Influence of chlorhexidine digluconate on theclinical performance of adhesive restorations:A 3-year follow-up

Neimar Sartori a,*, Sheila C. Stolf b, Silvana B. Silva b, Guilherme C. Lopes b,Marcela Carrilho c,d

aDivision of Restorative Science, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USAbDepartment of Operative Dentistry, Federal University of Santa Catarina, Florianopolis, Santa Catarina, BrazilcGEO/UNIBAN, Health Institute, Bandeirante University of Sao Paulo (UNIBAN), Sao Paulo, BrazildDepartment of Restorative Dentistry, Piracicaba School of Dentistry, University of Campinas, Piracicaba, Brazil

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 5

a r t i c l e i n f o

Article history:

Received 24 April 2013

Received in revised form

10 September 2013

Accepted 15 September 2013

Keywords:

Restorative dentistry

Clinical trial

Chlorhexidine

Dentine bonding agents

Composite resins

Non-carious cervical lesions

a b s t r a c t

Objectives: The aim of this clinical study was to evaluate the long-term clinical performance

of non-carious Class V restorations with and without application of chlorhexidine diglu-

conate to acid-etched dentine.

Methods: After the approval of the Ethics and Informed Consent Committee, 70 non-carious

cervical lesions were selected and randomly assigned into two groups, according to the

split mouth design. The control group was restored with a two-step etch-and-rinse

adhesive (Adper Single Bond 2) following manufacturer’s instructions; whereas in the

experimental group 2% chlorhexidine digluconate solution was applied to acid etched

dentine for 30 s after etching and prior to the adhesive application. All lesions were

restored with a nanofilled composite resin (Filtek Supreme XT) and polymerized with a

light-curing unit operating at 600 mW/cm2. Clinical performance was recorded after

1 week, 6, 12, and 36 months using modified Ryge/USPHS criteria in terms of retention,

marginal discoloration, marginal integrity, post-operative sensitivity, and secondary

caries incidence. Data were analyzed using Chi-Square, Fisher’s exact test and McNemar

tests (a = .05).

Results: After 36 months the control group showed a success rate of 88% in comparison to

76% of experimental group; however, no statistically difference between them was found

( p = .463). Moreover, no statistical differences were observed between groups in the criteria

post-operative sensitivity, marginal discoloration, marginal integrity, and secondary caries

incidence between the two groups.

Conclusion: The addition of 2% chlorhexidine digluconate conditioning step does not

improve the clinical durability of adhesive restorations.

# 2013 Elsevier Ltd. All rights reserved.

* Corresponding author at: Ostrow School of Dentistry of USC, Division of Restorative Sciences, Norris Dental Science Center, 925 West34th Street, DEN 4365, Los Angeles, CA 90089-064, USA. Tel.: +1 424 278 3041.

Available online at www.sciencedirect.com

ScienceDirect

journal homepage: www.intl.elsevierhealth.com/journals/jden

E-mail address: sartori@usc.edu (N. Sartori).

0300-5712/$ – see front matter # 2013 Elsevier Ltd. All rights reserved.http://dx.doi.org/10.1016/j.jdent.2013.09.004

1. Introduction

Since enamel etching technique introduction, by Buonocore in

1955, the adhesive systems have been extensively developed.1

The adhesion to the tooth tissues is normally based on

replacement of the tooth minerals, removed with acid-

etching, by resin monomers with low viscosity.2,3 The

heterogeneous composition of dentine tissue, its hydrophilic-

ity, low surface energy, variable permeability and the presence

of a smear layer, make the dentine a challenging substrate to

bond a resin composite restoration.1 Bonding to dentine has

become trustworthier since the introduction of hydrophilic

adhesive systems, which can infiltrate into the wet dentine

substrate, although bonding exclusively to dentine has shown

not to be as durable as expected when hydrophilic adhesive

systems are used.1

Several studies have been investigating the factors respon-

sible for the low durability of the resin–dentine bonds with

hydrophilic adhesives. One reason for this poor performance

is the slow hydrolysis of unprotected collagen fibrils within

and under the hybrid layer by host-derived enzymes in

incomplete resin-infiltrated zones of resin-bonded dentine.4,5

As a result nanoleakage occurs leading to the hydrolytic

breakdown of either the adhesive resin or collagen within the

hybrid layer, thereby compromising the durability of dentine6

Table 1 – Inclusion and exclusion criteria used in thisresearch.

Inclusion criteria

�Patients over the age of 18;

�Patients living in or near to the university;

�Patients with more than 20 natural teeth;

�Presence of two or four non-carious cervical lesions in

different hemiarches (1–3 mm of occluso-gingival height

and 1–2 mm depth);

�Non-retentive cavities, presenting �50% of margins in enamel

and �75% of total area in dentine;

�Presence of adjacent teeth (sound or restored);

�Cervical margins in dentine;

�Regular/good oral hygiene (bacterial plaque visible in <1/4 of

teeth).

Exclusion criteria

�Patients unable to attend follow-up appointments;

�Pregnant or breast-feeding patients;

�Patients using analgesics and/or anti-inflamatory medicine;

�Patients with severe systemic or psychologic disease;

�Patients under orthodontic therapy, using fluoride

supplements or desensitizing agents;

�Patients with bruxism;

�Patients with periodontal/gingival disease;

�Presence of caries, cracks, fractures, premature contact or

unsatisfactory restorations;

�Presence of sclerotic dentine (degree 4), according to the

classification of North Carolina University.25

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 5 1189

bonding interface.

Dentine collagen fibrils degradation is managed by an

intrinsic proteolytic activity of dentine collagenases/gelati-

nases, which would be responsible to cause a progressive

disappearance of portions of hybrid layers over 6–12 months

in vivo.7 So far two kinds of endogenous proteolytic

enzymes with potential collagenolytic/gelatinolytic activi-

ties were identified in dentine: the metalloproteinases

(MMPs)8–11 and the cysteine-cathepsins.12–14 One strategy

to avoid the endogenous collagenolytic activity is the use of

protease inhibitors, such as chlorhexidine,5,15–17 galardin,18

or tetracycline.19 It has been demonstrated that when

chlorhexidine digluconate is used on demineralized den-

tine, after the acid etching and prior to the adhesive system

application, it significantly improves the hybrid layer

integrity, keeping a stronger bonding strength after short-

term clinical trials.7,20

The aim of this study was to evaluate if an additional

conditioning step, after etching and rinsing and prior to the

adhesive application, could improve the clinical performance

of adhesive restorations in non-carious cervical lesions. The

null hypothesis is that the addition of the chlorhexidine

digluconate conditioning step does improve the clinical

durability of composite resin restorations.

2. Materials and methods

After the approval from the Federal University of Santa

Catarina Internal Review Board, thirty patients with non-

carious cervical lesions were selected for this study. Ten

participants were excluded because they did not meet with all

inclusion criteria or they fit in one exclusion criterion

(Table 1).21 Seventy non-carious cervical lesions were selected

in 20 patients, 7 females and 13 males, with a mean age of 46.7

years (range 33–64).

All selected lesions were ‘‘V’’ or ‘‘U’’ shaped in the buccal

surface of teeth with incisal/occlusal margin in enamel and

gingival margin in dentine. The lesions were categorized in

terms of sensitivity (spontaneous or provoked), cervico-incisal

height (1.0–1.5 mm, 1.6–2.5 mm or 2.6–3.0 mm), depth

(�1.5 mm or >1.5 mm), degree of dentinal sclerosis (no

sclerosis, slight, moderate),22 and presence of wear facets

(present or absent). The data of pre-operative evaluation of

selected lesions are presented in Table 2.

2.1. Experimental design and restorative procedures

The best clinical trial to evaluate the effect of chlorhexidine

digluconate used under adhesive restorations is the split-

mouth design. This design was selected because all patients

receive restorations with both adhesive techniques, in differ-

ent quadrants, reducing the influence of patient individual

factors such as sensibility, diet, life style, occlusion, and habits

on results.23 Thus, after being randomly assigned, each patient

received the same number of restorations of both groups,

following the split-mouth design. Seventy lesions, 35 per

group, were restored in 20 patients. Five of them received 2

restorations, one each group, the others 15 patients received 4

restorations, as it is showed in the flow diagram of patients

and restoration in this study (Fig. 1).

Before the adhesive procedures the teeth were cleaned

with pumice-water slurry using Robinson brushes with a

slow-speed handpiece to remove salivary pellicle and any

bacterial plaque. The tooth shade was selected using a shade

guide (VitaPan Classic, Vita Zahnfabrik, Bad Sackingen,

Germany) and the operative field isolation was accomplished

Table 2 – Evaluation methods and number of lesions according to their characteristics.

Evaluation method Number of lesions

Sensitivity Anamnesis and high-pressure air spray for 3 s at a distance of 3 cm

Provoked (non spontaneous) 43

Spontaneous (non provoked) 37

No sensitivity 27

Lesions’ shape Visual and tactil (probe)

‘‘U’’ shaped 25

‘‘V’’ shaped 45

Cervico-incisal height Periodontal probe

1.0–1.5 mm 25

1.6–2.4 mm 21

2.5–3.0 mm 24

Lesions’ depth Periodontal probe

�1.5 mm 39

>1.5 mm 31

Degree of sclerosis Visual and high-pressure air spray

No sclerosis Normal dentine with spontaneous or provoked sensitivity 37

Slightly sclerotic Opaque (or yellow) dentine with spontaneous or provoked sensitivity 6

Moderately sclerotic Yellow (or opaque) dentine without provoked sensitivity 27

Presence of wear facets Visual (after air drying)

Wear facets 70

No wear facets 0

Tooth distribution

Incisors 2

Canine 20

Premolar 40

Molar 8

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 51190

by using labial retractors, cotton rolls and saliva aspirator. A

retraction cord (Knitted Retraction Cord, Pascal Company,

Bellevue, WA, USA) was used to retract the gingiva, exposing

the cervical margins and preventing contamination via

gingival fluid.

The same calibrated operator restored all non-cervical

lesions. Lesions of the experimental group were treated with

a 2% chlorhexidine digluconate (Dermus, Florianopolis, SC,

Brazil) after acid etching and prior to the application of the

adhesive system as describes below: (1) acid-etching with

phosphoric acid (Scotchbond Etchant, 3M ESPE, St Paul, MN,

USA) for 30 s in enamel and 15 s in dentine; (2) rinsing with

air/water spray for 30 s and removal of excess moisture

from dentine using sterilized cotton pellets and drying off

enamel with gentle air streams for 10 s at 2 cm of distance;

(3) application of 2% chlorhexidine digluconate, under

scrubbing action for 30 s using a disposable applicator just

on the experimental group lesions; (4) removal of excess

moisture from dentine and drying off enamel as described

at step 2; (5) application of the adhesive system (Adper

Single Bond 2, 3M ESPE) according to the manufacturer’s

instructions (Table 3); (6) light-curing for 10 s using a

halogen light-curing unit (VIP, Bisco Inc., Schamburg, IL,

USA), with measured light output (600 mW/cm2); (7) resto-

ration was build-up with a nanofilled composite (Filtek

Supreme XT, 3M ESPE) in three increments, beginning by the

gingival margin; (8) light-curing of each increment for 20 s.

Lesions of the control group were restored according to the

protocol described above without the steps 3 and 4.

Final contouring and polishing of the restorations were

performed at the same appointment, using a extra-fine grit

needle-shaped diamond bur (Komet, Lemgo, Germany), silicon

carbide points (Jiffy points, Ultradent Products, Inc., South

Jordan, UT, USA), aluminium oxide discs (Sof-Lex, 3M ESPE),

and polishing pastes (Diamond polish 1 mm and 0.5 mm,

Ultradent Products, Inc.).

2.2. Evaluation procedure

Two previously calibrated examiners who were fully blind to

the treatment carried out evaluated the restorations. The

examiners had Cohen’s Kappa index (K = .894) to inter-

examiner reliability and disagreements between evaluators

were resolved by consensus. The evaluations were performed

at four different periods: at baseline (7 day after restorations

placement), after 6, 12, and 36 months based on ADA’s

guidelines,24 and the USPHS modified criteria.25

The criteria evaluated were: retention, marginal discolor-

ation, marginal integrity, post-operative sensitivity, presence

of recurrent caries, and pulpal vitality. Retention, marginal

integrity, marginal discoloration and occurrence of caries

were used as key parameters determining the overall clinical

success. Post-operative sensitivity was measured subjectively

based on the patient’s response to an air stimulus (air stream,

1 cm distance for 1 s) and recorded according to the Verbal

Rating Scale (VRS).26 Pulpal vitality was assessed based on the

patient’s response to a cold stimulus. A cotton pellet saturated

with a refrigerant solution (ROEKO Endo-Frost, Coltene/

Asses sed for eligibility Np= 30

Excluded (Np=10):- Did not meet inc lusi on crit eria (N P=6)

- Met exclusion criteria (N p=4)

Random ized Np=20, Nr=70

All ocat ed to control Group

Nr=35

Allo cat ed to experimental Group

Nr=3 5

Rece ived al loca ted interv ention

Nr=35

Rece ived al loca ted interv ention

Nr=35

Recal l at 6 monthsNp=20, Nr=32

Recal l at 6 monthsNp=20, Nr=35

Recal l at 12 months

Np=18, Nr=32

Recal l at 12 months

Np=18, Nr =32

Recall at 36 month s

Np=14, Nr=25

Recall at 36 month s

Np=14, Nr=25

- 1 pa tie nt die d,

- 1 pa tien t did n ot follow up

- 2 pa tien ts m ove d,

- 2 pa tien ts n ot f oll ow u p

2 debonds

1 debond debonds 4

Fig. 1 – Flow diagram. Np: number of patients, Nr: number of restorations.

Table 3 – Materials used for the restorations in the research.

Material Manufacturer Composition Batchnumber

Application mode

ScotchBond

Etchant

3M ESPE, St. Paul,

MN, USA

35% H3PO4 5EX 1. Apply on enamel for 30 s and

on dentine for 15 s

2. Rinse for 30 s

3. Dry enamel keeping dentine moist

Chlorhexidine

digluconate

Dermus, Florianopolis,

SC, Brazil

2% Chlorhexidine digluconate (CHX) – 1. Apply on dentine, under scrubbing

action, for 30 s after acid etching

(experimental group)

2. Dry enamel keeping dentine moist

Adper Single

Bond 2

3M ESPE, St. Paul,

MN, USA

Bis-GMA, HEMA, diurethanedimethacrylate,

polialkenoic acid, camphorquinone, water,

ethanol and glycerol 1.3 dimethacrylate,

10% wt. silica nanofillers

5EK 1. Apply two adhesive coats on

both enamel and dentine

2. Evaporate the solvent using

high-pressure air spray for 5 s at

10 cm of distance

3. Light-cure for 10 s

Filtek Supreme XT 3M ESPE, St. Paul,

MN, USA

Bis-GMA, Bis-EMA (6), UDMA, TEGDMA,

nanofillers and silica nanoclusters

5BC 1. Apply in increments with less

than 2 mm thickness

2. Light-cure each increment for 20 s

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 5 1191

Table 4 – Evaluation results in percentage of alpha at each evaluation period.

Recall period

Baseline 6 months 12 months 36 months

SB CHX SB CHX SB CHX SB CHX

Recall rate 100 100 100 100 91.4 91.4 71.4 71.4

Retention rate 100 100 94.3 100 93.5 100 88.0 76.0*

Marginal discoloration 100 100 93.9 97.1 93.1 93.5 72.7* 68.4*

Marginal integrity 100 100 100 100 100 96.8 90.9 78.9

Post-operative sensitivity 82.9 74.3 94.3 67.1 96.6 87.1 95.5 89.5

Absence of caries occurrence 100 100 100 100 100 100 100 100

Pulpal vitality 100 100 100 100 100 100 100 100

Overall clinical success rate 100 100 94.3 100 93.5 100 88.0 76.0*

SB, Control Group; CHX, Experimental Group; percentages of all parameters evaluated refer to retained restorations, except for recall rate,

retention rate and overall clinical success rate.

Baseline percentages for sensitivity refer to evaluation after the restoration. Number of lesions with sensitivity prior to restoration is shown in

Table 2.

There is no statistical difference between both groups at any evaluation. Percentage of Alpha followed by asterisk differs from baseline

evaluation (McNemar test).

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 51192

Whaledent GMBH, Langenau, Germany) was placed on the

restored tooth. Once the patient responded to the cold

stimulation, the cotton pellet was removed and, for a normal

vital pulp, the pain should disappear in a few seconds.

2.3. Statistical analysis

The clinical bonding effectiveness was determined by the

percentage of debonded restorations during the evaluation

period. The data were processed using the Statistical Package

for Social Sciences IBM SPSS Statistics 19 (Chicago, IL, USA)

and descriptive statistic was used to present the results.

Cumulative retention failures were calculated by dividing the

number of lost restorations at the recalls by the total number

evaluated at each of the recalls. Chi-square and Fisher’s exact

tests were used to evaluate the presence of statistical

differences between groups at each recall and McNemar’s

test was used to verify the alpha ratings variation for each

evaluated criteria within the same group over time. For all

statistical analysis a 5% significant level was adopted (a = .05).

3. Results

The percentages of alpha scores, which represent the ideal

clinical situation, are compiled in Table 4. It was observed that

three restorations debonded from premolars of different

patients in the control group within 36-month follow-up.

Two restorations debonded at 6-month recall and another

debonding was observed at 36-month evaluation. These

restorations were placed in shallow lesions (�1.5 mm) with

slight moderate sclerosis level, two of them belonged to ‘‘V’’

shaped lesions and other one to ‘‘U’’ shaped lesions. In the

experimental group, it was noted that 4 restorations debonded

at 36-month recall, three restorations from premolars and one

from a molar. Two restorations were bonded to shallow

lesions (�1.5 mm) ‘‘V’’ shaped and two of them to deep lesions

(>1.5 mm) ‘‘U’’ shaped. The other restorations were bonded to

dentine with moderated sclerosis level, one to a slight

moderate and the other one to a lesion without any sclerosis

degree. Despite there was no statistical difference between the

two groups there is statistical difference between the baseline

and 36 months recalls for the experimental group ( p = .031).

Some clinical acceptable marginal discoloration was

observed in both groups after 36 months, without statistical

difference between them ( p = .763). However, there is statisti-

cal difference between the baseline and 36 months recalls for

both groups (control group, p = .031 and experimental group,

p = .013).

From the 61% of teeth with non-carious cervical lesions

that presented pre-operative sensitivity just 17.1% of the

restored teeth in the control group, and 25.7% in the

experimental group presented post-operative sensitivity after

one week. At 36 months recall the post-operative sensitivity

rate was 4.5% in the control group (one restoration) and 11.5%

in the experimental group (two restorations).

At 36 months recall none of the restored teeth became non-

vital due to the restoration placement and none of them

presented caries occurrence. Thereby, the clinical success

rates of these restorations were 88.0% for the control group

and 76.0% for the experimental group.

4. Discussion

Despite the addition of the chlorhexidine digluconate delayed

the period wherein the restorations started exhibiting unfa-

vourable clinical characteristics; its use did not improve the

clinical durability of adhesive restoration placed to non-

carious cervical lesions at 36-month follow-up. The null

hypothesis that chlorhexidine digluconate conditioning step

does improve clinical durability of composite resin restora-

tions was accepted because there is no statistical difference

between both groups in any criteria.

The durability of resin–dentine bonds can compromise the

lifespan of composite resin restorations, especially in restora-

tions where there is no macro mechanical retention, such as

Class V restorations of non-carious cervical lesions. Resin–

dentine bonds degradation probably occurs via hydrolysis of

suboptimally polymerized hydrophilic resin components and

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 5 1193

degradation of resin-uncovered collagen matrices by matrix

metalloproteinases (MMPs) and cysteine cathepsins.13 Chlor-

hexidine has demonstrated being a potent inhibitor of MMPs

present in the dentine–pulp complex,11,27 such as, MMP-2,

MMP-8, and MMP-9.28 More recently, the inhibitory effect of

chlorhexidine on cysteine-cathepsins activity was also dem-

onstrated,29 indicating that chlorhexidine may have a wide

anti-proteolytic spectrum.

The experimental (treated with chlorhexidine) and control

groups showed similar clinical results at 36-month follow-up

in terms of retention rate. However, in the control group, the

restorations started debonding before 6 months of clinical

function, while in the experimental group none of the

restorations debonded until 12-month evaluation, just at 36-

month recall. Probably, the chlorhexidine treatment improved

mechanical and morphological stability of hybrid layers by

inhibiting the host-derived proteases over time.7 Despite

chlorhexidine could decelerate the rate of resin–dentine bonds

degradation by inhibition of host-derived proteases, chlor-

hexidine could not prevent the hydrolytic breakdown of

polymers that constitute those bonds,11 which could explain

why the restorations of chlorhexidine-treated cavities exhib-

ited a decrease of the rate of retention at 36-month recall.

The two-step etch-and-rinse adhesive used in the present

study consists of a BisGMA/HEMA-based system containing

13% polyalkenoic acid copolymer in an ethanol–water solvent.

This hydrophilic formulation is responsible for making the

material a permeable membrane after its polymerization.

Polyalkenoic acid copolymer can allow cured adhesives to

absorb an extensive amount of water over time,33 due to the

multiple pendent carboxylic acids along its linear backbone,

decreasing the cohesive strength of this adhesive layer.34

Many fundamental differences are found between the

present study and other previous in vivo studies that

employed chlorhexidine as an adjunctive resource to deceler-

ate the degradation of resin–dentine bonds. Apart from the

final evaluation time, factors such as cavity configuration and

type of testing analysis are listed as significant differences.

Hebling et al.,20 Carrilho et al.,7 and Brackett et al.,35 have

performed microscopic analyses of the hybrid layer integrity

formed between chlorhexidine-treated dentine and the etch-

and-rinse adhesive systems, the present protocol chose to

analyze the clinical, macro-response to chlorhexidine used as

a conditioning step. Thereby it was not possible to detect

microscopic differences between control and experimental

group that could show relevant differences in those treat-

ments. Another important aspect that cannot be detected with

the present study is the origin of the adhesive failures,

whether the recorded negative parameters were due to a

defect within the resin or the dentine matrix part of hybrid

layers. Carrilho et al.,7 has shown that, over time, in the

chlorhexidine-treated group, resin-bonded dentine had exhib-

ited a considerably reduction of the number of cohesive

failures within the bottom of hybrid layers. Furthermore

uncovered collagen would be more massively present, which

indicates the proactive effect of chlorhexidine against the

proteolytic enzyme activity.

It is also speculated that the interaction between chlorhex-

idine digluconate and hydroxyapatites on the enamel surface

can be responsible for the restorations debondings on the

experimental group. The chlorhexidine digluconate is a strong

base with cationic properties that can bind to the negatively

charges in trivalent phosphate in the hydroxyapatite crystal-

line lattice, creating a precipitation of needle-shaped birefrin-

gent crystals with the same refractive index as the phosphate

salt on the surface of the enamel.30–32 This precipitate could

act as a physical barrier, limiting the adhesive system

interaction with the hydroxyapatites, minimizing the poten-

tial of bonding.32

The causes of the diminished longevity of non-carious

Class V restorations are still poorly understood, in contrast

with other classes of restorations.36 Failure of cervical

adhesive restorations is often attributed to inadequate

moisture control and also to cuspal movement during

occlusion.37 Clinical studies also associate tooth flexure with

low retention in cervical restorations,38 showing that the para-

axial loading moment developed into the tooth has negative

effects at the cervical restorations interface.39 The repetitive

cyclic of para-functional loadings may induce a failure in the

cervical region of the restoration which undergoes strain

softening, generating micro-cracks at the restoration mar-

gin.36 If this hypothesis is true it can explain why there is a

statistical difference between the baseline and 36 months

recalls in marginal discoloration for both groups. Although it is

not possible correlate these clinical co-variables to retention

loss, the potential effect of excessive occlusal loading on

cervical stress concentration,40 can challenge the tooth–resin

interface.37,38

The results of sensitivity evaluation revealed no statistical

significant differences between groups in any recall, demon-

strating that chlorhexidine digluconate does not increase

post-operative sensitivity. After 36 months of clinical func-

tion, 3 restorations (one restoration in the control group and

two in the experimental group) presented clinical accepted

sensitivity when an air stimulus was applied. These three

restorations were placed to lesions with pre-operative

sensitivity and in the same patient, which may indicate that

patient factor, such as sensitivity, diet, life style, occlusion,

and habits, may influence the results.

Although this study was conducted with a small, well-

selected group of patients, the results suggest that the success

rate of control and chlorhexidine treated groups are similar, at

least within a 36-month follow-up. Other studies are indis-

pensable to evaluate the clinical performance of different

chlorhexidine concentrations applied in different teeth cavity

configurations, longer periods of clinical trials, and restored

using less hydrophilic materials.

5. Conclusion

From the results of this clinical study, chlorhexidine digluconate

conditioning step does not improve the clinical durability in

non-carious cervical restorations within 36-month follow-up.

Acknowledgements

We would like to thank Lais Dalmagro Peruchi and Dr. Sillas

Duarte Jr for editorial assistance. This study was partly

j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 1 8 8 – 1 1 9 51194

supported by the Brazilian Federal Agency for Support and

Evaluation of Graduate Education (CAPES).

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