Comparison of Two Types of Pit and Fissure Sealants in Reducing the Incidence of Dental Caries Using a Split-Mouth Design.

OBJECTIVES: To evaluate the effectiveness of two pit and fissure sealants (PFS) in reducing the incidence of dental caries in schoolchildren.
MATERIAL AND METHODS: A randomized split-mouth experimental design was used in a sample of 140 subjects assigned to two groups. The sealants used were Clinpro©3M and BeautiSealant©Shofu placed in first permanent molars (FPMs). Each sealant was compared to molars in the controls to determine effectiveness over a period of 6 months. The study had a 12.9% loss to follow-up. No statistically significant differences (p>0.05) were observed for sex, age, baseline dmft, or type of sealants. Nonparametric tests were used for statistical analysis.
RESULTS: Average dmft index at baseline was 4.10±3.16. Lower incidence of caries was observed in FPMs with pit and fissure sealants (p<0.01), regardless of the type used. When sealants remained intact there was a lower caries incidence compared to sealants partially or completely missing - but differences were only significant for FPM 16. Caries incidence was higher for BeautiSealant sealed teeth than for Clinpro's, but only statistically significant in FPMs 16, 36 and 46 (p< 0.05). Caries incidence was higher in those cases with a higher baseline dmft but it only reached statistical significance in FPMs 26 and 36. Relative risks for dental caries were lower in sealed teeth (p<0.01).
CONCLUSIONS: Pit and fissures sealants are an effective preventive treatment to reduce caries during a 6-month follow-up in schoolchildren 6 to 8 years of age, regardless of the type of sealant used. The sealant brand that showed greater effectiveness in terms of prevention and retention was Clinpro©3M.

Introduction

According to the Global Burden of Disease in 2010, untreated caries in permanent and primary teeth represented the first and tenth most prevalent condition, respectively (). In Latin America, oral diseases constitute a public health problem (). Specifically, in Mexico six-year olds have caries on their primary teeth, with caries index ranging from 0.73 to 5.35 (decayed, missing and filled primary teeth (dmft index)), and caries prevalence is between 26.3% and 77.5%. For permanent teeth, dental caries index among 12-year olds ranged from 0.52 to 3.67 (Decayed, Missing and Filled Permanent Teeth (DMFT index)) and caries prevalence ranged between 30.7% and 79.2% (). For 15-year-olds, the average DMFT ranged between 1.12 and 5.31, and prevalence between 37.6% and 88.6% (). The results of the studies conducted in developing countries revealed that more than 80% of caries lesions in primary and permanent teeth required restorative treatment. The high prevalence and treatment needs represent an economic burden for both public health systems and households, with the latter often paying out-of-pocket expenses for private care (, ).

First permanent molars (FPMs) are the earliest teeth to erupt in the secondary dentition (). The occlusal morphology of pit and fissures is an important reason for dental caries at this surface. While diverse restorative materials can be used to restore occlusal cavities (), pit and fissure sealants are highly effective preventive interventions whereby a low-viscosity resin is placed in pits and fissures (-). In Mexico, less than 2.5% of children and adolescents aged 6 - 12-years had sealants of any type ().

The present study set out to ascertain the effectiveness of sealants in general in a group of community-dwelling children in terms of caries prevention performance in first permanent molars (FPM). Secondly, we compared the performance of two commonly used sealants: ClinPro©3M and BeautiSealant©Shofu pit and fissure sealants.

Material and methods

Design

We conducted a randomized controlled split-mouth clinical trial in elementary school children in Hidalgo, Mexico. Figure 1 shows the methodological design. Our design included the conventional Clinpro sealant (Clinpro©3M, Saint Paul, MN., USA) and one sealant based on Giomer technology (BeautiSealant©Shofu, Kyoto, Japan). Clinpro©3M is a resin-based product that requires an etching adhesive system (). BeautiSealant©Shofu sealant uses Giomer technology with an adhesive system that does not require phosphoric acid (). Different technologies may affect various aspects of performance (e.g., pit penetration (), retention () and microfiltration (), which was not individually addressed in the present research.

Figure 1

Flowchart of methodological design of the study

Our research protocol was approved by the Ethics Committee of the Health Sciences Institute at the Autonomous University of the State of Hidalgo (Cinv/o/032/2016).

Sealant application

Dental prophylaxis with fluoride-free abrasive paste and rubber cup was carried out at low speed. Relative isolation was attained with cotton rolls. A conventional adhesive system was followed with the Clinpro sealant; that is, the enamel surface was etched for 20 seconds, and after rinsing with plenty of water, the sealant was placed with applicator tips (3MESPE). For the BeautiSealant sealant, first conditioning was attained with air gently applied for 5 seconds, followed by placing the sealant (Shofu). Both products were cured with a LED lamp for 20 seconds. We followed the manufacturers’ instructions.

Study sample and participant selection

A formula for proportional difference was used to calculate the sample size. The prevalence of caries in the FPMs with and without sealants (30% and 60%, respectively) was based on a p-value of 0.05 and 90% power. We added 10% loss to follow-up calculations, leading to 70 participants per sealant.

We selected the participants randomly from ten public elementary schools after holding a meeting with heads of households in each school, before asking for their signed informed consent. Inclusion criteria were () having four fully erupted and sound FPMs; () being enrolled in one of the ten selected schools; () being between six and eight years old; () having no fixed orthodontic appliances; and (5 the child assenting to go through dental examination.

Intervention

Once participants were selected, we performed an initial randomization to determine which sealant would be used for each child. We then performed the second randomization to determine on which side of the mouth the sealant would be placed. Sealants (experimental group) were applied in the first upper permanent molar and first lower permanent molar on the same side of the mouth. In this way, the control group was assigned to the opposite arch.

Data collection and statistical analysis

We used the International Caries Detection and Assessment System II (ICDAS II) to measure caries experience at baseline and follow-up (six months after intervention); dmft index was used at baseline as well. Both the clinical examiner and recorder were calibrated and standardized (kappa >0.80) on this scale. As recommended by other authors (), we assessed pit and fissure sealants during follow-up as 0=intact or complete, 1=partial retention, or 2=missing.

After describing general characteristics of the sample, we performed a bivariate analysis to ascertain whether differences had arisen between the two groups of participants in terms of loss to follow-up, and for each of the independent variables. We performed a chi square test to establish the association between dependent and exposure variables. Finally, we estimated the relative risk (RR) and the incidence of caries in the FPMs with and without a sealant. Given the split-mouth design of our study, the tooth was analyzed so that a comparison could be made with the contralateral tooth.

Variables

Our dependent variable was the incidence of caries, measured dichotomously (0= sound, 1= visible changes in enamel or caries >1 in ICDAS II). Our main independent variable was the presence of sealant (0= without sealant, 1= with sealant). In addition, we analyzed data by sex (0=male, 1= female), age (6-8 years), baseline dmft, type of sealant (0=Clinpro, 1= BeautiSealant) and sealant status six months after placement (0=intact, 1= partial retention, 2= missing).

Blinding

The simple blind design was used; i.e., participants were unaware of group assignment, but researchers were aware of it. Similarly, both clinicians and patients knew that the treatment would be provided, but patients did not know which type of sealant would be applied. The dentists placing the sealants were different from those scoring the caries experience, the presence of sealants, or collecting data for the trial.

Results

Table 1 shows the general sample and demographic characteristics. Of 140 participants, mean of age was 6.92±0.74 years; 52.1% were boys. Mean baseline dmft index was 4.10±3.16. Although the study had a 12.9% loss to follow-up, no statistically significant differences (p>0.05) were observed for sex, age, baseline dmft nor type of sealants between children who left the study and those who completed the follow-up.

Table 1

General sample characteristics at baseline and analysis of participants who remained and did not remain (loss to follow-up) in the study

Variable	Baselinemeasurementn (%)		Lost tofollow up18 (12.9)	Remainedin study122 (87.1)	P value
SexMaleFemale	73 (52.1)67 (47.9)		11 (15.1)7 (10.4)	62 (84.9)60 (89.6)	p=0.415 *
Type of sealantBeautisealantClintpro	70 (50.0)70 (50.0)		11 (8.4)10 (14.3)	62 (88.6)60 (85.7)	p=0.614*
	Mean±SD	Range	Mean±SD	Mean±SD
Age	6.92±0.74	6-8	6.66±0.68	6.96±.74	p= 0.1117**
Baseline dmft	4.10±3.16	0-13	4.33±3.49	4.06±3.12	p=0.8095 **

*Chi2 **Man-Withney

There were no statistically significant differences (p>0.05) in caries incidence in FPMs by age or sex. A lower caries incidence was observed in FPMs with pit and fissure sealants (p<0.01) (Tables 2 and 3), regardless of the type used.

Table 2

Caries incidence in FPM16 and FPM26 vs independent variables

FPM16	Sound	Decayed	P value
Presence of sealantWith sealantWithout sealant	43 (74.1)32 (50.0)	15 (25.9)32 (50.0)	p=0.006*
Sealant statusIntactPartialMissing	36 (81.8)28 (60.9)11 (34.4)	8 (18.2)18 (39.1)21 (65.6)	p<0.0001*
Type of sealantClinproBeautiSealant	45 (75.0)30 (48.4)	15 (25.0)32 (51.6)	p=0.003*
SexMaleFemale	38 (61.3)37 (61.7)	24 (38.6)23 (38.3)	p=0.966*
Age	6.89±0.70	7.08±0.80	p=0.1757**
Baseline dmft	3.74±3.08	4.57±3.15	p= 0.1336**
FPM26
Presence of sealantWith sealantWithout sealant	51 (79.7)17 (29.3)	13 (20.3)41 (70.7)	p<0.0001*
Sealant statusIntactPartialMissing	28 (63.6)27 (58.7)13 (40.6)	16 (36.4)19 (41.3)19 (59.4)	p=0.120*
Type of sealantClinproBeautiSealant	36 (60.0)32 (51.6)	24 (40.0)30 (48.4)	p=0.351*
SexMaleFemale	32 (51.6)36 (60.0)	30 (48.4)24 (40.0)	p=0.351*
Age	6.97±0.71	6.96±0.80	p=0.9383**
Baseline dmft	3.52±2.76	4.74±3.44	p=0.0489**

*Chi2; **Man-Withney; FPM = first permanent molar

Table 3

Caries incidence in FPM36 and FPM46 vs independent variables

FPM36	Sound	Decayed	P value
Presence of sealantWith sealantWithout sealant	50 (78.1)21 (36.2)	14 (21.9)37 (63.8)	p<0.0001*
Sealant statusIntactPartialMissing	27 (61.4)30 (65.2)14 (43.7)	17 (38.6)16 (34.8)18 (56.3)	p=0.145*
Type of sealantClinproBeautiSelant	41 (68.3)30 (48.4)	19 (31.7)32 (51.6)	p=0.026*
SexMaleFemale	37 (59.7)34 (56.7)	25 (40.3)26 (43.3)	p=0.736*
Age	6.92 ± .72	7.01 ± .78	p=0.5221**
Baseline dmft	3.33 ± 2.49	5.07 ± 3.62	p=0.0094**
FPM46
Presence of sealantWith sealantWithout sealant	43 (74.1)27 (42.2)	15 (25.9)37 (57.8)	p<0.0001*
Sealant statusIntactPartialMissing	28 (63.6)27 (58.7)15 (46.9)	16 (36.4)19 (41.3)17 (53.1)	p=0.336*
Type of sealantClinproBeautiSealant	41 (68.3)29 (46.8)	19 (31.7)33 (53.2)	p=0.016*
SexMaleFemale	38 (61.3)32 (53.3)	24 (38.7)28 (46.7)	p=0.314*
Age	6.87 ± .74	7.09 ± .74	p=0.1015**
Baseline dmft	3.71 ± 3.11	4.53 ± 3.1	p=0.1147**

*Chi2; **Man-Withney; FPM = first permanent molar

When sealants remained intact there was a lower caries incidence compared to sealants partially or completely missing – but differences were only significant for FPM 16. The caries incidence was higher for BeautiSealant sealed teeth than Clinpro’s, but it was only statistically significant in FPMs 16, 36 and 46 (p< 0.05). The caries incidence was higher in those cases with a higher baseline dmft but it only reached statistical significance in FPMs 26 and 36.

Table 4 shows the incidence distribution by ICDAS II type of lesion. They were primarily ICDAS 1 and 2; 63.8% of 47 FPM 16, 77.7% of 54 FPM 26, 54.9% of 51 FPM 36 and 48.0% of FPM 46.

Table 4

Caries incidence by type of lesion according to ICDAS II

FPM16	Sound	ICDAS 1 and 2	ICDAS 3	P value
Presence of sealantWith sealantWithout sealant	43 (74.1)32 (50.0)	9 (15.5)21 (32.8)	6 (10.4)11 (17.2)	p=0.022*
FPM26
Presence of sealantWith sealantWithout sealant	51 (79.7)17 (29.3)	10 (15.6)32 (55.2)	3 (4.7)9 (15.5)	p<0.0001*
FPM36
Presence of sealantWith sealantWithout sealant	50 (78.1)21 (36.2)	10 (15.6)18 (31.0)	4 (6.3)19 (32.8)	p<0.0001*
FPM46
Presence of sealantWith sealantWithout sealant	43 (74.1)27 (42.2)	9 (15.5)16 (25.0)	6 (10.4)21 (32.8)	p=0.001*

* Chi square

The caries incidence in sealed and non-sealed FPMs is presented in Table 5. In terms of relative risk (RR), FPMs with pit and fissure sealants had lower caries risk of than those without sealants.

Table 5

Caries incidence and relative risk in teeth with sealant

	IR - exposed	IR - non-exposed	CI	RR	CI 95%	P value
FPM16	25.0	50.0	38.5	0.52	0.52 - 0.85	p=0.0062
FPM26	20.0	70.0	42.2	0.29	0.17 - 0.48	p<0.0001
FPM36	21.8	63.7	41.8	0.34	0.21 - 0.57	p<0.0001
FPM46	25.8	57.8	42.6	0.45	0.27 - 0.72	p=0.0004

IR= Incidence rate; CI= Cumulative incidence; RR= Relative risk

Discussion

Our study demonstrated that pit and fissure sealants are effective for a six-month follow-up period when applied to first permanent molars (FPMs). This is consistent with previous studies in various countries (, ), although the follow-up times differ. While widely acknowledged for effectiveness, it is a pity that in Mexico pit and fissure sealants are not employed as often as it could be expected. According to a report from the Ministry of Health, less than 2.5% of the population surveyed had received sealants (). Given demonstrated effectiveness, health programs should be emphasizing sealant utilization in public and private dental services, as it has often been recommended in other countries (, ).

Caries lesions are predictive of new ones (); a previous history of caries experience suggests an increased risk (). Pit and fissure sealants are especially indicated for children at risk of developing caries. When we analyzed the relationship between the initial appearance of caries in primary dentition and the incidence of caries in sealed teeth, we found higher incidence of caries in patients with greater dmft at baseline. Despite our limited follow-up time, overall results strongly support the use of sealants (, -).

The BeautiSelant©Shofu sealant utilizes glass ionomer together with a polymer in its composition, which offers the advantage of releasing and recharging fluoride. Recent studies have compared this type of technology to conventional sealants with favorable results (, ). Cinpro©3M is a resin-based sealant that releases fluoride. It has been suggested that this type of sealant provides greater benefits as it tends to remain longer in the mouth (): resin-based sealants offer extended retention as a result of the adhesive system used (). Our study results showed a smaller number of missing sealants and a lower level of caries in FPMs when Clinpro©3M sealants had been used. The effectiveness of pit and fissure sealants is closely related to their permanence on the tooth surface (-). However, we found no differences in terms of the incidence of caries in relation to retention. Our study differed from others because our follow-up measurement was limited to six months; the effect of total or partial loss of sealants may have been more evident over a longer period.

While selection criteria included four first permanent molars in good shape, such condition may have not ensured good overall dental health status; primary teeth could have had caries. In Table 1, we had dmft 4.10±3.16, which is considerable. Through resorting to ICDAS II, we were able to identify enamel changes, from minimal color changes indicating demineralization (ICDAS 1 and 2) to carious lesions encompassing small cavities as well as extensive enamel breakdown (ICDAS>2). Most lesions scored were ICDAS 1 and 2, a few ICDAS 3, and none above ICDAS 3.

Pit and fissure sealants can be an effective tool to prevent dental caries and thus help improve oral health of the child population. Our research findings support sealant utilization in one of the prime age groups who can benefit from such a caries prevention approach (-, -, -).

Conclusions

Pit and fissure sealants offer an effective preventive treatment for reducing the incidence of caries over a six-month follow-up period in six to eight years old schoolchildren, regardless of either one of two types of sealants used. In our study, the sealant that proved to be most effective in terms of prevention and retention was Clinpro©3M.