Comparison of glass-ionomer and resin-based fissure sealants: a 2-year clinical trial

Comparative Evaluation of Wear Strength and Compressive Strength of Two Pit and Fissure Sealants with a Nanofilled Resin Coating: An In Vitro Study

Introduction

The role of sealants for pits and fissures has been emphasized in caries prevention. Considering the advantages of a surface sealer and the effects of its application over restorative materials; the study is aimed at evaluating two pit and fissure sealants with a nanofilled resin coating.

Materials and methods

In this in vitro double-blinded study, a total of 60 caries-free extracted third molars were collected and divided into two groups of 30 each receiving either a resin-based sealant (Helioseal F) or a glass ionomer-based sealant (GC Fuji VII). Each sample was then applied with GCoat Plus surface sealer. 15 samples each containing GC Fuji VII and 15 containing Helioseal F were then subjected to wear. Another 15 samples of GC Fuji VII and 15 of Helioseal F were subjected to compressive load.

Results

On assessing the wear strength, the weight loss in group I (resin sealant with surface sealer) was 1.73 ± 0.50 (μg) which was statistically significant (p = 0.023). There was no significant difference in comparing the wear depth between both groups. There was a high statistically significant difference when assessing the compressive strength, group II (glass ionomer sealant with surface sealer) had 3566.4 ± 757 (μm) when compared to group I (resin sealant with surface sealer) 1568.53 ± 680 (p ≤ 0.01).

Conclusion

Sealants are known for their poor retention and keeping that in mind we designed this study to evaluate the physical properties of sealants with a resin coating over them. Within the limitations of this study, the conclusions are glass ionomer sealant showed greater resistance to wear when compared to the resin-based sealant and the resin-based sealant showed higher compressive strength values than the glass ionomer sealant.

How to cite this article

Gunasekaran R, Sharmin D, Baghkomeh PN, et al. Comparative Evaluation of Wear Strength and Compressive Strength of Two Pit and Fissure Sealants with a Nanofilled Resin Coating: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(1):31-35.

Twelve-month clinical evaluation of retention of resin-based sealant on first permanent molars

INTRODUCTION

The majority of researchers agree that sealants need to be monitored and kept in good condition because even a small amount of sealant loss raises the possibility of developing caries lesions. The first year after application is when sealant loss is reported to be at its highest. This motivated us to monitor silanized patients who received resin-based sealant for a full year.

Penetration and Adaptation of the Highly Viscous Zinc-Reinforced Glass Ionomer Cement on Contaminated Fissures: An In Vitro Study with SEM Analysis

Objective: To evaluate the penetration and adaptation of highly viscous zinc-reinforced glass ionomer cement (ZRGIC), using a scanning electron microscope (SEM), when applied under various contaminated conditions on grooves and fissures of primary second molars. Materials and Methods: A total of 40 extracted human primary second molars were randomly assigned into five groups (8 teeth each), with different surface conditions (conditioned with 40% polyacrylic acid, dry condition, water contamination, saliva contamination, or saliva contamination and air-drying) on the occlusal surface before placement of zinc-reinforced highly viscous glass ionomer cement with the finger-press technique. After sectioning the teeth, they were subjected to SEM analysis, where four in each group underwent aging by thermocycling and the other four were without aging. ANOVA tests, post hoc analysis, and unpaired t-tests were used for statistical analyses. Results: There was a significant statistical difference in the sealant penetration in the non-aging group, but in the aging group, there was no significant statistical difference in the sealant penetration. On other hand, a significant statistical difference was found in the adaptation between all the groups (p < 0.05). Highly viscous zinc-reinforced glass ionomer fissure sealants have better fissure penetration and more intimate adaptation under fissures conditioned with 40% polyacrylic acid and dry surface fissures with no contamination. However, the best penetration and retention after aging were under contaminated fissures with a shiny layer of saliva. Conclusions: The ZRGIC is a highly viscous fluoride-releasing cement, effectively seals fissures by interfering with food lodgment and protecting teeth from caries. It is advisable to restore the fissures with the minimal technique of sensitive fluoride-releasing GIC, particularly in young, uncooperative children, rather than leaving a caries-prone environment.

Performance of fissure sealants on fully erupted permanent molars with incipient carious lesions: A glass-ionomer-based versus a resin-based sealant

Background. The effectiveness of fissure sealants in caries prevention depends on their long-term retention and ability to stop caries progression. This randomized controlled clinical trial compared the retention rate and cariostatic properties of a contemporary glass-ionomer-based sealant (GIS) versus a resin-based sealant (RS) placed on fully erupted permanent molars in a split-mouth design. Methods. The sealants were placed on fully erupted permanent teeth (8‒12 years of age) in 45 children. The evaluation was conducted after one week and three and six months. Results. There was a statistically significant difference in the retention rate and caries transition between the two groups over a six-month clinical evaluation period. The resin-based sealant group showed a better retention rate than the GIS group (75.56% and 48.88%, respectively). The resin-based sealant was superior to GIS in preventing caries progression. Conclusion. Resin-based fissure sealant with fluoride releasing properties might be preferable in preventing caries progression of incipient non-cavitated carious lesions in fully-erupted teeth.

Meta-analysis of the longevity of commonly used pit and fissure sealant materials

OBJECTIVE

This systematic literature review and meta-analysis compared the clinical retention of primed or adhesively bonded sealants to that of conventional sealant materials.

METHODS

A search of the MEDLINE, EMBASE and CENTRAL databases identified 3707 abstracts published prior to 12/31/2017, of which 335 clinical publications were analysed in detail. A total of 67 studies included information about sealant retention after 24, 36, or 60 months of follow-up. A meta-analysis using a random effects model was conducted to calculate the pooled estimate of the retention rates for the five groups of sealants. Subgroup moderator analysis was performed to compare the pooled retention rate estimate (RRE) of primed sealants against those of the other groups.

RESULTS

Primed sealants had a 2-year pooled RRE of 43.2% (95% CI: 30.5-55.8), which was significantly inferior to those of auto-polymerizing (80.8%, 95% CI: 72.2-89) and light-polymerizing sealants (68.4%, 95% CI: 60.2-76.7). Fluoride-releasing and light-polymerizing sealants had the highest 3-year pooled RREs (86.4%, 95% CI: 73.4-99.3 and 83.1%, 95% CI: 75.6-90.7, respectively).

SIGNIFICANE

The results of this meta-analysis suggest that primed sealants cannot be fully recommended for clinical practice due to their moderate survival rates. Auto-polymerizing, light-polymerizing and fluoride-releasing sealants continue to be considered the reference standards for pit and fissure sealants. However, future generations and developments of primed sealant materials may change this position.

Chemical and biological properties of new sealant-use cement materials

OBJECTIVES

The aim of this study was to investigate the chemical and biological properties of newly developed bioactive cements, modified such that they are largely composed of calcium, phosphate and fluoride. We investigated whether newly developed bioactive cements have the potential to further protect surrounding hard tissue and enhance remineralization of demineralized tissue by additional ion release.

METHODS

We developed four types of novel GIC based on Fuji VII, modified with phosphate and fluoride and calcium. Compressive strength tests were performed following JIS T6607 methods. Ion release of calcium, phosphate and fluoride after 24 h storage were determined using atomic absorption spectroscopy, colorimetry and an ion-specific electrode. Fluoride releases and recharge were measured at 1, 3, 6, 12, 24 and 168 h. Viability was determined by colony-forming units. Inhibitions of biofilm formation and cell proliferation activity were measured.

RESULTS

The GIC groups showed no significant differences in compressive strength after 1 and 7 days. The rates of fluoride ion release from newly developed GICs were significantly greater than those of Fuji VII, Fuji III and BS. All materials except TM can be recharged with fluoride ions. Compared with the control group, which did not release fluoride ions, all materials showed significantly stronger antibacterial effects. The newly developed GICs and BS showed less biofilm formation than Fuji VII and Fuji III.

SIGNIFICANCE

Three of four newly developed GICs modified with calcium, phosphate and fluoride ions were found to be superior to other sealant materials.

Glass ionomer cements as fissure sealing materials: yes or no?: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to evaluate the ability of glass ionomer cements (GICs) and resin-based sealants (RBSs) to prevent the occurrence of caries and their retention in standards-based clinical studies.

TYPES OF STUDIES REVIEWED

The authors conducted a literature search (from database inception through September 20, 2017) to identify studies for inclusion in this systematic review. The authors assessed the quality of the evidence with the modified Jadad scale and performed the meta-analysis by using a random-effects model.

RESULTS

The authors considered 20 studies on caries prevention and 28 studies on retention that met the inclusion criteria for the meta-analysis. The results of the meta-analysis for caries development showed no significant difference (odds ratio, 0.938; 95% confidence interval, 0.647 to 1.359; P = .734). However, the result for the retention rate showed the advantage of RBSs (odds ratio, 6.006; 95% confidence interval, 3.226 to 11.183; P = .000).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

There was no difference between the percentage of caries development with use of GICs as fissure sealing material compared with that for the conventional RBSs, but the retention rate of conventional RBSs was much higher than that of the GICs.

Pit and fissure sealants for preventing dental decay in permanent teeth

BACKGROUND

Dental sealants were introduced in the 1960s to help prevent dental caries, mainly in the pits and fissures of occlusal tooth surfaces. Sealants act to prevent bacteria growth that can lead to dental decay. Evidence suggests that fissure sealants are effective in preventing caries in children and adolescents compared to no sealants. Effectiveness may, however, be related to caries incidence level of the population. This is an update of a review published in 2004, 2008 and 2013.

OBJECTIVES

To compare the effects of different types of fissure sealants in preventing caries in occlusal surfaces of permanent teeth in children and adolescents.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched: Cochrane Oral Health's Trials Register (to 3 August 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 7), MEDLINE Ovid (1946 to 3 August 2016), and Embase Ovid (1980 to 3 August 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials to 3 August 2016. No restrictions were placed on language or date of publication.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing sealants with no sealant or a different type of sealant material for preventing caries of occlusal surfaces of premolar or molar teeth in children and adolescents aged up to 20 years. Studies required at least 12 months follow-up. We excluded studies that compared compomers to resins/composites.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, extracted data and assessed risk of bias of included studies. We presented outcomes for caries or no caries on occlusal surfaces of permanent molar teeth as odds ratio (OR) or risk ratio (RR). We used mean difference (MD) for mean caries increment. All measures were presented with 95% confidence intervals (CI). We conducted meta-analyses using a random-effects model for comparisons where there were more than three trials; otherwise we used the fixed-effect model. We used GRADE methods to assess evidence quality.

MAIN RESULTS

We included 38 trials that involved a total of 7924 children; seven trials were new for this update (1693 participants). Fifteen trials evaluated the effects of resin-based sealant versus no sealant (3620 participants in 14 studies plus 575 tooth pairs in one study); three trials with evaluated glass ionomer sealant versus no sealant (905 participants); and 24 trials evaluated one type of sealant versus another (4146 participants). Children were aged from 5 to 16 years. Trials rarely reported background exposure to fluoride of trial participants or baseline caries prevalence. Resin-based sealant versus no sealant: second-, third- and fourth-generation resin-based sealants prevented caries in first permanent molars in children aged 5 to 10 years (at 24 months follow-up: OR 0.12, 95% CI 0.08 to 0.19, 7 trials (5 published in the 1970s; 2 in the 2010s), 1548 children randomised, 1322 children evaluated; moderate-quality evidence). If we were to assume that 16% of the control tooth surfaces were decayed during 24 months of follow-up (160 carious teeth per 1000), then applying a resin-based sealant would reduce the proportion of carious surfaces to 5.2% (95% CI 3.13% to 7.37%). Similarly, assuming that 40% of control tooth surfaces were decayed (400 carious teeth per 1000), then applying a resin-based sealant would reduce the proportion of carious surfaces to 6.25% (95% CI 3.84% to 9.63%). If 70% of control tooth surfaces were decayed, there would be 19% decayed surfaces in the sealant group (95% CI 12.3% to 27.2%). This caries-preventive effect was maintained at longer follow-up but evidence quality and quantity was reduced (e.g. at 48 to 54 months of follow-up: OR 0.21, 95% CI 0.16 to 0.28, 4 trials, 482 children evaluated; RR 0.24, 95% CI 0.12 to 0.45, 203 children evaluated). Although studies were generally well conducted, we assessed blinding of outcome assessment for caries at high risk of bias for all trials (blinding of outcome assessment is not possible in sealant studies because outcome assessors can see and identify sealant). Glass ionomer sealant versus no sealant: was evaluated by three studies. Results at 24 months were inconclusive (very low-quality evidence). One sealant versus another sealant: the relative effectiveness of different types of sealants is unknown (very low-quality evidence). We included 24 trials that directly compared two different sealant materials. Comparisons varied in terms of types of sealant assessed, outcome measures chosen and duration of follow-up. Adverse events: only four trials assessed adverse events. No adverse events were reported.

AUTHORS' CONCLUSIONS

Resin-based sealants applied on occlusal surfaces of permanent molars are effective for preventing caries in children and adolescents. Our review found moderate-quality evidence that resin-based sealants reduced caries by between 11% and 51% compared to no sealant, when measured at 24 months. Similar benefit was seen at timepoints up to 48 months; after longer follow-up, the quantity and quality of evidence was reduced. There was insufficient evidence to judge the effectiveness of glass ionomer sealant or the relative effectiveness of different types of sealants. Information on adverse effects was limited but none occurred where this was reported. Further research with long follow-up is needed.

Glass ionomer ART sealant and fluoride-releasing resin sealant in fissure caries prevention--results from a randomized clinical trial

Background

The relative performance of ART sealant and fluoride-releasing resin sealant in preventing fissure caries in permanent molars was compared in a randomized clinical trial conducted in southern China (ClinicalTrials.gov NCT01829334).

Methods

After obtaining ethical approval, healthy schoolchildren who had permanent first molars with occlusal fissures which were sound but deep or presented with only incipient caries were recruited for the study. Included molars were randomly allocated into one of four parallel study groups in units of left/right teeth per mouth. Two of the four groups adopted the methods of ART or fluoride-releasing resin sealant placement while the other two groups adopted the topical fluoride application methods. Fissure status of the molars in each group was evaluated every 6 months. Development of dentine caries and sealant retention over 24 months in the molars in the two sealant-using groups was compared in this report. Outcome on cost-effectiveness of all four groups over 36 months will be reported elsewhere.

Results

At baseline, a total of 280 children (383 molars) with mean age 7.8 years were involved for the two sealant groups. After 24 months, 261 children (357 molars) were followed. Proportions of molars with dentine caries were 7.3% and 3.9% in the ART sealant and fluoride-releasing resin sealant groups, respectively (chi-square test, p = 0.171). Life-table survival analysis showed that sealant retention (full and partial) rate over 24 months for the resin sealant (73%) was significantly higher than that (50%) for the ART sealant (p < 0.001). Molar survival (no development of dentine caries) rates in the ART sealant (93%) and fluoride-releasing resin sealant (96%) groups were not significantly different (p = 0.169). Multilevel logistic regression (GEE modeling) accounting for the effects of data clustering and confounding factors confirmed this finding.

Conclusions

Though the retention of fluoride-releasing resin sealant was better than that of the ART sealant, their effectiveness in preventing fissure caries in permanent molars did not differ significantly over 24 months. ART sealants could be a good alternative when and where resources for resin sealant placement are not readily available.

The success rates of a glass ionomer cement and a resin-based fissure sealant placed by fifth-year undergraduate dental students

AIM

To evaluate retention and caries prevention of a glass-ionomer cement (GIC) and a resin-based fissure sealant placed by fifth-year undergraduate dental students.

METHODS

The study was conducted according to a split-mouth, randomised clinical trial. Children with at least one pair of caries-free permanent first molars with deep pits and fissures were included in the study. The children were selected from a population that had a high risk for dental caries. Sealant materials were applied by fifth-year undergraduate dental students on 346 fissures of the first permanent molars in 173 children. The ages of the children ranged from 7-15 years (mean 9.4). Two researchers at the clinics supervised all of the procedures. Intra-examiner reproducibility and inter-examiner reproducibility were 0.90 and 0.86, respectively, for the clinical assessment of sealant retention and caries evaluation.

RESULTS

GIC sealants were completely lost in 31.9% and resin-based sealants in 16.6% (p<0.05). The total retention rates of GIC sealants and resin-based sealants were 13.8% and 20.8%, respectively. After 24 months, the caries increment was 3.4% for GIC sealants and 4.8% for resin-based sealants (p>0.05).

CONCLUSIONS

The retention of GIC sealants was markedly inferior to the retention of resin-based sealants; however, GIC when used as a pit and fissure sealant was slightly more effective in preventing occlusal caries.

Sealants for preventing dental decay in the permanent teeth

BACKGROUND

Dental sealants were introduced in the 1960s to help prevent dental caries in the pits and fissures of mainly the occlusal tooth surfaces. Sealants act to prevent the growth of bacteria that can lead to dental decay. There is evidence to suggest that fissure sealants are effective in preventing caries in children and adolescents when compared to no sealants. Their effectiveness may be related to the caries prevalence in the population.

OBJECTIVES

To compare the effects of different types of fissure sealants in preventing caries in permanent teeth in children and adolescents.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 1 November 2012); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 7); MEDLINE via OVID (1946 to 1 November 2012); EMBASE via OVID (1980 to 1 November 2012); SCISEARCH, CAplus, INSPEC, NTIS and PASCAL via STN Easy (to 1 September 2012); and DARE, NHS EED and HTA (via the CAIRS web interface to 29 March 2012 and thereafter via Metaxis interface to September 2012). There were no language or publication restrictions. We also searched for ongoing trials via ClinicalTrials.gov (to 23 July 2012).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of at least 12 months duration comparing sealants for preventing caries of occlusal or approximal surfaces of premolar or molar teeth with no sealant or different type of sealant in children and adolescents under 20 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, extracted data and assessed trial quality. We calculated the odds ratio (OR) for caries or no caries on occlusal surfaces of permanent molar teeth. For trials with a split-mouth design, the Becker-Balagtas odds ratio was used. For mean caries increment we used the mean difference. All measures are presented with 95% confidence intervals (CI). The quality of the evidence was assessed using GRADE methods. We conducted the meta-analyses using a random-effects model for those comparisons where there were more than three trials in the same comparison, otherwise the fixed-effect model was used.

MAIN RESULTS

Thirty-four trials are included in the review. Twelve trials evaluated the effects of sealant compared with no sealant (2575 participants) (one of those 12 trials stated only number of tooth pairs); 21 trials evaluated one type of sealant compared with another (3202 participants); and one trial evaluated two different types of sealant and no sealant (752 participants). Children were aged from 5 to 16 years. Trials rarely reported the background exposure to fluoride of the trial participants or the baseline caries prevalence.- Resin-based sealant compared with no sealant: Compared to control without sealant, second or third or fourth generation resin-based sealants prevented caries in first permanent molars in children aged 5 to 10 years (at 2 years of follow-up odds ratio (OR) 0.12, 95% confidence interval (CI) 0.07 to 0.19, six trials (five published in the 1970s and one in 2012), at low risk of bias, 1259 children randomised, 1066 children evaluated, moderate quality evidence). If we were to assume that 40% of the control tooth surfaces were decayed during 2 years of follow-up (400 carious teeth per 1000), then applying a resin-based sealant will reduce the proportion of the carious surfaces to 6.25% (95% CI 3.84% to 9.63%); similarly if we were to assume that 70% of the control tooth surfaces were decayed  (700 carious teeth per 1000), then applying a resin-based sealant will reduce the proportion of the carious surfaces to 18.92% (95% CI 12.28% to 27.18%). This caries preventive effect was maintained at longer follow-up but both the quality and quantity of the evidence was reduced (e.g. at 48 to 54 months of follow-up OR 0.21, 95% CI 0.16 to 0.28, four trials (two studies at low risk of bias and two studies at high risk of bias), 482 children evaluated; risk ratio (RR) 0.24, 95% CI 0.12 to 0.45, one study at unclear risk of bias, 203 children evaluated).- Glass ionomer sealant compared with no sealant: There is insufficient evidence to make any conclusions about whether glass ionomer sealants, prevent caries compared to no sealant at 24-month follow-up (mean difference in DFS -0.18, 95% CI -0.39 to 0.03, one trial at unclear risk of bias, 452 children randomised, 404 children evaluated, very low quality evidence).- Sealant compared with another sealant: The relative effectiveness of different types of sealants remained inconclusive in this review. Twenty-one trials directly compared two different sealant materials. Several different comparisons were made according to type of sealant, outcome measure and duration of follow-up. There was great variation with regard to comparisons, outcomes, time of outcomes reported and background fluoride exposure if this was reported.Fifteen trials compared glass ionomer with resin sealants and there is insufficient evidence to make any conclusions about the superiority of either of the two materials. Although there were 15 trials the event rate was very low in many of these which restricted their contribution to the results.Three trials compared resin-modified glass ionomer with resin sealant and reported inconsistent results.Two small low quality trials compared polyacid-modified resin sealants with resin sealants and found no difference in caries after 2 years.- Adverse effects: Only two trials mentioned adverse effects and stated that no adverse effects were reported by participants.

AUTHORS' CONCLUSIONS

The application of sealants is a recommended procedure to prevent or control caries. Sealing the occlusal surfaces of permanent molars in children and adolescents reduces caries up to 48 months when compared to no sealant, after longer follow-up the quantity and quality of the evidence is reduced. The review revealed that sealants are effective in high risk children but information on the magnitude of the benefit of sealing in other conditions is scarce. The relative effectiveness of different types of sealants has yet to be established.

A 1-year clinical evaluation of fissure sealants on permanent first molars

Objective:

To evaluate and compare the retention, marginal discoloration, surface texture and anatomical form of pit and fissure sealants.

Materials and Methods:

Thirty children between the ages of 6 and 10 years, who were attending the school health program regularly, had participated in the study. A split-mouth design was used in which the two fissure sealants (Helioseal-F and Glass ionomer Fuji VII) were randomly placed in 60 matched contralateral pairs of permanent molar teeth. Sealants were rated by a single trained and calibrated examiner using mouth mirrors and probes following the US Public Health Service criteria. The sealants were evaluated at 3 months, 6 months and 1 year intervals.

Results:

The data obtained for retention, marginal discoloration, surface texture and anatomical form of pit and fissure sealants were tabulated and compared statistically using the Chi-square test of significance.

Conclusion:

The Helioseal-F sealant was better than the Glass ionomer Fuji VII sealant with respect to retention, anatomical form and surface texture. Both the materials showed similar results with respect to marginal discoloration.

Twenty-four month clinical evaluation of fissure sealants on partially erupted permanent first molars: glass ionomer versus resin-based sealant

BACKGROUND

Glass ionomer sealants are an alternative to resin-based sealants, especially for use in partially erupted permanent molars. The authors conducted a study to compare the retention, marginal staining and cariostatic properties of a glass ionomer sealant with those of a resin-based sealant during a 24-month period.

METHODS

We included in this study 39 patients aged 5 through 9 years who had bilateral partially erupted first permanent molars. One of us (S.B.) placed a resin-based sealant (Delton Plus FS+, Dentsply Professional, York, Pa.) (group D) on a partially erupted first molar in one quadrant of the maxilla or mandible and a glass ionomer sealant (GC Fuji Triage White, GC America, Alsip, Ill.) (group T) in the other quadrant. Two masked and calibrated investigators (S.A.A., J.C.) evaluated the sealants for retention, marginal staining and carious lesions at three, six, 12 and 24 months. The authors used a multinomial regression for statistical analysis (P < .05).

RESULTS

The recall rate was 69.2 percent at 24 months. Two sealants from group D and three from group T were lost completely. Complete retention rates at 24 months were 40.7 and 44.4 percent for groups D and T, respectively. The authors found no statistically significant difference in retention rates between groups at each recall examination (P > .05). For marginal staining, sealants in the resin-based group exhibited statistically higher marginal staining than did sealants in the glass ionomer group (P < .05). Although the authors detected no caries in teeth in group T, teeth in group D in which the sealant was lost completely experienced demineralization.

CONCLUSIONS

Resin-based and glass ionomer sealants exhibited similar retention rates at 24 months. However, marginal staining was lower in the glass ionomer group, and the authors found no caries in teeth in this group. Consequently, glass ionomer sealants may be a better choice when salivary contamination is expected.

CLINICAL IMPLICATIONS

Sealing during tooth eruption presents a particular challenge owing to difficulty in isolating the tooth. Glass ionomers may be a better material for sealing partially erupted molars.

Caries-preventive effect of glass ionomer and resin-based fissure sealants on permanent teeth: An update of systematic review evidence

Background

This article constitutes a partial update of the original systematic review evidence by Yengopal et al. from 15 January 2008 (published in the Journal of Oral Science in 2009) with primary focus on research quality in regard to bias risk in trials. Its aim is to update the existing systematic review evidence from the English literature as to whether caries occurrence on pits and fissures of teeth sealed with either GIC or resin is the same.

Methods

In addition to the 12 trials included during the original systematic review, 5 new trials were identified during the database search (up to 26 August 2010) and 2 further trials were included from a hand search and reference check. Of these, 3 trials were excluded and 16 were accepted for data extraction and quality assessment. The quality of accepted trials was assessed, using updated quality criteria, and the risk of bias was investigated in more depth than previously reported. In addition, the focus of quantitative synthesis was shifted to single datasets that were extracted from the accepted trials.

Results

Twenty-six dichotomous and 4 continuous datasets were extracted. Meta-analysis and cumulative meta-analysis were used in combining clinically homogenous datasets. The overall outcome of the computed datasets suggest no difference between the caries-preventive effects of GIC- and resin-based fissure sealants.

Conclusions

This overall outcome is in agreement with the conclusions of the original systematic review. Although the findings of the trials identified in this update may be considered to be less affected by attrition- and publication bias, their risk of selection- and detection-/performance bias is high. Thus, verification of the currently available results requires further high quality randomised control trials.

Comparison of caries prevention with glass ionomer and composite resin fissure sealants

BACKGROUND/PURPOSE

Atraumatic restorative treatment (ART) was developed primarily for use in underserved areas of the world. This study was designed to compare caries prevention with high-viscosity glass ionomer cement (GIC) sealants placed according to the ART procedure and light-cured composite resin sealants after 3 years.

METHODS

The study was conducted in a boarding school in the city of Kirikkale. Four experienced dentists placed a total of 207 sealants (91 GIC and 116 composite resin), without chair-side assistance, on the school premises.

RESULTS

A total of 137 sealants were available after 3 years. 55.3% of the GIC and 93.8% of the composite resin sealants were lost completely, and the difference between the two groups was statistically significant. Only six of 56 teeth in the GIC group and eight of 81 in the composite resin group showed caries.

CONCLUSION

Under field conditions in which moisture control was not effective, a high-viscosity and less technique-sensitive glass ionomer material can be used as an effective sealant material, rather than resin.

Pit and fissure sealants for preventing dental decay in the permanent teeth of children and adolescents

BACKGROUND

Although pit and fissure sealants are effective in preventing caries, their efficacy may be related to the caries prevalence in the population.

OBJECTIVES

The primary objective of this review was to evaluate the caries prevention of pit and fissure sealants in children and adolescents.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group Trials Register, CENTRAL (The Cochrane Library 2007, Issue 3) and MEDLINE (to October 2007); EMBASE (to June 2007); SCISEARCH, CAplus, INSPEC, NTIS, PASCAL, DARE, NHS EED and HTA (to February 2008). There were no language or publication restrictions.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of at least 12 months in duration comparing sealants with no sealant or sealants from different classes of materials for preventing occlusal caries in children and adolescents under 20 years. The primary outcome was the increment in the numbers of carious occlusal surfaces of premolars and molars.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, extracted data and quality assessed trials. Risk ratios (RR) were calculated for differences between intervention and control groups and in split-mouth studies for differences of paired tooth surfaces being carious or not. The meta-analyses were conducted using a random-effects model.

MAIN RESULTS

Sixteen studies were included in the review; 7 studies provided data for comparison of sealant versus control without sealant and 10 studies for comparison of sealant versus sealant. Five split-mouth studies and one parallel group study with 5 to 10 year old children found a significant difference in favour of second or third generation resin-based sealants on first permanent molars, compared to a control without sealant, with a pooled RR of 0.13 (95% confidence interval (CI) 0.09 to 0.20), 0.22 (95% CI 0.15 to 0.34), 0.30 (95% CI 0.22 to 0.40), and 0.40 (95% CI 0.31 to 0.51) at 12, 24, 36 and 48-54 months follow up, respectively. Further, one of those studies with 9 years of follow up found significantly more caries in the control group compared to resin sealant group; 27% of sealed surfaces were decayed compared to 77% of surfaces without sealant.The results of the studies comparing different sealant materials were conflicting.

AUTHORS' CONCLUSIONS

Sealing is a recommended procedure to prevent caries of the occlusal surfaces of permanent molars. The effectiveness of sealants is obvious at high caries risk but information on the benefits of sealing specific to different caries risks is lacking.

Heat-treated glass ionomer cement fissure sealants: retention after 1 year follow-up

OBJECTIVE

The aim of this study was to assess the retention rate of glass ionomer cement (GIC) fissure sealants heated during setting time.

METHODS

One hundred and twelve teeth with well-delineated fissure morphology were sealed with composite resin and GIC. Composite resin (Helioseal F, Vivadent) was used in control group A (56 teeth). GIC (Fuji VII, GC) was applied using split-mouth design with conditioning in group B (26 teeth) and without surface conditioning in group C (30 teeth). GIC was heated with external heat source (Elipar Trilight, Espe) for 40 s during the setting time according to the manufacturer's instructions. Fissure sealants were evaluated 1 year after clinical service.

RESULTS

Retention rate in group A was 80.4% after 1 year of clinical service. Group B showed retention rate of 30.8%, and group C of 26.7%. Two new caries lesions were detected in groups B and C. Significant differences in retention between the composite group and GIC groups were obtained by Kruskal-Wallis and Mann-Whitney tests.

CONCLUSION

It could be concluded that retention rate of GIC sealing treated with heat during setting time was significantly lower than retention of conventional composite resin. The heating procedure during setting of GIC sealants cannot be recommended as routine treatment in clinical practice.

Effects of composite fissure sealants on IR laser fluorescence measurements

The influence of composite fissure sealants on caries detection with IR laser fluorescence measurements should be assessed. Thirty-five extracted human teeth with 105 initial carious lesions were included. Six groups containing 15 lesions each were sealed with either a clear or a white version of three sealants. Group 7 was sealed with an experimental nanofilled material. Occlusal surfaces were irradiated by a diode laser (<1 mW, 655 nm). Fluorescence was measured before and after acid etching, directly and 1 week after application of the sealants. Values significantly increased after etching (p < 0.05). Compared to initial measurements, values decreased after sealing with the white materials (p < 0.05). There was no difference between values before and after sealing with the clear and the experimental materials (p > 0.05). All values were reproducible. The study indicates that it might be possible to monitor caries activity under clear or nanofilled fissure sealants by means of laser fluorescence.

Caries-preventive effect of resin-based and glass ionomer sealants over time: a systematic review

INTRODUCTION

The difference in preventing dentine lesion development between resin-based and glass ionomer sealant materials is unclear. Two recently published reviews were unable to conclude on the difference because the comparison was an exclusion criterion in one review and there were statistical shortcomings in the relevant papers in the other (Cochrane) review.

OBJECTIVES

The aim of the present investigation was to carry out a systematic review on the caries-preventive effect of these two types of sealant materials under more liberal exclusion criteria concerning the statistical presentations in the publications.

METHODS

Based on five exclusion criteria, the literature search in the electronic libraries PubMed and MEDLINE and the publications retrieved in the Cochrane review, revealed 12 eligible publications for analyses. A variety of glass ionomers and resin-based sealant materials had been applied in the included studies. Attributable risk (AR) was chosen rather than relative risk (RR), as used in the Cochrane review, because RR is very instable in a low caries population.

RESULTS

There was no consistent pattern observed with respect to the caries-preventive effect of either resin-based or glass ionomer sealants. Therefore, it was impossible to calculate an overall AR.

CONCLUSIONS

There is no evidence that either resin-based or glass ionomer sealant material is superior to the other in preventing dentine lesion development in pits and fissures over time.

Effects of a glass-ionomer cement on the remineralization of occlusal caries--an in situ study

This work evaluated the remineralization of demineralized enamel of pits and fissures of human third molars sealed with a glass ionomer cement (Fuji IX, GC Corporation--Japan) or with a Bis-GMA sealant (Delton--Dentsply). Ten volunteers participated in this in situ study that consisted of two thirty-day periods using intra-oral devices, with a weeks interval in between. Four experimental treatment procedures and one control were randomly assigned to the volunteers specimens: Group I, no treatment, control; Group II, artificial caries process; Group III, same treatment as Group II, but sealed with Delton (Dentsply); Group IV, same treatment as Group II, but sealed with Fuji IX (GC Corporation--Japan); Group V, same treatment as Group II and no sealing. Groups I and II were not submitted to the oral environment and served as controls. After a period of 30 days in the oral environment, the specimens were removed from the devices, embedded in acrylic resin, ground flat and polished. Then, Knoop hardness tests were performed, with a 25 g static load applied for 15 seconds. The measurements were made from the base of the fissure up to an opening of 600 microm, pre-established between the inclines of the cusps. Three indentations were then made, located at 25, 75, and 125 microm in depth from the outer enamel margin and 100 microm apart from each other (Micromet 2003). The Brieger F and Bonferronis tests were applied to the measurements. It was concluded that sealing with the glass ionomer cement Fuji IX was capable of making the enamel of pits and fissures more resistant by increasing the value of Knoop hardness.

Compressive Strength, Surface Roughness, Fluoride Release and Recharge of Four New Fluoride-releasing Fissure Sealants

The aim of this study was to investigate the compressive strength and surface roughness of two glass ionomer cements and two resin-based fissure sealants before and after fluoride release and recharge. Twenty-one specimens were prepared and divided into three groups for each material. First group was loaded in compression until failure. Fluoride released was measured from the remaining specimens, and then the second group of seven specimens was loaded at 28th day. The remaining seven specimens were exposed to 0.05% NaF solution and 1.23% APF gel. Fluoride amount was measured, and the last group was loaded at 70th day. Surface roughness measurement of five more disk-shaped specimens from each material was also carried out. After exposure to APF gel, all materials were recharged. At the end of experimental period, it was found that surface roughness increased, whereas compressive strength decreased, over time. In conclusion, fluoride-releasing fissure sealants could act as show, rechargeable fluoride release systems. However, if a fissure sealant exhibited high fluoride release, it had inferior mechanical properties.

Retention of resin-based pit and fissure sealants: A systematic review

The aim of the present study was to perform a systematic review on the retention of resin-based sealants (RBSs) according to the material used and the clinical procedure. An electronic search in MEDLINE, EMBASE, Cochrane library and SCOPUS was completed by a hand search in conference proceedings. One hundred and twenty-four studies were identified, 31 of which were included. The retention rate of auto-polymerized and light-cured RBSs did not differ significantly. Light-cured RBSs had a significantly higher retention rate than fluoride-containing light-cured RBSs at 48 months (RR = 0.80, 95% CI: 0.72-0.89) and more. Concerning the clinical procedure, the scarcity of well-conducted studies made judgement difficult, except for the isolation stage. If using a rubber dam did not affect retention of auto-polymerized RBSs, it did for fluoride-containing light-cured RBSs (RR = 2.03, 95% CI: 1.51-2.73).

A field trial of resin-based and glass-ionomer fissure sealants: clinical and radiographic assessment of caries

OBJECTIVE

The purpose of the present study was to provide further data for comparison of retention and caries-preventive effect of a resin-based sealant (Delton, and a glass-ionomer sealant (Fuji III).

METHODS

The study was conducted in the municipality of Vaerløse located 15 km north of Copenhagen, Denmark in the period 1996-2001. The study comprised 153 children aged 8-13 years with a total of 364 site-pairs. Caries was diagnosed both clinically and radiographically, and sealant retention was diagnosed clinically. Sealants were placed either by one of four dentists, who had the responsibility for the children's dental care, by a dental hygienist or a dental assistant. Mean follow-up time was 38-39 months for sites on first permanent molars and 28-29 months for sites on second permanent molars.

RESULTS

The retention rates were consistently, and considerably lower for Fuji III than for Delton. Relative risks of caries in Delton-sealed teeth over Fuji III-sealed teeth was 0.435 (95% CI 0.150-0.846) based on the clinical diagnosis, and 0.559 (95% CI 0.342-0.905) based on the radiographic diagnosis. The ratio of the relative risks (clinical over radiographic diagnosis) was close to 1 (0.778; 95% CI 0.272-1.481).

CONCLUSION

In the present study, Delton-sealed teeth had a lower risk than Fuji III-sealed teeth of developing caries, independent of the caries diagnostic method used.

Fluoride-releasing capacity and cariostatic effect provided by sealants

This study evaluated the effect of sealants on enamel demineralization, focusing on physical protection of the sealed enamel and fluoride protection of the adjacent unsealed enamel. Occlusal fissures with areas measuring 12 mm2 were delimited in 48 extracted molars, randomly divided into 4 groups (n =12): 1) no sealing; 2) sealing with a resin-modified glass-ionomer (Vitremer, 3M ESPE); 3) sealing with a fluoride-releasing composite sealant (Clinpro Sealant, 3M ESPE); and 4) sealing with a non-fluoridated composite sealant (Concise, 3M ESPE). A 4-mm2 window was outlined on the buccal enamel for analysis of fluoride uptake. Following treatment, groups 2, 3 and 4 were subjected to 5-days of pH-cycling, while group 1 was kept in a moist environment at 37 degrees C. Fluoride uptake was assessed by dental biopsy, and the amount of fluoride released to the cycling solutions was determined by ion analysis. Enamel demineralization around the sealants was evaluated by cross-sectional micro-hardness analysis. Group 2 showed higher levels of fluoride release (P < 0.01) and uptake by enamel (P < 0.05), and lower levels of demineralization (P < 0.05) than groups 3 and 4. Group 3 exhibited reduced demineralization on unsealed enamel and provided fluoride uptake in a distant enamel area, while group 4 did not.

Microleakage assessment of pit and fissure sealant with and without the use of pumice prophylaxis

OBJECTIVES

This study evaluated the effect of pumice prophylaxis on the level of microleakage around and between the sealant and enamel.

MATERIALS AND METHODS

A total of 32 freshly extracted sound upper first premolars, assigned as suitable for sealant application, were chosen and divided randomly into two groups: (1) a test group, without prophylaxis; and (2) a control group, with prophylaxis. Sealant was applied to all teeth using the same conventional technique, with prophylaxis being omitted in the test group. The sealed teeth were thermocycled (120 x 30 s, 5 and 55 degrees C cycles) and then immersed in 2% Basic Fuchsin solution for 72 h. Each tooth was sectioned and examined for dye penetration under a stereomicroscope (x 60 magnification).

RESULTS

No dye penetration was seen in 19 (29.6%) of the teeth in the test group and 36 (56.2%) of the teeth in the control group. Dye had penetrated to the base of the fissure in 31 (48.4%) of the teeth in the test group and 23 (35.9%) of the teeth in the control group. Using a chi-square test for trend, the frequency of microleakage was significantly higher in the test group compared to the controls (P < 0.016).

CONCLUSION

Prophylaxis has a role in improving sealant retention. Removing this step may cause an increase in microleakage.

Pit and fissure sealants for preventing dental decay in the permanent teeth of children and adolescents

BACKGROUND

Fissure sealants used on occlusal tooth surfaces were introduced in the 1960s for protecting pits and fissures from dental caries. Although sealants have demonstrated to be effective in preventing caries, their efficacy may be related to the background caries prevalence in the population.

OBJECTIVES

The primary objective of this review was to evaluate the caries prevention of resin based pit and fissure sealants and glass ionomer cements or sealants in children and adolescents.

SEARCH STRATEGY

We searched the Cochrane Oral Health Group's Trials Register (last update December 2002), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2002), MEDLINE via OVID (1966 to December 2002), EMBASE (1974 to February 2002), SCISEARCH, SIGLE, CAplus, INSPEC, JICST-EPLUS, NTIS, PASCAL (February 2002) and DARE, NHS EED, HTA (March 2002). Reference lists from included articles and review articles were searched for additional relevant articles. All relevant studies in most languages were considered and translated.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of at least 12 months in duration in which sealants were used for preventing caries in children and adolescents under 20 years of age were included. The primary outcome was the increment in the numbers of carious occlusal surfaces of premolars and molars.

DATA COLLECTION AND ANALYSIS

In the first phase, two reviewers independently examined whether a given study was likely to be relevant on the basis of the title, key words and abstract. In the second phase, four of the reviewers independently classified studies to be included in final analyses. Study authors were contacted for additional information. In the split-mouth studies relative risk ratios were calculated for the paired differences of tooth surfaces being carious or not. In studies comparing resin based sealant with no treatment, fixed effect meta-analyses were used to combine the estimates of relative risk ratios. In one parallel group study, the mean DFS data as continuous data, the effect estimate being the difference in mean DFS, was calculated from data of occlusal surfaces of teeth included in the test and control groups.

MAIN RESULTS

Eight trials were included in this review of which seven trials were split-mouth studies and one a parallel group study. Six studies provided data for comparing sealant with no treatment and three studies for comparing glass ionomers with resin based sealants. The overall effectiveness of resin based sealants in preventing dental decay on first molars was high. Based on five split-mouth studies with 5 to 10 year old children there were significant differences in favour of the second-generation resin sealant compared with no treatment with pooled relative risk values of 0.14, 0.24, 0.30, 0.43 at 12, 24, 36 and 48 to 54 months respectively. The reductions in caries therefore ranged from 86% at 12 months to 57% at 48 to 54 months. The 24 month parallel group study comparing second-generation resin sealant with control in 12 to 13 year old children found also significantly more caries in the control group children with DFS = 0.65 (95% CI 0.47 to 0.83). Allocation concealment was classified adequate in three of these six studies. However the information on background levels of caries in the population was insufficient to conduct further analyses to estimate the effectiveness of resin based sealants related to baseline caries prevalence. Only one study provided data for the comparison between glass ionomer sealant and control. Based on this, there is not enough information to say whether ionomer sealants are effective, or not. The results of three studies comparing resin sealants with glass ionomer sealants were conflicting and the meta-analyses were not carried out.

REVIEWERS' CONCLUSIONS

Sealing with resin based sealants is a recommended procedure to prevent caries of the occlusal surfaces of permanent molars. However, we recommend that the caries prevalence level of both individuals and the population should be taken into account. In practice, the benefit of sealing should be considered locally and specified guidelines for clinicians should be used. The methodological quality of published studies concerning pit and fissure sealants was poorer than expected.

A 5-year evaluation of two glass-ionomer cements used as fissure sealants

OBJECTIVE

To evaluate the retention and caries preventive effect of two glass ionomers used as fissure sealants: one resin modified glass ionomer (A) and one conventional glass-ionomer cement (B).

SAMPLES AND METHODS

The permanent first molars of 100 children, 6-8 years of age at the start of the study, were sealed. Material A was applied on one side (right side, upper, and lower) and material B was applied on the contralateral side (left side, upper, and lower) of the mouth. The control group was composed of 108 children who did not receive fissure sealant but received oral health education. After 5 years, 64.0% of the children of the experimental group and 73.0% of the children of the control group were available for reexamination.

RESULTS

Material A was completely lost in 74.2% and material B in 89.0% (Wilcoxon matched pairs test, P < 0.05). Total retention rate was 1.6% for materials A and B. After 5 years, caries increment was 21.5% for the experimental group and 34.2% for the control group (chi2-test, P < 0.05).

CONCLUSION

Sealing pits and fissures with glass-ionomer cements was effective in preventing caries.

Effects of tooth-conditioning agents on bond strength of a resin-modified glass-ionomer sealant to enamel

OBJECTIVES

The purpose of this study was to evaluate the effects of tooth-conditioning agents on bond strength of resin-modified glass-ionomer sealant (Fuji III LC) to bovine enamel as well as on dissolution of calcium ions from the bovine enamel surfaces.

METHODS

The enamel surfaces of bovine lower incisors were treated with 10 and 20% polyacrylic acid, 12% citric acid and 35% phosphoric acid for 20s. Fuji III LC was applied to the etched enamel surfaces, and the shear bond strength of each specimen was measured using an Instron Universal Testing Instrument. The amounts of calcium ions dissolved from the treated enamel surfaces were also measured using a polarized Zeeman atomic absorptiometer.

RESULTS

In specimens pretreated with distilled water, 10% polyacrylic acid, 20% polyacrylic acid, 12% citric acid and 35% phosphoric acid, the mean values of shear bond strength were 5.5, 12.5, 15.2, 15.2 and 15.1MPa, respectively, and the amounts of Ca(2+) dissolved from the enamel surfaces were 5.6, 41.4, 88.5, 131.6 and 588.3 microg/cm(2), respectively.

CONCLUSIONS

The adhesion of a resin-modified glass-ionomer sealant to bovine enamel was significantly improved by the use of tooth-conditioning agents. Especially, treatment of an enamel surface with 20% polyacrylic acid results in good shear both strength and relatively small degree of enamel erosion.

Wear and superficial roughness of glass ionomer cements used as sealants, after simulated toothbrushing

The purpose of this study was to evaluate, in vitro, the properties (wear and roughness) of glass ionomer cements that could influence their indication as pit and fissure sealants. The utilized materials were Fuji Plus, Ketac-Molar and Vitremer (in two different proportions: 1:1 and :1). The resin-based sealant Delton was used as control. By means of an electronic balance (precision of 10-4 g), wear was measured in function of weight loss after simulated toothbrushing. Superficial roughness was determined by means of a surface roughness-measuring apparatus. The results revealed that diluted Vitremer and Fuji Plus were less resistant to toothbrushing abrasion and had the greatest increase in superficial roughness. Although in clinical situations luting or diluted ionomer cements are often utilized as alternatives to resin-based sealants, the resultsof this study revealed that the properties of those cements are worse than those of restorative ionomers, whichpresented results similar to those of the evaluated resin sealant.

An in vitro study on restoring bond strength of a GIC to saliva contaminated enamel under unrinse condition

OBJECTIVES

This study attempted to find a method of restoring the tensile bond strength of glass ionomer cement (GIC) to saliva contaminated enamel under unrinse condition.

METHODS

One hundred and thirty human non-carious permanent teeth were divided into two major groups. Either treatment with air drying, acetone, polyacrylic acid, maleic acid, tartaric acid, Scotchbond primer or no treatment at all was applied to both clean and saliva contaminated enamel surfaces prior to GIC placement. Samples were debonded in tension after 7 days of storage in water using a universal testing machine. Statistical analysis was performed using one-way ANOVA, Tukey's studentized range test and Wilcoxon's rank sums test to determine the significance of the difference of tensile bond strengths within and between the two major groups.

RESULTS

Bond strength of GIC to clean enamel was 2.46+/-0.79 MPa while the bond strength of GIC to wet contaminated enamel was significantly reduced to 1.28+/-0.32 MPa (p<0.01). However, the bond strengths were restored when the contaminated enamel surfaces were air-dried (2.19+/-0.38 MPa) or applied with either maleic acid (2.80+/-0.63 MPa) or Scotchbond primer (2.13+/-0.65 MPa) before placing GIC over the enamels.

CONCLUSIONS

Air drying, or application of maleic acid or Scotchbond primer to the contaminated enamel without rinsing prior to GIC placement can restore the tensile bond strength to a level similar to that of non-contaminated control.

Does ART have a place in preservative dentistry?

The ART technique consists of hand excavating carious tissue and placing a highly viscous glass ionomer cement as a restoration material and as a sealant. Although the results of several studies are promising, the retention rates of these restorations for primary teeth are not impressive. Materials and methods that yield greater success rates are needed to improve long-term caries management outcomes. In principle, ART should yield outcomes similar to those associated with preservative dentistry, including the potential for minimal surgical intervention, conservation of sound tooth structure, avoidance of pain and need for local anesthetic injections, reduced risk for subsequent endodontics and tooth extraction, and increased survival time of the affected teeth. The ideal direct-filling ART material would be biocompatible and tooth colored; "forgiving" in its handling properties; insensitive to moisture or desiccation; hardenable without special equipment; able to form stable bonds to enamel and dentin; able to seal marginal gaps against bacteria; capable of releasing fluoride or remineralization and antibacterial agents when demineralization is most likely; and resistant to chemical attack. The highly viscous glass ionomer materials currently used for ART meet several of this criteria, though they may be deficient in their ability to seal marginal gaps against bacteria and in their sensitivity to desiccation. Furthermore, although they release fluoride over the lifetime of the restoration, this fluoride release alone may not prevent caries progression in all cases. It is necessary for cases of high caries risk to use chlorhexidine in conjunction with fluoride to achieve caries arrest and remineralization of adjacent areas of the affected teeth. Thus, while the ART technique offers some benefits in restoring function and reducing the rate of caries progression, it is unlikely that current materials will be able to arrest caries progression completely in high-risk persons.

How effective is ART in the management of dental caries?

The ART approach involves excavating cavitated dentine caries with hand instruments, then restoring the cavity and sealing any associated fissures and pits with an adhesive restorative material, resulting in a sealant restoration. Until recently, ART has mainly been used under field conditions, and thus the adhesive restorative material used has been glass ionomer which does not require mixing machines and curing lights. Since the inception of ART, a growing number of studies world-wide have taken place. A total of four studies have reported 3-year survival percentages for one-surface ART restorations. The highest 3-year survival percentage in permanent teeth was 88%, which is comparable to the 85% survival of one-surface amalgam restorations placed under the same field conditions after 3 years. The outcomes depend to some extent on the material used, operator experience and presence of caries. The presence of caries as a reason for failure was higher in the early than in the most recent studies. Only one study has reported on the use of ART restorations in the deciduous dentition. It is concluded that: a very large proportion of dentine lesions in the permanent teeth can be treated using the ART approach; the 3-year survival rate of the more recently placed one-surface ART restorations in permanent teeth was higher than that of ART restorations placed in the beginning; the survival of one-surface ART restorations in the permanent dentition with newer glass ionomers is comparable to that of one-surface conventional restorations placed using amalgam in a comparable setting after 3 years; more studies of longer duration are needed to confirm these findings; ART should be considered a caries treatment modality that benefits people; and educational courses need to be organised before the approach is applied in the clinic.

Variability of cytotoxicity and leaching of substances from four light-curing pit and fissure sealants

It was the aim of our study to investigate the composition and cytotoxicity of aqueous extracts of four light-curing pit and fissure sealants. Water extracts were analyzed by gas chromatography/mass spectrometry (GC/MS), and relative quantities of identified compounds were compared by means of an internal caffeine standard [%CF]. Cytotoxic effects due to medium extracts were determined by means of permanent 3T3 fibroblasts. All light-curing pit and fissure sealants segregated different ingredients into water, such as co-monomers (mainly ethylene glycol compounds) and initiating substances (e.g., camphorquinone). Bisphenol-A, however, which is easily detected by GC/MS, was not found in any of the analyzed eluates. The extracts of three sealants inhibited monolayer growth only moderately whereas the eluate of one product inhibited cell proliferation significantly. In the extracts of this sealant high quantities [%CF] of the co-monomer TEGDMA were detected. Our results indicate that light-curing pit and fissure sealants release substances into aqueous media that may induce cytotoxic effects. However, no concerns about potential estrogenic effects of Bisphenol-A are supported by our results.

Retention of titanium tetrafluoride (TiF4), used as fissure sealant on human deciduous molars

When dental hard tissues are exposed to aqueous solutions of TiF4, an acid-resistant glaze forms on tooth surfaces. The aim of the present study was to examine the long-term retention of the glaze on TiF4-treated deciduous molars. The occlusal surfaces of four deciduous molars in each of seven children were treated with 4% TiF4 for 1 min. The sealed teeth were extracted after 1, 3, 6, or 12 months and examined with scanning electron microscopy. An extensive surface layer was present on all deciduous molars after 1 month. After 3 months the glaze appeared to be worn out on the cusp tips and in some areas on the cusp inclines. At 6 months the glaze was observed as small areas distributed over the cusp inclines with total coverage of the pits and fissures. After 1 year the presence of the glaze was limited to pits and fissures. Clinically, all fissures were caries-free by visual inspection at the end of the experimental period. The results indicate that the glaze formed after topical TiF4 application may be an effective way of sealing pits and fissures under clinical conditions.

A study of component release from resin pit and fissure sealants in vitro

OBJECTIVE

A recent study reported that an estrogenic chemical, bisphenol-A, was released from a fissure sealant. The aim of this study was to identify and quantify the major (or detectable) components released from any of seven commercially-available, light-cured pit and fissure sealants in vitro.

METHODS

The fissure systems of ten extracted, third molar teeth were filled with sealant, light-activated and immersed in separate containers of distilled water. Separate, cylindrical stainless steel molds were filled with sealant which was then light-activated and immersed. Each mold or tooth with sealant was moved to a new container of water at defined times and each remaining water sample (eluate) then analyzed by high performance liquid chromatography (HPLC).

RESULTS

Triethylene glycol dimethacrylate (TEGDMA) was present in all eluates from each of the sealants tested. 2,2-bis[4'-(2'-hydroxy-3'-methacryloyloxy)phenyl]propane (BisGMA) was detected at much lower levels (about one thousand-fold less) in eluates from one sealant only. Bisphenol-A was not detected in any eluates. The rates of TEGDMA and BisGMA release were highest on first immersion and decreased thereafter. The total amount of TEGDMA released was on the order of 0.25 mg per tooth. Most release occurred during the first day.

SIGNIFICANCE

Because bisphenol-A release could not be detected from any of the seven sealants tested, these results call into question earlier concerns expressed about possible adverse effects of bisphenol-A released from resin sealants.

Fissure sealing with a light-cured resin-reinforced glass-ionomer cement (Vitrebond) compared with a resin sealant

The aims of the present study were to evaluate the retention and caries-preventive effect of a single application of a light-cured resin-reinforced glass-ionomer cement (Vitrebond) in pits and fissures of newly erupted permanent first and second molars, when compared with a single application of a resin-based sealant (Concise White Sealant) during a 3-year period. The study group comprised 73 pairs of contralateral newly erupted permanent first and second molars (136 fissure sites) in 53 children (29 girls, 24 boys). A split-mouth experimental design was used in which the two sealants were randomly allocated to one of the teeth within each pair. Acid etching was not used before application of the glass-ionomer cement. The sealed teeth were checked for retention and caries after 1, 6, 12, 24 and 36 months. The resin-based sealant was almost totally retained after 3 years (97%) and there was no caries in these teeth. The glass-ionomer cement was increasingly lost and could be observed in only 9% of the sealed sites after 3 years. Carious lesions developed in 10 (7.4%) sites (nine teeth, seven children). It was concluded that the resin-based sealant is superior to the glass-ionomer cement in preventing caries, and that the superior retention of the resin probably is an important factor for this.

Using a resin-modified glass ionomer as an occlusal sealant: a one-year clinical study

The authors compared the retention and clinical performance of a resin-modified glass ionomer, or RMGI, restorative and a light-cured resin sealant. The first permanent molars on one side of the dental arch in 50 children were sealed with an RMGI, and the same teeth on the other side were sealed with a resin sealant. At baseline, six months after placement and one year after placement, examiners documented sealant retention, secondary caries, marginal discrepancy and marginal staining. In general, the RMGI appeared to wear markedly. At one year, the retention of the RMGI was significantly less than the resin, but the RMGI had significantly fewer marginal discrepancies. There were no significant differences in caries development or marginal discoloration.

Glass ionomer as fissure sealant--a critical review

This paper presents a review of the literature on glass ionomer cements used as fissure sealants. An objective assessment of the presently available scientific literature on the use of glass ionomer materials as pit and fissure sealants is not encouraging in terms of retention, but appears somewhat more positive for caries prevention. At the time of this writing, the published literature indicates that retention for resin-based sealants is better than for glass ionomer sealants, but differences in caries prevention remain equivocal. Future research should concentrate on assessing the effects of fluoride-releasing, resin-modified, glass ionomer materials.