Journal of Dental Medicine

The Guided Bone Regeneration (GBR) treatment concept advocates that regeneration of osseous defects is predictably attainable via the application of occlusive membranes, which mechanically exclude non-osteogenic cell populations from the surrounding soft tissues, thereby allowing osteogenic cell populations originating from the parent bone to inhabit the osseous wound. The use of membrane to exclude non-osteogenic cells, is a key principle of guided bone regeneration. A large number of membranes have been evaluated in clinical and experimental studies. The object of this study was to review the literature regarding guided bone regeneration and all types of membranes that were used in this technique. 72 articles between the years 1968 through the 2016 from PubMed, Medline and Google Scholar using the related keywords, were selected. Finally, we concluded that the modification of mechanical and physico-chemical properties of membranes could improve the process of new bone growth. However, determination of the exact role of membrane porosity in this process, still needs to be clarified. Optimization the chemical composition of membrane with the focus and attention to obstructive property and bioactivity, is an important point in this research field. Various factors such as flexibility, mechanical strength and degradation rate determine the type of membrane used for bone tissue regeneration.

Background and Aims: Reconstruction of osseous defects is one of the ideal goals of periodontal treatments and dental implant therapy. Different biomaterials have been used for this purpose and many studies have tried to compare and introduce the best ones. The present study aimed to evaluate the effect of PDFDB (Partially Demineralized Freeze-Dried Bone Graft) and FDBA (Freeze Dried Bone Allograft) on the regeneration of rabbit calvarial defects.
Materials and Methods: In this experimental study, 48 similar defects with the diameter of 8 mm were generated in the calvarium of 16 rabbits. Two defects were filled with FDBA and PDFDB, while the other one remained unfilled as the control group. All defects were covered by collagen membranes. 6 and 12 weeks after surgery, the histologic and histomorphometric tests were performed to evaluate the following variables: the rate of new bone formation and its type, the amount of residual grafting material, degree of inflammation and pattern of bone formation. Comparison of osteogenesis percentage and residual biomaterial was performed by repetitive variance analysis, whereas qualitative variables were compared by Friedman non-parametric test.
Results: Regarding bone formation percentage, there was no statistically significant difference between three different groups at 6-week (P=0.33) and also at 12-week time points (P=0.98). The amount of residual material in the PDFDB group was significantly lower than FDBA (P=0.04) in the 6-week samples. However, this difference was not significant in the 12-week samples (P=0.41). Bone quality showed statistically significant difference between graft containing groups and control group after 12 weeks (P=0.01). It means, all samples in FDBA and PDFDB groups displayed lamellar bone after 12 weeks while in control group, only woven bone or a combination of woven and lamellar bone was seen.
Conclusion: FDBA and PDFDB demonstrated similar regenerating effect in the rabbit calvarial bone defects and hastened bone maturation compared to the non-grafted defects.

Background and Aims: Immediate implant placement following tooth extraction is a treatment with many advantages. Alveolar bone preservation after immediate implant, need minimum of 2 mm thickness in buccal bone plate. The aim of this study was to evaluate the thickness of buccal cortical bone of maxillary premolars by Cone Beam Computational Tomography (CBCT) technique.
Materials and Methods: In this descriptive epidemiological study, Cone Beam Computed Tomography image was obtained from 29 patients (male and female) referred to the radiology department of Jundi Shapoor dental school of Ahvaz from 1393 (Mehr) to 1394 (Shahrivar) for implant insertion insertion. The thickness of buccal cortical bone was measured in 3 and 5 mm apical to the CEJ and root apex, perpendicular to the longitudinal axis. All the measurements were done by two oral and maxillofacial radiologists, separately. Data were analyzed by SPSS22 software, using descriptive statistics, and T-test.
Results: The thickness of buccal cortical bone in second premolar was significantly more than 1 mm (P=0.001), but in first premolar, the thickness was close to 1 mm with a non-significant difference (P=0.29).
Conclusion: The results of this study showed that immediate implant insertion could be done in the maxillary second premolar area with more predictability compared to the first premolar area.