A two-year evaluation of four different fissure sealants.
Abstract: AIM: To evaluate fissure sealants based on Bis-GMA [Fissurit F (FF) and Fissurit FX (FFX)], compomer [Dyract Seal (DS)] and ormocer [Admira Seal (AS)] with respect to retention, marginal integrity and presence of caries after a 2-year period of follow-up. METHODS: 80 children aged 7-13 years (mean age: 9.4 [+ or -] 1.3 years), were included, giving a total of 320 first permanent molars for the study units. Clinical evaluation of the sealants was carried out to assess retention, marginal integrity and presence of caries at 12 and 24 months after initial treatment. RESULTS: Retention of compomer-based DS sealant was significantly lower than that of the others at the 12- and 24-month follow-up examinations (12 month, P<0.000; 24 month, P<0.006). No significant differences between the sealants were observed in marginal integrity (12 month, P>0.473; 24 month, P>0.069) or presence of caries (12 month, P>0.055; 24 month, P>0.777) at any follow-up examination. CONCLUSION: While sealants composed of different resin matrices showed differences in retention, they were similar with respect to marginal integrity and presence of caries. Surface conditioning and the organic structure of the material are factors that may affect sealant retention.

Key words: Sealants, organic structure, filler, retention, caries prevention, marginal integrity
Article Type: Report
Subject: Dental caries (Diagnosis)
Dental caries (Care and treatment)
Sealing compounds (Usage)
Sealing compounds (Health aspects)
Authors: Yilmaz, Y.
Belduz, N.
Eyuboglu, O.
Pub Date: 04/01/2010
Publication: Name: European Archives of Paediatric Dentistry Publisher: European Academy of Paediatric Dentistry Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 European Academy of Paediatric Dentistry ISSN: 1818-6300
Issue: Date: April, 2010 Source Volume: 11 Source Issue: 2
Product: Product Code: 2891000 Adhesives & Sealants; 2891500 Caulking Compounds & Sealants; 2891501 Natural Base Sealants & Caulks; 2891510 Building Caulks & Sealants NAICS Code: 32552 Adhesive Manufacturing SIC Code: 2891 Adhesives and sealants
Geographic: Geographic Scope: Turkey Geographic Code: 7TURK Turkey
Accession Number: 277106734
Full Text: Introduction

Caries diagnosis in the occlusal pit and fissures plays a crucial role for a successful fissure sealant (FS) treatment [Feigal, 1998]. Diagnostic methods for dental caries such as visual-tactile assessment, visual inspection, visual inspection with magnification, laser fluorescence DIAGNOdent and bitewing radiographs have been used [Erten et al., 2006]. Visual inspection may lead to an incorrect treatment decision for teeth with deep pit and fissures and a sharp dental explorer used in the visual-tactile assessment may damage the demineralised areas and lead to implantation of microorganisms [McComb et al., 2001]. Caries of the occlusal enamel may not clearly be visible on radiographs because of the superimposition of the buccal and lingual enamel. However, visual inspection with magnification and DIAGNOdent were able to both increase the sensitivity of diagnosis of caries and were more effective than the other types of examination [Erten et al., 2006].

The composition of FS is important to their success [Feigal, 1998]. Materials such as polyurethane, cyanoacrylate resins, glass ionomer cements, Bis-GMA resins, polyacid-modified composite resins (compomers) and ormocers have been used as FS [Rugg-Gunn, 2001]. Bis-GMA-based FS have been widely used in preventive dentistry [Rugg-Gunn, 2001]. It has been reported that Bis-GMA-based FS have good mechanical properties and are capable of simulating the tooth structure [Manhart et al., 2000]. Bis-GMA-based FS have some disadvantages, such as a low rate of fluoride release, and require an acid conditioning procedure prior to the application of the FS [Kugel, 2000].

Compomer materials have been developed in order to eliminate these disadvantages [Gungor et al., 2004]. The use of a compomer FS with a non-rinse conditioner is able to prevent both contamination of oral tissues and potential disruptive behaviours caused by rinsing of the tooth after acid-etching. Compomers have the desirable mechanical and optical properties of both composite resins and glass-ionomer cements, and release an adequate amount of fluoride [Powers, 2002]. Gungor et al. [2004] found that FSs based on compomer materials and Bis-GMA had similar retention rates; in contrast, Ram et al. [2005] showed that compomer FS had lower rates of success than Bis-GMA-based FS.

In 1998 a new restorative material, ormocer, which is based on silicon dioxide, was introduced to the market [Hickel et al., 1998]. Ormocers, in contrast to resin-based composites, are composed of larger monomer molecules that can reduce the effects of polymerization shrinkage, wear and leaching of monomer (the oestrogenic chemical bisphenol-A) [Arenholt-Bindslev et al., 1999; Bottenberg et al., 2007]. Although several previous studies have evaluated the clinical properties of ormocers when they are used as a restorative material [Tagtekin et al., 2004], no study evaluating the use of ormocers as a FS could be found in the literature. The aim of this study was, therefore, to evaluate the differences between FS based on Bis-GMA, compomer, and ormocer in terms of the criteria of retention, marginal integrity and presence of caries over a 2-year period of follow-up.

Materials and Methods

Study design. This was as a randomized single blind clinical trial to compare the clinical criteria of retention, marginal integrity and presence of caries of sealants based on Bis-GMA, compomer, and ormocer used to seal permanent first permanent molars [FPMs] over a 2-year period. Each child and parent was informed of the protocol of the study, and parental informed consent was obtained before the application of FS.

Subjects. The study participants were 80 healthy children (36 girls, 44 boys), cooperative Frankl score 3 or 4 [Wright, 2000] aged 7 to 13 years (mean age: 9.4 [+ or -] 1.3 years) who were referred to the Paedodontics Department of the Dentistry Faculty, Ataturk University, Turkey. The selection criteria for the study participants were:

* Residence in the same geographical region,

* The absence of bruxism, malocclusion, or allergy to dental resins or latex,

* The presence of fully erupted FPMs with deep and retentive pits and fissures,

* The presence of caries-free FPMs.

The evaluation of caries was performed using an intraoral camera (760,000 pixels, D60204449 RF System, Japan) and a DIAGNOdent device (DiagnoDent, KaVo, Biberach, Germany).

Assessment of teeth. The plaque and debris on the occlusal surfaces were removed using a rotating brush without prophylaxis paste. Images of the teeth were then captured using an intraoral camera and recorded on a computer. Images were evaluated according to the caries criteria of Frances-cut and Lussi [2003] on a 17-inch computer monitor by one previously trained researcher (YY). The scoring system was calibrated using 20 randomly selected teeth chosen within the criteria required for this study. A maximum of 30 sec was allowed for the examination of each tooth. Teeth were then isolated with cotton rolls and assessed in terms of caries by the same researcher (YY) using a DIAGNOdent device. This device was calibrated using a ceramic plate and the tooth surface under investigation. Teeth that showed DIAGNOdent readings of more than 20 as a cut-off point were not included in the study, according to the instructions of the manufacturer. In all 320 FPMs from the 80 participants were included in the study. Although the required sample size was 114 (power analysis=0.80), the study was performed on 320 samples. The number of maxillary and mandibular FPMs in each FS group was equal

Fissure sealant Application. Each tooth was isolated with standard cotton rolls and the occlusal surface was dried. FS with different organic structures as described in Table 1 [two Bis-GMA (FF and FFX), one ormocer (AS) and one compomer (DS)] were applied by two experienced operators. All steps of FS application were performed according to the manufacturer's recommendations. The two Bis-GMA-based FS (40 participants, 160 FPM applications) were applied in a split mouth design. Ormocer-based FS (20 participants, 80 FPM applications) and compomer-based FS (20 participants, 80 FPM applications) were randomly applied. The randomization procedure for the FS was performed using a series of consecutively numbered randomization envelopes.

After the application of FS, occlusion was checked with a carbon marker. Any premature contacts were removed using a round bur. A fluoride varnish was applied to the dematerialized area that had been caused by acid etching. Images of the FS were then captured with the intraoral camera and recorded on the computer.

Fissure sealant evaluation. FS were evaluated clinically by one researcher (YY) with respect to the criteria of retention, marginal integrity and presence of caries at follow-up examinations performed 12 and 24 months after treatment [Gungor et al., 2004]. During the follow-up examinations, images of the FS were captured using the intraoral camera. The marginal integrity of the FS was assessed using a dental explorer. Evaluation of the retention and presence of caries was performed by matching the first and follow-up pictures of the FSs.

Statistical Analysis. The data were analyzed using the SPSS 11.0 statistics program for Windows at the 5% significance level. The difference between the ages of the participants who were treated with different types of FS was analyzed using one-way ANOVA. A chi-square test was used to compare the differences among the four different sealants and to determine which group or groups was responsible for any differences.

All FS were assessed for retention, marginal integrity and presence of caries using the alpha bravo, charlie septom. In this system alpha indicated full retention; bravo some retention and charlie--lost FS. Caries was assessed as alpha--no caries and bravo--caries present

Results

Intra-examiner was reliability calculated for each evaluation criterion using the kappa statistic for intra-examiner reliability it was calculated as 0.80: 0.86 for retention, 0.72 for marginal integrity, and 0.82 for presence of caries. There was no statistically significant difference in the age of the participants among the FS groups (P>0.83). The distribution of the evaluation scores of the FS by time following treatment is shown in Table 2. Table 3 shows the clinical condition of the FS during the follow-up examinations. In all 7 children were lost to the first follow-up: they were either not interested in further participation or had moved abroad. At the end of the last clinical evaluation period, 99 of 292 FS had failed.

There were statistically significant differences between FSs for retention criteria at all follow-up examinations, and the difference was found to be due to the low retention rate of the DS group (Table 2). The differences between FS with respect to both marginal integrity and presence of caries were not statistically significant at any follow-up examination (Table 2).

Discussion

It has been claimed that FS minimize the harmful effects of cariogenic microorganisms on the surface of tooth enamel by producing an effective mechanical barrier against the plaque. This study evaluated the clinical success of 4 FS that contained 3 different resin matrices. Stepped margins of FS contribute to the accumulation of plaque [Ganss et al., 1999], therefore, marginal integrity is an important criterion in the evaluation of FS. In the evaluation of marginal integrity, the differences between FS, that have different organic structures and filler rates have been found to be statistically insignificant. Gungor et al. [2004] demonstrated lower marginal integrity scores for a compomer-based FS when compared with Bis-GMA-based FSs at 12-month follow-up, but similar marginal integrity scores between FS were found at a 24-month follow-up. The latter result was in accordance with our findings. No previous clinical studies have been performed to investigate ormocer-based FS.

Inorganic filler component is another factor that is associated with marginal integrity [Simonsen, 2002]. Although the difference was not significant, the highest alpha score rates for marginal integrity in this study were noted in the low-filled FS (FF). This is in agreement with Koch et al. [1997], who stated that an increase of the inorganic filler rate causes poor marginal adaptation due to a lower wetting ability of the FS.

Although there were no carious lesions on the study teeth at baseline,

caries was detected in 54 of the 292 FPMs during the study. Fractured or partially lost FS leave deep fissures uncovered or a sharp margin that may lead to the formation of caries [Feigal, 1998]. In the present study, FS materials were only applied once and prevention against caries provided by FS decreases over time if they are applied with this regimen [Llodra et al., 1993; Gomez et al., 2005]. There was no statistically significant difference found among the FS for caries. Interestingly, although low retention was noted in the DS group, this group showing similar caries when compared with the other treatment groups at all follow-up examinations. This may be explained in several ways: firstly, while compomer-based materials release an intermediate level of fluoride, Bis-GMA- and ormocer-based FS release only a low level [Kugel, 2000]. Tanaka et al. [1987] have stated that the incorporation of fluoride into the enamel underlying or adjacent to the sealant increases the resistance to demineralisation. Secondly, the antibacterial effect of Prime & Bond NT, the one-step self-etching primer, may contribute to prevention of caries. It has been claimed that the antibacterial effect of dentine bonding systems may be related to their chemical composition or low pH [Baseren et al., 2005]. However, Prime & Bond NT does not contain antibacterial components such as glutaraldehyde and 12-methacryloyloxydodecyl-pyridinium bromide (MDPB). Therefore, the antibacterial effect of Prime & Bond NT could be attributed to its low pH of 1.86, which was calculated in a laboratory medium using a pH/ISE meter (model: 730P, ISTEK, Seoul, Korea).

There was a statistically significant difference between FS for retention. The DS group showed a considerably lower retention rate than other FS. Surface conditioning may have had a significant effect on retention, because a non-rinse conditioning procedure was used in the DS group, following the manufacturer's guidelines. This finding is in agreement with Yakut and Sonmez [2006] and Ram et al. [2005] who reported a low retention rate for DS used with a non-rinse conditioner. Fuks et al. [2002] found that when phosphoric acid was used, the bond strength of a DS FS was much higher than that of NRC + Prime & Bond NT. However, they reported that DS with phosphoric acid showed slightly lower shear bond strength than a Bis-GMA-based sealant. Therefore, another factor that affects FS retention may be the compomer organic structure of DS.

Rock et al. [1990] and later Yildiz et al. [2004] stated that the rate and type of inorganic filler were factors that influenced the retention of FS. However, it appears that the rate and type of filler could not have had an influence on the retention rates of the FS in the present study because FS with different rates and types of inorganic filler showed similar retention rates. In the present study, three (FF, FFX and AS) of the four FS showed similar results with respect to retention, marginal integrity and the presence of caries. The fourth sealant (DS) presented a different result at the 12- and 24-months follow-up examinations with respect to retention criteria.

Visual inspection with magnification and laser fluorescence DIAGNOdent diagnostic systems were used prior to the application of FS to prevent their placement over carious areas. It has been reported that the use of intraoral cameras and the DIAGNOdent diagnostic system can aid clinical decision-making [Erten et al., 2006]. The operators in this study were meticulous in avoiding the placement of FS over carious areas.

The first and follow-up pictures of FS were evaluated according to the criteria of retention and presence of caries to improve the accuracy of the evaluations. However, the evaluations of marginal integrity were performed using visual and tactile assessment, as in previous studies, because the marginal integrity cannot be evaluated from images of the teeth [Gungor et al., 2004]. The DIAGNOdent system was not used for caries detection in the sealed fissures at follow-up examinations because it does not work on opaque FS [Simonsen, 2002]. Although the clear type of DS was used, the DIAGNOdent device was not used for the assessment of caries for this FS to obtain a standardized approach.

This study focused on the clinical effectiveness of FS that have different inorganic filler rates and organic structures when used to seal clinically sound pits and fissures. Further clinical studies are required in order to evaluate sealants that have chemically different resin matrices with respect to the evaluation criteria used in this study.

Conclusion

While fissure sealants with different resin matrices showed differences in retention, there were no difference among sealants with respect to marginal integrity and the presence of caries. Surface conditioning and the organic structure of the sealant may be factors that influence sealant retention.

Acknowledgement:

This research was supported by the Department of Science Research Projects, Ataturk University.

References

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Y. Yilmaz *, N. Belduz *, O. Eyuboglu ** Dept. of Paedodontics, Faculty of Dentistry, Ataturk University, Erzurum, ** Private Practice, Trabzon; Turkey

Postal address: Dr. Y. Yilmaz. Dept. of Paedodontics 25240, Ataturk University, Faculty of Dentistry, Erzurum, Turkey. Email: yyilmaz25@atauni.edu.tr
Table 1: Fissure sealant materials
and applications used in the study

Material/Code         Composition/Colour     Procedure
(Manufacturer)

Vococid               34.5% phosphoric       Application: Apply
(Voco, Cuxhaven,      acid gel               for 60 s, remove by
Germany)                                     using air-water
                                             spray

FF                    Bis-GMA, diurethane    Etching: Used
(Voco, Cuxhaven,      dimethacylate, BHT,    Vococid Application:
Germany)              benzotriazolderivate,  Apply and allow to
                      1.3% sodium            penetrate for 15-
                      fluoride, low filled   20s, then light-
                      (9.5%) /opaque white   cured for 30s

FFX                   Bis-GMA, diurethane    Etching: Used
(Voco, Cuxhaven,      dimetacrylate, BHT,    Vococid Application:
Germany)              benzotriazolderivate,  Apply and allow to
                      1.0% sodium            penetrate for 15-
                      fluoride, highly       20s, then light-
                      filled (55%) /         cured for 30s
                      opaque white

AS                    Three-dimensionally    Etching: Used
(Voco, Cuxhaven,      curing inorganic-      Vococid Application:
Germany)              organic co-polymers    Apply and allow to
                      as well as additive    penetrate for 15-
                      aliphatic and          20s, then light-
                      aromatic               cured for 30s
                      dimethacrylates,
                      highly filled (54%)/
                      opaque white

NRC                   Itaconik and maleic    Application: Apply
(Dentsply De Trey,    acid, water            and leave
Konstanz, Germany)                           undisturbed for 20s
                                             then remove by
                                             blowing gently

Prime-Bond NT         Di and                 Application: Apply
(Dentsply De Trey,    trimethacrylate        for 20s, remove by
Konstanz, Germany)    resins, PENTA, UDMA    blowing gently for
                      resins,                5s
                      photoinitiators,
                      cetylamine
                      hydrofluoride,
                      acetone

DS                    Aminopenta,            Etching: Used NRC
(Dentsply De Trey,    macromonomer, DGDMA,   Application: After
Konstanz, Germany)    aerosil, inhibitor,    Prime-Bond NT was
                      initiators,            applied, DS was
                      strontium-aluminum-    placed immediately
                      fluorosilicate        and light-cured for
                      glass, app. 35%        40s
                      filled /clear

Table 2: The distribution of evaluation scores of
the sealants related to the follow-up periods.

Criteria      Time      Scores       FF        FFX         DS

Retention   12 months    Alpha    19 (29%)   21 (32%)   8 (11%)
                         Bravo    45 (69%)   42 (65%)   60 (80%)
                        Charlie    1 (2%)     2 (3%)     7 (9%)
              Total                  65         65         75

            24 months    Alpha    18 (29%)   14 (22%)    5 (7%)
                         Bravo    39 (63%)   41 (67%)   50 (75%)
                        Charlie    5 (8%)    7 (11%)    12 (18%)
              Total                  62         62         67

Marginal    12 months    Alpha    34 (52%)   29 (44%)   27 (36%)
integrity                Bravo    29 (45%)   35 (54%)   47 (63%)
                        Charlie    2 (3%)     1 (2%)     1 (1%)
              Total                  65         65         75

            24 months    Alpha    31 (50%)   25 (40%)   20 (30%)
                         Bravo    20 (32%)   25 (40%)   38 (57%)
                        Charlie   11 (18%)   12 (20%)   9 (13%)
              Total                  62         62         67

Presence    12 months    Alpha    62 (95%)   64 (99%)   74 (99%)
of caries                Bravo     3 (5%)     1 (1%)     1 (1%)
              Total                  65         65         75

            24 months    Alpha    55 (89%)   52 (84%)   60 (90%)
                         Bravo    7 (11%)    10 (16%)   7 (10%)
              Total                  62         62         67

Criteria        Time          Scores         AS      Chi-square/P

Retention    12 months        Alpha       24 (33%)
                              Bravo       44 (60%)      16.591
                             Charlie       5 (7%)     P<0.011 *
               Total                         73

             24 months        Alpha       17 (25%)
                              Bravo       47 (70%)      15.416
                             Charlie       3 (5%)     P<0.017 *
               Total                         67

Marginal     12 months        Alpha       36 (49%)
integrity                     Bravo       36 (49%)      5.567
                             Charlie       1 (2%)      P>0.473
               Total                         73

             24 months        Alpha       24 (36%)
                              Bravo       37 (55%)      12.269
                             Charlie       6 (9%)      P>0.056
               Total                         67

Presence     12 months        Alpha       66 (90%)      7.758
of caries                     Bravo       7 (10%)      P>0.051
               Total                         73

             24 months        Alpha       58 (86%)      1.099
                              Bravo       9 (14%)      P>0.772
               Total                         67

Significant differences between the groups were
determined with a chi-square test (*P< 0.05
significant difference)--DS values were the reason
of the differences

Table 3: Clinical evaluation of the fissure
sealant materials after 1 and 2 years.

                                                 Lost to
                    Successful     Failed       Follow-up

Sealant             12     24     12     24     12     24
Materials    N     mths   mths   mths   mths   mths   mths

FF           68     62     43     3      19     0      0
FFX          68     62     46     3      16     0      0
DS           80     67     46     8      21     0      0
AS           76     67     58     6      9      0      0
Total       292    258    193     20     65     0      0

Teeth with a Charlie score for the retention or
marginal integrity criteria, or a bravo score for
the presence of caries were evaluated as failed.
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