Sinus Grafting With a Natural Flourohydroxyapatite for Immediate Load: A Study With Histologic Analysis and Histomorphometry
The goal of this retrospective study was to evaluate the survival rates of dental implants placed in sinuses grafted with a 50:50 composite ratio of autogenous bone and a natural flourohydroxyapatite (FHA) combined with platelet-rich plasma (PRP) using an immediate-load protocol. The authors hypothesized that a 50:50 composite ratio of FHA and autogenous bone combined with PRP would permit immediate loading without compromising implant survival rates. Eleven patients with bilateral partial edentulism of the posterior maxilla were enrolled in this retrospective study. Autogenous bone used in the graft procedure was harvested from the tibia of the left lower extremity. Each patient was grafted with a 50:50 composite ratio of autogenous bone and FHA. Membranes were not used to cover the lateral wall osteotomy site. Platelet-rich plasma was added to the graft material to accelerate and enhance bone regeneration. Four to 6 months after the grafting procedure, 37 hydroxyapatite-coated dental implants were surgically placed and immediately loaded between 72 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments. Patients were observed over a 52-week period. The overall implant survival rate was 97.3%. Histologic and histomorphometric analysis of core samples revealed formation of new vital bone in different graft specimens ranging from 23% to 34%. In each core bone sample, 100% of the bone sample was determined to be vital. In the grafted maxillary sinus, the natural FHA combined with autogenous bone in a 50:50 composite ratio with PRP is a suitable graft material permitting immediate load without compromising implant survival rates while decreasing the overall healing time.Abstract

Low-power view of trephine bone core shows multiple, thick autogenous trabeculae and dense cortical bone on the right side and residual flourohydroxyapatite (FHA) graft material (arrows). The double arrows show new autogenous bone formation in contact with FHA graft material (original magnification ×40). Stevenel's blue and van Gieson's picro fuchsin.

New, vital autogenous bone formed around flourohydroxyapatite graft material (arrows; original magnification ×100). Stevenel's blue and van Gieson's picro fuchsin.

High-power view shows new, vital autogenous bone (NB) forming on the surface of flourohydroxyapatite (FHA) graft particles. Osteoid (OS) in contact with the FHA graft material. Osteoblasts (OB; original magnification ×200). Stevenel's blue and van Gieson's picro fuchsin.

(a) High-power view showing new autogenous bone (NB) forming in contact with flourohydroxyapatite (FHA) graft particle. Autogenous bone formation within (intraporous) the cells of the FHA graft material (arrows). No other substitute graft material has demonstrated intraporous bone formation (original magnification ×200). Stevenel's blue and van Gieson's picro fuchsin. (b) High-power view showing autogenous intraporous bone formation within the cells of the FHA graft particle (original magnification ×400). Stevenel's blue and van Gieson's picro fuchsin.