restoration of discolored endo dontically treated anterior …university clinics of dental medicine,...

302THE INTERNATIONAL JOURNAL OF ESTHETIC DENTISTRY

AUTUMN 2018

CLINICAL RESEARCH

Restoration of discolored

endo dontically treated anterior teeth:

a minimally invasive chemo-

mechanical approach

Filippo Del Curto, Dr

Assistant, University Clinics of Dental Medicine, Division of Cariology and Endodontology,

University of Geneva, Geneva, Switzerland

Private Practice, Geneva, Switzerland

Giovanni Tommaso Rocca, Dr med dent

Chef de Clinique Scientifique, University Clinics of Dental Medicine,

Division of Cariology and Endodontology, University of Geneva, Geneva, Switzerland

Private Practice, Morges, Switzerland

Ivo Krejci, Prof Dr med dent

President, University Clinics of Dental Medicine, and

Director, Division of Preventive Dental Medicine and Primary Dental Care, and

Chairman, Division of Cariology and Endodontology, University of Geneva,

Geneva, Switzerland

Correspondence to: Dr Filippo Del Curto

University Clinics of Dental Medicine, Division of Cariology and Endodontology, University of Geneva, 1, rue Michel-Servet,

1211 Genève 4, Switzerland; Tel: +41 223794100; Email: [email protected]


AUTUMN 2018

DEL CURTO ET AL

Abstract

In the case of discolored devitalized

anterior teeth, several treatments are

available to enhance the esthetic out-

come, from noninvasive external/internal

bleaching to freehand resin composites

and more complex prosthetic solutions

such as veneers or full crowns. Innova-

tive computer-aided design/computer-

aided manufacturing (CAD/CAM) chair-

side technologies and the introduction of

new industrially polymerized composite

resin blocks coupled with modern adhe-

sive strategies have reduced both bio-

logical and financial costs compared to

the classic post-core-crown approach.

The aim of this article is to show how

these new materials can be used in as-

sociation with noninvasive internal and

external tooth bleaching to restore a

discolored, fractured, non-vital central

incisor.

(Int J Esthet Dent 2018;13:302–317)


AUTUMN 2018

CLINICAL RESEARCH

discoloration such as traumatic shocks,

which provoke pulp hemorrhaging and

root resorption, as well as iatrogenic

causes such as fluorosis and tetracy-

clines. Internal causes of discolora-

tion are changes in normal tooth shade

caused by dentinal caries and dental

restorations, especially metallic ones.

For anterior teeth, the origin of a discol-

oration is frequently associated with a

loss of tooth vitality or with an endodon-

tic treatment. The many chemical prod-

ucts used during root canal disinfection

and obturation can be identified as po-

tential causes of discoloration (irrigating

solutions, root canal cements, intracanal

medicaments).1

Traditionally, discolored devitalized

teeth were covered by porcelain fused to

metal (PFM) full-ceramic crowns, which

are usually based on a core anchored

in the root by an endodontic post. The

presence of a metallic or high-strength

opaque ceramic coping over the dis-

colored core of the tooth and beneath

the esthetic ceramic masks the core

discoloration and ensures the esthetic

outcome. During the past 40 years, sev-

eral in vivo studies have confirmed the

effectiveness of this technique.2,3 How-

ever, this approach is invasive, both for

the crown and the root, exposing the

tooth to a higher risk of fracture. More-

over, the fabrication of a crown involves

many steps such as postcementation,

core buildup, a temporary crown, and

potential crown lengthening, which in-

creases treatment time and costs. With

the advent of adhesive techniques, the

indications for crowns have been recon-

sidered, and today, therapeutic options

for devitalized teeth based on adhesive

strategies are available. The main reason

Introduction

Esthetic needs of dental patients have

continuously increased over the years.

In industrialized countries, people of

both genders and all ages are constant-

ly confronted with information from the

media that tells them that the way to suc-

cess is through a healthy, beautiful, and

‘white’ smile. The result of this propagan-

da is that esthetics is considered a must

in dentistry today.

A beautiful smile can be jeopard-

ized by tooth and gum disease (caries,

trauma, gingivitis), by tooth and bone ar-

chitecture (orthodontic problems), and

by tooth discoloration. Tooth discolora-

tion (dyschromia) has been widely de-

scribed in the scientific literature and

can be due to extrinsic, intrinsic, and

internalized discolorations.1

Extrinsic causes of tooth discolora-

tion are always associated with extrinsic

direct stimuli such as tea, coffee, ciga-

rettes, plaque, and poor oral hygiene.

Teeth can also be indirectly stained, eg,

by chlorhexidine. All of these agents

concern only erupted teeth. However,

both erupted and non-erupted teeth

can be affected by intrinsic causes of

Fig 1 Patient’s initial condition. Tooth 11 appears

discolored and darker than tooth 21.


AUTUMN 2018

DEL CURTO ET AL

for this paradigm shift is the availability of

efficient adhesive systems that allow for

a more conservative approach as they

do not require any mechanical retention.4

However, the partial or total preserva-

tion of the visible parts of the discolored

tooth is not always an esthetic benefit. In

the case of intrinsic and visible discol-

oration, achieving good esthetics with

minimally invasive restorations can be

a challenge. Thus, the combination of

partial adhesive restorations with chem-

ical bleaching techniques may become

mandatory to obtain satisfactory esthetic

results. This article describes a clini cal

case where bleaching was combined

with a partial indirect adhesive compos-

ite restoration.

Clinical step-by-step

procedure

The presented case was a 25-year-old

male who required emergency treatment

due to the loss of a fragment of tooth 11,

which was previously reattached after

trauma in childhood. The tooth was non-

vital and displayed a non-esthetic dys-

chromia in its coronal third. Tooth 21 also

presented a fragment reattachment, but

was still vital.

The patient’s needs were, firstly, to re-

attach the fragment. Secondly, he want-

ed to improve the esthetics of his smile,

change the old restorations, and remove

the grayish aspect of tooth 11 (Fig 1).

The fragment was first tried in the mouth

to verify if it was repositionable. Then,

it was cleaned, sandblasted, selectively

etched with 35% orthophosphoric acid

(Ultra-Etch, Ultradent), and gently dried.

After the adhesive procedures with a

Fig 2 Fragment reattachment bonding proced-

ures: adhesive treatment of the tooth fragment.

(a) Sandblasting of the old luting composite with

aluminum oxide powder. (b) The residual enamel

and dentin are acid etched selectively with 35% or-

thophosphoric acid for 30 s and 10 s, respectively.

(c) Primer and bonding resin are then applied over

the conditioned surface. The fragment is kept under

light protection.

FL, Kerr), the fragment was protected

from ambient light (Fig 2). Rubber dam

was applied, and the same cleaning

a

b

c

CLINICAL RESEARCH


AUTUMN 2018

procedures were performed on the

tooth. The same adhesive system was

applied on the tooth, which was gen-

tly dried and not polymerized (Fig 3). A

preheated restorative hybrid composite

resin (Tetric, shade A2, Ivoclar Vivadent)

was used for the adhesive luting of the

tooth fragment, which was polymerized

Fig 3 Fragment reattachment procedures: adhesive treatment of the tooth. The same adhesive proced-

ures as described for Fig 2 are performed on the residual tooth. (a) The anterior sextant is isolated with

rubber dam. (b) Sandblasting of the old luting composite with aluminum oxide powder. (c) The enamel

and dentin are acid etched with 35% orthophosphoric acid for 30 s and 10 s, respectively. (d) Primer and

bonding resin are then applied over the conditioned surfaces.

Fig 4 Fragment reattachment bonding procedures: luting of the fragment. (a) A pre-warmed restorative

composite resin is inserted into the cavity before repositioning the fragment. (b) The excesses are removed

and the luting cement polymerized.

ba

dc

ba

DEL CURTO ET AL


AUTUMN 2018

from the buccal and palatal aspects for

40 s each (Fig 4).

During the same appointment, to bet-

ter integrate the fragment of tooth 11,

it was slightly cut back on the buccal

side to allow for stratification of a free-

hand composite resin layer (Fig 5). A

correct micro and macro anatomy were

reshaped on both maxillary central in-

cisors to enhance the esthetics of the

smile (Fig 6).

It was decided to restore the devitalized

incisor with a chairside computer-aided

design/computer-aided manufacturing

(CAD/CAM) composite resin restoration

following the old fracture line of the de-

tached fragment and without any inva-

sive ‘crown-like’ tooth preparation. An

internal bleaching session was planned

before the restorative procedure.

Internal bleaching appointment

for tooth 11

The aim of this appointment was to elimi-

nate or at least reduce the grayish aspect

of the visible part of tooth 11 (Fig 7). The

appointment started with the preparation

Fig 5 Once the polymerization is completed, a

small cavity is prepared on the vestibular surface

of tooth 11, and a new freehand composite resin is

stratified to hide the margin between the tooth and

the fragment.

Fig 6 Micro and macro details of the anatomy are

reshaped on the buccal surface of both central inci-

sors.

of the palatal cavity to fill in the bleach-

ing product. The cavity was 1 to 2 mm

deeper than the free gingival margin due

to the specific sinusoidal anatomy of the

dentinal tubules in the cervical region.

Thus, before placing rubber dam to iso-

late the tooth (which would displace the

gum), the position of the free gingival

margin (minus 2 mm) in relationship to

the incisal tooth edge was recorded. This

measurement would be used later dur-

ing transferral to the tooth cavity (Fig 8).

Following rubber dam isolation of the

tooth, the palatal cavity was excavated

until the previously recorded measure-

ment and the integrity of the endodon-

tic treatment were checked with a probe

and with apical radiography (Fig 9). The

peripheral enamel was etched with 35%

orthophosphoric acid (Ultra-Etch) for

30 s, rinsed with cop ious water spray,

and dried. A mixture of distilled water

and sodium perborate was placed in-

to the cavity (Fig 10). The enamel was

cleaned of bleaching mixture excesses

with a wet applicator, and the entire sur-

-

CLINICAL RESEARCH


AUTUMN 2018

this etched enamel ‘ring’ and polymer-

ized for 20 s with a LED light-curing lamp

(L.E. Demetron II, 1200 mW/cm2, Kerr).

A flowable composite resin (Tetric Evo-

Flow, Ivoclar Vivadent) was then applied

over the mixture into the small remaining

cavity and polymerized immediately for

20 s. After rubber dam removal, the oc-

clusion was checked and adjusted. The

mixture was left in place for 1 week, and

the procedure was repeated for another

week. A good whitening effect was ob-

tained after these two internal bleaching

sessions (Fig 11).

After removal of the bleaching mix-

ture at the end of the bleaching proced-

ure, the cavity was abundantly rinsed

Fig 7 The result after 1 week. After rehydration

of the teeth, the discoloration of the cervical part is

clearly visible.

Fig 8 the future internal cavity (the distance between the

incisal edge to 2 mm below the free gingival margin)

is recorded with a red marker on a periodontal probe.

This measurement will later guide cavity excavation.

Fig 9 (a) The cavity is ex-

cavated and the endodontic

treatment checked. (b) Apical

radiograph of tooth 11 shows

no signs of periapical suffering.

with water and a temporary restoration

(Cavit, 3M ESPE) was inserted and left

in place for 1 week. An interval of at least

1 week must be respected before the

permanent palatal adhesive composite

restoration to avoid potential negative in-

terference of the bleaching radicals with

the adhesive procedures.5

External home-bleaching session

The esthetic aspect of both incisors was

reevaluated 2 weeks later. Tooth 21 ap-

peared darker and more yellow than

tooth 11. A potential cause for this ef-

fect might have been a progressive de-

velopment of sclerotic dentin, which is

ba

DEL CURTO ET AL


AUTUMN 2018

common in traumatized teeth.6 For this

reason, a home bleaching agent (PURE

10% carbamide peroxide, Axis Dental)

was programmed to reduce the differ-

ence in the shade between the central

incisors before the restoration. A global

home bleaching on all teeth for 4 days

was first realized, followed by a local-

ized home bleaching of tooth 21 for an-

other 2 weeks.

Cavity preparation for the

definitive CAD/CAM restoration

digital impression of tooth 11 was taken

(Cerec Omnicam software, version 4.4,

Sirona) to copy the shape of the central

incisor. The temporary restoration was

removed with diamond burs under cop-

ious water spray. The cavity was then

isolated and all dentinal surfaces sealed

with an adhesive system (Optibond FL),

following the immediate dentin sealing

or dual bonding procedure.7

Afterwards, the cavity was coated

with a thin layer of composite resin

(Tetric EvoCeram, shade A2, Ivoclar

Vivadent) to fill undercuts and the pulpal

chamber. A small cavity (3-mm deep)

was cut in the middle of the composite

resin in the region of the pulpal cham-

ber. The purpose of this cavity was to

increase the adhesive surface and re-

tain the position of the restoration dur-

ing adhesive luting.8 -

pressions were taken, the peripheral

enamel was finished with fine diamond

burs (granulometry 40 μm) (Fig 12). An

optical impression of the cavity was

taken (Cerec Omnicam), and the com-

posite resin endocrown restoration was

Fig 10 A mixture of sodium perborate and dis-

tilled water is inserted into the cavity without any

gutta percha protection.

Fig 11 Esthetic result after two internal bleaching

sessions. A small overbleached result is not unwel-

come because of the potential of a relapse of the

bleaching effect.

Fig 12 Cavity preparation. Peripheral enamel is

refreshed with a fine diamond bur.

CLINICAL RESEARCH


AUTUMN 2018

fabricated chairside (Cerasmart, shade

A1 HT, GC) (Fig 13).

Adhesive luting of the endocrown

The CAD/CAM restoration was finished

and polished and then tried in the mouth

with a glycerin gel (Fig 14). The global

anatomy, the interproximal surface con-

tacts, and the fit of the margins were

checked. Then, the internal surfaces

of the indirect resin composite restor-

ation were adhesively treated and pro-

tected from ambient light (Fig 15). The

next step was the adhesive treatment of

the cavity (Fig 16). The presence of only

enamel and composite resin, without the

exposure of dentin, facilitates the adhe-

sive procedure. A conventional photo-

polymerizable hybrid composite resin

was used as luting cement (Tetric A140,

shade A2).

-

ity, the restorative composite resin was

heated to a temperature of about 50°C

to decrease its viscosity.9 Immediately

thereafter, the restoration was inserted

into the cavity and coerced in place

manually. Excesses of luting compos-

ite at margins were removed with the

Fig 13 After optical impression of the cavity, the

restoration is digitally designed (CAD).

Fig 14 CAM restoration is tried in the mouth to check the

marginal adaptation, the interproximal contact

points, and the esthetic integration.

Fig 15 Adhesive procedures for the CAD/CAM restoration. (a) The internal surface is sandblasted with

27 μm aluminum oxide powder. (b) The conditioned surface is then treated for 60 s with a silane solution.

(c) A thin layer of bonding resin is spread over the intaglio surface, then dried gently. The workpiece is

placed under light protection.

ba c

DEL CURTO ET AL


AUTUMN 2018

Fig 16 Adhesive procedures for the tooth cavity. (a) After isolation with rubber dam, the cavity is sand-

blasted with 27 μm aluminum oxide powder. (b) Acid etching on enamel (30 s). (c) Alcoholic primer is

applied on the composite resin to clean the sandblasted surface, then dried gently. (d) The bonding resin

is applied and dried gently without polymerizing it.

Fig 17 A restorative hybrid composite resin (Tet-

ric A140, shade A2) is used as luting cement. (a) After preheating, the composite resin is spread onto

the entire cavity. The restoration is first put in place

with a finger. (b) Ultrasonic energy is used to de-

finitively set the CAD/CAM restoration. (c) After the

removal of the excesses, the luting cement is pho-

dam removal, the restoration is fine polished.

a b

c d

a b

c

CLINICAL RESEARCH


AUTUMN 2018

Fig 18 Rubber dam is removed and static/dy-

namic occlusions are checked. The patient is able

to leave the practice with a permanent restoration.

Fig 19 A thin layer of about 1.5 mm of the CAD/

CAM monolithic restoration was cut back on the

buccal side with a diamond bur. At the same time,

the old composite on tooth 21 was removed.

Fig 20 Esthetic modifications of the CAD/CAM restoration. (a) After isolation with rubber dam, the buc-

cal side of the CAD/CAM restoration is sandblasted with 27 μm aluminum oxide powder. (b) Orthophos-

phoric acid etching gel is applied first on the enamel, previously beveled (for 30 s), and then on the dentin

(10 s). (c)later dried gently. The application of alcoholic primer on the CAD/CAM composite restoration cleans the

sandblasted surface. This is a fundamental step in case of accidental dentin exposure during the cutback

procedure. (d)

help of a probe and interproximal floss.

A final push with a plastic ultrasonic tip

helped to seat the restoration in its final

position. A first light polymerization with

a high-power LED unit (L.E. Demetron

II, 1200 mW/cm2) to harden the surface

a b

c d

DEL CURTO ET AL


AUTUMN 2018

(e)in the reconstitution of the palatal wall of tooth 21. (f) Thanks to the palatal silicone index, the palatal wall

of tooth 21 is built up (Filtek Supreme XTE, shade A1 enamel). (g) A dentinal core is built up on both teeth,

-

fect, shade Azur, Edelweiss DR) is applied between the three lobes, and the bevel is covered with a medium

translucency composite resin (Filtek Supreme XTE, shade A1 body). (h) A final layer of high translucency

composite resin is applied, and both restorations are polished before rubber dam removal.

of the luting composite was performed

for 5 s per surface, from the buccopala-

tal direction. Then, full polymerization in

contact with the irradiated surface was

achieved by light curing for 90 s per sur-

face, under simultaneous air and inter-

mittent water spray cooling (Fig 17).10

Any remaining composite excess

was subsequently removed with fine

diamond burs, and the margins were

polished with flexible discs and silicone

points with slight pressure. Finally, rub-

ber dam was removed and the occlu-

sion was checked (Fig 18).

Final esthetic modifications

of the CAD/CAM restoration

After 1 week and full rehydration of the

tooth, the shade integration was eval-

uated. As it did not correspond to the

patient’s expectations, a thin layer of

the CAD/CAM monolithic restoration

(1.5 mm) was cut back on the buccal

side and the old composite on tooth 21

was removed (Fig 19). A new esthetic

freehand composite resin was layered

on both teeth (Filtek Supreme XTE,

shade A2 dentin, A1 body, A1 enamel,

3M ESPE) (Fig 20). The final integration

of the restorations was evaluated after

1 month (Fig 21).

e f

g h

CLINICAL RESEARCH


AUTUMN 2018

Discussion

In the case of a discolored devitalized

anterior tooth, the margins of the restor-

ation should be put into the cervical third,

close to the free gingival line, to hide the

discoloration and achieve an optimal es-

thetic outcome. Unfortunately, this prep

configuration, which is typical for a PFM

or full-ceramic crown preparation, would

mean a radical loss of sound hard den-

tal tissue. At the same time, it is difficult

to reach a perfect esthetic integration

when restoration margins are localized

in the middle of the buccal wall, espe-

cially when the cervical part of the tooth

shows a major staining. Therefore, in the

presented case, the decision to associ-

ate a chemical treatment (internal tooth

bleaching) with a conservative restora-

tive technique (‘endocrown’ or partial-

crown restoration) was taken in order to

be conservative as well as achieve good

esthetics.

For this case report, a chairside CAD/

CAM composite resin endocrown with a

minimal extension into the pulp cham-

ber was used. Considering the exten-

sion of the incisor fracture (more than

half of the tooth), an industrially poly-

merized resin was preferred to a free-

hand direct composite resin, because

of the improved mechanical proper-

ties. In fact, a resin CAD/CAM block

is fabricated under standardized and

controlled high-pressure/high-temper-

ature polymerization conditions. The

resin composite produced is highly

homogeneous, and its mechanical

properties are superior to those pro-

duced by chairside photopolymerized

resin. On the other hand, concerns

may arise due to the limited esthetics

of a monochromatic CAD/CAM restor-

ation. An esthetic modification of the

raw workpiece after milling was nec-

essary to enhance the esthetics of the

buccal surface. For this purpose, the

superficial part of the raw restoration

was removed (approximately 1.5 mm),

and a new esthetic composite resin

was layered over the buccal surface.

Rocca et al11 have recently shown in vitro that for premolar endocrowns, this

buccal veneering does not jeopardize

the mechanical integrity of the milled

restoration. A more expensive alterna-

tive to this buccal re sin veneering could

have been a laboratory-made ceramic

veneer. Compared to a classical post-

core-crown solution, both strategies al-

low for an easy reintervention into the

root canal in case of endodontic prob-

lems or bleaching relapse.

Fig 21 (a) One-month recall.

This final intraoral photograph

shows an optimal esthetic inte-

gration of both restorations. (b) Postoperative radiograph.

a b

DEL CURTO ET AL


AUTUMN 2018

must be prepared properly to contain the

bleaching mixture. The internal side of

the buccal wall must be cleaned of any

generic restorative materials or medical

paste that could invalidate the diffusion

of the mixture through dentinal tubules.

The cavity should be extended up to

2 mm below the free gingival margin, as

in this zone tubules have a distinctive

sinusoidal anatomy. In the present case,

a mixture of sodium perborate and dis-

tilled water was used,12,13 and two ap-

plications of the bleaching agent were

necessary to obtain the desired result.

Depending on local jurisdiction, it may

be more advisable to use a CE-marked

product for this purpose.

A mild bleaching agent was chosen to

reduce the risk of external resorption14

as well as to prevent the reduction of

both enamel and dentin surface micro-

hardness.15 The association between

sodium perborate with distilled water or

H2O2 at different percentages has been

thoroughly debated. Some authors re-

port no significant differences in the ef-

fectiveness of these two mixtures.16,17

Another study underlined the fact that

with a mixture of sodium perborate and

distilled water, results were more stable

in time.18

Once the cavity is prepared, the

bleaching mixture is applied directly into

the root canal in contact with the gutta

percha obturation. The scientific litera-

ture has previously suggested the need

to protect the gutta percha material with a

composite resin or a glass-ionomer layer

to prevent the diffusion of the bleaching

agent into the root canal and into the tu-

bules of the cervical dentin.19,20 Steiner

and West21 suggested that the sealing

material should reach the level of the

cementoenamel junction (CEJ), which

corresponds to the epithelial attachment

level in healthy conditions, to avoid the

leakage of bleaching agents into the

periodontium. According to the normal

anatomy of the CEJ, at the interproximal

sites its level is more in a coronal pos-

ition rather than in the palatal and buc-

cal regions. Thus, as the gutta percha

capping is normally flat, many dentinal

tubules in the interproximal area are still

open toward the perio dontium. This is

why the same authors suggested that

the barrier should be placed 1 mm more

coronal to the buccal CEJ level. Con-

cerns regarding this technique derive

from the fact that the use of this protective

material can hinder the effectiveness of

the mixture in the cervical region, where

the bleaching effect is mainly expected.

Thus, in case of a mild bleaching mixture

(eg, sodium perborate mixed with dis-

tilled water), the gutta percha capping

can be avoided.22 In addition, the risk of

root cervical resorption could be associ-

ated with other preconditions such as an

orthodontic treatment, a trauma, and/or

an internal bleaching with heat activa-

tion.23 Sodium perborate mixtures seem

less involved in resorption problems; a

potential reason for this could be that

sodium perborate prevents the action of

macrophages during bone resorption.24

The negative interaction of bleaching

agents with adhesive systems has also

been discussed. In particular, oxygen

radicals that derive from the degradation

of H2O2 are supposed to inhibit the poly-

merization of adhesive systems and thus

reduce adhesion to bleached tissues.25

A time interval of at least 1 week needs

to be respected before the application


AUTUMN 2018

CLINICAL RESEARCH

of the adhesive systems to allow for the

dispersion effects of the radicals.26,27 A

more recent article showed that there is

no statistically significant difference in

bond strength values between 7, 14,

and 21 days after bleaching.5 In any

case, the neutralization of the residual

pero xide degradation radicals is time

dependent.28 The use of water to rinse

the cavity has been demonstrated to ac-

celerate the neutralization of the expect-

ed radicals because hydrogen peroxide

is extremely unstable in the presence of

water.29,30

A flowable composite resin was used

as a temporary filling after each bleach-

ing appointment instead of the clas-

sic glass-ionomer cement. Flowable

composite resin is easy to apply, and

once polymerized is more resistant than

class ical glass-ionomer materials. In-

ternal bleaching requires a stable and

tough temporary restoration to avoid the

diffusion of the bleaching agent into the

mouth as well as prevent the recontami-

nation of the pulp chamber by bacteria

or staining agents.31 The choice of a re-

storative composite resin for a temporary

restoration is discouraged, as this resin

as an interim restoration, being highly

viscous, can push the whitening product

outside the cavity during application. A

flowable composite resin, on the other

hand, can be directly applied on the soft

bleaching mixture without any pressure.

Due to the combination with an adhesive

system, it allows for a perfect seal.

Conclusion

The clinical case presented in this re-

port shows how the association between

modern adhesive procedures with an

internal bleaching technique allows for

the esthetic restoration of a discolored

endodontically treated incisor without

the use of classic invasive prosthetic

solutions. This combination can recon-

cile the restoration of devitalized teeth

to faster and cheaper minimally invasive

esthetic treatments.

Acknowledgment

The authors would like to thank Dr Eric

Romelli for the revision of the English

language.

References

1. Amhed HM, Abbot PV.

Discouloration potential

of endodontic procedures

and materials: a review. Int

Endod J 2012;45: 883–897.

Rein C, Ferger P. Survival

time of cast post and cores:

a 10-year retrospective

study. J Dent 2007;35: 50–58.

3. Fokkinga WA, Kreulen CM,

NH. Up to 17-year con-

trolled clinical study on

post-and-cores and cover-

ing crowns. J Dent 2007;35:

778–786.

4. Rocca GT, Krejci I. Crown

and post-free adhesive res-

torations for endodontically

treated posterior teeth: from

direct composite to endo-

crowns. Eur J Esthet Dent

2013;8: 156–179.

Linden MS, et al. Influence of

in situ postbleaching times

on shear bond strength of

resin-based composite res-

torations. J Am Dent Assoc

2010;141: 300–306.

Darling CL. Optical changes

of dentin in the near-IR as

a function of mineral con-

tent [epub ahead of print

14 Feb 2017]. Proc SPIE

Int Soc Opt Eng 2017 doi:

10.1117/12.2256745.

7. Dietschi D, Spreafico R.

Current clinical concepts

for adhesive cementation of

tooth-colored posterior res-

torations. Pract Periodontics

Aesthet Dent 1998;10: 47–54.

8. Rocca GT, Rizcalla N,

Krejci I, Dietschi D. Evi-

dence-based concepts


AUTUMN 2018

DEL CURTO ET AL

25. Dishman MV, Covey DA,

of peroxide bleaching

on composite to enamel

bond strength. Dent Mater

1994;10: 33–36.

26. Cullen DR, Nelson JA, San-

drik JL. Peroxide bleaches:

effect on tensile strength of

composite resins. J Prosthet

Dent 1993;69: 247–249.

27. Attin T, Hanning C, Wiegand

A, Attin R. Effect of bleaching

on restorative materials and

restorations – a systematic

review. Dent Mater 2004;20:

852–861.

28. Shinohara MS, Peris AR,

Pimenta LA, Ambrosano

GM. Shear bond strength

evaluation of composite resin

on enamel and dentin after

nonvital bleaching. J Esthet

Restor Dent 2005;17: 22–29.

29. Titley KC, Torneck CD, Ruse

ND, Krmec D. Adhesion of a

resin composite to bleached

and unbleached human

enamel. J Endod 1993;19:

112–115.

30. Torneck CD, Titley KC,

Smith DO, Adibfar A. Effect

of water leaching the adhe-

sion of composite resin to

bleached and unbleached

bovine enamel. J Endod

1991;17: 156–160.

NM, Pameijer CH, Somma F.

Nonvital tooth bleaching: a

review of the literature and

clinical procedures. J Endod

2008;34: 394–407.

and procedures for bonded

inlays and onlays. Part II.

Guidelines for cavity prep-

aration and restoration

fabrication. Int J Esthet Dent

2015;10: 392–413.

indirect restorations for

posterior teeth: the luting

appointment. Quintessence

Int 2007;38: 543–553.

Onisor I, Ardu S, Krejci I,

Rocca GT. Microhardness

of light- and dual-polymer-

izable luting resins polymer-

ized through 7.5-mm-thick

endocrowns. J Prosthet Dent

2014;112: 942–948.

11. Rocca GT, Sedlakova P,

Saratti CM, et al. Fatigue

behavior of resin-modified

monolithic CAD-CAM RNC

crowns and endocrowns.

Dent Mater 2016;32:e338–

e350.

12. Spasser HF. A simple

bleaching technique using

sodium perborate. NY State

Dent J 1961;27: 332–334.

13. Salvas CJ. Perborate as a

bleaching agent. J Am Dent

Assoc 1938;25:324.

14. Rotstein I. Intra-coronal

bleaching of non-vital teeth.

-

ing techniques in restorative

dentistry. London: Martin

Dunitz, 2001.

15. Lewinstein I, Hirschfeld Z,

Stabholz A, Rotstein I. Effect

of hydrogen peroxide and

sodium perborate on the

microhardness of human

enamel and dentin. J Endod

1994;20: 61–63.

16. Rotstein I. Role of catalase

in the elimination of residual

hydrogen peroxide following

tooth bleaching. J Endod

1993;19: 567–569.

vitro comparison of various

types of sodium perborate

used for intracoronal bleach-

ing of discolored teeth. J

Endod 1994;20: 338–341.

comparison of different types

of sodium perborate used

for intracoronal bleaching of

discoloured teeth. Int Endod

J 2002;35: 433–436.

19. Costas FL, Wong M. Intracor-

onal isolating barriers: effect

of location on root canal

leakage and effectiveness of

bleaching agents. J Endod

1991;17: 365–368.

20. Smith JJ, Cunningham CJ,

Montgomery S. Cervical

canal leakage after internal

bleaching procedures. J

Endod 1992;18: 476–481.

21. Steiner DR, West JD. A

method to determine the

location and shape of an

intracoronal bleach barrier. J

Endod 1994;20: 304–306.

22. Rotstein I, Zyskind D, Lewin-

of different protective base

materials on hydrogen per-

oxide leakage during intra-

coronal bleaching in vitro. J

Endod 1992;18: 114–117.

23. Sulieman MA. An overview of

tooth-bleaching techniques:

chemistry, safety and effi-

cacy. Periodontology 2000

2008;48: 148–169.

24. Jiménez-Rubio A, Segura

JJ. The effect of the bleach-

ing agent sodium perborate

on macrophage adhesion in

vitro: implications in external

cervical root resorption. J

Endod 1998;24: 229–232.

restoration of discolored endo dontically treated anterior …university clinics of dental medicine,...

Documents