Do perioperative antibiotics reduce complications of mandibular third molar removal? A double-blind randomized controlled clinical trial.

OBJECTIVE: The aim of this study was to compare the effects of different antibiotic prophylaxis regimens versus placebo in relation to possible postoperative complications derived from the surgical extraction of impacted lower third molars. STUDY DESIGN: The final study sample of this double-blind randomized controlled trial comprised 92 Caucasian volunteers. Patients were assigned to 3 groups by using a randomization table. Group 1 (n = 30) received 750 mg oral amoxicillin both before and after the surgery; group 2 (n = 32) received the same oral dose after surgery alone; and group 3 (n = 30) received placebo both before and after surgery. Infectious complications, postoperative pain, and inflammation intensity were measured. The requirement for and the timing of rescue medication were also measured. RESULTS: Postoperative pain and inflammation intensity were significantly higher (P < .05) in group 3 than in groups 1 or 2 at 48 hours, 72 hours, and 1 week. A significantly higher proportion of group 3 required rescue medication (analgesics and rescue antibiotics) (P = .013) compared with groups 1 or 2. CONCLUSIONS: Greater pain and inflammation were experienced by patients receiving placebo before lower third molar extraction than by those receiving antibiotics either before surgery or both before and after surgery. Other options, such as use of local antibiotics, should be considered to reduce the problems, including bacterial resistance, caused by overuse of systemic antibiotics.

Factors Affecting Dental Implant Stability Measured Using the Ostell Mentor Device: A Systematic Review.

OBJECTIVES: The aim of this study was to review the literature on factors that may affect dental implant stability as measured with the Ostell mentor device. MATERIALS AND METHODS: A systematic search of the literature was performed in Pubmed, Scopus, and Cochrane databases using dental implants, stability, and resonance frequency analysis as key words. RESULTS: The most relevant randomized controlled trials and clinical trials (n = 39) were selected from among 264 articles. CONCLUSIONS: Many factors can affect dental implant stability as measured with the Ostell mentor device. This may be a useful instrument for deciding the timing of implant loading, but additional research is required to establish the reliability and predictability of resonance frequency analysis for the future osseointegration of dental implants, which remains controversial.

Bacterial contamination levels of autogenous bone particles collected by 3 different techniques for harvesting intraoral bone grafts.

PURPOSE: The aim of this study was to compare levels of bacterial contamination of autogenous bone collected when using low-speed drilling, a back-action chisel, and a bone filter. MATERIALS AND METHODS: Bone tissue samples were taken from 31 patients who underwent surgical extraction of their third lower molars. Before surgical removal of the molar, bone particles were collected by a low-speed drill or a back-action chisel. Then, a stringent aspiration protocol was applied during the ostectomy to collect particulate bone by a bone filter. Processing of samples commenced immediately by incubation in an anaerobic or a CO2-rich atmosphere. The number of colony-forming units (CFUs) was determined at 48 hours of culture. RESULTS: No significant difference in the number of CFUs per milliliter was observed between the low-speed drilling group and the back-action chisel group in the anaerobic or CO2-rich condition (P = .34). However, significantly more micro-organisms were found in the bone filter group than in the low-speed drilling group or the back-action chisel group in the anaerobic and CO2-rich conditions (P < .001). CONCLUSIONS: Particulate bone harvested with low-speed drilling or a back-action chisel is safer for use as an autograft than are bone particles collected with a bone filter. These results suggest that bone obtained from low-speed drilling is safe and straightforward to harvest and could be the method of choice for collecting particulate bone. Further research is needed to lower the bacterial contamination levels of autogenous bone particles used as graft material.

Effect of different growth factors on human cultured osteoblast-like cells.

BACKGROUND/AIMS: Proliferation and differentiation of osteoblast-like cells are regulated by complex interactions among systemic hormones, cytokines, and local growth factors. The success of oral rehabilitation using biomaterial implants depends on the growth of osteoblasts and their adhesivity to the surface of the implant. The study aimed to investigate the effect of different growth factors on the proliferation and adhesivity of human osteoblast-like cells in vitro. METHODS: The effects of transforming growth factor beta1 (TGFbeta1), fibroblast growth factor (FGF), and interleukin-2 (IL-2) on the growth and adhesivity of human osteoblast-like cells in monolayer culture were studied. Their growth was measured by (3)H-thymidine incorporation and their adhesivity by flow cytometry. RESULTS: Incorporation of (3)H-thymidine was increased by all growth factors. The effect did not appear to be dose dependent. No synergic effect was found between TGFbeta1 and FGF. Treatment with TGFbeta1 or FGF increased cell adhesivity by shortening the time needed for cell adhesion to the culture dish surface and hydroxyapatite-coated implants. IL-2 did not modify cell adhesivity. CONCLUSIONS: Growth factors can modulate cell proliferation and adhesivity, which may help to increase the success of implantation therapy.

Antigenic phenotype of cultured human osteoblast-like cells.

BACKGROUND/AIMS: Osteoblasts are classically considered to play an important role during bone tissue development, and to be involved in the formation of mineralized bone matrix. Recent reports have suggested that they can also exert some activities directly associated with the immune system (cytokine synthesis and antigen presentation). Moreover, some authors have found antigens on osteoblast-like cells normally expressed by other cells with a common origin in bone marrow. METHODS: We isolated and cultured human osteoblast-like lines and studied their antigenic phenotype with flow cytometry using monoclonal antibodies against antigens associated with hematopoietic cells. RESULTS: Cultured cells expressed CD34, but were negative for CD45. B cell antigens CD20 and CD23 and myelomonocytic antigens CD11b, CD13, and CD16 were detected. Expression of CD3, CD14, CD15 and CD68 was negative, whereas CD25 expression was positive. CD56, an antigen expressed on NK cells, was positive. These cells were CD10, CD44, CD54, CD80, CD86 and HLA-DR positive, as previously described. An antigen specific to follicular dendritic cells was also observed on cultured osteoblast-like cells. CONCLUSIONS: The antigenic phenotypes of human osteoblast-like cells and FDC are similar. These data suggest that osteoblasts may be functionally related to certain dendritic cells and may play an additional role in bone tissue to that classically assigned.