Light-cured Resin-modified Glass Ionomer Research Articles

Combination of Nonsurgical Endodontic and Vital Pulp Therapy for Management of Mature Permanent Mandibular Molar Teeth with Symptomatic Irreversible Pulpitis and Apical Periodontitis

IntroductionThis prospective study evaluated the outcome of a combination of nonsurgical endodontic (NSET) and vital pulp therapy (VPT) for the management of mature permanent mandibular molar teeth with symptomatic irreversible pulpitis (SIP) and apical periodontitis (AP). MethodsInstitutional ethical clearance was obtained. Mandibular molar teeth (N = 60) with a definitive diagnosis of SIP and AP with a radiographic periapical index score (PAI) of ≥3 in either 1 of the roots (mesial or distal) were included. Block randomization was used for allocation. In the NSET group (n = 30), single-visit NSET was performed using a standardized operating protocol. In the NSET-VPT group (n = 30), subsequent to full pulpotomy, at the root orifice where a vital pulp was observed (as determined by the arrest of pulpal bleed upon application of a 2.5% sodium hypochlorite pressure pack), a mineral trioxide aggregate radicular barrier was placed, and it was covered with light-cured resin-modified glass ionomer cement. NSET was performed in the root exhibiting a PAI score ≥3. The tooth was permanently restored. Postoperative pain was assessed at 24, 48, and 72 hours. Teeth were followed up clinically and radiographically at 12 months. The presence/absence of symptoms and the change in PAI scores were noted. The data were statistically analyzed. ResultsThe success rate was 90% in the NSET group and 93.3% in the NSET-VPT group. According to an intergroup comparison between the proportion of teeth healed and nonhealed (radiographic), there was no significant difference (P > .05). ConclusionsThe combination of NSET and VPT is a viable biologically based minimally invasive treatment option for multirooted mandibular teeth with SIP and AP.

Comparison of shear bond strength of light-cured resin-modified glass ionomer and moist insensitive primer on contaminated enamel

Despite rapid developments in adhesive technology, contamination of bonding surfaces remains a major problem. The aim of this study was to evaluate the influence of contamination on shear bond strength of two adhesive systems: resin-modified glass ionomer cement (Fuji Ortho LC; GC America Corp) and Moist Insensitive Primer (Transbond MIP, 3M Unitek) combination with Transbond XT (light-activated), under different enamel conditions. Metal brackets were bonded to the buccal surfaces of 42 human premolars. The total sample was divided into 6 groups (n = 7 teeth) and brackets were bonded with one of the 2 adhesives under 3 enamel surface conditions: (1) dry (2) saliva-contaminated (3) saliva and blood-contaminated. The shear bond strength was tested using Universal Strength Tester Autograph Shimadzu Corp. There was no significant difference in the shear bond strength between dry, saliva, and saliva-blood contamination bonded with MIP combined Transbond XT. There were significant differences in the shear bond strengths between dry and saliva -blood contaminated enamel bonded with Fuji Ortho LC. In conclusion, Fuji Ortho LC is not recommended for clinical bonding application under saliva-blood contaminated enamel conditions.

Effects of Curing Modes on the Microhardness of Resin-modified Glass Ionomer Cements.

ObjectiveThis study evaluated the effects of curing modes on surface microhardness of visible light-cured resin-modified glass ionomer cements (VLC RMGIC) and a giomer after different storage periods in comparison to auto-cured resin-modified glass ionomer cements (AC RMGIC).Materials and MethodsThe following materials were used: VLC RMIC: Fuji II LC Improved, Photac Fil Quick Aplicap, AC RMGIC: Fuji Plus, Fuji VIII and Giomer: Beautifil II. The measurements of microhardness were performed using a Vickers test (100 g loads were applied for 10 s) in the following time intervals: immediately after the recommended cure and after 1, 7 and 14 days of immersion in distilled water. Five samples (d=4 mm, h=2 mm) were prepared for each combination of curing mode and tested material.ResultsAfter 14 days, an improvement of microhardness was evident in all tested materials. The full factorial ANOVA identified a highly significant (p<0.001) effect of the factors “material”, “time” and “curing mode (“low”, “soft“, „high”) for the light-cured materials Beautifil II, Fuji II LC and Photac Fil Quick. There was a statistically significant difference in the microhardness between different material types (Beautifil II˃Fuji II LC˃Photac Fil Quick˃Fuji Plus˃Fuji VIII) and curing modes (low ˂soft ˂high).ConclusionsMaterial type had the greatest impact on microhardness, followed by the factor of time, while curing modes showed a considerably smaller influence on microhardness of the light-cured materials.

Temperature changes in the pulp chamber induced by polymerization of resin-based dental restoratives following simulated direct pulp capping

The objective of this study was to measure temperature changes in the pulp chamber induced by polymerization of resin-based dental restoratives following a simulated procedure of direct pulp capping. Class I cavities with a microperforation at the pulp horn were prepared in extracted human molar teeth. The complete procedure of direct pulp capping and cavity restoration was performed with the root part of extracted teeth fixed in a water bath at 37 ?C. Mineral trioxide aggregate, bioactive dentin substitute or calcium-hydroxide paste were used as pulp capping materials. Cavities were restored with a light-cured or chemically-cured resin-modified glass ionomer, universal adhesive and a bulk-fill composite, cured with a high-intensity LED unit. Pulp capping materials caused a slight temperature decrease. Lower temperature increase was recorded during light-curing of the glass ionomer liner after direct capping with mineral trioxide aggregate and calcium-hydroxide than that recorded for the bioactive dentin substitute. Adhesive light-curing increased temperature in all groups with higher mean temperatures in groups with chemically-cured as compared to those for the light-cured glass ionomer liner. Direct pulp capping with mineral trioxide aggregate or calcium-hydroxide followed by the light-cured resin-modified glass ionomer liner and a bonded bulk-fill composite restoration induced temperature changes below the potentially adverse threshold of 42.5?C.

Study to evaluate the Efficacy of Resin-modified Glass Ionomer Cement Liner as a Direct Pulp Capping Material

The aim of the present in vivo study was to compare efficacy of light-cured resin-modified glass ionomer liner, Vitrebond™ (3M ESPE) with Dycal® (Dentsply) on the healing of pulpal tissue in the event of a direct iatrogenic pulpal exposure. Experimental group consisted of Vitrebond™ (3M ESPE) resin-modified glass ionomer liner, and Vitremer™ (3M ESPE) resin-modified glass ionomer cement (GIC) in comparison with the control group of Dycal® (Dentsply) as liner and Poly F® (Dentsply) dental cement. Class V cavities were prepared in 32 sound premolars that were scheduled for orthodontic extraction, and the exposures were capped according to groups. Five teeth from each group were extracted under local anesthesia after an interval of 24 hours, 35 and 60 days, and evaluated for inflammation, fibrotic changes, formation of reparative dentin and bacterial examination. The present study did not show any statistically significant difference between two groups in terms of inflammation, fibrosis, reparative dentin formation, and bacterial examination. This study shows that Vitrebond™ (3M ESPE) light-cured resin-modified glass ionomer liner can be used as an alternative to calcium hydroxide as a direct pulp capping material. Light-cured resin-modified glass ionomer liner can be an alternative for the calcium hydroxide-based liner for capping iatrogenic pulp exposures.

Cambios en la resistencia compresiva del ionómero de vidrio al ser grabado con ácido ortofosfórico

Introducción: los ionómeros de vidrio resinomodificados son materiales usados como base intermedia en procedimientos dentales. El objetivo fue evaluar los cambios que ocurren en la resistencia compresiva de un ionómero de vidrio resinomodificado después de ser grabado con ácido ortofosfórico al 37%. Materiales y métodos: Estudio experimental in vitro. Se prepararon 40 moldes termoformados, 20 muestras en el grupo experimental (ge) a las que se les aplicó ácido fosfórico durante 15 s y fueron lavadas durante 40 s, y 20 muestras en el grupo control (cg). Diez muestras de cada grupo se almacenaron por 48 horas al baño maría. Todas las muestras fueron sometidas a una fuerza compresiva usando una máquina universal de prueba. El análisis se realizó en el programa estadístico spss versión 19. Se realizaron las pruebas de Tukey y Anova. Resultados: hubo diferencias estadísticamente significativas entre los grupos con y sin ácido a los 15 minutos con respecto a los grupos con y sin ácido a las 48 horas (P = 0,01). Conclusiones: la aplicación de ácido fosfórico al 37% no afecta la resistencia compresiva de los ionómeros de vidrio resinomodificados. La reducción en la resistencia compresiva podría estar asociada al almacenamiento en medio húmedo.

Resin-Modified Glass-Ionomer Cement (RM-GIC) may Provide Greater Caries Preventive Effect Compared with Composite Resin, but High-Quality Studies are Needed

Caries-preventive effect of resin-modified glass-ionomer cement (RM-GIC) versus composite resin: a quantitative systematic review. Yengopal V, Mickenautsch S. Eur Arch Paediatr Dent 2011;12(1):5-14. David G. Pendrys, DDS, PhD. Does light-cured resin-modified glass-ionomer cement provide a better caries preventive effect as compared with composite resin? Information not available. Systematic review. Level 2: Limited-quality, patient-oriented evidence. Grade B: Inconsistent, limited-quality patient-oriented evidence.

Bond strength of orthodontic light-cured resin-modified glass ionomer cement

The purpose of this study was to compare the bond strengths and debonded interfaces achieved with light-cured resin-modified glass ionomer cement (RMGIC) and conventional light-cured composite resin. In addition, the effects of acid etching and water contamination were examined. One hundred human premolars were randomly divided into five equal groups. The mini Dyna-lock upper premolar bracket was selected for testing. The first four groups were treated with light-cured RMGIC with or without 15 per cent phosphoric acid-etching treatment and with or without water contamination preceding bracket bonding. The control samples were treated with the conventional light-cured Transbond composite resin under acid etching and without water contamination. Subsequently, the brackets were debonded by tensile force using an Instron machine. The modified adhesive remnant index (ARI) scores were assigned to the bracket base of the debonded interfaces using a scanning electron microscope. The bond strength and modified ARI scores were determined and analysed statistically by one-way analysis of variance and chi-square test. Under all four conditions, the bond strength of the light-cure RMGIC was equal to or higher than that of the conventional composite resin. The highest bond strength was achieved when using RMGIC with acid etching but without water contamination. The modified ARI scores were 2 for Fuji Ortho LC and 3 for Transbond. No enamel detachment was found in any group. Fifteen per cent phosphoric acid etching without moistening the enamel of Fuji Ortho LC provided the more favourable bond strength. Enamel surfaces, with or without water contamination and with or without acid etching, had the same or a greater bond strength than Transbond.

Microleakage under Ceramic and Metallic Brackets Bonded with Resin-Modified Glass Ionomer

To test the null hypothesis that there is no significant difference between the microleakage of adhesive interferences at the occlusal and gingival margins of both ceramic and metallic brackets bonded with light-cured resin-modified glass ionomer and a conventional adhesive. Sixty freshly extracted human maxillary premolar teeth were randomly divided into four groups of 15 teeth each. Metal and ceramic brackets were bonded to groups 1 and 2 with resin-modified glass ionomer adhesive (RMGIA). Metal and ceramic brackets were bonded to group 3 and group 4 with a conventional adhesive (CA) system. A dye-penetration method was used for microleakage evaluation. Microleakage from the occlusal and gingival margins was determined by a stereomicroscope for the enamel-adhesive and bracket-adhesive interfaces. Statistical analysis was performed using the Kruskal-Wallis test and the Mann-Whitney U-test with a Bonferroni correction. The gingival side of all groups exhibited higher microleakage scores compared with the occlusal side for both adhesive interfaces. All bracket and adhesive combinations displayed statistically significant differences in microleakage between the enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival sides of the brackets (P < .001). When the adhesive systems were compared, the RMGIA showed more microleakage than the CA between the different interfaces. The hypothesis is rejected. RMGIA results in more microleakage between enamel-adhesive interfaces.

Polymerization Efficiency of Glass-Ionomer and Resin Adhesives under Molar Bands

To determine the degree of cure of a light-cured resin-modified glass ionomer (RMGI) under molar bands compared with a light-cured resin and a dual-cured resin. The 3 cements used were Fuji Ortho LC, Eagle Spectrum resin, and Variolink II dual-cure. Each sample was indirectly light cured for 20 seconds (10 seconds occlusally, 10 seconds cervically) under sections of molar bands, and the degree of cure was evaluated with micro-MIR FTIR spectroscopy. The RMGI exhibited a significantly higher mean degree of cure (55.31%) than both of the resins (Eagle 19.23%; Variolink II, 25.42%), which did not differ significantly at alpha = .05 level of significance. Higher degree of conversion can be obtained from RMGIs under molar bands compared with composite resin adhesives provided the proper curing technique is used.

ART and Conventional Root Restorations in Elders after 12 Months

Successful use of atraumatic restorative treatment (ART) in children has been reported, but little information is available regarding its use in older adults. The hypothesis of this study was that survival rates of root restorations placed by both ART and the conventional technique were similar. Root-surface caries lesions in 103 institutionalized elders in Hong Kong were treated randomly by either: (1) the conventional approach-caries removed by dental burs, and the cavity filled with light-cured resin-modified glass ionomer; or (2) the ART approach-caries removed by hand instruments, and the cavity filled with chemically cured high-strength glass ionomer. In total, 84 conventional and 78 ART restorations were placed. After 12 months, 63 conventional and 59 ART restorations were reviewed, and the respective 12-month survival rates were 91.7% and 87.0% (p > 0.05). It is concluded that the survival rates of both types of root restorations were high and similar.

Comparative assessment of light-cured resin-modified glass ionomer and composite resin adhesives: In vitro study of a new adhesive system

The ideal adhesive system is one that prevents decalcifications and has sufficient bond strength to withstand untimely impact forces on bonded brackets. The purpose of this investigation was to study and compare the bond strengths and adhesive remnant indexes of light-cured resin-modified glass ionomer and conventional resin adhesives. A new light-cured resin-modified glass ionomer adhesive was compared with the conventional adhesive systems. The effects of the new adhesive, with a system of etching and using adhesive promoters on the tooth enamel, as well as microetching the brackets, were analyzed. Comparisons were made (analysis of variance and the Tukey method) between this and other adhesive systems. The new adhesive system is indicated where prevention of decalcification and increased bond strength in noncompliant patients are indicated. (Am J Orthod Dentofacial Orthop 2001;119:256-62)

A twelve-month clinical trial comparing the bracket failure rates of light-cured resin-modified glass-ionomer adhesive and acid-etch chemical-cured composite

Abstract A clinical study was undertaken to compare the failure rate over a twelve-month period of orthodontic brackets bonded with a light-cured resin-modified glass-ionomer (Fuji Ortho LC-GC International Japan) and an acid-etch chemically-cured two-paste composite (Orthodontic Concise - 3M USA). Failure rates of 6.1 per cent and 5.4 per cent respectively were reported, with no statistically significant difference b etween the two adhesives. This finding, along with the relative ease of use and possible advantages of reduced risk of peribracket demineralisation, suggests that the resin-modified glass-ionomer adhesive may become more popular as a bracket adhesive.

Radiopacity of resin-modified glass ionomer liners and 2 bases

Statement of problem. Lining and base materials for restorations have traditionally been autopolymerized and include conventional glass ionomer cements. Light-cured resin-modified glass ionomer cements have recently become available, but a lack of information exists regarding their radiopacity. Purpose of study. In this study the radiopacity of glass ionomer cements was assessed with a standard method that related densitometric measurements to an equivalent thickness of aluminum. Material and methods. Radiographs were made of specimens with seven materials commonly used as liners and bases: two reinforced zinc oxide–eugenol cements (Kalzinol and Intermediate Restorative Material, De Trey Dentsply), a zinc phosphate cement (SS White, S.S. White Manufacturing), three resin-modified glass ionomer liners (Vitrebond [3M Dental Products], Fuji Lining LC [GC Dental], and Photac-Bond [ESPE Dental Medizin GmbH]), and a conventional glass ionomer liner/base (Ketac-Bond, ESPE Dental-Medizin GmbH), with dentin as a control. The radiopacity of all materials was compared with dentin. Results. Kalzinol had the greatest radiopacity of the materials tested. The glass ionomer cements were substantially less radiopaque than other materials. The conventional glass ionomer cement, Ketac-Bond, was more radiopaque than the three resin-modified glass ionomer cements. Of the three resin-modified glass ionomer materials, Vitrebond was the most radiopaque and Fuji Lining LC was the least radiopaque. Conclusion. Future resin-modified glass ionomer materials are recommended to be formulated to increase radiopacity for improved clinical detection. (J Prosthet Dent 1997;77:239-42.)

Effects of Uncontrolled Outdoor Storage on the Polymerization, Manipulation, and Appearance of Visible Light-Cured Composite Resin and Resin-Modified Glass Ionomer Materials

Four light-cured composite resins (Z100, Heliomolar RO, Herculite XRV, and Prisma APH) and two resin-modified glass ionomer restorative materials (Fuji II LC and VariGlas VLC) were placed in an uncooled, unheated outdoor storage shed for 12 months. Maximum and minimum ambient temperatures were recorded every 24 hours. Each month, samples were polymerized with a visible light source and alterations in polymerization were assessed using a scratch test. Problems with manipulation or changes in appearance were also monitored. Samples stored outdoors were compared to control samples maintained at room temperature [68-74 degrees F (20-23.3 degrees C)]. Results showed that polymerization of all materials tested was apparently unaffected to any significant clinical degree by outdoor storage at temperatures ranging from 20 to 112 degrees F (-6.6-44.4 degrees C) over 12 months. Eight months into the study, the VariGlas VLC liquid had separated into a viscous gel and watery component. None of the other remaining materials demonstrated any changes in manipulation or appearance. All materials tested except VariGlas VLC appear suitable for use during military deployment or field training exercises under similar environmental conditions.

Resin-modified glass ionomers for luting posterior ceramic restorations

Objectives. Until recently, esthetic inlay restorations in posterior teeth have been limited to cavities surrounded by enamel. Dentin adhesive systems in combination with luting composites and light-cured resin-modified glass ionomer cements offer a possibility for bonding ceramic inlays to cavities when the cervical margin is in dentin. This study was designed to compare in vitro marginal integrity of ceramic inlays bonded to dentin to restorations placed in cavities with margins located entirely in the enamel. Methods. In the present in vitro study, the sealing abilities of a dentin bonding agent/luting composite combination (Syntac/Dual Cement, Vivadent) and resin-modified glass ionomers (Photac Fil, Photac Bond, ESPE; Dyract, De Trey Dentsply; Fuji II LC, GC Dental Industrial Corp.; and Vitremer, 3M Dental Products) used as luting agents in cavities extending beyond the cemento-enamel junction, were compared to the sealing abilities of a conventional luting composite (Vita Cerec Duo Cement, Vita) in cavities within sound enamel. SEM analysis and dye penetration were performed to evaluate marginal integrity at the cervical cavity margins. Results. The dentin bonding agent/luting composite combination (Syntac/ Dual Cement) rendered a marginal seal within the dentin similar to the quality obtained with the conventional luting procedures within sound enamel. When three out of the five resin-modified glass ionomers were used as luting agents (Dyract, Fuji II LC and Vitremer), the results were comparable to those reported for the dentin bonding agents and the conventional method. Significance. Light-cured resin-modified glass ionomer cements may be considered as an alternative to dentin bonding agents when the cavity margins of ceramic inlay restorations are within the dentin. However, further studies, e.g., wear resistance, must be performed.