A Comparative Evaluation of Mechanical Properties of Four Different Restorative Materials: An In Vitro Study

Tensile strength of conventional glass ionomer cement and silver reinforced glass ionomer cement

A comparative analysis and assessment of the compressive strength (CS) and diametral tensile strength (DTS) between conventional glass ionomer cement (C-GIC) and a silver-reinforced GIC (S-GIC) variant is of interest. Ten specimens of both C-GIC (GC Fuji II, Japan) and S-GIC (Riva Silver, SDI, Australia) were fabricated for the evaluation of compressive strength, and an identical number of samples were created for the examination of tensile strength. These specimens were then tested using a universal testing apparatus. The results exhibited that both the compressive and diametral tensile strengths were significantly greater for the S-GIC cement in comparison to the C-GIC, with a notable p-value of 0.001. The findings suggest that S-GIC may be considered a viable alternative to conventional GIC.

A comparative evaluation of fluoride release and rechargeability in conventional GIC (type II), pediatric GIC (type IX), and Cention-N: an in vitro study

PURPOSE

A comparative evaluation of fluoride release and re-chargeability in conventional glass ionomer cement (GIC) (type II), Pediatric GIC (type IX), and Cention-N-an in vitro study at an interval of first, fourteenth, and twenty first days.

METHODS

Three groups of test materials, each with twenty samples, were prepared. Measurements of the cumulative fluoride release [parts per million (ppm)] and re-release measured on the first, fourteenth, and twenty first days. Analysis of variance (ANOVA) was used to compare the means for different readings, and Tukey's post hoc analysis was used to compare each group with each other.

RESULTS

Initial and subsequent fluoride release of Cention-N at days one, fourteen, and twenty-one were all noticeably higher than those of conventional and pediatric GIC.

CONCLUSION

Compared to the Conventional and Pediatric GIC restorative materials, Cention-N was more effective in the initial and fluoride re-release.

In vitro characterization of a novel resin-based restorative material containing alkaline fillers

OBJECTIVE

In this study, a comparative evaluation of the physicochemical properties of Cention N and other direct restorative materials was performed. Three restorative materials-a resin-modified glass ionomer (Fuji II LC), an alkasite-based resinous material (Cention N), and a resin composite (Tetric N Ceram)-were characterized in terms of degree of conversion, Knoop hardness number (KHN) ratio, flexural strength, elastic modulus, water sorption, water solubility, microshear bond strength to dentin, immediate microleakage, and radiopacity.

METHODOLOGY

The microshear bond strength to dentin and microleakage of Cention N were evaluated with and without the application of an adhesive system (Tetric N Bond Universal). A one-way ANOVA test was used to analyze the data in terms of degree of conversion, KHN ratio, water sorption, water solubility, microshear bond strength to dentin, and radiopacity. A two-way ANOVA test (carried out considering the material type and ethanol aging as factors) was used to analyze the data in terms of flexural strength and elastic modulus. The Kruskal-Wallis test was used to statistically analyze the data on microleakage. A significance level of α=0.05 was used for all tests.

RESULTS

Fuji II LC was found to have the highest degree of conversion, water sorption, and microleakage, as well as the lowest flexural strength. Cention N had the highest solubility; when used with an adhesive system, it achieved bond strength and microleakage similar to those of the Tetric N Ceram composite. Tetric N Ceram had the highest degree of conversion, KHN ratio, and radiopacity. Conclusion: The properties of Cention N validate its efficacy as an alternative direct restorative material when used in conjunction with an adhesive system.

In Vitro Comparison of Surface Roughness, Flexural, and Microtensile Strength of Various Glass-Ionomer-Based Materials and a New Alkasite Restorative Material

This study aims to evaluate the physical properties of Cention N and various glass-ionomer-based materials in vitro. The groups were obtained as follows: Group 1 (LC-Cent): light-cured Cention N; Group 2 (SC-Cent): self-cured Cention N; Group 3 (COMP): composite (3M Universal Restorative 200); Group 4 (DYRA): compomer (Dyract XP); Group 5 (LINER): Glass Liner; Group 6 (FUJI): FujiII LC Capsule; and Group 7 (NOVA): Nova Glass LC. For the microtensile bond strength (μTBS) test, 21 extracted human molar teeth were used. The enamel of the teeth was removed, and flat dentin surfaces were obtained. Materials were applied up to 3 mm, and sticks were obtained from the teeth. Additionally, specimens were prepared, and their flexural strength and surface roughness (Ra) were evaluated. Herein, data were recorded using SPSS 22.0, and the flexural strength, μTBS, and Ra were statistically analyzed. According to the surface roughness tests, the highest Ra values were observed in Group 6 (FUJI) (0.33 ± 0.1), whereas the lowest Ra values were observed in Group 2 (SC-Cent) (0.17 ± 0.04) (p < 0.05). The flexural strengths of the materials were compared, and the highest value was obtained in Group 2 (SC-Cent) (86.32 ± 15.37), whereas the lowest value was obtained in Group 5 (LINER) (41.75 ± 10.05) (p < 0.05). When the μTBS of materials to teeth was evaluated, the highest μTBS was observed in Group 3 (COMP) (16.50 ± 7.73) and Group 4 (DYRA) (16.36 ± 4.64), whereas the lowest μTBS was found in Group 7 (NOVA) (9.88 ± 1.87) (p < 0.05). According to the μTBS results of materials-to-materials bonding, both Group 2 (SC-Cent) and Group 1 (LC-Cent) made the best bonding with Group 3 (COMP) (p < 0.05). It can be concluded that self-cured Cention N had the highest flexural strength and lowest surface roughness of the seven materials tested. Although the bond strength was statistically lower than conventional composites and compomers, it was similar to resin-modified glass ionomer cements. Additionally, the best material-to-material bonding was found between self-cured Cention N and conventional composites.

A comparative evaluation of fracture toughness, flexural strength, and acid buffer capability of a bulk-fill alkasite with high-strength glass-ionomer cement: An in vitro study

BACKGROUND

Although glass-ionomer cement (GIC) has many unique properties and advantages, it still lacks favorable mechanical properties. Cention N is a recent alkasite material with excellent mechanical properties. The purpose of this study was to compare the mechanical properties (fracture toughness [FT] and flexural strength [FS]) and acid buffer capability of an alkasite material to GIC.

MATERIALS AND METHODS

In this in vitro study, a total of 60 samples were prepared using Cention N or GIC. Twenty specimens (n = 10) were prepared using beam-shaped Teflon molds for FS, and twenty specimens (n = 10) were prepared with a similar mold with a notch for FT. These were evaluated on a universal testing machine using a three-point bend test. Twenty (n = 10) disk-shaped specimens were prepared for acid buffer capability. The samples were stored in distilled water for a week. This was followed by immersion in lactic acid with a pH of 4 for calculation of the materials acid buffering capacity at 30 and 60 min from exposure using a pH meter. The data obtained were tabulated and subjected to Kolmogorov-Smirnov test and Shapiro-Wilk test to assess the normal distribution and further analyzed using the Student's t-test to assess the level of significance, P < 0.05 was considered statistically significant.

RESULTS

The mean FT, FS, and acid buffer capability of Cention N were significantly higher than GIC at P < 0.05.

CONCLUSION

The present study surmised that Cention N exhibited higher FT, FS, and acid buffer capability than GIC.

An In Vivo Evaluation of Retention and Antibacterial Efficacy of Posterior High Strength Glass Ionomer Cement and Glass Hybrid Bulk-fill Alkasite Restorative Material as Conservative Adhesive Restoration in Children with Mixed Dentition: A Comparative Study

Aim

The aim of the study was to compare and evaluate the retention and antibacterial efficacy of posterior high strength glass ionomer cement and glass hybrid bulk-fill alkasite restorative material as a conservative adhesive restoration in children with mixed dentition.

Materials and methods

A total of 60 children of age 6-12 years with mixed dentition were selected and divided into group I (control group n = 30): posterior high strength glass ionomer cement and group II (experimental group n = 30): glass hybrid bulk-fill alkasite restorative material. Restorative treatment was carried out using these two materials. Retention of the material and salivary Streptococcus mutans and Lactobacillus species count was estimated at baseline, 1, 3, and 6 months. The collected data were statistically analyzed using International Business Machines (IBM) Statistical Package for the Social Sciences (SPSS) software (version 20.0 Chicago, Illinois, USA).

Results

About 100% retention of glass hybrid bulk-fill alkasite restorative material, and 90% retention of posterior high strength glass ionomer cement was observed according to United State Public Health Criteria. The * signifies statistically significant results, i.e. p < 0.0001 reduction in salivary S. mutans colony count and Lactobacillus species colony count was seen in both groups at different time intervals.

Conclusion

Both the materials showed good antibacterial properties, but glass hybrid bulk-fill alkasite restorative showed better retention, that is, 100% when compared to posterior high strength glass ionomer cement, which showed 90% retention at the end of 6 months follow-up.

How to cite this article

Soneta SP, Hugar SM, Hallikerimath S, et al. An In Vivo Evaluation of Retention and Antibacterial Efficacy of Posterior High Strength Glass Ionomer Cement and Glass Hybrid Bulk-fill Alkasite Restorative Material as Conservative Adhesive Restoration in Children with Mixed Dentition: A Comparative Study. Int J Clin Pediatr Dent 2022;15(5):529-534.

Strategies of Bioceramics, Bioactive Glasses in Endodontics: Future Perspectives of Restorative Dentistry

Prevalently, there is a primary strategy to cure caries using restorative materials notably bioceramics. Existing synthetic materials stimulate natural tooth structure with acceptable interfacial bonding and esthetic and biomechanical qualities with better durability. Several bioceramics have been introduced and investigated for their potentialities as restorative materials. Biomineralization of tooth initiates repair and regeneration of natural dental tissue and reinstating the integrity of periodontium. In the evolution of bioceramics in the aspects of different essential composition for dental application, recent technology and modern strategies revolutionize the restorative dentistry. Bioglass is one among the important bioceramics as a restorative material, and by regulating the properties of the material, it is possible to construct improved formulation towards restoration. This article reviews the current revolution of endodontics, existing restorative materials, and technologies to be achieve for engineering materials with the better design.

Comparison of physical and mechanical properties of three different restorative materials in primary teeth: an in vitro study

OBJECTIVE

Physical and mechanical properties of three different (Ketac Molar Easymix, Dyract XP, Cention N (CN)) restoratives with different ingredients were evaluated.

MATERIALS AND METHODS

Four groups were obtained; Group 1: CN LightCure, Group 2: CN SelfCure, Group 3: Ketac Molar Easymix and Group 4: Dyract XP. Disk-shaped samples (n = 10) were prepared and evaluated for the surface roughness test using a profilometer. For the flexure strength test, 2 × 2 × 25 mm bar-shaped samples (n = 10) were prepared, and a three-point bending test was applied to the samples. After preparing cavities for microleakage tests, teeth were restored with restoratives, immersed in dye, and microleakage was assessed. For the microtensile bond strength (µTBS) test, ten sticks were obtained for each group and were stressed under tension.

RESULTS

According to surface roughness tests, CN SelfCure showed the lowest value (0.13 μm), while Ketac Molar Easymix showed the highest value (0.28 μm), and significant differences were found between the groups. In flexural strength tests, the highest values were seen in CN SelfCure (82.94 MPa), with statistically significant differences between the groups. When CN SelfCure was applied with an adhesive, the teeth showed statistically decreased leakage than other groups on the gingival side. Higher leakage values were seen on the gingival side than the occlusal side in most groups, and the SelfCure groups showed decreased leakage than the LightCure groups. According to µTBS tests, the highest value was obtained in CN SelfCure-Adhesive group, while the lowest was in CN LightCure-Non-adhesive group. When µTBS was evaluated regardless of adhesive use, the SelfCure groups showed higher µTBS values than the LightCure groups. As a result of the µTBS and microleakage test, the difference between the use of CN with and without adhesive, regardless of the polymerization type, was found to be significant (p  < 0.05).

CONCLUSION

Cention N showed better properties in SelfCure mode, compared to the rest materials tested, but further in vitro and in vivo studies are needed to investigate the effect of different polymerization modes and the oral environmental conditions.

Comparative Evaluation of Adhesive Bond Strength of Conventional GIC and Cention N to Enamel and Dentin of Primary Teeth: An In Vitro Study

Aim

The aim of this in vitro study was to evaluate and compare the adhesive bond strength of conventional glass ionomer cement (GIC) and Cention N to the primary enamel and dentin using an accelerated fatigue test.

Materials and methods

A total of 30 sound human primary molars were collected and were mounted on a metal cylindrical block using acrylic resin, embedding the root up to cemento-enamel junction (CEJ). Proximal box was prepared on both mesial and distal surfaces, one of the cavity was restored with GIC (Type 9) and the other proximal cavity with Cention N. A nonretentive cavity design was followed for both the materials so as to maintain the uniformity between the two specimens were then placed under a universal testing machine (Instron) and subjected to accelerated cyclic loads till a separation fracture occurs at the tooth-restoration interface. The number of endured cycles a particular restoration could withstand before getting fractured was registered.

Results

Cention N resisted significantly more number of endured cycles before separation from the cavity as compared to GIC (p < 0.001).

Conclusion

Within the limitations of the study, it can be concluded that newly developed material Cention N is preferred alternative over conventional GIC for the restoration of proximal cavities in primary molars.

How to cite this article

Dhull KS, Dutta B, Pattnaik S, et al. Comparative Evaluation of Adhesive Bond Strength of Conventional GIC and Cention N to Enamel and Dentin of Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(4):412-416.

Flexural Properties of Bioactive Restoratives in Cariogenic Environments

This study determined the mechanical performance of bioactive restoratives in cariogenic environments and compared the flexural properties of various bioactive materials. The materials evaluated included a conventional resin-based composite (Filtek Z350 [FZ]) and 3 bioactive restoratives, namely an alkasite (Cention N [CN]), a giomer (Beautifil-bulk Restorative [BB]), and an enhanced resin-modified glass ionomer (Activa Bioactive Restorative [AV]). Beam-shaped specimens (12 x 2 x 2 mm) were produced, randomly allocated to 4 groups (n=10), and conditioned in deionized solution, remineralizing solution, demineralizing solution (DE), or pH cycled for 14 days at 37°C. After conditioning/pH cycling, the specimens were subjected to 3-point flexural testing. Flexural data were subjected to statistical analysis using analysis of variance or Tukey's test (α=0.05). Mean flexural modulus and strength ranged from 3.54 ± 0.33 to 7.44 ± 0.28 GPa, and 87.07 ± 8.99 to 123.54 ± 12.37 MPa, respectively. While the flexural modulus of the bioactive restoratives was not affected by cariogenic/acidic conditions, flexural strength usually decreased, with the exception of CN. The strength of BB was significantly reduced by DE and pH cycling, while that of AV was lowered by DE. For all conditioning mediums, AV had a significantly lower modulus than the other materials. Apart from conditioning in DE, where differences in flexural strength was insignificant, FZ and AV were generally significantly stronger than BB and CN. The effect of cariogenic environments on flexural strength was found to be material dependent, and aside from the alkasite material (CN), cariogenic conditions were observed to significantly decrease the strength of bioactive restoratives.

Comprehensive characterisation of flexural mechanical properties and a new classification for porosity of 11 contemporary ion-leaching dental restorative materials

The objectives of this study were to evaluate 4 aspects of ion-leaching restorative materials (ILMs): 4-point bending flexural strength (4 PB-FS) and relative mechanical properties; biaxial flexural strength (B-FS) in relation to 4 PB-FS; porosity; and surface morphology. Eleven ILMs were used for the 4-point bending test. Bar-shaped (n = 15) samples were fabricated, stored in distilled water for 7 days. Then 4 PB-FS and the other mechanical properties were determined. Five ILMs were selected for the B-FS test using disk specimens (n = 15). The correlation between 4 PB-FS and B-FS was addressed. After the 4 PB test, 5 randomised fragments from each material were used to make 0.5 mm-thick sections for light microscopy to investigate the degree of porosity using reflected and transmitted lights. Eight ILMs were selected for quantitative analysis of the fractional % pore volume (PV%) due to their relative pore prominence using ImageJ software. One-way ANOVA/Dunnett's T3 was used to test for significance. Resin-based ILMs (RB-ILMs) were ranked first (p < 0.05) for 4 PB-FS values (53.3-110.2 MPa) followed by resin-modified glass-ionomer cements (RMGICs; 30.9-44.3 MPa) and high-viscosity glass-ionomer cements (HVGICs; 12.9-19.6 MPa), respectively. 'Flexural modulus' (4 PB-E) and 'flexural toughness' (4 PB-T) of ILMs varied even though similar 4 PB-FS values were observed. There was a positive correlation (p < 0.001) between 4PB-FS and B-FS (R² = 0.992) with B-FS>4 PB-FS. There was no correlation between PV% and 4 PB-FS. In summary, material type played a major role in 4 PB-FS outcomes, whereas PV% seemed to have a minor effect when evaluating each material group of ILMs. Brittleness/ductility of ILMs was observed when determining 4 PB-E and 4 PB-T relative to 4 PB-FS. When selecting materials for posterior load-bearing dental restorations in high-caries risk patients, RB-ILMs or RMGICs would be more appropriate due to their superior flexural properties compared with recently introduced HVGICs. The decision for each situation will also be dependent on further evidence of the ion-leaching capacity.