International Dental Journal

ORIGINAL ARTICLE
doi: 10.1111/j.1875-595X.2012.00117.x

Arrest of non-cavitated dentinal occlusal caries by sealing

pits and fissures: a 36-month, randomised controlled
clinical trial
Boniek Castillo Dutra Borges1, Juliane de Souza Borges1, Rodivan Braz2,
Marcos Antônio Japiassú Resende Montes2 and Isauremi Vieira de Assunção Pinheiro1
1
Department of Dentistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil; 2Department of Restorative Dentistry,
University of Pernambuco, Camaragibe, Pernambuco, Brazil.

Objective: This study aimed to evaluate the progression of sealed non-cavitated dentinal occlusal caries in a randomised
controlled clinical trial. Materials and methods: Sixty teeth with non-cavitated dentinal occlusal caries were selected in
patients with a high risk for caries. Patients were randomly divided into two groups so that each group included 30 teeth.
Patients in the experiment group were given oral hygiene instructions and a fissure sealant. Patients in the control group
were given oral hygiene instructions only. Caries progression and sealant loss were monitored over a period of 36 months by
clinical and radiographic examinations. Results: Clinical and radiographic progression of caries was significantly more
frequent in the control group than in the experiment group. Three teeth lost their sealant and showed caries progression, but
this was apparent only at the 12-month follow-up. At the 24- and 36-month recall appointments, neither sealant loss nor
caries progression were observed. Conclusion: The pit and fissure sealant utilised in this study was shown to be effective in
arresting carious lesions at 36 months.
Key words: Dental caries, dentine, prevention

In restorative dentistry, the treatment of carious lesions and radiographic outcomes of sealing non-cavitated
has been reviewed many times. Minimally invasive dentinal occlusal caries over a period of 36 months.
dentistry, the goal of which is to preserve the greatest
amount possible of tooth structure, is intended to
MATERIALS AND METHODS
replace conventional procedures1. When an open cavity
is diagnosed, the option of restoration tends to be This randomised controlled clinical trial was approved
unquestionable. However, it should be noted that caries by the ethics committee of the Federal University of Rio
involving dentine may be present in non-cavitated Grande do Norte (Natal, RN, Brazil) (protocol no.
lesions and that there may be a layer of intact enamel2. 121 ⁄ 05) and was conducted in full accordance with the
Given the lack of evidence indicating that dentinal World Medical Association’s Declaration of Helsinki.
caries can be arrested, some investigators have recom- Before enrolling patients in the trial, informed consent
mended more invasive treatment to manage non- was obtained by asking prospective patients to read and
cavitated dentinal lesions3,4. By contrast, other sign a form containing all information regarding the
researchers5,6 have demonstrated that non-surgical risks and benefits entailed in the treatment.
interventions are capable of arresting cavitated dentinal
caries. Recently, a 12-month follow-up clinical trial7
Study population
showed that the sealing of pits and fissures halted the
progression of non-cavitated dentinal occlusal caries. This 36-month randomised controlled clinical trial was
Although such short-term results7 highlighted the conducted according to the criteria defined in the
possibility of treating non-cavitated dentinal occlusal CONSORT statement. All procedures were conducted
caries using a non-surgical approach, longterm follow- in the city of Natal (RN, Brazil), which is devoid of a
up investigations remain scarce in the literature. For fluoridated water supply. Patients with high risk for
this reason, this study aimed to investigate the clinical caries8 who attended the National Health Service
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Borges et al.

(Federal University of Rio Grande do Norte) for dental radiolucent area (occlusoapical and ⁄ or mesiodistal
care were selected. directions, in mm). After 15 days, the same examiner
Over a period of 3 months (intake period), 60 (n = 30 re-evaluated 39.1% of the radiographs to determine
per group) molars in 35 individuals (10–22 years of age) intra-examiner agreement (kappa coefficient: 0.9).
were selected. A sample size of 30 per research
treatment is recognised as adequate to afford levels of
Clinical procedures (experiment and control groups)
variability that enable a pertinent conclusion9,10. The
criterion for inclusion was the presence of visually non- To confirm the absence of clinically visible cavitation on
cavitated lesions between the enamel–dentine junction the occlusal surfaces, one operator carried out a prophy-
and the middle one-third of dentine. Exclusion criteria laxis with pumice and water, as well as a clinical
were the presence of restorations and white spot lesions examination with a flat mirror (SS White Duflex, Rio de
or cavitations on other tooth surfaces. Teeth with Janeiro, RJ, Brazil), triplex syringe and headlight (Gnatus
reported sensitivity to any type of stimulus were also Equipamentos Médico-Odontológicos Ltda, Araraqu-
excluded. All visual and radiographic examinations ara, SP, Brazil). In order to standardise the bitewing
were performed by one calibrated operator. radiographs, silicone bite records and a positioner
Each eligible tooth was assigned a number; these (Indusbello, Londrina, PR, Brazil) were utilised. On all
numbers were noted on individual pieces of paper occasions, the same X-ray source [Timex 70C mobile
which were subsequently put into a sealed opaque column (exposure time: 0.64 seconds); Gnatus Equipa-
envelope. An external examiner withdrew one paper at mentos Médico-Odontológicos Ltda] was used to expose
a time and allocated 30 teeth to each group. Patients in Kodak E-Speed films (Eastman Kodak Co., New York,
the experiment group received: (i) instructions on oral NY, USA). The films were manually processed in Kodak
hygiene, and (ii) an opaque pit-and-fissure sealant. The developing and fixative solutions using the following
control group received oral hygiene instructions only. temperature and time protocol: 2 minutes in the devel-
Background and demographic variables of subjects are oping solution and 4 minutes in the fixative solution at a
displayed in Table 1. temperature of 26 C.
All patients received oral hygiene instructions that
included the Fones technique11 for daily tooth brushing
Examiner calibration
and the use of dental floss after meals. In addition, the
Before the study began, one blinded examiner was operator recorded all possible fluoride sources used.
calibrated to analyse the radiographs. During the cali-
bration process, 104 radiographs obtained in a previous
Clinical procedures (experiment group)
study were used; 52 of these were baseline radiographs
and 52 were taken at follow-up at 1 year. The examiner After placement of a rubber dam (Indústria e Comércio
paired the radiographs and evaluated them blindly in a de Artefatos de Látex, São José dos Campos, SP, Brazil),
dark room using a negatoscope, a 2· magnifying glass a prophylaxis was carried out with a Robison brush
(Maped do Brasil Ltda, São Paulo, SP, Brazil), and a containing pumice and water (Microdont, São Paulo, SP,
millimetre ruler (Prisma Instrumentos Odontológicos, Brazil). The occlusal surface was etched with 37%
São Paulo, SP, Brazil). Another person took note of phosphoric acid for 30 seconds, washed for 1 minute
outcomes of increase, decrease or no change in the with an air ⁄ water spray, and dried with an air stream
immediately thereafter. The next step consisted of
applying a fluoride-releasing, resin-based sealant (Dents-
Table 1 Demographic data for the subjects included in ply/Caulk, Milford, DE, USA) with a dental probe (SS
this study White Duflex) in order to secure a better flow of the
Variables Experiment group Control group material throughout the pits and fissures. The sealant
(n = 30 teeth) (n = 30 teeth) was photoactivated for 20 seconds with a light-curing
Age, years, median 16 (12.0–19.5) 13 (12.0–15.0)
device (Optilight LD MAX; Gnatus Equipamentos
(IQ range) Médico-Odontológicos Ltda), which gives a radiance
Gender, n (%) of 600 mW ⁄ cm2), and checked for complete sealant
Male 16 (51.6) 15 (48.4)
Female 14 (48.3) 15 (51.7)
coverage by visual inspection with the aid of a dental
Tooth position, n (%) probe. Occlusal contacts were examined with an artic-
Lower 22 (56.4) 17 (43.6) ulating paper and any premature contact was eliminated.
Upper 8 (38.1) 13 (61.9)
Occlusion, n (%)
Contact with antagonist 3 (100) 0
tooth
Observation periods
Infraocclusion 27 (47.4) 30 (52.6)
The experiment8 and control groups were followed up
IQ range, interquartile (25th–75th) range. at intervals of 4 months over a period of 1 year to allow
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 Progression of sealed caries lesions

intervention in the event of caries progression. After 24 months and 36 months, all 26 teeth in the experi-
8 months, caries progression was observed in the ment group were re-evaluated (Figure 1). During
control group either by clinical or by radiographic recalls, patients reported the use of fluoridated tooth-
examination. Because these teeth had to be restored, pastes only; these included: Colgate Máxima Proteção
they were not included in the subsequent follow-ups. Anticáries (Colgate-Palmolive Ldta, São Paulo, SP,
After 1 year, the experiment group was assessed at Brazil), 1500 ppm fluoride; Tandy Morango (Colgate-
intervals of 12 months up to 36 months. At each time- Palmolive Ldta), 1100 ppm fluoride; Tandy Uva
point, the same operator collected a dental history and (Colgate-Palmolive Ldta), 1100 ppm fluoride, and
also performed both clinical and radiographic examin- Colgate Total 12 Clean Mint (Colgate-Palmolive Ldta),
ations. Patients were asked to report the presence of any 1450 ppm fluoride.
sensitivity to any type of stimulus and to report on the With regard to sealant retention, full retention was
use of fluoride during the time preceding the appoint- observed in 23 of the 26 teeth evaluated at 12, 24 and
ment. Clinical examination consisted of an evaluation 36 months. Partial retention was noticed in two teeth
of the presence of visible cavitation and (in the and complete loss was observed in one of the 26 teeth
experiment group only) of the marginal integrity of evaluated at 12, 24 and 36 months. Material loss was
the sealant. Full retention, partial retention and com- apparent only at the 12-month recall appointment.
plete loss were the expected outcomes. At the 12-month recall appointment, a statistically
One experienced and calibrated examiner evalu- significant difference was detected by Fisher’s exact test
ated the radiographs at 12, 24 and 36 months. between teeth allocated to the experiment and control
Clinical progression was defined by the presence of groups, respectively. Caries progression was present in
visible cavitation and ⁄ or sensitivity during follow-up. three teeth with sealant loss (either partial or complete).
To assess radiographic progression, baseline radio- These lesions were restored and excluded from future
graphs were compared with control radiographs assessments. Subsequently from 12 months, the inci-
using a negatoscope and a magnifying glass. Caries dence of teeth presenting with caries progression was
progression was defined as an increase in the size of null (Table 2).
lesions in any of the directions considered (occluso-
apical and mesiodistal). Caries arrest was defined by
the occurrence of either no change or a reduction in
one or both dimensional planes at 12, 24 and
36 months.
Sealant was replaced whenever loss of material was
observed in the absence of caries progression. In both
groups, restorations with composite resin (Filtek P-60;
3M ESPE Division, St Paul, MN, USA) were carried out
in the presence of any sign of caries progression (tooth
sensitivity, occurrence of visible cavitation, increase in
the radiolucent area).

Statistical analysis
Data were entered into a Windows Microsoft Excel
2007 datasheet and analysed using BioEstat Version 5.0
(Sociedade Civil Mamiraruá, Belém, PA, Brazil) to
generate descriptive statistics and Fisher’s exact tests to
draw comparisons. A level of significance of 5% was
considered.

RESULTS
Four participants (four teeth) were lost at the 12-month
recall appointment from the experiment group and at
the 8-month recall appointment from the control
group. At the 8-month follow-up, the majority of
teeth (25 ⁄ 26) that had been allocated to the control
group showed caries progression. These were restored
and excluded from subsequent follow-up recalls. At Figure 1. Flowchart of the trial.
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Borges et al.

Table 2 Number of teeth with clinical and ⁄ or Since the introduction of pit and fissure sealing in
radiographic caries progression in the experiment and the 1960s16, dentists have assumed that caries, espe-
control groups at each follow-up appointment cially that affecting dentine, may progress beneath
sealants. However, in a 10-year follow-up study,
Follow-up appointment
Mertz-Fairhurst et al.5 confirmed that composite res-
12 months* 24 months 36 months P-value torations placed over frankly cavitated lesions were
(n = 26) (n = 23) (n = 23)
capable of arresting caries progression. Alves et al.6
Experiment 3 (11.5%) 0 0 – obtained similar results in caries arrest when they
group, n (%) partially removed carious dentine from deep caries
Control 25 (96.1%) – – –
group, n (%) lesions. Given these findings, we decided to investigate
P-value < 0.001 – – the efficacy of sealing pits and fissures in teeth with
*8 months in the control group. non-cavitated dentinal occlusal caries in an attempt to
Fisher’s exact test. achieve caries arrest as a secondary preventive
approach. Previous 12-month follow-ups involving
either deciduous17 or permanent7 teeth, together with
DISCUSSION
the results from the present investigation, confirm that
The results of this work show that the progression of the progression of non-cavitated dentinal occlusal
non-cavitated dentinal occlusal caries can be arrested by caries can be arrested by sealing pits and fissures. A
sealing pits and fissures. Although this finding had been connection between caries progression and sealant loss
previously indicated at 12 months7, this length of at 12 months was also apparent. This leads to the
follow-up may be too short to provide the clinician with assumption that the blocking of the nutritional supply
sufficient evidence to seal non-cavitated dentinal occlusal to infected dentine may be the most plausible expla-
caries. By contrast, the results from the present 36- nation for the lack of caries progression observed in
month clinical trial should be of major impact because these studies7,17 and in others reported elsewhere.5,6
this follow-up time is relatively long and thereby When the sealant bond is disrupted, the infected
provides stronger evidence in favour of this approach. dentine resumes its nutritional supply, thus favouring
It is interesting to note that the procedures to restore bacterial growth and caries progression. Therefore,
decayed teeth have evolved considerably in recent regular professional follow-up is necessary when
years. Some years ago, the predominant treatment sealing caries and patients must have easy access to
was much more focused on operative intervention12. regular recall appointments.
Recently, a minimally invasive approach has received The protective barrier provided by the sealant, which
great attention worldwide. This more conservative precludes the passage of stimuli, may well explain the
philosophy is based on sound science that spans the lack of sensitivity in teeth with full material retention
breadth of the disease continuum and includes the non- during recall appointments7. In the present investiga-
surgical management of early non-cavitated carious tion, a resin-based, fluoride-releasing sealant with an
lesions13 and the use of effective conservative interven- opaque colour was chosen because it could be easily
tions for dentinal caries14. It is also recognised that the distinguished from the tooth structure. Resin-based
appropriate management of dental caries must include sealants have relatively good adherence to tooth
the improved diagnosis of early non-cavitated lesions, structure and have increased resistance to wear18, and
and measures for their prevention and arrest. However, thus act as mechanical obstacles to the formation of
some dentists continue to recommend surgical inter- biofilm on the occlusal surface. In addition, the fluoride
vention for non-cavitated dentinal occlusal caries3,4. that is released within a short period of time exerts a
This normally puts the affected tooth into a repetitive cariostatic effect on the enamel surface, thereby
restorative cycle, increasing the risks for adverse effects increasing the effectiveness of treatment19. However,
to the pulp and adjacent teeth14. All these factors as caries arrest is highly dependent upon sealant
contribute to a reduction in the longevity of the tooth retention, researchers must seek ways to improve the
and the restoration. By contrast, the adoption of a non- mechanical strength of sealants. The use of flowable
invasive treatment is expected to minimise the chances composite as a fissure sealant may be an interesting
of secondary caries and early failures of restorations, option in teeth with non-cavitated dentinal occlusal
and thereby to reduce the incidence of tooth fracture caries as its physical properties are superior to those of
caused by extensive restoration and to maintain pulp traditional fissure sealants20,21. An extended period of
vitality for longer15. Thus, the results obtained in this photoactivation can improve physical properties20,21.
36-month follow-up study support the adoption of non- Further clinical trials should be carried out to confirm
surgical treatment for non-cavitated dentinal occlusal the clinical benefits to be derived from the use of
caries by the sealing of pits and fissures with a resin- flowable composites and extended periods of photo-
based material. activation.
4 ª 2012 FDI World Dental Federation
 Progression of sealed caries lesions

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fissure sealant in arresting dentin non-cavitated caries: a 1-year
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the loss of some of the sample at 12 months, which may J Dent 2010 23: 311–316.
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present investigation. However, the remarkable differ- completeness and transparency of reports of randomised trials in
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9. Martı́nez-González MA, Sánchez-Villegas A, Fajardo JF. Bio-
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procedures. Indeed, the lack of caries progression at 12-, randomised clinical trial to evaluate the clinical performance of a
nanofill and a nanohybrid composite. J Dent 2011 39: 8–15.
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None declared. mary molars: a 12-month randomised controlled clinical trial. Int
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Professor Boniek C. D. Borges,
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Email: boniek.castillo@gmail.com

ª 2012 FDI World Dental Federation 5