Endodontic orthodontic ppt..final

ENDODONTIC ORTHODONTIC INTERRELATIONSHIP

Dr Bhagat S. TanwarPost graduate student

Dept. Conservative Dentistry & EndodonticsK.V.G.D.C Sullia

CONTENTS

• introduction• effect of orthodontics on the tooth being moved• Orthodontics as the Etiologic Agent for Endodontics • Endodontic intervention during orthodontic therapy• Endodontic intervention after orthodontic treatment• Influence of orthodontic treatment on viability of dental pulp• Effect of orthodontic movement on root resorption of endodontically treated teeth• Effect of orthodontic movement on traumatised teeth• Effect of orthodontic movement on surgically managed endodontically treated teeth• Effect of orthodontic therapy in influencing the final outcome of endodontic treatment• Regaining interproximal spaces• Conclusion• referrences

INTRODUCTION

• There is a paucity of information on the concise relationship between endodontics and orthodontics during treatment planning decisions.

• This relationship ranges from effects on the pulp from orthodontic treatment and the potential for resorption during tooth movement, to the clinical management of teeth requiring integrated endodontic and orthodontic treatment

EFFECT OF ORTHODONTICS ON THE TOOTH BEING MOVED

• Causes & effect of Orthodontic forces on pulp

• Orthodontic tooth movement can cause degenerative or inflammatory responses in the dental pulp of teeth with complete apical formation.

• The impact of the tooth movement on the pulp is focused primarily on the neurovascular system in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism.

Causes of pulp necrosis The common cause for pulp necrosis following orthodontic treatment

are following : Heavy continuous force : It causes undermining bone resorption leading to large increments of change and abrupt tooth movement resulting in severance of blood supply to the pulp

Distal tipping of incisor : Tipping movement to an extent that the root tip is actually moved outside the alveolar process can also cut off the blood supply to the pulp.

Heat generated by grinding during removal of ceramic brackets can cause pulp damage.

Labiolingual expansion appliance : The movement afforded by this technique resulted in a tipping motion in the apical third of the root causes lack of collateral circulation to the pulp which results in pulpal degenerations.

The pulpal changes appears to be more severe with greater orthodontic force. Effect of this nature may have a direct impact on the metabolism of the pulp tissue, in particular the odontoblasts in fully formed tooth and hertwig’s epithelial root sheath in incomplete formed teeth.

Alteration in pulpal vasculature with subsequent alteration in the metabolism of the pulpal cells results in increased deposition of reparative dentin along with concurrent increase in dystrophic mineralization.

Pulp is very resilient and has greater potential for healing. Only when all compensatory mechanisms fail the becomes necrotic which causes release of degrading proteins as tissue disintegrating by products.The compounds penetrate the tubules and discolor the surrounding dentin results in discoloration of tooth.

Evidence of pulp involvement are

Orthodontics as the Etiologic Agent for Endodontics

Some teeth require endodontic treatment as a result of

previous orthodontics. Because the action of the

blunting of root tips usually occurs in the area where the

apical blood vessels and nerves emerge, it can be seen

that injury at this susceptible site could affect pulp

vitality.

ORTHODONTIC FACTORS ASSOCIATED WITH NON VITALITY OF TEETH

TYPE OF MALOCCLUSION :

•Among different malocclusions, based on Angle’s classification system, studies have observed a

statistically significant difference between class I and class II div 1 malocclusion, with the latter

exhibiting more resorption.

EXTRACTION VS NON EXTRACTION :

•The analysis of literature reveals that both the extraction and the non extraction treatment have

the potential to produce damage, with the extraction therapy being potentially more detrimental.

•Among all the extraction patterns, extraction of all the first premolars showed the greatest

resorption potential.

Mechanotherapy Begg Vs edgewise :•Although previous studies could not find any significant resorption rate between

Begg light wire mechanics and edgewise ( Tweed ) techniques, a recent study by

McNab et al has reported a higher incidence of resorption, as well as amount of

root resorption in patients treated with the Begg appliance.

• They concluded that the incidence rate of root resorption was 3.72

times higher when extractions were performed as part of Begg

appliance therapy.

• Root resorption was also observed in all three stages of Begg

treatment, with the second stage exhibiting the least severity.

TYPE OF TOOTH MOVEMENT :

•Intrusion and torque movements are found to be most commonly associated

with the resorption process.

•This is evident when studying class II div 2 correction as well as Begg

mechanics.

•The intrusion performed in the first stage and the torquing in the third stage make the

Begg technique more vulnerable to resorption.

•The highest root resorption is reported to occur when 3 to 4.5 mm of torquing movement

was performed.

Length of treatment time

•The length of treatment time and root resorption have been positively correlated by

almost all studies.

•These studies have shown that increased treatment time makes tooth roots more prone to

iatrogenic response.

Type of force applied (Continuous vs

interrupted )•Interrupted forces were shown according to studies to cause less severe apical blunting and smaller resorption affected areas.

Tooth specificity:

•Evaluation of the vulnerability of specific teeth to the resorption process in the literature

has resulted in common agreement among authors that the maxillary incisors are the

teeth that are the most susceptible to the process.

•However, Controversy still exists regarding which incisors resorb the most: the centrals or

the laterals

•The majority of the studies published reported that the central incisors were more

susceptible to the process.

•Following the incisors in susceptibility to resorption in the maxillary arch are the

molars, followed by the canines.

•In the mandibular arch the most resorption vulnerable tooth is the canine, followed by

the lateral and central incisors.

•Among the posterior teeth, the most resorbed are the mandibular molars (with the distal

root exhibiting more resorption), followed by maxillary molars, mandibular premolars,

maxillary first premolars, and maxillary second premolars.

Root shape :•Various authors have evaluated abnormalities in root shape and its association to the

resorptive process.

•Among differently shaped root ends (normal, blunted, dilacerated, pipette shaped,

pointed, and incomplete), the least resorption was observed in blunted root ends and the

greatest was seen in pointed or tapered root ends.

•This phenomena is explained by the fact that the pressure from the axial component of

orthodontic forces is felt most at the root apex regions which are abnormal in shape. This results

in localized ischemic necrosis, which denudes the pericementum and cementoblasts, permitting

colonization of dentinoclasts.

•In comparison to the normal root shape, dilacerated roots show the most resorption followed by

pipette- shaped and the incomplete roots.

•Hence, any abnormal root shapes observed in the pre-treatment diagnostic records should be

observed with caution and should be monitored throughout the treatment period for any

iatrogenic damage.

Root length:

•A positive correlation is found between the root length and root resorption. The studies in

this regard report that longer roots are more prone than shorter ones to resorption.

•This may be due to the greater displacement required to produce an equal amount of torque,

versus shorter roots.

History of trauma:

•Previous history of trauma and the presence of pretreatment root resorption have been positively

correlated with root resorption seen after orthodontic treatment.

•Also studies have found a relationship between cortical plate proximity and increased root

resorption. All these findings point towards the importance of obtaining pretreatment diagnostic

records and proper evaluation. So that any risk elements can be identified and described.

Overjet or overbite:

•Studies to date have agreed with a positive correlation between an increase in overjet

and root resorption.

• The main reasons attributed to this phenomenon are the greater amount of torque and

greater root displacements required to correct excessive overjet.

Age, Gender and ethnicity: are they contributing factors?• Biologic factors such as age at the start of treatment and gender, have long been

associated with risk factors for the initiation of root resoption.

• Age at the start of the orthodontic treatment and incidence of root resorption have been

poorly correlated in almost all recent studies.

•Conflicting results have been seen when gender is considered. Various studies supported that

females are more prone to root resorption whereas various others stated that men were more

prone.

•The majority of the studies support a lack of correlation between gender and resorption.

•The relationship between ethnicity and root resorption was evaluated recently. The results

showed less severity among Asians in comparison to Caucasians and Hispanics

Endodontic intervention during orthodontic therapy

• The presence of ongoing orthodontic treatment may impact on the provision or endodontic treatment depending on a number of factors.

• From a diagnostic standpoint , radiographs may reflect osseous changes that may be misinterpreted as being of pulpal origin

• Full metallic bands may prevent an accurate response to electrical or thermal pulp testing , in addition to obscuring decay both radiographically and clinically

• Patient expresses symptoms that might be due to the orthodontic tooth movement or to an inflamed or degenerating pulp, thus making a differential diagnosis very difficult, especially if there has been a history of trauma.

• Also the presence of pulp calcifications may be due to both an inflamed degenerating pulp following trauma or to orthodontic tooth movement

• Tooth isolation for root canal treatment may also be compromised by the presence of orthodontic bands and wires

• Endodontic coronal access openings in teeth being moved orthodontically is usually not a problem in posterior teeth.

bishara & truelove 1990,krell et al 1993

• Working length determination in teeth actively undergoing tooth movement may also be challenging in the presence of apical resorption or even just root blunting in which there is no discrete apical constriction.

• The extent of the apical resorption can vary widely, with intrusive forces usually demonstrating a greater loss in length (mean 2.5 mm)

(Dermaut & DeMunck 1986).

Apical resorption usually destroys the natural constriction of the cemento-dentinal junction, resulting in a highly irregular, three-dimensionally rough, jagged, and notched root end. The periodontal ligament space is often widened and accentuated (Remington et al. 1989).

This will create difficulty in locating a biologically acceptable position at which to establish the working length.

• If the root end is wide open from the resorptive destruction, electronic apex locators are unreliable and of little clinical value.

• Therefore, the coronal-most point on the root above the resorbed apex which exhibits sound radiodensity must be identified.

• This position is used as the new radiographic apex and the working length is established 1.0± 2.0 mm coronal to that point

(Gutmann & Leonard 1995, Hovland & Dumsha 1997).

Endodontic intervention after orthodontic treatment

• Endodontically treated teeth can be moved orthodotically as readily as teeth with vital pulps

• Huettner & young 1955, Remington et al 1989, Spurrier et al 1990, hunter et al 1990, Mah et al 1996

• Because there is a risk of EARR (external apical root resorption) during the movement of any teeth, however , it is recommended that teeth requiring root canal treatment during orthodontic movement be initially cleaned and shaped followed by the interim placement of calcium hydroxide

• This should be maintained during the active phases of tooth movement, with the final canal obturation occurring upon completion of orthodontic treatment . This approach is not recommended when an already successful filling is in place prior to tooth movement.

Influence of orthodontic treatment on viability of dental pulp

• orthodontic tooth movement can cause degenerative and/or inflammatory responses in the dental pulp of teeth with completed apical formation.

• As early as 1936,Oppenheim demonstrated signs of pulpal degeneration in human teeth undergoing movement with fixed orthodontic appliances.

• He concluded that the lack of a collateral circulation for the pulp was the main etiologic factor behind this occurrence.

• The use of light intermittent forces to reduce the risk of damage to the dental tissues and to allow time for repair was recommended.

• Seltzer and Bender in 1984 explained that rapid orthodontic tooth movement increased the risk of pulpal injury, primarily due to alterations in the blood vessels in the apical periodontium and those entering the pulp.

• McDonald and Pitt Ford in 1994, using Laser Doppler flowmetry, assessed pulpal blood flow in permanent maxillary canines before, during and after application of a 50 gram force.

They found that changes in blood flow were dynamic in response to potentially poor perfusion of the tissues

• More at risk are teeth with mature apices and those with a history of trauma or significant caries.

• Pulpal respiratory rate was found to correspond to the degree of dentinogenic activity and pulpal metabolism.

• Age and apical opening size were the determining factors, with wide-open apices and young age correlating with a return to normal respiration.

• The impact of the tooth movement on the pulp is focused primarily on the neurovascular system, in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism.

• The responses induced in these pulps may impact on the initiation and perpetuation of apical root remodelling or resorption during tooth movement.

• The incidence and severity of these changes may be influenced by previous or ongoing insults to the dental pulp, such as trauma or caries.

Effect of orthodontic movement on root resorption of endodontically treated teeth

• According to the Glossary-Contemporary Terminology For Endodontics (1998), resorption is defined as `a condition associated with either a physiologic or a pathologic process resulting in a loss of dentine, cementum, and/or bone.

• Andreasen & Andreasen (1994) define the process further as being of three types;

• surface resorption, that is a self-limiting process, usually involving small areas followed by spontaneous repair from adjacent parts of the periodontal ligament in the form of new cementum.

• inflammatory resorption, where the initial root resorption has reached the dentinal tubules of an infected necrotic pulp or an infected leukocytic zone;

• replacement resorption, where bone replaces the resorbed tooth material that leads to ankylosis.

• The literature supports, but not conclusively, that teeth with previous root canal treatment exhibit less propensity for apical root resorption during orthodontic tooth movement

• Clinical observation that has addressed the role of neuropeptides in tooth movement, support the concept that minimal resorptive/remodelling changes occur apically in teeth that are well-cleaned , shaped and three – dimensionally obturated

• This outcome would depend on the absence of coronal leakage or other avenues for bacterial ingress.

• Other factor , such as specific root anatomical forms , may predispose to a greater incidence of resorption during movement.

In a literature review by Steadman, (1942) root canal treatment was criticized in that it was claimed that the devitalized root acts as a foreign body causing chronic irritation and root resorption. Histological sections of such resorptions showed cellular pictures typical of a foreign-body reaction. He considered that the resorption could not be controlled and therefore the prognosis for these teeth was unfavourable. Wickwire et al. (1974) revealed those teeth with root canal treatment moved as readily as teeth with vital pulps, but there appeared to be greater radiographic evidence of root resorption in the endodontically treated teeth when compared to the controls.

Literature supporting rct treated teeth and vital teeth undergo equal amount of resorption

• Huettner & Young (1955) challenged Steadman's theory and evaluated the root structure of monkey teeth with both vital and nonvital pulps (root canal treatment) following orthodontic movement.

• Histological examination showed no foreign-body reactions and the root resorption that was observed was similar in both the vital and devitalized teeth.

• Hunter et al 1990, Remington et al 1989 supported above concept

Sequlae of root resorption in rct treated teeth

1. The tooth may resorb, exfoliate, and the filling material may be removed with the tooth.

2. The tooth may resorb, exfoliate, and the filling material may be left in the bone. In these cases if the material is gutta-percha, a fibrous capsule will probably surround it. It is also possible that a sinus tract may form and the material will require removal.

3. In cases of both gutta-percha and silver cones,the extended material may undergo resorption itself after the tooth has undergone resorption and exfoliation.

4. In some cases the root may begin resorption, exposing the filling material, and subsequently the resorption ceases with the filling material protruding beyond the new apical foramen. In this situation the root is often seen to develop a new periodontal ligament space and lamina dura around the root apex in close approximation to the filling material.

5. In other cases, once the apical resorption begins, a radiolucency develops around the root apex and the filling material. A sinus tract may develop or there may be incidences of localized swelling. Likewise the tooth may remain symptom free and function normally.

Effect of orthodontic movement on traumatised teeth

• A traumatized tooth can be moved orthodontically with minimal risk of resorption, provided the pulp has not been severely compromised (infected or necrotic).

• If there is evidence of pulpal demise, appropriate endodontic management is necessary prior to orthodontic treatment.

• If a previously traumatized tooth exhibits resorption, there is a greater chance that orthodontic tooth movement will enhance the resorptive process.

• If a tooth has been severely traumatized (intrusive luxation/avulsion) there may be a greater incidence of resorption, with or without root canal treatment.

Effect of orthodontic movement on surgically managed endodontically treated teeth• As can be seen by the paucity of published literature and lack of information in dental

texts, very little is known about the ability to move successfully teeth that have undergone periradicular surgical procedures.

• greater amount of apical resorption due to the exposed dentine on the resected root face, irritation and persistent inflammation that may be caused by the root-end filling material, the adequacy of the seal achieved with the root-end filling material.

• Other factors to consider are the quality of the nonsurgical root canal obturation at the level of resection, the potential for exposed, contaminated dentinal tubules at the point of resection, and the potential for localized marginal periodontitis in those cases where a dehiscence or fenestration may be present.

• Low levels of success with surgical endodontics have been reported also in the absence of a sound buccal cortical plate of bone

(Hirsch et al. 1979, Skoglund & Persson 1985).

• Prompted the use of guided tissue regenerative procedures to enhance surgical outcomes

(Pecora et al. 1995, Rankow & Krasner 1996, Uchin 1996).

Baranowskyj (1969) in his study the rate of healing of the hard and soft alveolar tissues was assessed on teeth that had root fillings and previous periradicular surgeries, and that were subject to an early application of orthodontic intrusive forces.There was no visible attempt at bone regeneration in the surgical defect or at formation of a new periodontal ligament or cementum. The surgical defects were filled with degenerating blood clots and there was evidence of attempts at organization and infiltration with endothelial buds (angiogenesis)

The control group showed almost complete healing of all tissues. Histological assessment of both groups at 12 weeks indicated regeneration of bone and periodontal ligament was complete in the control and approximately two-thirds of the experimental group.

Effect of orthodontic therapy in influencing the final outcome of endodontic treatment

• The role of orthodontic tooth movement to optimise prognosis of endodontic therapy by improving access of the tooth for a good restoration . Mainly two types of tooth movements are appraised in literature in this perspective:

• Orthodontic extrusion

• Orthodontic uprighting

• The prime objective of tooth extrusion or forced eruption is to provide both a sound tissue margin for ultimate restoration and to create a periodontal environment (biologic width) that will be easy for the patient to maintain.

• Simon et al. (1980) indicated that extrusion of endodontically treated teeth did not present any apparent problems. They reported that the alveolar housing moves occlusally as the tooth is extruded followed by bone deposition at the alveolar crest and throughout the interradicular area, adjuncively crown lengthening can be done to improve esthetics

• Orthodontic uprighting is considered in posterior teeth in an attempt to augment embrasure space to aid in definitive post endodontic restoration. And it greatly improves endodontist access to perform treatment , therby helps in better treatment outcome

offers a method of treatment of teeth fractured close to the alveolar crest

exposes additional sound tooth structure & decreases the need for a surgical procedure later

also called:

• - controlled orthodontic extrusion

• - orthodontic eruption

• - vertical extrusion

• - assisted eruption

hithersay(1973) & ingber

Forced eruption

TOOTH MOVEMENT CAN BE OBTAINED WITH REMOVABLE OR FIXED ORTHODONTIC APPLIANCES

FORCED ERUPTION IS ADVOCATED FOR :

- TREATING TRANSVERSE ROOT FRACTURES & CORONAL FRACTURES

- ROOT CARIES

- EXTERNAL RESORPTIONS

- IATROGENIC PERFORATIONS

- AS AN ALTERNATIVE THERAPY FOR INFRABONY POCKETS

Application of force

THE TOOTH MUST BE STABILIZED TO ALLOW FOR REMODELLING OF THE PERIODONTAL APPARATUS & PREVENT RELAPSE

GENERALLY STABILIZATION IS FOR 4 WEEKS FOR EVERY MILLIMETER OF MOVEMENT

REGARDLESS OF TECHNIQUE, THE BIOLOGIC WIDTH SHOULD BE MAINTAINED

COMPLETING THE CASE INVOLVES FOLLOWING TRADITIONAL TECHNIQUES FOR POST & CORE FABRICATION AND CROWN PLACEMENT

Forced eruption

• TOOTH LACKING A CLINICAL CROWNo ENDODONTIC THERAPY IS COMPLETED IMMEDIATELY

o POST SPACE OF ADEQUATE WIDTH & LENGTH IS PROVIDED

o CONTROL OF GINGIVAL INFLAMMATION BY CURETTAGE IS COMPLETED PRIOR TO TOOTH MOVEMENT

o 0.030-TO-0.036 INCH S.S WIREHAVING A LOOP BEND IS FIT SNUGLY TO THE POST SPACE

TOOTH LACKING A CLINICAL CROWN

WIRE IS CEMENTED INTO THE CANAL WITH TEMPORARY CEMENT

DIRECT-BONDED ORTHODONTIC BRACKETS ARE PLACED ON A SUFFICIENT No. OF TEETH ON BOTH SIDES OF THE TOOTH TO BE ERUPTED FOR ADEQUATE ANCHORAGE

A RIGID 0.016 INCH WIRE IS LIGATED INTO THE BRACKETS, & AN ELASTIC LIGATURE CORD IS TIED FROM THE WIRE TO THE CEMENTED POST

THE TOOTH IS MOVED SLOWLY INTO POSITION OVER A PERIOD OF 4 TO 6 WEEKS

FORCED ERUPTION

FIXED DEVICES :

ORTHODONTIC BRACKETS ORTHODONTIC BRACKETS, BUTTON & ELASTIC

EMBEDDED ROD, ROOT HOOK & ELASTIC TEMPORARY BRIDGE, ROOT HOOK & ELASTIC

Removable appliances

EMBEDDED ROD IN ACRYLIC, ROOT HOOK & ELASTIC

HAWLEY DEVICEEMBEDDED SPRING, ROOT HOOK

EMBEDDED BUTTON, ROOT HOOK & ELASTIC

REGAINING INTERPROXIMAL SPACE Described by Reagan

• A long standing carious lesion on the proximal surface results in migration of adjacent teeth into the void created by the caries.

INDICATION

• A core or foundation restoration placed in the tooth requiring restoration

PROCEDURE

Tooth prepared for a full crown

• An acrylic crown fabricated, cemented and then an orthodontic separator inserted into the proximal space.

At subsequent appointment elastic is removed and a piece of 0.6mm brass wire threaded between the teeth apical to contact.

• The brass wire reapplied, as the tooth tipped, it may move upward into the occlusal plane, as it does, adjust occlusally to permit to continue to move

Then the full crown that will serve as the final restoration fabricated and cemented.

• CONCLUSION

A major percentage of orthodontic patients presents a problem in terms of root resorption during functional and esthetic benefits of the orthodontic treatment. It is recommended that periodical radiographic and careful clinical examination should be done for any incipient periapical lesions and to verify any unusual changes in pulp.

A combined endodontic – orthodontic therapy permits placement of a restoration that fulfills the periodontal and occlusal requirements of the tooth.

REFERRENCES

1.ENDODONTIC-ORTHODONTIC RELATIONSHIPS: A REVIEW OF INTEGRATED TREATMENT PLANNING CHALLENGES

International Endodontic Journal ’1999;32:343-3602.FORCED ERUPTION AFTER CROWN/ROOT FRACTURE WITH A SIMPLE

AND ESTHETIC METHOD USING THE FRACTURED CROWN Dental Traumatology ’2005;21:165-1693.RAPID FORCED ERUPTION: A CASE REPORT AND REVIEW OF FORCED

ERUPTION TECHNIQUES General Dentistry ’2004;March-April:167-1754.FORCED ERUPTION: REVIEW & CASE REPORTS General Dentistry ’2005;July-August:274-277