Surface Microhardness Values Research Articles

Remineralizing Effect of Diode Laser and Amelogenin Peptide on Early Enamel Carious Lesion

Purpose: This study was done to investigate the efficacy of Diode laser andAmelogenin peptide on the remineralization of early enamel carious lesions. Materialsand methods: Artificial carious lesions were created on the buccal and lingual surfacesof 60 enamel specimens. Specimens were assigned to three groups of 20 specimensper each according to the remineralizing protocol: G1 (Diode laser), G2 (Diodelaser + Amelogenin peptide), G3 (Amelogenin peptide). The groups were furtherrandomly subdivided into two groups (n=10) whether specimens subjected to staticremineralization or pH cycling. Surface micro-hardness was assessed at baseline,demineralization and after treatment. Surface microhardness values were analyzed usingone way ANOVA and Tukey’s post-hoc test. Results: Surface microhardness values atstatic remineralization were; G1=G2>G3. No statistically significant difference wasfound between the three groups after pH cycling. Conclusion: Diode laser enhancedremineralization of incipient carious lesions compared to amelogenin peptides

Evaluation of different remineralization agents in the treatment of natural caries-affected dentin in permanent teeth.

In the preventive treatment protocol, providing remineralization of the tissue in demineralized dentin caries is an important step. In this in vitro study, the effectiveness of remineralization agents in natural caries-affected dentin (NCAD) were investigated. Forty caries slices were prepared from permanent molar dentin with International Caries Detection and Assessment System (ICDAS2) (Code3). The interventions with 8 days pH cycling were as follows: Deionized water (DW); 5% Sodium Fluoride (5%NaF) Varnish; Casein Phosphopeptide-Amorphous Calcium Fluoride Phosphate (CPP-ACFP); Calcium Glyserophosphate (CaGP) + Magnesium (Mg) + Xylitol. DIAGNOdent (Laser Fluorescence, LF), Surface Microhardness (SMH), and X-ray Fluorescence (XRF) Spectroscopy measurements were calculated before and after pH cycling. LF values decreased between 5% NaF, CCP-ACFP and CaGP. NCAD treated with 5% NaF, CaGP and CCP-ACFP exhibited statistically higher hardness compared to the control group. After 5% NaF application, SMH values were significantly higher than the others. There was no statistically significant difference between baseline and after pH cycling hardness of the control group. After cycling, XRF showed that Ca and P concentrations were increased in all groups. The application of agents used in the study could be recommended and promoted as a treatment option of caries dentin for conventional management of caries.

The anti-cariogenic effect of fluoride iontophoresis on sound enamel under different working conditions: an in vitro study

Objective. This study investigated the anti-cariogenic effect of fluoride iontophoresis on sound human enamel under different working conditions. Methods. One hundred and five enamel blocks were prepared and randomly assigned to seven different groups: Fluoride iontophoresis under different working conditions, including: different electric current intensities (0.2, 0.4, 0.6 mA) and durations of current application (3, 6, 9 min); No fluoride treatment (negative control); Fluoride immersion without iontophoresis (positive control). After 7 days of pH-cycling, morphology changes on enamel surfaces were examined by scanning electron microscopy (SEM), and Vickers surface microhardness (VH) values of enamel blocks before and after treatments were assessed using a Vickers microhardness tester. KOH-soluble fluoride (KOH-F) uptakes were measured by a fluoride ion-selective electrode. Results. Distinctly roughened enamel surfaces were showed in all treatment groups, with the greatest extent damaged surface in negative control group and the least in all the fluoride intophoresis groups. All the fluoride iontophoresis groups (except for the group under 0.2 mA) showed smaller reduction of VH values (p < 0.05) and greater KOH-F (p < 0.05) when compared with the negative and positive control groups. There was an increasing trend in the loss of VH and in fluoride uptakes with an increasing current intensity. Meanwhile, the reduction of VH values and KOH-F in Group I3 ( 0.6 mA) were significantly greater (p < 0.05) than those in Group I1 ( 0.2 mA). No significant differences of reduction of VH and KOH-F presented among the three groups applied with fluoride iontophoresis under different current durations. Conclusions. Fluoride iontophoresis resulted in a significantly increased KOH-F and a reduced loss of VH after the 7 days pH-cycling procedure, and its effectiveness was influenced by different electric current intensities but not influenced by different current durations.

The Remineralization Effect of Calcium Glycerophosphate in Fluoride Mouth Rinse on Demineralized Primary Enamel: An in vitro Study.

To evaluate the remineralization effect of a fluoride mouth rinse containing calcium glycerophosphate in fluoride mouth rinse based on the surface microhardness of demineralized primary enamel. 40 sound primary incisors were placed into self-curing acrylic resin and subjected to a demineralizing solution for 5 days, resulting in the formation of artificial caries. The teeth were categorized into four groups (n = 10): group I artificial saliva, group II sodium fluoride, group III sodium fluoride + sodium monofluorophosphate, and group IV sodium monofluorophosphate + calcium glycerophosphate. The specimens received a pH cycling procedure and were submerged twice in their assigned groups for 7 days. The baseline, after demineralization, and after remineralization surface microhardness values were determined. One-way analysis of variance (ANOVA) was used to analyze the mean surface microhardness between groups and one-way repeated measures ANOVA for the mean surface microhardness within each group and Bonferroni's for multiple comparisons at 95% confidence level. The percentage recovery surface microhardness was determined by calculating the average surface microhardness. After demineralization, the mean surface microhardness in all groups significantly decreased. After remineralization, group I had the lowest surface microhardness values and the percentage recovery surface microhardness (P value < 0.001), and group IV had the highest surface microhardness values and the percentage recovery surface microhardness (P value < 0.001). No significant difference was found between groups II and III (P value = 0.365). Fluoride mouth rinse containing calcium glycerophosphate has a remineralization effect on demineralized primary enamel.

Remineralization Effect of Calcium Glycerophosphate in Fluoride Mouth Rinse on Eroded Human Enamel: An In Vitro Study.

The aim of this in vitro study was to evaluate the remineralization effect of calcium glycerophosphate (CaGP) in fluoride mouth rinse on permanent enamel eroded by a soft drink. Forty sound permanent premolars were embedded in self-curing acrylic resin and immersed in Coca-Cola to create erosive lesions. The teeth were divided into four groups (n = 10): Group I artificial saliva; Group II sodium fluoride; Group III sodium fluoride + sodium monofluorophosphate; and Group IV sodium monofluorophosphate + CaGP. The specimens in the assigned groups underwent pH cycling for ten days. The baseline, after erosion, and after remineralization surface microhardness (SMH) values were determined. The data were analyzed by one-way analysis of variance (ANOVA). The mean SMH value between groups and one-way repeated measures ANOVA for the mean SMH value within each group and Bonferroni's for multiple comparisons at a 95% confidence level were determined. The average SMH was used and calculated as the percentage recovery of SMH. After being eroded by the cola soft drink, the mean SMH values in all groups were significantly decreased. After remineralization, Group I had the lowest %SMHR. The %SMHR of Groups II, III, and IV were significantly higher than Group I (P < 0.001). However, there were no significant differences among Groups II, III, and IV (P > 0.05). Fluoride mouth rinse with and without CaGP showed similar efficacies in remineralizing eroded permanent enamel.

In Vitro Evaluation of the Effect of Fluoride Varnish Application Frequency on Initial Enamel Lesions

Purpose: The aim of this study is the in vitro evaluation of the effect of fluoride varnish application at different frequencies on initial enamel lesions by surface microhardness (SMH) measurements. Material and Methods: This in vitro experimental study was performed on 80 extracted unerupted third molar teeth. The teeth were divided randomly into 4 groups: Group 1: Fluoride varnish application once a year, Group 2: Fluoride varnish application 4 times at 1 week intervals, Group 3: Fluoride varnish application 4 times a year with an interval of 3 months, Group 4: Application of fluoride varnish twice a year at 6-month intervals. Artificial enamel carious lesions were created by inserting the specimens in demineralization solution for 96 hours. The Vicker’s microhardness number (VHN) was measured at baseline, after demineralization and after fluor varnish application and 1 year after fluoride treatments of each group. The percent change in surface microhardness (% SMH change) was also calculated. Anova and Kruskall-Wallis H test, t-test and/or Wilcoxen sign test were used with 95% confidence levels to compare differences. Results: The surface microhardness values and recovery of surface hardness values of the groups were found as follows: Group 3&amp;gt; Group 2&amp;gt;Group 4&amp;gt; Group 1. VHN of Group 3 was statistically significantly higher than other groups (p&amp;lt;0.05). Conclusion: Fluoride varnish application 4 times a year with an interval of 3 months showed significantly higher enamel SMH than that of the other groups (p&amp;lt;0.05).

The Effect of Gastric Acid on the Surface Properties of Different Universal Composites: A SEM Study.

The aim of this study is to compare surface roughness and microhardness changes of three monochromatic (Omnichroma, Vittra Unique, and Charisma Diamond One) and three universal shade (Neo Spectra ST, G-ænial A'CHORD, and Nova Compo C) resin composites after exposure to simulated gastric acid. A total of 144 disc-shaped specimens (24 discs of each composite resin) were prepared using plexiglass molds (R = 5 mm × h = 2 mm) for evaluation from each material. Specimens of each material were divided into two main groups for the evaluation of the microhardness and surface roughness and also two subgroups for 7- and 14-day exposures to simulated gastric acid. Initial microhardness and surface roughness measurements of all samples were measured before immersion (T1) followed by exposing the samples to simulated gastric acid for 7 days (T2) and 14 days (T3), and then, the microhardness and roughness measurements were repeated. Randomly selected specimens of each material for each of the time intervals (T1, T2, and T3) were evaluated with scanning electron microscopy (SEM). One-way ANOVA revealed that the surface roughness and hardness values of all tested composite resin restorative materials show no statistically significant difference for the initial (T1) value (p > 0.05). Regarding the 7th day (T2) and 14th day (T3) surface roughness and microhardness value of all composites, there are statistically significant differences between the groups (p < 0.05), while there was no statistically significant difference between the surface hardness reduction percentage between the time intervals (p > 0.05). As a result of this in vitro study, increase in surface roughness and decrease in microhardness of the tested universal composite materials when exposed to simulated gastric acid were statistically significant.

Water as Veneering Modeling Liquid Affects Microhardness of Glassy Matrix Veneering Ceramic.

To evaluate the effect of different veneering liquids used for modeling on microhardness, fracture toughness and biaxial flexural strength of a glass-veneering ceramic. The manufacturer recommended modeling liquid (ML), distilled water (DW), isopropyl alcohol (IA), 0.5% (P05), 1% (P1), and 2% (P2) polyethylene glycol solutions were mixed with feldspathic ceramic powder to form disc-shaped samples (n=20, 15 mm × 1.2 mm). After sintering, samples were mirror-polished and subjected to Vickers indentation (n=5) for measurement of microhardness and fracture toughness. The remaining 15 samples from each group were subjected to biaxial flexural strength. Data were subjected to one-way ANOVA and Weibull analysis. The microhardness was affected by veneering liquid (p=0.002): DW promoted higher microhardness values than ML and IA. Fracture toughness (p=0.301) and flexural strength (p=0.930) were not affected by the veneering liquid but Weibull parameters were affected. All groups presented surface pores under high magnification. Even though the use of DW led to higher values of surface microhardness than the ML, all obtained values are inside the range of enamel microhardness values reported in the literature. Such parameters may affect antagonist wear and should be reported in clinical trials.

Effect of Eggshell Powder and Nano-Hydroxyapatite on the Surface Roughness and Microhardness of Bleached Enamel.

The aim of the study was to evaluate the remineralizing potential of prepared solutions of eggshell powder (ESP) and nano-hydroxyapatite (nHA) on the surface roughness and microhardness of bleached enamel. Fifty bovine anterior teeth were selected and cleaned then bleached using a chemically activated in-office bleaching agent then the teeth were randomly allocated into five groups (n = 10) according to the tested remineralizing agents (10% ESP solution, 10% nHA solution, and MI Paste Plus) into; control, bleached, bleached + ESP solution, bleached + nHA solution, and bleached + MI Paste Plus groups. Then, the teeth were tested for surface roughness and microhardness of the bleached enamel, respectively. There was a statistically significant difference in the surface roughness and microhardness values of the tested groups. The highest surface roughness mean value was found in bleached enamel group, while the least mean value was found in the control group. The highest mean microhardness value was found in the bleached enamel + ESP solution group, while the least mean value was found in the bleached enamel group. The application of the tested remineralizing agents following the bleaching procedure had improved the surface roughness and microhardness of the bleached enamel. ESP and nHA present promising and potent remineralizing agents.

The Effects of Selected Mouthwashes on the Surface Microhardness of a Single-shade Universal Resin Composite: In Vitro Study

Aim: To investigate the effects of selected alcohol-free mouthwashes with different formulations (zinc-hydroxyapatite, hydrogen peroxide, and sodium fluoride) on the surface microhardness of a single-shade universal resin composite. Materials and Methods: Forty disc-shaped specimens (8 × 2 mm) from the universal resin composite (Omnichroma®), and a nano-hybrid composite (Tetric® N-Ceram) were prepared. After polymerization, baseline surface microhardness values were recorded using Vickers microhardness tester. The samples from each material were randomly assigned to 4 groups ( n = 10) and immersed in 20 ml of the mouthwashes: Biorepair®, Listerine®, Colgate® Optic White, and distilled water (control). The samples were kept in the immersion solutions for 24 hours, and post-immersion microhardness values were recorded. Data were analyzed with one-way ANOVA and paired sample t-tests at p &lt; .05. Results: Significant reduction in microhardness was observed in all resin composite groups after immersion in the mouthwashes compared to baseline values ( p &lt; .0001). The highest microhardness reduction in Omnichroma® group was observed after immersion in Colgate® Optic White; and Tetric® N-Ceram group after immersion in Listerine® mouthwash. For both materials, the least reduction in microhardness was observed after immersion in Biorepair®. Microhardness values for Omnichroma were significantly higher than Tetric® N-Ceram ( p &lt; .0001). However, Omnichroma exhibited a significantly greater reduction in microhardness after immersion in the tested mouthwashes. Conclusion: In vitro simulated use of the investigated mouthwashes negatively affected the surface microhardness of both tested resin composites. The observed effects were both mouthwash and material dependent.

Effect of Metal-Cored Filler Wire on Surface Morphology and Micro-Hardness of Regulated Metal Deposition Welded ASTM A387-Gr.11-Cl.2 Steel Plates.

Environmental and human-friendly welding is the need of the hour. In this context, this study explores the application of the regulated metal deposition (RMD) technique for ASTM A387-Gr.11-Cl.2 steel plates. To examine the effect of metal-cored filler wire (MCFW), MEGAFIL 237 M was employed during regulated metal deposition (RMD) welding of 6 mm thick ASTM A387-Gr.11-Cl.2 steel plates. The welding was carried out at an optimized current (A) of 100 A, voltage (V) of 13 V, and gas flow rate (GFR) of 21 L/min. Thereafter, the as-welded plates were examined for morphological changes using optical microscopy. Additionally, the micro-hardness of the as-welded plates was measured to make corroboration with the obtained surface morphologies. In addition to this, the as-welded plates were subjected to heat treatment followed by surface morphology and micro-hardness examination. A comparison was made between the as-welded and heat-treated plates for their obtained surface morphologies and microhardness values. During this, it was observed that the weld zone of as-welded plates has a dendritic surface morphology which is very common in fusion-based welding. Similarly, the weld zone of heat-treated plates has a finer and erratic arrangement of martensite. Moreover, the obtained surface morphologies in the weld zone of as-welded and heat-treated plates have been justified by their respective hardness values of 1588.6 HV and 227.3 HV.

Assessment of influence of LED curing units used on microhardness of resin-modified glass ionomer sealants

Aim: Resin modified glass ionomer (RMGI) is class of material that can be used as sealant for preventing and arresting the progression of caries in pits and fissures. As these are hybrid materials, their properties can be affected by factors related to the polymerization process. Therefore, this study aimed to evaluate the influence of different generations of LED curing units (Elipar DeepCure-L and VALO Grand) on Knoop microhardness values (KHN) of RMGI sealants (Clinpro XT and Vitremer). Methods: Forty cylindrical specimens (6mm ø x 1 mm high) were prepared according to the manufacturer’s instructions and divided into four groups (n=10) according to the type of RMGI and LED used. The KHN of the top surface of each sample was calculated 7 days after light-curing. Data were submitted to two-way ANOVA (α = 0.05). Results: Vitremer had higher KHN values than Clinpro XT after using both LEDs (p&lt;0.0001), but especially when light-cured with the use of VALO Grand (p&lt;0.0001). Whereas the KHN value of Clinpro was not influenced by the LED device (p&gt;0.05). Conclusions: Top surface microhardness values of RGMI sealants were affected by both material composition and generations of LED curing units used. Third generation LED curing units seemed to be more efficient for the polymerization of RMGI-based sealants.

COMPARISON OF THE MICROHARDNESS OF BULK FILL COMPOSITES

The aim of this study is to compare the microhardness of five different bulk fill composites (SDR, TEC, XTF, SF, FBF). A total of 25 cylindrical molds were prepared. Composite resin was placed in each mold in sequence, at one time, by condensing it thoroughly. Then, the polymerization of the composites was achieved with the LED light device which was applied for 20 seconds. Microhardness measurements of the samples were made with the classical Vicker's test. The data of our study were evaluated by using the Kruskal Wallis H test with the SPSS 20.0 package program. When the measured surface microhardness values were compared between the groups; microhardness values SDR and FBF groups were found to be significantly lower than TEC, XTF and KSF groups (p&amp;lt;0.05). When the sub-surface microhardness values were compared between the groups; the microhardness value of the SDR group was found to be significantly higher than the FBF group, and significantly lower than the TEC, XTF and KSF groups (p&amp;lt;0.05). When both the lower and upper surface microhardness values were compared between the groups, XTF was found to be the bulk fill composite group with the best microhardness.

Comparison of calcium-based technologies to remineralise enamel subsurface lesions using microradiography and microhardness

Assessment of enamel subsurface lesion remineralisation is essential for the evaluation of novel remineralisation technologies. The gold standard to assess subsurface mineral gain of enamel lesions is transverse microradiography (TMR). However, some studies have utilised surface microhardness (SMH) to evaluate efficacy of remineralisation agents. The aim of this study was to assess remineralisation of enamel subsurface lesions using TMR and SMH after in vitro treatment with calcium-containing technologies, and to test correlation between the TMR and SMH measurements. The parameters obtained from the TMR and SMH analyses of enamel subsurface remineralisation were not significantly correlated. Furthermore, the enamel subsurface remineralisation as measured by TMR was significantly correlated with the water-soluble calcium concentration of the remineralisation products. Scanning electron microscopy revealed surface precipitates formed by specific remineralisation treatments obfuscated accurate assessment of remineralisation by SMH. It was concluded that TMR is a more appropriate method for analysis of enamel subsurface remineralisation, and that SMH values of remineralised enamel should be interpreted with caution. Using TMR the level of remineralisation (%R) by the different technologies was CPP-ACP/F (31.3 ± 1.4%); CPP-ACP (24.2 ± 1.4%); CaSO4/K2HPO4/F (21.3 ± 1.4%); f-TCP/F (20.9 ± 1.0%); Nano-HA/F (16.3 ± 0.3%); Nano-HA (15.3 ± 0.6%) and F alone control (15.4 ± 1.3%).

The Effect of Two Different Light-Curing Units and Curing Times on Bulk-Fill Restorative Materials.

This study aimed to evaluate the effect of two different light-curing units and curing times on the surface microhardness (SMH), compressive strength (CS), and volumetric shrinkage (VS) of four restorative materials (FiltekTM Z250, FiltekTM Bulk Fill Posterior, Beautifil® Bulk Restorative, ACTIVATM BioACTIVE). For all tests, each material was divided into two groups depending on the curing unit (Woodpecker LED-E and CarboLED), and each curing unit group was further divided into two subgroups according to curing time (10 s and 20 s). SMH was evaluated using a Vickers hardness tester, CS was tested using a universal testing machine, and VS was measured using video imaging. In all the restorative materials cured with Woodpecker LED-E, the 20 s subgroup demonstrated significantly higher SMH values than the 10 s subgroup. In both light-curing time subgroups, the CarboLED group showed significantly higher CS values than the Woodpecker LED-E group for all restorative materials except FiltekTM Bulk Fill Posterior cured for 20 s. ACTIVATM BioACTIVE showed significantly greater volumetric change than the other restorative materials. A higher curing light intensity and longer curing time had a positive effect on the SMH and CS of the restorative materials tested in this study. On the other hand, curing unit and time did not show a significant effect on the VS values of restorative materials.

Remineralizing Potential of Milk and GC Tooth Mousse on Demineralized Human Enamel: An In Vitro Comparative Evaluation

Abstract Introduction Caries initiation is associated with demineralization of the subsurface tooth enamel. Today, bioactive agents based on milk products have been developed to enhance remineralization under cariogenic conditions. However, there is limited information on the remineralization potential of milk. Materials and Methods Fifty enamel specimens were prepared from sound human premolars. All enamel specimens were then placed in demineralizing solution for 4 days at 37°C to produce artificial carious lesion. Baseline surface microhardness (SMH) was evaluated using Vickers indenter. Enamel specimens were then randomly divided into three groups. Group 1 specimens were kept in artificial saliva, whereas group 2 and 3 enamel specimens were treated with milk and GC tooth mousse, respectively, for 5 minutes twice daily for 21 days. Post-treatment SMH measurements of all specimens were evaluated on the 7th, 14th, and 21st day. Data was statistically analyzed using one-way analysis of variance test and Tukey honest significant difference post-hoc test. Results There were no significant differences in the SMH values in the control group at any time interval. There were statistically significant increases in the post-SMH values in milk and GC tooth mousse (p &lt; 0.001) at the end of 21st day of remineralization. Conclusion Milk showed remineralization potential comparable to that of GC tooth mousse.

Evaluation of the Effect of Two Polishing Techniques and Thermocycling Process on Surface Roughness, Hardness, and Color Stability of Composites

Objectives: The aim of this study was to evaluate the effect of two polishing techniques and 10.000 thermocycles on the color stability, surface roughness, and hardness of two nanohybrid (Tetric N-Ceram, Escom100) and one bulkfill (Filtek) resin composites. Methods: A total of 60 specimens were prepared using three resin composites and 20 discs from each composite. Specimens for each composite were randomly divided into two different polishing groups (Optrapol rubber and Sof-Lex discs) (n=10). Surface roughness (Ra, μm), microhardness (VHN), and color change (ΔE00) values were measured pre- and post-thermocycling. Two-way analysis of variance (ANOVA) was used to evaluate the effect of independent variables. Bonferroni test was used for multiple comparisons (p&lt;0.05). Results: Escom100 with Sof-Lex found the highest mean ΔE00 and Filtek bulk-fill composite with Optrapol found the lowest mean ΔE00. Escom100 with Sof-Lex exhibited the lowest Ra values in all groups. Sof-Lex discs exhibited smoother surfaces than Optrapol in all groups.. Among the polishing groups, Optrapols’ VHN values were higher than Sof-Lex’s (p&lt;0.05). Conclusions: Filtek bulk-fill with Optrapol in terms of color change and microhardness; Escom100 (nanohybrid) with Sof-Lex in terms of smoothness, can be recommended for clinical use. After thermocycling, surface roughness values increased and surface hardness values decreased in all composite resins.

Comparison of Remineralization Potential of Casein Phosphopeptide: Amorphous Calcium Phosphate, Nano-hydroxyapatite and Calcium Sucrose Phosphate on Artificial Enamel Lesions: An In Vitro Study.

Aim and objectiveTo evaluate and compare the remineralization potential of CPP-ACP, nano-hydroxyapatite, and calcium sucrose phosphate toothpaste on artificial enamel caries lesions by means of microhardness testing.Materials and methodsTwenty sound human primary molars, extracted for therapeutic reasons were selected for this study. From each tooth, two enamel specimens were prepared and embedded in acrylic resin blocks, and each block contains five tooth samples. After polishing, the baseline hardness of the enamel surface (KHN) was determined by Knoop microhardness testing. Then the specimens were randomly assigned into four groups (n = 10), according to the remineralizing agent used: group I: Control, group II: GC Tooth MousseTM (CCP-ACP), group III: AcclaimTM (nano-HAP), and group IV: EnaFix (CaSP). The specimens were then immersed in a demineralizing solution and post-lesion KHN values were obtained as baseline measurements. Later remineralizing agent was applied and after 7 days of remineralization, posttreatment KHN tests were conducted.ResultsData were analyzed using paired t- test, analysis of variance, and Tukey HSD test. Mean enamel surface microhardness (KHN) values after remineralization shows that group IV (EnaFixTM) had maximum hardness number (114.71 ± 12.27) followed by group III (Acclaim) (85.14 ± 22.82) and group II (GC Tooth Mousse) (56.42 ± 19.90). The difference was statistically significant (p < 0.001). Similarly the %SMHR was also highest in group IV (EnaFix), followed by group III (Acclaim) and group II (GC Tooth Mousse).ConclusionEnaFix (calcium sucrose phosphate) shows a maximum increase in the enamel surface microhardness followed by Acclaim (nano-HAP) and GC Tooth Mousse.Clinical significanceCalcium Sucrose Phosphate in toothpaste strengthened the enamel more than nano hydroxyapatite and CPP-ACP, and can be an alternative to the use of fluoride toothpaste in children.How to cite this articleSebastian R, Paul ST, Azher U, et al. Comparison of Remineralization Potential of Casein Phosphopeptide: Amorphous Calcium Phosphate Nano-hydroxyapatite and Calcium Sucrose Phosphate on Artificial Enamel Lesions: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(1):69-73.

Effects of thickness and aging of bulk-fill composite resins on surface microhardness and fluorescence properties

Objective: Evaluation of various bulk-fill composite materials with respect to the microhardness values of the top and base surfaces upon variation in the composite thickness. The effect of aging and comparison of the fluorescence properties exhibited by the materials at different thicknesses will also be examined. Materials and Methods: For all samples, calculations were carried out using a family F probability, with a repeated family design including interactions within and among the factors, which resulted in 135 sample units, with 27 samples per experimental group. Z350, AURA, TETRIC, SDR, and FBF composites were employed with thicknesses of 2, 3, and 4 mm, initially being submitted to microhardness measurements (n=9). Aging was carried out using an aqueous ethanol solution. After aging the microhardness values of the samples were measured again, and a comparative analysis was performed for the fluorescence of all samples. Results: Aging, sample thickness, and the type of material were found to affect both the surface microhardness and the fluorescence values. In addition, the AURA and SDR bulk-fill composites were the least susceptible to differences in thickness in terms of the top and base surface microhardness values. Conclusions: Although the manufacturers of some bulk-fill composites recommend the use of material increments of 4 mm, the results of this study suggest that further research is required before clinical application.

Effect of Preheating and Vibration on Microhardness and Microleakage of Microhybrid Resin Composite (In Vitro Study)

BACKGROUND: Preheating and sonic vibration are two methods for the treatment of microhybrid resin composites that may effect on their mechanical and physical properties. AIM: This study was conducted to assess the effect of using preheating and sonic vibration on microhardness and microleakage of microhybrid resin composite METHODS AND MATERIALS: For microhardness test, a total of 30 samples of resin composite discs were prepared. Samples were divided into three groups according to the method of treatment of resin composite, controlled group (T0), preheated group (T1), and sonic vibration group (T2). Surface microhardness values were evaluated at baseline and after thermocycling. For microleakage test, a total of 30 Class-V cavities were prepared on the labial surfaces of extracted human anterior teeth. The cavities were then divided into three groups according to the method of resin composite treatment as mentioned before in the microhardness test. All samples were sectioned; then two-dimensional cross-sectional images from each sample. Each cross-sectional image was analyzed using Image J software to quantify interfacial microleakage at the cavity floor. STATISTICAL ANALYSIS USED: Two-way ANOVA analysis was used to test the effects of thermocycling on three groups of each test. One-way ANOVA was used to compare between three different methods of resin composite treatment. RESULTS: For microhardness at baseline revealed that the highest mean value was recorded for the control group, followed by the sonic vibration group meanwhile, the lowest mean value was recorded for the sonic vibration group, followed by preheated group at microleakage test. CONCLUSION: Preheating and sonic vibration of microhybrid resin composite does not improve its microhardness; however, sonic vibration provides better marginal adaptation than the preheating and the conventional methods.