New Pre-reacted Glass Containing Dental Composites (giomers) with Improved Fluoride Release and Biocompatibility

Elemental analysis and micromorphological patterns of tooth/restoration interface of three ion-releasing class V restorations

OBJECTIVES

To evaluate and compare the ion-releasing capability of three different restorative systems at the restoration/tooth interface elemental analysis using energy-dispersive X-ray technique. Additionally, micromorphological patterns of the restoration/tooth interfaces was investigated.

MATERIALS AND METHODS

Eighteen freshly extracted sound human premolars were collected for the study. The premolars were randomly assigned into 3 groups (n = 6) based on the type of restorative materials used: Giomer (Beautifill II), ion-releasing composite (Activa Presto), and RMGI (Riva Light Cure). Half of the specimens in each group were tested after 24 h (the "immediate group"), while the remaining half were tested after 6 months of storage in deionized water (the "delayed group"). Standardized box-shaped cavities along the cervical area of teeth crowns and restored them with the assigned restorative material following manufacturers' instructions. The specimens were sectioned buccolingually into 2 halves. One half of each specimen was subjected to elemental analysis using energy-dispersive X-ray technique (EDX), while the remaining half was sputter coated and underwent micromorphological analysis of the restoration/tooth interface using a scanning electron microscope (SEM). The collected data from elemental analysis test were tabulated and subjected to statistical analysis.

RESULTS

The two-way ANOVA test showed significant differences in both phosphorus and calcium levels among the tested restorative systems (p < 0.05). In the immediate subgroup, RMGI recorded the highest phosphorus level (0.1527), followed by the ion-releasing composite (0.1172), while Giomer exhibited the least levels (0.0326) (p < 0.05). The ion-releasing composite group had the highest calcium level (0.2797), followed by RMGI (0.248), and Giomer (0.2385) respectively (p < 0.05). In the delayed subgroups, Giomer recorded the highest phosphorus level (0.1526), followed by the ion-releasing composite (0.1058), and RMGI group (0.0466) respectively (p < 0.05). RMGI had the highest calcium level (0.2801), followed by the ion-releasing composite (0.2659), and Giomer had the lowest level (0.1792) (p < 0.05). The micromorphological analysis of the restoration/tooth interfaces showed good adaptation between the composite and tooth substrate in different restorative groups.

CONCLUSIONS

The ion-releasing capability of the three restorative systems appears to be comparable. The rate of mineral release and diffusion is affected by time and composition.

Effect of Radiotherapy on the Adhesive Interface of Caries-affected Dentin and Bioactive Restorations: A Micro-CT Analysis

PURPOSE

This study aimed to analyze the presence of defects within the adhesive interface formed with five bioactive dental materials and caries-affected dentin concerning the timing of radiotherapy (before or after the restorative procedures) by micro-CT.

METHODS AND MATERIALS

A total of 96 carious human molars were randomly allocated into the following groups based on the timing of the radiotherapy sequence: radiotherapy followed by restoration (RT1) or restoration followed by radiotherapy (RT2). Then, six subgroups were established within these groups based on the type of materials used (n=8). Following cavity preparation and caries removal, a universal adhesive (G-Premio Bond) was administered in self-etch mode or accompanied by applying suitable cavity conditioners according to the manufacturers' guidelines. Subsequently, restorations were performed using five bioactive restorative materials (resin-modified glass-ionomer [Fuji II LC], high-viscosity glass-ionomer hybrid [EQUIA Forte HT], giomer [Beautifil II], alkasite [Cention N], and dual-cure bulk-fill composite [Activa Bioactive Restorative]) and a conventional microhybrid resin composite (Filtek Z250). The radiotherapy regimen encompassed 60 Grays (Gy) administered at a rate of 2 Gy/day over 6 weeks, 5 days a week. Micro-CT analysis was employed to assess adhesive defects at the interface between caries-affected dentin and the restorations. The data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Dunn tests (α=0.05).

RESULTS

RT2 caused significantly higher adhesive defects than RT1 for the Filtek Z250 and Activa Bioactive Restorative subgroups (p<0.05). For RT1, no significant differences were found in adhesive defects among all tested subgroups (p>0.05). By contrast, for RT2, adhesive defects were significantly higher for the Activa Bioactive Restorative and Cention N subgroups than for the EQUIA Forte HT and Beautifil II subgroups (p<0.05).

CONCLUSIONS

When using most bioactive restorative materials, the timing of radiotherapy had no significant influence on the adhesive interface. Regarding restoration following a radiotherapy protocol, a favorable impact was identified with high-viscosity glass ionomer hybrid cement and giomer bioactive restorations compared with dual-cure bioactive bulk-fill composite and alkasite restorations.

Effect of a demineralization model on the microhardness, surface roughness and topography of giomers: An in vitro study

The purpose of this study is to compare the effect of a demineralization model on the microhardness, surface roughness, and topography of giomers.Seventy-two discs of six different dental materials in three different presentations (pit and fissure sealant (PFS), flowable and restorative materials) were divided into six groups (n = 12 p/g). Three experimental groups (giomers) consisted of BeautiSealant, Beautifil Flow Plus, and Beautifil II, and three control groups (resin-based materials) were formed using ClinproTM, FiltekTM Z350 XT Flow, and Filtek™ Bulk Fill materials. Vickers microhardness, surface roughness, and topographic analysis with atomic force microscopy were measured at the beginning (0) after four (1) and 7 days (2) of immersion in a demineralizing model. Statistical analysis was performed using One-way and Repeated Measures ANOVA and Pearson's correlation coefficient (p ≤ .05). The microhardness values showed significant variations, except for the G_RM group. All the groups presented significant increases in roughness through the experiment stages, except for RB_PFS in the Ra parameter. The topographic analysis showed variations in the micromorphology, especially in the experimental group at the end of the demineralization model. Finally, there was no correlation between microhardness and surface roughness. The demineralization model decreased the microhardness, with the lowest reductions in the giomers groups. The effect of the demineralizing model on the surface roughness and topography showed an increase in specific patterns for the experimental and control groups. Therefore, their clinical use is recommended. RESEARCH HIGHLIGHTS: The demineralization model decreased the microhardness property of the evaluated materials, with better performance for the giomer groups. The effect of the demineralizing model on surface roughness showed an increase with specific patterns for the experimental and control groups. Although the materials presented changes in their microhardness, roughness, and topography, their clinical use is recommended.

Evaluation of Abfraction Lesions Restored with Three Dental Materials: A Comparative Study

BACKGROUND

Abfraction lesions are manifested as damage to hard tissues in the cervical area of dental crowns. The study aimed to assess the direct restoration of abfraction lesions according to the modified United States Public Health Service (USPHS) criteria for 24 months. The restorations were accomplished with Fuji Bulk-GC, Omnichroma Flow-Tokuyama, and Beautifil® II-Shofu dental materials, and the therapy was or was not associated with wearing thermoformed mouthguards.

METHODS

From the 53 selected and analyzed patients (n = 53), 28 patients (with restorations of abfraction lesions) belonged to the 1st group and 25 patients (with 105 restorations, who also wore mouthguards) belonged to the 2nd group. Blind determination assessments were effectuated at baseline and after 2, 6, 12, 18, and 24 months. Results showed that, regardless of the rating score, there are no significant statistical differences in the evaluation criteria between the two groups of patients Conclusions: For each material, the scores of USPHS criterion presented good clinical performances after 24 months, with no significant statistical differences between the fillings and the applied therapy in the two groups of patients.

Effect of laser bleaching, ultrasonic scaling and powered tooth brushing on surface roughness and bacterial adherence of class V composite restorations

Objective

To evaluate and compare the effect of diode laser assisted bleaching, ultrasonic scaling and powered tooth brushing on surface roughness and bacterial adherence on class V cavities restored with composites.

Materials and methods

A total of one hundred and twenty samples (40 samples each of Brilliant Everglow, Beautifil II and Heytec-N) were prepared in standardized stainless steel molds. The samples were further subdivided into four subgroups i.e. one control group (without any intervention) and three experimental groups - diode laser assisted bleaching, ultrasonic scaling and powered tooth brushing consisting of 10 sample each. Surface roughness was measured quantitatively with the help of 3D Optical Profilometer. For bacterial adherence analysis S. mutans strain (ATCC 25175) was cultured in BHI medium and samples were evaluated for the presence of viable bacteria using the Colony Forming Unit (CFU) count. Results obtained were then tabulated and subjected to statistical analysis.

Results

Diode laser bleaching caused a significant increase in surface roughness and bacterial adherence with lowest mean change exhibited by Heytec-N followed by Beautifil II and highest by Brilliant Everglow group. Similarly, Ultrasonic scaling increased the surface roughness of all the three tested samples with significant difference between the groups. Powered tooth brushing had no effect on the surface roughness and bacterial adherence of the tested composites.

Conclusion

Diode assisted laser bleaching and ultrasonic caused significantly higher surface roughness and bacterial adherence values for all the tested composites. It may therefore be recommended to do finishing and polishing of restorations after such procedures.

One-year follow-up of microscopical and clinical behavior of bioactive self-etching resin sealant

Background

The development of early carious lesions can be prevented with the use of sealants. This study aimed to evaluate the retention and sealant quality of conventional and bioactive self-etching sealants by direct (clinical) and indirect (microscopical) assessment.

Materials and Methods

Sixty newly erupted mandibular second molars (International Caries Detection and Assessment System ≤2) from adolescents were selected for the split-mouth trial study. The tooth was randomized and treated with conventional Fluoroshield (FS) and BeautiSealant (BS) bioactive self-etching sealants. Molds were taken and cast with epoxy resin after treatment. Indirect and direct assessments of retention degree and sealant remnant quality were performed after baseline, 1 month, and 1 year. The Chi-square test, ordinal regression, reasons of chance, and Fleiss' kappa statistical test were employed.

Results

After 1 month, greater total retention was observed for FS, but 1-year follow-up demonstrated no retention difference for FS and BS. The odds ratios showed an 86% greater chance of FS showing better marginal adaptation, after 1 month. At 1 year, the clinical assessment showed better anatomical shape and marginal adaptation scores for FS, but no microscopical difference was observed. A pour agreement between clinical and microscopical data was observed.

Conclusions

The 1-year follow-up showed no significant difference in the degree of retention, and in the microscopic evaluation of the conventional sealant (FS) and the bioactive self-etching sealant (BS), but in the clinical evaluation, better marginal and anatomical adaptation scores for FS were observed.

Clinical Evaluation of Low-shrinkage Bioactive Material Giomer Versus Nanohybrid Resin Composite Restorations: A Two-year Prospective Controlled Clinical Trial

This study evaluated the clinical performance of low-shrinkage bioactive resin composite compared with a conventional nanohybrid resin composite. A total of 35 patients (18 males, 17 females; mean age: 29±9 years old) received, randomly, 35 pairs of fillings restored with either low-shrinkage bioactive material employing Giomer filler technology (Beautifil II LS, Shofu Inc, Kyoto, Japan) or conventional nanohybrid resin composite (Clearfil Majesty Posterior, Kuraray, Japan) in Class I and Class II cavities. Two operators made all the restorations using the corresponding adhesive resins: FL-Bond II (Shofu Inc) and Clearfil SE Bond (Kuraray), according to each manufacturer's instructions. Two calibrated operators evaluated the restorations two weeks after placement (baseline), at six months, and at one and two years using FDI criteria (Scores 1-5). Data were analyzed using the McNemar test (α=0.05). Mean observation time was 27.4 ± 4.1 months (min=20.8; max=33.7). In both groups, according to FDI criteria, the restorations were mostly rated with best scores (Score 1 or 2) for biological, functional, and optical parameters. For one filling in the group restored with nanohybrid resin composite, a small and localized secondary caries lesion was observed and monitored at the one- and two-year follow-ups. One restoration in the low-shrinkage Giomer restorative group was accepted as a failure due to retention loss. Over the two-year follow-up, both the Giomer and the nanohybrid resin composite restorations' performance was clinically acceptable.

Biological and Physicochemical Characterization of Self-Adhesive Protective Coating Dental Restorative Material after Incorporation of Antibacterial Nanoparticles

This study evaluated the physicochemical and antibacterial properties of EQUIATM coat liquid (E) after incorporation of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles. ZnO and TiO2 (1 wt.% and 2 wt.%) were dispersed in EQUIA coat. Principal component analysis (PCA) and cluster analysis were performed to visualize systemic variation. Antibacterial activity was evaluated by colony-forming units and crystal violet staining using Streptococcusmutans and Lactobacillusacidophilus after 24 h, 48 h, and 72 h, and the microstructure was studied by scanning electron microscopy. The weight change was analyzed at 1 and 21 days. The PCA for TiO2- and ZnO-based groups showed 100% variance at all spectral ranges at 600−800/cm and 800−1200/cm, whereas 1200−1800/cm and 2700−3800/cm spectral regions demonstrated 99% variance. The absorbance values were significant (p < 0.05) for both nanoparticles-based adhesives, and the specimens with 2 wt.% ZnO showed the maximum response by minimum bacterial attachment, and the control group showed the least response by maximum attachment. The weight change percentage was reduced after the incorporation of antibacterial nanoparticles. It is suggested that EQUIATM coat containing nanoparticles exhibits promising results, and it may be recommended to clinically use as an improved coating material.

Five-year clinical performance of two fluoride-releasing giomer resin materials in occlusal restorations

OBJECTIVE

To evaluate and compare the clinical performance of two nano-hybrid giomer restorative composite materials after 5 years.

MATERIALS AND METHODS

Forty-four pairs of restorations (total n = 88) of a flowable giomer (Beautifil Flow Plus F00; Shofu Inc., Kyoto, Japan) and a conventional nano-hybrid giomer restorative material (Beautifil II; Shofu Inc.) were placed in Class I cavities after the application of a dentin adhesive (FL-Bond II; Shofu Inc.) and a flowable liner (Beautifil Flow Plus F03; Shofu Inc). After 5 years, 32 pairs of restorations were assessed using the modified United States Public Health Service criteria. Both tested materials were compared using Fisher's exact test and each tested clinical criterion for each material was analyzed separately with respect to different follow-up periods using Friedman's test (a = 0.05).

RESULTS

None of the restorations showed complete retention loss, post-operative sensitivity, secondary caries or color change. There were no significant changes to any of the clinical criteria for each material during the 5-year evaluation period (p > 0.05) and no significant differences between the two materials in all clinical parameters after 5 years (p > 0.05).

CONCLUSIONS

Five-year clinical performance of both two nano-hybrid giomer restorative materials was comparably acceptable and not significantly different for any of the parameters evaluated.

CLINICAL SIGNIFICANCE

Nano-hybrid giomer-based materials are clinically acceptable for the restoration of occlusal cavities as they demonstrate excellent performance after 5 years.

Expert consensus on early childhood caries management

Early childhood caries (ECC) is a significant chronic disease of childhood and a rising public health burden worldwide. ECC may cause a higher risk of new caries lesions in both primary and permanent dentition, affecting lifelong oral health. The occurrence of ECC has been closely related to the core microbiome change in the oral cavity, which may be influenced by diet habits, oral health management, fluoride use, and dental manipulations. So, it is essential to improve parental oral health and awareness of health care, to establish a dental home at the early stage of childhood, and make an individualized caries management plan. Dental interventions according to the minimally invasive concept should be carried out to treat dental caries. This expert consensus mainly discusses the etiology of ECC, caries-risk assessment of children, prevention and treatment plan of ECC, aiming to achieve lifelong oral health.

The Cytotoxicity of Dental Restorative Materials on Gingival Stromal Mesenchymal Cells-an In Vitro Study

BACKGROUND

Due to their minimally invasive high-quality adhesive, aesthetic and mechanical qualities, composite resins are the most frequently used materials in modern restorative dentistry. However, polymerization shrinkage and cytotoxicity are still unresolved drawbacks associated with these biomaterials.

PURPOSE

The present study aimed to assess the cytotoxicity of some restorative resin-based materials on gingival mesenchymal stromal cells (gMSCs), assuming that no differences in their behavior will be highlighted.

MATERIAL AND METHODS

The cytotoxicity of the tested materials was evaluated by comparing the behavior of gMSCs cultured in normal conditions and in association with disc-shaped material samples indirectly through functionality tests (colony-forming unit-fibroblast assay, migratory potential) and directly through the MTT assay. The results were statistically analyzed with the ANOVA test and Tukey's Honest Significant Difference test.

RESULTS

According to the MTT assay, there are no statistically significant differences regarding the viability of gMSCs cultured in normal conditions or in the presence of resin-based material samples. On the other hand, the present study identified a significantly reduced number of colonies formed by the gMSCs cultured in association with BF and B discs, compared to that of gMSCs cultured in normal conditions. Also, the migratory potential was significantly lower for control gMSCs when compared to ZE-gMSCs and significantly higher for ZE-gMSCs when compared to BF-gMSCs or BFL-gMSCs.

CONCLUSIONS

The results of the present study highlight a possible risk of cytotoxicity when using resin based-materials in dental practice, but they cannot be directly extrapolated to in vivo situations.

Novel Giomers Incorporated with Antibacterial Quaternary Ammonium Monomers to Inhibit Secondary Caries

The objective of this study was to develop novel modified giomers by incorporating the antibacterial quaternary ammonium monomers (QAMs), dimethylaminododecyl methacrylate (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) into a commercial giomer. The material performances including mechanical properties, surface characteristics, color data, cytotoxicity and fluoride release of the novel giomers were evaluated. Antibacterial activity against severe early childhood caries (S-ECC) saliva-derived biofilms was assessed by lactic acid production measurement, MTT assay, biofilm staining and 16S rRNA sequencing. A rat model was developed and the anti-caries effect was investigated by micro-CT scanning and modified Keyes’ scoring. The results showed that the material properties of the QAMs groups were comparable to those of the control group. The novel giomers significantly inhibited lactic acid production and biofilm viability of S-ECC saliva-derived biofilms. Furthermore, caries-related genera such as Streptococcus and Lactobacillus reduced in QAMs groups, which showed their potential to change the microbial compositions. In the rat model, lesion depth, mineral loss and scoring of the QAMs groups were significantly reduced, without side effects on oral tissues. In conclusion, the novel giomers incorporated with antibacterial QAMs could inhibit the cariogenic biofilms and help prevent secondary caries, with great potential for future application in restorative treatment.

Development of New Experimental Dental Enamel Resin Infiltrants-Synthesis and Characterization

The aim of the present study was to obtain experimental infiltration materials, intended for the treatment of dental white spots, and to investigate them. Two series of infiltrants (P1–P6)/(P1F–P6F) were obtained, based on different monomer mixtures, without/with glass filler (with fluoride release ability). Each infiltrant from the second series contained the same amount of glass powder, and each infiltrant from the (P–PF) group contained the same resin composition. The characteristics of the experimental infiltrants were investigated by degree of conversion (DC), mechanical strength, water sorption (WS), and fluoride release, in addition to residual monomer for (P1F–P6F) infiltrants. The results were compared with those obtained for commercial Icon infiltrant. For the experimental infiltrants, without/with filler, the recorded DC was in the range of 58.27–89.70%/60.62–89.99%, compared with Icon (46.94%) 24 h after polymerization. The release of fluoride depends on the permeability of the polymer matrix, with respect to the water sorption, which may help to diffuse ions in the storage medium but which can also influence the release of residual monomers. The highest flexural strengths were recorded for the (TEGDMA/HEMA/Bis-GMA) infiltrants (133.94 ± 16.389 MPa/146.31 ± 7.032 MPa). The best experimental infiltrants were P2 and P2F (Bis-GMA/HEMA/TEGDMA).

Surface Characteristics, Fluoride Release and Bond Strength Evaluation of Four Orthodontic Adhesives

Orthodontic adhesives have similar properties in terms of fluoride release, roughness, shear bond strength or cement debris for specific clinical conditions. Three commercial consecrated orthodontic adhesives (Opal Seal^®, Blugloo^®, Light Bond^®) were compared with an experimental orthodontic material (C1). Brackets were bonded to enamel using a self-etch technique followed by adhesive application and then de-bonded 60 days later. Share bond strength evaluation, scanning electron microscopy, atomic force microscopy and fluoride release analysis were performed. The highest amount of daily and cumulative fluoride release was obtained for the experimental material, while the lowest value was observed for Opal Seal^®. The materials evaluated in the current study presented adequate shear bond strength, with the experimental material having a mean value higher than Opal Seal and Blugloo. The atomic force microscopy measurements indicated that the smoothest initial sample is Opal Seal^® followed by Light Bond^®. Scanning electron microscopy evaluation indicated different aspects of cement debris on the enamel and/or bracket surface, according to the type of adhesive. The experimental material C1 presented adequate properties in terms of shear bond strength, fluoride release, roughness and enamel characteristics after de-bonding, compared to the commercial materials. Under these circumstances, it can be considered for clinical testing.

Water Sorption and Solubility of Flowable Giomers

The objective of this study is the characterization of a novel experimental flowable giomer (G) regarding water sorption, water solubility, and the microstructural characteristics, in comparison to three commercial giomers: Beautifil flow Plus X F00 (B-F00), Beautifil flow F02 (B-F02) and Beautifil flow Plus X F03 (B-F03), Shofu, Kyoto, Japan. Methods: Water sorption/solubility was performed by weighing the specimens before and after water immersion for 1, 2, 3, 14, 21 and 30 days. Data analysis was carried out with the software Origin2019b Graphing & Analysis using the ANOVA test and the Tukey test for post hoc comparison of the groups of materials. The microstructural analyses were done with a scanning electron microscope (SEM) and an atomic force microscope (AFM). The results showed significant differences between the tested materials (p < 0.05). For sorption, the Tukey test indicated differences between all four sample groups, except between B-F02 and B-F03, which exhibited no differences in any of the investigation days. The Tukey test also showed significant differences regarding solubility between all sample groups in the 30-day interval. SEM images and roughness showed that after 30 days of immersion in water, the experimental giomer G had the roughest surface.

Fluoride-Releasing Restorative Materials: The Effect of a Resinous Coat on Ion Release

Objective

To determine the effect of two adhesive systems and a glass ionomer coating resin on fluoride release and concurrent pH changes over a period of 168 days.

Material and methods

Four restorative materials were investigated: a giomer Beautiful II, an “alkasite” material Cention, a conventional composite Filtek Z250, and a glass ionomer cement Fuji IX Extra. Light-cured composite specimens were coated using G-aenial Bond and Clearfil Universal Bond Quick. Glass ionomer specimens were coated using GC Fuji Coat LC. Uncoated specimens were used as references. Quantitative fluoride release and pH changes were measured after1 h, 24 h, 2 days, 7 days, 28 days, 84 days, and 168 days.

Results

The cumulative fluoride release after 168 days increased for uncoated specimens in the following order: Filtek Z250 < Beautifil II < Cention < Fuji IX Extra. A comparatively lower fluoride release was measured for the composites coated with Clearfil Universal Bond Quick, with cumulative values after 168 days increasing in the following order: Filtek Z250 < Beautifil II < Cention. The composites coated with G-aenial Bond showed lower fluoride release compared to the uncoated specimens, with cumulative values increasing in the following order: Filtek Z250 < Beautifil II < Cention. The composites coated with G-aenial Bond showed pH values in the acidic range (4.4-5.7) after 1 h and 24 h.

Conclusion

Fluoride release varied among the investigated restorative materials and depended on the use of dental adhesives and coatings. The pH of all materials, coating types and time points varied.

Evaluation of F, Ca, and P release and microhardness of eleven ion-leaching restorative materials and the recharge efficacy using a new Ca/P containing fluoride varnish

OBJECTIVES

The objectives of this study were to evaluate fluoride (F), calcium (Ca), and phosphate (P) release of ion-leaching restorative materials (ILMs), their recharge efficacy with a Ca/P-containing F varnish, and relative microhardness.

METHODS

Thirteen groups of materials were investigated. Cylindrical-shaped specimens were fabricated. Deionised water or lactic-acid solution were used as the storage media. Solutions were changed after 1d, 4d, 7d, and 14d of ion release and at the same periods after recharge with MI Varnish (7 -h storage). F, Ca, and P measurements were accomplished using a fluoride-ion selective electrode, atomic absorption spectrometry, and colourimetric method by spectrophotometer, respectively. Relative Vickers hardness was proceeded with similar specimens used in the F assay (4 periods). SEM/EDS was additionally performed. Statistical analyses were calculated in each parameter (p < 0.05).

RESULT

Hardness of several ILMs immediately increased after recharge. After 28d, Ketac Universal [a high-viscosity glass-ionomer cement (HVGIC)] showed the highest hardness similar to the resin composite control. Although 2 HVGICs (Zirconomer and Equia Forte Fil) ranked as first and second for F release/re-release, some HVGICs had inferior or comparable F capacity to RMGICs (Fuji VIII and Fuji II LC) and a resin-based (RB) ILM (Cention N). Cention N, Activa-Restorative (RB-ILM), and Zirconomer were the top-3 ranking for Ca release/re-release. Activa-Restorative showed the highest P release, whereas Cention N displayed the greatest recharge ability for P.

CONCLUSIONS

Zirconomer showed a versatile performance for ion-release/re-release, especially for F. Cention N had excellent capacity in relation to Ca release and recharge ability of Ca/P.

CLINICAL SIGNIFICANCE

With the F varnish recharge protocol, Zirconomer, Equia Forte, and Fuji VIII seems to have an ability to inhibit initial caries initiation. Cention N is a promising resin-based material that could be an alternative for high caries risk patients due to the high Ca release/recharge with acceptable F release.

Corrosion Behavior and Biological Activity of Micro Arc Oxidation Coatings with Berberine on a Pure Magnesium Surface

Bone tissue repair materials can cause problems such as inflammation around the implant, slow bone regeneration, and poor repair quality. In order to solve these problems, a coating was prepared by ultrasonic micro-arc oxidation and self-assembly technology on a pure magnesium substrate. We studied the effect of berberine on the performance of the ultrasonic micro-arc oxidation/polylactic acid and glycolic acid copolymer/berberine (UMAO/PLGA/BR) coating. The chemical and morphological character of the coating was analyzed using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The corrosion properties were studied by potentiodynamic polarization and electrochemical impedance spectroscopy in a simulated body fluid. The cumulative release of drugs was tested by high-performance liquid chromatography. The results indicate that different amounts of BR can seal the corrosion channel to different extents. These coatings have a self-corrosion current density (Icorr) at least one order of magnitude lower than the UMAO coatings. When the BR content is 3.0 g/L, the self-corrosion current density of the UMAO/PLGA/BR coatings is the lowest (3.14 × 10−8 A/cm2) and the corrosion resistance is improved. UMAO/PLGA/BR coatings have excellent biological activity, which can effectively solve the clinical problem of rapid degradation of pure magnesium and easy infection.

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.