Effects of different biomaterials on augmented bone volume resorptions.

OBJECTIVES: The aim of this study was to assess the effects of platelet-rich fibrin (PRF), deproteinized bovine bone graft (DBBG), and biphasic calcium phosphate (BCP) biomaterials on total volume resorption levels and bone augmentation. MATERIALS AND METHODS: Nine New Zealand rabbits were divided into three groups (PRF, DBBG, and BCP). Two titanium barriers were fixed bilaterally to each rabbit's calvarium; a total of 18 titanium barriers were used. All barriers were removed on the 90th day. Computed tomography (CT) images of the animals were taken on the 90th, 120th, 150th, and 180th days. RESULTS: When the resorption level of the total volume in all groups on the 120th, 150th, and 180th days was compared with that of the 90th day, no significant differences among all groups were found in all intervals. According to the total volume on the 90th and 180th days, statistically significant differences between groups DBBG and BCP were not found; however, statistically significant differences were found between group PRF and the others groups (P < 0.001). On the other hand, there were statistically significant differences in regenerated bone area between group PRF and BCP. CONCLUSION: According to the results of this study, grafts such as DBBG or BCP must be used to augment bone volume sufficiently in guided bone regeneration.

The effect of local simvastatin application on critical size defects in the diabetic rats.

OBJECTIVES: To evaluate bone-healing effects of local simvastatin application to critical size defects (CSDs) in the experimental diabetes mellitus (DM) rat model. MATERIALS AND METHODS: A total of 35 male Sprague-Dawley rats with an average weight of 350 g and aged 3 months were used in this study. The rats were divided into five groups of seven animals each: passive control (group A), active control (group B), 0.5 mg simvastatin (group C), 1.0 mg simvastatin (group D), and 1.5 mg simvastatin (group E). Streptozotocin was used to induce Type 1 diabetes in all rats. Eight mm CSDs were created under anesthesia in each rat calvarium. CSDs were left empty in group A. Defects in group B were grafted alone with a gelatin sponge mixed with normal saline. Defects in the experimental groups (groups A, B, and C) were grafted with gelatin sponge mixed saline solutions contain 0.5, 1.0, 1.5 mg simvastatin. Rats were sacrificed after 1 month, and the defects were prepared for radiologic and histomorphometric assessment of regenerated bone. RESULTS: None of the specimens exhibited complete closure of new bone across the 8-mm defect. A correlation between computed tomography and histomorphometric analysis was not determined. Both amount of volume and area of regenerated bone were found higher in the experimental groups than in the control groups. However, these values were not found statistically significant degree (P < 0.05) for each groups. The density of regenerated bone in the region of interest was higher in the control groups in contrast to in the experimental groups. However, statistical significance was just found between groups C and A and between groups C and B (P < 0.05). CONCLUSION: The local simvastatin application enhanced healing of the bone defects in the diabetic rat model CSDs.

The predominant bacteria isolated from radicular cysts.

PURPOSE: To detect predominant bacteria associated with radicular cysts and discuss in light of the literature. MATERIAL AND METHODS: Clinical materials were obtained from 35 radicular cysts by aspiration. Cultures were made from clinical materials by modern laboratory techniques, they underwent microbiologic analysis. RESULTS: The following are microorganisms isolated from cultures: Streptococcus milleri Group (SMG) (23.8%) [Streptococcus constellatus (19.1%) and Streptococcus anginosus (4.7%)], Streptococcus sanguis (14.3%), Streptococcus mitis (4.7%), Streptococcus cremoris (4.7%), Peptostreptococcus pevotii (4.7%), Prevotella buccae (4.7%), Prevotella intermedia (4.7%), Actinomyces meyeri (4.7%), Actinomyces viscosus (4.7%), Propionibacterium propionicum (4.7%), Bacteroides capillosus (4.7%), Staphylococcus hominis (4.7%), Rothia denticariosa (4.7%), Gemella haemolysans (4.7%), and Fusobacterium nucleatum (4.7%). CONCLUSIONS: Results of this study demonstrated that radicular cysts show a great variety of anaerobic and facultative anaerobic bacterial flora. It was observed that all isolated microorganisms were the types commonly found in oral flora. Although no specific microorganism was found, Streptococcus spp. bacteria (47.5%) - especially SMG (23.8%) - were predominantly found in the microorganisms isolated. Furthermore, radicular cysts might be polymicrobial originated. Although radicular cyst is an inflammatory cyst, some radicular cyst fluids might be sterile.