Nano-hydroxyapatite Paste Research Articles

Comparative evaluation of surface changes and bond strength of microabrasion bleached enamel before and after remineralization with nano-hydroxyapatite paste: In vitro study

Objectives: Comparative evaluation of surface changes and bond strength of Microabrasion Bleached enamel before and after Remineralization with Nano-hydroxyapatite paste, an In vitro study. Methods: Enamel samples were divided into - Group I - Conventional bleaching (HB), Group II - Conventional bleaching with remineralization (HB+N-Hp), Group III - Microabrasion-assisted bleaching (M+HB), and Group IV - Microabrasion-assisted bleaching with remineralization (M+HB+N Hp). Surface roughness was measured using a profilometer. Samples were stored in artificial saliva for two weeks, then bonded with nanofilled composite resin and subjected to shear bond strength (SBS) analysis. Results: Group IV (M+HB+N-Hp) showed higher surface roughness than Groups I (HB) and II (HB+N-Hp), while Group II had significantly lower surface roughness compared to Groups III (M+HB) and IV. In terms of shear bond strength (SBS), Group III exhibited significantly higher SBS than Group I, whereas Group II showed significantly reduced SBS compared to Group I. All values were statistically significant. Conclusions: Remineralization with N-Hp reduces the surface roughness caused by bleaching and microabrasion, potentially decreasing bacterial biofilm adherence. Despite increased surface roughness correlating with better bond strength, microabrasion-assisted bleaching followed by remineralization and direct composite veneering after two weeks is a promising minimally invasive treatment for severe tooth discolorations. Further studies should explore varying frequencies and concentrations of N-Hp application.

Remineralization Potential of Nanostrontium/Fluoride Hydroxyapatite on Artificial Enamel Caries

Objectives: This study aimed to evaluate the remineralization efficacy of nano-strontium/ fluoride hydroxyapatite paste on initial enamel caries in comparison with other remineralization products under a simulated pH-cycling model. Methods: Following the artificial caries induction, forty enamel specimens with noncavitated lesion in the same range of lesion depth were selected by mean of micro-CT evaluation. The specimens were block-randomized into four experimental groups regarding remineralizing pastes: 1500 ppm sodium fluoride paste, 10%wt nano-hydroxyapatite paste, 10%wt nano-strontium/fluoride hydroxyapatite paste and 5%wt nano-strontium/ fluoride hydroxyapatite paste. Remineralizing effect was evaluated using micro-CT, while SEM/EDS line scan mode facilitated the investigation of remineralization patterns. Changes in lesion depth (ΔLD) and changes in mineral loss (ΔΔZ) were evaluated at 7 and 14 days of treatment under the pH-cycling model. Statistical analyses were performed using 2-way ANOVA and post hoc Tukey’s test (p<0.05). Results: The use of 5%wt nano-strontium/fluoride hydroxyapatite paste significantly reduced lesion depth in initial caries under experimental conditions. Meanwhile, the 10%wt nano-strontium/fluoride hydroxyapatite paste yielded the highest mineral gain, though statistically insignificant. EDS graphs indicated an increasing calcium and phosphorus deposition trend over time with nano-strontium/fluoride hydroxyapatite paste, revealing a more uniform mineral distribution compared to both sodium fluoride and nano-hydroxyapatite pastes. Nevertheless, neither fluorine nor strontium was detectable in these graphs. Conclusions: The study revealed comparable remineralization efficacy with 5%wt and 10%wt nano-strontium/fluoride hydroxyapatite pastes. The treatment durations of 7 and 14 days showed no significant difference in outcomes.

Correction: An assessment of microstructure, dentinal tubule occlusion and X-ray attenuation properties of Nd: YAG laser-enhanced titanium-doped phosphate glass and nano-hydroxyapatite pastes

Correction: An assessment of microstructure, dentinal tubule occlusion and X-ray attenuation properties of Nd: YAG laser-enhanced titanium-doped phosphate glass and nano-hydroxyapatite pastes

An assessment of microstructure, dentinal tubule occlusion and X-ray attenuation properties of Nd:YAG laser-enhanced titanium-doped phosphate glass and nano-hydroxyapatite pastes

An assessment of microstructure, dentinal tubule occlusion and X-ray attenuation properties of Nd:YAG laser-enhanced titanium-doped phosphate glass and nano-hydroxyapatite pastes

Antibacterial activity of nano-hydroxyapatite paste of snakehead fish bone against S. mutans: an in vitro study

ABSTRACTIntroduction: Caries is the most common oral disease found in society. The prevalence of caries in South Kalimantan is as high as 46.9% in 2018. S.mutans is the causative microorganism in the initial occurrence of caries. Strategy that can be used to prevent caries is by adding nano-hydroxyapatite to the tooth paste. Nano-hydroxyapatite can be obtained from Snakehead (Channa striata) fish bone. Snakehead is a kind of fish that is abundant in Banjarmasin. This study aimed to analyze antibacterial activity of the nano-hydroxyapatite paste from snakehead (Channa striata) fish bone against S.mutans bacteria. Methods: The study consisted of 5 treatment groups: negative control (basic formula), positive control (casein phosphopeptide-amorphous calcium phosphate or CPP-ACP) and three treatment groups (nano-hydroxyapatite paste concentration of 10, 20 and 30%. The paste was made in the formulation of F1, F2, and F3. The antibacterial activity test by measuring MIC and MBC were performed using dilution method. Results: MIC of nano-hydroxyapatite paste was at a concentration of 10% with an average value of the difference absorbance of -0.468. MIC values in the concentration of 10%, 15%, 20% positive and negative control groups had a significant difference. MBC of nano-hydroxyapatite paste was at concentration of 15%. Concentration of 10% and the negative control group showed a significant difference, while concentration of 15% and 20% groups did not show a significant difference. Conclusion: Nano-hydroxyapatite paste from Snakehead fish bone has antibacterial activity in inhibiting and eliminating mutated S.mutans bacteria. The most effective concentration of antibacterial nano-hydroxyapatite paste to prevent caries was 10%. At this concentration, nano-hydroxyapatite can inhibit the growth of S.mutans without killing the bacteria.KEYWORDS fish bone, nano-hydroxyapatite, snakehead, S.mutans

Remineralization potential of strontium-doped nano-hydroxyapatite dentifrice and casein phosphopeptide-amorphous calcium phosphate cream on white spot lesions in enamel following orthodontic debonding - a randomized controlled trial.

This study was intended to compare and determine the potency of strontium-doped nano-hydroxyapatite paste against a topical cream containing casein phosphopeptide-amorphous calcium phosphate and a regular dentifrice for remineralization of white spot lesions of enamel following orthodontic debonding. Ninety individuals with white spot lesions on their enamel who visited the orthodontic department for de-bonding were selected for the research. Patients were randomly assigned to three distinct groups with each group consisting of 30 patients. Group 1 served as the control and received regular dentifrice, Group 2 received strontium-doped nano-hydroxyapatite paste, and Group 3 received casein phosphopeptide-amorphous calcium phosphate topical cream. Patients were instructed to locally apply a specified amount of the prescribed preparation twice daily for six weeks. The data were analysed using the statistical programme SPSS 22.0 (SPSS Inc., Chicago, IL, USA), and the level of significance had been set at p < 0.05. Group 1 did not show any change in the enamel following the application of toothpaste. Both Group 2 and 3 demonstrated higher post-treatment scores, indicating effective remineralization potential (p < 0.001). However, Group 2 (strontium-doped nano-hydroxyapatite paste) displayed significantly greater remineralization capacity when compared to group 3 (casein phosphopeptide-amorphous calcium phosphate topical cream). Compared to conventional dentifrice and casein phosphopeptide-amorphous calcium phosphate paste, strontium-doped nano-hydroxyapatite preparation demonstrated greater enamel remineralization of the white spot lesions and favourable surface alterations in the enamel surface. strontium-doped nano-hydroxyapatite can be utilised safely and efficiently to treat early caries and remineralise white spot lesions on the enamel.

Development and Elemental Analysis of a Novel Strontium-Doped Nano-Hydroxyapatite Paste and Evaluation of Its Remineralization Potential: An In Vitro Study

Development and Elemental Analysis of a Novel Strontium-Doped Nano-Hydroxyapatite Paste and Evaluation of Its Remineralization Potential: An In Vitro Study

Clinical and Radiographic evaluation of Nanohydroxyapatite paste on pulpotomized primary molars

Clinical and Radiographic evaluation of Nanohydroxyapatite paste on pulpotomized primary molars

Radiological Comparative Study Between Conventional and Nano Hydroxyapatite With Platelet-Rich Fibrin (PRF) Membranes for Their Effects on Alveolar Bone Density.

The entry of the concept of nanotechnologies into the field of biomaterials has improved the results of their use in regenerative therapies based on the principles of tissue engineering, due to its improvement of the physical properties of materials manufactured in this way, so it has become possible to produce particles of hydroxyapatite in nano sizes. This study will evaluate the efficacy of applying nanohydroxyapatite paste and platelet-rich fibrin (PRF) as a barrier membrane in comparison with traditionalhydroxyapatite (a powder consisting of macro-sized particles) and PRF as a barrier membrane in symmetrically extracted alveoli of the mandible. The research sample consisted of 40 lower alveoli (symmetrical) of the extracted teeth. The study samples were divided randomly into two groups. Group 1: A paste of nanohydroxyapatite with PRF as a barrier membrane was applied to one side of the extraction. Group 2: Hydroxyapatite powder with PRF as a barrier membrane was applied to the alveolus from the opposite side of Group 1 (the opposite side of the extraction). Three radiographs were performed by cone beam conventional tomography (CBCT) in three consecutive periods to conduct the radiological study (T0: immediately after extraction and grafting, T1: after three months, T2: after six months). The mean of the radiographic bone density of the hydroxyapatite powder group at time T0 is 824.36 HU with a standard deviation of ±277.29 HU, and at time T1 is 1119.93 HU with a standard deviation of ±306.93 HU, and at time T2 is 1074.14 HUwith a standard deviation of ±223.62 HU, with statistically significant differences when comparing the amount of change in radiographic bone density at time T0 and T1 withP < 0.05, and at time T0 and T2 with P < 0.05, but there were no significant differences when comparing the amount of change in radiographic bone density in T1 and T2 times with P > 0.05. The mean radiographic bone density of the nanohydroxyapatite paste group at time T0 is 629.88 HU with a standard deviation of ±193.64 HU, and at time T1 is 960.67 HU with a standard deviation of ±256.88 HU, and at time T2 is 743.87 HU with a standard deviation of ±180.96 HU, and in the time T0 and T1 with P < 0.05, and in the time T0 and T2 with P < 0.05, and in the time T1 and T2 with P < 0.05. Statistically, significant differences have been found between bone density change T1, T2in the nanohydroxyapatite paste group and bone density change T1, T2in the hydroxyapatite powder group P<0.05, which expresses a greater loss of density in the nanohydroxyapatite group, and thus the resorption of the bone graft and the placement of new bone tissue. Within the limits of our study, the results demonstrated that the use of traditional hydroxyapatite powder and nanohydroxyapatite paste increases the radiographic bone density, nanohydroxyapatite paste has a greater absorbency after 3 months compared with traditional hydroxyapatite powder which helps replace it by natural bone tissue.

Effect of Diode Laser and Remineralizing Agents on Microstructure and Surface Microhardness of Therapeutic Gamma-Irradiated Primary Teeth Enamel

BACKGROUND: Radiation caries is a serious complication to head and neck cancer (HNC) radiotherapy, for which the primary teeth are more susceptible to be affected. Preventive protocols are recommended to enhance dental structure resistance against the direct effects of radiotherapy. AIM: The aim of the study is to evaluate the effect of diode laser and two types of remineralizing agents on the microhardness of the primary teeth enamel and examine microstructural alterations. METHODS: Twenty primary molars were sectioned into two halves in a mesiodistal direction, to obtain 40 specimens, which were then randomly allocated into five groups. Group 1 (Control Negative) n = 5 was not subjected to any treatment or radiation. Group 2 (Control positive) n = 5 was gamma irradiated with a dose of 60 Gray. For Groups 3, 4, and 5, specimens were divided into two subgroups: A and B (n = 5/subgroup). Subgroups A were gamma irradiated, then exposed to different surface treatments: 3A:10% nano-hydroxyapatite (nHA) paste, 4A: 5% sodium fluoride varnish (FV), and 5A: diode laser 980 nm. Subgroups B were exposed to surface treatments (3B: 10% nHA, 4 B: 5% FV, and 5B: diode laser 980 nm), then gamma irradiated. Surface micromorphology and microhardness were examined using environmental scanning electron microscope (ESEM), and Vickers microhardness tester, respectively. RESULTS: Group 2 (G) specimens possessed the lowest mean microhardness, while nHA-G (3B), G-Fl (4A), and L-G (5B) had significantly higher values. ESEM analysis showed an alteration in Group G and the obliteration of enamel micropores with remineralizing agents. The melting and fusion of enamel in laser subgroups were also observed. CONCLUSIONS: The findings indicated that using FV, nHA, or diode laser increased microhardness and maintained the integrity of the enamel microstructure. Therefore, applying preventive strategies should be considered in HNC radiotherapy.

Stimulation of Metabolic Activity and Cell Differentiation in Osteoblastic and Human Mesenchymal Stem Cells by a Nanohydroxyapatite Paste Bone Graft Substitute.

Advances in nanotechnology have been exploited to develop new biomaterials including nanocrystalline hydroxyapatite (nHA) with physical properties close to those of natural bone mineral. While clinical data are encouraging, relatively little is understood regarding bone cells’ interactions with synthetic graft substitutes based on this technology. The aim of this research was therefore to investigate the in vitro response of both osteoblast cell lines and primary osteoblasts to an nHA paste. Cellular metabolic activity was assessed using the cell viability reagent PrestoBlue and quantitative, real-time PCR was used to determine gene expression related to osteogenic differentiation. A potential role of calcium-sensing receptor (CaSR) in the response of osteoblastic cells to nHA was also investigated. Indirect contact of the nHA paste with human osteoblastic cells (Saos-2, MG63, primary osteoblasts) and human bone marrow-derived mesenchymal stem cells enhanced the cell metabolic activity. The nHA paste also stimulated gene expression of runt-related transcription factor 2, collagen 1, alkaline phosphatase, and osteocalcin, thereby indicating an osteogenic response. CaSR was not involved in nHA paste-induced increases in cellular metabolic activity. This investigation demonstrated that the nHA paste has osteogenic properties that contribute to clinical efficacy when employed as an injectable bone graft substitute.

A Comparative Evaluation of Remineralization Potential of Nano-Seashell, Nano-Pearl, and Nano-Hydroxyapatite Pastes Versus Fluoride-Based Toothpaste on Non-Cavitated Initial Enamel Lesion: An In Vitro Study.

A Comparative Evaluation of Remineralization Potential of Nano-Seashell, Nano-Pearl, and Nano-Hydroxyapatite Pastes Versus Fluoride-Based Toothpaste on Non-Cavitated Initial Enamel Lesion: An In Vitro Study.

Comparative evaluation of remineralisation potential of bioactive glass, casein phosphopeptide-amorphous calcium phosphate and novel strontium-doped nanohydroxyapatite paste: An In-Vitro study.

Many studies explained the importance of remineralisation of early carious lesions with various remineralising agents. In the present study, we incorporated the remineralising agents in a dentifrice, applied that in artificial enamel caries and evaluated their remineralising potential and compared the efficacy among the three. To evaluate and compare the remineralisation potential of a dentifrice containing bioactive glass, casein phosphopeptide-amorphous calcium phosphate and novel laboratory synthesised strontiumdoped nanohydroxyapatite paste in artificial enamel caries. 120 enamel specimens were divided into 4 groups of 30 specimens each, based on the type of dentifrice applied: GI - conventional toothpaste (control group), GII - calcium sodium phosphosilicate (Novamin), GIII - casein phosphopeptide-amorphous calcium phosphate (GC tooth mousse) and GIV- Novel strontiumdoped nanohydroxyapatite paste (SrnHAp paste). Specimens in all the groups were subjected to demineralisation, and calcium/phosphorous ratio was analysed followed by remineralisation and the mean calcium-phosphorus ratio was assessed using a scanning electron microscope and energy dispersing X-ray analysis. Data were analysed using IBM SPSS Statistics for Windows Software, version 22 (IBM Corp., Armonk, NY, USA). Descriptive statistics were used to calculate the mean and standard deviation. Kruskal-Wallis, ANOVA and Mann-Whitney tests were used. The level of significance was set at 5%. All except the control group showed a net increase in calcium and phosphorous values after application of the respective remineralising agents in respective groups. Inter-group comparison revealed that Group IV - SrnHAp paste yields higher net calcium and phosphorous values than other groups. Hence, novel SrnHAp can be considered as the material of choice in remineralising early enamel carious lesions.

Rehardening and the Protective Effect of Gamma-Polyglutamic Acid/Nano-Hydroxyapatite Paste on Surface-Etched Enamel.

Many revolutionary approaches are on the way pertaining to the high occurrence of tooth decay, which is an enduring challenge in the field of preventive dentistry. However, an ideal dental care material has yet to be fully developed. With this aim, this research reports a dramatic enhancement in the rehardening potential of surface-etched enamels through a plausible synergistic effect of the novel combination of γ-polyglutamic acid (γ-PGA) and nano-hydroxyapatite (nano-HAp) paste, within the limitations of the study. The percentage of recovery of the surface microhardness (SMHR%) and the surface parameters for 9 wt% γ-PGA/nano-HAp paste on acid-etched enamel were investigated with a Vickers microhardness tester and an atomic force microscope, respectively. This in vitro study demonstrates that γ-PGA/nano-HAp treatment could increase the SMHR% of etched enamel to 39.59 ± 6.69% in 30 min. To test the hypothesis of the rehardening mechanism and the preventive effect of the γ-PGA/nano-HAp paste, the surface parameters of mean peak spacing (Rsm) and mean arithmetic surface roughness (Ra) were both measured and compared to the specimens subjected to demineralization and/or remineralization. After the treatment of γ-PGA/nano-HAp on the etched surface, the reduction in Rsm from 999 ± 120 nm to 700 ± 80 nm suggests the possible mechanism of void-filling within a short treatment time of 10 min. Furthermore, ΔRa-I, the roughness change due to etching before remineralization, was 23.15 ± 3.23 nm, while ΔRa-II, the roughness change after remineralization, was 11.99 ± 3.90 nm. This statistically significant reduction in roughness change (p < 0.05) implies a protective effect against the demineralization process. The as-developed novel γ-PGA/nano-HAp paste possesses a high efficacy towards tooth microhardness rehardening, and a protective effect against acid etching.

Comparative Assessment of remineralizing potential of recent biomimetic remineralizing agents on sub-surface carious lesions: An in vitro study

Introduction: Enamel demineralization and remineralization are considered dynamic and continuous process that occurs throughout the life. Subsurface caries is distinct when the amount of subsurface minerals missed go above the amount of minerals secured. The biomimetic remineralizing protocol is planned to encourage maximum maintenance of healthy dental hard tissues in subsurface stage. Aim: Directed to assess the remineralizing potential of self-assembling peptide P11-4, phosphorylated chitosan and nano hydroxyapatite paste on subsurface carious lesions. Materials and methods: Forty sound non-carious human anterior teeth were used. The teeth were divided into four groups (10 teeth each). Group A1: control; Group A2: using Curodont repair; Group A3 using phosphorylated chitosan and; Group A4: using nanohydroxyapatite paste. All products were applied according to the manufacturer's instructions and each group was subdivided into two groups according to the storage time group B1: 3 months and group B2: 6 months. Calcium and phosphorous weight and ratio were assessed using dispersive X-ray energy and Diagnodent pen at base line then after 3and 6months. The mean and standard deviation values were calculated for each group in each test. Results: Specimens treated with Curodont repair after six months record the highest mean value while the lowest mean value was found in artificial saliva, also for all remineralizing agents (Curodont repair, phosphorylated chitosan, and Nanohydroxyapatite paste) and control group the remineralization potential was increased by increasing the storage time (three month and six months). Conclusion: Curodont repair is considered a valuable biomimetic remineralizing agent. Keywords: Remineralization, Chitosan, self-assemblingpeptideP11-4, Nanohydroxyapatite paste.

Impact of using nano-hydroxyapatite on postoperative hypersensitivity of two bleaching techniques – randomized controlled clinical trial

To evaluate the impact of using Nano-hydroxyapatite on post-bleaching hypersensitivity after using two different bleaching techniques. Twenty-eight patients were enrolled in this study according to inclusion and exclusion criteria. The patients were randomly assigned into four groups (n=7). G1; bleaching was performed using photo-catalyzed bleaching technique (Philips, zoom), followed by application of Amorphous Calcium phosphate based desensitizing agent (ACP, Relief ACP). G2; bleaching was performed using chemo-catalyzed bleaching technique (Philips, Dash), followed by application of ACP. G3: bleaching was performed using zoom, followed by application of nano-hydroxyapatite based desensitizing agent (Nano p), G4: bleaching was performed using Dash, followed by application of Nano-hydroxyapatite. Post bleaching hypersensitivity was assessed using “Visual analogue scale”. Hypersensitivity was evaluated after: bleaching immediately, application of the desensitizing agent immediately, 24 hours, 48 hours and after one week. Cases with severe hypersensitivity were relieved immediately after Nano p application, meanwhile in case of ACP, cases with severe pain were relieved after 24 hours after its application. Statistically significant difference was evident with the photo catalyzed group immediately after Nano p application than before its application. Reduction in hypersensitivity by time was evident in both the chemo and photo catalyzed groups. In addition, it was found that after one week, all pain scores disappeared with all tested groups. Nano hydroxyapatite particles have an immediate (just post application) relief effect of severe pain with both used bleaching systems. However, the post bleaching hypersensitivity diminished completely after 1 week, irrespective of the desensitizing agent used. The application of Nano hydroxyapatite paste after bleaching is a valid method for diminishing severe post bleaching hypersensitivity when applied with either a photo or chemo catalyzed bleaching agents.

Clinical efficacy of single application of plain nano-hydroxyapatite paste in reducing dentine hypersensitivity - A randomized clinical trial

Introduction: The study aimed to compare the efficacy of a single application of plain nano-hydroxyapatite (n-HA) paste in reducing dentine hypersensitivity. Materials and Methods: Sixty-three patients were recruited to participate in the study and randomized to be allocated into three groups (n-21): (1) Group 1 – n-HA paste, (2) Group 2 – fluoride paste, and (3) Group 3 – placebo. The patient's response to dentin hypersensitivity (DH) was evaluated at baseline (T0), immediately after application (T1), and after 1 week (T2). Tactile and cold air sensitivity (CAS) stimulus tests and visual analog scale subjective tests were used to measure the patient's response to DH. The data analysis was performed using the Statistical Package for the Social Sciences statistical software. Results: All three groups showed a statistically significant reduction in tactile sensitivity (TS), cold air sensitivity, and visual analog scale scores from T0–T1 and T0–T2 (P 0.005) except for Group 1, which showed a significant reduction (P = 0.033) in visual analog scale scores from T1–T2. However, the intergroup comparison at T2 demonstrated a significant difference in tactile scores (P = 0.005), CAS (P Conclusion: n-HA paste was the most effective desensitizing paste compared to fluoride and placebo pastes. The single application of the n-HA paste demonstrated a significant reduction in visual analog scale scores after 1-week.

Development of strontium-doped nano hydroxyapatite dentifrice and compare its remineralising potential with a topical cream containing casein phosphopeptide- amorphous calcium phosphate - An In Vitro study.

To develop and evaluate the efficacy of synthesised strontium-doped nano hydroxyapatite dentifrice and compare its remineralizing potential with a topical cream containing Casein Phospho Peptide - Amorphous Calcium Phosphate, in remineralizing artificial carious lesion on enamel. Enamel specimens of 4 x 4 x 1 mm were prepared from 90 freshly extracted teeth. Specimens were divided into 3 groups of 30 samples each, based on the type of dentifrice applied that is a control group (Group I) and two experimental groups (Groups II, III). Surface topography and the calcium/phosphorous ratio of all sound specimen were evaluated using Scanning electron microscope and Energy Dispersive X-ray Analysis (SEM-EDAX). The samples in group I and each of the experimental groups were subjected to demineralisation and the calcium/phosphorous ratio of the demineralized specimen were analysed. The samples were then subjected to remineralisation using different agents in each group. Samples in the control group (Group I) were brushed with a conventional dentifrice. In the experimental groups, Group II topical cream with Casein Phosphopeptide and Amorphous Calcium phosphate (CPP-ACP) was used and in Group III laboratory synthesized Strontium-doped nanohydroxyapatite paste (Sr-nHAP), respectively for 28 consecutive days. The samples in the both the control and the two experimental groups were again subjected to SEM-EDAX analysis to analyse the calcium phosphorus ratio following remineralisation cycle. Groupwise comparison of the data was done with one way ANOVA followed by Tukeys Post hoc Test. Both experimental groups (II, III) showed statistically significant remineralisation potential after demineralisation, compared to the control group I. Intergroup comparison showed that the samples in Group III showed the higher remineralisation potential than Group II and was statistically significant. Both CPP- ACP containing tooth cream as well as Sr doped nHAp showed remineralisation potential. Sr doped nanohydroxyapatite showed better remineralisation than CPP ACP and can be considered for enamel repair in incipient carious lesions.

Photo-crosslinked alginate nano-hydroxyapatite paste for bone tissue engineering

In this study, methacrylation of alginate was carried out by reacting sodium alginate with methacrylic anhydride in the presence of sodium hydroxide. Separately synthesized nano-hydroxyapatite (nano-HAp) powder was surface functionalized using mercaptopropionic acid and ethylene glycol methacrylate phosphate (EGMP) in the presence of azobisisobutyronitrile benzene as a free radical initiator in a nitrogen atmosphere. Methacrylated alginate solution was mixed with the required amount of surface-functionalized HAp nanoparticles in the presence of 0.05% Irgacure 2959 as a photoinitiator and was placed at the centre of a 8 kW UV light source (265 nm) to prepare photo-crosslinked bone paste. X-ray diffraction analysis indicated that surface functionalization did not alter phase purity of HAp nanopowder in the prepared paste. The graft polymerization of EGMP on the surface of HAp was confirmed by the presence of the 1732 cm−1 band, which belongs to C=-O stretching of EGMP, in addition to the characteristic peaks of nano-HAp and alginate in the composite paste. The storage and loss moduli of all the prepared pastes increased non-linearly with time up to 100 s, demonstrating their pseudo plastic behaviour. The rate of release of bone morphogenetic protein 2 (BMP-2) was significantly faster in the first few days, and the release curve gradually levelled off prior to slowing down up to 22 d. Mesenchymal stem cell adhesion studies revealed that cells could attach to the paste material and stretch over the surface of the material after 14 d of incubation. MTT assay showed that prepared paste materials were conducive to attachment and proliferation of mesenchymal stem cells. Immunocytochemical analysis revealed that the addition of surface-functionalized nano-HAp and BMP-2 to alginate hydrogel enhanced the osteogenic potential of the prepared paste. The results indicate that the newly developed photo-crosslinked paste may be physically and biologically suitable for application as a bone filler.

In situ Effects of Nanohydroxyapatite Paste Derived from Chicken Eggshell on Tooth Enamel During Two Bleaching Regimens

In situ Effects of Nanohydroxyapatite Paste Derived from Chicken Eggshell on Tooth Enamel During Two Bleaching Regimens