endo sheet # 1

بسم الله الرحمن الرحيم
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Introduction to Endodontic Therapy

Endodontology means inside the tooth, the chamber inside the tooth that contains the nerve.

Endodontology: a branch of dental science which is concerned with the study of:

1- Form of dental pulp and periradicular region.
2-Function of dental pulp and periradicular region.
3-Health of dental pulp and periradicular region.
4-Injurie of dental pulp and periradicular region.
5- Disease of dental pulp and periradicular region.
6- Treatment.

Endodontology treatment: procedure designed to maintain the health of all or part of the pulp.

When the pulp is diseased or injured by micro-organisms, mechanical (trauma) or chemicals, the goal is to maintain and restore the periradicular tissue.

Periradicular tissue is the tissue that surrounds the tooth. It includes:

1. Periodontal ligament.
2. Alveolar bone.
3. Cementum.

The final goal of dental treatment is to allow the tooth to remain functional in the dental arch.

History
Chinese & Egyptians described caries & alveolar abscess.
( Puis).
They had the "worm theory" which was acceptable until the mid 18th century.

 To treat the cause of caries which was thought to be a certain worm, they used arsenic which is carcinogenic, mutagenic & a very harmful material.

Greek & Romans cauterize the pulp with a hot needle or boiling oil in order to devitalize the pulp to relieve the pain.
 At the end of the 1st century, it was realized that pain could be relieved by drilling into the pulp chamber to obtain drainage.

Goals of root canal therapy
1.Reduce pulpal pain.

2. Provide restoration for a dowel (da3ameh) crown which is inserted into the pulpal space & used to hold the crown restoration.

3. Bridge work.

 A misconception appears which states that any tooth that is prepared for crown restoration must be devitalized first.

 In 1884, the use of local anesthesia of 4% cocaine as a mandibular nerve blocker that supplies the lower teeth.

 In 1904, the 1st synthetic local anesthesia (BROCAIN) was produced.

 Introduction of special instruments to remove the pulpal tissue and to clean deposits from the canal.

 In 1895, discovery of radiograph (x-ray), 1st teeth radiography was taken Roentgen.

 In the past, they didn't have the concept of filling the root canal after devitalizing the pulp.

Note: After devitalizing the pulp, what remains is a dead space where micro-organisms will recolonize.

In 1911, William Hunter (physician) attacked the American dentistry & blamed bridge working for several diseases of unknown etiology because they didn't have the concept of filling which leads to infection & abscess too. They also didn't have an advanced instrument or good restoration materials.
 The findings of bacteriologists added fuel to the fire at Hunter's condemnations.

 Radiography shows a large radiolucent area around the tooth which gave irrefusable evidence of disease surrounding the roots of pulpless teeth.
 Focal septhes theory (1918) "A tooth with abscess inside the oral cavity is considered as a focus of infection that can initiate disease anywhere in the body." (Billings) "One of the most important theories in dentistry".

Examples:

The relation between coronary heart disease & periodontal disease.
 The correlation between periodontal diseases & patients with diabetes.





Modern Endodontology

In 1930, the reemergence of endodontic began as a respectable branch of dental science.

 Concept of apical seal: root canal filling material to the dead, hollow space "hollow space theory" & this material must be stable, non irritant &a sealed apical foramen in order to prevent circulation of tissue fluid inside the root canal after treatment.

 In addition to the apical seal there must be a total (complete) obturation (root canal filling) of the root canal space from the crown to the apex (coronal seal) to prevent circulation of oral fluid inside the root canal system which leads to treatment failure.

 The best way to get rid of the micro organisms in the root canal system is by cleaning (irrigation) & shaping (instrumentation) the root canal space to be able to receive a 3-D root canal filling.

 No amount of chemotherapy that has high antibacterial properties like phenol and phenol derivatives (highly toxic) must be given unless preceded by correct and adequate quantities.

Role of micro organisms
 At the end of the 19th century Miller discovered that bacteria play an important role in the root canal infection.

 Main micro-organisms in the root canal system is bacteroid
(anaerobic).
 Bacteroid( black pigmented bacteria ) which is the major pathogen of root canal, can be classified into :

1- Prevotella 2- Prophyromonas

 Most root canal infections contain a mixture of bacteria (polymicrobial) ; therefore , root canal infection can't be treated by certain antibiotics like other infections.

 Etology : The relative proportion of different bacteria as determined by environmental conditions, it either has synergistic action ( bacteria work with each other) or antagonist action ( work against each other).

 Bacteria travel from inside the tooth chamber to the periradicular region through:

1. A fracture of a crack between the teeth surrounding the tissue.

2. Apical foremen.

3. Lateral accessory canal.

Tissue Response to Canal Infection
 Inflammation is a defense mechanism and not a disease.

Periradicular inflammation which is caused by bacteria & its byproducts in the periradicular region prevent the spread of infection from the tooth into the alveolar bone; otherwise, osteomyelitis occurs.

 In immune compromised patients like patients with (aids), immunity is weak; therefore, bone infection & complete loss of alveolar bone will occur.

 Increased inflammation (bone destruction) appears in radiograph as an increased radiolucent area.

Note:

Inflammation occurs in  periodontal region.
Infection occurs in  Root canal.

 Effective elimination of micro-organisms & bacterial byproducts inside the root canal allow inflammation in the periodontium to subside and regenerating of cementum & bone will occur.

 Inflammatory region contains inflammatory cells like: lymphocytes, microphage, and plasma cells. Their interaction as an antigenic substance results in the release of an inflammatory meditative like neuro-peptide, complement system, lysozyme, metabolites of arachidonic acid which leads to bone destruction.

Notes :
 Prostaglandis and leukotriens play an important role in the development of periradicular lesions.

 A periapical inflammatory lesion develops before it's visible radio-graphically; considerable bone resorption is necessary first.

 Effective elimination of the micro organisms allows inflation to subside and healing to occur.


 Success or failure of endodontic treatment depends on the presence or absence of apical periodontitis ( inflammation of the periodontium).

Therefore:
No inflammation successful treatment.

If there is no infection at the beginning but it occurred later during treatment procedure  failure.

 Root canal treatment can be considered as cure or prevention of apical periodontitis by removing its cause (bacteria and its byproducts)

Scope of Endodontic
1. Diagnose oral and facial (head and neck) pain.

2. Protection of healthy pulp from disease or injury.

3. Pulp capping in injury ( direct or indirect).

4. Pulpotomy: Remove part of the pulp that is injured or carries the disease and maintain the healthy part. (Convential or partial pulpotomy).

5.Pulpectomy : Removal of the whole pulp due to irreversible pulpitis.

6. Root canal treatment if infected root when the pulp is necrotic to prevent arical periodontitis or cure it.

7. Surgical endodontic that includes: apicectomy, hemi-section, & root amputation.


Notes:

 Chemo mechanical approach includes: instrumentation, cleaning, shaping and filling of the root canal.

 Chemotherapy with increased antibacterial properties like phenol and its derivatives that has high toxicity but the rule says "what kills bacteria can kill a living tissue" and we don't want that to happen. Besides, if the instrumentation was wrong and the irritation was bad then the result will not be satisfactory but if we removed this material depending only on instrumentation and irrigation which is called "chemo mechanical debridement of the root canal system" the outcome will be good.

Phases of the Root Canal:
1.Access cavity  How to enter the pulpal tissue with minimal destruction to the tooth structure.

2. Chemotherapy debridement  cleaning (irrigation) and shaping (instrumentation).

3 .Root canal obeturation (filling).

4. Coronal restoration.


Done by : Salaheddin Said Dahbour.