causes and mangment of post endodontic disease

Praveen Jangid.

Causes and management of post treatment

endodontic disease

1

Introduction

In recent years the number of people seeking endodontic

treatment has dramatically increased because of conservative

tendency towards root canal treatment over tooth extraction

(Ruddle 2002)

The aim of root canal treatment is to clean and disinfect the root

canal system in order to reduce the number of micro-organisms,

remove necrotic tissue, and finally seal the system to prevent

recontamination.

Success rates up to 97% have been reported for endodontic

initial treatment (Friedman 2004)

2

Prevalence of apical periodontitis and other post-treatment

periradicular diseases can exceed 30% of all root-filled teeth.

(Boucher 2002; Eriksen 2002; Friedman 2002; Dugas 2003)

In the past, undesirable outcomes of endodontic therapy were

described as failures.

Friedman states that “most patients can relate to the concept of

disease-treatment-healing, whereas failure, apart from being a

negative and relative term, does not imply the necessity to pursue

treatment.”

He has suggested using the term posttreatment disease to describe

those cases that would previously have been referred to as treatment

failures.

Principles and practice of endodontics, ed 4, St. Louis, 2009.

3

Post-treatment apical periodontitis,

which can be categorised as-

B Dent J.; 2014;216 (6); 305-311

• If developed after treatment

Emergent

• If persisted despite treatment

Persistent

• If developed after having healed

Recurrent

4

Etiology of Post treatment Disease

To effectively plan treatment, the clinician may place the

etiologic factors into four groups

1) Persistent or reintroduced intraradicular microorganisms

2) Extraradicular infection

3) Foreign body reaction

4) True cysts

Essential Endodontology.Prevention and treatment of apical

periodontitis, New York, 2008,5

Causes of post-treatment apical periodontitis

Microbial cause – intraradicular infection

Microbial cause – extraradicular infection

Non-microbial cause

Procedural errors and

6

Microbial cause – intraradicular infection

Highly associated with intraradicular infection by studies using

microscopy, culture or molecular methods.

J Endod 2009; 35: 169–174.

Bacteria resisting the effects of treatment usually located in areas

of difficult access, to instruments and irrigants, and often in

direct contact with a source of nutrients from the periradicular

tissues.

Include the

Apical part of the root canal,

Lateral canals,

Apical ramifications,

Isthmuses

Dentinal tubules.7

Microbial cause – intraradicular infection…..

Akehashi et al. (1965) exposed the dental pulps of conventional and germ-free rats to the oral cavity and reported that pulp necrosis and periradicular lesions developed only in conventional rats with an oral microbiota.

Sundqvist (1976) confirmed the important role of bacteria in periradicular lesions in a study using human teeth, in which bacteria were only found in root canals of pulpless teeth with periradicular bone destruction.

The chances of a favourable outcome with root canal treatment are significantly higher if infection is eradicated effectively before the root canal system is obturated.

However, if microorganisms persist in the root canal at the time of root filling or if they penetrate into the canal after filling, there is a higher risk that the treatment will fail (Byström et al. 1987, Sjögren et al.1997).

8

Risk of reinfection will be is dependent on the quality of the root

filling and the coronal seal (Saunders & Saunders 1994).

A radiograph of a seemingly well-treated root canal does not

necessarily ensure the complete cleanliness and/or filling of the

root canal system (Kersten et al . 1987).

To survive in the root-filled canal, microorganisms must

withstand intracanal disinfecting measures and adapt to an

environment in which there are few available nutrients.


9

Bacteria entombed by the root filling usually die or are prevented from gaining access to the periradicular tissues.

Some bacterial species will probably survive for relatively long periods, deriving residues of nutrients from tissue remnants and dead cells.

If the root canal filling fails to provide a complete seal, seepage of tissue fluids can provide substrate for bacterial growth.

If growing bacteria reach a significant number and gain access to the periradicular lesion, they can continue to inflame the periradicular tissues.


10

Several regulatory systems play essential roles in the ability of

bacteria to withstand nutrient depletion.

These systems are under the control of determined genes, whose

transcription is activated under conditions of starvation.

Under conditions of nitrogen starvation, the activation of the

Ntr gene system enables bacteria that require ammonia as a

nitrogen source to scavenge even small traces of ammonia.

Under high concentration of ammonia, the Ntr gene system is

uncoupled.

Int Endod J 2001; 34, 1–10.


11

Some facultative bacteria may activate the Arc system

(aerobic respiration regulatory ), under conditions of low

concentrations of molecular oxygen.

So that a shift can occur from aerobic to anaerobic

metabolism.

Under low concentrations of glucose, some bacteria can

activate the catabolite repressor system, under control of the

genes Cya (adenylate cyclase) and Crp (catabolite repressor

protein), which induce the synthesis of enzymes for the

utilization of various other organic carbon sources.


12

Under conditions of phosphate starvation triggered by low

concentrations of inorganic phosphate, cells turn on genes for

utilization of organic phosphate compounds and for the

scavenging of trace amounts of inorganic phosphate.

Int Endod J 2001; 34, 1–10.

Heat-shock proteins are family of highly conserved proteins

whose main role is to allow microorganism to survive under

stressful conditions.


13

The microbiota associated with failed cases differs markedly

from that reported in untreated teeth (primary root canal

infection).

T.denticola, P.alactolyticus, T.forsythia, P.gingivalis, T.

socranskii, P.endodontalis.

Fungi are not found.

The reduction of Gram-negative organisms following endodontic

treatment and the subsequent proportional increase of Gram-

positives facultatives.

Streptococci ( Streptococcus mitis, Streptocoocus gordonii,

streptococcus anginosus, Streptococcus sanguinis and

streptococuus oralis), Parvimonas micra, Actinomyces species,

Propionobacter species, Pseudoramibacter alactolyticus,

lactobacilli, E faecalis.


JOE 2008; 34(11), 129614


15

Möller (1966), reported a mean of 1.6 bacterial species per root

canal. Anaerobic bacteria corresponded to 51% of the isolates.

Enterococcus faecalis was found in 29% of the cases.

E. faecalis strains have been demonstrated to be extremely

resistant to several medicaments, including calcium hydroxide

(Jett et al . 1994, Siqueira & Uzeda 1996, Siqueira & Lopes 1999).

It has been shown that some bacteria, such as E. faecalis, can

enter a viable but noncultivable state, which is a survival

mechanism adopted by many bacteria when exposed to

environmental stresses like low nutrients concentrations, high

salinity, and extreme pH


16

Sedgley et al showed that E. faecalis has the capacity to recover

from prolonged starvation state in the root canal treated teeth;

when inoculated into the canals, this bacterium maintain viability

for 12 months without additional nutrients.

Thus viable E. faecalis entombed at the time of root canal filling

may provide a long term nidus for subsequent infection.

Yeast-like microorganisms have also been found in root canals of

obturated teeth in which treatment has failed (Nair et al. 1990a).

In fact, it has been demonstrated that Candida spp. are resistant

to some medicaments commonly used in endodontics (Waltimo

et al . 1999).


17

Persistent infections are the major cause of post-treatment apical

periodontitis does not preclude secondary infections due to

coronal leakage.

Cross-sectional studies indicate that the best outcome is achieved

in teeth with adequate root canal fillings associated with

adequate coronal restorations.

J Endod 2013; 39: 600–604.

It is advisable to treat the tooth as a continuum, placing a well-

adapted permanent coronal restoration as soon as possible after

finishing root canal treatment.


18

Microbial cause – extraradicular infection

Extraradicular infection may be associated with chronic inflammation and lead to endodontic treatment failure.

By defending themselves against the action of the complement system, avoiding destruction by phagocytes, causing immunosuppression, changing antigenic coats, and inducing proteolysis of antibody molecules (Siqueira 1997).

Int Endod J, 2001; 34, 1–10,

May be associated with –A biofilm formation on the external root surface

Endod Dent Traumatol 1990; 6: 73–77.

Sometimes showing calculus-like calcifications,

Int Endod J 2005; 38: 262–271.

or forming cohesive actinomycotic colonies within the body of the lesion.

Endod Dent Traumatol 1986; 2: 205–209.

19

The extraradicular infectious process can be dependent on or

independent of the intraradicular infection.

Dependent infection- maintained by constant proliferation and

invasion of the periradicular tissues by bacteria present in the

intraradicular infection.

Cannot sustain itself without the intraradicular component.

Independent infections - that are no longer fostered by an

intraradicular infection and as such may not respond to adequate

root canal treatment.

Endodontic Topics 2003; 6: 78–95.

Microbial cause – extraradicular infection…..

20

One of the most significant mechanisms of evasion from

the host defence system is the microbial arrangement in a

biofilm.

A biofilm can be defined as a microbial population attached to an

organic or inorganic substrate, surrounded by microbial

extracellular products, which form an intermicrobial matrix

(Costerton et al )

Biofilm formation is a step-wise procedure ,its formation occurs

in the presence of microorganisms, fluid and solid surface.


21

Organized in biofilms, microorganisms show higher resistance to

both antimicrobial agents and host defence mechanisms when

compared with planktonic cells.

(Costerton et al 1987, 1994, Gilbert et al. 1997).

By examining teeth refractory to root canal treatment, Tronstad

et al. (1990) reported the occurrence of bacterial biofilms

adjacent to the apical foramen and bacterial colonies located

inside periradicular granulomas.

Int Endod J, 2001; 34, 1–10.


22

The major consideration regarding treatment of periradicular

biofilms is that the clinician cannot detect a biofilm in any

particular clinical case.

Theoretically, microbiological sample could inform the clinician

if the root canal is bacteria free or if there are persistent

intracanal microorganisms.

Once root canal samples yield negative cultures, the canal is

obturated. If subsequent healing does not occur, then one may

suspect extraradicular infection.

It is well known that intracanal disinfection procedures or

systemically administrated antibiotics can not easily affect

bacteria located outside the apical foramen.


23

The placement of endodontic medicaments into the periradicular

tissues in order to eliminate microorganisms and to decompose

periradicular biofilms does not appear to be an adequate

procedure.

First, it is currently difficult or even impossible to clinically

diagnose extraradicular infections.

Secondly, most endodontic medicaments are cytotoxic and/or

may have their antimicrobial effects neutralized after apical

extrusion.

The development of a nonsurgical strategy to combat biofilms

appears questionable.

Therefore, extraradicular infections, if present, must be treated

by means of periradicular surgery.


24

So far, there is no clear evidence that an extraradicular infection

can exist as a self-sustained process independent of the

intraradicular infection.

J Endod 2008; 34: 1124–1129

Ricucci et al. evaluated several treated teeth with post-treatment

apical periodontitis and could not detect any case of independent

extraradicular infection.

J Endod 2009; 35: 493–502.


25

Sjogren’s study on Success vs. Failures

Sjögren and his associates - study of 356 endodontic patients, re-

examined 8 to 10 years later

Reported a 96% success rate if the teeth had vital pulps prior to

treatment.

The success rate dropped to 86% if the pulps were necrotic with

periradicular lesions.

They dropped still lower to 62% if the teeth had been re-treated.

They concluded by stating that “teeth with pulp necrosis and

periradicular lesions and those with periradicular lesions

undergoing re-treatment constitute major therapeutic problems…

J Endod 1990;16:498–504

26

Clinician Versus Bacteria

What treatment does What bacteria do to survive

Mechanical effect (irrigants) form biofilm firmly adhere to canal

wall

colonizes in isthmus, ramifications

and dentinal tubules.

Mechanical effect (instruments) ----as above

Chemical effect ( irrigants) -----as above Plus they are protected

by

tissue remnants, dentin, serum or

dead cells, all of which have

activity to reduce effect of

intracanal medicament.

JOE 2008; 34(11), 129627

What treatment does What bacteria do to survive

Chemical effect ( interappointment

dressings)

resistant to antimicrobial T/t,

Form biofilm structures

enclosed by protective

polysaccharide matrix.

Ecological effect : ( nutrient

deprivation)

Turning on several genes

Enter viable noncultivable state.

Forms new pair and partnership.

JOE 2008; 34(11), 129628

Non-microbial cause – fact or myth?

There are few case reports that suggest that some lesions may not

heal because of endogenous or exogenous non-microbial factors.

Crit Rev Oral Biol Med 2004; 15: 348–381.

Endogenous causes include cholesterol crystals and true cysts,

Exogenous causes comprise foreign-body reactions to apically

extruded filling materials, paper points or food.

J Endod 2009; 35: 493–502.

In most of these cases it is very difficult to rule out the

concomitant presence of infection as the cause of disease.

Therefore, the participation of non-microbial factors as the

exclusive cause of treatment failure has still to be consistently

proven.

29

Although in the past the toxicity of the root filling materials had

been considered as the cause of persistent inflammation when

apically extruded.

Arch Oral Biol 1966; 11: 373–383.

apical extent of root canal fillings seems to have no correlation

with treatment failure, provided infection is absent.

Int Endod J 1997; 30: 297–306.

Disease associated with overfilled root canals is generally caused

by a

Concomitant infection in cases where a proper apical seal is missing,

Favouring nutrient supply to residual bacteria in the canal,

or when infected dentinal debris are projected extraradicularly as a

result of previous overinstrumentation.

B Dent J.; 2014;216 (6); 305-311

30

Procedural errors and post-treatment disease

The major problem with a procedural accident arising during

chemomechanical procedures is when it prevents or makes it

difficult for the clinician to properly disinfect the apical part of

the root canal.

Such as-

Missing canal,

Fractured instrument,

Ledge

Perforation

Overfilling

31

Management of post-treatment apical

periodontitis

Teeth with post-treatment apical periodontitis can be managed

by either nonsurgical endodontic retreatment or periradicular

surgery, some teeth are extracted, but many remain untreated in

spite of the evident pathosis.

These two approaches differ significantly in rationale –

retreatment is an attempt to eliminate root canal infection,

whereas apical surgery is an attempt to enclose the infection within

the canal.

To foster confidence and appropriate management, definitive

criteria are required to select cases for extraction, retreatment or

apical surgery

32

Considerations are unique to retreatment cases

(i) An extensive restoration may have to be sacrificed and remade;

(ii) Potential for future disease may have to be considered ;

(iii) Morphologic alterations resulting from the previous treatment

may present unusual technical and therapeutic challenges ;

(iv)The healing rate is generally lower than after initial treatment.

because of greater difficulty in eliminating the infection ;

(v) Patients may be more apprehensive than with the "routine“

initial treatment.

The above considerations complicate the subjective process of

case selection

J. O. E. 1986; 12: 28-33.

33

Case Selection

Diagnosis.

Presence or absence of disease is determined according to

clinical and radiographic findings.

Assessment of outcome of root canal treatment

Should be assessed at least after 1 year and subsequently as

required.

Favorable outcome:

Absence of pain, swelling and other symptoms, no sinus tract,

no loss of function.

Radiological- normal periodontal ligament space around the

root.

Quality guidelines European Society of Endodontology

IEJ,39, 921–930, 200634

Uncertain outcome:

lesion has remained the same size or has only diminished in size.

In this situation it is advised to assess the lesion further until it

has resolved or for a minimum period of 4 years.

If a lesion persists after4 years the root canal treatment is usually

considered to be associated with post-treatment disease.

Unfavorable outcome:

1) The tooth is associated with signs and symptoms of Infection.

2) A radiologically visible lesion has appeared subsequent to

treatment or a pre-existing lesion has increased in size.

3) A lesion has remained the same size or has only diminished in

size during the 4-year assessment period.

4) Signs of continuing root resorption are present.

In these situations it is advised that the tooth requires further

treatment.

IEJ,39, 921–930, 200635

Non-endodontic disease or a healing process should be carefully

considered as a differential diagnosis .

The case history is reviewed,

Noting previous radiographs when available.

Past symptoms.

Time elapsed since previous treatment and

Previous attempts at retreatment or apical surgery

36

In the past, it was the clinician's responsibility to select and

then provide the most appropriate treatment.

Currently, it is the patient who selects the treatment.

The clinician's responsibility is to communicate the

information and thus facilitate the patient's decision making

process, and to provide the selected treatment.

37

Patient Considerations

People's attitudes towards disease and necessity of treatment

differ significantly

Int Endodod J 1998: 31: 358-63.

38

Tooth Considerations

Site of infection-

For root canal infection prognosis is best with retreatment.

For periapical (extraradicular) infection independent of the root

canal flora, prognosis is best with apical surgery.

In contrast, when a vertical crack or fracture is present, prognosis is

hopeless with both procedures .

Differential diagnosis is required, therefore, to establish the likely

site of infection.

Typical manifestation of periapical actinomycosis - one or more

sinus tracts, and that of vertical crack/ fracture - isolated, narrow

defect along the root

39

Root canal complexities

The potential of retreatment to

capacitate healing is actualised mainly

when root canal patency can be regained

throughout.

Feasibility of overcoming these

complexities must be assessed.

40

Perforation

Perforation of the pulp chamber or root comprises a pathway of

infection and impairs the prognosis.

Retreatment in conjunction with internal repair of the perforation

is warranted to curtail the infection.

when healing appears unlikely or does not occur, surgery may be

required, including external repair of the perforation and

possibly an attempt at guided tissue regeneration.

Restorative, periodontal and aesthetic factors.

Teeth considered to have hopeless restorative or periodontal

prognosis should be extracted.

With compromised periodontal support, surgery may result in an

unfavourable crown-root ratio; therefore, retreatment is selected.

41

Clinician considerations

Clinicians vary with regards to-

Capability- Procedure that can be performed best by the

attending clinician is selected,

Armamentarium- The instruments required to perform either

procedure are available, that procedure is selected.

Time availability- In specific circumstances (remote areas,

community clinics) an excessive practice load prevents a

clinician from undertaking a lengthy retreatment of one complex

case, surgery is selected

42

Previous Treatment Attempts

If a previous retreatment or apical surgery procedure did not

result in healing, the quality of the treatment provided should be

accessed.

If it is considered that the initial case selection was appropriate

but the quality can be significantly improved, the same

procedure is selected again.

Otherwise, the alternative procedure is selected, considering that

it may better address the site of the infection and capacitate

healing

43

Prevention of potential disease

Endodontically treated teeth may appear to be free of any signs

of disease and yet harbor microorganisms in the canal.

The factors that may affect emergence of post-treatment

endodontic disease are listed below:

The adequacy of the coronal seal;

The adequacy of the root filling

The need for a new restoration

Endodontic Topics 2002, 1, 54–7844

When both the root filling and the coronal seal are suspect, and a

new restoration is needed.

In these cases retreatment is indicated, as it offers the benefit of

preventing post treatment disease.

When a new restoration is not needed and only the root filling is

suspect, emergence of post-treatment disease is less likely, and

retreatment offers a lesser or no benefit.

In these cases only follow-up is indicated; retreatment, and

associated possible complications, can be avoided.

Endodontic Topics 2002, 1, 54–7845

Endodontically treated tooth

Evaluation of treatment results

Established failure Potential failure

Feasibility of coronal access

unfeasible

Surgery

Feasible

Retreatment new restoration

Evaluation of obturation quality

Satisfactory

Follow up

Unsatisfactory

Needs new restoration

Follow up

Needed Not needed

46

Outcome of endodontic retreatment

success rate of retreatment as revealed by well-controlled studies

ranges from 62% to 84%.

J Endod 2004;30: 745–50

The approximately 10-20% lower success rate to be related to

the following:

Inability of completely removing the previous obturation or

Correcting previous errors, which may limit access to residual

bacteria;

Difficulties to reach persistent bacteria located in areas distant

from the main root canal; and

Resistance of persistent bacteria to the antimicrobials used.

47

Outcome of periradicular surgery

Teeth that had previous root canal obturation categorised as

inadequate, presents a significantly better outcome than well-

treated teeth.

J Endod 2004; 30: 627–633.

Inadequately treated teeth may not respond so well to

retreatment, periradicular surgery may then arise as a good

therapeutic alternative.

Studies have reported a high success rate for surgery (87%-92%)

when performed using magnification, ultrasonic root-end

preparation, and root-end fillings with materials such as mineral

trioxide aggregate (MTA), intermediate restorative material

(IRM) or Super ethoxy benzoic acid (SuperEBA).

Int Endod J 2003; 36: 520–526. 48

Rubinstein and Kim reported a 91.5% success rate over 5–7 years. These percentages are significantly better than those quoted in the earlier studies of endodontic periapical surgery

Int Endod J 2003; 36: 193–8

In summary, the best success rate can be achieved if orthograde retreatment is done first followed by periapical surgery, if indicated.

49

Nonsurgical Vs surgical retreatment

At the 1-year follow up the success rate for surgical treatment was

slightly better than non-surgical.

When the follow up was extended to 4 years the outcome for the two

procedures became similar.

Cochrane Database Syst Rev. 2007 Jul 18;(3):CD00551150

Interestingly, the percentage of teeth still in ‘function’ ranged from 78% to 97%. This is a similar term to ‘implant survival’ which many implant studies have used as a measure of implant treatment outcomes.

The survival rate of dental implants has been reported as ranging from 76% to 94% ‘Survival’ or ‘functional’, however, do not necessarily equate to biological success.

Clin Oral Implants Res 2004; 15: 8–17

51

Conclusion

The main aim of root canal treatment is to clean and disinfect the root

canal system, thereby reducing the bacterial load, removing necrotic

tissue and creating an environment in which periapical healing can

occur.

Identify the possible causes of post-treatment apical periodontitis and

approach these cases accordingly.

Nonsurgical retreatment is considered to provide a better opportunity to

disinfect the root canal system than a surgical approach, as it is

generally not possible to clean the coronal part of the root canal system

during endodontic surgery.

The best success rate can be achieved if orthograde retreatment is done

first followed by periapical surgery, if indicated.

52

Thank you

53

causes and mangment of post endodontic disease

Health & Medicine