DENTIN HYPERSENSITIVITY

THIS IS TEST

• DEFINITION

• ETIOLOGY

• THEORIES OF DENTIN HYPERSENSITIVITY

• CLINICAL FEATURES• DIOGNOSIS• TREATMENT

CONTENTS

THE INTERNATIONAL WORKSHOP ON DENTIN HYPERSENSITIVITY(1983) HAS PROPOSED THE FOLLOWING DEFINITION FOR THIS CONDITION:

“ IT IS CHARACTERISED BY SHORT,SHARP PAIN ARISING FROM EXPOSED DENTIN IN RESPONSE TO STIMULI TYPICALLY THERMAL,EVAPORATIVE,TACTILE,OSMOTIC OR CHEMICAL AND WHICH CANNOT BE ASCRIBED TO ANY OTHER FORM OF DENTAL DEFECT OR PATHOLOGY”

DEFINITION

ORAL ANATOMY AND DENTAL TISSUES

CEMENTAL LOSS• GINGIVAL RECESSION

• PERIODONTAL DISEASE

• ROOT PLANING

• PERODONTAL SURGERY

ETIOLOGY

ENAMEL LOSS• OCCLUSAL

WEAR

• TOOTH BRUSH ABRASION

• DIETARY EROSION

• ABFRACTION

• PARAFUNCTIONAL HABITS

GINGIVAL RECESSION

ABFRACTION TOOTH BRUSH ABRASION

ETIOLOGY

1.DIRECT INNERVATION THEORY2.ODONTOBLAST DEFORMATION

THEORY/TRANSDUCER THEORY

3.HYDRODYNAMIC THEORY

THEORIES OF DENTIN HYPERSENSITIVITY

• FIRST THEORY TO BE PUT FORWARD

• NERVE FIBERS PRESENT WITHIN DENTINAL TUBULES INTIATE IMPULSES WHEN THEY ARE INJURED AND CAUSES DENTINAL HYPERSENSITIVITY.

DIRECT INNERVATION THEORY

DIRECT INNERVATION THEORY

DISPUTES ABOUT THIS THEORY:• NERVE FIBERS ARE PRESENT ONLY IN

THE PREDENTIN AND INNER DENTINAL ZONES

• WHEN PAIN INDUCING SUBSTANCES LIKE POTTASIUM CHLORIDE,ACETYLCHOLINE ARE APPLIED TO EXPOSED DENTIN,THEY FAIL TO ELICIT PAINFUL RESPONSE.

ODONTOBLAST DEFORMATION THEORY

• ODONTOBLAST OR THEIR PROCESSES ARE DAMAGED WHEN EXTERNAL STIMULI ARE APPLIED TO EXPOSED DENTIN.

• THEY CONDUCT IMPULSES TO THE NERVES IN THE PREDENTIN AND UNDERLYING PULP AND THEN TO CNS.

• DISFAVOURED AS THE ODONTOBLASTIC PROCESSES EXTEND ONLY PARTLY THROUGH THE DENTIN AND NOT UPTO DEJ.

• ODONTOBLASTIC MEMBRANE POTENTIAL IS TOO LOW TO PERMIT TRANSDUCTION.

• THERE ARE NO DEMONSTRABLE NEUROTRANSMITTERS IN THE NEURAL TRANSMISSION OF THE PULP.

THE MOST WIDELY ACCEPTED MECHANISM OF ACTION OF DENTIN HYPERSENSITIVTY , THE HYDRODYNAMIC THEORY WHICH WAS PROPOSED BY GYSI IN 1900 AND VALIDATED BY BRANNSTROM IN 1996

HYDRODYNAMIC THEORY

WHENEVER DENTIN IS EXPOSED AND STIMULATED BY TACTILE,CHEMICAL,THERMAL OR OSMOTIC STIMULI THERE IS RAPID MOVEMENT OF FLUID THROUGH TUBULES.

THIS CAUSES:• DIRECT STIMULATION OF

LOW THRESHOLD A- DELTA NERVE FIBERS

• INDIRECT STIMULATION OF A-DELTA NERVE FIBERS IN PULP BY DISPLACING ODONTOBLASTIC CELL BODIES.

MECHANISM:

MECHANISM

DIAGNOSIS

COMPLETE HISTORY

CLINICAL EXAMINATION

RADIOGRAPHIC EXAMINATION

SIGNS AND SYMPTOMS

VISUAL ASSESMENT RULE OUT PERI APICAL LESION

INTENSITY PHYSICAL ASSESMENT

FREQUENCY AND DURATION

DEPTH OF PERIODONTAL POCKET DEPTH

DIETARY CHANGES PERCUSSION TESTING

RESPONSE TO COLD AIR

1. FRACTURED RESTORATIONS2. FRACTURED ENAMEL EXPOSING

DENTIN 3. DENTAL CARIES4. POST RESTORATION SENSITIVITY5. CRACKED TOOTH SYNDROME6. BLEACHING SENSITIVITY

DIFFERENTIAL DIAGNOSIS

1. DIET COUNSELLING REGARDING CONSUMPTION OF ACIDIC FRUITS AND BEVERAGES

2. CORRECTION OF BRUSHING TECHNIQUE

3. CARE DURING OPERATIVE PROCEDURES

4. CARE DURING PERIODONTAL PROCEDURES

PREVENTION

1. DESENSITISATION BY OCCLUDING DENTINAL TUBULES

A)FORMATION OF SMEAR LAYER OVER EXPOSED DENTIN

B)USE OF TOPICAL AGENTS TO OCCLUDE EXPOSED TUBULES

CALCIUM HYDROXIDE PASTE

CALCIUM PHOSPHATE PASTE

SILVER NITRATE

FLUORIDES

FLUORIDE IONTOPHRESIS

POTASSIUM NITRATE

VARNISHES

DENTIN ADHESIVES

MANAGEMENT

C)PLACEMENT OF RESTORATIONS

GLASS IONOMER CEMENTS

COMPOSITE RESINS

D)USE OF LASERS

CO2 LASER

Nd:YAG,Er:YAG LASER

He:Ne LASER

2. DESENSITIZING BY BLOCKING PULPAL SENSORY NERVES

A)POTASSIUM NITRATE TOOTHPASTE

MANAGEMENT

• IT INCREASES THE REMINERALISATION OF THE EXPOSED DENTIN THUS REDUCING DENTIN PERMIABILITY

• DISADVANTAGE:IT CAUSES TEMPORARY OCCLUSION OF TUBULES

CALCIUM HYDROXIDE

• IT REDUCES DENTIN HYPERSENSITIVITY BY BLOCKING TUBULES AND DENTIN PERMEABILITY IS REDUCED

• COMMERCIALLY AVAILABLE PRODUCT – GC TOOTH MOUSSE

• IT CONTAINS AMORPHOUS CALCIUM PHOSPHATE AND CAESIN PHOSPHOPEPTIDE

CALCIUM PHOSPHATE PASTE

• IT REDUSES FLUID MOVEMENT BY PRECIPITATING PROTEIN OR SILVER CHLORIDE WITHIN THE DENTINAL TUBULES

• IT IS NOT USED NOWADAYS AS IT STAINS DENTIN AND ALSO DAMAGES PULP AND GINGIVA

SILVER NITRATE

• The mode of action is linked to their ability to form mineralised deposits within the tubule lumen and on the surface of the exposed dentine that help prevent transmission of the applied stimulus.

STRONTIUM CHLORIDE

• AGENTS-SODIUM FLUORIDE,STANNOUS FLUORIDEOR ACIDULATED PHOSPHATE FLUORIDE.

• USED AS MOUTH RINSES,TOOTHPASTES OR TOPICAL APPLICATION ON EXPOSED DENTIN.

• ACTION IS BY FORMING FLUORAPATITE WITHIN TUBULES WHICH BLOCK FLUID MOVEMENT WITHIN DENTIN.

FLUORIDES

• IONTOPHORESIS- PROCEDURE IN WHICH IONS OF CHOSEN MEDICAMENT ARE DRIVEN INTO SPECIFIC TISSUES BY MEAHS OF ELECTRIC CURRENT.

• FLOURIDE IONTOPHORESIS TRANSFERS FLUORIDE IONS INTO DENTIN FOR DESENSITIZING IT.

• UNIT HAS

-POSITIVE ELECTRODE IS PLACED ON PATIENTS FACE OR ARM

-NEGETIVE ELECTRODE IS PLASTIC TIP PLACED AROUND THE TOOH• 2% SODIUM FLUORIDE IS APPLIED ON THE EXPOSED

DENTIN AND IS TRANSFERRED DEEP INTO THE DENTIN ON ACTIVATION OF THE UNIT.

• IT IS REPORTED TO PROVIDE LONG-TERM RELIEF FROM HYPERSENSITIVE DENTIN.

FLUORIDE IONTOPHORESIS

• SOLUTION IS APPLIED ON DENTIN• OXALATE IONS REACT WITH CALCIUM IONS

IN DENTINAL FLUID TO FORM INSOLUABLE CALCIUM OXALATE CRYSTALS THAT BLOCK TUBULES AND PREVENT FLUID MOVEMENT.

POTASSIUM OXALATE

VARNISHES

THEY ACT BY FORMING A BARRIER OVER EXPOSED DENTIN.

THIS REDUCES HYPERSENSITIVITY AS IT REDUCES DENTIN PERMEABILITY. THEY PROVIDE ONLY TEMPORARY RELIEF.

USE OF LASERS

THEY OCCLUDE THE DENTINAL TUBULES BY PRODUCING LOCAL CHANGES AROUND THE EXPOSED DENTIN

THEY ALSO PRODUCE CHANGES IN CENTRAL PULP NEURON.

MANAGEMENT

POTASSIUM ION MAY DEPOLARIZE THE NERVE AND PREVENT IT FROM

REPOLARIZING, THEREBY, PREVENTING IT FROM

SENDING PAIN SIGNALS TO THE BRAIN.

POTASSIUM IONS ARE THOUGHT TO DIFFUSE

ALONG DENTINAL TUBULES AND DECREASE

THE EXCITABILITY OF INTRADENTAL NERVES BY

ALTERING THEIR MEMBRANE POTENTIAL

REDUCING NERVE EXCITATION, AND THE

ASSOCIATED PAIN

POTASSIUM NITRATE

DENTIN HYPERSENSITIVITY “THE COMMON COLD OF DENTISTRY”