Glass Ionomer Fissure Sealants Research Articles

Ectodermal Dysplasia: A Case Report

Ectodermal Dysplasia (ED) is a rare genetic disorder characterized by the aberrant development of ectodermal structures, presenting complex dental, dermatological, and psychological challenges. This case report focuses on a 7-year-old male with ED, delving into his prenatal, natal, and postnatal history, medical and dental records, clinical examination findings, and the subsequent treatment plan. The patient exhibited classical ED features, including missing teeth, dry and fragile skin, prominent lips, cranial abnormalities, reduced facial height, and an enlarged tongue. A multidisciplinary team approach was pivotal in addressing the intricate dental complications associated with ED. Preventive measures such as meticulous oral hygiene, periodic high-fluoride applications, and resin-modified glass ionomer fissure sealants were administered. Prosthodontic interventions were designed to restore function and aesthetics, including upper partial denture and lower overdenture. This case underscores the significance of early and comprehensive dental intervention in ED patients, emphasizing the vital roles played by pediatrics, orthodontics, prosthodontics, surgery, and periodontics in achieving favorable outcomes. Furthermore, it highlights the psychosocial challenges faced by ED individuals, emphasizing the need for holistic care and support.

Comparative evaluation of retention and cariostatic effect of glass ionomer, hydrophobic & hydrophilic resin-based sealants: a systematic review and meta-analysis.

To compare the effectiveness of hydrophilic resin-based versus hydrophobic resin-based and glass-ionomer pit and fissure sealants. The review was registered with Joanna Briggs Institute and followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, Google Scholar, Virtual Health Library, and Cochrane Central Register of Controlled Trials were searched from 2009-2019 using appropriate keywords. We included randomized controlled trials and randomized split-mouth trials conducted among 6-13-year-old children. The quality of included trials was assessed using modified Jadad criteria and risk of bias using guidelines specified by Cochrane. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) guidelines were used to assess the overall quality of studies. We used the random-effects model for meta-analysis. Relative risk (RR) and confidence intervals (CI) were calculated & heterogeneity was tested using I² statistic. Six randomized clinical trials and five split-mouth trials met the inclusion criteria. The outlier augmenting the heterogeneity was omitted. Based on very-low to low-quality evidence, loss of hydrophilic resin-based sealants was less likely as compared to glass-ionomer fissure sealants (4 trials at 6 months; RR = 0.59; CI = 0.40-0.86), while it was similar or slightly lower than hydrophobic resin-based sealants (6 trials at 6 months; RR = 0.96; CI = 0.89-1.03); (6 trials at 12 months; RR = 0.79; CI = 0.70-0.89); (2 trials at 18 months; RR = 0.77; CI = 0.48-0.25). This study revealed that retention of hydrophilic resin-based sealants is better than glass ionomer sealants but similar to hydrophobic resin-based sealants. However, higher-quality evidence is necessary to underpin the outcomes.

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

Objective: We 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: Based on this study, we conclude that ZRGIC, a highly viscous fluoride-releasing cement, effectively seals fissures by interfering with food lodgment and protecting teeth from caries. We also conclude from this research that although the contaminated surfaces are not fully effective in penetrating and adapting the GIC to the tooth surface, they are still adequate for the brief period that will delay the carious process. 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.

An In-Vitro Analysis of Microleakage of Self-Adhesive Fissure Sealant vs. Conventional and GIC Fissure Sealants.

Background: The microleakage of a self-adhesive composite, a glass ionomer fissure sealant and a conventional resin-based fissure sealant were compared. Materials and methods: Fifty intact human molars with well-delineated pits and fissures were used and divided into 5 groups (n = 10). Group 1 specimens were etched (37% phosphoric acid) and sealed with conventional resin-based sealant (Helioseal F, Ivoclar Vivadent). Both Group 2 and 3 specimens were sealed with self-adhesive composite (Constic, DMG), but in Group 3, specimens were also etched (37% phosphoric acid). In Groups 4 and 5, specimens were sealed with a GIC sealant (Equia Fill, GC Company), but Group 5 was also exposed to thermo-light curing (TLC) with a LED polymerization unit (60 s). Subsequently, specimens were thermocycled (1800 cycles, dwelling time of 10 s), immersed in 50% silver nitrate solution (45 min), placed in a photo-developing solution (Kodak) under a lamp (120 W, 6 h), and cut into 3–4 slices. Marginal leakage (dye penetration depth) was evaluated under a light microscope and the worst score of each specimen was recorded (0–3). Results: Constic showed the lowest microleakage (Constic: 80% scored 0 or 1), followed by Helioseal (30% scored 0 or 1) (p = 0.037). Microleakage in groups sealed with Constic (with and without etching) were not different (p = 0.473). The quality of seal deteriorated after etching when Constic was used. However, TLC improved the seal when GIC sealant was used (p = 0.016) and also in comparison to Helioseal (p = 0.004). The TLC GIC sealant (Equia Fill, 90% scored 0 or 1) performed well, similar to self-adhesive composite (Constic, 80% scored 0 or 1) (p = 0.206). Conclusion: The present findings suggest that the self-adhesive sealant and the GIC sealant that were exposed to TLC had comparable sealing ability and superior sealing characteristics compared to the conventional resin-based sealant. A long-term clinical trial is needed to assess the intra-oral performance.

Evaluation of Sealant Penetration in Relation to Fissure Morphology, Enamel Surface Preparation Protocol and Sealing Material.

The objective was to assess the effect of fissure depth and enamel surface preparation protocols on penetration of resin-based, giomer and glass-ionomer fissure sealants. Ninety extracted third molars were assigned into three groups according to the material used. All three groups were subsequently divided depending on tooth preparation: no pretreatment or surface preparation with 10% polyacrylic acid, 37% phosphoric acid, or self-etching adhesive. In addition, Er,Cr:YSGG laser or air abrasion were employed in all subgroups. The penetration was evaluated using scanning electron microscopy. The groups that were pretreated with an appropriate acid resulted in superior penetration of glass-ionomer and resin-based sealants when compared with other surface preparation protocols (p < 0.05). The exception was teeth treated with both air abrasion and acid etching. Both preparation protocol and fissure depth significantly affected the sealant penetration (p < 0.05), but fissure depth had a greater impact on fissure penetration than did enamel surface pretreatment. All investigated materials exhibit similar properties regarding sealant penetration. Penetration of a fissure sealant is significantly influenced by the fissure depth. In regard to enamel surface preparation protocol, a pretreatment with phosphoric acid in resin-based and polyacrylic acid in glass-ionomers appears to be essential in obtaining the adequate penetration of a sealing material.

Sealants revisited: An efficacy battle between the two major types of sealants – A randomized controlled clinical trial

The aim of this study is comparing the retention and caries preventive effect of the glass-ionomer fissure sealant and resin-based fissure sealant. A randomized-controlled split-mouth study was conducted to compare the retention and the caries preventive effect of light-cured resin-based sealant (3M ESPE) and glass ionomer sealant (Fuji VII). The sealants were applied to either the right or the left lower mandibular molars (7-9 yrs of age) in 120 school children, based on the randomization process. They were recalled for assessment of clinical retention at intervals of 3, 6, and 12 months. The caries-preventive effect between the two materials was tested statistically by the McNemar's test for matched pairs, and the differences observed with regard to the retention of the materials was tested by Chi-square tests. The level of significance was set to be at P < 0.05. At the end of 12th month, sealant retention is found to be higher in the resin-based sealant group compared to the glass ionomer group. In the glass ionomer sealants placed, 101 (91%) were caries-free and 10 (9%) had caries. In the resin-based sealant, 105 (94.60%) had sound teeth and 6 (5.4%) had dental caries (P = 0.34). The glass ionomer sealant was less retentive when compared to resin sealants. The caries incidence between the glass ionomer and resin-based sealants was not statistically significant.

Glass-ionomer fissure sealants: Clinical observations up to 13 years

ObjectivesThe aim of this study was to clinically examine the retention and caries-preventive effect of a glass-ionomer material for fissure sealing in newly erupted permanent molars. MethodsA total of 1736 newly erupted permanent molars were sealed in 480 children aged 5–15 years. Sealants were evaluated yearly and recorded as “completely retained”, “partially retained”, or “completely lost”. Teeth were also evaluated for presence of caries. ResultsSealants were observed for 2–13 years. The mean follow-up time was 5 years. After one year, 69% of the sealants were fully retained and 21% were partially retained. Thereafter, the cumulative retention rate decreased. Starting from 8th year of follow-up, no “completely retained” sealant could have been observed. At the end of the 13-year follow-up period, 76% of sealants were “completely lost”. On the other hand, 99% and 65% of observed occlusal surfaces were caries-free after one and 13 years, respectively. During the observation period, 62 teeth developed caries in surfaces other than occlusal. Survival rates were significantly better for second permanent molars than for first permanent molars (p < 0.001). No influence of caries risk on caries incidence has been noted. ConclusionsAlthough the retention rate of the glass-ionomer material for fissure sealing was low, it appears to have prevented dental caries in 65% of newly erupted permanent molars evaluated after thirteen years of placement. Clinical significanceThe present study reports long-term clinical performance of glass-ionomer fissure sealants in patients with low, moderate and high caries-risk. The study shows that caries risk does not influence survival of glass-ionomer sealants, which proved to be beneficial for long-term caries protection.

IN VITRO EVALUATION OF WEAR RESISTANCE OF DIFFERENT FISSURE SEALANTS AFTER AGING PROCEDURES

Objective: The purpose of this study is to evaluate the ability of unfilled resin based sealant (Clinpro), glass ionomer fissure sealants (Fuji Triage) and nanofilled resin based fissure sealant (Tetric N-Flow) to resist surface degradation using chewing simulator combined with thermocycling. Methodology: A total of 30 disk shaped specimens were prepared, 10 disks for each material. Surface roughness (Ra) and weight loss were quantitatively measured after 2-body wear testing by using a chewing simulator ‎integrated with thermocycling. Data were statistically analyzed using one-way ANOVA and Bonferroni’s post-hoc test (P ≤ 0.05)Result: Both unfilled resin based sealant (RS) and glass ionomer fissure sealant (GI) showed statistically significant higher (Ra) than nanofilled resin based fissure sealant (NS) before aging procedure. After chewing simulator and thermocycling; there was no statistically significant difference between the (Ra) of three fissure sealant materials. As regard to weight loss (GI) showed the highest mean weight loss followed by (RS) while (NS) showed the lowest mean weight loss. Conclusion: nanofilled resin based fissure sealant showed good resistance to surface degradation compared to other sealants.

Report on the clinical technique of thermo-curing glass-ionomer sealant.

Controversy exists regarding the general safety of resin sealants and in particular their use in children, due to the possible leaching of non-polymerized monomers including bisphenol A. A thermally cured high-viscosity glass-ionomer cement (GIC) is suggested as a first-choice sealant material. An innovative approach of thermo-curing the GIC during placement is presented. The step-by-step clinical procedure and rationale for the biomimetic thermo-cured glass-ionomer fissure sealant are introduced and described. A thermally cured GIC sealant may provide long-term caries protection to fissures and pits without the need to maintain and reseal. GICs are both biocompatible and biomimetic resulting in formation of fluorapatite, the ultimate protection against dental caries.

A comparative study of fluoride release from two different sealants.

Objectives: The introduction of fluoride releasing sealants and glass ionomer cements as fissure sealants adds another dimension to prevention of pit and fissure caries. The ability of resin sealants and glass ionomer cements to release fluoride on a long term basis to the sealed enamel and the adjacent unsealed pit and fissure and cuspal incline enamel may allow for further reduction in pit and fissure caries experience for children. Hence, the study was conducted to compare the amount of fluoride release in the plaque after placing fluoride releasing pit and fissure sealants and glass ionomer fissure sealants used in Atraumatic Restorative Treatment (ART) approach. To compare the fluoride release of both the materials at the different time intervals. Material and Methods: A total of 60 school going children were included in this study. Before application of the sealants, baseline plaque fluoride levels were estimated from all the study subjects. After application of sealants again the same was estimated at an interval of 24 hour, 9 days, 2 weeks and 4 weeks. Results: The peak plaque fluoride levels were achieved at 24 hours after application of fissure sealants in all the groups. Conclusions: Within the limitation of the study, the present study indicated that fluoride releasing fissure sealants may act as a source of fluoride in plaque which will help in preventing pit and fissure and smooth surface caries in the tooth sealed with fissure sealants. Key words:Plaque fluoride, pit and fissures sealants, dental caries.

Scanning electron microscope analysis of sealant penetration and adaptation in contaminated fissures

The objective of this study is to evaluate the penetration and adaptation of two different sealant materials applied under different conditions of contamination using scanning electron microscope (SEM) analysis. A total of 56 extracted human third molar teeth were randomly assigned into eight equal groups. The treatment groups were defined by the combination of two sealant materials (glass ionomer fissure sealant "Fuji Triage" or resin-based fissure sealant "Clinpro TM") and four surface conditions (dry condition, water contamination, saliva contamination or saliva contamination and air-drying). Penetration depth, sealant adaptation and fissure types were evaluated under SEM after sectioning the teeth. Tukey's test and multiple linear regression analyses were used for statistical analysis. No significant difference in the sealant penetration and adaptation was found between both materials under dry conditions. However, under wet contaminations, resin-based sealant showed less adaptation and penetration with a significant difference when compared to glass ionomer sealant (P < 0.05). The multiple linear regression analyses revealed significant impact of different materials and types of contamination on the sealant penetration and adaptation. Glass ionomer sealant has better fissure penetration and more intimate adaptation than resin-based sealant under wet contamination conditions.

Microleakage, adaptation ability and clinical efficacy of two fluoride releasing fissure sealants

Retention of fissure sealants and good adaptation to enamel are essential for their success. Fluoride releasing resin-based materials are widely accepted for pit and fissure sealing, but newly designed glass ionomers can serve as a good alternative. The aim of this study was to evaluate microleakage and sealing ability in vitro, and to clinically assess two fluoride releasing fissure sealants. The sample for experimental study consisted of 20 freshly extracted intact human third molars, divided in two experimental groups according to the sealing material: fluoride releasing resin-based (Heliosel F) and glass ionomer (Fuji Triage) material. Digital images and scanning electron microscope were used to assess microleakage and adaptation ability. Sample for clinical study consisted of 60 children, aged 6-8 years, with high caries risk, divided in two groups according to the sealant material. Fissure sealant was applied to all erupted, caries-free first permanent molars. Sealants were evaluated after 3, 6 and 12 months using modified Ryge criteria for retention, marginal adaptation, colour match, surface smoothness and caries. Microleakage was detected in more than half of the specimen, without significant differences between the two groups (p > 0.05). Both materials exhibited acceptable sealing ability. Complete retention at the end of the observation period was 81.8% for resin-based, and 21.1% for glass-ionomer fissure sealant (p < 0.001). The presence of caries in sealed molars has been detected in one patient in both groups. During the 12-month observation period, Helioseal F demonstrated better retention, marginal adaptation and surface smoothness (p < 0.001). There were no differences between the two materials regarding caries and color match (p > 0.05). Both tested materials demonstrate satisfactory clinical and caries prophylactic characteristics that justify their use in contemporary preventive dentistry.

The impact of fissure depth and enamel conditioning protocols on glass-ionomer and resin-based fissure sealant penetration.

To evaluate the effect that fissure depth and enamel conditioning protocols have on penetration abilities of resin-based and glass-ionomer fissure sealants. Fifty extracted human molars were randomized into 10 experimental groups. Conditioning was performed as follows: groups I and VI, no pretreatment; groups II and VII, 10% polyacrylic acid and 37% phosphoric acid, respectively; groups III and VIII, self-etching adhesive; groups IV and IX, Er:YAG laser; groups V and X, Er:YAG laser/10% polyacrylic acid and laser/37% phosphoric acid, respectively. In groups I to V, teeth were sealed with a glass-ionomer material, and in groups VI to X a resin-based sealant was used. The sealed teeth were sectioned and the penetration ability was evaluated using scanning electron microscopy (SEM). Pretreatment with a suitable acid resulted in superior penetration of glass-ionomer and resin-based sealant when compared with other conditioning protocols (p < 0.0001), except for the teeth treated with both Er:YAG laser and acid. Both conditioning protocol and fissure depth significantly affected the sealant penetration (p < 0.0001), but fissure depth had a greater impact on fissure penetration than did conditioning protocol. Resin-based and glass-ionomer sealing materials show similar potential for pit-and-fissure penetration. Penetration of a fissure sealant is largely influenced by the fissure depth. Regarding the conditioning protocol, a pretreatment with a suitable acid is essential to obtain an adequate penetration of a sealing material.

The Tensile Bond Strength of Fissure Sealant to Enamel Treated by Nd-YAG Laser Irradiation with TiO2 Suspension

In pediatric dentistry, treatment is performed mainly for oral health care and prevention of caries. Fissure sealants are often used in clinical practice for prevention of dental caries. The prevention of caries in occlusal fissures is of practical importance, since pits and fissures are more susceptible to caries than any area. It is possible to debride pits and fissures using laser irradiation in order to remove the fissure contents without altering the shape and structure of the fissures. Although the adhesive strength of fissure sealant to enamel may grow weak when a laser is used, there have been no reports regarding the adhesive strength of enamel to fissure sealant after Nd-YAG laser irradiation with 1% TiO2 suspension. Therefore, the authors investigated the tensile bond strength of a commercial fissure sealant applied after Nd-YAG laser irradiation in contact mode with a fiber diameter of 400 μm, 5 pps, laser tip output power of 300 mJ, and with the use of 1% TiO2 suspension. It was revealed that lasers could react to an enamel surface without any special treatment like application of a black pigment to the surface of the tooth when Nd-YAG laser irradiation was performed. Also, the tensile bond strength of TeethmateF1® to the enamel was lower after laser irradiation with 1% TiO2 suspension, whereas that of Fuji III LC® was stable. From the SEM images of the interfaces between the fissure sealant and enamel, it was found that the enamel surface was affected to a depth of approximately 20-30 μm by laser irradiation. It was revealed that when the fissure sealant was applied with laser irradiation, the laser should be precisely irradiated and the use of a glass-ionomer fissure sealant was more effective.

Glass-Ionomer Fissure Sealant May Not Be as Effective as Resin-Based Sealant in Preventing Caries

A field trial of resin-based and glass-ionomer fissure sealants: clinical and radiographic assessment of caries. Poulsen, S., L. Laurberg, et al. Community Dent Oral Epidemiol (2006) 34(1): 36-40. 1b To compare caries-preventive effect of a resin-based sealant (Delton®) and a glass-ionomer sealant (Fuji III ® ). Industry (Colgate-Palmolive Inc, Denmark) Quasi-randomized (split mouth) trial

Prophylactic efficiency of glass-ionomer fissure sealant

One of the most efficient prophylactic measures in caries prevention is sealing pits and fissures. After improvements of physical and mechanical properties, glass-ionomers are frequently used as sealing materials. The aim of this study was to evaluate the prophylactic efficiency of Fuji VII, a glass-ionomer fissure sealant, through adaptation ability and fluoride reeasing potential assessment using scanning electron microscopic and energy dispersive spectroscopic techniques. The sample consisted of 20 extracted intact human teeth, 10 premolars and 10 molars. Six sections of each tooth were analyzed using SEM. EDS analysis was conducted one week and three months after material placement. The parameters used for the evaluation included: adaptation ability, penetration depth, material structure, integrity of the interfacial zone and ion exchange extent. The sealant penetration depth was observed at 30 X magnification, and the interfacial zone between the material and the enamel at 500-10000 X. EDS was used for quantitative analysis of the material structure, interfacial zone and the enamel surface. The results were statistically analyzed the using chisquare test and descriptive statistical methods. SEM analysis revealed the zone of interaction between the enamel surface and the glass-ionomer with predominant cohesive failures within the sealant material, and satisfactory adaptation ability of the sealing material. The mean value of the penetration was 83% of the total fissure depth, without a statistically significant difference between the tested teeth groups. A lower penetration ability was observed in deep pits and fissures with a larger diameter of unfilled space (p&lt;0.05). EDS analysis revealed the potential of the glass-ionomer for ion exchange with dental tissues. The presence of fluoride ions was detected in 2 sections 3 months after material placement. Glass-ionomers, chemically cured, biocompatible materials demonstrate satisfactory prophylactic characteristics.

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 Vaerlose 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.

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

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). 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. 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). 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.

A Randomised Controlled Trial to Determine the Effectiveness of Glass Ionomer Sealants in Pre-School Children

Background: Caries levels in pre-school children remain high in some areas of the UK. Studies of glass ionomer fissure sealants show their potential for caries prevention in permanent teeth, but their use in primary teeth has not been reported. Aim: To determine whether a glass ionomer fissure sealant placed on primary molars in pre-school children at high risk of developing dental caries can decrease the incidence of dental caries. Material: 508 children aged 18–30 months from high caries areas of South Wales with caries-free first primary molars were recruited to the trial after informed consent. Methods: This was a placebo-controlled individual randomised controlled trial (RCT). All children (n = 508) received a standard package of dental health education. Children in the test group (n = 241) had their first primary molars sealed with glass ionomer. All the children were re-examined once at varying intervals between 12 and 30 months. Results: Analysis of the caries data revealed no significant difference between test and control groups for any of the parameters examined. Examination of the confidence intervals showed no indication that there might be a difference even if the sample size had been increased. Conclusion: There is no evidence that the intervention as used in this population had any effect on caries incidence and it cannot be recommended as a clinical procedure.