Phosphorus Effects of Mesoporous Bioactive Glass on Occlude Exposed Dentin

Sol-gel bioactive glass containing biomaterials for restorative dentistry: A review

OBJECTIVE

Bioactive glasses (BAGs) have been researched extensively for dentistry due to their favourable biocompatibility and hard tissue bonding ability. However, the specific application of BAGs produced through sol-gel synthesis in restorative dentistry has not been reviewed previously. This review provides a comprehensive account of the principles behind sol-gel derived BAGs and their investigation for dental tissue restoration materials.

METHODS

A search for in vitro and in vivo studies was performed using the databases Web of Science®, Medline®, Scopus® and Google Scholar®. Articles published over the past 20 years were selected and data on the BAG composition and morphology was extracted. Analysis of the effect of specific BAG additives on the properties of experimental dental materials was also performed.

RESULTS

A majority of BAG particles investigated were spheres ranging in size from 5 nm to ~650 µm. Sol-gel BAGs are mainly applied in the treatment of hypersensitive dentine and for pulp-dentine tissue engineering, while a handful have been used in target drug delivery. BAG fillers are promising additives that result in improved biological properties, antibacterial effects, hardness, acid buffering and remineralization. Unfortunately, some detrimental effects on optical properties have been observed with BAG addition. Additionally, in vivo data, investigations into radiopacity and standardization of test protocols are identified as areas for improvement and further studies.

SIGNIFICANCE

Future work should consider the pertinent issues raised in order to improve the quality of available data and expand knowledge in this area of dental biomaterials research and development.

Enhanced effect of nano-monetite hydrosol on dentin remineralization and tubule occlusion

OBJECTIVES

We aim to investigate the dentin tubule occlusion and remineralization potential of a novel nano-monetite hydrosol (nMH).

METHODS

First, nano-monetite hydrosol (nMH) was fabricated by homogeneous precipitation method. Then, the effectiveness of toothpaste with nMH on improving remineralization was evaluated by the measurement of tubule occluding ratio and acid-resistant stability compared with dentifrices comprising nano-hydroxyapatite hydrosol (nHH) and bioactive glass (BG). To explain this result, we studied the ions releasing and remineralization based on gelatin scaffold among nMH, nHH and BG. Finally, the cytotoxicity of these three minerals on Human dental pulp stem cells (HDPSCs) was evaluated.

RESULTS

Processing for more than 7 days, the toothpaste containing nMH exhibited the significant remineralization potential and acid-resistant compared with two commercial de-sensitive dentifrices comprising nHH and BG. In addition, cytotoxicity test resulted that nMH has good cell compatibility to HDPSCs below extracts concentration of 3.12mg/mL.

SIGNIFICANCE

Small size, the release of Ca²⁺ and PO₄^3- with high concentration, strongly binding on dental surface, and fast transformation to HAp, were all needed in the preparation of effective dentin tubule occluding biomaterials.

Mesoporous Bioactive Glass Combined with Graphene Oxide Quantum Dot as a New Material for a New Treatment Option for Dentin Hypersensitivity

Dentin hypersensitivity is one of the most common clinical conditions usually associated with exposed dentinal tubules. The purpose of this study was to identify the potential of a graphene oxide quantum dot coating for mesoporous bioactive glass nanoparticles as a new material for the treatment of dentin hypersensitivity by investigating its mineralization activity and dentinal tubules sealing. Mesoporous bioactive glass nanoparticle was fabricated by modified sol-gel synthesis. X-ray diffraction was performed to characterize the synthesized nanoparticle Fourier transform infra-red spectroscopy investigated the functionalized surfaces. The distribution of the specific surface area and the pore size was measure by Pore size analysis. The morphology of sample was observed by Field Emission Scanning Electron Microscope (FESEM) and Field Emission Transmission Electron Microscope (FETEM). After disk-shaped specimens of mesoporous bioactive glass nanoparticles and graphene oxide quantum dot coated mesoporous bioactive glass nanoparticles (n = 3) were soaked in the simulated body fluid for 0, 1, 5, 10,and 30 days, the amount of ions released was observed to confirm the ionic elution for mineralization. Sensitive tooth model discs (n = 20) were applied with two samples and evaluated the dentinal tubule sealing ability. The spherical mesoporous bioactive glass nanoparticles and graphene oxide quantum dot coated mesoporous bioactive glass nanoparticles with a diameter of about 500 nm were identified through FESEM and FETEM. The ion release capacity of both samples appeared to be very similar. The amount of ion released and in vitro mineralization tests confirmed that graphene oxide quantum dot coating of mesoporous bioactive glass nanoparticles did not inhibit the release of calcium, silicon and phosphate ions, but rather that graphene oxide quantum dot promoted hydroxyapatite formation. In the FESEM image of the sensitive tooth disc surface, it was observed that graphene oxide quantum dot coated mesoporous bioactive glass nanoparticles sealed tightly the dentinal tubules. The graphene oxide quantum dot coating of mesoporous bioactive glass nanoparticles not only showed the excellent dentinal sealing ability but also rapidly promoted mineralization while minimizing the size increase by coating the mesoporous bioactive glass nanoparticles.

Avaliação ex vivoda obliteração de túbulos dentinários humanos pelo uso comparativo de agentes dessensibilizantes convencionais e dessensibilizantes contendo biovidro

O objetivo do presente estudo foi avaliar a eficácia ex vivo de um dentifrício dessensibilizante contendo biovidro (Sensodyne®Repair&Protect, GlaxoSmithKline Brasil Ltd., Rio de Janeiro, Brasil), quanto ao potencial de obliteração dos túbulos dentinários e compará-lo com os dentifrícios convencionais (Colgate® Sensitive Pro-Alívio™, Colgate-Palmolive, São Paulo, SP, Brasil eSensodyne® Rápido Alívio, GlaxoSmithKline Brasil Ltd., Rio de Janeiro, Brasil). Foram utilizados 12 pré-molares humanos divididos em: G1 (n=4) - escovação com Colgate®Sensitive Pró-Alívio; G2 (n=4) - escovação com Sensodyne® Rápido Alívio; e G3 (n=4) - escovação com Sensodyne®Repair&Protect. As amostras foram submetidas à simulação de escovação de um período de oito semanas, com duas escovações diárias e analisadas em microscopia eletrônica de varredura (MEV), quanto à presença e características dos túbulos dentinários; a espectroscopia de raios-X por dispersão em energia (EDS), a fim de avaliar os elementos químicos presentes nos túbulos dentinários. A análise qualitativa da obliteração dos túbulos dentinários foi avaliada por meio das fotomicrografias. Para verificar a distribuição normal dos dados da EDS, utilizou-se o teste de Shapiro-Wilk (p<0,05). De acordo com a normalidade apresentada, foram executados teste t-Studentde amostras pareadas e teste de Wilcoxon. No grupo G1 foi verificada diminuição na luz dos túbulos dentinários, enquanto no G2, além da diminuição dos túbulos, nítida deposição de partículas obliteradoras foi observada. No G3, foi detectada não só a obliteração dos túbulos, mas também a diminuição na quantidade dos mesmos; além da formação de uma camada de hidroxidocarbonato de apatita (HCA)sobre a dentina. A análise conjunta dos dados permitiu concluir que os dentifrícios testados foram capazes de ocluir os túbulos dentinários e que o dentifrício Sensodyne®Repair&Protect apresentou melhor eficácia na obliteração dos túbulos dentinários, seguido respectivamente dos dentifrícios Sensodyne® Rápido Alívioe Colgate®Sensitive Pró-Alívio.

Nano/micro fluorhydroxyapatite crystal pastes in the treatment of dentin hypersensitivity: an in vitro study

OBJECTIVES

Dentin hypersensitivity (DH) is a prevalent problem. This study aimed to formulate a paste using fluorhydroxyapatite (FA) crystals dispersed in different carriers to treat DH. The ability to occlude patent dentinal tubules and to release ions was investigated.

MATERIALS AND METHODS

Twenty percent FA/sodium alginate, 40% FA/poly(hydroxyethyl methacylate(HEMA)), and 40% FA/poly(DMA-co-MEA) were applied to etched dentin samples and examined with scanning electron microscopy (SEM) to determine the degree of tubule occlusion. Fluoride electrode was used to measure F release and spectroscopy to evaluate Ca and PO4 release. The cytotoxicity of the synthesized poly(DMA-co-MEA) gel was tested. Kruskall-Wallis test was used to test the differences in ion release between the groups.

RESULTS

FA/poly(DMA-co-MEA) paste obstructed up to 80% of the dentinal tubules, while the coverage was up to 70% for FA/poly(HEMA) and less than 50% for FA/sodium alginate. Fluoride and Ca release was the highest for FA/P(HEMA), 7.2 ± 0.7 and 139.8 ± 32.5 ppm, respectively. The highest concentration of PO4 was 46.2 ± 16.4 ppm for FA/Sodium alginate. No statistical significance was found.

CONCLUSIONS

FA/Poly(DMA-co-MEA) and FA/poly(HEMA) pastes may offer immediate short-term relief of DH because of their ability to occlude the tubules and adhere to wet dentin surfaces. The release of the F, Ca, and PO4 ions may offer long-term relief by forming a mineral barrier both within the dentinal tubules and on the dentin surface.

CLINICAL SIGNIFICANCE

The tested materials may offer a long-term treatment for DH.

Bioactivity of toothpaste containing bioactive glass in remineralizing media: effect of fluoride release from the enzymatic cleavage of monofluorophosphate

Objectives. The aim was to introduce a new methodology to characterize toothpaste containing bioactive glass and to evaluate the effect of release of fluoride ions, by cleaving monofluorophosphate (MFP), on the mineral forming ability of Sensodyne Repair & Protect (SRP). which contains NovaMinTM (bioactive glass, 45S5 composition).

Methods. SRP, NovaMin particles, and placebo paste (PLA) which did not contain NovaMin, were immersed into a remineralization media (RS), which mimics the ionic strength of human saliva, for 3 days with different concentrations of alkaline phosphatase (ALP): 0, 25 and 75 U.L

Results. Hydroxyapatite (HA) formed on the surface of BG alone (after 1 h) and in toothpaste (after 2 h), whereas PLA did not induce any precipitation. ALP cleaved MFP at different rates depending on the enzyme concentration. Increasing the concentration of ALP from 0 and 75 U.L