHABILITATION

REVIEW / MONITORING

PREVENTION

TOOTH WEAR PROTECTIVE MECHANISM

PROFESSIONAL INTERVENTION

•Night guard for bruxism

•Stimulate saliva flow with chewing gum or lozenges.

•Remineralization:-

•Topical fluoride (NaF, APF, SnF)

•ToothMousse® (CPP-ACP/ Casein Phosphopeptide -amorphous calcium phosphate

MEDICAL REFERRAL

Refer patients or advise them to seek appropriate medical attention gastroenterologist and/or a psychologist) when intrinsic causes of erosion are involved.

Pickards’ Manual, Lussi 2006 OHI

•Avoid tooth brushing immediately after an erosive challenge (vomiting, acidic diet). •Use a fluoride containing mouth rinse, a sodium bicarbonate (baking soda) solution, milk or food such as cheese or sugar-free yoghurt. If none of the above are possible, rinse with water. •Use a soft toothbrush and low abrasion fluoride containing toothpaste. & proper technique

OHE

• Reduce acid exposure by reducing the frequency, and contact time of acids (main meals only). Do not hold or swish acidic drinks in your mouth. Avoid sippingt hese drinks.

STABILIZATION

Monitor preventions strategies: monitor progression of tooth wear

OHE reinforcement.

Address symptoms and prevent further damage

Eg: dentine hypersensitivity: bonding agent / topical desensitizing agent may be placed temporarily or semi-permanently over exposed dentine.

Composites may be placed temporarily or semi-permanently over exposed areas

Endodontic treatment: irreversible pulpitis necrotic pulp or periapical pathology

RESTORATION

ONLY NECESSARY IF TOOTH WEAR IS PATHOLOGICAL

Patient complaint/ presented with:

Function deficit: diificulty in mastication, speech

Aesthetics problems: seriously affect the appearance

Longevity: threat to the strength of tooth

Cause discomfort/ pain/ sensitivity

Function Aesthetic Longevity Comfort

ABRASION LESIONS

a.k.a. non carious cervical lesions (NCCL), non carious Class 5 lesions

NOT ALL ABRASION LESIONS REQUIRE RESTORATIONS:

When do we restore?

RESTORATION OF ABRASION LESIONS

ACCESS & ISOLATION

Difficult access in buccal surface of upper posterior, lingual of lower molar

Difficult access in subgingival lesion :

Non surgical retraction: retraction cords, rubber dam is sometimes useful to retract tissue

Surgical retraction: conventional, electrocautery, laser surgery

Simultaneus: combined surgical-restorative or

Two-step: surgery-> 4-6 weeks for gingival healing and maturation -> restoration

Pickard’s Manual www.cdeworld.com

RESTORATION OF ABRASION LESIONS

SELECTION OF DENTAL MATERIALS

RESTORATIVE MATERIALS

Non esthetic materials Amalgam Gold foil (not widely used) Gold inlay

Esthetic Materials Resin composite Flowable resin composite Resin composite with dentine bonding systems Resin composite with glass ionomer liner Glass ionomer Resin Modified Glass Ionomer Compomer Porcelain Inlay (not widely used)

RESTORATIVE MATERIALS

Adhesion to enamel

Adhesion to dentine

Esthetic Sensitivity to moisture

Amalgam Poor Requires removal of tooth structure for retention

Poor Requires removal of tooth structure for retention

Poor Good

Gold foil (not widely used)

Poor

Good

Gold inlay

Poor

Good

Flowable resin composite

Good Poor Excellent Poor Blood, gingival crevicular fluid, saliva affect success

Allow easier sculpting

Resin composite with dentine bonding systems

Good Poor High C-factor Esp in deep, subgingival cavity

Excellent

Glass ionomer Good Good Satisfactory Satisfactory F- release

Resin Modified Glass Ionomer

Good Good Good Satisfactory

Compomer Good Poor Good Poor Inferior to CR

Porcelain Inlay (not widely used)

Poor Poor Excellent Good Requires laboratory

Factors: Depth of cavity, remaining tooth structure (enamel/dentine) on margin, esthetic requirement, ability for moisture control,cost, operator preference

SANDWICH TECHNIQUE

Defined as resin composite with glass ionomer liner

‘Closed’(enamel margin)/ ‘Open’ (bonded margin) sandwich techniques

Combined benefits of GIC and composite

GIC is used to replace missing dentine

fluoride release ->Protect gingival margin against demineralization

Better adhesion to dentine through chemical bonding/ ion exchange mechanism ->reduce microleakage and increase retention

Composite is used to replace missing enamel

Esthetics (compare to opaque GIC)

Increased abrasion resistance

Good bonding to enamel

Missing dentin is replaced with either a resin-modified or high-viscosity glass ionomer.

Composite resin is used to replace enamel and seal the enamel margins surrounding the cavity

Enamel remaining in gingival margin

This modification of the closed sandwich untilized in cavities lacking enamel at the cervical margin.

A glass ionomer is used in lieu of composite resin to restore the cervical aspect of the proximal box, imparting optimal resistance to microleakage and secondary caries along dentin margins

Bonded base

Clinical trial: 96% survival after 5 years

Open sandwich: indicated for patients with good oral hygiene

GIC susceptible to surface degradation esp in acidic environment/ high caries risk

Fundamental Operative Dentistry Hewlett et al 2003

Further reading

Bailey S & Liu W. A comparative dental metrical and morphological analysis of a Middle Pleistocene hominin maxilla from Chaoxian (Chaohu), China. Hominin Morphological and Behavioral Variation in Eastern Asia and Australasia: Current Perspectives. 2010;211(1),p14–23

Ungar et.al (2008). Dental Microwear and Diet of the Plio-Pleistocene Hominin Paranthropus boisei. PLoS ONE, 3(4), e2044.

Laser dentistry and prehistoric teeth. British Dental Journal 201, 693 (2006)

Yousuke Kaifu, Kazutaka Kasai, Grant C. Townsend, Lindsay C. Richards. Tooth wear and the “design” of the human dentition: A perspective from evolutionary medicine. 2003; 122(37) p47–61

http://www.ucl.ac.uk/archaeology/research/directory/disease_hillson

Addy M, Hunter ML: Can toothbrushing damage your health? Effects on oral and dental tissues. Int Dent J 2003;53:177–186.

Badel et al. Clinical and Tribological View on Tooth Wear. Acta Stomatol Croat. 2007;41(4):355-365.

Hewlett et al . Glass Ionomers in Contemporary Restorative Dentistry -- A Clinical Update.JUNE 2003 JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION