Bone-defects healing by high-molecular hyaluronic acid: preliminary results

Abstract

AIM.: The aim of this study is to evaluate the capability of Hyaloss™ matrix (Fab - Fidia Advanced Biopolymers - Pd - Italy), a biomaterial based on hyaluronic acid, used as organic scaffold in bone repair in post-extractive defects.

Materials and methods: 20 post-extractive sockets were selected, with similar size defects in the same patient and in the same hemiarch. Hyaluronic acid with high molecular weight (Hyaloss™ matrix, Fab - Pd - Italy) was mixed with autologous bone obtained using Safescraper(®) curve (Meta - Re - Italy) to repair post-extractive sites. Safescraper(®) is a cutting edge system that allows to the collection of autologous bone without using traditional, incision-based collection techniques, which could cause discomfort to the patient.

Results: Clinical and hystological evaluations were performed, four months after grafting, in the maxilla and in the mandible. From a clinical point of view Hyaloss™ matrix mixed with autologous bone and patient's blood becomes a substance similar to gel, which is easy to insert in to the defect. From a hystological point of view, in the treated site there is the presence of an erosive activity, with accelerated angiogenetic and bone remodelling activities.

Conclusions: The preliminary results show an acceleration of the bone deposit process and of its remodelling due to the presence of Hyaloss™ matrix, which, from a clinical point of view, improves the handling and application of the bone matrix inside the defects and, from a hystologic point of view makes it possible to obtain bone regeneration in less time when it is used with autologous bone.

Keywords: autologous bone; bone; bone defect healing; bone graft; hyaluronic acid.

Figures

Figure 1

Hyaluronic acid.

Figure 2

Hyaff’s molecule.

Figure 3

Radiographic control of two post extractive sites before the grafting.

Figure 4

Safescraper device for bone harvesting near the bone defect.

Figure 5

Autologous cortical bone mixed with hyaluronic acid ready to be inserted in to the bone socket.

Figure 6

The implants (Swiss Plus 3,75x12 mm) at 3 months grafting. The mesial implant is the control case (only cortical autologous bone), the distal implant is the treated case (autologous cortical bone and hyaluronic acid).

Figures 7 and 8

(Hyaloss) Microradiographies of biopsies from maxillary post-extractive sites of the same patient, 4 months after grafting. The control shows an amount of bone higher than the Hyaloss treated site. Microradiography of the biopsy of the Hyaloss treated site: we can observe that the bone trabeculae seem to be particularly thick but show a large amount of vascular neo-cavities.

Figures 7 and 8

(Hyaloss) Microradiographies of biopsies from maxillary post-extractive sites of the same patient, 4 months after grafting. The control shows an amount of bone higher than the Hyaloss treated site. Microradiography of the biopsy of the Hyaloss treated site: we can observe that the bone trabeculae seem to be particularly thick but show a large amount of vascular neo-cavities.

Figure 9

Toluidine blue staining highlights living osteocytes (black arrow) both in newly formed bone and in grafted autologous bone.

Figure 10

Microradiography of the biopsy of the Hyaloss treated site. Note the several bone layers formed on the grafted autologous cortical bone. Osteoclasts resorb the new, old or recently formed bone and the grafted autologous bone. Microradiographies of the external part of bone trabecula in a biopsy of the Hyaloss treated site. The solochrome cyanine/nuclear fast red staining highlights living osteocytes both in the grafted autologous bone (arrows – bottom) and in the newly formed bone. In the control sites, on the contrary, the new bone, formed in apposition to the grafted autologous bone, shows many parts with lamellar structures.