Conventional Glass Ionomer Restorations Research Articles

Effect of various surface coating methods on surface roughness, micromorphological analysis and fluoride release from contemporary glass ionomer restorations.

To evaluate the effect of various surface coating methods on surface roughness, micromorphological analysis and fluoride release from contemporary resin-modified and conventional glass ionomer restorations. A total of 72 permanent human molars were used in this study. The teeth were randomly assigned into 2 groups according to type of restorative materials used; resin modified glass ionomer cement and conventional glass ionomer (SDI Limited. Bayswater Victoria, Australia). Each group was subdivided into 3 subgroups according to the application of coat material; Sub-group1: without application of coat; Sub-group2: manufacturer recommended coat was applied and sub-group3: customized (vaseline) coat was applied. Each group was then subdivided into two divisions according to the time of testing; immediate (after 24h) and delayed (after 6 months of storage). Three specimens from each sub-group were selected for surface roughness test (AFM) and another 3 specimens for the micromorphological analysis using scanning electron microscope (SEM). For the fluoride release test, a total of 60 cylindrical discs were used (n = 60). The discs were randomly split into 2 groups according to type of restorative materials used (n = 30); resin modified glass ionomer cement and conventional glass ionomer. Each group was subdivided into 3 subgroups (n = 10) according to the application of the coat material; Sub-group1: without application of coat; Sub-group2: with the manufacturer recommended coat and sub-group3: with application of customized (vaseline) coat. Data for each test was then collected, tabulated, were collected, tabulated, and tested for the normality with Shapiro-Wilk test. Based on the outcome of normality test, the significant effects of variables were assessed using appropriate statistical analysis testing methods. Regarding the data obtained from surface roughness test, Shapiro-Wilk test showed normal distribution pattern of all values (p > 0.05). Accordingly, Two-way ANOVA outcome showed that the 'type of restoration' or 'test time' had statistically significant effect on the AFM test (p < 0.05). Regarding Fluoride specific ion electrode test 2-way ANOVA followed by Least Significant Difference (LSD) Post-hoc test revealed significant difference among the groups (p < 0.05). It showed that SDI GIC group after 14 days of measurement had the highest mean of fluoride release (36.38 ± 3.16 PPM) and SDI RMGIC after 30 days of measurement had the second highest mean of fluoride release (43.28 ± 1.89 PPM). Finally, regarding the micromorphological analysis using SEM, a slight difference was observed between the studied groups. Based on the results of this study, various coatings enhance surface roughness in the initial 24h of restoration insertion. Different coat types seems that have no influence on fluoride release and the micromorphological features of the restoration/dentin interface.

Comparative Evaluation of Fluoride Release from Four Commercially Available Pediatric Dental Restorative Materials.

The aim of this study was to evaluate the fluoride-releasing abilities of commercially available restorative materials such as-Activa™ BioActive-restorative™ material, Zirconomer (Shofu Inc), Beautifil® II (Shofu Inc), GC Gold Label 9 high strength posterior restorative glass ionomer cement (GIC Corp). A total of 40 disk specimens (10 of each material) were placed into distilled/deionized (DI) water and the fluoride release was measured for 30 days. Fluoride ion measurement was performed at the end of the 1st, 3rd, 7th, 15th, and 30th day under normal atmospheric conditions by fluoride ion selective electrode (F-ISE) (Orion 9609 BNWP, Ionplus SureFlow fluoride electrode, Thermo Scientific, United States of America) coupled to a benchtop analyzer (Hachsen Ion+). All the materials included in the study exhibited fluoride release. Although there were differences in the amounts of fluoride released between Activa™, Zirconomer, and GC Gold Label 9 the mean difference between these three groups was not found to be statistically significant. Beautifil® II showed low amounts of fluoride released at all time intervals. Among the above-compared materials Activa™ and Zirconomer exhibit both improved mechanical properties as well as they have fluoride-releasing ability so can be preferred over conventional glass ionomer restorations. Dhumal RS, Chauhan RS, Patil V, et al. Comparative Evaluation of Fluoride Release from Four Commercially Available Pediatric Dental Restorative Materials. Int J Clin Pediatr Dent 2023;16(S-1):S6-S12.

Effects of bioactive additions on the physical properties of glass polyalkenoate cement

Aim Conventional glass ionomer cements are clinically attractive materials and have unique properties that make them useful dental restorative materials. The glass ionomer cements however are slightly brittle materials though they deform a little under load. They display high compressive strengths but slightly weak flexural strengths. Collagen type I and RGD peptides (Arg-Gly-Asp) are the most effective and widely used bioactive molecules to promote cell adhesion on a synthetic surface. This study investigates the effect of chairside addition of bioactive molecules (Collagen type I and RGD) into glass polyalkenoate cement on improving the physical properties. Materials and methods Mechanical properties of the glass polyalkenoate cement (ChemFil Superior, Dentsply De Trey, Konstanz, Germany) were investigated both at baseline and after incorporating bioactive additions made at the time of mixing the material. The properties that are of potential significance for clinical durability were determined namely; compressive strength, diametral compressive strength, three-point flexural strength, diametral compressive fatigue limit, and biaxial flexural strength. Results: Additions of Type I Collagen and RGD to ChemFil Superior improved all physical properties measured except shear bond strength where no detriment was observed. Conclusion Chairside additions of bioactive molecules to conventional glass ionomer restorations have potential clinical applications and represent a new paradigm in dentistry that can be utilized to improve biocompatibility, mechanical properties, and therefore, clinical durability. Improving the mechanical strength of glass ionomer restorations by optimized reinforcement strategy requires further investigation. Clinical significance: the methodology of mixing conventional glass ionomer with bioactive molecules for superior biocompatibility and reinforcement, developed in the present study, should be applicable to chairside dental procedures. The increase in physical properties of the glass polyalkenoate, achieved in the present study, may help extend its dental applications to the restoration of stress-bearing cavities.

Longevity of posterior restorations in primary teeth: Results from a paediatric dental clinic

ObjectivesThe aim of this retrospective study was to evaluate the longevity of restorations in the posterior primary teeth of children attending to a public paediatric dental clinic and to test the factors associated with failures. MethodsPatient records of 329 children (162 boys and 166 girls) were used for collecting and analyzing data. A total of 565 restorations in primary teeth were included in the study. All children enrolled in the study were classified as high caries risk. The longevity of restorations from their placement until failure (up to 4 years of follow-up) was assessed using the Kaplan–Meier survival curves with log-rank test. Multivariate Cox regression analysis with shared frailty (p<0.05) was used to assess the factors associated with failures. ResultsUp to 4 years of follow-up, the annual failure rates were 9.5% for composite fillings, 12.2% for light-cured glass ionomer restorations, and 12.9% for conventional glass ionomer restorations with statistical difference between the materials (p=0.014). Glass ionomer restorations had a higher risk of failure over time compared with composites (HR 1.86, 95% CI 1.17–2.97). In crude analysis, Class II restorations showed lower survival rate than Class I restorations (p=0.031) but lost significance after adjustments. ConclusionsOur findings suggested that the material influenced the survival rate of primary posterior restorations, with composite presenting the best performance. Clinical significanceDifferences were observed between restorative materials with different properties in primary teeth up to 4 years of follow-up. This study provides valuable information regarding the primary teeth posterior restoration longevity in a paediatric population with restorations performed under daily life clinical environment.

Resin-Modified Glass Ionomer Restorations may have Better Long-term Outcomes than Conventional Glass Ionomer Restorations in Primary Teeth

Resin-modified and conventional glass ionomer restorations in primary teeth: 8-year results. Qvist et al. J Dent 2004;32(4):285-94 . Ib The authors compared the longevity and cariostatic effects of resin-modified and conventional glass ionomer restorations in primary teeth. Governmental grants and industry (ESPE). Randomized controlled trial

Eight‐year study on conventional glass ionomer and amalgam restorations in primary teeth

The aim of this randomized clinical study was to compare the longevity and the cariostatic effects of conventional glass ionomer and amalgam restorations in primary teeth placed in everyday practice in the Danish Public Dental Health Service. All restorations inserted during a 7‐month period by 14 clinicians in 2 municipalities were included in the study. The sample consisted of 515 conventional glass ionomer restorations and 543 amalgam restorations in 666 children aged between 2.8 and 13.5 years. The restorations were in contact with 592 unrestored surfaces in primary and permanent teeth. The study was terminated after 8 years, with 2% of the restorations in function and 7% patient dropouts. Fifty percent of the teeth restored with glass ionomer and 63% of those with amalgam were exfoliated with the restoration in situ, while 42% of the glass ionomer and 20% of the amalgam restorations had been repaired or replaced. Fracture of restoration, endodontic complication, and loss of retention were the major reasons for failure. The 50% survival time for glass ionomer restorations in all cavity types was 42 months, while the median survival time for amalgam restorations could not be estimated but exceeded 7.8 years (P<0.001). Progression of caries lesions on tooth surfaces adjacent to amalgam restorations required operative treatment on 30% of the teeth, while only on 16% of teeth adjacent to glass ionomer restorations. The 75% survival time was 40 months for surfaces in contact with glass ionomer compared to 25 months for surfaces in contact with amalgam (P=0.005). Multivariate analyses were performed in order to assess the influence of a number of factors on the longevity of restorations, occurrence of prevalent failures, and caries treatment of surfaces in contact with the restorations. Owing to the high frequency of failures of the conventional glass ionomer restorations, it was concluded that they are not an appropriate, universal alternative to amalgam for restorations in primary teeth, although they reduce caries progression and the need for operative treatment of adjacent surfaces.

Age of restorations at replacement in permanent teeth in general dental practice

The ages of 6,761 restorations replaced in permanent teeth, 6,088 in adults ≥19 years of age and 673 in adolescents ≤18 years, were available for analyses. The results showed that the median age of amalgam restorations in adults was 11 years and that of resin-based composite restorations 8 years. This difference in longevity was significant (P = 0.0001). The median age of failed conventional glass ionomer restorations in adults was 4 years and for resin-modified glass ionomer 2 years. In adolescents, the median longevity of failed amalgam restorations was 5 years and that of composite restorations 3 years, while both types of glass ionomers had a median longevity of 2 years. The data were subdivided based on clinician gender and practice setting. The results showed that the median age of amalgam and composite restorations replaced by male clinicians was higher than that for female clinicians irrespective of clinical setting. The median age of amalgam and composite restorations replaced by salaried dentists was significantly lower than that by private practitioners. Minor differences were noted in longevity of restorations between male and female patients. The age of replaced restorations was shortest for the group of clinicians with the least clinical experience and highest for those that graduated ≥ 30 years ago.Keywords: Amalgam composite; gender differences; glass; ionomer; practice setting

In vitro Caries-inhibitory Properties of a Silver Cermet

Recurrent caries is one of the primary causes of failure of dental restorations. One method for reducing the frequency and severity of this problem is the use of fluoride-releasing restorative materials. The glass-ionomer cements are a type of fluoride-releasing material. They have been used extensively in recent years for a variety of clinical applications. However, in comparison with other restorative materials such as amalgam and composite resins, glass ionomers have relatively poor physical properties. Sintering of silver particles to glass-ionomer powder is a means of improving these physical properties. The sintered material is called a silver-glass ionomer or silver cermet. This study examined the in vitro caries-inhibitory potential of a silver cement by means of two methods. First, long-term fluoride release was measured. Second, an artificial caries system was used for evaluation of caries inhibition by cerment restorations in extracted teeth. In comparison with a standard glass-ionomer restorative material, fluoride release from the cermet material was significantly less throughout a 12-month period. The results from the artificial caries system indicated that this decreased fluoride release corresponded with a lesser degree of caries inhibition. Lesions around cermet restorations in both enamel and root surfaces were significantly more severe than those around conventional glass-ionomer restorations. However, in comparison with amalgam and composite resin restorations, the cermet did have some cariostatic activity.