Class 5 Restorations Subgingival CORD Isolation

What is abrasion?

Cause: Mechanical wear (toothbrush habit)

Affects: Teeth in groups (often unilateral)

Treatment: Composite (hybrid or flowable)

What is abfraction?

Cause: Stress corrosion (occlusion related)

Affects: Single teeth (often upper premolars first)

Treatment: Composite (hybrid or flowable), Light-cured GIC

What is erosion?

Cause: Chemical erosion (gastric causes)

Affects: Teeth in groups (lingual upper/buccal lowers)

Treatment: Composite (hybrid or flowable)

What is the Basic Erosive Wear Examination (BEWE)?

A simple, quick index for screening a patient’s erosion status used to assess the level of erosion

How does the Basic Erosive Wear Examination (BEWE) work?

The mouth is divided into 6 distinct areas and uses the criteria for sextant scores from 0 to 3. THe surface with the highest score is recorded for each sextant. The scores are summed to obtain a cumulative score that is the basis for determining interventions.

What are some management challenges for ETW?

• Early diagnosis of erosive lesions

• Initiation of preventive strategies and behavioral changes

• Early intervention with minimally-invasive restorative procedures

What should early diagnosis include for the management of Erosive Wear Examination?

• Charting of erosive lesions

• Sensitive teeth

• Staining

• Making note of areas of exposed dentin

What are some preventive habits that reduce the risk of ETW?

• Staying hydrated

• Rinsing with water before brushing

• Brushing with fluoride toothpaste

• Not brushing for at least 1-2 hours after an acid challenge

What is the bottom line in the management of ETW?

• Early diagnosis

• Initiation of preventive measures

• Early intervention to avoid the need for extensive and invasive care

Scoring criteria

What is this caused by? What would you grade it?

Erosion; 3 on all sextants

Guidelines for management

What are the multi-factorial components of tooth surface lesions

• Stress (abfraction)

• Friction (wear)

• Biocorrosion (chemical, biochemical and electrochemical degradation)

What are some causes of stress (abfraction)?

1. Endogenous

   1. Parafunction

   2. Occlusion

   3. Deglutition

2. Exogenous

   1. Mastication

   2. Habits

   3. Occupations

   4. Dental appliances

3. Types of stress

   1. Static

   2. Fatigue (cyclic)

What are some causes of friction (wear)?

1. Endogenous (attrition)

   1. Parafunction

   2. Deglutition

2. Endogenous (abrasion)

   1. Mastication

   2. Action of tongue

3. Exogenous

   1. Dental hygiene

   2. Habits

   3. Occupations

   4. Dental appliances

4. Erosion (flow of liquids)

What are some causes of biocorrosion (chemical, biochemical and electrochemical degradation)?

1. Endogenous (acid)

   1. Plaque (caries)

   2. Gingival crevicular fluid

   3. Gastric HCl

2. Exogenous

   1. Diet

   2. Occupations

   3. Miscellaneous

3. Proteolysis

   1. Enzymatic lysis (caries)

   2. Proteases (pepsin and trypsin)

   3. Crevicular fluid

4. Electrochemical

   1. (Piezoelectric effect on dentin)

What are some examples of noninvasive therapeutic options?

1. Desensitizer

2. Fluoride varnish

When should you restore non-cervical carious lesions?

1. Active cavitated carious lesions associated with the lesions

2. Cervical margins subgingival precluding plaque control increasing caries, biocorrosion and periodontal disease risk

3. Extensive tooth structure loss, which compromises the integrity of the tooth

4. Defect is in close proximity to the pulp, or the pulp has been exposed

5. Persistent dentinal hypersensitivity in which non invasive therapeutic options have failed

6. Prosthetic abutment

7. Esthetic demands: by patient request

What are some techniques to use for cervical isolation: buccal retraction

Butterfly clamp

What does the B4 clamp do?

It’s like a half 212: The B4 clamp aids in isolation by retracting tissue without harming surrounding gingival tissue

Which clamps are used to provide access if Rubber Dam is used?

B4, 212

Retraction cords

Instruments for packing retraction cord

Cord packer, plastic

What do astringents/homeostatic agents do?

Cause a contraction-retraction of the tissues; the hemostatic agents constrict blood flow through coagulation

What are some common astringent/hemostatic compounds

• Ferric sulfate 15-20%: Viscostat

• Aluminum potassium sulfate

• Aluminum sulfate

• Aluminum chloride 20-25%

• Racemic epinephrine 4-8%

What are the clinical steps for cord isolation?

• Before preparation, or before restorative material placement

• Evaluate the health of the gingiva and the depth of the sulcus to select the proper cord (single or double)

• Soak the cord in astringent/hemostat (recommended), avoid excess of the solution

• Loop the cord around the tooth, depending on the preparation area. Adjust the length to cover M to D

• Repeat the process for a second cord if needed

• At the time of removal (using after finish or polish) the cord should be wetted with water so it won’t grab and tear the tissues when it is removed, creating more bleeding.

• Once the cord is removed, the retraction is maintained for about 30 seconds. Use this time for further subgingival finish if needed

Where is cord actually packed?

Sulcus

Make sure you are going into the sulcus; start packing from the distal