Fluoride-releasing Sealant Research Articles

Effect of Surface Pre-Reacted Glass Ionomer Containing Dental Sealant on the Inhibition of Enamel Demineralization.

The effect of a surface pre-reacted glass ionomer (S-PRG)-containing sealant on the demineralization inhibition and remineralization of intact enamel adjacent to the sealant material was investigated. BeautiSealant (BTS, S-PRG sealant, Shofu), Teeth Mate F-12.0 (TMF, fluoride-releasing sealant, Kuraray Noritake Dental), and an experimental silica-filler sealant were investigated. After pH cycling for 10 days, the enamel surface adjacent to the sealant material was observed using confocal laser microscopy and scanning electron microscopy. The polymerized sealant disks were immersed in a demineralized solution (pH: 4.3) to measure pH change. The enamel specimens with polymerized sealant disks were additionally immersed in demineralized solution, followed by energy-dispersive X-ray spectroscopy. The demineralized area of BTS was significantly smaller than that of TMF and SS (p < 0.05). The surfaces adjacent to the sealant of TMF and SS were demineralized, while the surface of BTS was comparatively intact. An increase in pH values were observed in the BTS and TMF groups. Enamel surfaces presented an inhibition of demineralization for BTS and TMF, but not for SS. Fluoride uptake from the polymerized sealant was greater for BTS than for TMF. The S-PRG-containing sealant showed a buffering ability, demineralization inhibition, promotion of remineralization, and it can be advised for clinical applications.

Sealants for preventing dental caries in primary teeth.

Sealants for preventing dental caries in primary teeth.

Effect of Aging on the Microhardness of Different Resin-based Fluoride-releasing Fissure Sealants: An In Vitro Study

The aim of the present study was to evaluate the effect of aging on the microhardness score [Vickers hardness number (VHN)] of different resin-based fluoride-releasing sealants compared to non-fluoride resin-based sealants. A total of 48 extracted sound molars that were sectioned mesiodistally were used. In the current study, four types of sealants were compared: Group A, a resin-based non-fluoride-releasing pit and fissure sealant (Eco-S sealant) served as a control. Groups B, C, and D received resin-based fluoride-releasing pit and fissure sealants Helioseal F, Fissurit F, and Embrace™ WetBond, respectively. Subsequently, each group was further divided into immediate and aged subgroups. The samples had been evaluated regarding their microhardness using a pyramidal diamond indenter of a Vickers hardness test at two-time intervals: Immediately and after the aging process through thermocycling. There were no statistically significant differences between mean VHN and material types (p = 0.72). Aging appeared to significantly increase the mean VHN (p = 0.001). The interaction model between material type and time factor showed that the effect of aging differs by the material type, where the VHN of the Embrace™ group increased significantly after aging from 24.33 ± 5.60 to 31.70 ± 3.59 (p = 0.001). While there were no significant differences in the microhardness of commonly used fluoride-releasing fissure sealants, time appears to significantly increase the mean microhardness score (VHN), especially in the Embrace™ group. Embrace™ WetBond fissure sealant showed a significant improvement in the mean microhardness score (VHN) with time. However, clinical studies with long-term follow-up are needed to confirm our results.

Efficacy of sealants and bonding materials during fixed orthodontic treatment to prevent enamel demineralization: a systematic review and meta-analysis

To analyse clinical studies investigating coating agents such as sealants and other bonding materials to prevent the initiation or inhibit the progress of white spot lesions (WSL) during orthodontic treatment with fixed appliances. Electronic databases (Pubmed, CENTRAL, EMBASE) were screened for studies. No language restrictions were applied. Study selection, data extraction and quality assessment were done in duplicate. Primary outcome included assessment of WSL with visual-tactile assessment and/or laser fluorescence measurements. Twenty-four studies with 1117 patients (age: 11–40 years) and 12,809 teeth were included. Overall, 34 different sealants or bonding materials were analysed. Fourteen studies analysed fluoride and 14 studies non-fluoride releasing materials. Meta-analysis for visual tactile assessment revealed that sealants significantly decreased the initiation of WSL compared to untreated control (RR [95%CI] = 0.70 [0.53; 0.93]; very low level of evidence). Materials releasing fluoride did not decrease initiation of WSL compared to those with no fluoride release (RR [95%CI] = 0.84 [0.70; 1.01]; very low level of evidence). For laser fluorescence measurements no meta-analysis could be performed. The use of sealants seems to be effective in preventing the initiation of post-orthodontic WSL. Furthermore, there is no evidence supporting that fluoride-releasing sealants or bonding materials are more effective than those without fluoride release. No gold standard prevention strategy to prevent WSL during treatment with fixed orthodontic appliances has been established yet. However, based on only a limited number of studies the use of sealants seems to be effective in preventing the initiation of post-orthodontic WSL.

Analysis of follow-up changes in incidence of oral diseases in Novosibirsk schoolchildren during the preventive treatment program

Relevance. The Russian Federation state program „Healthcare system development”, approved on April 15, 2014, relies on the introduction of the specialist „Dental Hygienist” in the system of school dentistry service as the main executor of the preventive treatment program. Government resolution #1640 as of 26.12.2017, which is to be realized during 2018-2025, included the agency project „“Primary prevention of oral diseases among the population of the Russian Federation”. The realization of the oral disease prevention project (professional cleaning, fluoride local application, permanent molar fissure sealing) is a basic program that includes necessary steps to reduce oral disease incidence rate and caries increase in schoolchildren. Administration of oral care products (fluoride varnish, sealants) immediately after tooth eruption, i.e., during formation and mineralization of the hard dental tissues, is more relevant, than the use of these products after the mineralization is complete. Aim – to assess the effectiveness of oral disease preventive measures by the analysis of the follow-up changes in the dental status of schoolchildren.Materials and methods. 115 first-grade schoolchildren of two Novosibirsk general schools participated in the study. The schoolchildren were evenly divided into 2 groups: prevention and comparison. The parents and children of both groups were trained how to take care of the oral cavity at home. The children in both groups were examined, oral hygiene indices were determined and the teeth were treated. The preventive treatment in the first groups was administered with the following materials: fluoride varnish with innovative ingredient, tricalcium phosphate, and low fill fluoride-releasing light-cured sealant. The materials are certified and approved for use in children in the Russian Federation. The individual preventive treatment was not performed in the second group. The effectiveness of the preventive treatment was assessed by the analysis of follow-up changes in the dental status of the schoolchildren.Results. The school preventive treatment program demonstrated a significant reduction of caries increase rate – up to 31.79% in the prevention group, which forms the basis for performance optimization of the school dental office where the priority belongs to a dental hygienist.Conclusions. The results of the preventive treatment program with the participation of a pediatric dentist and a dental hygienist held in three Novosibirsk schools confirmed its high medical effectiveness.

The antibacterial effect and physical performance of pit and fissure sealants based on an antibacterial core–shell nanocomposite

The application of pit and fissure sealants is a well-established method to prevent and treat early childhood caries. Resin-based sealants with antibacterial properties provide additional benefits for caries prevention in a cariogenic oral environment. The objective of this study was to evaluate the effect of an antibacterial core–shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) on the properties of a resin-based pit and fissure sealant. A commercialized pit and fissure sealant without fluoride, Concise (3M, ESPE, USA), was used as the parent material and negative control. Experimental antibacterial sealants were formulated by the addition of AgBr/BHPVP nanoparticles at mass fractions of 0.5, 1.0, and 1.5 wt% to the parent material. A fluoride-releasing sealant, Clinpro (3M, ESPE), was used as the positive control. Bacterial colony-forming unit (CFU) counts, metabolic activity tests, field emission–scanning electron microscopy (FE–SEM), and confocal laser scanning microscopy (CLSM) observations were used to evaluate the antibacterial properties of AgBr/BHPVP-modified sealants against Streptococcus mutans before and after five months of aging. The Vickers microhardness, degree of conversion, and microleakage level of the sealants were also investigated. According to the results of CFU counts and metabolic tests, sealants containing AgBr/BHPVP showed better contact-killing bactericidal activity against S. mutans than the two commercial sealants, irrespective of aging conditions (both P < 0.05). The AgBr/BHPVP-modified sealants also showed a significant inhibitory effect on the planktonic S. mutans around the cured sealant surfaces. In addition, the Vickers microhardness, degree of conversion, and microleakage level of the parent material were not damaged by modification with AgBr/BHPVP (P > 0.05). AgBr/BHPVP-modified pit and fissure sealant with a dual bactericidal mechanism is a promising option for the prevention of pit and fissure caries.

Sealed primary molars are less likely to develop caries

BackgroundThe authors examined the association between light-polymerized resin-based fluoride-releasing sealants and the development of pit-and-fissure caries on primary molars. MethodsIn this 3-year retrospective study, the authors reviewed the dental records of 297 children (1,352 teeth) younger than 6 years who were at high caries risk. Sealant placement or nonplacement on primary molars in the outpatient clinic and operating room setting was recorded, and random-effects logistic regression analysis accounting for the effect of data clustering was performed to measure caries incidence over time. ResultsThe odds of developing pit-and-fissure carious lesions on sealed primary molars were 0.055 times (95% confidence interval [CI], 0.011 to 0.285; P = .001) and 0.013 times (95% CI, 0.001 to 0.159; P = .001) the odds of that on nonsealed primary molars in the outpatient clinic and in the operating room, respectively. In molars that became carious, those sealed were associated with longer time to caries development in both the outpatient clinic (2.69 years, 95% CI, 2.08 to 3.29) and operating room (1.97 years, 95% CI, 1.45 to 2.48). ConclusionsSealed primary molars were less likely to develop pit-and-fissure caries when placed in both the clinic and operating room settings. Practical ImplicationsDental sealants on primary molars should be considered for children at high caries risk.

Effectiveness of caries-preventing agents on initial carious lesions within the scope of orthodontic therapy

ObjectiveTo evaluate the effectiveness of three different caries-preventing agents on artificial caries in a Streptococcus mutans-based caries model.MethodsSixty-five caries-free human molar enamel blocks were treated with a demineralization solution and a remineralization solution. The specimens were assigned to the following groups according to the caries-protective product applied: group A, chlorhexidine varnish; group B, fluoride-releasing chemically cured sealant; group C, fluoride-releasing lightcured sealant; group D, positive control (specimens that were subjected to de- and remineralization cycles without treatment with any caries-protective agents); and group E, negative control (specimens that were not subjected to de- and remineralization cycles). Samples in groups A–D were stored in demineralization solution with S. mutans and thereafter in artificial saliva. This procedure was performed for 30 days. Average fluorescence loss (ΔF) and surface size of the lesions were measured using quantitative light-induced fluorescence at baseline and on the 7th, 14th, and 30th days.ResultsAfter 30 days, group A demonstrated a significant increase in ΔF and the surface size of the lesions, no significant difference in comparison with the positive control group, and a significant difference in comparison with the negative control group. Group B showed no significant changes in both parameters at any of the measurement points. While group C showed increased ΔF after 14 days, no significant fluorescence change was observed after 30 days.ConclusionsBoth fluoride-releasing sealants (chemically or light-cured) show anti-cariogenic effects, but the use of chlorhexidine varnish for the purpose of caries protection needs to be reconsidered.

Effect of a fluoride-releasing fissure sealant and a conventional fissure sealant on inhibition of primary carious lesions with or without exposure to fluoride-containing toothpaste.

Background. Fluoride-releasing capacity has been added to fissure sealants to benefit from the positive anticariogenic effects of both sealants and fluoride. This comparative research investigated the inhibitory effects of conventional and fluoridereleasing fissure sealants on initial lesions with or without exposure to fluoride toothpaste. Methods. Cavities were prepared on buccal surfaces of 24 premolar teeth which were randomly divided into three groups. In the cavities of the first group, a fluoride-releasing fissure sealant and in the second group, a conventional fissure sealant were placed; the third group was left intact. Incipient lesions were produced around the cavities. Each group was divided into two subgroups, which were exposed to fluoride-containing toothpaste or artificial saliva. Lesion depths were measured under a polarized light microscope before and after treatment. Changes in lesion depths in the samples were analyzed by SPSS 17. Results. Initial and final caries depths were significantly lower in the fluoride-releasing fissure sealant group compared to the other groups (P<0.001). The average depths of carious lesions were lower in subgroups exposed to fluoride-containing toothpaste than the subgroups exposed to artificial saliva and the difference was significant in the conventional sealant group and the group without sealant (P<0.001); however, the difference between the toothpaste-exposed and saliva-exposed subgroups was not significant in the fluoride-releasing fissure sealant group (P=0.721). Conclusion. Incorporation of fluoride into the fissure sealants can be effective in the inhibition of dental caries. It seems that fluoride, released from fluoride-releasing sealants, overwhelms the remineralizing capacity of fluoride released from the toothpaste on the same tooth.

Retention of moisture-tolerant fluoride-releasing sealant and amorphous calcium phosphate-containing sealant in 6-9-year-old children: A randomized controlled trial.

Pits and fissures of teeth have been recognized as the most susceptible areas for initiation of caries. The ability of the resin sealant to thoroughly fill pits, fissures, and/or morphological defects and remain completely intact and bonded to enamel surface is the primary basis for its caries prevention. The present study evaluated and compared the retention rates and development of caries in permanent molars of children sealed with amorphous calcium phosphate-containing (Aegis™) and moisture-tolerant fluoride-releasing (Embrace WetBond™) sealant over a period of 1 year. This was a double-blind, split-mouth, randomized controlled trial among children aged 6-9 years. Sixty-eight permanent mandibular first molars in 34 children were randomly assigned to be sealed with Aegis™ or Embrace Wetbond™ sealant. The follow-up examinations were conducted at 3, 6, and 12 months for evaluating the retention and development of caries. SPSS version 16.0 was used for the analysis. Within-group comparison of retention and development of caries at 3, 6, and 12 months was evaluated using the Friedman's test. The final sample was 32 children with 64 teeth. At 12 months, 23 of 32 (72%) sealants were completely retained in Aegis™, whereas 21 of 32 (65.6%) were retained in Embrace Wetbond™ group. There was no significant difference in the retention rates of Aegis™ and Embrace Wetbond™ sealants at 12 months (P > 0.05). Aegis™ was superior to Embrace Wetbond™ sealant as Aegis™ exhibited higher retention and lower caries scores.

Dental Sealants Part 3: Which material? Efficiency and effectiveness.

Determining the best choice between the different sealant materials might be complicated. The products that dentists can choose have different properties, such as caries' preventive effect, fluoride release and retention rate. According to the literature, fissure sealant materials fall into two main categories: resin-based sealants and glass ionomer sealants. Even if the "fluoride-releasing resin sealants" are better than "glass ionomer", with regards to retention of the material, the literature shows that their effectiveness in preventing fissure caries in permanent molars does not differ significantly over 24 months.

Assessment of the degree of conversion in light-curing orthodontic resins with various viscosities

The aim of this study was to determine the degree of conversion (DC) for five orthodontic resins with different viscosities, to examine a probable relationship between the viscosity factor and the degree of conversion of the materials. Five commercially-available light-cured orthodontic bonding resins were used in this study: two medium viscosity resins [transbond XT (TR); opal bond MV (OB)]; two low viscosity resins [vertise flow (VF); opal bond flow (OF)]; and a fluoride-releasing sealant [opal seal (OS)]. The specimens were made and polymerized for 20 s. Fourier Transformed Infrared spectroscopy (FTIR) was used to assess the DC of carbon-carbondouble bonds from all samples. The DC was significantly different among the materials: (TR, 24.6 ± 0.04 %; OB, 39 ± 0.02 %; VF, 44.3 ± 0.01 %; OS, 52.5 ± 0.01 %; OF, 53 ± 0.04 %; p < 0.05) and the lowest viscosity materials had the highest DC values. The resins studied have different DC values, which can be explained by the unique composition of each brand of resin. There is a relationship between the viscosity of a material and its degree of conversion, which is shown in this study by the two low-viscosity orthodontic resins that had a higher DC.

In-vivo durability of a fluoride-releasing sealant (OpalSeal) for protection against white-spot lesion formation in orthodontic patients.

BackgroundSealant application during fixed appliances orthodontic treatment for enamel protection is common, however, reliable data on its durability in vivo are rare.ObjectiveThis study aims at assessing the durability of a sealant (OpalSeal, Ultradent) for protection against white-spot lesion formation in orthodontic patients over 26 weeks in vivo, taking into account the provision or absence of an adequate oral hygiene. We tested the null hypothesis of (1) no significant abatement of the sealant after 26 weeks in fixed orthodontic treatment compared to baseline, and (2) no significant influence of the factor of brushing and oral hygiene (as screened by approximal plaque index, API) on the abatement of the sealant.MethodsIntegrity and abatement of OpalSeal applicated directly following bracketing was assessed in thirty-six consecutive patients (nteeth = 796) undergoing orthodontic treatment with fixed appliances (male/female12/24; mean age/SD 14.4/1.33 Y). Assessment of the fluorescing sealant preservation was by a black-light lamp, using a classification that was concepted in analogy to the ARI index: (3, sealant completely preserved; 2= > 50% preserved; 1 = <50%; 0 = no sealant observable) immediately following application (Baseline, T0), after 2 (T1), 8 (T2), 14 (T3), 20 (T4) and 26 weeks (T5). API was assessed at T0 and T1. Statistical analysis was by non-parametric repeated measures ANOVA (α = 5%, power >80%).ResultsAt baseline, 43.4% of teeth had a positive API. Oral hygiene deteriorated after bracketing (T1, 53%) significantly. Null hypothesis (1) was rejected, while (2) was accepted: Mean values of both the well brushed and non-brushed anterior teeth undercut the score “1” at T3 (week 14). Despite a slightly better preservation of the sealer before and after T3 in not-sufficiently brushed (API-positive) teeth, this finding was statistically not significant.ConclusionOne single application of OpalSeal is unlikely to last throughout the entire fixed appliance treatment stage. On average, re-application of the sealant can be expected to be necessary after 3.5 months (week 14) in treatment.

Fluoride releasing sealants may possess minimal cariostatic effect on adjacent surfaces.

Randomised controlled trial. Children with at least two sound permanent first molars and the presence of at least one sound distal surface of adjacent second primary molar were eligible. Children were randomised into three groups. In group one first permanent molars were sealed with a high-viscosity glass ionomer cement (GIC group; n = 926), group two received a resin-based fluoride containing sealant (RBF group; n = 923) and group three a resin-based sealant without fluoride (RB group; n = 927). Two examiners blind to group allocation conducted examinations at 30 months. Sealant retention and caries at D1-D3 levels was assessed. Bitewing radiographs were taken. Caries prevalence and incidence rate ratios were calculated. Two thousand seven hundred and seventy-six children were enrolled; the number of dropouts were similar in each group (GIC group; n = 75), (RBF group; n = 67), (RB group; n = 77). The prevalence of affected surfaces was significantly lower in the GIC (p = .03) and FRB groups (p = .04). Fewer new caries developed on the distal surfaces of the second primary molars in the GIC group than in the other two groups. Incidence rate ratios (IRRs) were: 0.70 (95% CI: 0.50, 0.68; p < .01) for GIC vs. RB; 0.89 (95% CI: 0.89, 1.28; p = .10) for GIC vs. FRB and 0.79 (95% CI: 0.53, 1.04; p = .005) for FRB vs RB. Partial sealant loss was higher in the GIC group (76 molars; 2.95%), compared with FRB (52 molars; 1.41%), RB group (50 molars;1.35%). Fluoride-releasing sealants (high-viscosity GIC and fluoride RB) were demonstrated to provide protection against caries on the distal surface of second primary molars. This preventive strategy might contribute to maintaining the integrity of the mesial surfaces of the first permanent molars.

Assessment and comparison of microleakage of a fluoride-releasing sealant after acid etching and Er: YAG laser treatment - An in vitro study

Aim:The aim of the present study was to estimate and compare the microleakage of a pit and fissure sealant after etching and Er:YAG laser treatment.Materials and Methods:Twenty non-carious premolars extracted for orthodontic reasons were equally divided into two groups. Samples in Group- I were treated with 37% phosphoric acid. Samples in Group II were irradiated with Er: YAG laser at 400 mJ at 4 Hz. Sealant was placed and light cured. Then, the samples were subjected to thermocycling. The samples were then immersed in 1% methylene blue. The samples were sectioned and examined under stereomicroscope at ×10 magnification.Results:Acid etched samples showed significantly less microleakage when compared to laser etching and it was statistically significant (P<0.01).

Effect of tooth bleaching on shear bond strength of a fluoride-releasing sealant

To evaluate the effect of an in-office plus at-home bleaching protocol on shear bond strength of orthodontic buttons when using a fluoride-releasing sealant. Extracted human molars (160) were randomly divided into bleached (n = 80) and unbleached groups (n = 80). The bleached group was treated with 45% carbamide peroxide for 30 minutes, followed by five applications of 20% carbamide peroxide at 24-hour intervals. After 2 weeks, lingual buttons were bonded on the teeth in both groups using either Transbond XT primer or Pro Seal sealant. The teeth were then stored in artificial saliva and subjected to shear testing at 24 hours and 3 months using a Zwick Universal Test Machine. Comparisons of mean shear bond strength values were made with the analysis of variance test. The Fisher's exact test was used to evaluate the adhesive remnant index scores. The analysis of variance of the 24-hour results indicated a significant difference between the four subgroups (P < .0011). Further simple t-tests indicated that the differences were significant only between bleached and unbleached subgroups (P < .0011). The 3-month results showed the mean shear bond strengths of the unbleached group using Pro Seal sealant was significantly lower than that of the other, though still greater than clinically minimal suggested bond strengths. Interestingly, 15% of the bleached teeth exhibited enamel fracture at the 3-month testing. Both Pro Seal sealant and Transbond XT primer demonstrated reliable shear bond strength values on both bleached and unbleached teeth over time.

Efficacy of a filled-resin sealant in preventing decalcification during orthodontic treatment

Enamel decalcification during orthodontic treatment is a persistent problem. Resin-based sealants have been developed to protect enamel from decalcification. The purpose of this in-vivo study was to compare the effect of a fluoride-releasing filled enamel sealant with that of an unfilled nonfluoride control. A total of 177 teeth in 18 patients were evaluated over a period of 12 to 18 months. A split-mouth design was used; half the teeth were treated with the fluoride-releasing sealant (Pro Seal, Reliance Orthodontic Products, Itasca, Ill), and the contralateral teeth received the control (Transbond MIP, 3M Unitek, Monrovia, Calif). The teeth were photographed before (T1) and after (T2) treatment. A panel of 12 orthodontic faculty and residents evaluated the photographs for decalcification on a graded scale. Sixty-nine percent of the teeth treated with Pro Seal showed progressive decalcification from T1 to T2 vs 72% of those treated with Transbond MIP. In the comparison of the contralateral paired teeth, there was a small average net disadvantage of -0.06 of a tooth per patient (95% CI, -0.97 to 0.85) for Pro Seal compared with Transbond MIP. That difference of 0.06 of a tooth is neither statistically significant (P = 0.90) nor clinically important. The 2 products tested were equivalent in their inhibition of decalcification during orthodontic treatment. The additional time and expense of using the fluoride-releasing sealant to prevent decalcification does not appear to be justified.

Transition of Fluoride into Tooth Substance from Sustained Fluoride-Releasing Sealant - In vitro Evaluation -

How transition of fluorine from orally applied sealant into dental matrix occurs and inhibits caries remains unknown. In the current study, we investigated mechanism of caries protection evaluating movement of fluoride ions from sustained-releasing fluoride sealant by EPMA from a crystallographic point and also from inorganic chemical view. Furthermore, we also evaluated differences of 2 kinds of sealant as a fluoride source, which have different releasing mechanism. Our results demonstrated that fluoride ion released from sealant abundantly accumulated in porous structure of tooth. From this result, it was considered that fluoride ion contributed to caries inhibition by infiltrating into porous structure appeared due to decalcification and enhancing pH environment. This result suggests thinking morphological viewpoint upon efficiency of fluorine in clinical dentistry for caries. When 2 different sealant materials were compared, GI-based sealant significantly released more fluoride ion than resin-based fluorine. Moreover GI-based sealant fluoride ion infiltrated significantly much more into decalcified area than resin-based fluorine. Thus in clinical dentistry, selection of GI-based fluoride ion at early periods and then alternation to long-term keeping resin-based fluorine should be considered to treat caries in a better way.

Effects of sealant and self-etching primer on enamel decalcification. Part I: An in-vitro study

The objective of this study was to compare the resistance to enamel demineralization between self-etching primer (SEP) and conventional sealant in vitro. A total of 120 molar sections were randomly assigned to 3 groups: SEP (Transbond Plus, 3M Unitek, Monrovia, Calif), sealant (Light Bond fluoride-releasing sealant, Reliance Orthodontic Products, Itasca, Ill), or control (no enamel treatment). SEP or sealant was applied following the manufacturer's recommendations. The tooth samples were exposed to rotary brushing for 2 minutes. A 2 x 2-mm window of sound enamel was created by using nail varnish. After 48 or 72 hours of acidic challenge with Ten Cate solution (pH 4.46), the samples were sectioned down to a thickness of 200 microm and stained with rhodomine B dye to evaluate lesions, lesion depths, area of lesions, and total fluorescence by using confocal microscopy. Statistical analyses were performed with 1-way analysis of variance (ANOVA) and Tukey-Kramer tests. The incidence of lesion was 50% in the sealant group and 100% in both the SEP and the control group. The lesion in the sealant group was present only when the sealant integrity was broken. Lesion depth (149.9 +/- 20.5 microm), area (636 +/- 90 x 10(2) microm(2)), and total fluorescence (252 +/- 83 x 10(4)) in the SEP group were similar to those in the controls. Lesion depth (107.6 +/- 45 microm), area (441 +/- 212 x 10(2) microm(2)), and fluorescence (160 +/- 103 x 10(4)) in the sealant group were significantly less than in the SEP and control groups (P <0.05). These results suggest that neither sealant completely protects the teeth against enamel decalcification. The application of sealant provided protection in 50% of the samples, whereas the SEP provided no resistance to enamel demineralization. Protection from acid demineralization depends on the integrity of the sealant.

Potential inhibition of demineralization in vitro by fluoride-releasing sealants

The incorporation of fluoride into sealants has been viewed as a viable way to prevent pit-and-fissure caries by potential inhibition of demineralization through the release of fluoride to enamel. The authors conducted a study to examine the effect of a recently introduced fluoride-releasing sealant (ProSeal, Reliance Orthodontic Products, Itasca, Ill.) on enamel demineralization in an in vitro artificial caries system. The authors randomly assigned 45 extracted human third molars to three treatment groups receiving either conventional sealant without fluoride (Group 1), fluoride-releasing sealant (Group 2) or glass ionomer sealant with high fluoride release (Group 3). They placed cavity preparations on the buccal surfaces of the molars and filled them with the assigned material. They placed acid-resistant varnish on the specimens' enamel surfaces to within 1 millimeter of the sealant, leaving a 1-mm rim of sound enamel available for in vitro enamel caries formation. They thermocycled the teeth (500 cycles) in artificial saliva. They subjected the teeth to an in vitro artificial caries challenge for six weeks to produce caries-like lesions in enamel adjacent to the sealant materials. The authors took longitudinal sections from each tooth, immersed them in water and examined them via polarized light microscopy to determine wall lesion frequencies. The mean (+/- standard deviation) lesion depths were 232 +/- 17 micrometers for Group 1, 144 +/- 21 mum for Group 2 and 128 +/- 15 mum for Group 3. The wall lesion frequency was 12 percent for Group 1 and 7 percent for both Groups 2 and 3. There was a significant difference (P < .05) among the fluoride-releasing materials versus the nonfluoride-releasing material. This study indicates that the new fluoride-releasing sealant substantially reduces the amount of enamel demineralization adjacent to the material. ProSeal provided increased demineralization inhibition compared with a conventional sealant containing no fluoride, but less than that shown by a glass ionomer sealant. ProSeal's physical properties and cariostatic effects may allow for applications beyond traditional sealant use.