Background After tooth extraction the alveolar ridge undergoes considerable volumetric and qualitative changes. A volumetric decrease of 35% versus 60% is expected in case of adequate or compromised socket extractions. Alveolar Ridge Preservation procedures strive for controlling the ridge changes after tooth extraction. Regardless of biomaterial used and of technique performed, this procedure cannot fully counteract tissue changes after tooth extraction. Aim/Hypothesis The primary aim of this study was to evaluate the histologic outcomes 3 months after ridge preservation performed with an allograft and a flapless technique in compromised sockets. The secondary aims were to evaluate the need for GBR and the clinical dimensional changes at implant placement. Material and Methods Thirteen patients (mean age 54.9 ± 5.7 years), who required a single tooth extraction and who had a compromised extraction socket, were enrolled in this prospective cohort study. The tooth extraction was flapless, the extraction sockets were grafted with an allograft (FDBA) and covered with a collagen membrane. All the sites had a secondary soft tissue healing. After 3 months of healing all patients received an implant in an ideal prosthetic position. At implant placement bone biopsies for histologic analysis and linear clinical measurements were taken. The bone samples (n = 13) were fixed in 10% neutral buffered formalin and dehydrated in an ascending series of alcohol rinses, and, subsequently, embedded in a glycolmethacrylate resin (Technovit 7200 VLC, Kulzer, Wehrheim, Germania). All specimens were sectioned along their longitudinal axis, were grounded down to 30 microns and stained with acid fuchsin and toluidine blue. Histologic and Histomorphometric evaluations were carried out. Results No post‐grafting adverse events were observed and all sites healed uneventfully. The 13 implants were placed in 6 molar, 6 premolar and 1 incisal sites. All implants were placed in an ideal prosthetic position and no implants required any additional augmentation procedures at the placement. The crestal width changes were 2.1 ± 1.3 mm, the width of keratinized tissue had an increase of 0.7 ± 09 mm. The histologic findings revealed that the graft particles were found close to the pre‐existing bone and showed an evident remodeling process+ in addition all particles were completely surrounded by newly formed bone. It is worth noting that osteoblasts deposing osteoid matrix directly on the particle surface were observed in several fields. The marrow spaces were rich of small blood vessels that were close both to newly formed bone and residual graft particles. Histomorphometry showed that newly formed bone represented 26.9%, marrow spaces 52.2%, and residual graft material 20.9%. Conclusion and Clinical Implications The findings from this preliminary study showed that FDBA and collagen resorbable membrane‐ used to graft compromised fresh extraction sockets‐ were clinically effective. Three months after tooth extraction this procedure allowed an ideal implant prosthetic placement without any adjunctive augmentation procedures. The histologic and histomorphometric outcomes showed a graft biomaterial able to be remodeled in a short time frame allowing the formation of a good amount of well vascularized bone.

Histologic outcomes of ridge preservation with an allograft in humans: a cohort prospective study

Vittoria Perrotti;Giovanna Iezzi;
2019

Abstract

Background After tooth extraction the alveolar ridge undergoes considerable volumetric and qualitative changes. A volumetric decrease of 35% versus 60% is expected in case of adequate or compromised socket extractions. Alveolar Ridge Preservation procedures strive for controlling the ridge changes after tooth extraction. Regardless of biomaterial used and of technique performed, this procedure cannot fully counteract tissue changes after tooth extraction. Aim/Hypothesis The primary aim of this study was to evaluate the histologic outcomes 3 months after ridge preservation performed with an allograft and a flapless technique in compromised sockets. The secondary aims were to evaluate the need for GBR and the clinical dimensional changes at implant placement. Material and Methods Thirteen patients (mean age 54.9 ± 5.7 years), who required a single tooth extraction and who had a compromised extraction socket, were enrolled in this prospective cohort study. The tooth extraction was flapless, the extraction sockets were grafted with an allograft (FDBA) and covered with a collagen membrane. All the sites had a secondary soft tissue healing. After 3 months of healing all patients received an implant in an ideal prosthetic position. At implant placement bone biopsies for histologic analysis and linear clinical measurements were taken. The bone samples (n = 13) were fixed in 10% neutral buffered formalin and dehydrated in an ascending series of alcohol rinses, and, subsequently, embedded in a glycolmethacrylate resin (Technovit 7200 VLC, Kulzer, Wehrheim, Germania). All specimens were sectioned along their longitudinal axis, were grounded down to 30 microns and stained with acid fuchsin and toluidine blue. Histologic and Histomorphometric evaluations were carried out. Results No post‐grafting adverse events were observed and all sites healed uneventfully. The 13 implants were placed in 6 molar, 6 premolar and 1 incisal sites. All implants were placed in an ideal prosthetic position and no implants required any additional augmentation procedures at the placement. The crestal width changes were 2.1 ± 1.3 mm, the width of keratinized tissue had an increase of 0.7 ± 09 mm. The histologic findings revealed that the graft particles were found close to the pre‐existing bone and showed an evident remodeling process+ in addition all particles were completely surrounded by newly formed bone. It is worth noting that osteoblasts deposing osteoid matrix directly on the particle surface were observed in several fields. The marrow spaces were rich of small blood vessels that were close both to newly formed bone and residual graft particles. Histomorphometry showed that newly formed bone represented 26.9%, marrow spaces 52.2%, and residual graft material 20.9%. Conclusion and Clinical Implications The findings from this preliminary study showed that FDBA and collagen resorbable membrane‐ used to graft compromised fresh extraction sockets‐ were clinically effective. Three months after tooth extraction this procedure allowed an ideal implant prosthetic placement without any adjunctive augmentation procedures. The histologic and histomorphometric outcomes showed a graft biomaterial able to be remodeled in a short time frame allowing the formation of a good amount of well vascularized bone.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11564/722752
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