Glass Ionomer Cement Fillings Research Articles

Finite Element Analysis in Setting of Fillings of V-Shaped Tooth Defects Made with Glass-Ionomer Cement and Flowable Composite

The aim of the present paper is to investigate the deformation–stress state of fillings of V-shaped tooth defects by finite element analysis (FEA). Two different materials are used—auto-cured resin-reinforced glass-ionomer cement (GIC) and flowable photo-cured composite (FPC). Two materials are placed into the cavity in one portion, as before the application of the composite the cavity walls are covered with a thin adhesive layer. Deformations and equivalent von Mises stresses are evaluated by FEA. Experimental study of micro-leakage is performed. It is established that there is an analogous non-homogeneous distribution of equivalent Von Mises stresses at fillings of V-shaped defects, made with GIC and FPC. Maximum stresses are generated along the boundaries of the filling on the vestibular surface of the tooth and at the bottom of the filling itself. Values of equivalent Von Mises stresses of GIC fillings are higher than that of FPC. Magnitude and character of deformation distribution at GIC and FPC fillings are similar—deformation is maximum along the vestibular surface of the filling and is 0.056 and 0.053 mm, respectively. In FPC fillings, the adhesive layer, located along the cavity/filling boundary, is characterized with greatest strain. The experimental study of micro-leakage has confirmed the adequacy of models used in FEA.

Oral Health Status and Gingival Response to Three Different Restorative Materials among Saudi Patients: A Clinical & Histopathological Study

Background: The correlation between oral health and dental restoration is fundamental. For the gingival and periodontal tissues to stay healthy, dental restoration should be in regularity with the surrounding tissues. This study aims to assess the oral health status and histopathological gingival response to three different restorative materials among Saudi patients. Methods: The study groups consist of 240 patients (50% males and 50% females), aged 18 - 45, with inclusion and exclusion criteria in the study. Participants are divided into three equal groups: those with composite resin restorations, those with amalgam restorations and those with glass ionomer restorations. Biopsies were taken from adjacent gingival tissues. Clinical parameters were determined by: plaque index (PLI), gingival index (GI) and clinical attachment loss (CAL). All data were collected and evaluated by through statistical analysis. Results: The clinical findings of the current study revealed that amalgam restorations produce a higher means of PLI, GI and CAL compared with composite resin restorations and glass ionomer restorations, but not insignificant levels, except CAL (p = 0.004*). As for histopathological findings, there were significant differences in gingival tissue response to amalgam restorations, composite resin restorations and glass ionomer cement fillings, where there were statistically significant differences in numbers of chronic inflammatory cells (p < 0.001). Conclusion: At the end of the present study, we concluded that the amalgam restorations are less biocompatible compared to composite resin restorations and glass ionomer restorations.

Evaluation of a conventional glass ionomer cement with new zinc formulation: effect of coating, aging and storage agents

The study focused on a recently launched conventional glass ionomer cement (GIC) with a particular chemical formulation of both, filler and acrylic liquid, by analysing its mechanical behaviour in comparison to three conventional GICs. Furthermore, the effect of resin coating and storage conditions was evaluated. Three commercially available GICs were chosen: Riva Self Cure (SDI), Fuji IX Fast (GC) and Fuji IX GP Extra/Equia (GC). Additionally a newly developed zinc-containing GIC--ChemFil Rock (Dentsply)--was tested. Mechanical properties were determined at macro- [flexural strength (FS) and modulus of elasticity (E (flexural))] and micro-scale [Vickers hardness (VH) and indentation modulus (E)] after storing coated and uncoated specimens in artificial saliva and distilled water for 7 and 30 days. ChemFil Rock revealed the highest FS, but the lowest VH and E. The micro-mechanical properties of the analysed GICs did neither benefit from the new zinc formulation nor from resin coating. A resin coating is nevertheless a valuable support for GIC fillings, since it offers the absence of visible surface defects like crazing and voids, and thus, it led to significant improvements in flexural strength. This statement is also valid for ChemFil Rock, contrary to manufacture recommendation. The impact of storage agent and storage duration on the measured properties was low. The new development (ChemFil Rock) might represent a promising approach regarding longevity of GIC fillings in molar regions, due to the high flexural strength and the absence of visible surface defects like crazing and voids. All GICs should receive surface protection in order to perform their maximum in stability.

Hubungan Tumpatan Glass Ionomer Cement dan Pertumbuhan Streptococcus Mutans di Dalam Saliva

The study was a quasi experimental one, supported by microbiological data. The respondents had been purposively chosen from three Bekasi elementary schools in 2002, with 72 children as treatment group and 72 children as control group. Data collected included oral and laboratory examinations. Dental health status of permanent dentition was determined using the DMF-T index. The data was collected at the start and 120 days after intervention. Data analysis was by paired t-test for before and after treatment, and by independent t-test for comparating treatment and control. For the average the means 2 samples t-test difference was used, and for the average difference between the same groups the mean one sample t-test was applied. For the nominal scale proportion difference the likelihood ratio test was applied, and for the ordinal scal the nonparametric one-way Anova was used. Simple regression test was used to determine the relation between dependent and independent variables. The results of the study show decrease of S. mutans colonies in saliva after treatment (p= 0,001) and decreasing DMF-T score for treatment group. In control group, there is no decrease in S. mutans colonies, but increasing DMF-T score was found. The conclusion was that glass ionomer cement fillings can inhibit S. mutans growth in saliva.

Fluoride release and uptake by glass-ionomers and related materials and its clinical effect

The anticariogenic effect of silicate cement is well known and considered a result of fluoride release. In several studies a similar fluoride release from conventional glass-ionomer cement (GIC) has been established. Therefore, an anticariogenic effect may be predicted from the GICs too. In my studies the fluoride release was studied by exposing the test specimens to a continuous flow of running tap water. At certain time periods the specimens were transferred for 1 week in a small amount of deionized water (5 ml). The determination of the fluoride content of the solution showed the fluoride release of the material at that time. There was an initial ‘burst’ effect of fluoride release and then the release gradually decreased, settling at a constant level. The long-term release from conventional GICs was shown to remain on the same level for at least 8 years. The amount of the constant release did not differ much between different brands. Resin-modified GICs released fluoride to the same extent and in the similar way as conventional GICs whereas polyacid-modified composites (‘compomers’) did not show an initial fluoride ‘burst’ effect. To study the fluoride binding ability of GICs, specimens which had been exposed to running water for different periods of time were treated with a 50 ppm fluoride solution. After this ‘recharging’ GIC and resin-modified GIC specimens released more than twice the amount of fluoride released before the treatment. The fluoride treatment had no effect on polyacid-modified composites or on fluoride-containing composites or on the amalgams. To get an impression of the clinical effect of GICs a questionnaire was handed out to practitioners attending courses in the Nordic countries and in Australia during the period 1991–1992 which resulted in 954 answers. Among other questions, the dentists were asked if they had observed caries and gingival inflammation in association with GIC and composite fillings. According to the opinion of most dentists caries and gingival inflammation had never or only seldom been observed in association with GIC fillings whereas most dentists had observed these complications often in connection with composite restorations.

Hypermineralization of Dentinal Lesions Adjacent to Glass-ionomer Cement Restorations

Previous reports have shown a release of fluoride from glass-ionomer cement (GIC) restorations into the oral fluids. Fluoride in the ambient fluids has a caries-preventive effect by enhancing remineralization and inhibiting demineralization of the dental hard tissues. Therefore, the current investigation was undertaken to determine whether GIC fillings could contribute to the remineralization of caries lesions in dentin. Small circular preparations were made in disks of dentin which had incipient caries-like lesions in the remaining tissue. The preparations were filled with amalgam or composite materials (as controls) or with GIC. The specimens thus contained a restoration close to a dentinal caries-like lesion. The specimens were placed contralaterally in the buccal surfaces of removable partial dentures and were worn intra-orally by volunteers for a 12-week experimental period, after which the specimens were sectioned and analyzed by microradiography. All specimens with GIC restorations exhibited hypermineralization in the tissue bordering the filling and in the wall of the preparation which had been in contact with the restoration. The (caries-like) lesions were remineralized, even under conditions of heavy plaque formation. In contrast, specimens with amalgam or composite restorations showed further extensive demineralization. This study demonstrates a significant remineralization potential exerted by the fluoride-releasing GIC restorative material. Consequently, the choice of the restorative material might be crucial for the occurrence or prevention of recurrent caries around restorations.

Fluoride Concentration, Mutans Streptococci and Lactobacilli in Plaque from Old Glass lonomer Fillings

Previous studies have found that the fluoride concentration of plaque growing on or adjacent to glass ionomer cement (GIC) is increased and the proportion of mutans streptococci in plaque is reduced. So far, there are only a few studies of the long-term effect of glass ionomer fillings on plaque in vivo. The aim of this study was to determine whether old GIC fillings have effects on plaque fluoride and microflora and whether this effect can be increased by topical application of fluoride on GIC fillings in vivo. The participants were 27 adults with at least 3 GIC fillings about 3 years old. Plaque was collected from sites adjacent to the GIC fillings and from the contralateral teeth, after which a 1.2% fluoride gel was applied to all teeth. Three days later, plaque was collected from the same sites as before. Stimulated saliva was also collected at both appointments. The results show that none of the patients had elevated levels of fluoride in their saliva either before or 3 days after the fluoride treatment. The fluoride concentration was 0.51 microgram/mg protein in plaque on GICs and 0.35 microgram/mg protein in plaque on contralateral teeth (p = 0.028). After the fluoride treatment, the respective fluoride concentrations were 0.59 microgram/mg and 0.75 microgram/mg (p = 0.849). No significant differences in the proportion of mutans streptococci and lactobacilli in plaque from GIC and contralateral teeth were found. The results suggest that the fluoride concentration of plaque growing on old GIC fillings is slightly increased. In this study, however, this had no significant effect on the cariogenic microflora.(ABSTRACT TRUNCATED AT 250 WORDS)