In vitro remineralization of adjacent interproximal enamel carious lesions in primary molars using a bioactive bulk-fill composite.

BACKGROUND: Surface remineralization is recommended for the management of active non-cavitated interproximal carious lesions in primary teeth. According to the American Academy of Pediatric Dentistry, a recently recognized category of materials called bioactive restorative materials can be used for remineralization. This study aimed to evaluate the release of fluoride (F), calcium (Ca) and phosphate (P) ions from Predicta® Bioactive Bulk-fill composite compared with EQUIA Forte® and Filtek™ Z350 and to determine the remineralization effect of these 3 restorative materials on adjacent initial interproximal enamel carious lesions. METHODS: The release of F, Ca and P ions from 3 groups ((n = 10/group) (Group 1- Predicta®, Group 2- EQUIA Forte® and Group 3- Filtek™ Z350)) was determined at 1st, 4th, 7th and 14th days. After creating artificial carious lesions, human enamel samples were randomly assigned into 3 groups (n = 13/group) which were placed in contact with occluso-proximal restorative materials and exposed to a 14-day pH cycling period. Surface microhardness was determined using a Knoop microhardness assay at baseline, after artificial carious lesions formation and after pH cycling. The difference in the percentage of surface microhardness recovery (%SMHR) among groups was compared. Mineral deposition was analyzed with energy-dispersive x-ray spectroscopy (EDS) and the enamel surface morphology was evaluated with scanning electron microscopy (SEM). Kruskal-Wallis's test with Dunn's post hoc test and one-way ANOVA with Tukey's post hoc test were used for data analysis. RESULTS: EQUIA Forte® released the highest cumulative amount of F and P ions, followed by Predicta® and Filtek™ Z350. Predicta® released higher amount of Ca ions than EQUIA Forte® and Filtek™ Z350. Predicta® demonstrated the highest %SMHR, followed by EQUIA Forte® and Filtek™ Z350. There was a significant difference in the %SMHR between Predicta® and Filtek™ Z350 (p < 0.05). However, EQUIA Forte® demonstrated the highest fluoride content, followed by Predicta® and Filtek™ Z350. The SEM images of EQUIA Forte® and Predicta® revealed the greater mineral deposition. CONCLUSION: Predicta® demonstrated a marked increase in surface microhardness and fluoride content of adjacent initial interproximal enamel carious lesions in primary molars compared with Filtek™ Z350. Predicta® is an alternative restorative material to remineralize adjacent initial interproximal enamel carious lesions in primary molars, especially in high-risk caries patients.

Mechanical properties evaluation of two resin-based three-dimensional printing materials and dentine for endodontic training model fabrication: In vitro study.

The objective of the study was to compare 4 mechanical properties of two 3-D printing resins with dentine. Four mechanical tests were performed on dentine specimens, VeroClear resin and Splint resin with 15 samples each. Vickers hardness test, samples were subjected to a 300-g load for 10 s. Flexural strength test, 8-millimetre, beam-shaped specimens were tested using the three-point bending method. Drilling force was measured on flat-surface specimens. Intra-canal torque was measured on specimens imitating root canals. The results were analysed using the Kruskal-Wallis and Mann-Whitney tests with adjusted Bonferroni's p-value (p < 0.05). Dentine exhibited the highest mechanical properties in all the tests. VeroClear's flexural strength and drilling force were higher, while the surface hardness was lower than that of Splint resin. The intra-canal torque of dentine and VeroClear resin were not significant and higher than that of Splint resin. VeroClear's mechanical properties were closer to dentine than Splint resin.

Effect of simulated gastric acid on aesthetical restorative CAD-CAM materials' microhardness and flexural strength.

Background: Gastric acid, which is among erosive substances, gradually rises to the mouth in individuals with reflux and bulimia nervosa disorders, and this causes various effects on dental restorations. Aim: The objective of this study is in vitro investigation of gastric acid's effect on flexural strength and hardness on aesthetic restorative computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: For this study, four materials have been used, namely Enamic (Vita), Superfect Zir (Aidite) Zirconia, IPS e.max CAD (Ivoclar Vivadent), and Mark II (Vita). From these four different materials, 24 samples with 14 × 4 × 1 dimensions in rectangular prism form are used, which makes a total of 96 samples. One group was separated as the control group, while the rest was allowed to wait at 37°C, 5 ml gastric acid for 96 hours. Hardness value and flexural strengths were measured as pre-exposure and post-exposure to gastric acid. Results: There is a statistically significant difference between the groups in terms of the amount of decrease in the mean hardness after exposure to gastric acid compared to pre-exposure values (p: 0,000; P < 0,05). There was no statistically significant difference between the groups in terms of the amount of decrease in the post-exposure average flexural strength compared to the pre-exposure value (p: 0.063; P > 0.05). There is a statistically significant difference between the groups in terms of the average flexural strength after exposure to the acid. Conclusions: According to the data obtained, it was concluded that exposure to gastric acid affects the hardness and flexural strength properties of dental restorative ceramic materials.

Gastric acid challenge of lithium disilicate-reinforced glass-ceramics and zirconia-reinforced lithium silicate glass-ceramic after polishing and glazing-impact on surface properties.

OBJECTIVES: To investigate the impact of simulated gastric acid on the surface properties of lithium disilicate-reinforced glass-ceramics and zirconia-reinforced lithium silicate glass-ceramic after certain polishing and glazing procedures. MATERIALS AND METHODS: Four different types of square-shaped specimens (10 × 10 × 2 mm3, n = 13) were manufactured: lithium disilicate-reinforced glass-ceramic milled and polished (LDS-P); milled, polished, and glazed (LDS-PG); milled, glazed, and no polishing (LDS-G); and milled and polished zirconia-reinforced lithium silicate glass-ceramic (ZR-LS). Specimens were immersed in hydrochloride acid (HCl 0.06 M, pH 1.2) to simulate gastric acid irritation and stored in the acid for 96 h in 37 °C. Specimen weight, surface gloss, Vickers surface microhardness and surface roughness (Ra, Rq, with optical profilometer), and surface roughness on nanometer level (Sq, Sal, Sq/Sal, Sdr, Sds with atomic force microscope) were measured before and after the acid immersion. RESULTS: ZR-LS specimens lost significantly more weight after acid immersion (p = 0.001), also surface microhardness of ZR-LS was significantly reduced (p = 0.001). LDS-G and LDS-PG showed significantly lower surface roughness (Sa, Sq) values compared to LDS-P before (p ≤ 0.99) and after (p ≤ 0.99) acid immersion and ZR-LS after acid immersion (p ≤ 0.99). CONCLUSIONS: Gastric acid challenge affects the surface properties of lithium disilicate-reinforced glass-ceramic and zirconia-reinforced lithium silicate glass-ceramic. Glazing layer provides lower surface roughness, and the glazed surface tends to smoothen after the gastric acid challenge. CLINICAL RELEVANCE: Surface finish of lithium disilicate-reinforced glass-ceramic and zirconia-reinforced lithium silicate glass-ceramic has a clear impact on material's surface properties. Gastric acidic challenge changes surface properties but glazing seems to function as a protective barrier. Nevertheless, also glazing tends to smoothen after heavy gastric acid challenge. Glazing can be highly recommended to all glass-ceramic restorations but especially in patients with gastroesophageal reflux disease (GERD) and eating disorders like bulimia nervosa.

Effect of Dental Varnishes in Prevention of Enamel Demineralization Adjacent to Orthodontic Brackets.

Aim: The aim of the current research was to assess the ability of different dental varnishes in averting enamel demineralization adjoining the orthodontic brackets. Materials and Methods: Seventy-five premolars devoid of dental caries that were subjected to extraction for orthodontic purposes were employed in this research. The surface of enamel was etched with 37% phosphoric acid and subjected to primer application. Individual brackets were placed on the midregion of the buccal surfaces of the premolars with Transbond™ XT adhesive. Postbracket bonding, the dry premolar tooth samples were set aside cautiously. The samples were then allocated to three groups: Group I: Duraphat Varnish, Group II: Clinpro XT Varnish, and Group III: Profluorid Varnish. Every sample was independently subjected to immersion in demineralizing solution for a period of 96 h at 37°C in an incubator. Areas of demineralization were evaluated by documenting the microhardness along the severed surface using a microhardness tester equipped with a Vickers diamond. Results: The highest surface microhardness was noted with Profluorid Varnish group at 328.48 ± 1.12 in pursuit by Clinpro XT Varnish group at 322.08 ± 0.04 as well as Duraphat Varnish group at 307.42 ± 0.28 with a statistically noteworthy dissimilarity amid the groups. Conclusion: In conclusion, the three varnishes employed had an influence on the prevention of enamel demineralization surrounding the orthodontic brackets. Profluorid varnish however exhibited maximum efficiency in avoiding enamel demineralization versus Clinpro XT varnish as well as Duraphat varnish group.

Impact of Various Remineralizing Agents on Artificial White Spot Lesion on Primary Teeth-A Comparative Study.

Aim: The aim of the current research was to assess the effectiveness of different remineralizing substances on artificial white spot lesions on deciduous teeth. Materials and Methods: 45 deciduous teeth without dental caries constituted the study group for this in vitro research. A 3 mm by 3 mm window of enamel was uncovered at the occluso-gingival midpoint of the coronal labial surface; an acid-resistant nail varnish was coated alongside the uncovered enamel surface of all specimens, employing vertical strokes. Demineralization was executed for the tenure of 72 hours at 37°C temperature in an incubator. The forty-five specimens, fifteen in each group, were assigned to the investigational groups plus a control group as: Group A: Control, Group B: Calcium sucrose phosphate (CaSP), Group C: Casein phosphopeptide-amorphous calcium phosphate-fluoride (CPP-ACPF). Microhardness tester was employed for testing the microhardness of the enamel surface using a Vickers diamond indenter laden with twenty-five milligrams for approximately ten seconds. Vickers hardness number (VHN) calculations for the microhardness were performed at baseline and on the fourteenth day. Results: The CPP-ACPF group exhibited greater mean microhardness value at 236.14 ± 2.12, in pursuit by CaSP group with a score of 231.98 ± 3.16 and then the control group at 220.22 ± 5.08. An extremely statistically significant difference was seen amid the groups. Conclusion: The current research arrived at a conclusion that both the remineralizing substances were certainly efficient in handling early dental caries, and additionally, casein phosphopeptide-amorphous calcium phosphate-fluoride (CPP-ACPF) was found highly efficient as a remineralizing substance, in pursuit by calcium sucrose phosphate (CaSP).

In Vitro Evaluation of the Effects of Different Beverages on the Surface Microhardness of a Single-Shade Universal Composite.

AIM: The aim of this in vitro study was to analyze the influence of various beverages on the surface microhardness of a single-shade composite resin. MATERIALS AND METHODS: Seventy-five Omnichroma composite discs were fabricated and divided into five subgroups according to the beverages. The groups were Group A: tea; Group B: coffee; Group C: beer; Group D: whisky; and Group E: artificial saliva. The samples were immersed in their respective beverages for 15 minutes per day for 15 days. The Vickers microhardness values were taken before and after the immersion of the composite disc samples in their respective beverages. A one-way analysis of variance (ANOVA) test was conducted using IBM SPSS Statistics software version 23 (IBM Corp., Armonk, New York, USA), with a statistical significance level of 5%. RESULTS: It was observed that there was a reduction in the surface microhardness of the composite resin after immersion in most of the solutions. An increase in the mean percentage change of surface microhardness was observed in the beer group (29%; mean difference = 16.52±12.05), followed by the coffee group (27.2%; mean difference = 15.51±9.28). The least mean percentage change in microhardness was noted in group E, artificial saliva (8.5%; mean difference = 4.81±3.04). CONCLUSION: The surface microhardness of composite resin can be influenced by the type of beverages used for immersion and the duration of immersion. However, it is important to note that the interaction between composite resin and various beverages is influenced by a complex interplay of multiple variables.

Comparative Evaluation of the Remineralizing Potential of Silver Diamine Fluoride, Casein Phosphopeptide-amorphous Calcium Phosphate, and Fluoride Varnish on the Enamel Surface of Primary and Permanent Teeth: An In Vitro Study.

Introduction: With the paradigm shift in the management of dental caries, the focus is now laid on remineralization therapies that can arrest the progression of the disease and remineralize the subsurface lesions. Objectives: The purpose of this study was to determine and compare the remineralizing potential of silver diamine fluoride (SDF), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and fluoride varnish (FV) on enamel surfaces in primary and permanent teeth. Materials and methods: A total of 120 primary anterior teeth and 120 premolars were used to prepare enamel blocks in acrylic resin. The mean baseline surface microhardness (SMH) for each sample was determined using a microvickers hardness testing machine. Thereafter, the samples were randomly and equally distributed into groups and subgroups based on the materials used, that is, SDF, CPP-ACP, FV, and distilled water (control). After subjecting the samples to a pH cycling regime, SMH was determined again and the percentage change in SMH was calculated. Results: The data were tabulated and subjected to statistical analysis using an independent t-test and one-way analysis of variance (ANOVA). In primary teeth, the least mean percentage reduction in SMH was observed after the application of FV followed by SDF, CPP-ACP, and control. In permanent teeth, both SDF and FV showed the least percentage reduction of enamel SMH followed by CPP-ACP and control. Conclusion: Silver diamine fluoride (SDF), FV, and CPP-ACP showed remineralizing potential in both primary and permanent teeth. How to cite this article: Kaur S, Bhola M, Bajaj N, et al. Comparative Evaluation of the Remineralizing Potential of Silver Diamine Fluoride, Casein Phosphopeptide-amorphous Calcium Phosphate, and Fluoride Varnish on the Enamel Surface of Primary and Permanent Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-1):S91-S96.

Effect of Adding Silver-Doped Carbon Nanotube Fillers to Heat-Cured Acrylic Denture Base on Impact Strength, Microhardness, and Antimicrobial Activity: A Preliminary Study.

Poly (methyl methacrylate) (PMMA), is an acrylic polymer substance that is mostly used for denture base applications. The purpose of this laboratory study was to investigate the effect of adding 0.05 wt.% Ag-doped carbon nanotubes (CNT) to PMMA-based (PMMA and MMA) denture base material on the impact strength, microhardness, and antimicrobial activity. A total of 60 heat-cured acrylic resin specimens were prepared. The specimens were randomly divided into two main groups (n = 30/group), according to the powder used: (a) control group, using heat-cured PMMA; (b) treatment group, using a powder prepared by blending 0.05 wt.% silver-doped CNT nanoparticles with heat-cured PMMA. The impact strength, microhardness and anticandidal activity for each group were assessed via the Charpy, Vickers and agar diffusion tests, respectively (n = 10/test for each subgroup). Data were analyzed using independent-sample t-tests (p ≤ 0.05). The results of the impact strength test revealed that the treated heat-cured PMMA-MMA with Ag-doped CNT (2.2 kJ/mm2) was significantly higher than that of the control heat-cured PMMA (1.6 kJ/mm2). Similarly, the Vickers microhardness of the treatment group (52.7 VHN) was significantly higher than that of the control group (19.4 VHN). Regarding the agar diffusion test, after 24 h of incubation, the treated heat-cured PMMA with the Ag-doped CNT exhibited significantly higher anticandidal activity than that of the control group. Therefore, Ag-doped carbon nanotubes could be considered as promising fillers for the dental heat-cured acrylic resin to improve the resistance of the resultant denture against sudden fractures, scratching, and candida invasion.

The effect of ascorbic acid and cranberry on the bond strength, surface roughness, and surface hardness of bleached enamel with hydrogen peroxide and zinc phthalocyanine activated by photodynamic therapy.

AIM: To evaluate the effect of different bleaching methods 40% (hydrogen peroxide) HP and Zinc Phthalocyanine (ZP) activated by photodynamic therapy (PDT) with the utilization of diverse procedures of reversal (10% ascorbic acid and 6% cranberry solution) on bond values, surface microhardness and surface roughness of bleached enamel surface. MATERIAL AND METHODS: An aggregate of 60 extracted human mandibular molars was gathered and the buccal surface of each specimen was exposed to 2 mm of enamel surface for bleaching with chemical and photoactivated agents with the use of reversal solutions. Specimens were divided into six groups (n = 10) at random- Group 1: samples bleached with 40% HP with 10% ascorbic acid (reversal agent), group 2: ZP activated by PDT with 10% ascorbic acid (reversal agent), group 3: 40% HP with 6% cranberry solution as a reversal agent, group 4: ZP activated by PDT with 6% cranberry solution, group 5: 40% HP and group 6: ZP activated by PDT with no reversal agents. Resin cement restoration was performed via etch and rinse technique and SBS was estimated by using the universal testing machine, SMH by using Vickers hardness tester, and Ra by stylus profilometer. Statistical analysis was executed using the ANOVA test and the Tukey multiple tests (p<0.05). RESULTS: Enamel surface bleached with 40% HP reversed with 10% ascorbic acid displayed the highest SBS while 40% HP with no reversal agent use showed the least SBS. For SMH, ZP activated by PDT when applied on the enamel surface and reversed with 10% ascorbic acid showed the highest SMH while when bleached with 40% HP and reversed with 6% cranberry solution showed the least SMH value. For Ra, Group 3: samples bleached with 40% HP with 6% cranberry solution as reversal agent showed the highest Ra value while bleaching of enamel surface with ZP activated by PDT with 6% cranberry displayed the least Ra value. CONCLUSION: Bleached enamel surface with Zinc Phthalocyanine activated by PDT with the application of 10% ascorbic acid as reversal solution has demonstrated the highest SBS and SMH with acceptable surface roughness for bonding adhesive resin to the enamel surface.

Neural network approach to evaluate the physical properties of dentin.

This study intended to evaluate the effects of inorganic trace elements such as magnesium (Mg), strontium (Sr), and zinc (Zn) on root canal dentin using an Artificial Neural Network (ANN). The authors obtained three hundred extracted human premolars from type II diabetic individuals and divided them into three groups according to the solutions used (Mg, Sr, or Zn). The authors subdivided the specimens for each experimental group into five subgroups according to the duration for which the authors soaked the teeth in the solution: 0 (control group), 1, 2, 5, and 10 min (n = 20). The authors then tested the specimens for root fracture resistance (RFR), surface microhardness (SµH), and tubular density (TD). The authors used the data obtained from half of the specimens in each subgroup (10 specimens) for the training of ANN. The authors then used the trained ANN to evaluate the remaining data. The authors analyzed the data by Kolmogorov-Smirnov, one-way ANOVA, post hoc Tukey, and linear regression analysis (P < 0.05). Treatment with Mg, Sr, and Zn significantly increased the values of RFR and SµH (P < 0.05), and decreased the values of TD in dentin specimens (P < 0.05). The authors did not notice any significant differences between evaluations by manual or ANN methods (P > 0.05). The authors concluded that Mg, Sr, and Zn may improve the RFR and SµH, and decrease the TD of root canal dentin in diabetic individuals. ANN may be used as a reliable method to evaluate the physical properties of dentin.

Surface Microhardness of Bulk-Fill Resin Composites Handled With Gloves.

AIM: It has been reported that resin composites may experience alterations in their mechanical properties when they come into contact with glove powder. Therefore, the present study aimed to compare the surface microhardness of 3 bulk-fill resin composites handled with latex and nitrile gloves prior to light curing. METHODS: This in vitro experimental study consisted of 90 resin composite specimens with a 6-mm diameter and a 4-mm height divided equally and randomly into 9 groups. Prior to light curing, the resin composites were handled with latex gloves, nitrile gloves, or only a spatula (control). Subsequently, the surface microhardness was measured with an Electronic Vickers Hardness Tester. The Kruskal-Wallis nonparametric H test with Bonferroni correction was used for comparisons. A significance level of 5% (P < .05) was considered. RESULTS: When comparing surface microhardness of each resin composite according to type of handling received, significant differences were observed in Filtek One Bulk Fill (P < .001) and Opus Bulk Fill (P < .001). In addition, these resin composites presented significantly higher surface microhardness than Tetric N-Ceram Bulk Fill resin (P < .05) when handled with latex gloves, nitrile gloves, and only a spatula. Finally, Filtek Bulk Fill resin presented significantly higher surface microhardness compared to Opus Bulk Fill resin when handled with nitrile gloves (P = .038) and a spatula only (P = .033). CONCLUSIONS: The surface microhardness of Filtek One Bulk Fill and Opus Bulk Fill resin composites decreased significantly when handled with latex or nitrile gloves, showing no variation in Tetric N-Ceram Bulk Fill resin composite. In addition, Filtek One Bulk Fill resin composite showed significantly higher surface microhardness than Opus Bulk Fill and Tetric N-Ceram Bulk Fill resin composites when handled with nitrile gloves. It is recommended that bulk-fill resin composites be handled with a spatula, because the use of latex or nitrile gloves could adversely affect their clinical performance.

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

BACKGROUND: In the preventive treatment protocol, providing remineralization of the tissue in demineralized dentin caries is an important step. OBJECTIVE: In this in vitro study, the effectiveness of remineralization agents in natural caries-affected dentin (NCAD) were investigated. METHODS: Forty caries slices were prepared from permanent molar dentin with International Caries Detection and Assessment System (ICDAS 2) (Code 3). 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. RESULTS: 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. CONCLUSION: 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.

Effect of sodium fluoride plus tricalcium phosphate with and without CO2 laser on remineralization of white spot lesions.

Objectives: The aim of this in vitro study was to evaluate the effect of NaF plus TCP with and without CO2 laser irradiation on management of demineralized enamel using microhardness test and digital microscopy. Methods: Eighty intact extracted human premolar teeth were randomly divided into 4 groups (20/each). Each group was subjected to a demineralizing solution to create white spot lesion. Group 1 was treated with 3M Vanish™. Group 2 was irradiated with CO2 laser. Group 3 was subjected to CO2 laser followed by 3M Vanish™. Group 4 was treated by 3M Vanish™ then CO2 laser. The teeth were immersed in artificial saliva. Surface microhardness was measured for each tooth before demineralization at base line (M1 as a control), after demineralization (M2) and after management (M3). Comparison of microhardness values between groups was performed using one way ANOVA test with significant level (0.05) followed by multiple comparisons post-hoc Tukey test between groups. Enamel surface was photographed by digital microscope. Results: All intervention methods used in the current study significantly increased microhardness values of demineralized enamel (P < 0.001). Little improvement of enamel appearance was observed in all groups meanwhile using CO2 laser on demineralized enamel directly led to signs of white and black dots affecting the appearance of enamel surface. Significance: The most effective intervention regarding microhardness was group 2 followed by group 3, group 4 and group 1. Coating the enamel surface with 3M Vanish™ before CO2 laser irradiation acted as a protective layer from the undesirable effects of laser on the teeth with increasing enamel microhardness values more than using Vanish alone. So the promising intervention method regarding both microhardness and appearance was group 4.

The Microhardness and Surface Roughness Assessment of Bulk-Fill Resin Composites Treated with and without the Application of an Oxygen-Inhibited Layer and a Polishing System: An In Vitro Study.

The aim of this study was to assess the microhardness and surface roughness of bulk-fill resin composites treated with and without the application of an oxygen-inhibited layer (OIL) and a polishing system. This in vitro experimental study consisted of 72 resin composite blocks divided into three groups: Tetric N-Ceram Bulk Fill, Opus Bulk Fill APS, and Filtek Bulk Fill. Each resin composite group was further divided into two subgroups: with and without OIL control. Subsequently, surface roughness and microhardness were measured before and after polishing. A t-test was used to compare independent and related measures. For the intergroup comparison of variation before and after polishing, the Kruskal−Wallis test with Bonferroni post hoc was used considering a significance level of p < 0.05. When comparing surface roughness, significant differences were observed between Opus Bulk Fill resin composite with and without OIL control (p = 0.003) before polishing. The same occurred when comparing Tetric N-Ceram resin composite with and without OIL control (p = 0.039) after polishing. In addition, the surface roughness of Filtek Bulk Fill, Opus Bulk Fill, and Tetric N-Ceram Bulk Fill resin composites, with and without OIL control, decreased significantly after polishing (p < 0.001), while surface microhardness significantly increased (p < 0.05), with the exception of Opus Bulk Fill resin with OIL control (p = 0.413). In conclusion, OIL control and polishing significantly improved the surface roughness and surface microhardness of Filtek Bulk Fill and Tetric N-Ceram Bulk Fill resin composites. However, in the case of Opus Bulk Fill resin composite, only its surface roughness was significantly improved.

Influence of periodic polyphenol treatment on the anti-erosive potential of the acquired enamel pellicle-A qualitative exploratory study.

OBJECTIVE: The aim of the present study was to investigate the impact of periodic polyphenol treatment on the ultrastructure and anti-erosive potential of an in-situ formed pellicle. METHODS: Subjects wore intraoral appliances with buccally and palatally fixed bovine enamel specimens. During 6 h of intraoral pellicle formation, 100 ml black tea or tannic acid was applied ex-vivo every 25 min for 5 min. Untreated pellicles served as control. After the trial, specimens were immersed in 0.1% or 1% citric acid for 60 s and analysed for calcium release with atomic adsorption spectrometry and ultrastructure with transmission electron microscopy. RESULTS: Specimens covered by pellicles treated with black tea or tannic acid released less calcium than untreated pellicles. Ultrastructural analyses reveal an increase in pellicle's thickness and density after treatment with polyphenols. CONCLUSIONS: Periodic polyphenol treatment of the pellicle modify its ultrastructure and increase its anti-erosive potential. CLINICAL SIGNIFICANCE: Consumption of polyphenolic beverages can enhance the anti-erosive potential of the enamel pellicle.

Evaluation of Remineralizing Potential of CPP-ACP, CPP-ACP + F and ß TCP + F and Their Effect on Microhardness of Enamel Using Vickers Microhardness Test: An In Vitro Study.

Context: The change in understanding of dental caries which is now believed to be a reversible lesion has led to the change in its management. Aim: To evaluate the remineralizing potential of three remineralizing agents [casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP), CPP-ACP + F, and beta-tricalcium phosphate (ß TCP) + F] and their effect on microhardness of enamel using Vickers microhardness test. Materials and method: Forty freshly extracted premolars, extracted for orthodontic purpose were collected and specimen prepared. The specimens were equally divided into four groups. Baseline surface microhardness measurement was taken for the specimens. Demineralization of enamel was carried out by keeping the specimens in 20 mL of demineralizing solution for 72 hours, and microhardness was evaluated. Remineralizing agents CPP-ACP, CPP-ACP + F, and ß TCP + F was applied to Group A, Group B, and Group C, respectively for 28 days and microhardness was evaluated again. Group D was kept as control group. Statistical analysis was done by One-way ANOVA test. Percentage microhardness recovery was calculated to evaluate the regain in microhardness after remineralization and thus assess the remineralizing efficacy of the agents. Results: After demineralization surface microhardness of enamel decreased to the range of Vickers hardness number (VHN) 155-167 but after application of remineralizing agents surface microhardness for Group B was found to be highest, in other words, VHN 240.78 followed by Group C, in other words, VHN 214.29 and Group A the least VHN 197.90. Conclusion: The result of this study concludes that surface microhardness of enamel decreased after demineralization procedure and increased after application of all the remineralizing agents. The highest increase was seen in group tested with CPP-ACP + F followed by ß TCP and least for CPP-ACP. The values for all the three groups were higher than the control so we can conclude that all the agents can be used as remineralizing agent with CPP-ACP + F being the best among the three. How to cite this article: Bhat DV, Awchat KL, Singh P, et al. Evaluation of Remineralizing Potential of CPP-ACP, CPP-ACP + F and ß TCP + F and Their Effect on Microhardness of Enamel Using Vickers Microhardness Test: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(S-2):S221-S225.

Effects of Sr/F-Bioactive Glass Nanoparticles and Calcium Phosphate on Monomer Conversion, Biaxial Flexural Strength, Surface Microhardness, Mass/Volume Changes, and Color Stability of Dual-Cured Dental Composites for Core Build-Up Materials.

This study prepared composites for core build-up containing Sr/F bioactive glass nanoparticles (Sr/F-BGNPs) and monocalcium phosphate monohydrate (MCPM) to prevent dental caries. The effect of the additives on the physical/mechanical properties of the materials was examined. Dual-cured resin composites were prepared using dimethacrylate monomers with added Sr/F-BGNPs (5 or 10 wt%) and MCPM (3 or 6 wt%). The additives reduced the light-activated monomer conversion by ~10%, but their effect on the conversion upon self-curing was negligible. The conversions of light-curing or self-curing polymerization of the experimental materials were greater than that of the commercial material. The additives reduced biaxial flexural strength (191 to 155 MPa), modulus (4.4 to 3.3), and surface microhardness (53 to 45 VHN). These values were comparable to that of the commercial material or within the acceptable range of the standard. The changes in the experimental composites' mass and volume (~1%) were similar to that of the commercial comparison. The color change of the commercial material (1.0) was lower than that of the experimental composites (1.5-5.8). The addition of Sr/F-BGNPs and MCPM negatively affected the physical/mechanical properties of the composites, but the results were satisfactory except for color stability.

Compressive strength, surface roughness, and surface microhardness of principle tricalcium silicate-based endodontic cements after universal adhesive application.

Aims and Background: It was aimed to evaluate compressive strength (CS), surface roughness, and microhardness of mineral trioxide aggregate (ProRoot MTA) and Biodentine (BD) after adhesive application. Materials and Methods: Tests was carried out according to international ISO standard. ProRoot MTA and BD were prepared in Teflon molds according to manufacturer's instructions: n = 210 for CS; n = 210 for microhardness. Samples were incubated for 7 days at 37°C in 100% humidity. Surfaces were smoothed with up to 2000 grits of silicon-carbide sandpaper on abrasive device at 150 rpm, randomly divided into seven groups (n = 15). Clearfil Universal Bond, All Bond Universal, and Single Bond Universal (SBU) were applied in both total-etch and self-etch (SE) modes. Adhesives were applied according to manufacturers' recommendations (no adhesive used in control). CS was performed at speed of 1 mm/min, microhardness at 100 gr for 15 s. The surface roughness of the samples was analyzed with atomic force microscopy. Two-way analysis of variance and post hoc Tukey tests were used for the evaluation of the data. Results: Man CS and microhardness values between ProRoot MTA and BD were as follows: 24.9 N, 72.6 HV; 59.8 N, 59.0 HV, respectively. In CS, BD was higher than ProRoot MTA (P < 0.05). In other comparisons except for SBU SE group (P < 0.05), BD and ProRoot MTA showed similar results (P > 0.05). However, ProRoot MTA was found higher than BD regarding microhardness (P < 0.05). As a result of the adhesive application in both BD and ProRoot MTA groups, a decrease in surface roughness was observed compared to the control group. Conclusion: BD exhibited better results than ProRoot MTA regarding CS. However, ProRoot MTA was found to be more successful than BD in terms of microhardness. BD and ProRoot MTA showed similar physical properties in terms of surface roughness. To improve regenerative procedures, besides the selection of bioceramic cements, the interaction between cements and materials applied during coronal restoration should be considered.

An alkasite restorative material effectively remineralized artificial interproximal enamel caries in vitro.

OBJECTIVE: To evaluate the remineralization of artificial interproximal enamel caries (AIEC) adjacent to alkasite, high viscous glass ionomer cement (HVGIC), and resin composite in class II restorations. MATERIALS AND METHODS: Human enamel specimens were randomly assigned to 3 groups (n = 22): Filtek™ Z350, EQUIA Forte®, and Cention N®. The baseline hardness was determined using a Knoop microhardness assay. AIEC was formed in the specimens, and they were placed in contact with the proximal restorative materials then subjected to a 7-day pH cycling. Microhardness was determined post-artificial caries formation and post-pH cycling. The differences in the percentage of surface hardness recovery (%SHR) between the groups were compared using the Kruskal-Wallis test. The Dunn's test was used for between-group comparisons (p < 0.05). Specimen surface morphology was evaluated using scanning electron microscopy (SEM), and the calcium, phosphorus, and fluoride contents were analyzed by energy-dispersive spectroscopy (EDS). ANOVA with the post hoc Tukey multiple comparison test was used to evaluate the differences between groups (p < 0.05). RESULTS: The Cention N® %SHR was the highest, followed by EQUIA Forte®, and Filtek™ Z350. There was a significant difference in the %SHR between Cention N® and Filtek™ Z350 (p < 0.05). In contrast, there were no significant difference between Cention N® and EQUIA Forte®. Significantly increased enamel surface fluoride content was observed in the Cention N® compared with Filtek™ Z350 specimens (p < 0.05). The SEM image of the Cention N® specimens demonstrated the greatest mineral deposition. CONCLUSIONS: Cention N® markedly increased the surface hardness and fluoride content of adjacent AIEC compared with Filtek™ Z350 restorations. CLINICAL RELEVANCE: Cention N® is a promising alternative restorative material to remineralize initial enamel lesions in approximal adjacent surfaces, especially in high-risk caries patients.