sealbio a novel non obturation endodontic treatment based on concept of regeneration

E-mail: naseemys@gmail.com Date of submission : 07.04.2012 Review completed : 16.06.2012 Date of acceptance : 19.07.2012 SealBio: A novel, non-obturation endodontic treatment based on c

Address for correspondence:

Dr Naseem Shah, Department of Conservative Dentistry

and Endodontics and Chief, Centre for Dental Education and

Research, All India Institute of Medical Sciences,

New Delhi- 110 029, India.

E-mail: naseemys@gmail.com

Date of submission : 07.04.2012

Review completed : 16.06.2012

Date of acceptance : 19.07.2012

SealBio: A novel, non-obturation endodontic

treatment based on concept of regeneration

Naseem Shah, Ajay Logani

Department of Conservative Dentistry and Endodontics and Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India

A b s t r a c t

Introduction

Introduction: “SealBio”, an innovative, non-surgical endodontic treatment protocol, based on “regenerative concept” has been developed to manage pulp and periapically involved teeth

Materials and Methods

Materials and Methods: Subsequent to Institute’s ethical clearance, 18 patients presenting with signs and symptoms of pulp and periapical disease were included in the study (11/M, 7/F; Mean age - 44.7 years; range 15-76 years) The protocol included a modified cleaning and shaping technique involving apical clearing and foramen widening, combined with inducing bleeding and clot formation in the apical region Calcium-sulphate based cement was condensed with hand pluggers into the canal orifices An appropriate permanent restoration was given The patients were followed-up clinically and radiographically

at regular interval of 6 months Six teeth in 3 patients were also evaluated pre and post treatment CBCT at 6-months

Results

Results: The novel treatment protocol was found to be favourable in resolving periapical infection, both clinically and radiographically

Conclusions

Conclusions: This innovative endodontic treatment protocol highlights and reiterates the importance of cleaning and shaping and puts forth the possible role of stem cells and growth factors in healing after non-surgical endodontic therapy

Keywords: CBCT; non-obturation Endodontic treatment; periapical healing; regenerative endodontics; sealBio

INTRODUCTION

One of the essential requisites for successful outcome of

endodontic treatment is believed to be achieving sealing

of root canal system at both; apical and coronal end of a

disinfected root canal Even with conventional guttapercha

obturation, the ultimate aim is to achieve a cemental/

fibrous barrier at the root apex.[1] Therefore, achieving

a biological seal, “SealBio” should be preferable over an

artificial barrier of sealer and guttapercha cones at the

apical end of root canal system

With the success achieved with “revascularization” in

healing of periapical lesions and hard tissue deposition at

apical and lateral walls of the root canals (maturogenesis)

in immature teeth,[2-4] the processes involved in the healing

mechanism are now better understood Role of various

stem cells, growth factors, Hertwig’s epithelial root sheath

(HERS) and their interactions in regeneration of tissues

have been documented.[5]

Exploiting this mechanism of stimulating healing and regeneration of tissues and combining it with thorough disinfection of root canal system, a novel treatment approach was conceived to manage non-vital mature teeth with periapical pathology

MATERIALS AND METHODS

Institutional ethical clearance was obtained Eighteen cases of pulp and periapical infection, irrespective of age, gender or the tooth involved were included in the study (11 males, 7 females; age range, 15-76 years; mean age, 44.7 years) The cases presented with acute or chronic apical abscess, with or without radiographic evidence of periapical pathology

After written informed consent of the patient, access opening, cleaning and shaping of root canals by crown-down technique was done The canals were copiously irrigated with 2.5% sodium hypochlorite Depending on the

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DOI:

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extent of infection; either one or two inter-appointment

dressing of triple antibiotic paste of metrogyl, ciprofloxacin

and tetracycline was given Special attention was given

to apical third cleaning Apical patency was maintained

throughout the cleaning and shaping procedure The apical

third of the canal was debrided by “apical clearing” which

involved its enlargement with 2-4 file sizes larger than the

master apical file (MAF) at working length and removal of

loose debris from the apical region.[6] Subsequent to this

“apical foramen widening” was done with larger K-files

used sequentially till size 25-30 to clean the cemental part

of the canals When the infection control was achieved,

as evident from a clinically symptom-free tooth, healed

swelling or sinuses, a final wash with an anti-microbial

solution was done and the canals were dried After

checking the patency, determined by smooth passage

of # 15 ISO instrument, intentional over-instrumentation

into periapical region was done with #20 K-file to induce

bleeding near the apical foramen The file was gently given

2-3 clock-wise turns and then withdrawn by giving

counter-clockwise rotation A calcium sulphate-based cement

(Cavit) was introduced in the access cavity and with a hand

plugger, condensed into the cervical third of root canals

A suitable coronal restoration was given Immediate

post-treatment radiograph was taken The patient was recalled

every 6-months for clinical and radiographic evaluation

Pre and post treatment CBCT was done for six teeth in 3

cases who volunteered to undergo CBCT evaluation All the

cases were done on a single iCAT machine at 120 kvp, 5

mA with an exposure time of 7 seconds and voxel size of

0.25 The parameters evaluated were: lesion size, bone and

cementum density in HU and periapical index (CBCT-PAI)

RESULTS

All the 18 cases treated by this novel endodontic treatment

protocol showed very good response; both clinically as well

as radiographically Follow-up of 3 years was completed

for 5 cases, 2 ½ years for 5 cases,;2 years for 5 cases and

6-months for 3 cases [Figures 1 and 2] The soft tissue

healing was excellent; intraoral sinus, buccal soft tissue

swelling and bone expansion had completely resolved

in all the cases On radiographic examination, complete

resolution or decrease in the size of periapical lesion was

evident In two cases of endo-perio lesion, marked healing

of the periodontal defect was also seen The CBCT findings

are shown in Table 1 Remarkable decrease in the lesion size

(CBCT-PAI) and increase in bone and cementum density {in

Hounsfield unit (HU)} were documented [Figures 3 and 4]

DISCUSSION

The basis for success of endodontic treatment is to remove

the cause, i.e all necrotic debris, bacteria and their

by products As early as in 1939, it was known that the

root canal was the seat of infection.[7] After debridement

and disinfection of root canals, peri-radicular lesion had healed even without obturation of root canal.[8] Dubrow[9]

in 1976 had argued that often treatment failures that were attributed to poor obturation could be the result of improper debridement He also suggested that if canals were thoroughly debrided, healing of periapical tissues would occur and tissue fluid may not enter the canal space, even if it was not obturated Dass[10] commenting

on calcium hydroxide apexification had also stated that

“perhaps filling is unessential and mere eradication of infection may be sufficient for apexification.” Role of thorough canal debridement and disinfection in periapical healing with incomplete obturation of root canals has been reported [11] In an experimental animal study on dog’s teeth reported in 2006, it was documented that there was no difference in healing of apical periodontitis with and without obturation, if root canals were thoroughly instrumented and debrided [12]

In the recent past, the new treatment method of inducing revascularization in non-vital immature teeth has shown very encouraging results.[2-4] The present study was planned

to determine whether a novel, non-surgical treatment protocol, based on regenerative principles, can be effective

in fully mature teeth with pulp and periapical infection The argument given for complete 3-diemensional, fluid tight seal of the entire root canal system is that it will entomb the remaining microbes and also will not permit or

at least delay the microbial infiltration, if there was leakage from the coronal restoration.[13] However, even after complete obturation, if coronal seal is broken for more than

Figure 1: (a) A 53-year-old man presented with discrete soft

tissue swellings at gingival margin in relation to # 47 (b) Sinus tract traced with guttapercha point documenting a pulpo-periodontal lesion Note the bone loss on mesial aspect of mesial root (c) Follow up X-ray at 6 months showing healing

of periodontal defect (d) At 3-years, complete healing and new bone regeneration in inter dental area between #46 and

#47 is evident

a

c

b

d

Table 1: Showing result of CBCT evaluation of 6 teeth in 3 cases

Initial Follow-up Initial Follow-up Initial Follow-up Initial Follow-up

Figure 2: (a) Immediate post-treatment X-ray showing diffuse radiolucency around distal root in a 40-year-old man (b) Just

6-weeks after the treatment, remarkable healing of the lesion is seen (c) One-year follow-up x-ray showing complete healing

Figure 3: CBCT scan (i) & (ii) showing the pre and 6-months

post treatment result Figure 4: CBCT scan (i) & (ii) showing the pre and 6-months post treatment result

3-4 weeks, it is recommended to perform retreatment, as

during this period, bacteria would have colonized the pulp

space and the tooth would develop endodontic infection

sooner or later.[14]

Grossman in 1953 had stated that an optimal concentration

of necrotic debris or toxic load is necessary to sustain or

increase the periapical lesion.[15] It has also been concluded

based on clinical and experimental animal studies that

stagnant tissue fluid and sterile necrotic pulp tissue do not

sustain inflammation at the periapex.[16]

Fabricius[17] had stated that permanent root canal filling,

per se, had a limited effect on the outcome of endodontic

treatment, if bacterial load was not controlled at the time

of obturation This exhaustive animal study adequately underlined the importance of thorough disinfection of canals rather than depend on high quality obturation for favorable outcome of endodontic treatment

Siqueria[18] put forth the argument that for any species to cause disease, they have to reach a population density (load) conducive to cause tissue damage, either directly

or by host tissue response to infection Hence, clinically

it is essential to reduce bacterial load to levels below that detected by culture procedures, i.e.103-104 cells The treatment protocols should be so standardized that the bacterial count is brought to below this known threshold

as compared to glass ionomer cement or mineral trioxide aggregate Care was exercised in planning and placement

of coronal restoration

Although it has been suggested that reversal of healing process after non-surgical endodontic treatment is uncommon[26] and hence prolonged follow-up of cases showing healing may not be necessary.[27] Nevertheless,

in the present study, a maximum follow-up of three years was possible and the cases are planned to be followed-up further

The role of CBCT in evaluation of periapical healing has been reported.[28] It provides objective, non-invasive method to measure periapical healing and mineralized tissue deposition CBCT evaluation of six teeth showed increased density of bone and cementum, supporting the hypothesis that mineralized barrier following this novel technique does take place

Metzger Z and Abramowitz[29, 30] reflecting on philosophy of

endodontic treatment commented that “cleaning, shaping

and preventing bacterial stimulation at root apices was taking

a simplistic and mechanistic view Endodontics should not limit itself to only better ways of cleaning, shaping and obturation New concepts and methods, based on biological concepts must supplement traditional ones” Tronstad also suggested

the possibility of “Biological Obturation Technique”

in future The present innovative technique utilizing modified cleaning and shaping technique combined with regenerative, tissue engineering principles for treatment of infected, non-vital mature teeth is a step in this direction Further well-planned experimental animal studies can provide information on type of cells involved and tissue deposited The evidence generated from this case-series also questions the role of obturation in non-surgical endodontic treatment However, again, more evidence would need to be generated in the form of a randomized clinical trial to evaluate the role of obturation in view of recent advances in disinfection protocols, techniques and restorative materials

CONCLUSION

The new technique, as discussed and documented in this pilot clinical study can prove to be the most simple, easy

to perform and cost-effective method of regenerative endodontic treatment The result proves the importance

of thorough cleaning and shaping and a well-condensed, bacteria-tight coronal seal in endodontic treatment success

A small sub-set of six teeth evaluated by pre and post treatment CBCT has shown increased density of bone and cementum, supporting the premise that mineralized tissue deposition does occur at the root apex (hence sealing the apical end with biological tissue, i.e SealBio)

In the present study, heavy stress was laid on thorough

disinfection of canal space and tight coronal seal Special

care was taken to clean the apical third of the canal

space Apical clearing, apical foramen widening and

over-instrumentation into periapical region were done to induce

bleeding near apical foramen It is hypothesized that the

clot formed provides a scaffold into which locally residing

stem cells can get seeded and the cascade of healing

process can initiate

“Apical clearing” is a technique described to remove loose

debris from the apical region by widening the apical canal

with instruments 2-4 sizes larger than the master apical file

(MAF) used at radiographic terminus without transportation

of the canal or the apical foramen.[19] It is documented that

in cases of apical periodontitis, intra-canal bacteria can

penetrate dentin to a depth of 150-250 μ, where they remain

protected from the action of medicament and irrigants.[20]

Therefore, apical canal widening to 300-500 μ is required to

thoroughly cleanse the apical portion of the canal

Apical foramen widening was done with gradually

increasing number of files till no #25 or #30 This allowed

thorough cleaning of cemental part of the canal and also

ensured subsequent smooth passage of instrument taken

past the foramen without breakage

Intentional over-instrumentation past the apical foramen

into the periapical tissues contributes towards healing of

the lesion as well as towards achieving biological barrier of

hard and soft tissues as seen in cases of revascularization of

immature teeth This method of over-instrumentation was

found very effective in resolution of periapical pathology

in a prospective clinical study[21] by the first author in 1988

Various stem cells reside in the periapical region of teeth

such as periodontal ligament stem cells (SCPDL), dental

pulp stem cells (DPSC), bone marrow mesenchymal stem

cells (BMMSC) and more recently identified stem cells from

apical papilla (SCAP) These cells are now documented

to play a role in maturogenesis of immature teeth using

revascularization procedure.[22] It could be hypothesized

that the same mechanism probably takes place in cases

of mature teeth; the bleeding and clot formed in the area

of apical foramen by over-instrumentation can lead to

seeding of stem cells, their proliferation, differentiation and

mineralized tissue formation, sealing the apical foramen

The importance of a tight coronal seal cannot be

over-emphasized Without a coronal seal, bacteria and bacterial

toxins can reach the apex through an obturated canal in

just 20 days.[23, 24] Cavit, a zinc-sulphate based material was

chosen to seal the canal orifices It served two purposes:

(i) calcium sulphate cement is documented to have very

good sealing properties[25] and (ii) in case retreatment was

required, it would be easier to remove from canal orifices

We wish to thank the administration and ethics committee of the

All India Institute of Medical Science, New Delhi for permitting

us to undertake this study We also would like to acknowledge

all the postgraduate students of the department of Conservative

Dentistry and Endodontics for their support during the period of

the study.

DISCLAIMER

The views and opinion reported in this manuscript does

not necessarily reflect the clinical standard of care policies

of J Conserv Dent / IACDE

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How to cite this article: Shah N, Logani A SealBio: A novel,

non-obturation endodontic treatment based on concept of regeneration

J Conserv Dent 2012;15:328-32.

Source of Support: Nil, Confl ict of Interest: None declared.

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