Date Published: June 5, 2018
Publisher: Public Library of Science
Author(s): Ricardo Coringa, Eduardo Martins de Sousa, Juliana Nunes Botelho, Rafael Soares Diniz, Joicy Cortez de Sá, Maria Carmen Fontoura Nogueira da Cruz, Marco Aurelio Beninni Paschoal, Letícia Machado Gonçalves, Dominique Heymann.
Despite their demonstrated biocompatibility and osteogenic properties, oyster shells have been reported as a potential alternative to other commonly used materials for bone substitution. This study evaluated whether an experimental bone substitute (EBS) made from a typical oyster shell of Northeastern Brazil (Crassostrea rhizophora) has effects on bone development using an animal model. Oysters were collected from a biologically assisted vivarium, and their inner layer was used for preparing an EBS. Chemical and surface characterization of EBS was performed using Individually Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Scanning Electron Microscope (SEM), respectively. Seventy-two rats were randomly assigned to groups according to the treatment of bone defects created in the submandibular area: Negative Control (-C), Positive Control (+C; Bio-Oss®) and EBS. Euthanasia occurred at 7, 21, 42 and 56 days postoperatively. The bone pieces were stained with hematoxylin and eosin (H&E). The formation of bone tissue was evaluated histologically and histomorphometrically. Data were analyzed through the Kruskal-Wallis test and ANOVA considering a significant level of 5%. The main element found in EBS was calcium (71.68%), and it presented heterogeneity in the particle size and a porosity aspect at SEM analysis. Histological results revealed the absence of inflammatory cells in all groups, being that EBS presented the most accelerated process of bone formation with a statistically significant difference between this group and the +C and -C groups in the 21-day time-point (p < 0.05). After 21 days, the bone formation process was similar between all groups (p > 0.05), showing an immature lamellar bone pattern after 56 days of experimentation (p > 0.05). Within the limitations of this study, it was possible to conclude that EBS presented good biocompatibility and promoted fast stimulation for bone-forming cells in an animal model.
Implant rehabilitation in partially or totally edentulous patients has become a common practice with predictable long-term results [1–3]. However, edentulism provided by periodontal disease, trauma, malformations or neoplasms can lead to bone atrophies and insufficient bone quantity and/or quality for implant placement . In these cases, ridge augmentation is required to correct the unfavorable bone volume, which can be accomplished with the use of bone grafts and bone-graft substitutes, used individually or combined [2,5–7].
An increase in tissue engineering has been noticed in the search for an ideal bone substitute [5–7]. Despite its demonstrated biocompatibility, biodegradability and osteogenic properties, nacre from oyster shells has been reported as a potential alternative to other commonly used materials for bone substitution [12,21–26]. Also, the use of oyster shells for bone grafting provides evidence with self-sustaining development that may reduce the cost for final rehabilitation treatment. Here we investigated the potential of a typical oyster shell of Northeastern Brazil (C. rhizophora) as a bone substitute.
Within the limitations of this first study, it was possible to conclude that EBS presented good biocompatibility and promoted fast stimulation for bone-forming cells in an animal model.