# Clinical Applications of Nano-Hydroxapatite in Dentistry
## 3 Results
### Study Characteristics
#### 3.2.4 Bone Grafts  
[PERSON] et al. [28] employed nano-crystalline HAp for lateral ridge augmentation. The authors observed a significant gain in alveolar ridge width, and no implant failure was registered at 24 months follow-up. It was concluded that lateral augmentation with nano-HAp provided a quantitatively and qualitatively sufficient site for primary stable implant placement. [PERSON] & [PERSON] [29] evaluated nano-structured Mg-enriched HAp covered with covered with a titanium reinforced extended polytetrafluoroethylene membrane for vertical ridge augmentation. Implants were positioned contextually and loaded two weeks later. The authors did not observe implant loss, and inter-implant regenerated bone levels remained stable at 12 and 24 months. Nano-structured Mg-enriched HAp was also used for socket preservation by [PERSON] et al. [30], who found complete regeneration of the alveolar socket at 12 months, with mineralized and well-organized bone tissue around the residual biomaterial particles, although with significant resorption over the observation period. Another study by [PERSON] et al. [31] employed nano-crystalline HAp as bone filler material for sinus grafting prior to implant placement. After 24 months the mean value of radiographic vertical height of grafted sinus was 13.75 mm, and a 97% success rate of functionally loaded implants. The authors concluded that nano-crystalline HAp graft could be used in maxillary sinus lift procedures in cases of early loading, absence of membrane on the buccal wall and low residual bone height. [PERSON] et al. [32] performed sinus lift procedure using a synthetic, nano-porous bone graft material consisting of a mixture of nano-HAp and nano-\(\beta\)-tricalcium phosphate crystals, combined with blood from the defect side. Implant placement was performed immediately or after 4 months. A vertical bone resorption of 10.32% for the one-stage group and 10.82% for the two-stage group was observed at 21.45 months follow-up. Good primary stability was observed at implant placement. The authors concluded the technique was reliable and predictable. [PERSON] et al. [33] compared the quality of bone formation following grafting of the alveolar socket with (i) calcium sulphate, (ii) nano-HAp, (iii) a combination of calcium sulphate and nano-HAp, or (iv) no biomaterial. At 5 months, the percentage of vital bone was significantly higher in the calcium sulphate plus nano-HAp group (58.72% versus 13.56% for the calcium sulphate and 17.84% for the nano-HAp groups). The control group presented the highest percentage of vital bone (80.68%). The authors concluded that the application of either nano-HAp or calcium sulphate resulted in new bone formation at 5 months, with the combination of the two biomaterials showing a higher percentage of bone formation, although inferior compared with the control group. [PERSON] et al. [34] employed nano-HAp derived from eggshell as a graft material in third molar post-extractive sockets. When comparing nano-HAp and control group (no application of biomaterial), 83.33% and 50% of trabecular bone were found respectively, with earlier bone remodeling and complete bone regeneration being observed in the nano-HAp group. [PERSON] et al. [35] compared the outcomes of nano-HAp versus graftless tenting technique with simultaneous implant placement in sinus lift. Bone gain with nano-HAp was significantly higher compared with control group (7.0 mm and 5.0 mm, respectively). Significantly higher bone density and implant stability were also observed for the nano-HAp group. \begin{table}
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