Table 1.

Recent Evidences on the Nanohydroxyapatite Application in the Field of Dental Implantology, Dentin Hypersensitivity Management, Bleaching, and Dental Caries Prevention and Restoration of Teeth.

Authors, Year of Publication	Type of Study	Aim of the study	Conclusion
Yadav and Meena, 2022 [70]	In -vitro	Formed a resin-based micro-nano particulate-filled restorative composite and analyzed the consequence of variable nHA filler concentration on their thermomechanical and thermogravimetric properties.	Thermal stability was better with Aluminium oxide-nHA filled dental composite t than Titanium dioxide–nHA filled dental composite
Soares et al., 2022 [78]	In -vitro	Studied the activity of human dental pulp cells on polycaprolactone/nHA nanofibrous scaffolds, for dentin regeneration in vital pulp therapy	Mineralized matrix formed after 21 days was 9 times higher for PCL + 2%nHA formulation as compared with the control
Baskar et al., 2022 [79]	In -vitro	Assessed odontogenic differentiation capabilities of porous bio-mineralizable composite scaffolds with eggshell derived nHA and Carboxymethyl Chitosan (CMC) on dental pulp stem cells.	DPSCs on 1:5 nHA-CMC scaffolds showed enhanced cell viability nd proliferation along with increased expression of DSPP as well as VEGF
Ardani et al., 2022[80]	In -silico	Evaluated the binding molecular docking of Polyether Ether Ketone (PEEK) incorporated with nHA as a biomaterial for orthodontic mini-implant fabrication	PEEK with nHA displayed a striking binding affinity with ALP and IGF-1 osteogenic markers and hence has increased potential for osseointegration.
Netalkar et al., 2022[81]	In -vitro	Evaluated the effect of nHA incorporation on fluoride releasing ability, penetration, and adaptation of pit and fissure sealant.	The nHA incorporated sealant showed more samples with no bubbles or debris. The fluoride releasing ability was higher in nHA incorporated sealant group.
Tamburaci and Tihminlioglu 2021[82]	In -vitro	Fabricated a bilayer nanocomposite membrane with microporous sublayer composed of chitosan and silicon doped nanohydroxyapatite particles (Si-nHap) and chitosan/polyethylene oxidenanofiber upper layer.	Novel bilayer nanocomposite membranes can be utilised as a material for guided bone regeneration in dentistry especially in periodontal applications.
Niu et al., 2021[83]	In- vitro	A novel polyamide-6/chitosan@nano-hydroxyapatite/polyamide-6 (PA6/CS@n-HA/PA6) bilayered tissue guided membranes was formed.	PA6/CS@n-HA/PA6 bilayered scaffolds exhibited safety, good bioactivity, biocompatibility and osteo-conductivity for bone regeneration
Fang et al., 2022 [84]	In -vitro	A scaffold using gelatin, nano-hydroxyapatite, metformin(GHMS) was made and its effectiveness in bone regeneration was studied in a rat alveolar bone defect model.	GHMS showed superior bone regeneration compared to extraction-only, Sinbone and Bio-Oss Collagen groups.
Amaechi et al., 2022 [85]	RCT	Investigated whether combined usage of nHA dental lotion (Apagard Deep Care) after tooth-brushing with nanoHAP toothpaste (Apagard M−plus) enhanced the remineralization process.	The application of a dental lotion containing 5% nHA after brushing resulted in superior remineralization compared to a placebo lotion.
Yoshida et al., 2021 [86]	In -vitro	Studied the effectiveness of dental adhesive material Super-bond (SB), which included 10%, 30%, and 50% nHA (naHAp/SB) on odontoblastic differentiation of dental pulp stem cells) and the formation of reparative dentin was also investigated.	30% nHA/SB promoted maximum reparative dentin formation and hence can be used as an apt direct pulp capping agent.
Gamal et al., 2022 [87]	Animal Study	Compared histologically the bone regenerative ability of combination of hyaluronic acid (HLA) with nanohydroxyapatite (HANP)and using HANP alone in treating bony defects in rabbit calveria.	Both the groups showed bone formation but with the HLA + HANP group the bone formation was better as HLA accelerated the initiation of new bone production when coupled with HANP.
Sharifi et al., 2022 [88]	In-vitro study	Formed and analyzed the properties of a novel root repair material with nHA, Portland cement, and bismuth oxide.	There was a significant increase in cell viability in the novel root repair material containing hydroxyapatite nanoparticles after 3 and 7 days
Bozoglu et al., 2022 [89]	In-vitro	Osteogenic potential of PEEK implants coated with boron doped nHA on periodontal ligament cells	Enhanced periodontal ligament cells adhesion and proliferation on the surface of PEEK implants coated with boron doped nHA compared with untreated PEEK implants
Ji, D. and Lu, D 2022 [90]	In-vitro and Animal study	Effect of nHA composite polyamide 66 at the interface between bone tissue and titanium implants on repairing type II diabetics bone defects	Enhanced bone repair nHA composite polyamide 66 material showed enhance bone repair between bone and implant. The material had good biocompatibility and less cytotoxicity
Karthika, 2022 [91]	In vitro	Fe (III) and Cu (II) incorporated hydroxyapatite coatings (Fe/Cu-HAP) on titanium implant was developed and assessed for biocompatibility and antibacterial activity	Fe/Cu-HAP coating on titanium implant showed uniform deposition with improved biocompatibility and bioactivity. The coating had improved antibacterial activity against Staphylococcus aureus and Escherichia coli
Hajinaebi et al., 2022 [92]	In-vitro	Ciprofloxacin (CIP) was loaded onto a nHA-coated Ti-6Al-4 V implant.	Implant coated with CIP-nHA showed crack-free homogenous coating on the surface with sustained release of CIP. The antibacterial activity of S. aureus and E. coli was higher on the implants coated with CIP-nHA
Moharam et al., 2022 [30]	Clinical study	Effect of 2.5% Arginine and nHA application on the post-bleaching hypersensitivity and color change.	The use of desensitising agents had no effect on the bleaching outcome, but there was a statistically significant colour change.
Alsen et al., 2022 [93]	Clinical study	Comparison of nHA with fluoride for the treatment of dentin hypersensitivity following ultrasonic scaling:	Both fluoride and nHA had similar effect
Vitiello et al., 2022 [94]	In-vitro	Remineralization potential of CPP-ACP mousse nHA gel, 5% SF varnish, ACP functionalized with fluoride and carbonate-coated with citrate toothpaste and	CPP-ACP mousse nHA gel showed better surface remineralization compared other remineralizing agents
Elembaby et al., 2022 [95]	In-vitro	Effect of nHA incorporation into resin infiltrant on the mineral content, surface tomography, and resin tag penetration of demineralized enamel.	High-quality resin tags in demineralized enamel with enhanced mineral density, resin penetration and smooth surfaces
Wahba et al., 2022 [96]	In-vitro	Comparison of fluoride varnish, fluoride mouthwash, Self- Assembling Peptide (P11-4), CPP-ACP, and nHA in prevention and arrest of Primary Tooth Enamel Lesions	Fluoride varnish, fluoride mouthwash showed caries-preventive effects whereas other agents did not show any effect
Sebastian et al., 2022 [97]	In-vitro	Comparison of CPP-ACP, nHA and Calcium Sucrose Phosphate (CSP) on artificial enamel lesion	CSP showed highest surface microhardness followed by nHA and CPP-ACP
Erdilek et al., 2022 [98]	In-vitro	Comparison of remineralization potential of fluoride gel, sodium fluoride toothpaste, and homemade nHA paste on artificial early enamel caries.	Homemade nHA paste had a enhanced remineralization potential of early enamel caries lesions
El-Gar et al., 2022 [99]	In-vitro	Assessment of biocompatibility and antibiofilm activity of suspension of nHA of large nanoparticle size (NHA-LPS) and nHA -small particle size (NHA-SPS)	NHA-LPS suspension showed enhanced bacterial adhesion and biofilm thickness in compared to NHA-SPS.
Atef et al., 2022 [1 0 0]	In-vitro	Effectiveness of diode laser, fluoride varnish and nHA on the enamel microhardness and microstructural alterations of the primary teeth enamel was assessed	All the remineralizing agents were equally effective in increasing microhardness and maintaining enamel microstructure integrity.
Eliwa et al., 2022 [1 0 1]	In-vitro	Comparison of remineralization potential of nano-seashell, nano-pearl, and nHA pastes with fluoride-based toothpaste.	Enamel surface microhardness was highest in fluoride-based toothpaste, nano pearl paste, nano-seashell paste and nHA.Fluorescence was decreased to greatest in nano-seashell, fluoride-based toothpaste, nHA pastes and least in nano pearls.