Clinical performance of high-viscosity glass ionomer and resin composite on minimally invasive occlusal restorations performed without rubber-dam isolation: a two-year randomised split-mouth study.

OBJECTIVE: The aim of this clinical trial was to evaluate the 2-year clinical performances of high-viscosity glass ionomer and nanohybrid resin composite restorations performed without rubber dam isolation. MATERIALS AND METHODS: Occlusal carious lesions on the right and left mandibular second molars of 56 patients (26 female, 30 male patients) were restored in a split-mouth design. High-viscosity glass ionomer (Hv-GIC) (Equia, GC) and nanohybrid resin composite (GrandioSO, Voco) were used as restorative materials. Clinical evaluations of the restorations were performed according to the Fédération Dentaire Internationale criteria. Data were analysed using the Friedman's analysis of variance and Mann-Whitney U tests (α=0.05). RESULTS: After 2 years, the success rate of Hv-GIC restorations was 96% and that of resin composite restorations was 100%. Hv-GIC showed lower marginal discoloration and greater surface wear and loss of anatomic form (p<0.05). Resin composite showed significantly better surface lustre. CONCLUSION: The 2-year performance of resin composite was similar to that of Hv-GIC for the occlusal restorations of mandibular second molars, in spite of being performed without rubber-dam isolation. CLINICAL RELEVANCE: Saliva contamination can be a clinically significant problem for dental restorations. High-viscosity glass ionomers are a satisfactory alternative to resin composites with the advantage of fast application in such situations. TRIAL REGISTRATION: Clinical Trials Registration number-date: NCT04488380-22/07/2020, retrospectively registered.

Two-Year Survival of High-Viscosity Glass Ionomer in Children with Molar Incisor Hypomineralization.

OBJECTIVE: We assessed the clinical survival of a high-viscosity glass ionomer (HVGI) at the 2-year follow-up to restore molar incisors severely affected by hypomineralization after selective carious tissue removal (SCR). The null hypothesis tested was that there are no differences in the overall survival times in the categories of the variables of interest. METHODS: A total of 134 fully erupted first molar incisors with hypomineralization, cavitated and with moderate-to-deep carious lesions without hypersensitivity or pain (MIH treatment need index 2a-c), were included in the study. HVGI (Equia Forte®; GC, Tokyo, Japan) restorations were applied after SCR to soft carious dentin. The follow-up lasted 2 years. The end point was defined as the absence of endodontic and restorative complications. Two-year, and 18-, 12-, and 6-month survival probabilities and standard errors were calculated using the Kaplan-Meier method. Survival probabilities according to patient gender, jaw, and lesion severity groups were compared using the log-rank test. Restorations were evaluated using the modified US Public Health Service criteria. RESULTS: HVGI restorations showed cumulative survival probabilities of 95.5% at 6 months, 94% at 12 months, 87.5% at 18 months, and 87.5% at 24 months. Survival probabilities according to patient gender, jaw, and lesion severity groups were not statistically significantly different (p > 0.05). Therefore, the null hypothesis was accepted. CONCLUSION: Following SCR, HVGI restoration provided moderate survival probabilities, suggesting that the SCR technique is effective.

Three-year clinical evaluation of high-viscosity glass ionomer restorations in non-carious cervical lesions: a randomised controlled split-mouth clinical trial.

OBJECTIVE: To compare the 3-year clinical performance of high-viscosity glass ionomer restorations with that of composite restorations in non-carious cervical lesions (NCCLs). MATERIALS AND METHODS: One hundred thirty-four NCCLs were randomised into two groups according to a split-mouth design. In the experimental group (Hv-GIC), lesions were restored with a high-viscosity glass ionomer (EQUIA Fil, GC), whereas a composite resin (G-aenial, GC) was applied in the control group (E&Ra/comp). All restorative materials were used according to the manufacturers' instructions. Clinical evaluations were performed after 1 week, 6 months, 1 year, 2 years, and 3 years using FDI (World Dental Federation) criteria. Data were analysed using Friedman's ANOVA and Mann-Whitney U tests (α = 0.05). RESULTS: While retention rates of the Hv-GIC group were 98.5%, 96%, 91%, and 87% in respective evaluation periods, no retention loss was observed in the E&Ra/comp group at any time. There was a statistically significant difference between study groups regarding the retention criterion in both the second and third years (p = 0.008 and p = 0.003, respectively). Furthermore, there was a statistically significant difference between the groups in terms of surface lustre at the third-year recall, in favour of the E&Ra/comp group (p = 0.022). CONCLUSIONS: The 3-year clinical performance of E&Ra/comp restorations in NCCLs was better than that of Hv-GIC restorations. The most common problems in Hv-GIC restorations were a loss of retention and reduction in surface lustre. CLINICAL RELEVANCE: Although the 3-year clinical performance of Hv-GIC restorations in non-retentive lesions was acceptable, it was worse than in composites. The operator should consider the benefit/loss ratio of Hv-GIC when he/she decides to use this material in non-retentive cavities, especially those that are shallow.

A Randomized, Controlled, Split-mouth Trial Evaluating the Clinical Performance of High-viscosity Glass-ionomer Restorations in Noncarious Cervical Lesions: Two-year Results.

PURPOSE: To compare the two-year clinical performance of high-viscosity glass ionomer (Hv-GIC) restorations in noncarious cervical lesions with nanohybrid composite restorations applied with a three-step etch-and-rinse adhesive (E&Ra/nanoC). MATERIALS AND METHODS: One hundred thirty-four noncarious cervical lesions were included and assigned to two groups according to the split-mouth design. The cervical lesions in the experimental group were restored with an Hv-GIC (Equia, GC), while a nanohybrid composite (G-aenial, GC) with a three-step etch-and-rinse adhesive (Optibond FL, Kerr) was applied as the control. All tested restorative materials were used according to the manufacturers' instructions. Clinical evaluation was performed after one week, six months, one year, and two years using World Dental Federation criteria. Data were analyzed using Friedman's ANOVA and Mann-Whitney U-tests (α = 0.05). RESULTS: After two years, Hv-GIC restorations had a retention rate of 91% in comparison to 100% for E&Ra/nanoC restorations. Significant differences existed between the two restorative materials solely with respect to the retention parameter after two years (p = 0.008). CONCLUSIONS: The two-year clinical performance of Hv-GIC was clinically acceptable. However, the retention of E&Ra/nanoC restorations was significantly better than that of Hv-GIC restorations after two years.

Five-year clinical follow-up of bulk-fill restorative materials in class II restorations.

This study evaluates the 5-year clinical performance of Class II restorations performed with different bulk-fill restorative materials. In the study, Class II restorations performed with Tetric Bulk-Fill (TBF), Filtek Bulk-Fill (FBF), and Equia Forte Fil (EF) were evaluated. One hundred-nineteen restorations were included in the study. Restorations were assessed during the 6th month, 1st, 2nd, and 5th year. Cochran Q, Pearson chi-square, and Fisher-Freeman-Halton tests were used for statistical analysis. In the 5th year, significant differences were observed in terms of retention, color match, marginal adaptation, marginal discoloration, surface texture, and anatomical form in all materials. There was a significant difference between EF and bulk-fill composites only in terms of retention and anatomical form. EF was significantly less successful than bulk-fill composites with regard to retention and anatomical form, but bulk-fill composites have shown similar clinical performance. EF cannot be an alternative to bulk-fill composites for Class II restorations.

Organic antibacterial modifications of high-viscosity glass ionomer cement for atraumatic restorative treatment: A review.

High viscosity glass ionomer cement (HVGIC) has been employed as a restorative material for Atraumatic Restorative Treatment (ART). As residual caries persist after caries removal in ART, the antibacterial activity of HVGIC gains importance. Organic and inorganic substances with antibacterial properties have been incorporated into HVGIC over the years, and their effects on the antibacterial and physical properties have been studied. The objective of this paper is to review the various alterations made to HVGIC using organic compounds, their effect on the antibacterial activity, and the physical properties of the cement. Various in vitro investigations have been conducted by adding antiseptics, antibiotics, and naturally occurring antibacterial substances. Most of these compounds render superior antibacterial properties to HVGIC, but higher concentrations affect physical properties in a dose-dependent manner. However, some naturally occurring antibacterial substances, such as chitosan, improve the physical properties of HVGIC, as they enhance cross-linking and polysalt bridging. There is potential for clinical benefits to be gained from the addition of organic antibacterial compounds to HVGIC. In-depth research is required to determine the optimum concentration at which the antibacterial effect is maximum without affecting the physical properties of the cement.

Clinical Effectiveness of High-viscosity Glass Ionomer Cement and Composite Resin as a Restorative Material in Primary Teeth: A Systematic Review of Clinical Trials.

Aim: This systematic review was designed to compare the clinical effectiveness of high-viscosity glass ionomer cement (HVGIC) restorations to direct composite resin (CR) restorations in single- or multisurface cavities in primary teeth. Background: Restorative procedures are typically used to treat caries in primary teeth. Due to their improved preservation of the natural tooth structure and their adhesion to the remaining tooth structure, CR and GIC have drawn attention as the preferred restorative materials. In the literature, over the past 20 years, the term HVGIC has developed. Compared to C-GICs, HVGICs appear to have a higher survival rate. However, isolated studies provide contradictory findings regarding the durability of restorations in primary teeth. Materials and methods: Major electronic databases were thoroughly searched to find publications from the years 2000 to 2021. Studies included were randomized and nonrandomized clinical trials on children aged 3-13 years, in which restoration of primary teeth using HVGIC and CR was performed. Results: This systematic review includes four studies [three randomized controlled trials (RCTs) and one nonrandomized controlled trial]. No statistically significant difference between these materials was seen in any of the included studies. Conclusion: This systematic review of findings supports the assertion that both HVGIC and CR restorations deliver satisfactory outcomes in terms of clinical efficacy and overall survivability. It was found that, for both materials, class I restorations had statistically higher survival rates than class II restorations. Long-term studies are essential to evaluate the clinical efficacy of both restorations. Clinical significance: This systematic review outlines the application of HVGIC and CR as restorative materials for pediatric dentists to use in their everyday dental practices. How to cite this article: Krishnakumar K, Kalaskar R, Kalaskar A, et al. Clinical Effectiveness of High-viscosity Glass Ionomer Cement and Composite Resin as a Restorative Material in Primary Teeth: A Systematic Review of Clinical Trials. Int J Clin Pediatr Dent 2024;17(2):221-228.

Clinical Performance of Zirconia Reinforced versus Conventional Viscous Glass Ionomer in Class I Cavities of Geriatric Patients: A 1-year Randomized Controlled Clinical Trial.

Background: For the elderly population, efforts are made to simplify the restorative procedure while maintaining good clinical performance. Glass ionomer (GI) cements are showing signs to fulfill many of these qualities. With their new properties and ease of use, they can be developed further to become a useful group of materials to overcome the problems of elderly patients. Aim: The aim of the study was to evaluate the clinical performance of zirconia-reinforced versus conventional viscous GI restorations in Class I cavities of geriatric patients. Setting and Design: The study design was in vivo randomized clinical trial, parallel-arms, allocation ratio: 1:1. Subjects and Methods: A total of 28 Class I carious lesions in 21 geriatric patients were restored randomly either by zirconomer-improved or Ketac Molar Quick Aplicap (n = 14) each. Restorations were evaluated for 1 year by modified USPHS criteria. Statistical Analysis: Data were analyzed with the Chi-square test and Cochran's Q-test. Survival rate was analyzed using the Kaplan-Meier and log-rank test. Results: Twenty-four restorations were evaluated in 19 patients with a recall rate of 85.7% at 12 months. Significant differences were found in marginal integrity and marginal discoloration within both restorative materials between different time intervals (P < 0.05). However, none of the materials were superior to another regarding all assessed criteria. Conclusions: Both zirconia-reinforced GI and conventional highly viscous GI have acceptable clinical performance.

The clinical success of ART restorations and Hall technique in primary molars: a randomized 18-month follow-up study.

Objectives: The aim of the study was to evaluate the clinical and radiographic success of the Hall technique (HT) and atraumatic restorative treatment (ART) restorations using high-viscosity glass-ionomer cement for the management of occlusal carious lesions in primary molars. Materials and Methods: This randomized clinical study observed 40 children (aged 5-6 years). For each child, one tooth was treated with HT and one with ART. The primary outcome measures for HT restorations were successful, minor, and major failure rates. Clinical evaluations of ART restorations were performed according to the modified United States Public Health Service criteria during 18-month follow-up. McNemar test was used for statistical analysis. Results: Thirty of 40 (75%) participants returned for 18 months of follow-up. In the clinical evaluations of teeth that were treated with HT, the patients did not have complaints of pain or other symptoms, all crowns remained in the oral cavity, the gums were healthy, and the teeth were functional in all evaluations. At the end of the 18-month follow-up, the surface texture and marginal integrity criteria of ART restorations were recorded as 26.7% and 33.3%, respectively. In the radiographic evaluation of 30 patients treated with ART and HT, all restorations were considered successful. Conclusions: The 18-month clinical and radiographic results after treatments applied to single-surface cavities in anxious children showed that both treatment methods were successful.

Effects of Protective Surface Coating on Fluoride Release and Recharge of Recent Uncoated High-Viscosity Glass Ionomer Cement.

The ability to release and recharge fluoride is a property of glass ionomer cement materials, which is an advantage for patients with a high caries risk. The purpose of this study was to evaluate the amount of released and recharged fluoride in recent uncoated high-viscosity glass ionomer cement (KetacTM Universal AplicapTM) with different surface coatings and at different time points. In total, 135 cylindrical-shaped specimens were equally divided into the following three groups: KetacTM Universal AplicapTM, KetacTM Molar AplicapTM, and KetacTM Fil Plus AplicapTM. The different coatings performed on each group were as follows: uncoated, coated with KetacTM Glaze, and coated with G-Coat PlusTM. The amounts of released and recharged fluoride were measured at 24 h and at weeks 1, 2, 3, and 4. The recharging agent was a 1.23% APF gel. KetacTM Universal AplicapTM showed the highest released fluoride at all time points and the highest recharged fluoride at weeks 1, 2, and 3. Both the KetacTM Glaze- and G-Coat PlusTM-coated specimens presented significantly lower released and recharged fluoride ions than the uncoated group at all time points (p < 0.001). Coating with G-Coat PlusTM significantly decreased the released and recharged fluoride compared to the coating with KetacTM Glaze at almost all time points (p < 0.05), except for weeks 1 and 2. The application of coating agents reduced the amount of released and recharged fluoride by the KetacTM Universal AplicapTM.

One-year clinical evaluation of two high-viscosity glass-ionomer cements in class II restorations of primary molars.

BACKGROUND: Little information exists on the clinical performance of restorative materials on primary teeth of preschool children. This study aimed to evaluate clinical performance of compomer, glass-hybrid-added high-viscosity glass-ionomer cement and zinc-added high-viscosity glass-ionomer cement materials in class ΙΙ restorations of primary molars. METHODS: The study included 251 teeth of 57 patients aged 4-7 years with proximal caries in primary molars. The teeth were divided into three groups, and each restorative material was randomly distributed. Dyract XP, Equia Forte and ChemFil Rock materials were placed after cavity preparation and clinically evaluated at 3, 6, 9 and 12 months using modified United States Public Health Service criteria. Statistical analyses were performed using chi-square and z tests. RESULTS: At the end of 12 months, a total of three restorations in Dyract XP group, 22 in Equia Forte group and 11 in ChemFil Rock group failed in retention criteria. No statistically significant difference existed between retention, colour match and surface texture criteria of all groups at 3 and 6 months, but a statistically significant difference was found at 12 months (P < 0.05). CONCLUSION: For class ΙΙ restorations of primary molars, the success of compomer material was superior to high-viscosity glass-ionomer materials.

Quality of approximal surfaces of posterior restorations in primary molars.

PURPOSE: To evaluate the influence of the restorative material and matrix system on proximal contact tightness and morphological characteristics of class II restorations in primary molars. METHODS: Occluso-mesial cavities in second primary artificial molars were randomly restored using different materials (Filtek Z500 or Filtek Bulk Fill composites or high-viscosity glass ionomer cement Ketac Universal) and different matrix system (Tofflemire, AutoMatrix, matrix band with ring, contoured sectional matrix) (n = 12). Proximal contact tightness was measured using a custom-made device in an Instron 3345, and proximal surface morphology and marginal adaptation were scored after digital scanning. Two-way ANOVA, Tukey and Fischer's exact tests were performed (P < 0.05). RESULTS: Proximal contact tightness values were significantly influenced by the restorative material (P < 0.05), the matrix system (P < 0.001), and their interaction (P < 0.01). Both resin composites showed statistically differences in proximal shape according to the matrix used to restore and exhibited overhanging margins. Ketac Universal restorations showed similar morphology and gaps on the margins regardless of the matrix system. CONCLUSIONS: Overall, both composite restorations achieved tighter proximal contact than those restored with the high-viscosity glass ionomer cement. None of the matrix systems tested provided a convex seamless proximal morphology.

In vitro wear of (resin-coated) high-viscosity glass ionomer cements and glass hybrid restorative systems.

OBJECTIVES: The aim of the present study was to investigate the volumetric abrasive wear of a high-viscosity glass ionomer cement (hvGIC; Equia Fil) and a glass hybrid restorative system (ghRS; Equia Forte), each being recommended as amalgam alternatives. Both materials were applied with or without their respective resinous coating, and were compared with a conventional GIC (Ketac Fil) and a hybrid composite resin (CR; G-ænial Posterior). METHODS: 78 standardized occlusal Class I cavities were restored with the various materials (n = 13 per group). Before and after chewing simulation (30,000 cycles at 40 N), each sample underwent optical scanning procedures (Omnicam). A comparison of the total wear using a fluorescence-aided identification technique (OraCheck) followed, and differences (α = 5%) between groups were compared by means of MANOVA. RESULTS: Regarding the wear rates of hvGIC and ghRS, no differences could be observed (p > .050), and this was not affected by the resinous coating. All hvGIC and ghRS restorations showed significantly higher abrasive wear than CR (p < .001), while the conventional GIC displayed a significant underperformance compared with any other material (p < .001). CONCLUSIONS: Resinous coating of hvGIC or ghRS does not appear to exert an effective long-term protection against advanced abrasive wear. Compared to the conventional GIC showing a considerable substance loss, both hvGIC and ghRS materials revealed an improved abrasion resistance, but clearly failed to meet the excellent values of the CR. CLINICAL SIGNIFICANCE: Occlusal loading should be carefully considered when using hvGIC or ghRS as amalgam (or composite resin) alternatives for the restoration of posterior teeth.

Shear bond strength and interfacial analysis of high-viscosity glass ionomer cement bonded to dentin with protocols including silver diammine fluoride.

PURPOSE: High-viscosity glass ionomer cements (HV-GICs) are reinforced with ultrafine, highly reactive glass particles, as well as a higher-molecular-weight polyalkenoic acid component. Silver diammine fluoride (SDF) is an agent with promising activity against active caries. The present study aimed to evaluate the shear bond strength (SBS) and interfacial morphology of a new HV-GIC bonded to dentin after treatment with various adhesive protocols including SDF. METHODS: HV-GIC cylinders were bonded to dentin after various surface treatments (6 groups, n = 22): water; polyalkenoic acid; SDF; SDF + potassium iodide (KI); SDF + KI + polyalkenoic acid; SDF + KI + two weeks of storage in water + polyalkenoic acid. For each group, 20 samples were tested for SBS after 48 h, and 2 samples were cut and subjected to environmental scanning electron microscopy (E-SEM) and energy-dispersive X-ray (EDX) analysis. RESULTS: No significant differences in SBS were found between any of the protocols tested. However, E-SEM and EDX images showed different interfaces when SDF was applied. CONCLUSION: SDF has no influence on the adhesion of HV-GIC to sound dentin and could potentially improve the cario-resistance of the dentin/HV-GIC interface.

Atraumatic Restorative Treatment and Interim Therapeutic Restoration: A Review of the Literature.

This review discusses the techniques and uses of atraumatic restorative treatment (ART) and interim therapeutic restoration (ITR) and states the differences between these two approaches. ART and ITR are similar approaches and are performed using the same material, but they differ in the purpose of their use. ART is used in cases when there are obstacles to reaching dental care units and has been proven to have high success rates in primary and permanent dentitions. ITR is used as a temporary restoration that will be replaced with a more definitive one. ITR is used in cases when the ideal dental treatment cannot be performed. Conventional glass polyalkenoate (ionomer) restorative cement (GIC) is the material of choice that has been used for ART and ITR. This is because of its fluoride release properties, including its ability to bond to enamel and dentine, its pulpal biocompatibility, and its ease of manipulation. High-viscosity glass ionomer performed better than low and medium-viscosity glass ionomer in ART. Combining GIC with conditioner, as well as the use of a chemo-mechanical approach, improved the success rate of ART. Both ATR and ITR are acceptable strategies, with success rates comparable to the traditional treatment methods.

Survival of occlusal ART restorations using high-viscosity glass-ionomer with and without chlorhexidine: A 2-year split-mouth quadruple-blind randomized controlled clinical trial.

The study question was whether the use of high-viscosity glass-ionomer with chlorhexidine (HVGIC/CHX) for the Atraumatic Restorative Treatment (ART) prepared cavities could achieve a higher restoration survival percentage and be more effective for preventing dentine carious lesions adjacent to the restoration than the use of HVGIC without CHX. The study followed a split-mouth, quadruple-blind, randomized controlled clinical design and lasted 2 years. Patients with at least two small- to medium-sized occlusal cavities were included. The occlusal cavities were prepared according to the ART method and restored with HVGIC/CHX (test) and HVGIC (control). A replica of all restorations available and digital photographs were fabricated at baseline and after 0.5, 1, 1.5 and 2 years and evaluated by two examiners using the ART and Federation Dentaire International (FDI) restoration assessment criteria. Survival curves were constructed using the Kaplan-Meier method, and the log-rank test was used to test for significance between the survival percentages. A total of 100 subjects with an average age of 14.4 years participated. According to the ART restoration assessment criteria, the 2-year survival percentages of ART/HVGIC/CHX (96.8%) and ART/HVGIC (94.8%) did not differ significantly and no significant difference was found between the test (97.9%) and control (96.9%) groups according to the FDI restoration assessment criteria. Eight and five occlusal restorations failed according to the ART and FDI restoration criteria, respectively. No dentine carious lesions along the restoration margin were observed. The 2-year survival of ART restorations in both groups was high. The development of carious dentine lesions adjacent to the restoration was not observed in either treatment group. There is no evidence for modifying HVGIC by incorporating chlorhexidine in order to prevent dentine carious lesion development or to improve the survival of ART restorations in occlusal surfaces in permanent teeth. HVGIC without chlorhexidine can be used successfully to restore occlusal 'ART-prepared' cavities in permanent teeth.

High-viscosity glass-ionomer cements for direct posterior tooth restorations in permanent teeth: The evidence in brief.

OBJECTIVES: To provide a brief overview of the current evidence-base for direct posterior tooth restorations in permanent teeth placed using high-viscosity glass-ionomer cement (HVGIC). METHODS: The evidence sources: laboratory trials, uncontrolled clinical trials, controlled clinical trials with HVGIC restorations placed after conventional cavity preparation by drill and controlled clinical trials with HVGIC restorations placed following the atraumatic restorative treatment (ART) approach, were assessed based on systematic reviews and meta-analyses, as well as methodological studies. RESULTS: The precision and validity of evidence from laboratory trials, uncontrolled clinical trials and non-ART controlled clinical trials are insufficient for clinical guidance. Clinical evidence for HVGIC restorations placed using ART, comprises of 38 controlled clinical trials including over 10 000 tooth restorations. Systematic review results of these trials indicate no statistically significant differences (p>0.05) in the failure rates between HVGIC and amalgam restorations in single- and multiple surface tooth cavities after up to six years. Although, many of these trials suffered from too low sample sizes, their results could be pooled in three meta-analyses. The bias risk in all trials was judged to be high. CONCLUSION: Controlled clinical trials with HVGIC restorations placed using ART provide the bulk of the available evidence that suggest that the failure rate of direct posterior HVGIC restorations in permanent teeth are comparable to that of dental amalgam restorations.

Comparative evaluation of microleakage of nano-filled resin-modified glass ionomer: An in vitro study.

OBJECTIVE: This in vitro study evaluated the microleakage of a nano-filled resin-modified glass ionomer and a high viscosity glass-ionomer restorations in class V cavities. MATERIALS AND METHODS: Thirty-two class V cavities prepared on the buccal and lingual surfaces of 16 sound, third molar teeth were randomly assigned into two groups and restored by one of the glass ionomer material; Group A: A high viscosity (Ketac Molar, 3M ESPE) Group B: A nano-filled resin-modified (Ketac N100, 3M ESPE) glass ionomer. One clinician prepared all the cavities. The materials were used according to the manufacturers' recommendations. The restored teeth were then stored in distilled water at 37°C for 24 h, thermocycled at 5-55°C for 1000 cycles. The specimens were immersed in aqueous solution of Indian ink dye for 48 h at room temperature. They were embedded in resin polyester and sectioned longitudinally in a buccolingual direction. Microleakage was assessed according to the depth of dye penetration along the restoration. The extent of dye penetration at the occlusal and gingival margins was assessed using a stereo microscope. Randomly selected samples from each group were prepared for scanning electron microscope evaluation. The data were statistically analyzed with Friedman and Wilcoxon signed ranks tests. RESULTS: There were statistically significant differences between the microleakage scores of the two groups for both occlusal and gingival scores (P = 0.001). Occlusal and gingival scores for high viscosity glass ionomer (P = 0.024) and nanoionomer (P = 0.021) using Wilcoxon signed ranks tests showed statistically significant differences. High viscosity glass ionomer showed significantly less microleakage compared to the nano-filled resin-modified glass-ionomer (RMGIs) at occlusal margin (P = 0.001). No significant differences were found between the groups at gingival margin (P = 0.0317). CONCLUSION: Within the limitations of this in vitro study, nano-filled RMGIs restorations did not perform better than high viscosity glass ionomer in class V cavities in terms of microleakage assessment.