Post-endodontic restoration and long-term outcome

The final coronal restoration could influence the

outcome of endodontic treatment. The restoration

should provide adequate coverage to protect the

endodontically treated tooth against fracture, which

could ultimately lead to extraction.

Other potential problems associated with the final restoration playing a

role in the breakdown of root canal treatment include

a permanent restoration with marginal breakdown, or

bacterial penetration due to restorative procedures such

as post space preparation.

Both will result in micro-organisms invading the filled root canal space after

treatment.

Endodontic treatment sequence

General overview

The treatment sequence may be planned into a

number of stages including: (1) initial cause-related

therapy, e.g., emergency pulp extirpation; 

(2) re-examination, e.g., response to initial endodontic

treatment; (3) corrective treatments, e.g., complete root

canal treatment and restorative treatment; and 

(4) maintenance, e.g., measures to prevent the disease

recurrence.

When to refer and when to perform endodontic retreatment

Dentists should be able to assess when the difficulty

of the treatment exceeds their skill and be able to refer

the patient to an endodontist as necessary.

Sometimes, diagnosis and the decision to treat endodontically are

easily achieved, but the technical difficulty of the case

dictates that the patient be referred to an endodontist

for management.

Prognosis of endodontic treatment

The prognosis for endodontic treatment of the tooth

or teeth in question must be taken into account in the

treatment planning. treatment planning. Data regarding the outcome of
endodontic treatment should be interpreted with
caution because different studies lack standardization
and vary in material composition, treatment procedures
and methodology, i.e., prospective or retrospective in
the study design.

The main reason for the variability

Whether the tooth can be restored and its replacement options

Extraction of the tooth is a valid treatment if

endodontic therapy is not applicable or where

endodontics would succeed, but successful completion

of the treatment plan is impossible because of

periodontal or restorative issues.

The tooth concerned

must be assessed for any restorative challenges that

would deem the tooth as unrestorable following root

canal treatment. Figure 4 shows a radiograph of a

patient with a severe restorative problem of tooth 36

because of the extensive subgingival restoration.

Removable partial dentures are often a simple and

relatively inexpensive tooth replacement option, but

Patient factors

The dentist should be aware that some patients will

opt to have an extraction of a tooth on the grounds of

time involved in treatment, fear of treatment, lack of

confidence that root canal treatment is likely to be

successful or the total cost involved.

Although medical

conditions (e.g., diabetes, or habitual tobacco smoking)

may complicate or delay healing, in general, medical

reasons are not a contra-indication to root canal

therapy. However, conditions which limit a patient’s

ability to lie supine (e.g., spinal arthritis), to open the

mouth wide (e.g., rheumatoid arthritis), or to tolerate

rubber dam (e.g., anxiety disorders), may make

Periodontal factors

The health of the periodontium needs to be assessed

because in a compromised dentition, the long-term

prognosis for retaining a single tooth may be poor.

General overview of endodontic treatment planning

he primary concern is the long-term preservation of

a healthy functional dentition. The concept of treating

the dentition as a functioning unit is in conflict with

traditional dental practice in which the tooth, rather

than the dentition, is often the focus of concern.

The dentist should consider the strategic value of the tooth

to be endodontically treated in relation to the overall

function of the dentition. For example, a 2nd molar or

General overview of endodontic treatment planning

The selection of cases for endodontic therapy should

take into consideration the prognosis of the

endodontic, restorative and periodontal procedures.

4

The flow chart (Fig 1) provides a diagrammatic 

outline of the decision-making process for treatment

planning in endodontics. Once appropriate diagnostic

tests have confirmed the pulpal and periradicular

diagnosis, immediate treatment of the tooth may be

required if relief of painful symptoms is needed. For a

patient in pain, the dominating concern by the dentist

is whether endodontic treatment will rapidly and

predictably eliminate the patient’s pain and

discomfort.

5

Following stabilization of the tooth, the

dentist should exercise caution in deciding whether the

tooth concerned has a good or poor prognosis. Issues to

consider when making this judgement include: 

(1) strategic value of the tooth; (2) periodontal factors;

(3) patient factors; and (4) whether the tooth can be

restored or are there alternative replacement options.

Although certain teeth are endodontically treatable, the

amount of tooth structure remaining may not be

readily restorable, and a durable coronal restoration is

not achievable.

Of equal importance, the periodontal

condition of the tooth must be assessed prior to

endodontic therapy because optimal periodontal health

is critical to the long-term success of teeth that are

endodontically treated.

It is essential to consider the

patient’s needs, attitude and willingness to accept

treatment.

Subluxation

This injury is characterized by abnormal loosening of

the tooth but without displacement. Teeth are tender to

percussion and there may be some bleeding in the

gingival crevice. Prognosis for subluxation injuries is

good. Endodontic management is, however, sometimes

necessary.

Reported frequency of pulp necrosis ranges

from 6 to 17 per cent. Pulp canal calcification has been

reported to occur in 9 to 12 per cent of the cases and

progressive root resorption in less than 2 per cent.

Treatment planning the endodontic case

Following a definitive diagnosis of the need for root

canal treatment, the treatment planning stage should

be straightforward if a logical sequence of decision-making is followed. 

Very few contra-indications

exist for providing root canal treatment, but the

planning must include several aspects. Firstly, is root

canal treatment best for the patient to maintain a

functional dentition long term? Secondly, who

should provide the treatment? Thirdly, what are the

restorative options that will ensure the best long-term prognosis? 

The sequencing of root canal

treatment generally occurs early in a typical treat-ment plan, 

and prompt restoration after treatment is

crucial to long-term survival of the tooth

Disease progression

The two key components in pulp inflammation are

the microcirculation and the sensory nerve activity.

Injury to the pulp may activate the intradental sensory

nerves to release neuropeptides, which in turn cause

alteration of microcirculatory haemodynamics.

The response of sensory nerves to stimuli depends

upon the severity of the pulp injury and the stages of

inflammation. Within the first few minutes of injury,

destruction and disruption of nerve fibres in the injured

dentine and pulp occurs, followed by hypersensitivity

of the surviving nerve fibres and the release of

neuropeptides into the pulp. Inflammatory mediators,

such as bradykinin and the prostaglandin E, may also

evoke the neurosecretion of CGRP.

These neuropeptides cause vasodilatation and

Pathogenesis

Mild and moderate injury to the odontoblast cell

processes may produce tubular sclerosis and reparative

dentine, but prolonged or severe irritation can cause the

death of the odontoblasts and initiation of an

inflammatory response. The dynamics of pulp

inflammation is not different to that of inflammation in

the periapical and other tissues. Depending on the

severity and duration of the irritants, the pulp response

ranges from reversible to irreversible pulpitis, then to

partial necrosis which leads to total necrosis. This may

occur without pain.

The dental pulp may also

respond to irritation with a range of degenerative

changes including fibrosis and calcification.

Inflammation

Others

Pulps age! With age, nerve and blood supply to the

pulp tends to decrease, and the pulp becomes more

fibrous and less cellular.

As a result, the pulp may

become less equipped to mount a defensive reaction to

injuries. However, dentine permeability reduces with

age as a result of a progressive reduction in tubular

diameter and an increase in the formation of peritubular

dentine. This provides a more protective environment

for the pulp.

Chemical

Most of the current restorative materials are relatively
inert. However, it is usually bacteria penetrating the
restoration margins which causes pulp inflammation,
rather than the chemicals themselves.

Iatrogenic factors

Paradoxically, the very dental treatment designed to

repair the tooth may do harm to the dental pulp. Cavity

preparation is a common cause of pulp inflammation.

High-speed cutting is superior to low-speed even when

air and water coolant are used but some degree of pulp

irritation will still occur. Heat, cutting depth (within

0.5mm of the pulp) and dehydration cause damage to

the pulp. Pin insertion can crack dentine and predispose

the tooth to bacterial infection. Large restorations may

cause cracks in teeth when under load. Pressure from

condensing restorative materials may intensify pulp

responses induced by the cutting procedure. Acid

etching, a common procedure in adhesive dentistry,

removes the smear layer and this may allow bacteria to

enter the dentinal tubules.

Bacteria

Bacterial infection is the most frequent cause of pulp

and periapical diseases.

96-101

Bacteria may enter the

tooth via caries,

102-105

dental anomalies (e.g., dens

invaginatus, deep lingual and palatal grooves), exposed

lateral canals or damaged cementum as a result of

periodontal diseases, tooth cracks or fractures,

and marginal breakdown at the restoration-tooth

interface.

Bacterial infections of the pulp space consist of 

mixed microbial and predominantly anaerobic flora.

Trauma

Trauma from accidents or bruxism may cause pulp

inflammation. Crown fractures may provide a pathway

for microbial invasion

which can lead to pulp necrosis

and infection of the root canal system. Root fractures

affect the pulp differently since they may disrupt the

pulp vascular supply within the portion of the tooth

that is coronal to the fracture line and this can lead to

necrosis of the pulp in that segment of the tooth.

However, the rate of survival of the pulp following root

fractures is high and the pulp can initiate a callus-like

form of healing at the fracture site, especially in

Diseases of the pulp

The dental pulp may be exposed to a number of
irritants that are noxious to the health of the pulp and
jeopardize the functions of the pulp. They may be either
constant irritants or specific events that interfere with
the pulp blood supply (Table 1). Irritants can be
classified as being short-term, long-term or due to
trauma. Each type of irritant or injury will have a
different effect on the pulp – in general, the effects will

Neurogenic inflammation

Activation of sensory nerves in the pulp (either by

electrical stimulation of the inferior alveolar nerve or

directly on the tooth crown) induces a long-lasting

blood flow increase in the pulp and increased vascular

permeability. Furthermore, excitation of A- fibres

seems to have an insignificant effect on pulp blood flow

(PBF), whereas C fibre activation causes an increase in

PBF. Neurogenic inflammation is thought to be mediated

by neuropeptides released from sensory nerves, such as

substance P (SP) and calcitonin-gene-related-peptides

(CGRP), and possibly the reactive oxygen species at the

site of inflammation.

Sympathetic nerves

A sympathetic adrenergic vascular control exists in

the dental pulp.

Mediators presently known are

noradrenaline and neuropeptide Y. The sympathetic

nerve fibres originate from the cervical sympathetic

ganglion, and after joining the trigeminal nerve at its

ganglion, most of them follow the course of the sensory

nerves to the teeth, or they possibly travel via the blood

vessels. Sympathetic vasoconstriction is typically

activated by stress stimuli and by painful stimuli directed

at almost any part of the body. Sympathetic vaso

constriction may modulate the excitability of the sensory

nerves. In the compromised pulp, sympathetic vaso

Pulp nerves

The dental pulp contains both sensory and autonomic

nerves to fulfill its vasomotor and defensive

functions.

Sensory nerves

The sensory nerves, which are involved in pulp pain

perception and transduction, are branches of the

maxillary and mandibular divisions of the trigeminal

nerve. The small branches enter the apical foramina

and progress coronally and peripherally following the

route of the blood vessels, and they branch extensively

subjacent to the cell-rich zone, forming the plexus of

Raschkow. The plexus contains both large myelinated

A- and A- fibres (2–5µm in diameter) and the smaller

unmyelinated C fibres (0.3–1.2µm). At about the level

of the cell-rich zone, myelinated fibres lose their myelin

sheath. In the cell-free zone, they form a rich network

of free nerve fibres that are specific receptors for pain.

From there, the free nerve terminals may enter the

odontoblastic layer, and penetrate into the predentine

zone or to the inner dentine next to the odontoblastic

cell process, but not every dentinal tubule will contain

nerve endings. Myelinated nerves do not reach their

maximal development and penetration into the pulp

until the tooth is fully formed, which may explain why

young teeth are less sensitive than adult teeth. The

branching of nerve axons has been observed not only

within the pulp but also occurs in the periapical region

where these axons may branch to supply the pulps of

adjacent teeth just prior to entering the pulp.

Control of pulp blood flow

There has been some disagreement as to whether the

pulp microcirculation is capable of functional regulation.

Pulp blood flow in anaesthetized animals is dependent

on alterations in systemic blood pressure.

Stealing perfusion of the surrounding tissues has been implicated

in the paradoxical decrease in pulp blood flow in

response to arterial infusion of well-known vasodilators

in other circulations.

“Stealing” of the blood supply to

the dental pulp is thought to occur when vasodilation

of the neighbouring tissues reduces the perfusion

pressure to the pulp, thus producing a decrease in the

blood flow to the pulp.

Functions of the pulp microcirculation

The primary function of the pulp microcirculation, in

common with all circulation in the body, is to supply

oxygen and nutrients to its constituent cells, as well as

providing an exit route for metabolic waste products

from the tissue. Blood is brought to the tissue through

pulp arterioles. Oxygen, nutrients and wastes are

exchanged in capillaries by diffusion, and waste

products are removed by pulp venules. In general,

blood flow to any organ must be high enough to ensure

sufficient oxygen and nutrient supply. On the other

hand, an excessively high blood flow level is undesirable

as it leads to a waste of energy. Hence, it is plausible

that the main purpose of the relatively high blood flow

in the pulp is to serve the pulp cells, perhaps the

odontoblasts in particular, with important nutrients in

an adequately high concentration in the capillary bed.

Special features of the pulp with respect to its circulation

The dental pulp has an unusual combination of

features that makes its circulation rather unique.

Firstly, the compliance of the pulp is low because it

resides in a rigid, unyielding calcified wall. A near

simultaneous increase in pulp tissue pressure has been

recorded as a result of vasodilatation.

Because capillary dilation and the transudation of fluids that

comprise the early stages of acute inflammation

increase the volume of tissue, such swelling in the

dental pulp is likely to cause a pressure increase that

stimulates pulp nerves to register pain. Secondly, the

dental pulp is a firm and resilient connective tissue,

composed principally of a gelatin-like material, such as

proteoglycans and other glycoproteins, reinforced

throughout by irregularly arranged and interlaced

collagen fibres. The resilient ground substance limits

intrapulpal pressures to the site of irritation, and is not

transmitted throughout the pulp space.

Pulp microcirculation

The resilience to noxious insults and the inherent

healing potential of the dental pulp is well recognized.

Since the pulp is relatively incompressible, the total

volume of blood within the pulp space cannot be greatly

increased. Hence careful regulation of pulp blood flow

is of critical importance and alterations in pulp micro-circulation 

may be the first to occur with the onset of

pulp inflammation.

In general, the pulp microcirculation is supplied

through the maxillary artery, which is a branch of the

external carotid artery. The maxillary artery leads into

the dental artery and enters the tooth via arterioles

feeding each individual pulp microvasculature. Pulp

vessels are arranged in a hierarchical system:

the arterioles course up centrally and give off branches to

form a capillary network at the periphery of the pulp

and the blood drains into venules at the centre of the

pulp. The capillary network provides the odontoblasts

with a rich source of nutrients. The vascularity of the

pulp is comparable with that of the most vascular parts

of the brain and the tongue, indicating that the pulp 

is a highly vascular tissue.

Odontoblasts

resides within a dentinal tubule, which is like a

capillary tube with a diameter that is much smaller than

that of an erythrocyte. Microtubules and microfilaments

are the principal components of the process, providing

infrastructure for transportation from the cell body to

the remote cell process.

In addition to a role in forming dentine, odontoblasts

may be involved in sensory transduction.

The presence of tight, adhering and gap junctions may

imply that these cells communicate with each other;

and if one is affected, many others are also affected.

Gap junctions exist between and among odontoblasts

and nerve fibres,

and they provide a pathway of low

electrical resistance between and among the odonto-blasts and nerve fibres. 

The hydrodynamic effects of

fluid displacement within the dentinal tubules or the

odontoblasts may activate mechanoreceptors of sensory

nerve axons.

Functions of the dental pulp

A fundamental question that needs to be addressed is

whether the dental pulp is necessary in a fully formed

tooth. One can argue that the tooth can continue to

function normally after the pulp is removed and

replaced with a root canal filling. In such situations, the

circulation of the periodontal ligament and the

surrounding tissues will support a pulpless or an

endodontically treated tooth.

A recent study on the bacterial invasion into dentinal

tubules of human teeth with or without viable pulp has

shown that teeth with pulps are much more resistant to

bacterial invasion into the dentinal tubules than are

teeth with root canal fillings.

In the latter, bacteria are

able to enter teeth and reach the root canal system in a

relatively short period of time.

The dental pulp and its nature

The dental pulp derives from neural crest cells (the

ectomesenchyme). Proliferation and condensation of

these cells lead to formation of the dental papilla from

which the mature pulp is derived. The mature pulp

bears a strong resemblance to the embryonic connective

tissue, with a layer of highly specialized cells, the

odontoblasts, along its periphery.

The physical

An overview of the dental pulp: its functions and responses to injury

The dental pulp is a unique tissue and its importance
in the long-term prognosis of the tooth is often
ignored by clinicians. It is unique in that it resides in
a rigid chamber which provides strong mechanical
support and protection from the microbial rich oral
environment. If this rigid shell loses its structural
integrity, the pulp is under the threat of the adverse
stimuli from the mouth, such as caries, cracks,
fractures and open restoration margins, all of which
provide pathways for micro-organisms and their
toxins to enter the pulp. The pulp initially responds
to irritation by becoming inflamed and, if left
untreated, this will progress to pulp necrosis and
infection. The inflammation will also spread to the
surrounding alveolar bone and cause periapical
pathosis. The magnitude of pulp-related problems
should not be underestimated since their most
serious consequence is oral sepsis, which can be life
threatening, and hence correct diagnosis and
management are essential. Clinicians must have a
thorough understanding of the physiological and
pathological features of the dental pulp as well as the
biological consequences of treatment interventions.
Key words: Dental pulp, pulp disease, inflammation,
necrosis.

CONCLUSION

Infection of the root canal is not a random event. The

type and mix of the microbial flora develop in response

to the surrounding environment. Factors that influence

whether species die or survive are the particular

ecological niche, nutrition, anaerobiosis, pH and

competition or cooperation with other micro-organisms. 

Whether it is a necrotic pulp or root-filled

space, the environment selects for micro-organisms that

possess traits suited to establishing and sustaining the

disease process.

Antimicrobial effect of chemical agents

The antibacterial effect of mechanical preparation

with saline as an irrigant has been shown to be

inefficient in the elimination of bacteria from the root

canal.

This implies that mechanical instrumentation

of the canal must be supplemented by antibacterial

irrigants and dressings for efficient elimination of

micro-organisms from the root canal. There are many

other benefits to be gained by the use of chemical

agents during the preparation of the root canal. The

agents used for chemical disinfection can be separated

into two types — those used for irrigation during canal

preparation and those used as an intracanal dressing

between appointments.

Irrigation

Clinical implications of apical enlargement

Even though the use of rotary NiTi instrumentation

allows curved roots to be widened to sizes 45 to 80,

there is a question about the effect of such enlargement

on tooth structure. More than 25 years ago, cleaning to

large apical sizes was advocated

and was fraught with

procedural clinical problems, mainly associated with

iatrogenic damage to the fine structure of the apical

third of the root. The difference between the stainless

steel instruments of that time and NiTi instruments of

today is that the increased flexibility of NiTi

instruments reduces the chance of deviation from the

original canal anatomy during instrumentation.

However, an open question is: compared with

conservative techniques of apical preparation, does

apical enlargement provide better clinical results and

with a suitable margin of safety? 

Observation of the results of those practising

techniques of apical enlargement has shown that, apart

from in the hands of the most highly skilled clinicians,

there are many procedural risks associated with apical

enlargement. Some of the potential procedural problems

associated with enlarged apical instrumentation are

summarised in Table 5. 

Importance of asepsis

Since the primary goal of endodontic therapy is the

elimination of bacteria from the root canal, an essential

requirement during treatment is that it be undertaken

in a sterile environment where further contaminating

micro-organisms can be reliably excluded from the

canal. The treatment of root canal infections is unique

in the sense that it is possible to isolate the area from

Antimicrobial effect of debridement

The control of bacteria within the root canal might

appear to be straightforward since such a large

proportion of the bacterial flora is sensitive to oxygen.

However, the penetration of oxygen into the canal

during treatment does not seem to have any significant

effect on the bacteria. The reason for this is that many

of the bacteria are protected in the irregularities and

branches of the root canal system and in dentinal

tubules. Only a few cells need to survive treatment so

that when the canal is closed, the anaerobic milieu will

be restored and the bacteria can re-multiply. The

Antimicrobial efficacy of manual instrumentation

Infected root canals can harbour between 10 to

more than 10 bacterial cells.

Manual instrumentation

with 6–10ml of saline per canal can reduce the number

of bacteria in infected root canals by 100 to 1000-fold.

However, root canal preparation with hand files

and saline irrigation is only moderately effective. Early

studies in which no antiseptic irrigants were used

Antimicrobial efficacy of rotary NiTi instrumentation

Engine-driven instruments make canal preparation

faster and less tedious than hand instrumentation. The

flexibility of nickel-titanium rotary instruments

facilitates shaping of curved canals and enables the

clinician to instrument canals to the desired tapered

form with a high degree of consistency. 

The antimicrobial effectiveness of instrumenting

canals with rotary nickel-titanium instruments is in line

with the results seen with manual instrumentation of

root canals.

Does apical enlargement eliminate infection?

A number of studies have suggested that apical

enlargement may reduce the microbial flora compared

with instrumentation to smaller file sizes. These studies,

some of which are listed in Table 3, have been

performed under different conditions with divergent

results. On the basis of selected findings, some authors

have advocated that it should then be possible to

complete endodontic treatment in one visit if cleaning

to a large apical size completely eradicates bacteria. 

Transient apical internal resorption

Transient apical internal resorption is another form

of trauma induced non-infective root resorption which

was identified by Andreasen in 1986.

This resorptive process can follow luxation injuries and may be

associated with a transient apical breakdown –

recognized by a confined periapical radiolucency which

resolves within a few months. It is considered to be a

positive response, with the internal apical resorption

allowing ingress of a greater vascular network to aid in

the healing of a traumatized pulp. Often there is an

associated colour change due to intra-pulpal

Conditions for persistent infection

In a study that examined the influence of infection at

the time of root filling on the outcome of treatment,

68 per cent of teeth that were infected at root filling

healed after the treatment. Similar results have also

been reported in other studies.

Properties of species associated with persistent endodontic disease

With the exception of Actinomyces, which is primarily

involved in extraradicular infection, other species

commonly associated with persistent intraradicular

infection such as candida and enterococci can be  viewed

as opportunistic pathogens. A shared behaviour is that

they leave their normal habitat in the oral cavity and

establish in the root canal where they take advantage of

the ecological changes and that their microbial

Ecological differences between untreated and root-filled root canals

The untreated infected root canal is an environment

that provides micro-organisms with nutritional

diversity in a shifting pattern over time. The available nutrients 

are mainly peptides and amino acids, which

favour anaerobic proteolytic species. 

Whilst the microbial flora in an untreated infected

root canal may experience feast, in the well-filled root

Microbiology of canals with persistent infection

Usually one or just a few species are recovered from

canals of teeth with persistent disease. These are

predominantly Gram-positive micro-organisms and

there is an equal distribution of facultative and obligate

anaerobes.

This microbial flora is distinctly different

from infections in untreated root canals, which typically

consists of a polymicrobial mix with approximately

equal proportions of Gram-positive and Gram-negative

species, dominated by obligate anaerobes. 

There is some diversity of species isolated from root-filled 

teeth with persistent periapical disease, but there

is a consensus amongst most studies that there is a high

prevalence of enterococci and streptococci.

Flora in root-filled canals

It is generally acknowledged that persistence of

disease is most commonly due to difficulties that occur

during initial endodontic treatment. Inadequate aseptic

control, poor access cavity design, missed canals,

inadequate instrumentation, and breakdown of

temporary or permanent restorations are examples of

procedural pitfalls that may result in persistence of

endodontic disease (Fig 1). 

Contribution of molecular techniques

An improved systematic structure has been made

possible with the application of molecular tools to

obtain data from 16S rRNA gene sequences,

which allows enhanced differentiation between micro-organisms and led to the establishment of new genera

and species. During the last decade, molecular

techniques have been used for microbial identification

of root canal samples. Many of the species that are

reported as new are split off from previously established

genera and species, but the ease of identifying culture-difficult species and the specificity of PCR-based

methods has meant that some additional species can be

Classification of perio-endo lesions

Class 1. Primary endodontic lesion draining through the periodontal ligament

Class l lesions present as an isolated periodontal pocket or swelling beside the tooth. The patient rarely complains of pain, although there will often be a history of an acute episode. The cause of the pocket is a necrotic pulp draining through the periodontal ligament. The furcation area of both premolar and molar teeth may be involved. Diagnostically, one should suspect a pulpally induced lesion when the crestal bone levels on both the mesial and distal aspects appear normal and only the furcation shows a radiolucent area.

Class 2. Primary endodontic lesion with secondary periodontal involvement

If left untreated, the primary lesion may become secondarily involved with periodontal breakdown. A probe may encounter plaque or calculus in the pocket. The lesion will resolve partially with root canal treatment but complete repair will involve periodontal therapy.

Root removal and root canal treatment

To prevent further destruction of the periodontium in multirooted teeth, in may be necessary to remove one or occasionally two roots. As this treatment will involve root canal therapy and periodontal surgery, the operator must consider the more obvious course of treatment, which is to extract the tooth and provide some form of fixed prosthesis. As a guide, the following factors should be considered before root resection:

1 Functional tooth. The tooth should be a functional member of the dentition.

2 Root filling. It should be possible to provide root canal treatment which has a good prognosis. In other words, the root canals must be fully negotiable.

3 Anatomy. The roots should be separate with some inter-radicular bone so that the removal of one root will not damage the remaining root(s). Access to the tooth must be sufficient to allow the correct angulation of the handpiece to remove the root. A small mouth may contra-indicate the procedure.

4 Restorable. Sufficient tooth structure must remain to allow the tooth to be restored. The finishing line of the restoration must be envisaged to ensure that it will be cleansable by the patient.

5 Patient suitability. The patient must be a suitable candidate for the lengthy operative procedures and be able to maintain a high standard of oral cleanliness around the sectioned tooth.

BALANCED EXTRACTIONS VERIFIABLE CPD PAPER NOW AVAILABLE AS A BDJ BOOK

Primary teeth with pulpal exposure or pathology must always be treated, either by root canal treatment or by extraction. The maintenance of arch length is important for good masticatory function and the future eruption of the permanent dentition with optimal development of the occlusion. Whilst it is preferable to conserve a tooth rather than carry out an extraction, if this does become necessary, balanced extractions should always be kept in mind. A balanced extraction is the removal of a tooth from the opposite side of the same arch. A compensating extraction, removing a tooth from the opposing arch to the enforced extraction is more difficult to justify.

Balanced extractions are rarely justified for primary incisors. The loss of a primary canine, however, may have a significant effect on the arch and balanced extractions should always be considered. When a primary molar has to be extracted it may be preferable to prevent drifting with a space maintainer than carry out balanced extractions.

ENDODONTIC TREATMENT OF PRIMARY TEETH

Endodontic treatment may be indicated far earlier when treating the primary dentition than in permanent teeth. Obviously, treatment is indicated when a patient presents with a pulpal necrosis, or symptoms of pulpitis. However, the distinction of reversible or irreversible pulpitis applied to the permanent teeth is not so relevant in the primary teeth; any sign or symptom of pulpitis indicates the need for pulp therapy. Current research and practice also suggests that pulp therapy will be necessary when a radiograph shows a carious lesion extending more than halfway through the dentine, or where the carious process has led to the loss of the marginal ridge.

However, there are important assessments to be made as to the patient’s suitability for endodontic treatment. The general health of the patient should be checked to ensure that there are no contra-indications to endodontic therapy, such as those with congenital heart disease, or patients 

Diagnosis

The reaction of pulp tissue in primary teeth to deep caries differs from that seen in the permanent dentition and is characterised by the rapid spread of inflammatory changes throughout the coronal portion of the tooth. These pathological changes become irreversible and, if left untreated, will involve the radicular tissue. There may be few, if any, clinical symptoms in the early stages to indicate the extent of tissue damage. Pain may only occur after involvement of the periradicular tissues in the spread of infection.
Children are often unable to give accurate details of their symptoms, and the responses to clinical tests may be unreliable. Difficulties are frequently experienced in ascertaining the condition of the pulp from clinical findings.

Before commencing treatment

The majority of the following restorative procedures will require adequate local anaesthesia. In accordance with the biological principles established throughout this text, adequate isolation will also be necessary to prevent salivary contamination. A rubber dam should be placed, and isolation completed with cotton wool rolls and saliva ejector as seen in Figure 5.

Indirect pulp capping

The aim of this treatment is to maintain the vitality of the pulp in a deep carious lesion, when there is no direct pulpal involvement. All the carious dentine must be removed, and a thin layer of sound, non-carious dentine must remain. A lining of setting calcium hydroxide is placed, which stimulates the formation of secondary dentine. The tooth is restored over the dressing with a permanent restorative material.
It has been suggested that other medicaments may be used for indirect pulp caps, for example antibiotic pastes and anti-inflammatory drugs, but although some success has been reported, pulp necrosis and abscess formation often result without symptoms. As with the permanent dentition, research is presently focussing on the use of adhesive materials and bonding agents for indirect pulp capping. The long-term results of these long-term clinical trials are awaited.

Direct pulp capping

Fig, 5  A deciduous molar with a deep carious lesion has been isolated prior to commencing endodontic therapy.
This treatment is only recommended when a small traumatic exposure occurs, during cavity preparation of a vital non-infected pulp.
A calcium hydroxide dressing is placed directly over the pulp, followed by a lining and restoration, and the whole technique is carried out using local anaesthesia and with adequate isolation from salivary contamination. It has been suggested that the high cellular content of primary pulp tissue may be responsible for the failure of direct pulp capping in primary teeth.

Vital pulpotomy techniques

These techniques involve the removal of inflamed coronal pulp tissue and the application of a dressing to the radicular pulp in an attempt to either promote healing of, or fix, the upper portions, and to preserve the vitality of the apical tissue. Because of the difficulties involved in diagnosing the condition of the pulp tissue histologically before the commencement of treatment, careful assessment must be made at each stage of the procedure. Whenever the haemorrhage from the radicular pulp stumps is profuse and uncontrolled, the assumption is made that the inflammatory process has extended into the radicular tissue, and the therapy modified accordingly. There are three pulpotomy techniques.