Natural coral as bone-defect-filling material

Abstract

Natural coral (NC) has been studied experimentally and clinically as a bone substitute, but its resorption rate and possible replacement by bone still need to be defined in humans. In this study bicortical bone was harvested from the iliac crest of 10 patients. The defect was filled with a NC block, and changes were monitored by X-rays and quantitative CT scans for a mean of 2.1 years. A biopsy was taken at 1 year. The purpose of the study was to investigate the resorption rate and pattern of NC (Porites) implants and the replacement, if any, of the implant by new bone. The blocks underwent centripetal resorption, but all the blocks still could be detected by X-rays and CT scans at the end of the follow-up period. The density of the remaining block did not change. Seven of the 10 implants were smaller than 50% of their original size at the end of the study. Bone ingrowth could be observed only in two of seven biopsies. One implant had to be removed after 1.7 years due to infection. The study shows that resorption of natural coral proceeds centripetally and apparently more rapidly when accompanied by tissue ingrowth. None of the blocks resorbed completely, and the defect at the iliac crest had not been restored by the end of the study.

Is there a role of coral bone substitutes in bone repair?

“…67 Clinical studies utilizing Biocoral ® have shown mixed results. [74][75][76][77][78][79][80][81][82][83] Early studies have utilized Biocoral ® in the treatment of bony maxillofacial defects. Of interest is the study of Roux et al presented the outcome of this product in 183 patients.…”

The healing of confined critical size cancellous defects in the presence of silk fibroin hydrogel

“…Many different materials have been used or proposed for bone replacement or repair, such as metals, collagen, glass ceramics, calcium sulphate, natural and synthetic calcium phosphate ceramics, polymers, and cements [8][9][10][11].…”

Preparation, physical–chemical characterisation and cytocompatibility of calcium carbonate cements

“…Many surgeons use bone hetero-or autografts or implants of natural origin (coral for example) [1][2][3][4][5][6]. However, supply difficulty, biological variability and viral or bacterial contamination risks are major drawbacks [6][7]. In order to solve the problems inherent to substitution with natural biomaterials, synthetic materials have been developed as biomedical ceramics and cements [8].…”

“…The mechanical properties of coral-based graft substitute remain poor and implant rejection can occur probably due to the presence of organic matter residue [7,40]. Although several attempts have been made to produce synthetic calcium carbonate bioceramics, sintering proves to be difficult and calcium carbonate cements, prepared by mixing calcium carbonate phases with an aqueous medium, offer an interesting way to prepare low-temperature bioceramics [41][42].…”