Sustained Release of Vitamin D3 Enhanced Osseointegration Capacity: An Experimental Sheep Study

Abstract

Abstract: This study aimed to investigate the effect of sustained-release vitamin D loaded in poly-lacticacid (PLA) nanoparticles and applied to grafting materials around titanium (ti) dental implants.A total of 48 implants were inserted into the standardized bone defects created in the iliac crest of 6sheep, divided into 4 different experimental sites (empty control, autografted, xenografted, andautograft + xenografted). Vitamin D3, which was encapsulated by PLA nanoparticles, was preparedand applied in half of the defects and left to heal for 3 and 6 weeks. New bone formation (NBF%) andbone-implant contact (BIC%) values were evaluated by histologic and histomorphometric analyses (P< 0.05). Nanoparticles with a yield of 80.30% ± 2.14% and high encapsulation efficiency of 72.99% ±2.20% were achieved. In all sections, osseointegration was observed, with no signs of inflammation,necrosis, or foreign body reaction. NBF% and BIC% were significantly higher in vitamin D3–loadedgroups (P < 0.001). In both healing periods, the highest NBF% and BIC% have been recorded in theautograft + xenograft groups. (For the respective third and sixth weeks: the NBF% was 49.63 ± 1.53and 74.25 ± 0.96, and BIC% was 54.26 ± 0.66 and 82.59 ± 2.09, respectively; P < 0.001). Sustainedreleaseof vitamin D loaded into the PLA system demonstrated high biocompatibility, favorablesustained release of vitamin D3, and improved NBF% and BIC% around ti implants placed in boxshapedsheep iliac crest defects. Further investigations are required for their clinical applicability.Keywords: autograft; dental implant; osseointegration; poly-lactic acid; sustained release; vitamin D3;xenograft.