Alveolar Ridge Preservation Utilizing Composite (Bioceramics/Collagen) Graft: A Cone-Beam Computed Tomography Assessment in a Randomized Split-Mouth Controlled Trial

Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction;however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order to prevent this reduction or at least recompense the loss of bone dimensions, the alveolar ridge preservation (ARP) technique was developed. Objectives: This research studied the vertical and horizontal bone dimensional changes as a result of non-molar teeth extraction alone against extraction with alveolar ridge preservation utilizing composite (bioceramics/collagen) graft by cone-beam computed tomography radiographies analyses. Material and Methods: This research was a randomized split-mouth controlled trial. 12 patients need extraction of the maxillary non-molar teeth were enrolled and allocated into 2 groups. 12 sockets after atraumatic extraction were filled with a composite graft in the role of the test group, 12 sockets left to unassisted healing after atraumatic extraction without any graft materials in the role of the control group. Two CBCT radiographs were taken at baseline and at 4 months after extraction for comparison. Both vertical and horizontal resorptions of the alveolar ridge were analyzed between test and control group by CBCT radiographs. Results: 4 months after extraction, there was a mean of vertical alveolar bone resorption compared with the baseline (0.56 ± 0.15 mm) in the test group and (1.47 ± 0.30 mm) in the control group. Whereas it was a mean of horizontal alveolar bone resorption compared with the baseline (0.90 ± 0.16 mm) in the test group and (2.26 ± 0.30 mm) in the control group. Therefore, there was a significant difference between the two groups. Conclusions: Within the limitations of this research, we demonstrated that the osteogen-plug technique significantly decreased the reduction of the bone dimensional in comparison to the tooth extraction alone, and showed that the dimensional change of the alveolar ridge after tooth extraction was minimized by using an osteogen-plug.

A new method to standardize CBCT for quantitative evaluation of alveolar ridge preservation in the mandible:a case report and review of the literature

Cone-beam computerized tomography(CBCT)is an effective technique for assessment of changes to the alveolar ridge(AR).However,its accuracy and reliability could be improved by standardization of imaging positions to remain unchanged during measurements.In this study,an alveolar ridge preservation procedure was performed on a left third molar(38)socket by filling it with a radiotransparent synthetic bone graft,mineralized collagen(MC).Photographic,X-ray and CBCT images were captured before and 3,6 and 12 months after surgery.A new method was developed to standardize CBCT for quantitative evaluation.Obtained CBCT images showed good comparability.The post-extraction alveolar width and height were both over 95%of the original values,but some resorption of the lingual bone wall(>50%)and inter-crestal bone(>30%).It is concluded that an effective positional standardization method was developed for CBCT assessment of AR dimensional changes in the posterior mandible.The use of MC in combination with a collagen membrane improved dimensional preservation of the AR.

Polyphosphate-crosslinked collagen scaffolds for hemostasis and alveolar bone regeneration after tooth extraction

Post-extraction bleeding and alveolar bone resorption are the two frequently encountered complications after tooth extraction that result in poor healing and rehabilitation difficulties.The present study covalently bonded polyphosphate onto a collagen scaffold(P-CS)by crosslinking.The P-CS demonstrated improved hemostatic property in a healthy rat model and an anticoagulant-treated rat model.This improvement is attributed to the increase in hydrophilicity,increased thrombin generation,platelet activation and stimulation of the intrinsic coagulation pathway.In addition,the P-CS promoted the in-situ bone regeneration and alveolar ridge preservation in a rat alveolar bone defect model.The promotion is attributed to enhanced osteogenic differentiation of bone marrow stromal cells.Osteogenesis was improved by both polyphosphate and blood clots.Taken together,P-CS possesses favorable hemostasis and alveolar ridge preservation capability.It may be used as an effective treatment option for post-extraction bleeding and alveolar bone loss.Statement of significance:Collagen scaffold is commonly used for the treatment of post-extraction bleeding and alveolar bone loss after tooth extraction.However,its application is hampered by insufficient hemostatic and osteoinductive property.Crosslinking polyphosphate with collagen produces a modified collagen scaffold that possesses improved hemostatic performance and augmented bone regeneration potential.

Comparison of bone regeneration in alveolar bone of dogs on mineralized collagen grafts with two composition ratios of nanohydroxyapatite and collagen

To study the effect of two composition ratios of nano-hydroxyapatite and collagen(NHAC)composites on repairing alveolar bone defect of dogs.Eighteen healthy adult dogs were randomly divided into three groups.Two kinds of the NHAC composites were prepared according to the constituent ratios of 3:7 and 5:5;immediately after extraction of the mandibular second premolars,each kind of the NHAC composite was implanted into extraction socket,respectively:Group I,nHA/Col紏3:7;Group II,nHA/Col紏5:5 and Group III,blank control group.The bone-repairing ability of the two grafts was separately analyzed by morphometric measurement,X-ray tomography examination and biomechanical analysis at 1st,3rd and 6th month post-surgical,respectively.The NHAC composites were absorbed gradually after implanting into alveolar bone defect and were replaced by new bone.The ratios of new bone formation of Group I was significantly higher than that of Group II after 3 months(P<0.05).The structure and bioactive performance can be improved when the ratio between the collagen and the hydroxyapatite was reasonable,and the repairing ability and effect in extraction sockets are obviously better.