Gingival Recession and Dentine Hypersensitivity

Question 1

Define Gingival Recession?

Answer 1

Gingival recession is defined as an apical shift of the gingival margin, causing exposure of the root surface of a tooth. Location of the marginal tissue apical to the cemento - enamel junction with exposure of the root surface

Question 2

New classification scheme for periodontal and peri-implant diseases and conditions (2018):

Answer 2

Other Conditions Affecting the Periodontium-Mucogingival Deformities and Conditions-

Question 3

Mucogingival deformities and conditions around teeth

Answer 3

Gingival phenotype
Gingival / soft tissue recession
Lack of gingiva
Decreased vestibular depth
Aberrant frenum / muscle position
Gingival excess
Abnormal colour
Condition of the exposed root surface

Question 4

Prevalence:

Answer 4

Recession of 1mm or more in 58% of adults age 30+
Increased prevalence and extent with age
37.8% and extent of 8.6% of teeth in 30-39 year olds
90.4% and extent of 56.3% in 80-90 year olds

Question 5

Greater gingival recession:

Answer 5

Left side of jaw
Males V females
Afrocarribeans V white Caucasians

Question 6

Aetiology of recession:

Answer 6

Bone morphology- Crestal bone
Trauma 
Keratinised Tissue
Local Plaque Retention Factors
restorative dentistry
calculus and plaque
Malocclusion
High attachment of fraenum
Periodontal disease

Question 7

Bone morphology- Crestal bone

Answer 7

Tooth positioning in the arch can affect the bone morphology around a tooth, gingival recession comes with alveolar bone dehiscence, it is not clear whether this develops before gingival recession or in parallel

Question 8

Trauma

Answer 8

Foreign bodies: Lower lip piercing/ Finger nail picking

Toothbrushing: Hard toothbrush, frequency, frequency of changing brush, technique

Partial dentures: Poorly designed or maintained/ Oral hygiene

Chemical trauma: Topical cocaine

Question 9

Keratinised Tissue

Answer 9

It was believed that a certain apico-coronal width of keratinised tissue was required, No minimum width.
Thickness and texture of attached gingiva is important,
thin, fragile tissue pre-disposed to recession in presence of plaque-induced inflammation or trauma

Question 10

Local Plaque Retention Factors

Answer 10

High muscle attachment and frenal pull

Restorative dentistry:
subgingival margins increase plaque retention
more pronounced inflammation seen in thin gingiva
? Does increase in thickness decrease risk of recession

calculus/plaque: studies correlate the prevalence of generalised recession with high levels of batcerial deposits round the tooth

Question 11

Periodontal disease

Answer 11

pocket redcuing following successful NSPT, surgical trratment may also result in more gingiva; recession

Question 12

Clinical Outcome of gingival recession:

Answer 12

Dentine Hypersensitivity
Aesthetic concerns
Plaque retention and inflammtion
tooth abrasion
root caries

Question 13

Define dentine hypersensitivty:

Answer 13

Dentine hypersensitivity is characterised by short, sharp pain arising from exposed dentine in response to certain stimuli, which cannot be attributed to any other dental defect or disease

It may go on to manifest as a dull ache beyond the duration of the stimulus, possibly as an altered (irreversible) pulpal response

Question 14

Epidemiology of dentine hypersensitivity:

Answer 14

Peak incidence is 20-40 years
Gender bias to sensitivity, F>M
And at an earlier age
Could be due to better OH, F>M

Question 15

Distribution of dentine hypersensitivity

Answer 15

Most frequently the buccal/labial cervical areas of teeth
In order of most often affected teeth
First premolars
Canines
Incisors 
Second premolars
Molars
Correspond to areas of gingival recession 
Correspond to areas of thinning enamel
Correspond to areas of cementum loss

Question 16

Types of stumli :

Answer 16

Thermal- hot and cold
Osmotic (hypertonic solutions)
Sweet/ Spicy/ Acid
Micro-organisms and their metabolites can penetrate tubules (?)
Desiccation-Drying of lesions often stimulates pain
With evaporation of fluids, there may be a thermal element
Electrical -Galvanic reactionsElectric pulp testing
Tactil-Touching/Probing/Tooth brushing

Question 17

Mechanism of sensitivity conduction

Answer 17

Odontoblasts as receptors?
Inconclusive

Nerves in dentine?
Only seen in 1% of tubules in the cervical margin, however electrical current and cold stimulate nerves directly

Hydrodynamic mechanism?
Currently accepted hypothesis (Brännström, 1963)

Question 18

Brännström hydrodynamic hypothesis

Answer 18

Dentine hypersensitivity caused by the movement of dentinal tubule contents
Increased outward fluid flow causes a pressure change across the dentine
Distortion of A-delta fibre causes pain

Question 19

Brännström hydrodynamic hypothesis

Answer 19

Dentine hypersensitivity caused by the movement of dentinal tubule contents
Increased outward fluid flow causes a pressure change across the dentine
Distortion of A-delta fibre causes pain
May be another process involved
Fluid flow changes also result in an electrical discharge
This may be able to stimulate nerves electrically

Question 20

why does size matter?

Answer 20

Width of tubule
Rate of fluid flow depends on 4th power of the radius
So if a tubule is twice the width fluid flow is 16 times greater

Question 21

Sensitive dentine shows:

Answer 21

A disrupted smear layer
Many more dentinal tubules at the surface
Tubules not occluded by deposits
Tubule diameter wider

Question 22

Root sensitivity

Answer 22

Term proposed for dentine hypersensitivity from gingival recession due to periodontal disease and treatment
Potentially microorganisms invading root dentinal tubules. May be different aetiology

Question 23

Dentine Exposure

Answer 23

Resulting from loss of enamel
Removal of enamel by restorative procedures
Attrition (not in cervical buccal lesions)
Abrasion
Erosion
Combined erosion and abrasion

Question 24

The role of Toothbrushing

Answer 24

Tooth brushing alone has no significant effect on hard tissues
Plus toothpaste, has potential to abrade dentine considerably
Toothbrush design/bristles may contribute indirectly

Question 25

The role of toothpaste

Answer 25

Abrasive particles might remove the smear layer and open tubules
Detergents might help to remove the smear layer
Tubules could be occluded with particulate matter from the paste

Question 26

Erosion

Answer 26

Intrinsic or extrinsic source of acids
enamel and dentine loss and surface softening
 tooth surface loss by toothpaste abrasion if intra-oral environment acid

Question 27

what factors other then PH in progression of erosion?

Answer 27

pH of the acid is not the only factor in erosion
Type, chemical strength, temperature, exposure time are other variables
Think of fruits other than citrus, health supplements, mouthwashes, fruit teas, alcopops, wine etc.

Question 28

History, examination and diagnosis?

Answer 28

Record extent of recession (millers classification)
Descriptive
Index
Identify aetiological factors

Question 29

Classically, dentine hypersensitivity is:

Answer 29

Of a sharp nature, duration usually as long as stimulus

Main stimuli cold or evaporative

Question 30

Differential diagnosis for dentine hypersensitivity

Answer 30

Cracked tooth syndrome
Incorrect placement of dentine bonding agents
Fractured restorations
Pulpal response to caries and restorative treatment
Restoration left high in occlusion
Palatogingival groove
Chipped tooth 
Vital bleaching

Question 31

TReatment planning?

Answer 31

Pain management
Prevent progression
Periodontal screening and early treatment

Question 32

Managing hypersensitivity

Answer 32

Tubule occlusion

Blocking pulpal nerve response

Question 33

Tubule occlusion

Answer 33

promotes formation of new tissue eg: smear layer, intratubular dentine, tertiary dentine in response to stimulus or trauma
application of an artificial barrier e.g.: varnish, dentine bonding agents, composite resins, GIC and toothpastes

Question 34

Blocking pulpal nerve response

Answer 34

Potassium ions diffuse along tubules and raise extracellular K+ conc, reducing nerve excitability
Unproven in humans
Clinically unlikely that ions will diffuse into tubules against flow of dentinal fluid

Question 35

Ideal qualities of barrier materials

Answer 35

Retentive
Insoluble
Penetrate tubules
Form mechanical tags into tubules
Seal the end of tubules

Question 36

Managing hypersensitivity: home use products

Answer 36

Toothpastes, gels and mouthwashes
Contain potassium, strontium, oxalate and fluoride salts
Potassium nitrate: Cochrane review (2005) no clear evidence
Novamin: releases of calcium and phosphate ions from saliva to give a hydroxyapatite-like layer
Long term use needed (cumulative dosing for effect)

Question 37

The placebo effect

Answer 37

All products achieved a modest reduction in hypersensitivity
This was irrespective of presence of active ingredients
West et al (1997) showed a placebo effect of 40%

Question 38

Managing hypersensitivity: in-surgery products

Answer 38

Varnish eg. Duraphat (5% NaF), Clinpro (5% NaF & Tricalcium phosphate)
1-3 layers of adhesive resin bonding systems eg. Seal and Protect, Optibond Solo, Scotchbond 1 (+ etchant?)
Desensitising polishing paste (calcium carbonate and arginine)
Reinforced GIC where there is abrasion cavity progression
Watch for overhangs at the gingival margin

Question 39

Comparison of efficacy

Answer 39

Fluoride varnish
Reasonable efficacy but dissolution over time
Resins
Good if film thickness adequate. Products which do not require etching (Ide et al. 1998)
GIC
Good at occluding tubules where indicated for use

Question 40

Preventive Patient Advice

Answer 40

Oral hygiene advice
Change from damaging brushing techniques to:
Modified Bass technique
Roll technique
Electric toothbrushes
Smoking cessation
Traumatic habits
Reduce risk factors
Diet history
Limit acidic drinks, do not brush immediately after
Night-time splints if wear from bruxism