A Comparative Evaluation of Dissolution Rate of Three Different Posterior Restorative Materials used in Pediatric Dentistry: An In Vitro Study

Aim

The study aimed to compare and assess the dissolution rate, color stability, and other mechanical parameters, such as compressive and flexural strength, of three distinct posterior restorative materials used in pediatric dentistry.

Materials and methods

The three posterior restorative materials used in pediatric dentistry are divided into group I-Zirconomer, group II-Composite, and group III-Cention N. Around 111 cylindrical specimens were grouped into three groups of 37 each. According to the manufacturer's standards, all materials were proportioned and handled. The materials were thermocycler in a chewing simulator and were subjected to various tests to estimate the dissolution rate, compressive strength, flexural strength, and color stability of the three individual groups.

Results

The dissolution rate was highest in Zirconomer, followed by Cention N and Composite, which were highly significant (p = 0.05). Compressive strength was highest with Cention N, followed by Composite and Zirconomer, which was highly important (p = 0.05). Cention N had the greatest flexural strength, followed by Composite and Zirconomer, which were highly significant (p = 0.05). Finally, the Composite had the highest color stability, followed by Cention N and Zirconomer among the three groups.

Conclusion

It is concluded that resin-based restorative materials outperform glass ionomer-based Zirconomer cement in terms of dissolution rate, compressive strength, flexural strength, and color stability.

Clinical significance

Because of the widespread improvement in dental materials, many dental restorative types of cement have emerged on the market. The features of good restorative materials are mechanical strength, fluid dissolution rate, and retention.

How to cite this article

Raman V, Srinivasan D, AR SE, et al. A Comparative Evaluation of Dissolution Rate of Three Different Posterior Restorative Materials used in Pediatric Dentistry: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-1):S20-S26.

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.

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.

Comparative Evaluation of Compressive Strength and Flexural Strength of Self-cured Cention N with Dual-cured Cention N: An In Vitro Study

Aim and objective

This study aimed to investigate and compare compressive strength and flexural strength of self-cured Cention N with dual-cured Cention N.

Materials and methods

Cention N is mixed according to the proportions, as mentioned by the manufacturer. Dual cured samples are cured using a diode that emits blue light. Cylindrical plexiglass split mold of dimension 6 mm height, and 4 mm diameter used to fabricate samples for compressive strength. Compressive strength tested using Instron universal testing machine. Rectangular plexiglass split mold of dimension 25 mm length, 2 mm height, and 2 mm width were used to fabricate samples for flexural strength. Flexural strength tested using Instron universal testing machine. To compare the mean values independent t-test was used and the significance of the study was measured by calculating a p-value.

Result

There is no statistically significant difference between compressive strength and flexural strength of self-cured Cention N with dual-cured Cention N.

Conclusion

The type of polymerization does not affect flexural strength and compressive strength of Cention N.

Clinical Significance

Self-curing polymerization alone is sufficient for Cention N to achieve adequate compressive strength and flexural strength. So it can be inserted as a single layer on a prepared cavity and to fasten curing additional light curing can be used.

How to cite this article

Fousiya Ks, Balagopal VR, Suresh KJ, et al. Comparative Evaluation of Compressive Strength and Flexural Strength of Self-cured Cention N with Dual-cured Cention N: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(2):210-214.

Evaluation and comparison of flexural strength of Cention N with resin-modified glass-ionomer cement and composite - An in vitro study

AIM

The aim of this study was to evaluate and compare the flexural strength of Cention N with resin-modified glass-ionomer cement and nanohybrid composite.

MATERIALS AND METHODS

Samples were prepared by filling the stainless steel mold of dimension 2 mm × 2 mm × 25 mm with cement/composite immediately after mixing. Excess flash if any was removed by abrading it with abrasive paper. Then, the specimens were subjected to flexural strength measurement using universal testing machine. The results were then tabulated and statistically analyzed using one-way ANOVA followed by Tukey's multiple post hoc test.

RESULTS

The average flexural strength of NT Premium, Vitremer, and Cention N was 90.39 MPa, 46.59 MPa, and 62.88 MPa, respectively. There was a statistically significant difference between NT Premium and Cention N and NT Premium and Vitremer with P = 0.0002 and 0.0001, respectively.

SIGNIFICANCE

The flexural strength study can help us to choose a material for restoring Class V lesions and can also confirm whether Cention N, a new material, be a definite replacement for amalgam.

CONCLUSION

Cention N has proved to be a better material and can be a replacement for amagam and GIC.

In vivo evaluation of clinical performance of Cention N and glass ionomer cement in proximal restorations of primary molars

INTRODUCTION

Restoring a proximal lesion in primary tooth has met with many challenges which has led to evolution of many materials. An alternative to Glass Ionomer Cements which has fluoride releasing capacity, offers good bond strength and is esthetic have been long looked for.

AIM

This study aimed to compare the clinical performance of GIC and Cention N in proximal restorations of primary molars.

MATERIALS AND METHODOLOGY

A prospective study was conducted on 154 primary molars in patients aged between 5 and 8 years using a split-mouth design. Patients were divided into two groups. Control group restored with GIC and study group received Cention N. Both groups were assessed at baseline 3, 6 and 9 months according to Ryge criteria and data was statistically analysed using Fisher's Exact.

RESULTS

Statistically significant difference was found between GIC and Cention N restorations for color match at baseline and color stability at 3 months (P < 0.001), while the other parameters did not show any significant difference among the two restorative materials.

CONCLUSION

Cention N can be used as a suitable alternative to GIC for restoring Class II restorations in primary molars.

Comparative evaluation of mechanical and physical properties of a new bulk-fill alkasite with conventional restorative materials

PURPOSE

The physical and mechanical performance of a newly commercialized dental restorative material (alkasite) was compared with glass ionomer cement (GIC) and nano-hybrid composite.

METHODOLOGY

Human extracted premolars were used to investigate the shear bond strength. Restorative materials were placed on the dentine surface and were aged in deionized water for 14 days. The 3-D surface roughness was evaluated before and after chewing simulation cycles (50,000). The samples were fatigued mechanically using a chewing simulator and investigated with a scanning electron microscope (SEM).

RESULTS

For shear bond strength, alkasite showed significantly high values than GIC, whereas non-significant difference was observed between alkasite and nano-hybrid composite. After the chewing simulation (50,000 cycles), non-significant difference was found between GIC and nano-hybrid composite, where surface roughness values were highest for GIC and lowest for alkasite.

CONCLUSION

The newly developed restorative material (alkasite) has shown better results than existing restorative materials.

A Comparative Evaluation of Microleakage between Resin-Modified Glass Ionomer, Flowable Composite, and Cention-N in Class V Restorations: A Confocal Laser Scanning Microscope Study

Background:

Microleakage is a concern while restoring cervical lesions. Many products have attempted to minimize the interfacial gap between the tooth and restoration, the main pathway of microleakage.

Aims and Objective:

To compare and evaluate the microleakage in Class V cavity restored with nanohybrid flowable composite, Resin modified Glass Ionomer and Cention N.

Method:

Class V cavities were prepared on mandibular premolars on buccal surface with their occlusal margin placed in enamel and the gingival margin in dentin. The teeth were randomly assigned to three groups of 20 teeth each and restored with Flowable composite , Resin Modified GIC and Cention N. Samples were immersed in 0.5% Rhodamine dye, sectioned and microleakage measured using Confocal Laser Scanning Microscopy. Statistical analysis was done using Oneway ANOVA Bonferroni's test and Kruskal Waliis test.

Results:

The average depth of penetration of dye and scoring of depth were noted. On comparing dye penetration values between groups, RMGIC is compared with Flowable composite and Cention N, statistically significant result was obtained suggesting lesser dye penetration in RMGIC group (P < 0.001) where other comparison did not.

Conclusion:

RMGIC showed significantly less microleakage compared to the other two restorative materials used in the study and enamel margin of all restorations showed lesser microleakage than dentin margin.

Evaluation of compressive strength, shear bond strength, and microhardness values of glass-ionomer cement Type IX and Cention N

Aim:

This study aimed to compare the compressive strength, shear bond strength, and microhardness of glass-ionomer cement (GIC) Type IX and Cention N.

Materials and Methods:

Five samples each of GIC Type IX and Cention N were prepared for testing the shear bond strength, tensile strength, and microhardness. Cylinders of the samples measuring 1 cm diameter and 6 mm height were prepared for compressive strength and shear bond strength. For shear bond strength, these samples were embedded into acrylic blocks of dimensions 2 cm × 2 cm. Testing of shear bond strength and compressive strength was done by mounting the samples in a universal testing machine with a crosshead speed of 1 mm/min. The samples for microhardness were 1 cm diameter and 5 mm height. The samples were mounted on Vickers microhardness testing machine to test the microhardness.

Results:

The values for shear bond strength of Cention N were statistically highly significant (P < 0.01) as compared to GIC Type IX, whereas the compressive strength and microhardness values of Cention N were statistically significant (P < 0.5) as compared to GIC Type IX.

Conclusion:

The results suggest significantly higher values for mechanical properties of Cention N as compared to GIC Type IX.

Comparative evaluation of fluoride release and re-release and recharge potential of Zirconomer Improved and Cention

Background

The cariostatic action associated with fluoride-releasing restorative materials is mainly attributed to a sustained release of fluoride. This research aims on comparing Cention N and Zirconomer Improved in vitro fluoride release and re-release.

Methods

Test materials were grouped into two categories containing 15 samples each. The cumulative fluoride release and re-release measurements was made during 1st, 7th and 15th day. The independent sample t-test and paired t-test was used to check mean differences. The level of significance was kept at p<0.05.

Results

At day 1, 7 and 15 the initial fluoride release of zirconomer group was significantly higher (p<0.05) than the cention group. It was found that from day 1 to day 7 the mean initial fluoride release has significantly reduced (p<0.05) for both the groups. Similar results were also seen when comparisons were done between day 7 to day 15 (p<0.05) and day 1 to day 15 (p<0.05) for both the groups.

Conclusion

Zirconomer was more efficient in initial and fluoride re-release than the Cention N restorative material. Further in vivo studies with more parameters are recommended to evaluate fluoride release and cariostatic performance of Cention N and Zirconomer in real environmental circumstances.

Surface Nanohardness of Normal and Fluorosed Enamel Adjacent to Restorative Materials: An In Vitro Study and Polarized Light Microscopy Analysis

AIM AND OBJECTIVE

To evaluate nanohardness of normal and fluorosed enamel in teeth restored with Cention N (CN), Equia forte (EF), glass ionomer cement (GIC), and resin composite using the nanoindentation test.

MATERIALS AND METHODS

Eighty freshly extracted human premolars were selected. Standardized cavities were prepared on the buccal surface of normal (40) and fluorosed (40) teeth. Based on the type of the restorative material, the teeth were subgrouped into (n = 10): CN, EF, Type VIII GIC, and Tetric N-Ceram (TNC). The teeth were subjected to pH cycle (progressive caries test), which consisted of alternative demineralization (18 hours) and remineralization with artificial saliva (6 hours) for 3 consecutive days. Surface nanohardness was determined using a nanoindenter at distances of 100, 200, and 300 μm from the restoration-tooth margin. A polarized light Microscope was used to correlate the effect of remineralization on the enamel. Data were analyzed by one-way ANOVA with the Scheffe's post hoc and independent t-test.

RESULTS

Nanohardness values of the fluorosed/normal enamel adjacent to various materials in descending order were as follows: EF 3.67/2.95 GPa, GIC 3.33/3.15 GPa, CN 3.13/3.23 GPa, and TNC 1.17/1.82 GPa, respectively. Statistically significant differences were found among various materials in both types of the enamel (p < 0.05).

CONCLUSION

Based on the nanohardness test, EF can be a better choice for restoration in fluorosed teeth, followed by CN and GIC; GIC was better in normal enamel; however, this was not significant compared to CN and EF. Tetric N-Ceram composite resin had least influence on increasing the nanohardness of the adjacent enamel.

CLINICAL SIGNIFICANCE

The surface nanohardness of normal and fluorosed enamel can be influenced by the type of restorative material used. The results of present study deserve clinician's attention while selecting restorative materials especially in dental fluorosis.

Commercially Available Fluoride-Releasing Restorative Materials: A Review and a Proposal for Classification

Resin composite and glass ionomer cement (GIC) are the most commonly used dental materials to perform direct restorations. Both have specific characteristics that explain their popularity and their limits. More than 20 years ago, the first attempt (followed by others) to combine the advantages of these two families was performed with compomers, but it was not very successful. Recently, new formulations (also called 'smart materials') with claimed ion release properties have been proposed under different family names, but there are few studies on them and explanations of their chemistries. This comprehensive review aims to gather the compositions; the setting reactions; the mechanical, self-adhesive, and potential bulk-fill properties; and the ion release abilities of the large existing families of fluoride-releasing restorative materials and the new restorative materials to precisely describe their characteristics, their eventual bioactivities, and classify them for an improved understanding of these materials. Based on this work, the whole GIC family, including resin-modified and highly viscous formulations, was found to be bioactive. Cention N (Ivoclar Vivadent, AG, Schaan, Lietschentein) is the first commercially available bioactive resin composite.