Crown Fractures

Crown fractures represent the majority of dental trauma in the permanent dentition (26–76% of dental injuries), while crown–root fractures only represent 0.3–5%.

The dentist plays a key role, as the success of treatment and prognosis of the traumatised tooth depends on his accurate diagnosis and treatment procedures.

Crown fractures can be broadly classified as follows:

a) Crown Infraction

In this there occurs a crack of enamel and hence is also termed as “Incomplete fracture”. There is no loss of any tooth substance Enamel/dentine cracks are possible pathways for bacterial penetration into the root canal system of teeth.

The application of dentine bonding agent may help prevent infection of the pulp .

Crown infraction

b) Uncomplicated Crown Fracture

These are fractures confined to enamel OR involving enamel and dentine & there is no pulpal exposure.

Uncomplicated crown fracture

Enamel dentine fracture

c) Complicated Crown Fracture

Fracture involving enamel and dentine AND the pulp is exposed.

Complicated crown fracture

Pulp exposure

Treatment of Crown Fracture

i) Restore fractured portion of tooth

ii) Protect pulp

• If pulp is exposed, we have to do partial pulpotomy or pulpectomy depending on stage of root development

• If pulp is not exposed then indirect pulp capping is done.

iii) Finish off with a composite resin restoration. The final restorative treatment for such teeth is deferred until such time that the pulpal status is clear.

Restoring the Fracture

There are numerous methods of restoring the fracture as listed below.

1) Restoration with fragment.

2) Celluloid crown form.

3) Single build-up with matrix.

4) Layered build-up with matrix or partial crown form.

5) Ceramic Veneers

Traumatic Injuries and Their Management

Traumatic injuries to tooth may involve one or the other part of tooth or adjoining periradicular structures. Let us go through them one by one, but before that let us look at the general principles of treating traumatic injuries.

General Principles for Treating Trauma

The general principles for treating trauma that must be kept in mind are:

1) History, examination and assessment

Establish priorities based on the nature and severity of injuries. Potentially life threatening complications need to be handled on priority basis.

2) Protection of

 a) Pulp (if exposed)

 b) Root surface (e.g., during repositioning)

The pulp and root surfaces should be carefully handled to prevent iatrogenic complications and promote healing.

3) Reposition – Immediately of Teeth, bone, soft tissues

All soft and hard tissues should be repositioned and stabilised at the earliest.

4) Stabilisation of

 a) Bone and Teeth: splint (rigid or flexible) .Stabilisation of hard tissues may involve intraoral or extra oral devices .

 b) Soft Tissues: Sutures should be placed as required especially in esthetically critical areas e.g. in cases of split lip. All efforts should be made to promote healing by primary intention.

5) Temporary restorations.

Restorations should be placed at the earliest to protect the pulp and for esthetic rehabilitation.

6) Medications

a) Systemic: tetanus, antibiotics, analgesics, anti-inflammatory agents should be prescribed as necessary.

b) Local: Intra-canal dressings like chlorhexidine gel or Calcium hydroxide paste may be required to promote healing and or prevent resorption.

7) Follow-up- a systematic regime of follow up should be instituted to monitor healing.

Injuries To The Gingiva/Alveolus

GINGIVA

Let us first familiarise ourselves with various types of injuries, which affect the gingiva or oral mucosa.

a) Laceration

• These are shallow or deep wound in the mucosa, which results from a tear usually caused by a sharp object.

b) Contusion

• A bruise caused by a submucosal haemorrhage, from impact by a blunt object with no break in the mucosa.

c) Abrasion

• Caused by rubbing or scraping of the mucosa and is a superficial wound with raw, bleeding surface.

ALVEOLUS

a) Fracture of Alveolar Socket Wall

Fracture confined to the facial or lingual socket wall usually caused by luxation of the tooth within the socket. It is always associated with lateral luxation. It can also be found with other injuries - e.g., avulsion.

b) Fracture of the Alveolar Process

This injury involves fracture of the whole alveolar process, generally detected when there is mobility of multiple teeth as a single unit. It may or may not involve the tooth socket.

Diagnostic Tests

Most of our job is done by the time we have finished taking the history and the clinical examination. These following diagnostic tests further take us to the proper diagnosis and help us to formulate our treatment plan.

Electric Pulp Tester (EPT)

The EPT uses electric current to stimulate the sensory nerves of the dental pulp. Measurement of electric voltage in teeth may be inconsistent due to thickness of enamel and dentin, dryness and electrical resistance of enamel, infractions, restorations, pits, fissures and caries. Where the electric pulp tester is placed on the tooth crown is critical. It has been shown that the incisal edge on anterior teeth and the mesio-buccal incisal edge on lower teeth is the optimal placement site for the EPT to determine the lowest response threshold. This is true of the cold tests as well.

Pulp testers should only be used to assess vital or non-vital pulps; they do not quantify disease, nor do they measure health and should not be used to judge the degree of pulpal disease. Pulp testing gives no indication of the state of the vascular supply, which would more accurately indicate the degree of pulp vitality.

The only way pulpal blood-flow may be measured is by using a Laser-Doppler Flow Meter, not usually available in general practice!

Heat: The tip of a gutta-percha stick may be heated in a flame and applied to a tooth. Take great note that hot gutta-percha may stick fast to enamel.

Cold: Different methods may be used to apply a cold stimulus to a tooth. The most effective is the use of a –50°C spray( Pulpofluorane , Septodont), which may be applied using a cotton pledget. This test is a simple and efficient test for most clinical situations though not necessarily conclusive.

Fibre-optic Light: A powerful light can be used for transilluminating teeth to show interproximal caries, fracture, opacity or discoloration. To carry out the test, the dental light should be turned off and the fibre-optic light placed against the tooth at the gingival margin with the beam directed through the tooth. If the crown of the tooth is fractured, the light will pass through the tooth until it strikes the stain lying in the fracture line; the tooth beyond the fracture will appear darker.

Radiographic Examination

a) Intra-oral views of affected teeth: At least two views should be taken from different angulation to see if there is any fracture line present and occlusal films should be taken to check for the signs of trauma to teeth.

b) Extra-oral views as necessary.

c) Panoramic view: Facial bone projection or CAT scan should be done to see for any fracture lines.

Clinical Examination

A careful, methodical approach to the clinical examination will reduce the possibility of overlooking or missing important details.

Extra-oral Examination

1) Soft Tissue: The soft tissue around the oral cavity, especially the lips and cheeks should be carefully examined for signs of injury, foreign bodies and potentially disfiguring defects which might need immediate attention.

2) Bony Landmarks: These are crucial in determining if there are fractures involving the facial bones. The maxilla, mandible, and temporomandibular joint should be examined visually and by palpation, seeking distortions, malalignment, or indications of fractures. These areas should be followed up radiographically.

Intra-oral Examination

Stepwise examination of the following should be undertaken

1) Soft Tissue Lacerations: The evaluation should be thorough and should include lips, oral mucosa, gingival, hard and soft palate and floor of the mouth. The lips, cheeks, and tongue adjacent to any fractured teeth should be carefully examined and palpated.

2) Tooth Mobility: Mobility should be evaluated and recorded. Examine the teeth for mobility in all directions, including axially. If multiple teeth move simultaneously with the tooth being tested, suspect alveolar fracture.

Root fractures often result in crown mobility, the degree depending on the proximity of the fracture to the crown. The degree of mobility can be recorded as follows: 0 for no mobility, 1 for slight mobility, 2 for marked mobility, and 3 for mobility and depressibility.

3) Occlusion: Derangement in occlusion is often due to facial fractures and may need immediate attention and or alterations in the treatment plan.

4) Clinical Crowns: The crowns of the teeth should be cleaned and examined for extent and type of injury. Crown infractions or enamel cracks can be detected by changing the light beam from side to side, shining a fiberoptic light or light cure light through the crown, or using disclosing solutions. If tooth structure has been lost, note the extent of loss: enamel only, enamel and dentin, or enamel and dentin with pulp exposure. If a crown fracture extends subgingivally, the fractured part often remains attached but loose. Also check for discoloration of the crown or changes in translucency to fiber-optic light. Both may indicate pulp change.

5) Displacement: Note any displacement of the teeth that may be intrusive, extrusive, or lateral (either labial or lingual) or complete avulsion.

6) Sensitivity to Percussion: Denotes injury to periodontal ligament and alveolus include all teeth suspected of having been injured with several adjacent and opposing ones. The results may be recorded as “normal response,” “slightly sensitive,” or “very sensitive” to percussion. Gentle tapping with a mirror handle is the norm. In cases of extensive apical periodontal damage, however, it may be advisable to use the fingertip for percussion.

History Taking

History taking involves obtaining information about the accident in chronologic order to determine what effect it has had on the patient. It is important to know if there has been any treatment before this examination. The patient needs to be questioned about previous injuries involving the same area.

The following questions need to be asked:

1) History: While taking history you must take care of the following points:

a) When did the accident happen? — Record the time and date as closely as the patient can recall. The time elapsed since injury can seriously affect the prognosis as in case of avulsion.

b) How did it happen? — This question provides information on the nature of injury for e.g, blunt or sharp object, direct or indirect blow, all of which will have a bearing on the injury. They also help predict if there could be any concomitant injuries.

c) Where did it happen? — Note the location, for example, car accident, cricket pitch, basketball court etc.

d) Previous injury or treatment. — Prior treatment affects both the treatment plan and the prognosis. If the tooth was avulsed, was it replanted immediately or how soon after the accident? These questions

can provide clues about the standard and quality of emergency care.

e) Have you had similar injuries before? — Repeated injuries to teeth affect the pulps and their ability to recover from trauma, which could alter the treatment plan.

2) General Conditions

Medical history should be enquired about. This is required to detect medical conditions as well as medications given to the patient. It may also be required to provide prophylactic antibiotic therapy for patients at risk. Was the patient conscious? Is there a history of amnesia? - Signs and symptoms to watch for are dizziness; vomiting; severe headaches; seizures or convulsions; blurred vision; unconsciousness; loss of smell, taste, hearing, sight or balance; or bleeding from the nose or ears. Affirmative response to any of the above indicates the need for emergency medical evaluation.

3) Chief Complaint

When diagnosing the origins of pain, most of the diagnosis should be done by what we hear and not what we see. In fact, visual clues might throw us off track resulting in incorrect diagnosis. Once a comprehensive history has been taken the practitioner should in most cases know the diagnosis of the problem.

The clinical examination and diagnostic tests should then be done to ascertain which tooth fits this diagnostic category. The primary goal of the diagnostic procedure is to evaluate whether the disease process is reversible or irreversible, which in turn has a bearing on treatment planning.

Listening carefully to the patient’s description of his/her symptoms can provide invaluable information. It is quicker and more efficient to ask patients specific, but not leading, questions about their pain.

The following questions are absolutely critical

1) How long have you had the pain?

2) Do you know which tooth it is?

3) Does anything initiate the pain or is it spontaneous?

4) How would you describe the pain?

• Sharp or dull
• Throbbing
• Mild or severe
• Localised or radiating

5) How long does the pain last?

6) Does it hurt most during the day or night?

7) Does anything relieve the pain?

8) Does a change in posture modify the intensity of the pain?

9) Does the pain respond to pain medication?

It is usually possible to decide, as a result of questioning the patient, whether the pain is of pulpal, periapical or periodontal origin, or if it is non-dental in origin.

In early pulpitis the patient often cannot localise the pain to a particular tooth or jaw because the pulp does not contain any proprioceptive nerve endings. As the disease advances and the periapical region becomes involved, the tooth will become tender and the proprioceptive nerve endings in the periodontal ligament are stimulated. In cases of pulpitis, the decision the operator must make is whether the pulpal inflammation is reversible, in which case it may be treated conservatively, or irreversible, in which case either the pulp or the tooth must be removed, depending upon the patient’s wishes.

If symptoms arise spontaneously, without stimulus, or continue for more than a few seconds after a stimulus is withdrawn, the pulp may be deemed to be irreversibly damaged. Applications of sedative dressings may relieve the pain, but the pulp will continue to degenerate until root canal treatment becomes necessary. This may then prove more difficult over time, if either the root canals have become infected or if sclerosis of the root canal system has occurred. The correct diagnosis, once made, must be adhered to with the appropriate treatment.

Classification and Examination

The purpose of classifying dental injuries is to provide a description of specific conditions, allowing dentists to recognise and treat using recommended treatment remedies.

Different classification have been discussed in details in the previous unit. The currently recommended classification is one based on the World Health Organization classification (1978) of diseases and modified by Andreasen and Andreasen (1994).

It is also the classification that will be followed in this unit.

Dentofacial Injuries can be categorised into the following categories:

• Soft tissues Lacerations

• Contusions

• Abrasions

• Tooth fractures

• Enamel fractures

• Crown fractures—uncomplicated (no pulp exposure)

• Crown fractures—complicated (with pulp exposure)

• Crown-root fractures

• Root fractures

• Luxation injuries

• Tooth concussion

• Subluxation

• Extrusive luxation

• Lateral luxation

• Intrusive luxation

• Avulsion

• Facial skeletal injuries

• Alveolar process—maxilla/mandible

• Body of maxillary/mandibular bone

• Temporomandibular joint

Diagnosis and Management

In the previous section, we have dealt with the classification and diagnosis of traumatic dental injuries. Now we will discuss about the managment of these clinical situations.

Traumatic injuries to the dentoalveolar apparatus cause numerous injuries in a variety of directions and a variety of magnitudes. The outcome of traumatic events involving teeth depends on three factors: the extent of injury, the quality and timeliness of initial care, and the follow-up evaluation and care. Frequently these injuries require immediate attention and emergency treatment protocols can substantially influence final prognosis.

As a clinician it is imperative to diagnose and treat the injuries on a priority basis not only to improve the health of the dentoalveolar complex but also to satisfy the patients esthetic needs. A large majority of these injuries can be treated efficiently and expeditiously with accurate diagnostic and treatment strategies. In many cases the initial treatment protocol could lead to preservation of tooth vitality and better prognosis. The goal of this unit is to provide the input required for effective clinical management of these injuries. You will learn how to preserve the vitality of the teeth if possible, as well as management of pulpally compromised teeth to ensure optimal healing.

Cracked Tooth Syndrome

Cracked tooth syndrome accounts for many diagnostic problems. These are incomplete fractures through the body of the tooth. The patient complains of pain ranging from mild to excruciating at the initiation or release of the biting pressure when patient bites on a cotton applicator or rubber wheel, fracture segments may separate and pain is reproduced at the initiation or release of biting pressure. This enamel crack may be better visualized using a dye or by transilluminating the tooth with a fiber optic light. Sometimes removal of an intracoronal restoration in the suspected teeth may reveal a

crack in the enamel running into the dentin.

Crack line on the root

The pulp in these teeth may become necrotic or sometimes these teeth fracture completely. If the fracture is incomplete only in enamel and dentin a full crown restoration immobilizing the fragments may be helpful.

Diagnosis

The tooth slooth is a very useful device for differentially diagnosing various stages of incomplete crown fractures. Its design permits selective application of chewing force on one cusp at a time allowing the clinician to evaluate weakness in a define areas of the tooth. It is specially effective when cotton rolls or wooden sticks are not helpful.

Vertical Root Fractures

It is a severe crack in the tooth that extends longitudinally down the long axis of the root often extending through the pulp into the periodontium.

Etiology of Vertical Root Fracture

a) They may arise from physical traumatic injuries.

b) Occlusal prematurities.

c) Excessive parafunctional habit.

d) Resorption induced pathologic root fractures.

e) Most common cause is iatrogenic dental treatment like placement of posts and pins or placing a tightly fitting post or intracoronal restoration. Most common dental procedure leading to vertical root fracture is endodontic treatment.

Diagnosis

History of facial trauma – patients with seizure disorders may be prone to dental trauma history of ice chewing or parafunctional habits or complaint of pain only on biting. A well performed endodontic procedure may suggest a vertical fracture if the tooth does not heal after retreatment or apical surgery.

Transillumination and Dyes

Methylene blue dyes when painted on tooth surface with cotton tip penetrates into cracks and helps in its location. Directing a high intensity light directly on the exterior surface of the tooth a CEJ (cementoenamel function) indicates the extent of fracture. Teeth with fractures block transilluminated light.

Radiographic Evaluation 

Mostly, the fracture is in a plane that is not perceptible from a periapical radiograph. Using a CT scan has shown to be superior to dental radiography in detection of a vertical fracture.

Root Fractures and Cracks

Root Fractures

It is unfortunate to come across root fracture as you are here to save a tooth and if the root of tooth is broken the prognosis is poor. You do come across them in various positions and depths. Following is figure to give you an idea of root fracture classification as given by Hithersay & Morlie.

Hithersay & Morlie's Classification of subgingival fracture

The literal meaning of crack is “breach in continuity”. Following trauma, cracks can be observed in tooth. The cracks can be classified as:

a) Craze lines

b) Fractures

c) Split roots

• Craze lines are merely cracks in enamel, not extending into the dentin. They may occur naturally or secondary to trauma. They are more common in adult teeth and in posterior region. On transillumination these show up as fine lines in the enamel with light being able to transmit through them. They are

mostly asymptomatic and no treatment is necessary unless they do not create a cosmetic problem.

• Fractures (cracks) extend deeper into the dentin primarily extending mesially to distally involving the marginal ridges. Dyes and transillumination help in visualizing potential root fractures.

Crack line on the root

• Split roots – Occur when fracture extends from one surface of the teeth to another surface of the tooth, with the teeth separating into two segments. If the split is oblique, it is possible that smaller fragment may be removed and other saved. But if the split extends below the osseous level, the tooth may not be restorable and endodontic treatment may not result in a favourable prognosis.

Tooth Fractures

• Crown Fracture (Uncomplicated; No pulp exposure)

Crown Fracture

Crown fracture involving enamel and dentine without pulp exposure are called uncomplicated crown fracture by Andreasen and Class 2 fracture by Ellis. These may include incisal-proximal corners, incisor edges or lingual chisel type fracture in anterior teeth and cusps in posterior teeth.'

Incidence

It is very common and accounts for 1/3rd of all dental injury.

Biological Consequences

This Occurs Only

• If only enamel is involved – minimum consequences and complication.

• If dentine is exposed – a direct pathway exists for noxious stimuli to pass through dentinal tubule to the pulp. Pulp may remain normal or chronic pulpal inflammation may occur. It depends on factors like proximity of fracture to the pulp, surface area of exposed dentine, length of time between trauma and treatment and any injuries to the pulpal blood supply.

Diagnosis

• Clinical examination with a mirror and explorer.

• Determination of status of pulp and periradicular tissues by the routine examination procedures.

• Crown Fracture (Complicated; with pulp exposure)

Crown fracture involving enamel dentine and pulp

Crown fracture involving enamel, dentine and pulp are classified as complicated crown fracture by Andreasen and Class 3 fracture by Ellis and Davey.

Incidence

Incidence compared with all types of dental injuries is about 2-3%.

Biological Consequences

A complicated crown fracture if left untreated will always result in pulp necrosis. Bacterial contamination of pulp prevents healing and repair unless exposure is covered. Initial reaction is hemorrhage at the site of pulp wound. Followed by a superficial inflammatory response resulting in either a destructive or proliferate reaction.

Diagnosis:

 It can be made by clinical observation. It is important to evaluate the condition of the pulp.

• Crown Root Fractures

In these fractures enamel, dentine and cementum are involved; pulp may or may not be involved.

Incidence: 

Andreasen reported a 5% incidence of total dental injuries. If crack tooth syndrome and vertical fracture of endodontically treated teeth are also included the total incidence will be higher.

Biological Considerations: 

These are same as complicated or uncomplicated fractures. In addition, periodontal complication are present because fracture may encroach attachment apparatus.

Diagnosis: 

These fractures results in complains of pain on manipulation. Fragments are easy to move and bleeding from periodontal ligament or pulp fills the fracture lines. 

Direct light and transillumination is an effective way of diagnosing these fractures.

• Root Fractures

Root fractures involve the roots only, that is cementum, dentine and pulp.

Root fracture

Incidence: 

These accounts for less than 3 % of all dental trauma.

Diagnosis: 

As these fractures are mostly diagonal in angulation they are often missed radiographically. One additional film angulation of 45 degrees when combined with standard 90 degree reveals most of the traumatic fractures.

Luxation Injuries

These include impact trauma ranging from minor crushing of periodontal ligament and neurovascular supply to the pulp to more major trauma such as total displacement of teeth.

Incidence: Tooth luxation (extruding avulsion) is comprising the largest group of injuries in classification of dental trauma ranging from 30-40%.

There are 5 kinds of luxation injuries:

• Concusion: There is no displacement or mobility. It is characterized by sensitivity to perscussion only.

• Subluxation: There is no displacement but there is increased mobility and sensitivity to percussion.

• Lateral Luxation: Injury may result in displacement of tooth labially, lingually, distally or mesially. This condition is often very painful particularly when tooth is moved into premature occlusion due to trauma.

• Extrusive Luxation: Displacement of a tooth axially in coronal direction results in partial avulsions. Tooth is highly mobile and continuously traumatized by contact with opposing teeth.

• Intrusive Luxation: A tooth may be pushed into its socket resulting in a very firm almost ankylosed tooth.

WHO Classification of Dentofacial Injuries

WHO has given a classification which does not pertain to tooth only but also the soft tissue injuries and facial skeletal injuries. It is discussed as following

a) Soft Tissues

1) Lacerations

2) Contusions

3) Abrasions

b) Tooth Fractures

1) Enamel Fractures

2) Crown fractures – uncomplicated (no pulp exposure)

3) Crown fractures – complicated (with pulp exposure)

4) Crown root fractures

5) Root fractures.

c) Luxation Injuries

1) Tooth concussion

2) Subluxation

3) Extrusive luxation

4) Lateral luxation

5) Intrusive luxation

6) Avulsion.

d) Facial Skeletal Injuries

1) Alveolar Process – maxilla/mandible

2) Body of maxillary/mandibular bone

3) Temporomandibular joint

Now you know about the WHO classification and realise that it is an extensive layout of dento-facial injuries. Let us now go through the final points of tooth fractures and luxation injuries.

Epidemiological Classification of WHO

Traumatic dental injuries according to epidemiology have also been classified by WHO as international classification of disease.

Epidemiological Classification of WHO

WHO Classification of Traumatic Injuries

WHO has classified the traumatic injuries according to the following categories:

1) Injuries to hard tissues or pulp
2) Injuries to periodontal tissues

Injuries to Hard Tissues-Pulp

Injuries to Periodontal Tissues

Ellis and Davey Classification

Diagram to depict Ellis classification

The classification of Ellis and Davey (1970) for dental traumas is as follows:

• Class 1: Simple fracture of crown, involving little or no dentin.

Crown fracture (uncomplicated Ellis Class 1/WHO N502.50)

• Class 2: Extensive fracture of crown, involving considerable dentin, but no dental pulp.

Crown fracture (uncomplicated Ellis Class 2/WHO N502.51)

• Class 3: Extensive fracture of crown, involving considerable dentin and exposing pulp.

Crown fracture (Complicated Ellis Class 3/WHO N502.52)

• Class 4: The traumatized tooth becomes non vital with or without loss of crown structure.

Discolored traumatized tooth (Ellis Class 4)

• Class 5: Tooth lost as a result of trauma.

• Class 6: Fracture of root with or without fracture of crown.

Radiograph showing horizontal root fracture (Ellis Class 6/WHO N502.53)

• Class 7: Displacement of tooth without fracture of crown or root.

• Class 8: Fracture of crown enmasse.

• Class 9: Traumatic injury to deciduous tooth.

Traumatic injury to deciduous tooth (Ellis Class 9)

Classification of Tooth Fracture

In understanding tooth fracture, it is important to categorize them. There are many classifications given by various authors. For us to learn, Ellis etal and WHO classification are imperative to know as they are taught and practiced clinically. To complete the exposure of classifications, we will review few other classifications.

The classification of dental injuries allows data collection worldwide to monitor many aspects of dental traumatology: etiology, incidence and treatment outcome. The dental traumatic injuries can be classified by various methods.

Ellis and Davey Classification

WHO Classification of Traumatic Injuries

Epidemiological Classification of WHO

WHO Classification of Dentofacial Injuries

Etiology and Incidence of Tooth Fractures

Sport activities can lead to dental injuries and have been shown to be common in high school students specially who do not use mouth guards.

Dental injuries can also result from child abuse or “battered child syndrome” and the dentist may be the first health care provider to observe these types of injuries. About 50% of abused children undergo orofacial trauma, intraoral injuries such as tooth and jaw fractures.

Sudden impact to face or head result in trauma to teeth and supporting tissues. Most common causes are falling, traffic accidents, fights, sports. About 20-60% of all traffic accidents produce some injury to facial region. Most dental injuries occur during first two decades of life, mostly occurring during 8-12 years.

Incidence is higher in boys than girls with the ratio varying from 2:1 to 3:1. Maxillary central incisors are mostly involved followed by maxillary lateral incisors and mandibular incisors.

The most common dental trauma involves fracture of enamel and dentin, without pulp involvement.

Andreason reports etiological factors as follows :

a) Human Behaviour

1) Risk taking

2) Peer relationship problems

3) Hyperactivity

4) Stress behaviour

b) Environmental Factors

1) Deprivation

2) Over crowding

c) Unintentional Injuries

1) Falls and collisions

2) Physical leisure activities (sports)

3) Traffic accidents

4) Inappropriate use of teeth

5) Biting hard items

6) Presence of illness, physical limitations or learning difficulties.

Classification of Tooth Fractures

Treatment of traumatized teeth is one of the emergencies in dentistry. It requires good skill, knowledge, experience and presence of mind on the part of the clinician to treat these cases properly. It is important to treat trauma patients on a priority basis to maintain pulp vitality if possible and to timely perform endodontics in pulpally compromised teeth. Timely management is the key to good prognosis in these cases.

Trauma to the teeth may result in either injury of the pulp, with or without damage to the crown and root, or its displacement from its socket. When the crown or root is fractured, the pulp may recover and survive the injury or it may undergo progressive degeneration and ultimately die.

A traumatic dental injury (TDI) results in damage to many dental and periradicular structures. Thus, the management and consequences of these injuries are multifactorial and knowledge of interrelated healing patterns of these tissues is essential.

Traumatic dental injuries have been classified depending on many factors such as etiology, anatomy, pathology, therapeutic considerations and degree of severity. The purpose of classifying dental injuries is to provide a description of specific conditions, allowing the recognition and treatment using recommended remedies.

Requirements of an Ideal Root Canal Sealer

So, now you have come to the stage that you will learn about the sealers. In the previous tutorial you learnt about the various types of sealers used in obturation of the canal. They are many but surprisingly little is known about the relative clinical performance of root canal sealers and most of the time we select the sealer because of following reasons:

a) Riwaaz: You are using a sealer because it was used by your teacher at school, or you were told to use it at your school.

In one of the banquets of the conference you were told by someone to use a particular sealer or that you might have overheard that some one had lot of problem with one type of sealer or the trend now a days is to use this type of sealer.

b) Dental Dealer: Your dealer told you to use a particular brand telling you that this is the best, cheap, effective etc. Have you ever thought as to why you are using a particular sealer? When was the last time you picked-up the literature of the sealer and read to see its – composition/ingredients?

Well let us try to understand the factors to be considered when selecting a sealer.

1) Workability

You know that it is very important that the canal should have more of solid core material rather than the cement. The idea of the cement is like, if you have seen the construction of house. In that, the mason prepares the beam of the building.

He puts in lot of iron rods (Sariya) and then fills the cement in the gaps. Similarly in obturation of the canal, you fill it up with a solid core and the space in between the core is filled up with cement. Sealer acts as a gasket and provides the seal.During compaction it flows to fill irregularities. Lubricate the glide path of gutta percha into the canal. It actively suppress microbial growth and promote hard tissue repair at the root end. As a clinician what is important to you is that you should be able to coat the walls of the canal nicely.

It is important that when you mix the sealer, it should develop a consistency which can be loaded on to the lentilospiral easily, carried to the canal and when the lentilo rotates, it should sprinkle the cement onto the walls uniformly.

Many times you will notice that:

a) Cement is too thin. Try to get the consistency by adding more powder, mixing the particles well. It should be the consistency of the toothpaste or your favourite facial cream.

b) The cement is too thick. If it becomes thick, it bends the lentilo as soon as you try to pick it up the cement becomes like a dry toothpaste. Add more liquid and spatulate.

I personally believe that we hardly follow the manufacturer’s direction regarding dispensing of the powder and liquid. It is important to follow the direction of mixing the cement, as so whether to incrementally add powder with liquid or other wise etc., but when it comes to number of spoons of powder or the number of drops of liquid for a canal, we are more conservative. So it is important for you to get the feel of the consistency required for that. It is also important to know why you need

that consistency.

c) The cement mix is too sticky. Some cements becomes-so sticky that it adheres to the slab, spatula, etc. If it touches to the skin it becomes difficult to remove it. Just avoid such cements.

2) Working time/Setting time

The cement should have an ample setting time. I think the working time or the manipulation time of the cement should be enough for you to be able to mix, carry the cement into the canals. It should give enough time for adequate gutta percha compaction, even in the presence of heat and humidity. Some cements set very fast and it becomes impossible to work with them. Though DYCAL is not an obturation cement but to just give you an example, it is a fast setting cement and doesn't give any chance of proper manipulation. 

3) Adhesiveness to Canal Walls

The cement should have a good adhesion to the walls and help produce a hermetic seal. This is a very important technical property of cement. It is mainly because of these two properties, the cement is used for.

4) Immune Response

The cement should not provoke immune response in the periapical tissues. You should be very careful about this property of the sealer. Many times, if the sealer extrudes in the periapical area, it initially causes acute apical periodontitis followed by swelling in the periapex area. The tooth becomes very tender and the patient needs to take few analgesics in a day. The condition may persist for several days. Many times the filling needs to be removed to give relief from pain.

Endofloss extruded in the periapical area causing an acute inflammatory response

5) Solubility to Tissue Fluid

Many types of cement are soluble in tissue fluid and post obturation recall radiograph shows poor radio opacity.

Zinc oxide eugenol is very soluble cement.left -at the time of obturation and after 12 months

The cement should be retrievable or soluble in solvents, since sometimes removal becomes necessary. Obturate the canal keeping in mind that one day it may need to be repeated. It is better to be in a situation when you can repeat the treatment than to extract the tooth.

The sealer used should be either soluble in commonly available solvents (Obviously not water) or should be such that it can be easily removed mechanically.

7) Radioopaque

The sealer should be radio opaque so that you may come to know the extent of its flow and give a good impression of the filling.

Radiopacity and flow into lateral canals

8) Bacteriostatic: The sealer should be bacteriostatic

There are many other minor ones, which can be read from any standard text.

Requirements for an Ideal Root Canal Filling Material

For years various root canal filling materials have been used. The gold standard properties are the one, still named by Grossman years back.

Properties

The properties of an ideal root canal filling material is as follows:

1) Provide for easy manipulation with ample working time.

2) Be able to seal the canal laterally and apically conforming and adapting to the various shapes and contours of the individual canal.

3) Have dimensional stability; not shrink or change form after being inserted.

4) Not irritate periapical tissues.

5) Be unaffected by tissue fluids and insoluble in tissue fluids, not corrode or oxidize.

6) Be radiopaque, easily discernible on radiographs.

7) Not discolor the tooth structure.

8) Be easily removed from the canal if necessary.

9) Be sterile or can be quickly sterilized immediately before insertion.

10) Be bacteriostatic; at least not encourage bacterial growth.

You have already come to know the various root canal filling materials in the previous units. Silver points, pastes, gutta percha are the most commonly used.

Pastes and silver points fall short of ideal properties of root canal filling material.

Silver Points

Silver points fall short of ideal filling material for the following reasons:

1) Requires an absolutely circular canal preparation.

2) Corrode when in contact with either oral fluids or periradicular tissue fluids.
The corrosive product is highly cytotoxic.

3) Often binds in one or two places on the root canal wall, giving a false sense of fit.

4) Cannot obturate the canal system three dimensionally.

Silver points poorly placed in the canals, retreatment done and filling with gutta percha

Pastes

Pastes fall short of ideal filling material for the following reasons:

1) The apical extrusion of paste is always possible as no apical stop is present.

2) Toxicity results from components of some pastes that either leaches out of paste or in contact with periradicular tissues.

3) Because of porosities in paste fills, most pastes will resorb in time, resulting in apical leakage, and strong possibility of endodontic failure.

4) Chemical components of the paste have been shown to be antigenic, causing immunological responses.

Gutta Percha

Gutta percha provides the bulk of root filling and is presently considered the root canal

obturating material of choice, it is:

• Inexpensive, versatile and easy to handle.
• Adequately bio-compatible.
• Capable of adaptation with pressure, solvents and heat.
• Non supportive of microbial growth.
• It is simple to remove for re treatment and post space.

Same Visit Obturation

Until recently the most accepted technique of doing endodontic treatment stresses multiple visit procedures. Most schools also concentrated upon teaching the multivisit concept. However, it has now been reported that the procedure of single visit treatment is advocated by at least 70% of schools in all geographical areas.

Some of the problems of root canal treatment are post-obturation pain, interappointment pain and swelling. Although these in most cases do not last long, but could be a source of embarrassment to the dentist and annoying for the patient, more so if the tooth was symptomless before the commencement of treatment.

Literature review revealed varied opinions on the incidence and severity of postobturation pain. Some authors reported slightly more post-obturation pain following single visit than with multiple visit procedures. Others found no significant differences in the post-obturation pain experienced by patients following single or multiple visit treatment procedures. Some authors however, proposed a correlation between pretreatment pain and post-obturation discomfort. The rate of endodontic flare-ups was reported to be more following multiple visits than for the single visit.

Some studies have reported a positive correlation between flare-ups and multiple appointments, peri-radicular pain prior to treatment and presence of radiolucent lesions. Others reported no correlation between post-obturation flare-ups and the status of the pulp. However, few reported a significantly higher incidence of flareups in necrotic teeth than in vital teeth. One study showed that female patients had more post-operative pain than did males. Factors of age, bacteriologic status, tooth position and type of filling material showed no clear effect upon postoperative results.

Three contradictions exist in completing a root canal treatment in one appointment:

A) Inability to dry the canals completely.

B) Insufficient time to complete the procedure.

C) Increased psychological stress on patients or clinicians because of longer appointment time, or both.

Now the question is what should you do?

What is the hurry? It is best to start with a multiple visit endodontic treatment. It takes many cases for you to develop your confidence in root canal treatment. 2-3 cases of post obturation tenderness in 2-3 days of time can very well shake your confidence and patient's moral to under go the treatment or to recommend to any one else.

If you can follow the complete protocol of root canal treatment including use of rubber dam, use of apex locater, engine driven rotatory with autoclaved files and spend good amount of time in bio-mechanical preparation and obturation, you may think of a single sitting root canal treatment.

When to Obturate the Canal

Regardless of the material and the technique used, certain parameters should be met before the canal is considered ready for filling.

There are various schools of thoughts illustrating these parameters. These thoughts come from the clinical experiences of various practitioners and research of scientists. We always believe that endodontics moves with the clinical symptoms and signs. Listen to the tooth and it tells you what to do. To listen to tooth you need to know its language. It speaks in various languages. These languages when interpreted by your knowledge and your experience becomes the parameter. The important parameters are:

1) The Tooth is Asymptomatic. (The tooth is tamed)

This happens to be the first and the most logical and simple requirement for obturation. The tooth is lightly tapped with the butt end of a mouth mirror and by digital manipulation of the buccal and lingual plates of the bone surrounding the tooth. There should be no sensitivity or pain/tenderness during percussion or palpation. The presence of sensitivity indicates inflammation in the periodontal membrane space. If the canal is filled before the inflammation has subsided, the additive inflammation of filling, packing the canal, will cause extremely painful episode. Unless tissue resistance is strong enough to overcome this considerable increase of inflammatory potential, an area of periapical inflammation will result or a previously existing lesion will recur.

2) The Canal is Dry (The tooth is not crying)

It is important to check with the paper points that the canal to be obturated is free of all the exudates and is dry. This is done for two reasons.

a) Exudates from the canal is indicative of some infection. You will many times come across cases of weeping canals. Calcium hydroxide preparation helps to dry the canal.

b) Canal needs to be dry at the time of obturation for the adaptation of the filling material to the canal walls.

3) Presence of Sinus

It is controversial as to whether to do obturation in the presence of sinus or not. First find out the amount of bone loss and stability of tooth. Prepare the canal and ask for a follow-up after 2-3 days. If you find that the sinus shows signs of healing, canals are dry and tooth asyptomatic— you may obturate without waiting for the sinus to heal completely. Follow-up the patient to check the progress.

The presence of sinus is not a contraindication for filling. You may rather consider it as advantageous, as post-operative pain rarely occurs when ever the canals are filled with periapical sinus present.

Extension root of the sinus seen. (Vitapex extruding out of sinus and the distal pocket)

4) Foul Odour (The Canal smell ill)

Many years ago in my days of graduation my teacher used to tell two methods.

1) I was told to smell the paper point, used as a root canal dressing, and check for any foul odour.

2) The paper point was then dipped in hydrogen peroxide to check for any effervescence.

The logic was that, if there was a foul odour then canal was infected. The effervescence was an indication of the exudates.

Researches later reported a poor correlation between canal odour and culture results. Positive cultures were found in canals free of odour. In addition, a foul odour has been associated with anaerobic growth, which is difficult to verify without routine culturing technique. You should not consider absence of canal odour alone as any indication for filling. It must be correlated with other clinical

findings.

5) Negative Culture Test

This has been a dominating criterion for many years. It has been statistically found that there will be an average of 11% more success in healing when teeth are filled with negative culture. The probability of post-filling discomfort is more when the root filling is done into infected canals.

6) Temporary Filling is Intact

A breach or a washed off temporary filling is an indication of seepage of saliva in the canal. This may be presumed as a case of infected canal. You should always fill the temporary filling as if, you are filling it permanently. I have seen that temporary filling is always done with a very heavy heart. It is always considered to be temporary but is intended to work as permanently. The temporary filling should hermetically seal to prevent leakage of the canals and be strong enough to withstand the masticatory forces.

7) When you have enough time to achieve quality seal.(hungry, hurry, haphazard) It is a fact that you cannot do a good obturation if you are hungry, in a hurry or haphazardly organized.