High-viscosity Glass Ionomer Cement Research Articles

Effect of Surface Treatments on Shear-bond Strength of Glass Ionomer Cements to Silver Diamine Fluoride-treated Simulated Carious Dentin.

This study investigated the effect of different surface treatments on the shear bond strength (SBS) and failure modes of self-cured (SC) and light-cured (LC) high-viscosity glass ionomer cements (HVGICs) to silver diamine fluoride (SDF)-treated simulated carious dentin (SCD). Extracted human premolars were sectioned and pH cycled for 10 days to simulate carious dentin. The demineralized specimens were treated with 38% SDF (Riva Star) for 2 minutes, washed, stored in deionized distilled water at 37°C for 2 weeks, and subjected to the following surface treatments (n=14): T1 - no treatment (control); T2 - 10 seconds polyacrylic acid (PAA); T3 - 5 seconds phosphoric acid (PPA); T4 - 5 seconds PPA plus universal adhesive (Zipbond); and T5 - 5 seconds PPA plus resin-modified GIC adhesive (Riva bond LC). SC (Riva Self-cure HV) and LC (Riva Light-cure HV) HVGICs were applied to the conditioned specimens and stored in artificial saliva at 37°C for 1 week. SBS and failure modes were subsequently determined. Statistical analyses were performed using Kruskal-Wallis/post-hoc Mann-Whitney U and Chi-square tests (α=0.05). The highest SBS was observed when SC and LC were restored with T2 and T5, respectively. Significant differences in SBS were as follows: SC - T2, T1 > T5, T3; LC - T5, T4, T3 > T2. SC generally exhibited adhesive failures, while LC presented both adhesive and mixed failures. The preferred method for preparing SDF-treated carious dentin before restoration application is PAA for SC and PPA plus RMGIC adhesive for LC HVGICs.

Evaluation of fracture resistance of composite resin and glass ionomer in beveled versus non beveled class II restorations in primary molars: In vitro comparative study

Introduction: The high viscosity Bulk-Fill composite (Tetric N ceram) and high viscosity glass ionomer cement (Equia Forte GIC) are the most used materials in class II cavities of primary molars. They have the advantages of being placed in a single layer of 4mm and therefore allow better ergonomics and speed of use. Until now, we find failures of restorations at the level of class II cavities of temporary teeth and many authors have tested the role of the bevel in improving the mechanical strength of restorations. Objectives: The objectives of this study are: to test the role of the bevel in improving the fracture resistance of Bulk Fill composite restorations versus GIC of class II restorations in primary molars, and to test which material has better resistance to fracture. Methods: One hundred temporary extracted molars are collected and randomly divided into four groups: Group I (non-beveled) and II (beveled) filled with Equia forte. Group III (non-beveled) and IV (beveled) filled with Bulk Fill Ivoclar Tetric N Ceram. The specimens were subjected to thermocycling from 5 to 55° for 10000 cycles. After artificial aging, an axial loading at a speed of 1 mm/min was applied until the specimens fractured. Results: The statistical analysis reveals the following: an average of 442.2 N for group I and 498.80 N for group II. Thus, no statistical difference was observed between the groups restored with Equia Forte (p-value>0.05). Whereas, the resistance to fracture for groups III (901.80N) and IV (2438.33N) with a p-value<0.001 so there is significant difference between the two groups. Conclusions: The bevel improves the fracture resistance of the BulkFilll Ivoclar restorations. Whereas, it does not influence the fracture resistance of the Equia Forte group. Bulk Fill Ivoclar Tetric N ceram has better resistance to fracture than Equia Forte GIC restorations.

The effect of simulated food liquids on the surface structure and solubility of various esthetic restorations

Aims: The aim of this study is to investigate the surface roughness and solubility of restorative materials when exposed to foodstuffs in the oral environment using simulated food liquids as defined by the Food and Drug Administration. Methods: In this study, a total of four esthetic restorative materials were used: one universal compomer (Dyract XP, Dentsply), one conventional microhybrid composite (FiltekTM Z250, 3M ESPE), one nanofilled, and one high-viscosity glass ionomer cement (ChemFil Rock, Dentsply). A total of 160 samples, each 8 mm in diameter and 2 mm in thickness, were prepared using molds. The initial weights of the samples were recorded in micrograms using a precision balance to determine solubility values. Initial surface roughness values were measured using an atomic force microscope device. The samples were immersed in four different simulated food liquids (ethanol, heptane, citric acid, and distilled water) for a period of 7 days. After removal from the solutions, the samples were desiccated to a constant weight, and the second set of weights was recorded. Subsequently, the second surface roughness values were measured Results: Among the materials immersed in the simulated food solutions, ChemFil Rock exhibited the highest solubility and increase in surface roughness. Citric acid was found to be the solution that caused the highest increase in surface roughness values and solubility for this material (p

Addition of nisin to high-viscosity glass-ionomer cement: a comparative in vitro study on antibacterial and physical properties

PurposeNisin is a lantibiotic effective against Gram-positive microorganisms such as Streptococcus mutans. The study aimed to determine the effect of the addition of nisin to high-viscosity glass-ionomer cement (HVGIC) on its antibacterial activity, setting time, surface microhardness, and compressive strength.Methods1 and 3% w/w nisin were added to HVGIC before mixing. Unmodified HVGIC was the control. Agar disc diffusion, direct contact test, and scanning electron microscopy (SEM) analysis were used to evaluate antibacterial activity against S. mutans. Setting time, surface microhardness, and compressive strength were measured using Gilmore needle apparatus, digital microhardness tester, and universal testing machine, respectively. Statistical analysis included Student’s t test, one-way ANOVA with Tamhane’s post hoc test, and repeated-measures ANOVA.ResultsAs evidenced by the agar disc diffusion (p < 0.001), direct contact tests (p = 0.025), and SEM analysis of the S. mutans cell count and cell surface area (p = 0.049 and 0.003), 3% nisin had the strongest antibacterial activity. There was a dose-dependent increase in setting time (p = 0.005) and surface microhardness (p = 0.006), with no significant difference in compressive strength compared to control.ConclusionThe addition of 3% nisin to HVGIC enhances the antibacterial action against S. mutans and surface microhardness without adversely affecting setting time and compressive strength.

Cost-effectiveness of restorative treatments for permanent molars with severe molar incisor hypomineralization: perspectives for the Brazilian public health system.

To undertake a cost-effectiveness analysis of restorative treatments for a first permanent molar with severe molar incisor hypomineralization from the perspective of the Brazilian public system. Two models were constructed: a one-year decision tree and a ten-year Markov model, each based on a hypothetical cohort of one thousand individuals through Monte Carlo simulation. Eight restorative strategies were evaluated: high viscosity glass ionomer cement (HVGIC);encapsulated GIC; etch and rinse adhesive + composite; self-etch adhesive + composite;preformed stainless steel crown; HVGIC + etch and rinse adhesive + composite; HVGIC + self-etch adhesive + composite, and encapsulated GIC + etch and rinse adhesive + composite. Effectiveness data were sourced from the literature. Micro-costing was applied using 2022 USD market averages with a 5% variation. Incremental cost-effectiveness ratio (ICER), net monetary benefit (%NMB), and the budgetary impact were obtained. Cost-effective treatments included HVGIC (%NMB = 0%/0%), encapsulated GIC (%NMB = 19.4%/ 19.7%), and encapsulated GIC + etch and rinse adhesive + composite (%NMB = 23.4%/ 24.5%) at 1year and 10years, respectively. The benefit gain of encapsulated GIC + etch and rinse adhesive + composite in relation to encapsulated GIC was small when compared to the cost increase at 1year (gain of 3.28% and increase of USD 24.26) and 10years (gain of 4% and increase of USD 15.54). Within the horizon and perspective analyzed, the most cost-effective treatment was encapsulated GIC restoration. This study can provide information for decision-making.

Evaluation of the Effect of Different Bonding Systems and Restorative Materials on Shear Bond Strength in the Repair of High-Viscosity Glass Ionomer Cement

Aim: High viscosity glass ionomer cements have been produced to increase the mechanical properties of glass ionomer cements. The aim of this study is to determine the appropriate adhesive system and restorative material that can be used in fracture repair of high viscosity glass ionomer cements. Material and Methods: A total of 140 standard size acrylic blocks were used in the study. 14 groups were formed from randomly selected acrylic blocks, with 10 samples in each group. High viscosity glass iomomer cement was placed in the first 13 groups, and resin-modified glass ionomer cement was placed in the last group. After the thermal cycle aging process was applied to all samples, repair restorations were performed with 4 different adhesive systems, 2 different composite resins and 2 different restorative types of glass ionomer cement. After the repair restorations, thermal cycle aging was applied again and the shear bond strengths were evaluated. One-way analysis of variance and Duncan multiple comparison test were used for statistical analysis. Results: The highest shear bond strength values were obtained by the total etch adhesive system (p&lt;0.001). The lowest shear bond strength values were obtained when high-viscosity glass-iomomer cement without adhesive system was restored with high-viscosity glass iomomer cement (p&lt;0.001). Conclusion: For higher shear bond strength values in the repair of high-viscosity glass ionomer cements should use to total etch adhesive systems and composite resin.

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

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. 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. 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. 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. 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. This systematic review outlines the application of HVGIC and CR as restorative materials for pediatric dentists to use in their everyday dental practices. 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.

Adhesion of glass ionomer cements to primary dentin using a universal adhesive.

Glass ionomers are widely used for restoring carious primary teeth. However, their ability to bond to primary dentin is considered a challenge in pediatric dentistry. The study aimed to evaluate the microshear bond strength (μSBS) of a resin-modified glass ionomer (RMGI) and a high-viscosity glass ionomer cement (Hv-GIC) to primary dentin using a universal adhesive. Thirty human primary maxillary canines were cut in half and prepared for the μSBS test. The specimens (N = 60) were assigned to 6 groups. Three groups were defined for RMGI (FUJI II LC) and 3 groups for Hv-GIC (EQUIA Forte): with an immediately curing adhesive (G-Premio); with a delayed curing adhesive; and without an adhesive (control group). After preparing the dentin surfaces, the glass ionomers were bonded using Tygon® tubes with an internal diameter of 0.7 mm. The μSBS test was performed, and the data was analyzed using two-way analysis of variance (ANOVA) followed by Tukey's post hoc test. Additionally, the failure modes were determined using a stereomicroscope. Six specimens, one for each study group, were prepared for scanning electron microscopy (SEM) analysis to observe the glass ionomer-dentin interface. The type of glass ionomer did not have a significant effect on the μSBS (p = 0.305). Groups that received universal adhesive application prior to glass ionomer exhibited a significantly higher μSBS (p < 0.0001). However, there was no significant difference between the immediately curing and delayed curing groups (p = 0.157). The predominant failure mode was mixed failure. Higher bond strength of glass ionomers to primary teeth can be achieved by using universal adhesives, which, in addition to the proven benefits of glass ionomers, can improve their clinical success.

Effect of ionizing radiation on the mechanical properties of current fluoride-releasing materials.

This study aimed to evaluate the effect of fractional radiation on the mechanical properties of fluoride-releasing materials. High-viscosity glass ionomer cement (F9), resin-modified glass ionomer cement (F2), glass hybrid restoration (EQ), and bioactive composite (AC) were divided into 3 subgroups: 0, 35, and 70 Gy fractional radiation doses. The specimens were subjected to surface roughness, Vickers microhardness, and compressive strength tests. The chemical components and morphology of the tested specimens were observed via energy dispersive spectroscopy and scanning electron microscopy. The data were analyzed using two-way ANOVA with Bonferroni post hoc analysis. After exposure to fractional radiation, the surface roughness increased in all the groups. F9 had the highest surface roughness, while AC had the lowest surface roughness within the same radiation dose. The Vickers microhardness decreased in F9 and EQ. The AC had the highest compressive strength among all the groups, followed by F2. More cracks and voids were inspected, and no substantial differences in the chemical components were observed. After fractional radiation, the surface roughness of all fluoride-releasing materials increased, while the Vickers microhardness of F9 and EQ decreased. However, the compressive strength increased only in F2 and AC.

Evaluating Glass Ionomer Cement Longevity in the Primary and Permanent Teeth-An Umbrella Review.

The aim of this umbrella review was to evaluate the longevity of glass ionomer cement (GIC) as a restorative material for primary and permanent teeth. Research in the literature was conducted in three databases (MedLine/PubMed, Web of Science, and Scopus). The inclusion criteria were: (1) to be a systematic review of clinical trials that (2) evaluated the clinical longevity of GICs as a restorative material in primary and/or permanent teeth; the exclusion criteria were: (1) not being a systematic review of clinical trials; (2) not evaluating longevity/clinical performance of GICs as a restorative material; and (3) studies of dental restorative materials in teeth with enamel alterations, root caries, and non-carious cervical lesions. Twenty-four eligible articles were identified, and 13 were included. The follow-up periods ranged from 6 months to 6 years. Different types of GICs were evaluated in the included studies: resin-modified glass ionomer cement (RMGIC), compomers, and low- and high-viscosity glass ionomer cement. Some studies compared amalgam and composite resins to GICs regarding longevity/clinical performance. Analyzing the AMSTAR-2 results, none of the articles had positive criteria in all the evaluated requisites, and none of the articles had an a priori design. The criteria considered for the analysis of the risk of bias of the included studies were evaluated through the ROBIS tool, and the results of this analysis showed that seven studies had a low risk of bias; three studies had positive results in all criteria except for one criterion of unclear risk; and two studies showed a high risk of bias. GRADE tool was used to determine the quality of evidence; for the degree of recommendations, all studies were classified as Class II, meaning there was still conflicting evidence on the clinical performance/longevity of GICs and their recommendations compared to other materials. The level of evidence was classified as Level B, meaning that the data were obtained from less robust meta-analyses and single randomized clinical trials. To the best of our knowledge, this is the first umbrella review approaching GIC in permanent teeth. GICs are a good choice in both dentitions, but primary dentition presents more evidence, especially regarding the atraumatic restorative treatment (ART) technique. Within the limitation of this study, it is still questionable if GIC is a good restorative material in the medium/long term for permanent and primary dentition. Many of the included studies presented a high risk of bias and low quality. The techniques, type of GIC, type of cavity, and operator experience highly influence clinical performance. Thus, clinical decision-making should be based on the dental practitioner's ability, each case analysis, and the patient's wishes. More evidence is needed to determine which is the best material for definitive restorations in permanent and primary dentition.

Physical and mechanical properties assessment of glass ionomer cements modified with TiO2 and Mg-doped hydroxyapatite nanoparticles.

High viscosity glass ionomer cements (GICs) are widely used in various clinical applications, being particularly effective in atraumatic restorative treatment (ART) due to the synergistic interaction between the material and the technique. However, the inadequate mechanical properties of GICs raise concerns regarding the predictability and longevity of these restorations in areas exposed to occlusal stress. Various modifications of the powder components have been proposed to improve the mechanical strength of GICs to withstand occlusal loading during mastication. In this in vitro study, we investigated whether the nanoparticles (NPs) added to commercially available GICs could fulfill this requirement, which would likely broaden the spectrum of their potential clinical applications. Two commercially available GIC powders (Fuji IX and Ketac Molar), modified by the addition of 5 wt.% TiO2, MgHAp100 or MgHAp1000 NPs, were incorporated into the corresponding liquid in an appropriate ratio, and the mixed cements were evaluated in terms of fracture toughness, flexural strength, Vickers microhardness and rheological tests and compared with the original material. Fuji IX containing 5 wt.% MgHAp100 NPs had lower flexural strength, while Ketac Molar with 5 wt.% TiO2 NPs showed increased fracture toughness. Vickers microhardness increased in Fuji IX following the addition of 5 wt.% TiO2 and MgHAp100 but decreased in Ketac Molar comprising 5 wt.% MgHAp100 (p < 0.05). Achieving a predictable bond between NPs and cement matrix, as well as ensuring a uniform distribution of the NPs within the cement, are critical prerequisites for enhancing the mechanical performance of the original cement.

The Effect of Bevel on Fracture Resistance of GIC Restorations in Primary Molars: An “In Vitro Study”

Introduction: Glass ionomer cements (GICs) are commonly used for restorations in primary molars due to their adhesive, hydrophilic, and bioactive properties. However, their low mechanical resistance may limit their use in proximal cavities. Recent advancements in GICs, such as the high viscosity GIC EQUIA Forte®, have improved their mechanical properties. The effect of a Cavo superficial bevel on the mechanical strength of GIC restorations has been previously studied. Objectives: To investigate the effect of a Cavo superficial bevel on fracture resistance and the type of fracture (adhesive, cohesive, or catastrophic) in EQUIA Forte® GIC restorations in primary molars. Methods: A total of 66 standardized proximal cavities were created on 51 temporary molars. The cavities were randomly divided into two groups: group I without a Cavo superficial bevel (n=33) and group II with a 45° Cavo superficial bevel (n=33). The cavities were restored with EQUIA Forte®. The samples were subjected to thermocycling and artificial aging, then, an axial speed loading of 1 mm/min was applied until fracture. Fracture toughness was recorded, and the type of fracture was observed under an optical microscope. A Mann-Whitney U test was used to compare the average fracture resistance between the groups. All tests were two-tailed and the level of significance was set at 5%. Results: The average fracture resistance for group I was (237.57 ± 139.97 N) and for group II was (294.89 ± 171.07 N). There was no statistically significant difference in fracture resistance between the two groups (p&gt;0.05). Mixed fractures were observed in all samples, with adhesive fractures only present in group I and cohesive fractures only present in group II. Conclusions: The Cavo superficial bevel does not significantly affect the fracture resistance of GIC resto rations in primary molars. However, the bevel design may prevent adhesive and catastrophic fractures.

A Comprehensive Evaluation of Zirconia-Reinforced Glass Ionomer Cement's Effectiveness in Dental Caries: A Systematic Review and Network Meta-Analysis.

Dental cements are in a constant state of evolution, adapting to better align with the intricacies of tooth structure and the dynamic movements within the oral cavity. This study aims to evaluate the efficacy of zirconia-reinforced glass ionomer cement-an innovative variant of modified glass ionomer cements-in terms of its ability to withstand compressive forces and prevent microleakage during dental caries reconstruction. An extensive search was conducted across various databases, encompassing PubMed-MEDLINE, Scopus, Embase, Google Scholar, prominent journals, unpublished studies, conference proceedings, and cross-referenced sources. The selected studies underwent meticulous scrutiny according to predetermined criteria, followed by the assessment of quality and the determination of evidence levels. In total, 16 studies were incorporated into this systematic review and network meta-analysis (NMA). The findings suggest that both compomer and giomer cements exhibit greater compressive strength and reduced microleakage values than zirconia-reinforced glass ionomer cement. In contrast, resin-modified glass ionomer cement (RMGIC) and high-viscosity glass ionomer cement (GIC) demonstrate less favorable performance in these regards when compared with zirconia-reinforced glass ionomer cement.

Evaluation of the Efficiency of Enzyme-Based Chemomechanical Method in Atraumatic Restorative Treatment of Primary Molars

Aim: To compare clinical and radiographic successes and pain dimensions this chemomechanical agent and traditional Atraumatic Restorative Treatment (ART) method. Material and Methods: Children aged 3-8 years who applied clinic with their parents were included our study (n=38). Teeth included study; Traditional ART method with excavator, enamel chisel and probe and chemomechanical carious tissue removal method with Brix 3000 material were applied. After caries removal methods, restorations were completed with high viscosity glass ionomer cement (YVCIS). After restoration applications, evaluation was made according the Wong Baker Pain Scale. The clinical success restorations was followed up 3, 6 and 12 months according the modified USPHS criteria. Radiographic evaluation was performed 6 and 12 months. In whole study, error value was 5% and load was accepted maintaining the p&lt;0.05 value. Results: 3 and 6 months, there was difference marginal compliance criteria between chemomechanical caries removal and YVCIS restorations applied after traditional ART methods, under surveillance (3rd month p=0.040; 6th month p=0.047). YVCIS restorations applied after chemomechanical caries removal method had Charlie score 2.8% in secondary caries criterion 6th month follow-up. In evaluation made with Wong Baker Pain Scale, facial expression representing no pain expression was preferred most both groups. When all results were evaluated between the two groups, no difference was found when removed (p=0.536). Conclusion: Our study; The chemomechanical caries removal method used non-surgical and acceptable caries removal technique similar the conventional ART method.

Evaluation of 38% Silver Diamine Fluoride vs High Viscosity Glass Ionomer Cement for Management of Dentinal Caries in Primary Molars

Evaluation of 38% Silver Diamine Fluoride vs High Viscosity Glass Ionomer Cement for Management of Dentinal Caries in Primary Molars

Efficacy of bioactive materials in preventing Streptococcus mutans-induced caries on enamel and dentine.

The study investigated the ability of bioactive materials used to restore enamel and dentine specimens to prevent caries. Enamel (n=50) and dentine (n=50) specimens were obtained from bovine incisors, prepared, and randomly allocated to one of five groups according to the restorative treatment: alkasite without adhesive system; alkasite with adhesive system; high viscosity glass ionomer cement; resin composite; no restoration; negative control group. Specimens were restored, exposed to a thermal cycling aging protocol, sterilized, and exposed to a cariogenic challenge induced by Streptococcus mutans and then submitted to surface and subsurface microhardness tests and polarized light microscopy to verify the caries lesion development in enamel or dentine surrounding the restorative materials. Data were analyzed using one-way ANOVA. In enamel and dentine, glass ionomer cement, alkasite without and with adhesive system presented a lower percentage surface microhardness loss than resin composite and negative control. Enamel subsurface microhardness presented no statistically significant differences between glass ionomer cement, alkasite without and with adhesive system. Glass ionomer cement also did not present statistically significant differences from resin composite and the negative control. In dentine, glass ionomer cement showed the highest subsurface microhardness values. In conclusion, bioactive restorative materials provide greater protection to enamel and dentine against surface caries development than resin composite.

Trajtimi atraumatik restaurues në stomatologjinë e fëmijëve

Dental caries is one of the most prevalent multifactorial diseases in the world. In the field of dental caries manage- ment, Atraumatic Restorative Treatment is known as a minimal intervention and minimally invasive procedure and has shown to be successful in both, developed and devel- oping countries. The Atraumatic Restorative Treatment is the technique that involves removing carious tooth tissues using hand instruments only, without the use of anesthesia and electrically-driven equipment and restoring the cavity with adhesive restorative material usually a high-viscosity glass-ionomer cement. The Atraumatic Restorative Treat- ment in the single-surface restorations presented high sur- vival percentages in both primary and permanent posterior teeth, while in the multiple-surface restorations presented lower survival percentages. Researchers should focus on im- proving the materials of atraumatic restorative treatment restoration, extending the knowledge of the technique in association with pain and anxiety and encouraging the use of this approach in national oral health care systems.

In Vitro Evaluation of the Bond Strength of Metal Brackets Adhered to Different Dental Restorative Materials using Different Orthodontic Adhesives

ABSTRACT Background: During orthodontic treatment, teeth with brackets may sometimes be restored with different restorative materials. In this case, the content of the orthodontic adhesive selected for bracket bonding may also be important. Aim: This study compared the bond strength of metal orthodontic brackets adhered to different resin composite and glass ionomer cement (GIC) restoration surfaces with glass ionomer-based and resin-based orthodontic adhesives to determine the best orthodontic adhesive for use in restored teeth. Material and Methods: This study prepared 80 discs. Four material groups of 20 discs were created: reinforced high-viscosity GIC, high-viscosity GIC, flowable bulk-fill resin composite, and nanohybrid resin composite. Specimens in each material group were divided into two subgroups that differed in the orthodontic adhesive used to bond the brackets to the prepared specimens. After 24 hours, the specimens were shear bond strength (SBS) tested at 1 mm/min using a universal tester. Results: The SBS of glass ionomer-based orthodontic adhesive differed significantly between metal brackets adhered to different bases (P &lt; 0.001). The highest SBSs were observed between metal brackets and high-viscosity glass ionomer restorations (6.79 ± 2.38). The highest SBSs observed with a resin-based orthodontic adhesive were between metal brackets adhered to nanohybrid resin composite restorations (8.84 ± 2.10; P = 0.030). Conclusions: Glass ionomer-based orthodontic adhesive provided safer bond strength and demineralization prevention when applying metal brackets to teeth with glass ionomer restorations.

Insertion methods and gap/void formation in atraumatic restorative technique: A micro-CT analysis.

Wetting the dentin is critical to atraumatic restorative treatment. The conventional insertion can be challenging when using high-viscosity glass-ionomer cement. This study evaluated the formation of gaps and voids after three insertion methods using micro-CT. Teeth underwent removal of occlusal and proximal caries through the atraumatic restorative treatment technique. Then, they were fixed in an artificial dental arch to simulate the clinical condition and were restored using three insertion methods: conventional, Centrix injection, and double-filling. Previous dentin conditioning procedures, steel matrix and wooden wedge application, and post-insertion procedures (digital compression and surface protection) were the same. The material was inserted using a manual instrument in the conventional technique and was inserted with a syringe in the Centrix injection group. In the double-filling technique, the tooth received a first layer of a flowable ionomer (through modifying the powder/liquid ratio), and a second layer (with standard ratio) was applied before the final set of the first one. A micro-CT unit scanned each tooth before and after restoration. Each cavity was defined as the volume of interest, and the volumes of gaps and voids were calculated. Data were analyzed using one-way ANOVA and Tukey posthoc test (p < .05). Double-filling had improved filling volume with lower values for gap volume, followed by Centrix injection. The conventional technique had the highest gap volume. No statistically significant difference was observed for void volume. Double-filling demonstrated fewer gaps, followed by Centrix injection, which is critical to obtain better adhesive, remineralizing, and antibacterial activities.

Restauração de molares afetados pela Hipomineralização Molar-Incisivo utilizando a técnica da réplica oclusal

ABSTRACT The aim of this study was to report the clinical case of an 8-year-old male patient seen at the Pediatric Dentistry outpatient clinic at the Universidade Federal do Paraná, Brazil, diagnosed with molar-incisor hypomineralization (MIH) after presenting with pain in teeth 16, 36, and 46, which had extensive atypical cavities and opacities on the adjacent enamel. A diagnostic wax-up of affected teeth was performed for manufacture of silicone occlusal matrix. Encapsulated high-viscosity glass ionomer cement was handled and inserted into the occlusal matrix which was fitted onto the teeth by slight finger pressure. After setting time, excess of material was removed, and occlusion was checked. A flowable resin coating material was applied, and the restorations were finished. Six months later, the restorations performed for treatment of the severe MIH lesions proved to be efficient, lowering the sensitivity reported by the patient, reshaping the teeth, improving their function, and refining dental esthetics.