Surface topography and spectrophotometric assessment of white spot lesions restored with nano-hydroxyapatite-containing universal adhesive resin: an in-vitro study

BACKGROUND

White spot lesion (WSL) is a main shortcoming accompanied by orthodontic treatment. It impairs the esthetic, surface hardness, and surface texture of enamel. So, this study was conducted to analyze the surface characteristics and color change of white spot lesions treated with nano-hydroxyapatite (nHA)-enriched universal adhesive resin.

MATERIALS AND METHODS

Eighty sound human permanent molars crowns were sectioned into two halves, producing 160 specimens. 16 specimens were left untreated, and 144 specimens were artificially-demineralized to generate WSLs. The specimens were classified according to the treatment approach applied as follows: I; Sound enamel, Group II; artificially-created WSLs, Group III; ICON resin-restored WSLs, Group IV; Universal adhesive resin-restored WSLs, Group V; 0.5 wt% nHA-containing universal adhesive resin-restored WSLs, Group VI; 1 wt% nHA-containing universal adhesive resin- restored WSLs, and Group VII; 3 wt% nHA-containing universal adhesive resin-restored WSLs, Group VIII; 5 wt% nHA-containing universal adhesive resin-restored WSLs, Group IX; 7 wt% nHA-containing universal adhesive resin-restored WSLs, and Group X; 10 wt% nHA-containing universal adhesive resin-restored WSLs. Some surface characteristics and color changes were assessed. Data was collected and analyzed statistically using ANOVA and the Tukey test at p < 0.05.

RESULTS

Surface microhardness of WSLs was significantly improved with all investigated ratios of nHA-containing universal adhesive (p < 0.0001), with the highest mean belonging to 10 wt% nHA-containing universal adhesive resin treated WSLs. All ratios of nHA-containing universal adhesive resin significantly reduced the surface roughness of WSLs (p < 0.0001). The investigated ratios of 1, 3, 5, 7, and 10 wt% nHA-containing universal adhesive resin treatment approach could mask the WSLs significantly (p < 0.0001).

CONCLUSIONS

Nano-hydroxyapatite-containing universal adhesive is a promising contemporary approach for the management of WSLs, coupled both the remineralizing concept and the minimally invasive resin infiltration.

Casein phosphopeptide amorphous calcium phosphate and universal adhesive resin as a complementary approach for management of white spot lesions: an in-vitro study

Background

White spot lesion (WSL) is the most common consequence during and after orthodontic treatment. This study was conducted to investigate the ability of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) coupled with universal adhesive resin to treat white spot lesions.

Material and methods

Forty-five extracted premolars were sectioned to create 90 specimens. Seventy-five specimens were demineralized to generate artificially created WSLs. Different strategies have been applied for the management of the artificially created WSLs. Six experimental groups were employed: Group I: sound enamel (control), Group II: demineralized enamel (artificially-created WSLs), Group III: ICON resin-treated WSLs, Group IV: CPP-ACP-treated WSLs, Group V: universal adhesive resin-treated WSLs, and Group VI: CPP-ACP followed by universal adhesive resin-treated WSLs. Assessment of color stability using a spectrophotometer, surface microhardness using a Vickers tester, and surface roughness using a profilometer was done. The surface topography of representative specimens from each experimental group was inspected using a scanning electron microscope. Collected data were analyzed using one-way ANOVA followed by Tukey’s post hoc test at p ≤ 0.05.

Results

White spot lesions treated with CPP-ACP and subsequently coated with universal adhesive resin (Group VI) exhibited a significantly lower ΔE than both CPP-ACP (Group IV) and universal adhesive resin-treated (Group V) groups (p ≤ 0.05), but it was not significantly different from the ICON resin-treated group (Group III). For surface microhardness, WSLs treated with CPP-ACP and consequently coated with universal adhesive resin (Group VI) recorded the highest mean that was significantly different from both ICON resin (Group III) and universal adhesive resin-treated (Group V) groups (p ≤ 0.05). All the tested strategies (ICON resin, CPP-ACP, universal adhesive resin, and CPP-ACP followed by universal adhesive resin) significantly lowered the surface roughness of the WSLs (p ≤ 0.05), while no significant difference was detected among them.

Conclusions

Combining a considerable caries remineralizing program using CPP-ACP with subsequent universal adhesive resin infiltration could be a promising approach to manage WSLs efficiently through increasing surface microhardness and restoring esthetic while developing a smoother surface.

Evaluation of Mechanical Properties and Antibacterial Activity of Nano Titania-Enriched Alkasite Restorative Material: An In Vitro Study

Background:

A biocompatible additive with the ability to establish antibacterial action for restorative materials without sacrificing their physical properties is always in demand. Nano titania (TiO2 nanoparticles) was shown to have antimicrobial action against a wide range of microorganisms. Alkasite is a modern esthetic restorative material that has outstanding properties; however, it is deficient in antibacterial activity.

Objective:

TiO2 nanoparticles (NPs) were included in alkasite, and both mechanical properties and antibacterial activity of the new formulations were assessed.

Materials and Methods:

Nano titania powder was coupled to alkasite powder in proportions of 3 and 5% (w/w). There were 105 specimens made in total. Evaluation parameters were compressive strength, surface microhardness, surface roughness, water sorption and solubility, and antibacterial activity. One and two-way ANOVA were used for the statistical analysis, followed by Tukey′s test (p<0.05).

Results:

Both ratios of nano titania, 3 and 5% (w/w), significantly increased compressive strength, antibacterial activity against different pathogens, and decreased water solubility of alkasite (p<0.05). Only 5% (w/w) nano titania-modified alkasite exhibited significant decrease in water sorption (p<0.05). Conversely, an insignificant increase in microhardness and surface roughness was observed with both ratios, 3 and 5% (w/w) of nano titania (p˃0.05).

Conclusion:

Nano titania seems to be a very promising complementary additive to the alkasite restorative material, capable of generating considerable antibacterial effectiveness while also enhancing certain mechanical properties.

An In Vitro Assessment of Surface Roughness, Tensile Bond Strength and Antifungal Activity of Grape Seed Extract-modified Soft Liner

AIM

This study was conducted to evaluate the grape seed extract (GSE)-modified soft liner regarding surface roughness, tensile bond strength to the denture base material, and the antifungal activity.

MATERIALS AND METHODS

The GSE powder was blended with the soft liner powder in ratios of 5 and 10% w/w, and three groups were employed: I, control; II, 5% w/w GSE-modified soft liner; III, 10% w/w GSE-modified soft liner. Evaluation parameters included surface roughness, tensile bond strength to the denture base material, and the antifungal activity. Changes in surface topography were evaluated by scanning electron microscopy. The statistical analysis was performed using the one-way ANOVA followed by the Tukey's test (α = 0.05).

RESULTS

The 5% w/w GSE-modified soft liner showed a significant increase in surface roughness, while both ratios (5 and 10% w/w) of the modified-soft liner exhibited significant increase in tensile bond strength and antifungal activity (p < 0.05).

CONCLUSION

The GSE of 10% w/w considerably enhanced the antifungal activity and tensile bond strength of the modified soft liner to the denture base material without compromising its surface roughness.

CLINICAL SIGNIFICANCE

The 10% w/w GSE-modified soft liner may be a promising formulation with antifungal activity. It could inhibit fungal adherence and development of fungi-induced lesions or exacerbation of existing ones.

Electro-chemical deposition of nano hydroxyapatite-zinc coating on titanium metal substrate

BACKGROUND

Titanium is an inert metal that does not induce osteogenesis and has no antibacterial properties; it is proposed that hydroxyapatite coating can enhance its bioactivity, while zinc can contribute to antibacterial properties and improve osseointegration.

AIMS

A nano-sized hydroxyapatite-zinc coating was deposited on commercially pure titanium using an electro-chemical process, in order to increase its surface roughness and enhance adhesion properties.

METHODS

The hydroxyapatite-zinc coating was attained using an electro-chemical deposition in a solution composed of a naturally derived calcium carbonate, di-ammonium hydrogen phosphate, with a pure zinc metal as the anode and titanium as the cathode. The applied voltage was -2.5 for 2 h at a temperature of 85 °C. The resultant coating was characterized for its surface morphology and chemical composition using a scanning electron microscope (SEM), energy dispersive x-ray spectroscope (EDS), and Fourier transform infrared (FT-IR) spectrometer. The coated specimens were also evaluated for their surface roughness and adhesion quality.

RESULTS

Hydroxyapatite-zinc coating had shown rosette-shaped, homogenous structure with nano-size distribution, as confirmed by SEM analysis. FT-IR and EDS proved that coatings are composed of hydroxyapatite (HA) and zinc. The surface roughness assessment revealed that the coating procedure had significantly increased average roughness (Ra) than the control, while the adhesive tape test demonstrated a high-quality adhesive coat with no laceration on tape removal.

CONCLUSIONS

The developed in vitro electro-chemical method can be employed for the deposition of an even thickness of nano HA-Zn adhered coatings on titanium substrate and increases its surface roughness significantly.